--- /dev/null
- INIT_COMPLETION(dev->done);
+ /*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+ #include <linux/device.h>
+ #include <linux/kernel.h>
+ #include <linux/module.h>
+ #include <linux/sched.h>
+ #include <linux/i2c.h>
+ #include <linux/interrupt.h>
+ #include <linux/platform_device.h>
+ #include <linux/clk.h>
+ #include <linux/io.h>
+ #include <linux/clk.h>
+ #include <linux/slab.h>
+
+ /* Hardware register offsets and field defintions */
+ #define CS_OFFSET 0x00000020
+ #define CS_ACK_SHIFT 3
+ #define CS_ACK_MASK 0x00000008
+ #define CS_ACK_CMD_GEN_START 0x00000000
+ #define CS_ACK_CMD_GEN_RESTART 0x00000001
+ #define CS_CMD_SHIFT 1
+ #define CS_CMD_CMD_NO_ACTION 0x00000000
+ #define CS_CMD_CMD_START_RESTART 0x00000001
+ #define CS_CMD_CMD_STOP 0x00000002
+ #define CS_EN_SHIFT 0
+ #define CS_EN_CMD_ENABLE_BSC 0x00000001
+
+ #define TIM_OFFSET 0x00000024
+ #define TIM_PRESCALE_SHIFT 6
+ #define TIM_P_SHIFT 3
+ #define TIM_NO_DIV_SHIFT 2
+ #define TIM_DIV_SHIFT 0
+
+ #define DAT_OFFSET 0x00000028
+
+ #define TOUT_OFFSET 0x0000002c
+
+ #define TXFCR_OFFSET 0x0000003c
+ #define TXFCR_FIFO_FLUSH_MASK 0x00000080
+ #define TXFCR_FIFO_EN_MASK 0x00000040
+
+ #define IER_OFFSET 0x00000044
+ #define IER_READ_COMPLETE_INT_MASK 0x00000010
+ #define IER_I2C_INT_EN_MASK 0x00000008
+ #define IER_FIFO_INT_EN_MASK 0x00000002
+ #define IER_NOACK_EN_MASK 0x00000001
+
+ #define ISR_OFFSET 0x00000048
+ #define ISR_RESERVED_MASK 0xffffff60
+ #define ISR_CMDBUSY_MASK 0x00000080
+ #define ISR_READ_COMPLETE_MASK 0x00000010
+ #define ISR_SES_DONE_MASK 0x00000008
+ #define ISR_ERR_MASK 0x00000004
+ #define ISR_TXFIFOEMPTY_MASK 0x00000002
+ #define ISR_NOACK_MASK 0x00000001
+
+ #define CLKEN_OFFSET 0x0000004C
+ #define CLKEN_AUTOSENSE_OFF_MASK 0x00000080
+ #define CLKEN_M_SHIFT 4
+ #define CLKEN_N_SHIFT 1
+ #define CLKEN_CLKEN_MASK 0x00000001
+
+ #define FIFO_STATUS_OFFSET 0x00000054
+ #define FIFO_STATUS_RXFIFO_EMPTY_MASK 0x00000004
+ #define FIFO_STATUS_TXFIFO_EMPTY_MASK 0x00000010
+
+ #define HSTIM_OFFSET 0x00000058
+ #define HSTIM_HS_MODE_MASK 0x00008000
+ #define HSTIM_HS_HOLD_SHIFT 10
+ #define HSTIM_HS_HIGH_PHASE_SHIFT 5
+ #define HSTIM_HS_SETUP_SHIFT 0
+
+ #define PADCTL_OFFSET 0x0000005c
+ #define PADCTL_PAD_OUT_EN_MASK 0x00000004
+
+ #define RXFCR_OFFSET 0x00000068
+ #define RXFCR_NACK_EN_SHIFT 7
+ #define RXFCR_READ_COUNT_SHIFT 0
+ #define RXFIFORDOUT_OFFSET 0x0000006c
+
+ /* Locally used constants */
+ #define MAX_RX_FIFO_SIZE 64U /* bytes */
+ #define MAX_TX_FIFO_SIZE 64U /* bytes */
+
+ #define STD_EXT_CLK_FREQ 13000000UL
+ #define HS_EXT_CLK_FREQ 104000000UL
+
+ #define MASTERCODE 0x08 /* Mastercodes are 0000_1xxxb */
+
+ #define I2C_TIMEOUT 100 /* msecs */
+
+ /* Operations that can be commanded to the controller */
+ enum bcm_kona_cmd_t {
+ BCM_CMD_NOACTION = 0,
+ BCM_CMD_START,
+ BCM_CMD_RESTART,
+ BCM_CMD_STOP,
+ };
+
+ enum bus_speed_index {
+ BCM_SPD_100K = 0,
+ BCM_SPD_400K,
+ BCM_SPD_1MHZ,
+ };
+
+ enum hs_bus_speed_index {
+ BCM_SPD_3P4MHZ = 0,
+ };
+
+ /* Internal divider settings for standard mode, fast mode and fast mode plus */
+ struct bus_speed_cfg {
+ uint8_t time_m; /* Number of cycles for setup time */
+ uint8_t time_n; /* Number of cycles for hold time */
+ uint8_t prescale; /* Prescale divider */
+ uint8_t time_p; /* Timing coefficient */
+ uint8_t no_div; /* Disable clock divider */
+ uint8_t time_div; /* Post-prescale divider */
+ };
+
+ /* Internal divider settings for high-speed mode */
+ struct hs_bus_speed_cfg {
+ uint8_t hs_hold; /* Number of clock cycles SCL stays low until
+ the end of bit period */
+ uint8_t hs_high_phase; /* Number of clock cycles SCL stays high
+ before it falls */
+ uint8_t hs_setup; /* Number of clock cycles SCL stays low
+ before it rises */
+ uint8_t prescale; /* Prescale divider */
+ uint8_t time_p; /* Timing coefficient */
+ uint8_t no_div; /* Disable clock divider */
+ uint8_t time_div; /* Post-prescale divider */
+ };
+
+ static const struct bus_speed_cfg std_cfg_table[] = {
+ [BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
+ [BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
+ [BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
+ };
+
+ static const struct hs_bus_speed_cfg hs_cfg_table[] = {
+ [BCM_SPD_3P4MHZ] = {0x01, 0x08, 0x14, 0x00, 0x06, 0x01, 0x00},
+ };
+
+ struct bcm_kona_i2c_dev {
+ struct device *device;
+
+ void __iomem *base;
+ int irq;
+ struct clk *external_clk;
+
+ struct i2c_adapter adapter;
+
+ struct completion done;
+
+ const struct bus_speed_cfg *std_cfg;
+ const struct hs_bus_speed_cfg *hs_cfg;
+ };
+
+ static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
+ enum bcm_kona_cmd_t cmd)
+ {
+ dev_dbg(dev->device, "%s, %d\n", __func__, cmd);
+
+ switch (cmd) {
+ case BCM_CMD_NOACTION:
+ writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_START:
+ writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
+ (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_RESTART:
+ writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
+ (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ case BCM_CMD_STOP:
+ writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
+ (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+ dev->base + CS_OFFSET);
+ break;
+
+ default:
+ dev_err(dev->device, "Unknown command %d\n", cmd);
+ }
+ }
+
+ static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
+ {
+ writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+ }
+
+ static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
+ {
+ writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+ }
+
+ static irqreturn_t bcm_kona_i2c_isr(int irq, void *devid)
+ {
+ struct bcm_kona_i2c_dev *dev = devid;
+ uint32_t status = readl(dev->base + ISR_OFFSET);
+
+ if ((status & ~ISR_RESERVED_MASK) == 0)
+ return IRQ_NONE;
+
+ /* Must flush the TX FIFO when NAK detected */
+ if (status & ISR_NOACK_MASK)
+ writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+ dev->base + TXFCR_OFFSET);
+
+ writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
+ complete_all(&dev->done);
+
+ return IRQ_HANDLED;
+ }
+
+ /* Wait for ISR_CMDBUSY_MASK to go low before writing to CS, DAT, or RCD */
+ static int bcm_kona_i2c_wait_if_busy(struct bcm_kona_i2c_dev *dev)
+ {
+ unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
+
+ while (readl(dev->base + ISR_OFFSET) & ISR_CMDBUSY_MASK)
+ if (time_after(jiffies, timeout)) {
+ dev_err(dev->device, "CMDBUSY timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+ }
+
+ /* Send command to I2C bus */
+ static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
+ enum bcm_kona_cmd_t cmd)
+ {
+ int rc;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+ /* Make sure the hardware is ready */
+ rc = bcm_kona_i2c_wait_if_busy(dev);
+ if (rc < 0)
+ return rc;
+
+ /* Unmask the session done interrupt */
+ writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+ /* Mark as incomplete before sending the command */
- INIT_COMPLETION(dev->done);
++ reinit_completion(&dev->done);
+
+ /* Send the command */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
+
+ /* Wait for transaction to finish or timeout */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_err(dev->device, "controller timed out\n");
+ rc = -ETIMEDOUT;
+ }
+
+ /* Clear command */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+ return rc;
+ }
+
+ /* Read a single RX FIFO worth of data from the i2c bus */
+ static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
+ uint8_t *buf, unsigned int len,
+ unsigned int last_byte_nak)
+ {
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+
+ /* Mark as incomplete before starting the RX FIFO */
- INIT_COMPLETION(dev->done);
++ reinit_completion(&dev->done);
+
+ /* Unmask the read complete interrupt */
+ writel(IER_READ_COMPLETE_INT_MASK, dev->base + IER_OFFSET);
+
+ /* Start the RX FIFO */
+ writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
+ (len << RXFCR_READ_COUNT_SHIFT),
+ dev->base + RXFCR_OFFSET);
+
+ /* Wait for FIFO read to complete */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_err(dev->device, "RX FIFO time out\n");
+ return -EREMOTEIO;
+ }
+
+ /* Read data from FIFO */
+ for (; len > 0; len--, buf++)
+ *buf = readl(dev->base + RXFIFORDOUT_OFFSET);
+
+ return 0;
+ }
+
+ /* Read any amount of data using the RX FIFO from the i2c bus */
+ static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+ {
+ unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
+ unsigned int last_byte_nak = 0;
+ unsigned int bytes_read = 0;
+ int rc;
+
+ uint8_t *tmp_buf = msg->buf;
+
+ while (bytes_read < msg->len) {
+ if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
+ last_byte_nak = 1; /* NAK last byte of transfer */
+ bytes_to_read = msg->len - bytes_read;
+ }
+
+ rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
+ last_byte_nak);
+ if (rc < 0)
+ return -EREMOTEIO;
+
+ bytes_read += bytes_to_read;
+ tmp_buf += bytes_to_read;
+ }
+
+ return 0;
+ }
+
+ /* Write a single byte of data to the i2c bus */
+ static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
+ unsigned int nak_expected)
+ {
+ int rc;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+ unsigned int nak_received;
+
+ /* Make sure the hardware is ready */
+ rc = bcm_kona_i2c_wait_if_busy(dev);
+ if (rc < 0)
+ return rc;
+
+ /* Clear pending session done interrupt */
+ writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
+
+ /* Unmask the session done interrupt */
+ writel(IER_I2C_INT_EN_MASK, dev->base + IER_OFFSET);
+
+ /* Mark as incomplete before sending the data */
- INIT_COMPLETION(dev->done);
++ reinit_completion(&dev->done);
+
+ /* Send one byte of data */
+ writel(data, dev->base + DAT_OFFSET);
+
+ /* Wait for byte to be written */
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ if (!time_left) {
+ dev_dbg(dev->device, "controller timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
+
+ if (nak_received ^ nak_expected) {
+ dev_dbg(dev->device, "unexpected NAK/ACK\n");
+ return -EREMOTEIO;
+ }
+
+ return 0;
+ }
+
+ /* Write a single TX FIFO worth of data to the i2c bus */
+ static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
+ uint8_t *buf, unsigned int len)
+ {
+ int k;
+ unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT);
+ unsigned int fifo_status;
+
+ /* Mark as incomplete before sending data to the TX FIFO */
++ reinit_completion(&dev->done);
+
+ /* Unmask the fifo empty and nak interrupt */
+ writel(IER_FIFO_INT_EN_MASK | IER_NOACK_EN_MASK,
+ dev->base + IER_OFFSET);
+
+ /* Disable IRQ to load a FIFO worth of data without interruption */
+ disable_irq(dev->irq);
+
+ /* Write data into FIFO */
+ for (k = 0; k < len; k++)
+ writel(buf[k], (dev->base + DAT_OFFSET));
+
+ /* Enable IRQ now that data has been loaded */
+ enable_irq(dev->irq);
+
+ /* Wait for FIFO to empty */
+ do {
+ time_left = wait_for_completion_timeout(&dev->done, time_left);
+ fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
+ } while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ /* Check if there was a NAK */
+ if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
+ dev_err(dev->device, "unexpected NAK\n");
+ return -EREMOTEIO;
+ }
+
+ /* Check if a timeout occured */
+ if (!time_left) {
+ dev_err(dev->device, "completion timed out\n");
+ return -EREMOTEIO;
+ }
+
+ return 0;
+ }
+
+
+ /* Write any amount of data using TX FIFO to the i2c bus */
+ static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+ {
+ unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
+ unsigned int bytes_written = 0;
+ int rc;
+
+ uint8_t *tmp_buf = msg->buf;
+
+ while (bytes_written < msg->len) {
+ if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
+ bytes_to_write = msg->len - bytes_written;
+
+ rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
+ bytes_to_write);
+ if (rc < 0)
+ return -EREMOTEIO;
+
+ bytes_written += bytes_to_write;
+ tmp_buf += bytes_to_write;
+ }
+
+ return 0;
+ }
+
+ /* Send i2c address */
+ static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
+ struct i2c_msg *msg)
+ {
+ unsigned char addr;
+
+ if (msg->flags & I2C_M_TEN) {
+ /* First byte is 11110XX0 where XX is upper 2 bits */
+ addr = 0xF0 | ((msg->addr & 0x300) >> 7);
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+
+ /* Second byte is the remaining 8 bits */
+ addr = msg->addr & 0xFF;
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+
+ if (msg->flags & I2C_M_RD) {
+ /* For read, send restart command */
+ if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
+ return -EREMOTEIO;
+
+ /* Then re-send the first byte with the read bit set */
+ addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+ }
+ } else {
+ addr = msg->addr << 1;
+
+ if (msg->flags & I2C_M_RD)
+ addr |= 1;
+
+ if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+ return -EREMOTEIO;
+ }
+
+ return 0;
+ }
+
+ static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
+ {
+ writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
+ dev->base + CLKEN_OFFSET);
+ }
+
+ static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
+ {
+ writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
+ dev->base + HSTIM_OFFSET);
+
+ writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
+ (dev->std_cfg->time_p << TIM_P_SHIFT) |
+ (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
+ (dev->std_cfg->time_div << TIM_DIV_SHIFT),
+ dev->base + TIM_OFFSET);
+
+ writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
+ (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
+ CLKEN_CLKEN_MASK,
+ dev->base + CLKEN_OFFSET);
+ }
+
+ static void bcm_kona_i2c_config_timing_hs(struct bcm_kona_i2c_dev *dev)
+ {
+ writel((dev->hs_cfg->prescale << TIM_PRESCALE_SHIFT) |
+ (dev->hs_cfg->time_p << TIM_P_SHIFT) |
+ (dev->hs_cfg->no_div << TIM_NO_DIV_SHIFT) |
+ (dev->hs_cfg->time_div << TIM_DIV_SHIFT),
+ dev->base + TIM_OFFSET);
+
+ writel((dev->hs_cfg->hs_hold << HSTIM_HS_HOLD_SHIFT) |
+ (dev->hs_cfg->hs_high_phase << HSTIM_HS_HIGH_PHASE_SHIFT) |
+ (dev->hs_cfg->hs_setup << HSTIM_HS_SETUP_SHIFT),
+ dev->base + HSTIM_OFFSET);
+
+ writel(readl(dev->base + HSTIM_OFFSET) | HSTIM_HS_MODE_MASK,
+ dev->base + HSTIM_OFFSET);
+ }
+
+ static int bcm_kona_i2c_switch_to_hs(struct bcm_kona_i2c_dev *dev)
+ {
+ int rc;
+
+ /* Send mastercode at standard speed */
+ rc = bcm_kona_i2c_write_byte(dev, MASTERCODE, 1);
+ if (rc < 0) {
+ pr_err("High speed handshake failed\n");
+ return rc;
+ }
+
+ /* Configure external clock to higher frequency */
+ rc = clk_set_rate(dev->external_clk, HS_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ /* Reconfigure internal dividers */
+ bcm_kona_i2c_config_timing_hs(dev);
+
+ /* Send a restart command */
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+ if (rc < 0)
+ dev_err(dev->device, "High speed restart command failed\n");
+
+ return rc;
+ }
+
+ static int bcm_kona_i2c_switch_to_std(struct bcm_kona_i2c_dev *dev)
+ {
+ int rc;
+
+ /* Reconfigure internal dividers */
+ bcm_kona_i2c_config_timing(dev);
+
+ /* Configure external clock to lower frequency */
+ rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ }
+
+ return rc;
+ }
+
+ /* Master transfer function */
+ static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter,
+ struct i2c_msg msgs[], int num)
+ {
+ struct bcm_kona_i2c_dev *dev = i2c_get_adapdata(adapter);
+ struct i2c_msg *pmsg;
+ int rc = 0;
+ int i;
+
+ rc = clk_prepare_enable(dev->external_clk);
+ if (rc) {
+ dev_err(dev->device, "%s: peri clock enable failed. err %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ /* Enable pad output */
+ writel(0, dev->base + PADCTL_OFFSET);
+
+ /* Enable internal clocks */
+ bcm_kona_i2c_enable_clock(dev);
+
+ /* Send start command */
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
+ if (rc < 0) {
+ dev_err(dev->device, "Start command failed rc = %d\n", rc);
+ goto xfer_disable_pad;
+ }
+
+ /* Switch to high speed if applicable */
+ if (dev->hs_cfg) {
+ rc = bcm_kona_i2c_switch_to_hs(dev);
+ if (rc < 0)
+ goto xfer_send_stop;
+ }
+
+ /* Loop through all messages */
+ for (i = 0; i < num; i++) {
+ pmsg = &msgs[i];
+
+ /* Send restart for subsequent messages */
+ if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
+ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+ if (rc < 0) {
+ dev_err(dev->device,
+ "restart cmd failed rc = %d\n", rc);
+ goto xfer_send_stop;
+ }
+ }
+
+ /* Send slave address */
+ if (!(pmsg->flags & I2C_M_NOSTART)) {
+ rc = bcm_kona_i2c_do_addr(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device,
+ "NAK from addr %2.2x msg#%d rc = %d\n",
+ pmsg->addr, i, rc);
+ goto xfer_send_stop;
+ }
+ }
+
+ /* Perform data transfer */
+ if (pmsg->flags & I2C_M_RD) {
+ rc = bcm_kona_i2c_read_fifo(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device, "read failure\n");
+ goto xfer_send_stop;
+ }
+ } else {
+ rc = bcm_kona_i2c_write_fifo(dev, pmsg);
+ if (rc < 0) {
+ dev_err(dev->device, "write failure");
+ goto xfer_send_stop;
+ }
+ }
+ }
+
+ rc = num;
+
+ xfer_send_stop:
+ /* Send a STOP command */
+ bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
+
+ /* Return from high speed if applicable */
+ if (dev->hs_cfg) {
+ int hs_rc = bcm_kona_i2c_switch_to_std(dev);
+
+ if (hs_rc)
+ rc = hs_rc;
+ }
+
+ xfer_disable_pad:
+ /* Disable pad output */
+ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+ /* Stop internal clock */
+ bcm_kona_i2c_disable_clock(dev);
+
+ clk_disable_unprepare(dev->external_clk);
+
+ return rc;
+ }
+
+ static uint32_t bcm_kona_i2c_functionality(struct i2c_adapter *adap)
+ {
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
+ I2C_FUNC_NOSTART;
+ }
+
+ static const struct i2c_algorithm bcm_algo = {
+ .master_xfer = bcm_kona_i2c_xfer,
+ .functionality = bcm_kona_i2c_functionality,
+ };
+
+ static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev)
+ {
+ unsigned int bus_speed;
+ int ret = of_property_read_u32(dev->device->of_node, "clock-frequency",
+ &bus_speed);
+ if (ret < 0) {
+ dev_err(dev->device, "missing clock-frequency property\n");
+ return -ENODEV;
+ }
+
+ switch (bus_speed) {
+ case 100000:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+ break;
+ case 400000:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
+ break;
+ case 1000000:
+ dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
+ break;
+ case 3400000:
+ /* Send mastercode at 100k */
+ dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+ dev->hs_cfg = &hs_cfg_table[BCM_SPD_3P4MHZ];
+ break;
+ default:
+ pr_err("%d hz bus speed not supported\n", bus_speed);
+ pr_err("Valid speeds are 100khz, 400khz, 1mhz, and 3.4mhz\n");
+ return -EINVAL;
+ }
+
+ return 0;
+ }
+
+ static int bcm_kona_i2c_probe(struct platform_device *pdev)
+ {
+ int rc = 0;
+ struct bcm_kona_i2c_dev *dev;
+ struct i2c_adapter *adap;
+ struct resource *iomem;
+
+ /* Allocate memory for private data structure */
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, dev);
+ dev->device = &pdev->dev;
+ init_completion(&dev->done);
+
+ /* Map hardware registers */
+ iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dev->base = devm_ioremap_resource(dev->device, iomem);
+ if (IS_ERR(dev->base))
+ return -ENOMEM;
+
+ /* Get and enable external clock */
+ dev->external_clk = devm_clk_get(dev->device, NULL);
+ if (IS_ERR(dev->external_clk)) {
+ dev_err(dev->device, "couldn't get clock\n");
+ return -ENODEV;
+ }
+
+ rc = clk_set_rate(dev->external_clk, STD_EXT_CLK_FREQ);
+ if (rc) {
+ dev_err(dev->device, "%s: clk_set_rate returned %d\n",
+ __func__, rc);
+ return rc;
+ }
+
+ rc = clk_prepare_enable(dev->external_clk);
+ if (rc) {
+ dev_err(dev->device, "couldn't enable clock\n");
+ return rc;
+ }
+
+ /* Parse bus speed */
+ rc = bcm_kona_i2c_assign_bus_speed(dev);
+ if (rc)
+ goto probe_disable_clk;
+
+ /* Enable internal clocks */
+ bcm_kona_i2c_enable_clock(dev);
+
+ /* Configure internal dividers */
+ bcm_kona_i2c_config_timing(dev);
+
+ /* Disable timeout */
+ writel(0, dev->base + TOUT_OFFSET);
+
+ /* Enable autosense */
+ bcm_kona_i2c_enable_autosense(dev);
+
+ /* Enable TX FIFO */
+ writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+ dev->base + TXFCR_OFFSET);
+
+ /* Mask all interrupts */
+ writel(0, dev->base + IER_OFFSET);
+
+ /* Clear all pending interrupts */
+ writel(ISR_CMDBUSY_MASK |
+ ISR_READ_COMPLETE_MASK |
+ ISR_SES_DONE_MASK |
+ ISR_ERR_MASK |
+ ISR_TXFIFOEMPTY_MASK |
+ ISR_NOACK_MASK,
+ dev->base + ISR_OFFSET);
+
+ /* Get the interrupt number */
+ dev->irq = platform_get_irq(pdev, 0);
+ if (dev->irq < 0) {
+ dev_err(dev->device, "no irq resource\n");
+ rc = -ENODEV;
+ goto probe_disable_clk;
+ }
+
+ /* register the ISR handler */
+ rc = devm_request_irq(&pdev->dev, dev->irq, bcm_kona_i2c_isr,
+ IRQF_SHARED, pdev->name, dev);
+ if (rc) {
+ dev_err(dev->device, "failed to request irq %i\n", dev->irq);
+ goto probe_disable_clk;
+ }
+
+ /* Enable the controller but leave it idle */
+ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+ /* Disable pad output */
+ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+ /* Disable internal clock */
+ bcm_kona_i2c_disable_clock(dev);
+
+ /* Disable external clock */
+ clk_disable_unprepare(dev->external_clk);
+
+ /* Add the i2c adapter */
+ adap = &dev->adapter;
+ i2c_set_adapdata(adap, dev);
+ adap->owner = THIS_MODULE;
+ strlcpy(adap->name, "Broadcom I2C adapter", sizeof(adap->name));
+ adap->algo = &bcm_algo;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+
+ rc = i2c_add_adapter(adap);
+ if (rc) {
+ dev_err(dev->device, "failed to add adapter\n");
+ return rc;
+ }
+
+ dev_info(dev->device, "device registered successfully\n");
+
+ return 0;
+
+ probe_disable_clk:
+ bcm_kona_i2c_disable_clock(dev);
+ clk_disable_unprepare(dev->external_clk);
+
+ return rc;
+ }
+
+ static int bcm_kona_i2c_remove(struct platform_device *pdev)
+ {
+ struct bcm_kona_i2c_dev *dev = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&dev->adapter);
+
+ return 0;
+ }
+
+ static const struct of_device_id bcm_kona_i2c_of_match[] = {
+ {.compatible = "brcm,kona-i2c",},
+ {},
+ };
+ MODULE_DEVICE_TABLE(of, kona_i2c_of_match);
+
+ static struct platform_driver bcm_kona_i2c_driver = {
+ .driver = {
+ .name = "bcm-kona-i2c",
+ .owner = THIS_MODULE,
+ .of_match_table = bcm_kona_i2c_of_match,
+ },
+ .probe = bcm_kona_i2c_probe,
+ .remove = bcm_kona_i2c_remove,
+ };
+ module_platform_driver(bcm_kona_i2c_driver);
+
+ MODULE_AUTHOR("Tim Kryger <tkryger@broadcom.com>");
+ MODULE_DESCRIPTION("Broadcom Kona I2C Driver");
+ MODULE_LICENSE("GPL v2");
--- /dev/null
- INIT_COMPLETION(i2c->msg_complete);
+ /**
+ * i2c-exynos5.c - Samsung Exynos5 I2C Controller Driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+ #include <linux/kernel.h>
+ #include <linux/module.h>
+
+ #include <linux/i2c.h>
+ #include <linux/init.h>
+ #include <linux/time.h>
+ #include <linux/interrupt.h>
+ #include <linux/delay.h>
+ #include <linux/errno.h>
+ #include <linux/err.h>
+ #include <linux/platform_device.h>
+ #include <linux/clk.h>
+ #include <linux/slab.h>
+ #include <linux/io.h>
+ #include <linux/of_address.h>
+ #include <linux/of_irq.h>
+ #include <linux/spinlock.h>
+
+ /*
+ * HSI2C controller from Samsung supports 2 modes of operation
+ * 1. Auto mode: Where in master automatically controls the whole transaction
+ * 2. Manual mode: Software controls the transaction by issuing commands
+ * START, READ, WRITE, STOP, RESTART in I2C_MANUAL_CMD register.
+ *
+ * Operation mode can be selected by setting AUTO_MODE bit in I2C_CONF register
+ *
+ * Special bits are available for both modes of operation to set commands
+ * and for checking transfer status
+ */
+
+ /* Register Map */
+ #define HSI2C_CTL 0x00
+ #define HSI2C_FIFO_CTL 0x04
+ #define HSI2C_TRAILIG_CTL 0x08
+ #define HSI2C_CLK_CTL 0x0C
+ #define HSI2C_CLK_SLOT 0x10
+ #define HSI2C_INT_ENABLE 0x20
+ #define HSI2C_INT_STATUS 0x24
+ #define HSI2C_ERR_STATUS 0x2C
+ #define HSI2C_FIFO_STATUS 0x30
+ #define HSI2C_TX_DATA 0x34
+ #define HSI2C_RX_DATA 0x38
+ #define HSI2C_CONF 0x40
+ #define HSI2C_AUTO_CONF 0x44
+ #define HSI2C_TIMEOUT 0x48
+ #define HSI2C_MANUAL_CMD 0x4C
+ #define HSI2C_TRANS_STATUS 0x50
+ #define HSI2C_TIMING_HS1 0x54
+ #define HSI2C_TIMING_HS2 0x58
+ #define HSI2C_TIMING_HS3 0x5C
+ #define HSI2C_TIMING_FS1 0x60
+ #define HSI2C_TIMING_FS2 0x64
+ #define HSI2C_TIMING_FS3 0x68
+ #define HSI2C_TIMING_SLA 0x6C
+ #define HSI2C_ADDR 0x70
+
+ /* I2C_CTL Register bits */
+ #define HSI2C_FUNC_MODE_I2C (1u << 0)
+ #define HSI2C_MASTER (1u << 3)
+ #define HSI2C_RXCHON (1u << 6)
+ #define HSI2C_TXCHON (1u << 7)
+ #define HSI2C_SW_RST (1u << 31)
+
+ /* I2C_FIFO_CTL Register bits */
+ #define HSI2C_RXFIFO_EN (1u << 0)
+ #define HSI2C_TXFIFO_EN (1u << 1)
+ #define HSI2C_RXFIFO_TRIGGER_LEVEL(x) ((x) << 4)
+ #define HSI2C_TXFIFO_TRIGGER_LEVEL(x) ((x) << 16)
+
+ /* As per user manual FIFO max depth is 64bytes */
+ #define HSI2C_FIFO_MAX 0x40
+ /* default trigger levels for Tx and Rx FIFOs */
+ #define HSI2C_DEF_TXFIFO_LVL (HSI2C_FIFO_MAX - 0x30)
+ #define HSI2C_DEF_RXFIFO_LVL (HSI2C_FIFO_MAX - 0x10)
+
+ /* I2C_TRAILING_CTL Register bits */
+ #define HSI2C_TRAILING_COUNT (0xf)
+
+ /* I2C_INT_EN Register bits */
+ #define HSI2C_INT_TX_ALMOSTEMPTY_EN (1u << 0)
+ #define HSI2C_INT_RX_ALMOSTFULL_EN (1u << 1)
+ #define HSI2C_INT_TRAILING_EN (1u << 6)
+ #define HSI2C_INT_I2C_EN (1u << 9)
+
+ /* I2C_INT_STAT Register bits */
+ #define HSI2C_INT_TX_ALMOSTEMPTY (1u << 0)
+ #define HSI2C_INT_RX_ALMOSTFULL (1u << 1)
+ #define HSI2C_INT_TX_UNDERRUN (1u << 2)
+ #define HSI2C_INT_TX_OVERRUN (1u << 3)
+ #define HSI2C_INT_RX_UNDERRUN (1u << 4)
+ #define HSI2C_INT_RX_OVERRUN (1u << 5)
+ #define HSI2C_INT_TRAILING (1u << 6)
+ #define HSI2C_INT_I2C (1u << 9)
+
+ /* I2C_FIFO_STAT Register bits */
+ #define HSI2C_RX_FIFO_EMPTY (1u << 24)
+ #define HSI2C_RX_FIFO_FULL (1u << 23)
+ #define HSI2C_RX_FIFO_LVL(x) ((x >> 16) & 0x7f)
+ #define HSI2C_TX_FIFO_EMPTY (1u << 8)
+ #define HSI2C_TX_FIFO_FULL (1u << 7)
+ #define HSI2C_TX_FIFO_LVL(x) ((x >> 0) & 0x7f)
+
+ /* I2C_CONF Register bits */
+ #define HSI2C_AUTO_MODE (1u << 31)
+ #define HSI2C_10BIT_ADDR_MODE (1u << 30)
+ #define HSI2C_HS_MODE (1u << 29)
+
+ /* I2C_AUTO_CONF Register bits */
+ #define HSI2C_READ_WRITE (1u << 16)
+ #define HSI2C_STOP_AFTER_TRANS (1u << 17)
+ #define HSI2C_MASTER_RUN (1u << 31)
+
+ /* I2C_TIMEOUT Register bits */
+ #define HSI2C_TIMEOUT_EN (1u << 31)
+ #define HSI2C_TIMEOUT_MASK 0xff
+
+ /* I2C_TRANS_STATUS register bits */
+ #define HSI2C_MASTER_BUSY (1u << 17)
+ #define HSI2C_SLAVE_BUSY (1u << 16)
+ #define HSI2C_TIMEOUT_AUTO (1u << 4)
+ #define HSI2C_NO_DEV (1u << 3)
+ #define HSI2C_NO_DEV_ACK (1u << 2)
+ #define HSI2C_TRANS_ABORT (1u << 1)
+ #define HSI2C_TRANS_DONE (1u << 0)
+
+ /* I2C_ADDR register bits */
+ #define HSI2C_SLV_ADDR_SLV(x) ((x & 0x3ff) << 0)
+ #define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10)
+ #define HSI2C_MASTER_ID(x) ((x & 0xff) << 24)
+ #define MASTER_ID(x) ((x & 0x7) + 0x08)
+
+ /*
+ * Controller operating frequency, timing values for operation
+ * are calculated against this frequency
+ */
+ #define HSI2C_HS_TX_CLOCK 1000000
+ #define HSI2C_FS_TX_CLOCK 100000
+ #define HSI2C_HIGH_SPD 1
+ #define HSI2C_FAST_SPD 0
+
+ #define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
+
+ struct exynos5_i2c {
+ struct i2c_adapter adap;
+ unsigned int suspended:1;
+
+ struct i2c_msg *msg;
+ struct completion msg_complete;
+ unsigned int msg_ptr;
+
+ unsigned int irq;
+
+ void __iomem *regs;
+ struct clk *clk;
+ struct device *dev;
+ int state;
+
+ spinlock_t lock; /* IRQ synchronization */
+
+ /*
+ * Since the TRANS_DONE bit is cleared on read, and we may read it
+ * either during an IRQ or after a transaction, keep track of its
+ * state here.
+ */
+ int trans_done;
+
+ /* Controller operating frequency */
+ unsigned int fs_clock;
+ unsigned int hs_clock;
+
+ /*
+ * HSI2C Controller can operate in
+ * 1. High speed upto 3.4Mbps
+ * 2. Fast speed upto 1Mbps
+ */
+ int speed_mode;
+ };
+
+ static const struct of_device_id exynos5_i2c_match[] = {
+ { .compatible = "samsung,exynos5-hsi2c" },
+ {},
+ };
+ MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
+
+ static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
+ {
+ writel(readl(i2c->regs + HSI2C_INT_STATUS),
+ i2c->regs + HSI2C_INT_STATUS);
+ }
+
+ /*
+ * exynos5_i2c_set_timing: updates the registers with appropriate
+ * timing values calculated
+ *
+ * Returns 0 on success, -EINVAL if the cycle length cannot
+ * be calculated.
+ */
+ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
+ {
+ u32 i2c_timing_s1;
+ u32 i2c_timing_s2;
+ u32 i2c_timing_s3;
+ u32 i2c_timing_sla;
+ unsigned int t_start_su, t_start_hd;
+ unsigned int t_stop_su;
+ unsigned int t_data_su, t_data_hd;
+ unsigned int t_scl_l, t_scl_h;
+ unsigned int t_sr_release;
+ unsigned int t_ftl_cycle;
+ unsigned int clkin = clk_get_rate(i2c->clk);
+ unsigned int div, utemp0 = 0, utemp1 = 0, clk_cycle;
+ unsigned int op_clk = (mode == HSI2C_HIGH_SPD) ?
+ i2c->hs_clock : i2c->fs_clock;
+
+ /*
+ * FPCLK / FI2C =
+ * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
+ * utemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
+ * utemp1 = (TSCLK_L + TSCLK_H + 2)
+ */
+ t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7;
+ utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle;
+
+ /* CLK_DIV max is 256 */
+ for (div = 0; div < 256; div++) {
+ utemp1 = utemp0 / (div + 1);
+
+ /*
+ * SCL_L and SCL_H each has max value of 255
+ * Hence, For the clk_cycle to the have right value
+ * utemp1 has to be less then 512 and more than 4.
+ */
+ if ((utemp1 < 512) && (utemp1 > 4)) {
+ clk_cycle = utemp1 - 2;
+ break;
+ } else if (div == 255) {
+ dev_warn(i2c->dev, "Failed to calculate divisor");
+ return -EINVAL;
+ }
+ }
+
+ t_scl_l = clk_cycle / 2;
+ t_scl_h = clk_cycle / 2;
+ t_start_su = t_scl_l;
+ t_start_hd = t_scl_l;
+ t_stop_su = t_scl_l;
+ t_data_su = t_scl_l / 2;
+ t_data_hd = t_scl_l / 2;
+ t_sr_release = clk_cycle;
+
+ i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
+ i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
+ i2c_timing_s3 = div << 16 | t_sr_release << 0;
+ i2c_timing_sla = t_data_hd << 0;
+
+ dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n",
+ t_start_su, t_start_hd, t_stop_su);
+ dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n",
+ t_data_su, t_scl_l, t_scl_h);
+ dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n",
+ div, t_sr_release);
+ dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
+
+ if (mode == HSI2C_HIGH_SPD) {
+ writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1);
+ writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2);
+ writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
+ } else {
+ writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1);
+ writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2);
+ writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3);
+ }
+ writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA);
+
+ return 0;
+ }
+
+ static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c)
+ {
+ /*
+ * Configure the Fast speed timing values
+ * Even the High Speed mode initially starts with Fast mode
+ */
+ if (exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD)) {
+ dev_err(i2c->dev, "HSI2C FS Clock set up failed\n");
+ return -EINVAL;
+ }
+
+ /* configure the High speed timing values */
+ if (i2c->speed_mode == HSI2C_HIGH_SPD) {
+ if (exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD)) {
+ dev_err(i2c->dev, "HSI2C HS Clock set up failed\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+ }
+
+ /*
+ * exynos5_i2c_init: configures the controller for I2C functionality
+ * Programs I2C controller for Master mode operation
+ */
+ static void exynos5_i2c_init(struct exynos5_i2c *i2c)
+ {
+ u32 i2c_conf = readl(i2c->regs + HSI2C_CONF);
+ u32 i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT);
+
+ /* Clear to disable Timeout */
+ i2c_timeout &= ~HSI2C_TIMEOUT_EN;
+ writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT);
+
+ writel((HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
+ i2c->regs + HSI2C_CTL);
+ writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL);
+
+ if (i2c->speed_mode == HSI2C_HIGH_SPD) {
+ writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)),
+ i2c->regs + HSI2C_ADDR);
+ i2c_conf |= HSI2C_HS_MODE;
+ }
+
+ writel(i2c_conf | HSI2C_AUTO_MODE, i2c->regs + HSI2C_CONF);
+ }
+
+ static void exynos5_i2c_reset(struct exynos5_i2c *i2c)
+ {
+ u32 i2c_ctl;
+
+ /* Set and clear the bit for reset */
+ i2c_ctl = readl(i2c->regs + HSI2C_CTL);
+ i2c_ctl |= HSI2C_SW_RST;
+ writel(i2c_ctl, i2c->regs + HSI2C_CTL);
+
+ i2c_ctl = readl(i2c->regs + HSI2C_CTL);
+ i2c_ctl &= ~HSI2C_SW_RST;
+ writel(i2c_ctl, i2c->regs + HSI2C_CTL);
+
+ /* We don't expect calculations to fail during the run */
+ exynos5_hsi2c_clock_setup(i2c);
+ /* Initialize the configure registers */
+ exynos5_i2c_init(i2c);
+ }
+
+ /*
+ * exynos5_i2c_irq: top level IRQ servicing routine
+ *
+ * INT_STATUS registers gives the interrupt details. Further,
+ * FIFO_STATUS or TRANS_STATUS registers are to be check for detailed
+ * state of the bus.
+ */
+ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
+ {
+ struct exynos5_i2c *i2c = dev_id;
+ u32 fifo_level, int_status, fifo_status, trans_status;
+ unsigned char byte;
+ int len = 0;
+
+ i2c->state = -EINVAL;
+
+ spin_lock(&i2c->lock);
+
+ int_status = readl(i2c->regs + HSI2C_INT_STATUS);
+ writel(int_status, i2c->regs + HSI2C_INT_STATUS);
+ fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
+
+ /* handle interrupt related to the transfer status */
+ if (int_status & HSI2C_INT_I2C) {
+ trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
+ if (trans_status & HSI2C_NO_DEV_ACK) {
+ dev_dbg(i2c->dev, "No ACK from device\n");
+ i2c->state = -ENXIO;
+ goto stop;
+ } else if (trans_status & HSI2C_NO_DEV) {
+ dev_dbg(i2c->dev, "No device\n");
+ i2c->state = -ENXIO;
+ goto stop;
+ } else if (trans_status & HSI2C_TRANS_ABORT) {
+ dev_dbg(i2c->dev, "Deal with arbitration lose\n");
+ i2c->state = -EAGAIN;
+ goto stop;
+ } else if (trans_status & HSI2C_TIMEOUT_AUTO) {
+ dev_dbg(i2c->dev, "Accessing device timed out\n");
+ i2c->state = -EAGAIN;
+ goto stop;
+ } else if (trans_status & HSI2C_TRANS_DONE) {
+ i2c->trans_done = 1;
+ i2c->state = 0;
+ }
+ }
+
+ if ((i2c->msg->flags & I2C_M_RD) && (int_status &
+ (HSI2C_INT_TRAILING | HSI2C_INT_RX_ALMOSTFULL))) {
+ fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
+ fifo_level = HSI2C_RX_FIFO_LVL(fifo_status);
+ len = min(fifo_level, i2c->msg->len - i2c->msg_ptr);
+
+ while (len > 0) {
+ byte = (unsigned char)
+ readl(i2c->regs + HSI2C_RX_DATA);
+ i2c->msg->buf[i2c->msg_ptr++] = byte;
+ len--;
+ }
+ i2c->state = 0;
+ } else if (int_status & HSI2C_INT_TX_ALMOSTEMPTY) {
+ fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
+ fifo_level = HSI2C_TX_FIFO_LVL(fifo_status);
+
+ len = HSI2C_FIFO_MAX - fifo_level;
+ if (len > (i2c->msg->len - i2c->msg_ptr))
+ len = i2c->msg->len - i2c->msg_ptr;
+
+ while (len > 0) {
+ byte = i2c->msg->buf[i2c->msg_ptr++];
+ writel(byte, i2c->regs + HSI2C_TX_DATA);
+ len--;
+ }
+ i2c->state = 0;
+ }
+
+ stop:
+ if ((i2c->trans_done && (i2c->msg->len == i2c->msg_ptr)) ||
+ (i2c->state < 0)) {
+ writel(0, i2c->regs + HSI2C_INT_ENABLE);
+ exynos5_i2c_clr_pend_irq(i2c);
+ complete(&i2c->msg_complete);
+ }
+
+ spin_unlock(&i2c->lock);
+
+ return IRQ_HANDLED;
+ }
+
+ /*
+ * exynos5_i2c_wait_bus_idle
+ *
+ * Wait for the bus to go idle, indicated by the MASTER_BUSY bit being
+ * cleared.
+ *
+ * Returns -EBUSY if the bus cannot be bought to idle
+ */
+ static int exynos5_i2c_wait_bus_idle(struct exynos5_i2c *i2c)
+ {
+ unsigned long stop_time;
+ u32 trans_status;
+
+ /* wait for 100 milli seconds for the bus to be idle */
+ stop_time = jiffies + msecs_to_jiffies(100) + 1;
+ do {
+ trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
+ if (!(trans_status & HSI2C_MASTER_BUSY))
+ return 0;
+
+ usleep_range(50, 200);
+ } while (time_before(jiffies, stop_time));
+
+ return -EBUSY;
+ }
+
+ /*
+ * exynos5_i2c_message_start: Configures the bus and starts the xfer
+ * i2c: struct exynos5_i2c pointer for the current bus
+ * stop: Enables stop after transfer if set. Set for last transfer of
+ * in the list of messages.
+ *
+ * Configures the bus for read/write function
+ * Sets chip address to talk to, message length to be sent.
+ * Enables appropriate interrupts and sends start xfer command.
+ */
+ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
+ {
+ u32 i2c_ctl;
+ u32 int_en = HSI2C_INT_I2C_EN;
+ u32 i2c_auto_conf = 0;
+ u32 fifo_ctl;
+ unsigned long flags;
+
+ i2c_ctl = readl(i2c->regs + HSI2C_CTL);
+ i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
+ fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN;
+
+ if (i2c->msg->flags & I2C_M_RD) {
+ i2c_ctl |= HSI2C_RXCHON;
+
+ i2c_auto_conf = HSI2C_READ_WRITE;
+
+ fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(HSI2C_DEF_TXFIFO_LVL);
+ int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
+ HSI2C_INT_TRAILING_EN);
+ } else {
+ i2c_ctl |= HSI2C_TXCHON;
+
+ fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(HSI2C_DEF_RXFIFO_LVL);
+ int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
+ }
+
+ writel(HSI2C_SLV_ADDR_MAS(i2c->msg->addr), i2c->regs + HSI2C_ADDR);
+
+ writel(fifo_ctl, i2c->regs + HSI2C_FIFO_CTL);
+ writel(i2c_ctl, i2c->regs + HSI2C_CTL);
+
+
+ /*
+ * Enable interrupts before starting the transfer so that we don't
+ * miss any INT_I2C interrupts.
+ */
+ spin_lock_irqsave(&i2c->lock, flags);
+ writel(int_en, i2c->regs + HSI2C_INT_ENABLE);
+
+ if (stop == 1)
+ i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS;
+ i2c_auto_conf |= i2c->msg->len;
+ i2c_auto_conf |= HSI2C_MASTER_RUN;
+ writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
+ spin_unlock_irqrestore(&i2c->lock, flags);
+ }
+
+ static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
+ struct i2c_msg *msgs, int stop)
+ {
+ unsigned long timeout;
+ int ret;
+
+ i2c->msg = msgs;
+ i2c->msg_ptr = 0;
+ i2c->trans_done = 0;
+
++ reinit_completion(&i2c->msg_complete);
+
+ exynos5_i2c_message_start(i2c, stop);
+
+ timeout = wait_for_completion_timeout(&i2c->msg_complete,
+ EXYNOS5_I2C_TIMEOUT);
+ if (timeout == 0)
+ ret = -ETIMEDOUT;
+ else
+ ret = i2c->state;
+
+ /*
+ * If this is the last message to be transfered (stop == 1)
+ * Then check if the bus can be brought back to idle.
+ */
+ if (ret == 0 && stop)
+ ret = exynos5_i2c_wait_bus_idle(i2c);
+
+ if (ret < 0) {
+ exynos5_i2c_reset(i2c);
+ if (ret == -ETIMEDOUT)
+ dev_warn(i2c->dev, "%s timeout\n",
+ (msgs->flags & I2C_M_RD) ? "rx" : "tx");
+ }
+
+ /* Return the state as in interrupt routine */
+ return ret;
+ }
+
+ static int exynos5_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+ {
+ struct exynos5_i2c *i2c = (struct exynos5_i2c *)adap->algo_data;
+ int i = 0, ret = 0, stop = 0;
+
+ if (i2c->suspended) {
+ dev_err(i2c->dev, "HS-I2C is not initialzed.\n");
+ return -EIO;
+ }
+
+ clk_prepare_enable(i2c->clk);
+
+ for (i = 0; i < num; i++, msgs++) {
+ stop = (i == num - 1);
+
+ ret = exynos5_i2c_xfer_msg(i2c, msgs, stop);
+
+ if (ret < 0)
+ goto out;
+ }
+
+ if (i == num) {
+ ret = num;
+ } else {
+ /* Only one message, cannot access the device */
+ if (i == 1)
+ ret = -EREMOTEIO;
+ else
+ ret = i;
+
+ dev_warn(i2c->dev, "xfer message failed\n");
+ }
+
+ out:
+ clk_disable_unprepare(i2c->clk);
+ return ret;
+ }
+
+ static u32 exynos5_i2c_func(struct i2c_adapter *adap)
+ {
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+ }
+
+ static const struct i2c_algorithm exynos5_i2c_algorithm = {
+ .master_xfer = exynos5_i2c_xfer,
+ .functionality = exynos5_i2c_func,
+ };
+
+ static int exynos5_i2c_probe(struct platform_device *pdev)
+ {
+ struct device_node *np = pdev->dev.of_node;
+ struct exynos5_i2c *i2c;
+ struct resource *mem;
+ unsigned int op_clock;
+ int ret;
+
+ i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
+ if (!i2c) {
+ dev_err(&pdev->dev, "no memory for state\n");
+ return -ENOMEM;
+ }
+
+ if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
+ i2c->speed_mode = HSI2C_FAST_SPD;
+ i2c->fs_clock = HSI2C_FS_TX_CLOCK;
+ } else {
+ if (op_clock >= HSI2C_HS_TX_CLOCK) {
+ i2c->speed_mode = HSI2C_HIGH_SPD;
+ i2c->fs_clock = HSI2C_FS_TX_CLOCK;
+ i2c->hs_clock = op_clock;
+ } else {
+ i2c->speed_mode = HSI2C_FAST_SPD;
+ i2c->fs_clock = op_clock;
+ }
+ }
+
+ strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name));
+ i2c->adap.owner = THIS_MODULE;
+ i2c->adap.algo = &exynos5_i2c_algorithm;
+ i2c->adap.retries = 3;
+
+ i2c->dev = &pdev->dev;
+ i2c->clk = devm_clk_get(&pdev->dev, "hsi2c");
+ if (IS_ERR(i2c->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ return -ENOENT;
+ }
+
+ clk_prepare_enable(i2c->clk);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ i2c->regs = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(i2c->regs)) {
+ ret = PTR_ERR(i2c->regs);
+ goto err_clk;
+ }
+
+ i2c->adap.dev.of_node = np;
+ i2c->adap.algo_data = i2c;
+ i2c->adap.dev.parent = &pdev->dev;
+
+ /* Clear pending interrupts from u-boot or misc causes */
+ exynos5_i2c_clr_pend_irq(i2c);
+
+ spin_lock_init(&i2c->lock);
+ init_completion(&i2c->msg_complete);
+
+ i2c->irq = ret = platform_get_irq(pdev, 0);
+ if (ret <= 0) {
+ dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n");
+ ret = -EINVAL;
+ goto err_clk;
+ }
+
+ ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq,
+ IRQF_NO_SUSPEND | IRQF_ONESHOT,
+ dev_name(&pdev->dev), i2c);
+
+ if (ret != 0) {
+ dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq);
+ goto err_clk;
+ }
+
+ ret = exynos5_hsi2c_clock_setup(i2c);
+ if (ret)
+ goto err_clk;
+
+ exynos5_i2c_init(i2c);
+
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+ goto err_clk;
+ }
+
+ platform_set_drvdata(pdev, i2c);
+
+ err_clk:
+ clk_disable_unprepare(i2c->clk);
+ return ret;
+ }
+
+ static int exynos5_i2c_remove(struct platform_device *pdev)
+ {
+ struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c->adap);
+
+ return 0;
+ }
+
+ static int exynos5_i2c_suspend_noirq(struct device *dev)
+ {
+ struct platform_device *pdev = to_platform_device(dev);
+ struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c->suspended = 1;
+
+ return 0;
+ }
+
+ static int exynos5_i2c_resume_noirq(struct device *dev)
+ {
+ struct platform_device *pdev = to_platform_device(dev);
+ struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
+ int ret = 0;
+
+ clk_prepare_enable(i2c->clk);
+
+ ret = exynos5_hsi2c_clock_setup(i2c);
+ if (ret) {
+ clk_disable_unprepare(i2c->clk);
+ return ret;
+ }
+
+ exynos5_i2c_init(i2c);
+ clk_disable_unprepare(i2c->clk);
+ i2c->suspended = 0;
+
+ return 0;
+ }
+
+ static SIMPLE_DEV_PM_OPS(exynos5_i2c_dev_pm_ops, exynos5_i2c_suspend_noirq,
+ exynos5_i2c_resume_noirq);
+
+ static struct platform_driver exynos5_i2c_driver = {
+ .probe = exynos5_i2c_probe,
+ .remove = exynos5_i2c_remove,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "exynos5-hsi2c",
+ .pm = &exynos5_i2c_dev_pm_ops,
+ .of_match_table = exynos5_i2c_match,
+ },
+ };
+
+ module_platform_driver(exynos5_i2c_driver);
+
+ MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver");
+ MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@samsung.com>");
+ MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>");
+ MODULE_LICENSE("GPL v2");
return -EINVAL;
/*
- * The current boundary to select between PIO/DMA transfer method
- * is set to 8 bytes, transfers shorter than 8 bytes are transfered
- * using PIO mode while longer transfers use DMA. The 8 byte border is
- * based on this empirical measurement and a lot of previous frobbing.
+ * The MX28 I2C IP block can only do PIO READ for transfer of to up
+ * 4 bytes of length. The write transfer is not limited as it can use
+ * clock stretching to avoid FIFO underruns.
*/
+ if ((msg->flags & I2C_M_RD) && (msg->len <= 4))
+ use_pio = 1;
+ if (!(msg->flags & I2C_M_RD) && (msg->len < 7))
+ use_pio = 1;
+
i2c->cmd_err = 0;
- if (0) { /* disable PIO mode until a proper fix is made */
+ if (use_pio) {
ret = mxs_i2c_pio_setup_xfer(adap, msg, flags);
- if (ret) {
- err = mxs_i2c_reset(i2c);
- if (err)
- return err;
- }
+ /* No need to reset the block if NAK was received. */
+ if (ret && (ret != -ENXIO))
+ mxs_i2c_reset(i2c);
} else {
- INIT_COMPLETION(i2c->cmd_complete);
+ reinit_completion(&i2c->cmd_complete);
ret = mxs_i2c_dma_setup_xfer(adap, msg, flags);
if (ret)
return ret;
--- /dev/null
- INIT_COMPLETION(i2c_dev->complete);
+ /*
+ * Copyright (C) 2013 STMicroelectronics
+ *
+ * I2C master mode controller driver, used in STMicroelectronics devices.
+ *
+ * Author: Maxime Coquelin <maxime.coquelin@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ */
+
+ #include <linux/module.h>
+ #include <linux/platform_device.h>
+ #include <linux/i2c.h>
+ #include <linux/clk.h>
+ #include <linux/io.h>
+ #include <linux/delay.h>
+ #include <linux/interrupt.h>
+ #include <linux/err.h>
+ #include <linux/of.h>
+ #include <linux/of_address.h>
+ #include <linux/of_irq.h>
+
+ /* SSC registers */
+ #define SSC_BRG 0x000
+ #define SSC_TBUF 0x004
+ #define SSC_RBUF 0x008
+ #define SSC_CTL 0x00C
+ #define SSC_IEN 0x010
+ #define SSC_STA 0x014
+ #define SSC_I2C 0x018
+ #define SSC_SLAD 0x01C
+ #define SSC_REP_START_HOLD 0x020
+ #define SSC_START_HOLD 0x024
+ #define SSC_REP_START_SETUP 0x028
+ #define SSC_DATA_SETUP 0x02C
+ #define SSC_STOP_SETUP 0x030
+ #define SSC_BUS_FREE 0x034
+ #define SSC_TX_FSTAT 0x038
+ #define SSC_RX_FSTAT 0x03C
+ #define SSC_PRE_SCALER_BRG 0x040
+ #define SSC_CLR 0x080
+ #define SSC_NOISE_SUPP_WIDTH 0x100
+ #define SSC_PRSCALER 0x104
+ #define SSC_NOISE_SUPP_WIDTH_DATAOUT 0x108
+ #define SSC_PRSCALER_DATAOUT 0x10c
+
+ /* SSC Control */
+ #define SSC_CTL_DATA_WIDTH_9 0x8
+ #define SSC_CTL_DATA_WIDTH_MSK 0xf
+ #define SSC_CTL_BM 0xf
+ #define SSC_CTL_HB BIT(4)
+ #define SSC_CTL_PH BIT(5)
+ #define SSC_CTL_PO BIT(6)
+ #define SSC_CTL_SR BIT(7)
+ #define SSC_CTL_MS BIT(8)
+ #define SSC_CTL_EN BIT(9)
+ #define SSC_CTL_LPB BIT(10)
+ #define SSC_CTL_EN_TX_FIFO BIT(11)
+ #define SSC_CTL_EN_RX_FIFO BIT(12)
+ #define SSC_CTL_EN_CLST_RX BIT(13)
+
+ /* SSC Interrupt Enable */
+ #define SSC_IEN_RIEN BIT(0)
+ #define SSC_IEN_TIEN BIT(1)
+ #define SSC_IEN_TEEN BIT(2)
+ #define SSC_IEN_REEN BIT(3)
+ #define SSC_IEN_PEEN BIT(4)
+ #define SSC_IEN_AASEN BIT(6)
+ #define SSC_IEN_STOPEN BIT(7)
+ #define SSC_IEN_ARBLEN BIT(8)
+ #define SSC_IEN_NACKEN BIT(10)
+ #define SSC_IEN_REPSTRTEN BIT(11)
+ #define SSC_IEN_TX_FIFO_HALF BIT(12)
+ #define SSC_IEN_RX_FIFO_HALF_FULL BIT(14)
+
+ /* SSC Status */
+ #define SSC_STA_RIR BIT(0)
+ #define SSC_STA_TIR BIT(1)
+ #define SSC_STA_TE BIT(2)
+ #define SSC_STA_RE BIT(3)
+ #define SSC_STA_PE BIT(4)
+ #define SSC_STA_CLST BIT(5)
+ #define SSC_STA_AAS BIT(6)
+ #define SSC_STA_STOP BIT(7)
+ #define SSC_STA_ARBL BIT(8)
+ #define SSC_STA_BUSY BIT(9)
+ #define SSC_STA_NACK BIT(10)
+ #define SSC_STA_REPSTRT BIT(11)
+ #define SSC_STA_TX_FIFO_HALF BIT(12)
+ #define SSC_STA_TX_FIFO_FULL BIT(13)
+ #define SSC_STA_RX_FIFO_HALF BIT(14)
+
+ /* SSC I2C Control */
+ #define SSC_I2C_I2CM BIT(0)
+ #define SSC_I2C_STRTG BIT(1)
+ #define SSC_I2C_STOPG BIT(2)
+ #define SSC_I2C_ACKG BIT(3)
+ #define SSC_I2C_AD10 BIT(4)
+ #define SSC_I2C_TXENB BIT(5)
+ #define SSC_I2C_REPSTRTG BIT(11)
+ #define SSC_I2C_SLAVE_DISABLE BIT(12)
+
+ /* SSC Tx FIFO Status */
+ #define SSC_TX_FSTAT_STATUS 0x07
+
+ /* SSC Rx FIFO Status */
+ #define SSC_RX_FSTAT_STATUS 0x07
+
+ /* SSC Clear bit operation */
+ #define SSC_CLR_SSCAAS BIT(6)
+ #define SSC_CLR_SSCSTOP BIT(7)
+ #define SSC_CLR_SSCARBL BIT(8)
+ #define SSC_CLR_NACK BIT(10)
+ #define SSC_CLR_REPSTRT BIT(11)
+
+ /* SSC Clock Prescaler */
+ #define SSC_PRSC_VALUE 0x0f
+
+
+ #define SSC_TXFIFO_SIZE 0x8
+ #define SSC_RXFIFO_SIZE 0x8
+
+ enum st_i2c_mode {
+ I2C_MODE_STANDARD,
+ I2C_MODE_FAST,
+ I2C_MODE_END,
+ };
+
+ /**
+ * struct st_i2c_timings - per-Mode tuning parameters
+ * @rate: I2C bus rate
+ * @rep_start_hold: I2C repeated start hold time requirement
+ * @rep_start_setup: I2C repeated start set up time requirement
+ * @start_hold: I2C start hold time requirement
+ * @data_setup_time: I2C data set up time requirement
+ * @stop_setup_time: I2C stop set up time requirement
+ * @bus_free_time: I2C bus free time requirement
+ * @sda_pulse_min_limit: I2C SDA pulse mini width limit
+ */
+ struct st_i2c_timings {
+ u32 rate;
+ u32 rep_start_hold;
+ u32 rep_start_setup;
+ u32 start_hold;
+ u32 data_setup_time;
+ u32 stop_setup_time;
+ u32 bus_free_time;
+ u32 sda_pulse_min_limit;
+ };
+
+ /**
+ * struct st_i2c_client - client specific data
+ * @addr: 8-bit slave addr, including r/w bit
+ * @count: number of bytes to be transfered
+ * @xfered: number of bytes already transferred
+ * @buf: data buffer
+ * @result: result of the transfer
+ * @stop: last I2C msg to be sent, i.e. STOP to be generated
+ */
+ struct st_i2c_client {
+ u8 addr;
+ u32 count;
+ u32 xfered;
+ u8 *buf;
+ int result;
+ bool stop;
+ };
+
+ /**
+ * struct st_i2c_dev - private data of the controller
+ * @adap: I2C adapter for this controller
+ * @dev: device for this controller
+ * @base: virtual memory area
+ * @complete: completion of I2C message
+ * @irq: interrupt line for th controller
+ * @clk: hw ssc block clock
+ * @mode: I2C mode of the controller. Standard or Fast only supported
+ * @scl_min_width_us: SCL line minimum pulse width in us
+ * @sda_min_width_us: SDA line minimum pulse width in us
+ * @client: I2C transfert information
+ * @busy: I2C transfer on-going
+ */
+ struct st_i2c_dev {
+ struct i2c_adapter adap;
+ struct device *dev;
+ void __iomem *base;
+ struct completion complete;
+ int irq;
+ struct clk *clk;
+ int mode;
+ u32 scl_min_width_us;
+ u32 sda_min_width_us;
+ struct st_i2c_client client;
+ bool busy;
+ };
+
+ static inline void st_i2c_set_bits(void __iomem *reg, u32 mask)
+ {
+ writel_relaxed(readl_relaxed(reg) | mask, reg);
+ }
+
+ static inline void st_i2c_clr_bits(void __iomem *reg, u32 mask)
+ {
+ writel_relaxed(readl_relaxed(reg) & ~mask, reg);
+ }
+
+ /* From I2C Specifications v0.5 */
+ static struct st_i2c_timings i2c_timings[] = {
+ [I2C_MODE_STANDARD] = {
+ .rate = 100000,
+ .rep_start_hold = 4000,
+ .rep_start_setup = 4700,
+ .start_hold = 4000,
+ .data_setup_time = 250,
+ .stop_setup_time = 4000,
+ .bus_free_time = 4700,
+ },
+ [I2C_MODE_FAST] = {
+ .rate = 400000,
+ .rep_start_hold = 600,
+ .rep_start_setup = 600,
+ .start_hold = 600,
+ .data_setup_time = 100,
+ .stop_setup_time = 600,
+ .bus_free_time = 1300,
+ },
+ };
+
+ static void st_i2c_flush_rx_fifo(struct st_i2c_dev *i2c_dev)
+ {
+ int count, i;
+
+ /*
+ * Counter only counts up to 7 but fifo size is 8...
+ * When fifo is full, counter is 0 and RIR bit of status register is
+ * set
+ */
+ if (readl_relaxed(i2c_dev->base + SSC_STA) & SSC_STA_RIR)
+ count = SSC_RXFIFO_SIZE;
+ else
+ count = readl_relaxed(i2c_dev->base + SSC_RX_FSTAT) &
+ SSC_RX_FSTAT_STATUS;
+
+ for (i = 0; i < count; i++)
+ readl_relaxed(i2c_dev->base + SSC_RBUF);
+ }
+
+ static void st_i2c_soft_reset(struct st_i2c_dev *i2c_dev)
+ {
+ /*
+ * FIFO needs to be emptied before reseting the IP,
+ * else the controller raises a BUSY error.
+ */
+ st_i2c_flush_rx_fifo(i2c_dev);
+
+ st_i2c_set_bits(i2c_dev->base + SSC_CTL, SSC_CTL_SR);
+ st_i2c_clr_bits(i2c_dev->base + SSC_CTL, SSC_CTL_SR);
+ }
+
+ /**
+ * st_i2c_hw_config() - Prepare SSC block, calculate and apply tuning timings
+ * @i2c_dev: Controller's private data
+ */
+ static void st_i2c_hw_config(struct st_i2c_dev *i2c_dev)
+ {
+ unsigned long rate;
+ u32 val, ns_per_clk;
+ struct st_i2c_timings *t = &i2c_timings[i2c_dev->mode];
+
+ st_i2c_soft_reset(i2c_dev);
+
+ val = SSC_CLR_REPSTRT | SSC_CLR_NACK | SSC_CLR_SSCARBL |
+ SSC_CLR_SSCAAS | SSC_CLR_SSCSTOP;
+ writel_relaxed(val, i2c_dev->base + SSC_CLR);
+
+ /* SSC Control register setup */
+ val = SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | SSC_CTL_DATA_WIDTH_9;
+ writel_relaxed(val, i2c_dev->base + SSC_CTL);
+
+ rate = clk_get_rate(i2c_dev->clk);
+ ns_per_clk = 1000000000 / rate;
+
+ /* Baudrate */
+ val = rate / (2 * t->rate);
+ writel_relaxed(val, i2c_dev->base + SSC_BRG);
+
+ /* Pre-scaler baudrate */
+ writel_relaxed(1, i2c_dev->base + SSC_PRE_SCALER_BRG);
+
+ /* Enable I2C mode */
+ writel_relaxed(SSC_I2C_I2CM, i2c_dev->base + SSC_I2C);
+
+ /* Repeated start hold time */
+ val = t->rep_start_hold / ns_per_clk;
+ writel_relaxed(val, i2c_dev->base + SSC_REP_START_HOLD);
+
+ /* Repeated start set up time */
+ val = t->rep_start_setup / ns_per_clk;
+ writel_relaxed(val, i2c_dev->base + SSC_REP_START_SETUP);
+
+ /* Start hold time */
+ val = t->start_hold / ns_per_clk;
+ writel_relaxed(val, i2c_dev->base + SSC_START_HOLD);
+
+ /* Data set up time */
+ val = t->data_setup_time / ns_per_clk;
+ writel_relaxed(val, i2c_dev->base + SSC_DATA_SETUP);
+
+ /* Stop set up time */
+ val = t->stop_setup_time / ns_per_clk;
+ writel_relaxed(val, i2c_dev->base + SSC_STOP_SETUP);
+
+ /* Bus free time */
+ val = t->bus_free_time / ns_per_clk;
+ writel_relaxed(val, i2c_dev->base + SSC_BUS_FREE);
+
+ /* Prescalers set up */
+ val = rate / 10000000;
+ writel_relaxed(val, i2c_dev->base + SSC_PRSCALER);
+ writel_relaxed(val, i2c_dev->base + SSC_PRSCALER_DATAOUT);
+
+ /* Noise suppression witdh */
+ val = i2c_dev->scl_min_width_us * rate / 100000000;
+ writel_relaxed(val, i2c_dev->base + SSC_NOISE_SUPP_WIDTH);
+
+ /* Noise suppression max output data delay width */
+ val = i2c_dev->sda_min_width_us * rate / 100000000;
+ writel_relaxed(val, i2c_dev->base + SSC_NOISE_SUPP_WIDTH_DATAOUT);
+ }
+
+ static int st_i2c_wait_free_bus(struct st_i2c_dev *i2c_dev)
+ {
+ u32 sta;
+ int i;
+
+ for (i = 0; i < 10; i++) {
+ sta = readl_relaxed(i2c_dev->base + SSC_STA);
+ if (!(sta & SSC_STA_BUSY))
+ return 0;
+
+ usleep_range(2000, 4000);
+ }
+
+ dev_err(i2c_dev->dev, "bus not free (status = 0x%08x)\n", sta);
+
+ return -EBUSY;
+ }
+
+ /**
+ * st_i2c_write_tx_fifo() - Write a byte in the Tx FIFO
+ * @i2c_dev: Controller's private data
+ * @byte: Data to write in the Tx FIFO
+ */
+ static inline void st_i2c_write_tx_fifo(struct st_i2c_dev *i2c_dev, u8 byte)
+ {
+ u16 tbuf = byte << 1;
+
+ writel_relaxed(tbuf | 1, i2c_dev->base + SSC_TBUF);
+ }
+
+ /**
+ * st_i2c_wr_fill_tx_fifo() - Fill the Tx FIFO in write mode
+ * @i2c_dev: Controller's private data
+ *
+ * This functions fills the Tx FIFO with I2C transfert buffer when
+ * in write mode.
+ */
+ static void st_i2c_wr_fill_tx_fifo(struct st_i2c_dev *i2c_dev)
+ {
+ struct st_i2c_client *c = &i2c_dev->client;
+ u32 tx_fstat, sta;
+ int i;
+
+ sta = readl_relaxed(i2c_dev->base + SSC_STA);
+ if (sta & SSC_STA_TX_FIFO_FULL)
+ return;
+
+ tx_fstat = readl_relaxed(i2c_dev->base + SSC_TX_FSTAT);
+ tx_fstat &= SSC_TX_FSTAT_STATUS;
+
+ if (c->count < (SSC_TXFIFO_SIZE - tx_fstat))
+ i = c->count;
+ else
+ i = SSC_TXFIFO_SIZE - tx_fstat;
+
+ for (; i > 0; i--, c->count--, c->buf++)
+ st_i2c_write_tx_fifo(i2c_dev, *c->buf);
+ }
+
+ /**
+ * st_i2c_rd_fill_tx_fifo() - Fill the Tx FIFO in read mode
+ * @i2c_dev: Controller's private data
+ *
+ * This functions fills the Tx FIFO with fixed pattern when
+ * in read mode to trigger clock.
+ */
+ static void st_i2c_rd_fill_tx_fifo(struct st_i2c_dev *i2c_dev, int max)
+ {
+ struct st_i2c_client *c = &i2c_dev->client;
+ u32 tx_fstat, sta;
+ int i;
+
+ sta = readl_relaxed(i2c_dev->base + SSC_STA);
+ if (sta & SSC_STA_TX_FIFO_FULL)
+ return;
+
+ tx_fstat = readl_relaxed(i2c_dev->base + SSC_TX_FSTAT);
+ tx_fstat &= SSC_TX_FSTAT_STATUS;
+
+ if (max < (SSC_TXFIFO_SIZE - tx_fstat))
+ i = max;
+ else
+ i = SSC_TXFIFO_SIZE - tx_fstat;
+
+ for (; i > 0; i--, c->xfered++)
+ st_i2c_write_tx_fifo(i2c_dev, 0xff);
+ }
+
+ static void st_i2c_read_rx_fifo(struct st_i2c_dev *i2c_dev)
+ {
+ struct st_i2c_client *c = &i2c_dev->client;
+ u32 i, sta;
+ u16 rbuf;
+
+ sta = readl_relaxed(i2c_dev->base + SSC_STA);
+ if (sta & SSC_STA_RIR) {
+ i = SSC_RXFIFO_SIZE;
+ } else {
+ i = readl_relaxed(i2c_dev->base + SSC_RX_FSTAT);
+ i &= SSC_RX_FSTAT_STATUS;
+ }
+
+ for (; (i > 0) && (c->count > 0); i--, c->count--) {
+ rbuf = readl_relaxed(i2c_dev->base + SSC_RBUF) >> 1;
+ *c->buf++ = (u8)rbuf & 0xff;
+ }
+
+ if (i) {
+ dev_err(i2c_dev->dev, "Unexpected %d bytes in rx fifo\n", i);
+ st_i2c_flush_rx_fifo(i2c_dev);
+ }
+ }
+
+ /**
+ * st_i2c_terminate_xfer() - Send either STOP or REPSTART condition
+ * @i2c_dev: Controller's private data
+ */
+ static void st_i2c_terminate_xfer(struct st_i2c_dev *i2c_dev)
+ {
+ struct st_i2c_client *c = &i2c_dev->client;
+
+ st_i2c_clr_bits(i2c_dev->base + SSC_IEN, SSC_IEN_TEEN);
+ st_i2c_clr_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STRTG);
+
+ if (c->stop) {
+ st_i2c_set_bits(i2c_dev->base + SSC_IEN, SSC_IEN_STOPEN);
+ st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STOPG);
+ } else {
+ st_i2c_set_bits(i2c_dev->base + SSC_IEN, SSC_IEN_REPSTRTEN);
+ st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_REPSTRTG);
+ }
+ }
+
+ /**
+ * st_i2c_handle_write() - Handle FIFO empty interrupt in case of write
+ * @i2c_dev: Controller's private data
+ */
+ static void st_i2c_handle_write(struct st_i2c_dev *i2c_dev)
+ {
+ struct st_i2c_client *c = &i2c_dev->client;
+
+ st_i2c_flush_rx_fifo(i2c_dev);
+
+ if (!c->count)
+ /* End of xfer, send stop or repstart */
+ st_i2c_terminate_xfer(i2c_dev);
+ else
+ st_i2c_wr_fill_tx_fifo(i2c_dev);
+ }
+
+ /**
+ * st_i2c_handle_write() - Handle FIFO enmpty interrupt in case of read
+ * @i2c_dev: Controller's private data
+ */
+ static void st_i2c_handle_read(struct st_i2c_dev *i2c_dev)
+ {
+ struct st_i2c_client *c = &i2c_dev->client;
+ u32 ien;
+
+ /* Trash the address read back */
+ if (!c->xfered) {
+ readl_relaxed(i2c_dev->base + SSC_RBUF);
+ st_i2c_clr_bits(i2c_dev->base + SSC_I2C, SSC_I2C_TXENB);
+ } else {
+ st_i2c_read_rx_fifo(i2c_dev);
+ }
+
+ if (!c->count) {
+ /* End of xfer, send stop or repstart */
+ st_i2c_terminate_xfer(i2c_dev);
+ } else if (c->count == 1) {
+ /* Penultimate byte to xfer, disable ACK gen. */
+ st_i2c_clr_bits(i2c_dev->base + SSC_I2C, SSC_I2C_ACKG);
+
+ /* Last received byte is to be handled by NACK interrupt */
+ ien = SSC_IEN_NACKEN | SSC_IEN_ARBLEN;
+ writel_relaxed(ien, i2c_dev->base + SSC_IEN);
+
+ st_i2c_rd_fill_tx_fifo(i2c_dev, c->count);
+ } else {
+ st_i2c_rd_fill_tx_fifo(i2c_dev, c->count - 1);
+ }
+ }
+
+ /**
+ * st_i2c_isr() - Interrupt routine
+ * @irq: interrupt number
+ * @data: Controller's private data
+ */
+ static irqreturn_t st_i2c_isr_thread(int irq, void *data)
+ {
+ struct st_i2c_dev *i2c_dev = data;
+ struct st_i2c_client *c = &i2c_dev->client;
+ u32 sta, ien;
+ int it;
+
+ ien = readl_relaxed(i2c_dev->base + SSC_IEN);
+ sta = readl_relaxed(i2c_dev->base + SSC_STA);
+
+ /* Use __fls() to check error bits first */
+ it = __fls(sta & ien);
+ if (it < 0) {
+ dev_dbg(i2c_dev->dev, "spurious it (sta=0x%04x, ien=0x%04x)\n",
+ sta, ien);
+ return IRQ_NONE;
+ }
+
+ switch (1 << it) {
+ case SSC_STA_TE:
+ if (c->addr & I2C_M_RD)
+ st_i2c_handle_read(i2c_dev);
+ else
+ st_i2c_handle_write(i2c_dev);
+ break;
+
+ case SSC_STA_STOP:
+ case SSC_STA_REPSTRT:
+ writel_relaxed(0, i2c_dev->base + SSC_IEN);
+ complete(&i2c_dev->complete);
+ break;
+
+ case SSC_STA_NACK:
+ writel_relaxed(SSC_CLR_NACK, i2c_dev->base + SSC_CLR);
+
+ /* Last received byte handled by NACK interrupt */
+ if ((c->addr & I2C_M_RD) && (c->count == 1) && (c->xfered)) {
+ st_i2c_handle_read(i2c_dev);
+ break;
+ }
+
+ it = SSC_IEN_STOPEN | SSC_IEN_ARBLEN;
+ writel_relaxed(it, i2c_dev->base + SSC_IEN);
+
+ st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STOPG);
+ c->result = -EIO;
+ break;
+
+ case SSC_STA_ARBL:
+ writel_relaxed(SSC_CLR_SSCARBL, i2c_dev->base + SSC_CLR);
+
+ it = SSC_IEN_STOPEN | SSC_IEN_ARBLEN;
+ writel_relaxed(it, i2c_dev->base + SSC_IEN);
+
+ st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STOPG);
+ c->result = -EIO;
+ break;
+
+ default:
+ dev_err(i2c_dev->dev,
+ "it %d unhandled (sta=0x%04x)\n", it, sta);
+ }
+
+ /*
+ * Read IEN register to ensure interrupt mask write is effective
+ * before re-enabling interrupt at GIC level, and thus avoid spurious
+ * interrupts.
+ */
+ readl(i2c_dev->base + SSC_IEN);
+
+ return IRQ_HANDLED;
+ }
+
+ /**
+ * st_i2c_xfer_msg() - Transfer a single I2C message
+ * @i2c_dev: Controller's private data
+ * @msg: I2C message to transfer
+ * @is_first: first message of the sequence
+ * @is_last: last message of the sequence
+ */
+ static int st_i2c_xfer_msg(struct st_i2c_dev *i2c_dev, struct i2c_msg *msg,
+ bool is_first, bool is_last)
+ {
+ struct st_i2c_client *c = &i2c_dev->client;
+ u32 ctl, i2c, it;
+ unsigned long timeout;
+ int ret;
+
+ c->addr = (u8)(msg->addr << 1);
+ c->addr |= (msg->flags & I2C_M_RD);
+ c->buf = msg->buf;
+ c->count = msg->len;
+ c->xfered = 0;
+ c->result = 0;
+ c->stop = is_last;
+
++ reinit_completion(&i2c_dev->complete);
+
+ ctl = SSC_CTL_EN | SSC_CTL_MS | SSC_CTL_EN_RX_FIFO | SSC_CTL_EN_TX_FIFO;
+ st_i2c_set_bits(i2c_dev->base + SSC_CTL, ctl);
+
+ i2c = SSC_I2C_TXENB;
+ if (c->addr & I2C_M_RD)
+ i2c |= SSC_I2C_ACKG;
+ st_i2c_set_bits(i2c_dev->base + SSC_I2C, i2c);
+
+ /* Write slave address */
+ st_i2c_write_tx_fifo(i2c_dev, c->addr);
+
+ /* Pre-fill Tx fifo with data in case of write */
+ if (!(c->addr & I2C_M_RD))
+ st_i2c_wr_fill_tx_fifo(i2c_dev);
+
+ it = SSC_IEN_NACKEN | SSC_IEN_TEEN | SSC_IEN_ARBLEN;
+ writel_relaxed(it, i2c_dev->base + SSC_IEN);
+
+ if (is_first) {
+ ret = st_i2c_wait_free_bus(i2c_dev);
+ if (ret)
+ return ret;
+
+ st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STRTG);
+ }
+
+ timeout = wait_for_completion_timeout(&i2c_dev->complete,
+ i2c_dev->adap.timeout);
+ ret = c->result;
+
+ if (!timeout) {
+ dev_err(i2c_dev->dev, "Write to slave 0x%x timed out\n",
+ c->addr);
+ ret = -ETIMEDOUT;
+ }
+
+ i2c = SSC_I2C_STOPG | SSC_I2C_REPSTRTG;
+ st_i2c_clr_bits(i2c_dev->base + SSC_I2C, i2c);
+
+ writel_relaxed(SSC_CLR_SSCSTOP | SSC_CLR_REPSTRT,
+ i2c_dev->base + SSC_CLR);
+
+ return ret;
+ }
+
+ /**
+ * st_i2c_xfer() - Transfer a single I2C message
+ * @i2c_adap: Adapter pointer to the controller
+ * @msgs: Pointer to data to be written.
+ * @num: Number of messages to be executed
+ */
+ static int st_i2c_xfer(struct i2c_adapter *i2c_adap,
+ struct i2c_msg msgs[], int num)
+ {
+ struct st_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
+ int ret, i;
+
+ i2c_dev->busy = true;
+
+ ret = clk_prepare_enable(i2c_dev->clk);
+ if (ret) {
+ dev_err(i2c_dev->dev, "Failed to prepare_enable clock\n");
+ return ret;
+ }
+
+ pinctrl_pm_select_default_state(i2c_dev->dev);
+
+ st_i2c_hw_config(i2c_dev);
+
+ for (i = 0; (i < num) && !ret; i++)
+ ret = st_i2c_xfer_msg(i2c_dev, &msgs[i], i == 0, i == num - 1);
+
+ pinctrl_pm_select_idle_state(i2c_dev->dev);
+
+ clk_disable_unprepare(i2c_dev->clk);
+
+ i2c_dev->busy = false;
+
+ return (ret < 0) ? ret : i;
+ }
+
+ #ifdef CONFIG_PM_SLEEP
+ static int st_i2c_suspend(struct device *dev)
+ {
+ struct platform_device *pdev =
+ container_of(dev, struct platform_device, dev);
+ struct st_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+ if (i2c_dev->busy)
+ return -EBUSY;
+
+ pinctrl_pm_select_sleep_state(dev);
+
+ return 0;
+ }
+
+ static int st_i2c_resume(struct device *dev)
+ {
+ pinctrl_pm_select_default_state(dev);
+ /* Go in idle state if available */
+ pinctrl_pm_select_idle_state(dev);
+
+ return 0;
+ }
+
+ static SIMPLE_DEV_PM_OPS(st_i2c_pm, st_i2c_suspend, st_i2c_resume);
+ #define ST_I2C_PM (&st_i2c_pm)
+ #else
+ #define ST_I2C_PM NULL
+ #endif
+
+ static u32 st_i2c_func(struct i2c_adapter *adap)
+ {
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+ }
+
+ static struct i2c_algorithm st_i2c_algo = {
+ .master_xfer = st_i2c_xfer,
+ .functionality = st_i2c_func,
+ };
+
+ static int st_i2c_of_get_deglitch(struct device_node *np,
+ struct st_i2c_dev *i2c_dev)
+ {
+ int ret;
+
+ ret = of_property_read_u32(np, "st,i2c-min-scl-pulse-width-us",
+ &i2c_dev->scl_min_width_us);
+ if ((ret == -ENODATA) || (ret == -EOVERFLOW)) {
+ dev_err(i2c_dev->dev, "st,i2c-min-scl-pulse-width-us invalid\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(np, "st,i2c-min-sda-pulse-width-us",
+ &i2c_dev->sda_min_width_us);
+ if ((ret == -ENODATA) || (ret == -EOVERFLOW)) {
+ dev_err(i2c_dev->dev, "st,i2c-min-sda-pulse-width-us invalid\n");
+ return ret;
+ }
+
+ return 0;
+ }
+
+ static int st_i2c_probe(struct platform_device *pdev)
+ {
+ struct device_node *np = pdev->dev.of_node;
+ struct st_i2c_dev *i2c_dev;
+ struct resource *res;
+ u32 clk_rate;
+ struct i2c_adapter *adap;
+ int ret;
+
+ i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
+ if (!i2c_dev)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ i2c_dev->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(i2c_dev->base))
+ return PTR_ERR(i2c_dev->base);
+
+ i2c_dev->irq = irq_of_parse_and_map(np, 0);
+ if (!i2c_dev->irq) {
+ dev_err(&pdev->dev, "IRQ missing or invalid\n");
+ return -EINVAL;
+ }
+
+ i2c_dev->clk = of_clk_get_by_name(np, "ssc");
+ if (IS_ERR(i2c_dev->clk)) {
+ dev_err(&pdev->dev, "Unable to request clock\n");
+ return PTR_ERR(i2c_dev->clk);
+ }
+
+ i2c_dev->mode = I2C_MODE_STANDARD;
+ ret = of_property_read_u32(np, "clock-frequency", &clk_rate);
+ if ((!ret) && (clk_rate == 400000))
+ i2c_dev->mode = I2C_MODE_FAST;
+
+ i2c_dev->dev = &pdev->dev;
+
+ ret = devm_request_threaded_irq(&pdev->dev, i2c_dev->irq,
+ NULL, st_i2c_isr_thread,
+ IRQF_ONESHOT, pdev->name, i2c_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
+ return ret;
+ }
+
+ pinctrl_pm_select_default_state(i2c_dev->dev);
+ /* In case idle state available, select it */
+ pinctrl_pm_select_idle_state(i2c_dev->dev);
+
+ ret = st_i2c_of_get_deglitch(np, i2c_dev);
+ if (ret)
+ return ret;
+
+ adap = &i2c_dev->adap;
+ i2c_set_adapdata(adap, i2c_dev);
+ snprintf(adap->name, sizeof(adap->name), "ST I2C(0x%x)", res->start);
+ adap->owner = THIS_MODULE;
+ adap->timeout = 2 * HZ;
+ adap->retries = 0;
+ adap->algo = &st_i2c_algo;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+
+ init_completion(&i2c_dev->complete);
+
+ ret = i2c_add_adapter(adap);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to add adapter\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, i2c_dev);
+
+ dev_info(i2c_dev->dev, "%s initialized\n", adap->name);
+
+ return 0;
+ }
+
+ static int st_i2c_remove(struct platform_device *pdev)
+ {
+ struct st_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c_dev->adap);
+
+ return 0;
+ }
+
+ static struct of_device_id st_i2c_match[] = {
+ { .compatible = "st,comms-ssc-i2c", },
+ { .compatible = "st,comms-ssc4-i2c", },
+ {},
+ };
+ MODULE_DEVICE_TABLE(of, st_i2c_match);
+
+ static struct platform_driver st_i2c_driver = {
+ .driver = {
+ .name = "st-i2c",
+ .owner = THIS_MODULE,
+ .of_match_table = st_i2c_match,
+ .pm = ST_I2C_PM,
+ },
+ .probe = st_i2c_probe,
+ .remove = st_i2c_remove,
+ };
+
+ module_platform_driver(st_i2c_driver);
+
+ MODULE_AUTHOR("Maxime Coquelin <maxime.coquelin@st.com>");
+ MODULE_DESCRIPTION("STMicroelectronics I2C driver");
+ MODULE_LICENSE("GPL v2");
client->flags & I2C_CLIENT_WAKE);
dev_dbg(dev, "probe\n");
+ acpi_dev_pm_attach(&client->dev, true);
status = driver->probe(client, i2c_match_id(driver->id_table, client));
- if (status)
+ if (status) {
- client->driver = NULL;
i2c_set_clientdata(client, NULL);
-
+ acpi_dev_pm_detach(&client->dev, true);
+ }
return status;
}
dev->driver = NULL;
status = 0;
}
- if (status == 0) {
- client->driver = NULL;
+ if (status == 0)
i2c_set_clientdata(client, NULL);
- }
-
+ acpi_dev_pm_detach(&client->dev, true);
return status;
}
projects / cascardo / linux.git / commitdiff