--- /dev/null
+Microchip PIC32 SPI Master controller
+
+Required properties:
+- compatible: Should be "microchip,pic32mzda-spi".
+- reg: Address and length of register space for the device.
+- interrupts: Should contain all three spi interrupts in sequence
+ of <fault-irq>, <receive-irq>, <transmit-irq>.
+- interrupt-names: Should be "fault", "rx", "tx" in order.
+- clocks: Phandle of the clock generating SPI clock on the bus.
+- clock-names: Should be "mck0".
+- cs-gpios: Specifies the gpio pins to be used for chipselects.
+ See: Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Optional properties:
+- dmas: Two or more DMA channel specifiers following the convention outlined
+ in Documentation/devicetree/bindings/dma/dma.txt
+- dma-names: Names for the dma channels. There must be at least one channel
+ named "spi-tx" for transmit and named "spi-rx" for receive.
+
+Example:
+
+spi1: spi@1f821000 {
+ compatible = "microchip,pic32mzda-spi";
+ reg = <0x1f821000 0x200>;
+ interrupts = <109 IRQ_TYPE_LEVEL_HIGH>,
+ <110 IRQ_TYPE_LEVEL_HIGH>,
+ <111 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-names = "fault", "rx", "tx";
+ clocks = <&PBCLK2>;
+ clock-names = "mck0";
+ cs-gpios = <&gpio3 4 GPIO_ACTIVE_LOW>;
+ dmas = <&dma 134>, <&dma 135>;
+ dma-names = "spi-rx", "spi-tx";
+};
--- /dev/null
+Microchip PIC32 Quad SPI controller
+-----------------------------------
+Required properties:
+- compatible: Should be "microchip,pic32mzda-sqi".
+- reg: Address and length of SQI controller register space.
+- interrupts: Should contain SQI interrupt.
+- clocks: Should contain phandle of two clocks in sequence, one that drives
+ clock on SPI bus and other that drives SQI controller.
+- clock-names: Should be "spi_ck" and "reg_ck" in order.
+
+Example:
+ sqi1: spi@1f8e2000 {
+ compatible = "microchip,pic32mzda-sqi";
+ reg = <0x1f8e2000 0x200>;
+ clocks = <&rootclk REF2CLK>, <&rootclk PB5CLK>;
+ clock-names = "spi_ck", "reg_ck";
+ interrupts = <169 IRQ_TYPE_LEVEL_HIGH>;
+ };
config SPI_ORION
tristate "Orion SPI master"
- depends on PLAT_ORION || COMPILE_TEST
+ depends on PLAT_ORION || ARCH_MVEBU || COMPILE_TEST
help
This enables using the SPI master controller on the Orion chips.
+config SPI_PIC32
+ tristate "Microchip PIC32 series SPI"
+ depends on MACH_PIC32 || COMPILE_TEST
+ help
+ SPI driver for Microchip PIC32 SPI master controller.
+
+config SPI_PIC32_SQI
+ tristate "Microchip PIC32 Quad SPI driver"
+ depends on MACH_PIC32 || COMPILE_TEST
+ depends on HAS_DMA
+ help
+ SPI driver for PIC32 Quad SPI controller.
+
config SPI_PL022
tristate "ARM AMBA PL022 SSP controller"
depends on ARM_AMBA
obj-$(CONFIG_SPI_OMAP24XX) += spi-omap2-mcspi.o
obj-$(CONFIG_SPI_TI_QSPI) += spi-ti-qspi.o
obj-$(CONFIG_SPI_ORION) += spi-orion.o
+obj-$(CONFIG_SPI_PIC32) += spi-pic32.o
+obj-$(CONFIG_SPI_PIC32_SQI) += spi-pic32-sqi.o
obj-$(CONFIG_SPI_PL022) += spi-pl022.o
obj-$(CONFIG_SPI_PPC4xx) += spi-ppc4xx.o
spi-pxa2xx-platform-objs := spi-pxa2xx.o spi-pxa2xx-dma.o
static int octeon_spi_probe(struct platform_device *pdev)
{
struct resource *res_mem;
+ void __iomem *reg_base;
struct spi_master *master;
struct octeon_spi *p;
int err = -ENOENT;
platform_set_drvdata(pdev, master);
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-
- if (res_mem == NULL) {
- dev_err(&pdev->dev, "found no memory resource\n");
- err = -ENXIO;
- goto fail;
- }
- if (!devm_request_mem_region(&pdev->dev, res_mem->start,
- resource_size(res_mem), res_mem->name)) {
- dev_err(&pdev->dev, "request_mem_region failed\n");
+ reg_base = devm_ioremap_resource(&pdev->dev, res_mem);
+ if (IS_ERR(reg_base)) {
+ err = PTR_ERR(reg_base);
goto fail;
}
- p->register_base = (u64)devm_ioremap(&pdev->dev, res_mem->start,
- resource_size(res_mem));
+
+ p->register_base = (u64)reg_base;
master->num_chipselect = 4;
master->mode_bits = SPI_CPHA |
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
-#include <linux/omap-dma.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/err.h>
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
- int dma_tx_sync_dev;
- int dma_rx_sync_dev;
-
struct completion dma_tx_completion;
struct completion dma_rx_completion;
struct spi_master *master = spi->master;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
- dma_cap_mask_t mask;
- unsigned sig;
+ int ret = 0;
mcspi = spi_master_get_devdata(master);
mcspi_dma = mcspi->dma_channels + spi->chip_select;
init_completion(&mcspi_dma->dma_rx_completion);
init_completion(&mcspi_dma->dma_tx_completion);
- dma_cap_zero(mask);
- dma_cap_set(DMA_SLAVE, mask);
- sig = mcspi_dma->dma_rx_sync_dev;
-
- mcspi_dma->dma_rx =
- dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
- &sig, &master->dev,
- mcspi_dma->dma_rx_ch_name);
- if (!mcspi_dma->dma_rx)
+ mcspi_dma->dma_rx = dma_request_chan(&master->dev,
+ mcspi_dma->dma_rx_ch_name);
+ if (IS_ERR(mcspi_dma->dma_rx)) {
+ ret = PTR_ERR(mcspi_dma->dma_rx);
+ mcspi_dma->dma_rx = NULL;
goto no_dma;
+ }
- sig = mcspi_dma->dma_tx_sync_dev;
- mcspi_dma->dma_tx =
- dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
- &sig, &master->dev,
- mcspi_dma->dma_tx_ch_name);
-
- if (!mcspi_dma->dma_tx) {
+ mcspi_dma->dma_tx = dma_request_chan(&master->dev,
+ mcspi_dma->dma_tx_ch_name);
+ if (IS_ERR(mcspi_dma->dma_tx)) {
+ ret = PTR_ERR(mcspi_dma->dma_tx);
+ mcspi_dma->dma_tx = NULL;
dma_release_channel(mcspi_dma->dma_rx);
mcspi_dma->dma_rx = NULL;
- goto no_dma;
}
- return 0;
-
no_dma:
- dev_warn(&spi->dev, "not using DMA for McSPI\n");
- return -EAGAIN;
+ return ret;
}
static int omap2_mcspi_setup(struct spi_device *spi)
if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
ret = omap2_mcspi_request_dma(spi);
- if (ret < 0 && ret != -EAGAIN)
- return ret;
+ if (ret)
+ dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n",
+ ret);
}
ret = pm_runtime_get_sync(mcspi->dev);
}
for (i = 0; i < master->num_chipselect; i++) {
- char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
- char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
- struct resource *dma_res;
-
- sprintf(dma_rx_ch_name, "rx%d", i);
- if (!pdev->dev.of_node) {
- dma_res =
- platform_get_resource_byname(pdev,
- IORESOURCE_DMA,
- dma_rx_ch_name);
- if (!dma_res) {
- dev_dbg(&pdev->dev,
- "cannot get DMA RX channel\n");
- status = -ENODEV;
- break;
- }
-
- mcspi->dma_channels[i].dma_rx_sync_dev =
- dma_res->start;
- }
- sprintf(dma_tx_ch_name, "tx%d", i);
- if (!pdev->dev.of_node) {
- dma_res =
- platform_get_resource_byname(pdev,
- IORESOURCE_DMA,
- dma_tx_ch_name);
- if (!dma_res) {
- dev_dbg(&pdev->dev,
- "cannot get DMA TX channel\n");
- status = -ENODEV;
- break;
- }
-
- mcspi->dma_channels[i].dma_tx_sync_dev =
- dma_res->start;
- }
+ sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
+ sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
}
if (status < 0)
--- /dev/null
+/*
+ * PIC32 Quad SPI controller driver.
+ *
+ * Purna Chandra Mandal <purna.mandal@microchip.com>
+ * Copyright (c) 2016, Microchip Technology Inc.
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+/* SQI registers */
+#define PESQI_XIP_CONF1_REG 0x00
+#define PESQI_XIP_CONF2_REG 0x04
+#define PESQI_CONF_REG 0x08
+#define PESQI_CTRL_REG 0x0C
+#define PESQI_CLK_CTRL_REG 0x10
+#define PESQI_CMD_THRES_REG 0x14
+#define PESQI_INT_THRES_REG 0x18
+#define PESQI_INT_ENABLE_REG 0x1C
+#define PESQI_INT_STAT_REG 0x20
+#define PESQI_TX_DATA_REG 0x24
+#define PESQI_RX_DATA_REG 0x28
+#define PESQI_STAT1_REG 0x2C
+#define PESQI_STAT2_REG 0x30
+#define PESQI_BD_CTRL_REG 0x34
+#define PESQI_BD_CUR_ADDR_REG 0x38
+#define PESQI_BD_BASE_ADDR_REG 0x40
+#define PESQI_BD_STAT_REG 0x44
+#define PESQI_BD_POLL_CTRL_REG 0x48
+#define PESQI_BD_TX_DMA_STAT_REG 0x4C
+#define PESQI_BD_RX_DMA_STAT_REG 0x50
+#define PESQI_THRES_REG 0x54
+#define PESQI_INT_SIGEN_REG 0x58
+
+/* PESQI_CONF_REG fields */
+#define PESQI_MODE 0x7
+#define PESQI_MODE_BOOT 0
+#define PESQI_MODE_PIO 1
+#define PESQI_MODE_DMA 2
+#define PESQI_MODE_XIP 3
+#define PESQI_MODE_SHIFT 0
+#define PESQI_CPHA BIT(3)
+#define PESQI_CPOL BIT(4)
+#define PESQI_LSBF BIT(5)
+#define PESQI_RXLATCH BIT(7)
+#define PESQI_SERMODE BIT(8)
+#define PESQI_WP_EN BIT(9)
+#define PESQI_HOLD_EN BIT(10)
+#define PESQI_BURST_EN BIT(12)
+#define PESQI_CS_CTRL_HW BIT(15)
+#define PESQI_SOFT_RESET BIT(16)
+#define PESQI_LANES_SHIFT 20
+#define PESQI_SINGLE_LANE 0
+#define PESQI_DUAL_LANE 1
+#define PESQI_QUAD_LANE 2
+#define PESQI_CSEN_SHIFT 24
+#define PESQI_EN BIT(23)
+
+/* PESQI_CLK_CTRL_REG fields */
+#define PESQI_CLK_EN BIT(0)
+#define PESQI_CLK_STABLE BIT(1)
+#define PESQI_CLKDIV_SHIFT 8
+#define PESQI_CLKDIV 0xff
+
+/* PESQI_INT_THR/CMD_THR_REG */
+#define PESQI_TXTHR_MASK 0x1f
+#define PESQI_TXTHR_SHIFT 8
+#define PESQI_RXTHR_MASK 0x1f
+#define PESQI_RXTHR_SHIFT 0
+
+/* PESQI_INT_EN/INT_STAT/INT_SIG_EN_REG */
+#define PESQI_TXEMPTY BIT(0)
+#define PESQI_TXFULL BIT(1)
+#define PESQI_TXTHR BIT(2)
+#define PESQI_RXEMPTY BIT(3)
+#define PESQI_RXFULL BIT(4)
+#define PESQI_RXTHR BIT(5)
+#define PESQI_BDDONE BIT(9) /* BD processing complete */
+#define PESQI_PKTCOMP BIT(10) /* packet processing complete */
+#define PESQI_DMAERR BIT(11) /* error */
+
+/* PESQI_BD_CTRL_REG */
+#define PESQI_DMA_EN BIT(0) /* enable DMA engine */
+#define PESQI_POLL_EN BIT(1) /* enable polling */
+#define PESQI_BDP_START BIT(2) /* start BD processor */
+
+/* PESQI controller buffer descriptor */
+struct buf_desc {
+ u32 bd_ctrl; /* control */
+ u32 bd_status; /* reserved */
+ u32 bd_addr; /* DMA buffer addr */
+ u32 bd_nextp; /* next item in chain */
+};
+
+/* bd_ctrl */
+#define BD_BUFLEN 0x1ff
+#define BD_CBD_INT_EN BIT(16) /* Current BD is processed */
+#define BD_PKT_INT_EN BIT(17) /* All BDs of PKT processed */
+#define BD_LIFM BIT(18) /* last data of pkt */
+#define BD_LAST BIT(19) /* end of list */
+#define BD_DATA_RECV BIT(20) /* receive data */
+#define BD_DDR BIT(21) /* DDR mode */
+#define BD_DUAL BIT(22) /* Dual SPI */
+#define BD_QUAD BIT(23) /* Quad SPI */
+#define BD_LSBF BIT(25) /* LSB First */
+#define BD_STAT_CHECK BIT(27) /* Status poll */
+#define BD_DEVSEL_SHIFT 28 /* CS */
+#define BD_CS_DEASSERT BIT(30) /* de-assert CS after current BD */
+#define BD_EN BIT(31) /* BD owned by H/W */
+
+/**
+ * struct ring_desc - Representation of SQI ring descriptor
+ * @list: list element to add to free or used list.
+ * @bd: PESQI controller buffer descriptor
+ * @bd_dma: DMA address of PESQI controller buffer descriptor
+ * @xfer_len: transfer length
+ */
+struct ring_desc {
+ struct list_head list;
+ struct buf_desc *bd;
+ dma_addr_t bd_dma;
+ u32 xfer_len;
+};
+
+/* Global constants */
+#define PESQI_BD_BUF_LEN_MAX 256
+#define PESQI_BD_COUNT 256 /* max 64KB data per spi message */
+
+struct pic32_sqi {
+ void __iomem *regs;
+ struct clk *sys_clk;
+ struct clk *base_clk; /* drives spi clock */
+ struct spi_master *master;
+ int irq;
+ struct completion xfer_done;
+ struct ring_desc *ring;
+ void *bd;
+ dma_addr_t bd_dma;
+ struct list_head bd_list_free; /* free */
+ struct list_head bd_list_used; /* allocated */
+ struct spi_device *cur_spi;
+ u32 cur_speed;
+ u8 cur_mode;
+};
+
+static inline void pic32_setbits(void __iomem *reg, u32 set)
+{
+ writel(readl(reg) | set, reg);
+}
+
+static inline void pic32_clrbits(void __iomem *reg, u32 clr)
+{
+ writel(readl(reg) & ~clr, reg);
+}
+
+static int pic32_sqi_set_clk_rate(struct pic32_sqi *sqi, u32 sck)
+{
+ u32 val, div;
+
+ /* div = base_clk / (2 * spi_clk) */
+ div = clk_get_rate(sqi->base_clk) / (2 * sck);
+ div &= PESQI_CLKDIV;
+
+ val = readl(sqi->regs + PESQI_CLK_CTRL_REG);
+ /* apply new divider */
+ val &= ~(PESQI_CLK_STABLE | (PESQI_CLKDIV << PESQI_CLKDIV_SHIFT));
+ val |= div << PESQI_CLKDIV_SHIFT;
+ writel(val, sqi->regs + PESQI_CLK_CTRL_REG);
+
+ /* wait for stability */
+ return readl_poll_timeout(sqi->regs + PESQI_CLK_CTRL_REG, val,
+ val & PESQI_CLK_STABLE, 1, 5000);
+}
+
+static inline void pic32_sqi_enable_int(struct pic32_sqi *sqi)
+{
+ u32 mask = PESQI_DMAERR | PESQI_BDDONE | PESQI_PKTCOMP;
+
+ writel(mask, sqi->regs + PESQI_INT_ENABLE_REG);
+ /* INT_SIGEN works as interrupt-gate to INTR line */
+ writel(mask, sqi->regs + PESQI_INT_SIGEN_REG);
+}
+
+static inline void pic32_sqi_disable_int(struct pic32_sqi *sqi)
+{
+ writel(0, sqi->regs + PESQI_INT_ENABLE_REG);
+ writel(0, sqi->regs + PESQI_INT_SIGEN_REG);
+}
+
+static irqreturn_t pic32_sqi_isr(int irq, void *dev_id)
+{
+ struct pic32_sqi *sqi = dev_id;
+ u32 enable, status;
+
+ enable = readl(sqi->regs + PESQI_INT_ENABLE_REG);
+ status = readl(sqi->regs + PESQI_INT_STAT_REG);
+
+ /* check spurious interrupt */
+ if (!status)
+ return IRQ_NONE;
+
+ if (status & PESQI_DMAERR) {
+ enable = 0;
+ goto irq_done;
+ }
+
+ if (status & PESQI_TXTHR)
+ enable &= ~(PESQI_TXTHR | PESQI_TXFULL | PESQI_TXEMPTY);
+
+ if (status & PESQI_RXTHR)
+ enable &= ~(PESQI_RXTHR | PESQI_RXFULL | PESQI_RXEMPTY);
+
+ if (status & PESQI_BDDONE)
+ enable &= ~PESQI_BDDONE;
+
+ /* packet processing completed */
+ if (status & PESQI_PKTCOMP) {
+ /* mask all interrupts */
+ enable = 0;
+ /* complete trasaction */
+ complete(&sqi->xfer_done);
+ }
+
+irq_done:
+ /* interrupts are sticky, so mask when handled */
+ writel(enable, sqi->regs + PESQI_INT_ENABLE_REG);
+
+ return IRQ_HANDLED;
+}
+
+static struct ring_desc *ring_desc_get(struct pic32_sqi *sqi)
+{
+ struct ring_desc *rdesc;
+
+ if (list_empty(&sqi->bd_list_free))
+ return NULL;
+
+ rdesc = list_first_entry(&sqi->bd_list_free, struct ring_desc, list);
+ list_del(&rdesc->list);
+ list_add_tail(&rdesc->list, &sqi->bd_list_used);
+ return rdesc;
+}
+
+static void ring_desc_put(struct pic32_sqi *sqi, struct ring_desc *rdesc)
+{
+ list_del(&rdesc->list);
+ list_add(&rdesc->list, &sqi->bd_list_free);
+}
+
+static int pic32_sqi_one_transfer(struct pic32_sqi *sqi,
+ struct spi_message *mesg,
+ struct spi_transfer *xfer)
+{
+ struct spi_device *spi = mesg->spi;
+ struct scatterlist *sg, *sgl;
+ struct ring_desc *rdesc;
+ struct buf_desc *bd;
+ int nents, i;
+ u32 bd_ctrl;
+ u32 nbits;
+
+ /* Device selection */
+ bd_ctrl = spi->chip_select << BD_DEVSEL_SHIFT;
+
+ /* half-duplex: select transfer buffer, direction and lane */
+ if (xfer->rx_buf) {
+ bd_ctrl |= BD_DATA_RECV;
+ nbits = xfer->rx_nbits;
+ sgl = xfer->rx_sg.sgl;
+ nents = xfer->rx_sg.nents;
+ } else {
+ nbits = xfer->tx_nbits;
+ sgl = xfer->tx_sg.sgl;
+ nents = xfer->tx_sg.nents;
+ }
+
+ if (nbits & SPI_NBITS_QUAD)
+ bd_ctrl |= BD_QUAD;
+ else if (nbits & SPI_NBITS_DUAL)
+ bd_ctrl |= BD_DUAL;
+
+ /* LSB first */
+ if (spi->mode & SPI_LSB_FIRST)
+ bd_ctrl |= BD_LSBF;
+
+ /* ownership to hardware */
+ bd_ctrl |= BD_EN;
+
+ for_each_sg(sgl, sg, nents, i) {
+ /* get ring descriptor */
+ rdesc = ring_desc_get(sqi);
+ if (!rdesc)
+ break;
+
+ bd = rdesc->bd;
+
+ /* BD CTRL: length */
+ rdesc->xfer_len = sg_dma_len(sg);
+ bd->bd_ctrl = bd_ctrl;
+ bd->bd_ctrl |= rdesc->xfer_len;
+
+ /* BD STAT */
+ bd->bd_status = 0;
+
+ /* BD BUFFER ADDRESS */
+ bd->bd_addr = sg->dma_address;
+ }
+
+ return 0;
+}
+
+static int pic32_sqi_prepare_hardware(struct spi_master *master)
+{
+ struct pic32_sqi *sqi = spi_master_get_devdata(master);
+
+ /* enable spi interface */
+ pic32_setbits(sqi->regs + PESQI_CONF_REG, PESQI_EN);
+ /* enable spi clk */
+ pic32_setbits(sqi->regs + PESQI_CLK_CTRL_REG, PESQI_CLK_EN);
+
+ return 0;
+}
+
+static bool pic32_sqi_can_dma(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *x)
+{
+ /* Do DMA irrespective of transfer size */
+ return true;
+}
+
+static int pic32_sqi_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct spi_device *spi = msg->spi;
+ struct ring_desc *rdesc, *next;
+ struct spi_transfer *xfer;
+ struct pic32_sqi *sqi;
+ int ret = 0, mode;
+ u32 val;
+
+ sqi = spi_master_get_devdata(master);
+
+ reinit_completion(&sqi->xfer_done);
+ msg->actual_length = 0;
+
+ /* We can't handle spi_transfer specific "speed_hz", "bits_per_word"
+ * and "delay_usecs". But spi_device specific speed and mode change
+ * can be handled at best during spi chip-select switch.
+ */
+ if (sqi->cur_spi != spi) {
+ /* set spi speed */
+ if (sqi->cur_speed != spi->max_speed_hz) {
+ sqi->cur_speed = spi->max_speed_hz;
+ ret = pic32_sqi_set_clk_rate(sqi, spi->max_speed_hz);
+ if (ret)
+ dev_warn(&spi->dev, "set_clk, %d\n", ret);
+ }
+
+ /* set spi mode */
+ mode = spi->mode & (SPI_MODE_3 | SPI_LSB_FIRST);
+ if (sqi->cur_mode != mode) {
+ val = readl(sqi->regs + PESQI_CONF_REG);
+ val &= ~(PESQI_CPOL | PESQI_CPHA | PESQI_LSBF);
+ if (mode & SPI_CPOL)
+ val |= PESQI_CPOL;
+ if (mode & SPI_LSB_FIRST)
+ val |= PESQI_LSBF;
+ val |= PESQI_CPHA;
+ writel(val, sqi->regs + PESQI_CONF_REG);
+
+ sqi->cur_mode = mode;
+ }
+ sqi->cur_spi = spi;
+ }
+
+ /* prepare hardware desc-list(BD) for transfer(s) */
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ ret = pic32_sqi_one_transfer(sqi, msg, xfer);
+ if (ret) {
+ dev_err(&spi->dev, "xfer %p err\n", xfer);
+ goto xfer_out;
+ }
+ }
+
+ /* BDs are prepared and chained. Now mark LAST_BD, CS_DEASSERT at last
+ * element of the list.
+ */
+ rdesc = list_last_entry(&sqi->bd_list_used, struct ring_desc, list);
+ rdesc->bd->bd_ctrl |= BD_LAST | BD_CS_DEASSERT |
+ BD_LIFM | BD_PKT_INT_EN;
+
+ /* set base address BD list for DMA engine */
+ rdesc = list_first_entry(&sqi->bd_list_used, struct ring_desc, list);
+ writel(rdesc->bd_dma, sqi->regs + PESQI_BD_BASE_ADDR_REG);
+
+ /* enable interrupt */
+ pic32_sqi_enable_int(sqi);
+
+ /* enable DMA engine */
+ val = PESQI_DMA_EN | PESQI_POLL_EN | PESQI_BDP_START;
+ writel(val, sqi->regs + PESQI_BD_CTRL_REG);
+
+ /* wait for xfer completion */
+ ret = wait_for_completion_timeout(&sqi->xfer_done, 5 * HZ);
+ if (ret <= 0) {
+ dev_err(&sqi->master->dev, "wait timedout/interrupted\n");
+ ret = -EIO;
+ msg->status = ret;
+ } else {
+ /* success */
+ msg->status = 0;
+ ret = 0;
+ }
+
+ /* disable DMA */
+ writel(0, sqi->regs + PESQI_BD_CTRL_REG);
+
+ pic32_sqi_disable_int(sqi);
+
+xfer_out:
+ list_for_each_entry_safe_reverse(rdesc, next,
+ &sqi->bd_list_used, list) {
+ /* Update total byte transferred */
+ msg->actual_length += rdesc->xfer_len;
+ /* release ring descr */
+ ring_desc_put(sqi, rdesc);
+ }
+ spi_finalize_current_message(spi->master);
+
+ return ret;
+}
+
+static int pic32_sqi_unprepare_hardware(struct spi_master *master)
+{
+ struct pic32_sqi *sqi = spi_master_get_devdata(master);
+
+ /* disable clk */
+ pic32_clrbits(sqi->regs + PESQI_CLK_CTRL_REG, PESQI_CLK_EN);
+ /* disable spi */
+ pic32_clrbits(sqi->regs + PESQI_CONF_REG, PESQI_EN);
+
+ return 0;
+}
+
+static int ring_desc_ring_alloc(struct pic32_sqi *sqi)
+{
+ struct ring_desc *rdesc;
+ struct buf_desc *bd;
+ int i;
+
+ /* allocate coherent DMAable memory for hardware buffer descriptors. */
+ sqi->bd = dma_zalloc_coherent(&sqi->master->dev,
+ sizeof(*bd) * PESQI_BD_COUNT,
+ &sqi->bd_dma, GFP_DMA32);
+ if (!sqi->bd) {
+ dev_err(&sqi->master->dev, "failed allocating dma buffer\n");
+ return -ENOMEM;
+ }
+
+ /* allocate software ring descriptors */
+ sqi->ring = kcalloc(PESQI_BD_COUNT, sizeof(*rdesc), GFP_KERNEL);
+ if (!sqi->ring) {
+ dma_free_coherent(&sqi->master->dev,
+ sizeof(*bd) * PESQI_BD_COUNT,
+ sqi->bd, sqi->bd_dma);
+ return -ENOMEM;
+ }
+
+ bd = (struct buf_desc *)sqi->bd;
+
+ INIT_LIST_HEAD(&sqi->bd_list_free);
+ INIT_LIST_HEAD(&sqi->bd_list_used);
+
+ /* initialize ring-desc */
+ for (i = 0, rdesc = sqi->ring; i < PESQI_BD_COUNT; i++, rdesc++) {
+ INIT_LIST_HEAD(&rdesc->list);
+ rdesc->bd = &bd[i];
+ rdesc->bd_dma = sqi->bd_dma + (void *)&bd[i] - (void *)bd;
+ list_add_tail(&rdesc->list, &sqi->bd_list_free);
+ }
+
+ /* Prepare BD: chain to next BD(s) */
+ for (i = 0, rdesc = sqi->ring; i < PESQI_BD_COUNT - 1; i++)
+ bd[i].bd_nextp = rdesc[i + 1].bd_dma;
+ bd[PESQI_BD_COUNT - 1].bd_nextp = 0;
+
+ return 0;
+}
+
+static void ring_desc_ring_free(struct pic32_sqi *sqi)
+{
+ dma_free_coherent(&sqi->master->dev,
+ sizeof(struct buf_desc) * PESQI_BD_COUNT,
+ sqi->bd, sqi->bd_dma);
+ kfree(sqi->ring);
+}
+
+static void pic32_sqi_hw_init(struct pic32_sqi *sqi)
+{
+ unsigned long flags;
+ u32 val;
+
+ /* Soft-reset of PESQI controller triggers interrupt.
+ * We are not yet ready to handle them so disable CPU
+ * interrupt for the time being.
+ */
+ local_irq_save(flags);
+
+ /* assert soft-reset */
+ writel(PESQI_SOFT_RESET, sqi->regs + PESQI_CONF_REG);
+
+ /* wait until clear */
+ readl_poll_timeout_atomic(sqi->regs + PESQI_CONF_REG, val,
+ !(val & PESQI_SOFT_RESET), 1, 5000);
+
+ /* disable all interrupts */
+ pic32_sqi_disable_int(sqi);
+
+ /* Now it is safe to enable back CPU interrupt */
+ local_irq_restore(flags);
+
+ /* tx and rx fifo interrupt threshold */
+ val = readl(sqi->regs + PESQI_CMD_THRES_REG);
+ val &= ~(PESQI_TXTHR_MASK << PESQI_TXTHR_SHIFT);
+ val &= ~(PESQI_RXTHR_MASK << PESQI_RXTHR_SHIFT);
+ val |= (1U << PESQI_TXTHR_SHIFT) | (1U << PESQI_RXTHR_SHIFT);
+ writel(val, sqi->regs + PESQI_CMD_THRES_REG);
+
+ val = readl(sqi->regs + PESQI_INT_THRES_REG);
+ val &= ~(PESQI_TXTHR_MASK << PESQI_TXTHR_SHIFT);
+ val &= ~(PESQI_RXTHR_MASK << PESQI_RXTHR_SHIFT);
+ val |= (1U << PESQI_TXTHR_SHIFT) | (1U << PESQI_RXTHR_SHIFT);
+ writel(val, sqi->regs + PESQI_INT_THRES_REG);
+
+ /* default configuration */
+ val = readl(sqi->regs + PESQI_CONF_REG);
+
+ /* set mode: DMA */
+ val &= ~PESQI_MODE;
+ val |= PESQI_MODE_DMA << PESQI_MODE_SHIFT;
+ writel(val, sqi->regs + PESQI_CONF_REG);
+
+ /* DATAEN - SQIID0-ID3 */
+ val |= PESQI_QUAD_LANE << PESQI_LANES_SHIFT;
+
+ /* burst/INCR4 enable */
+ val |= PESQI_BURST_EN;
+
+ /* CSEN - all CS */
+ val |= 3U << PESQI_CSEN_SHIFT;
+ writel(val, sqi->regs + PESQI_CONF_REG);
+
+ /* write poll count */
+ writel(0, sqi->regs + PESQI_BD_POLL_CTRL_REG);
+
+ sqi->cur_speed = 0;
+ sqi->cur_mode = -1;
+}
+
+static int pic32_sqi_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct pic32_sqi *sqi;
+ struct resource *reg;
+ int ret;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*sqi));
+ if (!master)
+ return -ENOMEM;
+
+ sqi = spi_master_get_devdata(master);
+ sqi->master = master;
+
+ reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ sqi->regs = devm_ioremap_resource(&pdev->dev, reg);
+ if (IS_ERR(sqi->regs)) {
+ ret = PTR_ERR(sqi->regs);
+ goto err_free_master;
+ }
+
+ /* irq */
+ sqi->irq = platform_get_irq(pdev, 0);
+ if (sqi->irq < 0) {
+ dev_err(&pdev->dev, "no irq found\n");
+ ret = sqi->irq;
+ goto err_free_master;
+ }
+
+ /* clocks */
+ sqi->sys_clk = devm_clk_get(&pdev->dev, "reg_ck");
+ if (IS_ERR(sqi->sys_clk)) {
+ ret = PTR_ERR(sqi->sys_clk);
+ dev_err(&pdev->dev, "no sys_clk ?\n");
+ goto err_free_master;
+ }
+
+ sqi->base_clk = devm_clk_get(&pdev->dev, "spi_ck");
+ if (IS_ERR(sqi->base_clk)) {
+ ret = PTR_ERR(sqi->base_clk);
+ dev_err(&pdev->dev, "no base clk ?\n");
+ goto err_free_master;
+ }
+
+ ret = clk_prepare_enable(sqi->sys_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "sys clk enable failed\n");
+ goto err_free_master;
+ }
+
+ ret = clk_prepare_enable(sqi->base_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "base clk enable failed\n");
+ clk_disable_unprepare(sqi->sys_clk);
+ goto err_free_master;
+ }
+
+ init_completion(&sqi->xfer_done);
+
+ /* initialize hardware */
+ pic32_sqi_hw_init(sqi);
+
+ /* allocate buffers & descriptors */
+ ret = ring_desc_ring_alloc(sqi);
+ if (ret) {
+ dev_err(&pdev->dev, "ring alloc failed\n");
+ goto err_disable_clk;
+ }
+
+ /* install irq handlers */
+ ret = request_irq(sqi->irq, pic32_sqi_isr, 0,
+ dev_name(&pdev->dev), sqi);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "request_irq(%d), failed\n", sqi->irq);
+ goto err_free_ring;
+ }
+
+ /* register master */
+ master->num_chipselect = 2;
+ master->max_speed_hz = clk_get_rate(sqi->base_clk);
+ master->dma_alignment = 32;
+ master->max_dma_len = PESQI_BD_BUF_LEN_MAX;
+ master->dev.of_node = of_node_get(pdev->dev.of_node);
+ master->mode_bits = SPI_MODE_3 | SPI_MODE_0 | SPI_TX_DUAL |
+ SPI_RX_DUAL | SPI_TX_QUAD | SPI_RX_QUAD;
+ master->flags = SPI_MASTER_HALF_DUPLEX;
+ master->can_dma = pic32_sqi_can_dma;
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
+ master->transfer_one_message = pic32_sqi_one_message;
+ master->prepare_transfer_hardware = pic32_sqi_prepare_hardware;
+ master->unprepare_transfer_hardware = pic32_sqi_unprepare_hardware;
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (ret) {
+ dev_err(&master->dev, "failed registering spi master\n");
+ free_irq(sqi->irq, sqi);
+ goto err_free_ring;
+ }
+
+ platform_set_drvdata(pdev, sqi);
+
+ return 0;
+
+err_free_ring:
+ ring_desc_ring_free(sqi);
+
+err_disable_clk:
+ clk_disable_unprepare(sqi->base_clk);
+ clk_disable_unprepare(sqi->sys_clk);
+
+err_free_master:
+ spi_master_put(master);
+ return ret;
+}
+
+static int pic32_sqi_remove(struct platform_device *pdev)
+{
+ struct pic32_sqi *sqi = platform_get_drvdata(pdev);
+
+ /* release resources */
+ free_irq(sqi->irq, sqi);
+ ring_desc_ring_free(sqi);
+
+ /* disable clk */
+ clk_disable_unprepare(sqi->base_clk);
+ clk_disable_unprepare(sqi->sys_clk);
+
+ return 0;
+}
+
+static const struct of_device_id pic32_sqi_of_ids[] = {
+ {.compatible = "microchip,pic32mzda-sqi",},
+ {},
+};
+MODULE_DEVICE_TABLE(of, pic32_sqi_of_ids);
+
+static struct platform_driver pic32_sqi_driver = {
+ .driver = {
+ .name = "sqi-pic32",
+ .of_match_table = of_match_ptr(pic32_sqi_of_ids),
+ },
+ .probe = pic32_sqi_probe,
+ .remove = pic32_sqi_remove,
+};
+
+module_platform_driver(pic32_sqi_driver);
+
+MODULE_AUTHOR("Purna Chandra Mandal <purna.mandal@microchip.com>");
+MODULE_DESCRIPTION("Microchip SPI driver for PIC32 SQI controller.");
+MODULE_LICENSE("GPL v2");
--- /dev/null
+/*
+ * Microchip PIC32 SPI controller driver.
+ *
+ * Purna Chandra Mandal <purna.mandal@microchip.com>
+ * Copyright (c) 2016, Microchip Technology Inc.
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+
+/* SPI controller registers */
+struct pic32_spi_regs {
+ u32 ctrl;
+ u32 ctrl_clr;
+ u32 ctrl_set;
+ u32 ctrl_inv;
+ u32 status;
+ u32 status_clr;
+ u32 status_set;
+ u32 status_inv;
+ u32 buf;
+ u32 dontuse[3];
+ u32 baud;
+ u32 dontuse2[3];
+ u32 ctrl2;
+ u32 ctrl2_clr;
+ u32 ctrl2_set;
+ u32 ctrl2_inv;
+};
+
+/* Bit fields of SPI Control Register */
+#define CTRL_RX_INT_SHIFT 0 /* Rx interrupt generation */
+#define RX_FIFO_EMTPY 0
+#define RX_FIFO_NOT_EMPTY 1 /* not empty */
+#define RX_FIFO_HALF_FULL 2 /* full by half or more */
+#define RX_FIFO_FULL 3 /* completely full */
+
+#define CTRL_TX_INT_SHIFT 2 /* TX interrupt generation */
+#define TX_FIFO_ALL_EMPTY 0 /* completely empty */
+#define TX_FIFO_EMTPY 1 /* empty */
+#define TX_FIFO_HALF_EMPTY 2 /* empty by half or more */
+#define TX_FIFO_NOT_FULL 3 /* atleast one empty */
+
+#define CTRL_MSTEN BIT(5) /* enable master mode */
+#define CTRL_CKP BIT(6) /* active low */
+#define CTRL_CKE BIT(8) /* Tx on falling edge */
+#define CTRL_SMP BIT(9) /* Rx at middle or end of tx */
+#define CTRL_BPW_MASK 0x03 /* bits per word/sample */
+#define CTRL_BPW_SHIFT 10
+#define PIC32_BPW_8 0
+#define PIC32_BPW_16 1
+#define PIC32_BPW_32 2
+#define CTRL_SIDL BIT(13) /* sleep when idle */
+#define CTRL_ON BIT(15) /* enable macro */
+#define CTRL_ENHBUF BIT(16) /* enable enhanced buffering */
+#define CTRL_MCLKSEL BIT(23) /* select clock source */
+#define CTRL_MSSEN BIT(28) /* macro driven /SS */
+#define CTRL_FRMEN BIT(31) /* enable framing mode */
+
+/* Bit fields of SPI Status Register */
+#define STAT_RF_EMPTY BIT(5) /* RX Fifo empty */
+#define STAT_RX_OV BIT(6) /* err, s/w needs to clear */
+#define STAT_TX_UR BIT(8) /* UR in Framed SPI modes */
+#define STAT_FRM_ERR BIT(12) /* Multiple Frame Sync pulse */
+#define STAT_TF_LVL_MASK 0x1F
+#define STAT_TF_LVL_SHIFT 16
+#define STAT_RF_LVL_MASK 0x1F
+#define STAT_RF_LVL_SHIFT 24
+
+/* Bit fields of SPI Baud Register */
+#define BAUD_MASK 0x1ff
+
+/* Bit fields of SPI Control2 Register */
+#define CTRL2_TX_UR_EN BIT(10) /* Enable int on Tx under-run */
+#define CTRL2_RX_OV_EN BIT(11) /* Enable int on Rx over-run */
+#define CTRL2_FRM_ERR_EN BIT(12) /* Enable frame err int */
+
+/* Minimum DMA transfer size */
+#define PIC32_DMA_LEN_MIN 64
+
+struct pic32_spi {
+ dma_addr_t dma_base;
+ struct pic32_spi_regs __iomem *regs;
+ int fault_irq;
+ int rx_irq;
+ int tx_irq;
+ u32 fifo_n_byte; /* FIFO depth in bytes */
+ struct clk *clk;
+ struct spi_master *master;
+ /* Current controller setting */
+ u32 speed_hz; /* spi-clk rate */
+ u32 mode;
+ u32 bits_per_word;
+ u32 fifo_n_elm; /* FIFO depth in words */
+#define PIC32F_DMA_PREP 0 /* DMA chnls configured */
+ unsigned long flags;
+ /* Current transfer state */
+ struct completion xfer_done;
+ /* PIO transfer specific */
+ const void *tx;
+ const void *tx_end;
+ const void *rx;
+ const void *rx_end;
+ int len;
+ void (*rx_fifo)(struct pic32_spi *);
+ void (*tx_fifo)(struct pic32_spi *);
+};
+
+static inline void pic32_spi_enable(struct pic32_spi *pic32s)
+{
+ writel(CTRL_ON | CTRL_SIDL, &pic32s->regs->ctrl_set);
+}
+
+static inline void pic32_spi_disable(struct pic32_spi *pic32s)
+{
+ writel(CTRL_ON | CTRL_SIDL, &pic32s->regs->ctrl_clr);
+
+ /* avoid SPI registers read/write at immediate next CPU clock */
+ ndelay(20);
+}
+
+static void pic32_spi_set_clk_rate(struct pic32_spi *pic32s, u32 spi_ck)
+{
+ u32 div;
+
+ /* div = (clk_in / 2 * spi_ck) - 1 */
+ div = DIV_ROUND_CLOSEST(clk_get_rate(pic32s->clk), 2 * spi_ck) - 1;
+
+ writel(div & BAUD_MASK, &pic32s->regs->baud);
+}
+
+static inline u32 pic32_rx_fifo_level(struct pic32_spi *pic32s)
+{
+ u32 sr = readl(&pic32s->regs->status);
+
+ return (sr >> STAT_RF_LVL_SHIFT) & STAT_RF_LVL_MASK;
+}
+
+static inline u32 pic32_tx_fifo_level(struct pic32_spi *pic32s)
+{
+ u32 sr = readl(&pic32s->regs->status);
+
+ return (sr >> STAT_TF_LVL_SHIFT) & STAT_TF_LVL_MASK;
+}
+
+/* Return the max entries we can fill into tx fifo */
+static u32 pic32_tx_max(struct pic32_spi *pic32s, int n_bytes)
+{
+ u32 tx_left, tx_room, rxtx_gap;
+
+ tx_left = (pic32s->tx_end - pic32s->tx) / n_bytes;
+ tx_room = pic32s->fifo_n_elm - pic32_tx_fifo_level(pic32s);
+
+ /*
+ * Another concern is about the tx/rx mismatch, we
+ * though to use (pic32s->fifo_n_byte - rxfl - txfl) as
+ * one maximum value for tx, but it doesn't cover the
+ * data which is out of tx/rx fifo and inside the
+ * shift registers. So a ctrl from sw point of
+ * view is taken.
+ */
+ rxtx_gap = ((pic32s->rx_end - pic32s->rx) -
+ (pic32s->tx_end - pic32s->tx)) / n_bytes;
+ return min3(tx_left, tx_room, (u32)(pic32s->fifo_n_elm - rxtx_gap));
+}
+
+/* Return the max entries we should read out of rx fifo */
+static u32 pic32_rx_max(struct pic32_spi *pic32s, int n_bytes)
+{
+ u32 rx_left = (pic32s->rx_end - pic32s->rx) / n_bytes;
+
+ return min_t(u32, rx_left, pic32_rx_fifo_level(pic32s));
+}
+
+#define BUILD_SPI_FIFO_RW(__name, __type, __bwl) \
+static void pic32_spi_rx_##__name(struct pic32_spi *pic32s) \
+{ \
+ __type v; \
+ u32 mx = pic32_rx_max(pic32s, sizeof(__type)); \
+ for (; mx; mx--) { \
+ v = read##__bwl(&pic32s->regs->buf); \
+ if (pic32s->rx_end - pic32s->len) \
+ *(__type *)(pic32s->rx) = v; \
+ pic32s->rx += sizeof(__type); \
+ } \
+} \
+ \
+static void pic32_spi_tx_##__name(struct pic32_spi *pic32s) \
+{ \
+ __type v; \
+ u32 mx = pic32_tx_max(pic32s, sizeof(__type)); \
+ for (; mx ; mx--) { \
+ v = (__type)~0U; \
+ if (pic32s->tx_end - pic32s->len) \
+ v = *(__type *)(pic32s->tx); \
+ write##__bwl(v, &pic32s->regs->buf); \
+ pic32s->tx += sizeof(__type); \
+ } \
+}
+
+BUILD_SPI_FIFO_RW(byte, u8, b);
+BUILD_SPI_FIFO_RW(word, u16, w);
+BUILD_SPI_FIFO_RW(dword, u32, l);
+
+static void pic32_err_stop(struct pic32_spi *pic32s, const char *msg)
+{
+ /* disable all interrupts */
+ disable_irq_nosync(pic32s->fault_irq);
+ disable_irq_nosync(pic32s->rx_irq);
+ disable_irq_nosync(pic32s->tx_irq);
+
+ /* Show err message and abort xfer with err */
+ dev_err(&pic32s->master->dev, "%s\n", msg);
+ if (pic32s->master->cur_msg)
+ pic32s->master->cur_msg->status = -EIO;
+ complete(&pic32s->xfer_done);
+}
+
+static irqreturn_t pic32_spi_fault_irq(int irq, void *dev_id)
+{
+ struct pic32_spi *pic32s = dev_id;
+ u32 status;
+
+ status = readl(&pic32s->regs->status);
+
+ /* Error handling */
+ if (status & (STAT_RX_OV | STAT_TX_UR)) {
+ writel(STAT_RX_OV, &pic32s->regs->status_clr);
+ writel(STAT_TX_UR, &pic32s->regs->status_clr);
+ pic32_err_stop(pic32s, "err_irq: fifo ov/ur-run\n");
+ return IRQ_HANDLED;
+ }
+
+ if (status & STAT_FRM_ERR) {
+ pic32_err_stop(pic32s, "err_irq: frame error");
+ return IRQ_HANDLED;
+ }
+
+ if (!pic32s->master->cur_msg) {
+ pic32_err_stop(pic32s, "err_irq: no mesg");
+ return IRQ_NONE;
+ }
+
+ return IRQ_NONE;
+}
+
+static irqreturn_t pic32_spi_rx_irq(int irq, void *dev_id)
+{
+ struct pic32_spi *pic32s = dev_id;
+
+ pic32s->rx_fifo(pic32s);
+
+ /* rx complete ? */
+ if (pic32s->rx_end == pic32s->rx) {
+ /* disable all interrupts */
+ disable_irq_nosync(pic32s->fault_irq);
+ disable_irq_nosync(pic32s->rx_irq);
+
+ /* complete current xfer */
+ complete(&pic32s->xfer_done);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t pic32_spi_tx_irq(int irq, void *dev_id)
+{
+ struct pic32_spi *pic32s = dev_id;
+
+ pic32s->tx_fifo(pic32s);
+
+ /* tx complete? disable tx interrupt */
+ if (pic32s->tx_end == pic32s->tx)
+ disable_irq_nosync(pic32s->tx_irq);
+
+ return IRQ_HANDLED;
+}
+
+static void pic32_spi_dma_rx_notify(void *data)
+{
+ struct pic32_spi *pic32s = data;
+
+ complete(&pic32s->xfer_done);
+}
+
+static int pic32_spi_dma_transfer(struct pic32_spi *pic32s,
+ struct spi_transfer *xfer)
+{
+ struct spi_master *master = pic32s->master;
+ struct dma_async_tx_descriptor *desc_rx;
+ struct dma_async_tx_descriptor *desc_tx;
+ dma_cookie_t cookie;
+ int ret;
+
+ if (!master->dma_rx || !master->dma_tx)
+ return -ENODEV;
+
+ desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
+ xfer->rx_sg.sgl,
+ xfer->rx_sg.nents,
+ DMA_FROM_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc_rx) {
+ ret = -EINVAL;
+ goto err_dma;
+ }
+
+ desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
+ xfer->tx_sg.sgl,
+ xfer->tx_sg.nents,
+ DMA_TO_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc_tx) {
+ ret = -EINVAL;
+ goto err_dma;
+ }
+
+ /* Put callback on the RX transfer, that should finish last */
+ desc_rx->callback = pic32_spi_dma_rx_notify;
+ desc_rx->callback_param = pic32s;
+
+ cookie = dmaengine_submit(desc_rx);
+ ret = dma_submit_error(cookie);
+ if (ret)
+ goto err_dma;
+
+ cookie = dmaengine_submit(desc_tx);
+ ret = dma_submit_error(cookie);
+ if (ret)
+ goto err_dma_tx;
+
+ dma_async_issue_pending(master->dma_rx);
+ dma_async_issue_pending(master->dma_tx);
+
+ return 0;
+
+err_dma_tx:
+ dmaengine_terminate_all(master->dma_rx);
+err_dma:
+ return ret;
+}
+
+static int pic32_spi_dma_config(struct pic32_spi *pic32s, u32 dma_width)
+{
+ int buf_offset = offsetof(struct pic32_spi_regs, buf);
+ struct spi_master *master = pic32s->master;
+ struct dma_slave_config cfg;
+ int ret;
+
+ cfg.device_fc = true;
+ cfg.src_addr = pic32s->dma_base + buf_offset;
+ cfg.dst_addr = pic32s->dma_base + buf_offset;
+ cfg.src_maxburst = pic32s->fifo_n_elm / 2; /* fill one-half */
+ cfg.dst_maxburst = pic32s->fifo_n_elm / 2; /* drain one-half */
+ cfg.src_addr_width = dma_width;
+ cfg.dst_addr_width = dma_width;
+ /* tx channel */
+ cfg.slave_id = pic32s->tx_irq;
+ cfg.direction = DMA_MEM_TO_DEV;
+ ret = dmaengine_slave_config(master->dma_tx, &cfg);
+ if (ret) {
+ dev_err(&master->dev, "tx channel setup failed\n");
+ return ret;
+ }
+ /* rx channel */
+ cfg.slave_id = pic32s->rx_irq;
+ cfg.direction = DMA_DEV_TO_MEM;
+ ret = dmaengine_slave_config(master->dma_rx, &cfg);
+ if (ret)
+ dev_err(&master->dev, "rx channel setup failed\n");
+
+ return ret;
+}
+
+static int pic32_spi_set_word_size(struct pic32_spi *pic32s, u8 bits_per_word)
+{
+ enum dma_slave_buswidth dmawidth;
+ u32 buswidth, v;
+
+ switch (bits_per_word) {
+ case 8:
+ pic32s->rx_fifo = pic32_spi_rx_byte;
+ pic32s->tx_fifo = pic32_spi_tx_byte;
+ buswidth = PIC32_BPW_8;
+ dmawidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ break;
+ case 16:
+ pic32s->rx_fifo = pic32_spi_rx_word;
+ pic32s->tx_fifo = pic32_spi_tx_word;
+ buswidth = PIC32_BPW_16;
+ dmawidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+ break;
+ case 32:
+ pic32s->rx_fifo = pic32_spi_rx_dword;
+ pic32s->tx_fifo = pic32_spi_tx_dword;
+ buswidth = PIC32_BPW_32;
+ dmawidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ break;
+ default:
+ /* not supported */
+ return -EINVAL;
+ }
+
+ /* calculate maximum number of words fifos can hold */
+ pic32s->fifo_n_elm = DIV_ROUND_UP(pic32s->fifo_n_byte,
+ bits_per_word / 8);
+ /* set word size */
+ v = readl(&pic32s->regs->ctrl);
+ v &= ~(CTRL_BPW_MASK << CTRL_BPW_SHIFT);
+ v |= buswidth << CTRL_BPW_SHIFT;
+ writel(v, &pic32s->regs->ctrl);
+
+ /* re-configure dma width, if required */
+ if (test_bit(PIC32F_DMA_PREP, &pic32s->flags))
+ pic32_spi_dma_config(pic32s, dmawidth);
+
+ return 0;
+}
+
+static int pic32_spi_prepare_hardware(struct spi_master *master)
+{
+ struct pic32_spi *pic32s = spi_master_get_devdata(master);
+
+ pic32_spi_enable(pic32s);
+
+ return 0;
+}
+
+static int pic32_spi_prepare_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct pic32_spi *pic32s = spi_master_get_devdata(master);
+ struct spi_device *spi = msg->spi;
+ u32 val;
+
+ /* set device specific bits_per_word */
+ if (pic32s->bits_per_word != spi->bits_per_word) {
+ pic32_spi_set_word_size(pic32s, spi->bits_per_word);
+ pic32s->bits_per_word = spi->bits_per_word;
+ }
+
+ /* device specific speed change */
+ if (pic32s->speed_hz != spi->max_speed_hz) {
+ pic32_spi_set_clk_rate(pic32s, spi->max_speed_hz);
+ pic32s->speed_hz = spi->max_speed_hz;
+ }
+
+ /* device specific mode change */
+ if (pic32s->mode != spi->mode) {
+ val = readl(&pic32s->regs->ctrl);
+ /* active low */
+ if (spi->mode & SPI_CPOL)
+ val |= CTRL_CKP;
+ else
+ val &= ~CTRL_CKP;
+ /* tx on rising edge */
+ if (spi->mode & SPI_CPHA)
+ val &= ~CTRL_CKE;
+ else
+ val |= CTRL_CKE;
+
+ /* rx at end of tx */
+ val |= CTRL_SMP;
+ writel(val, &pic32s->regs->ctrl);
+ pic32s->mode = spi->mode;
+ }
+
+ return 0;
+}
+
+static bool pic32_spi_can_dma(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct pic32_spi *pic32s = spi_master_get_devdata(master);
+
+ /* skip using DMA on small size transfer to avoid overhead.*/
+ return (xfer->len >= PIC32_DMA_LEN_MIN) &&
+ test_bit(PIC32F_DMA_PREP, &pic32s->flags);
+}
+
+static int pic32_spi_one_transfer(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *transfer)
+{
+ struct pic32_spi *pic32s;
+ bool dma_issued = false;
+ int ret;
+
+ pic32s = spi_master_get_devdata(master);
+
+ /* handle transfer specific word size change */
+ if (transfer->bits_per_word &&
+ (transfer->bits_per_word != pic32s->bits_per_word)) {
+ ret = pic32_spi_set_word_size(pic32s, transfer->bits_per_word);
+ if (ret)
+ return ret;
+ pic32s->bits_per_word = transfer->bits_per_word;
+ }
+
+ /* handle transfer specific speed change */
+ if (transfer->speed_hz && (transfer->speed_hz != pic32s->speed_hz)) {
+ pic32_spi_set_clk_rate(pic32s, transfer->speed_hz);
+ pic32s->speed_hz = transfer->speed_hz;
+ }
+
+ reinit_completion(&pic32s->xfer_done);
+
+ /* transact by DMA mode */
+ if (transfer->rx_sg.nents && transfer->tx_sg.nents) {
+ ret = pic32_spi_dma_transfer(pic32s, transfer);
+ if (ret) {
+ dev_err(&spi->dev, "dma submit error\n");
+ return ret;
+ }
+
+ /* DMA issued */
+ dma_issued = true;
+ } else {
+ /* set current transfer information */
+ pic32s->tx = (const void *)transfer->tx_buf;
+ pic32s->rx = (const void *)transfer->rx_buf;
+ pic32s->tx_end = pic32s->tx + transfer->len;
+ pic32s->rx_end = pic32s->rx + transfer->len;
+ pic32s->len = transfer->len;
+
+ /* transact by interrupt driven PIO */
+ enable_irq(pic32s->fault_irq);
+ enable_irq(pic32s->rx_irq);
+ enable_irq(pic32s->tx_irq);
+ }
+
+ /* wait for completion */
+ ret = wait_for_completion_timeout(&pic32s->xfer_done, 2 * HZ);
+ if (ret <= 0) {
+ dev_err(&spi->dev, "wait error/timedout\n");
+ if (dma_issued) {
+ dmaengine_terminate_all(master->dma_rx);
+ dmaengine_terminate_all(master->dma_rx);
+ }
+ ret = -ETIMEDOUT;
+ } else {
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static int pic32_spi_unprepare_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ /* nothing to do */
+ return 0;
+}
+
+static int pic32_spi_unprepare_hardware(struct spi_master *master)
+{
+ struct pic32_spi *pic32s = spi_master_get_devdata(master);
+
+ pic32_spi_disable(pic32s);
+
+ return 0;
+}
+
+/* This may be called multiple times by same spi dev */
+static int pic32_spi_setup(struct spi_device *spi)
+{
+ if (!spi->max_speed_hz) {
+ dev_err(&spi->dev, "No max speed HZ parameter\n");
+ return -EINVAL;
+ }
+
+ /* PIC32 spi controller can drive /CS during transfer depending
+ * on tx fifo fill-level. /CS will stay asserted as long as TX
+ * fifo is non-empty, else will be deasserted indicating
+ * completion of the ongoing transfer. This might result into
+ * unreliable/erroneous SPI transactions.
+ * To avoid that we will always handle /CS by toggling GPIO.
+ */
+ if (!gpio_is_valid(spi->cs_gpio))
+ return -EINVAL;
+
+ gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
+
+ return 0;
+}
+
+static void pic32_spi_cleanup(struct spi_device *spi)
+{
+ /* de-activate cs-gpio */
+ gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
+}
+
+static void pic32_spi_dma_prep(struct pic32_spi *pic32s, struct device *dev)
+{
+ struct spi_master *master = pic32s->master;
+ dma_cap_mask_t mask;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ master->dma_rx = dma_request_slave_channel_compat(mask, NULL, NULL,
+ dev, "spi-rx");
+ if (!master->dma_rx) {
+ dev_warn(dev, "RX channel not found.\n");
+ goto out_err;
+ }
+
+ master->dma_tx = dma_request_slave_channel_compat(mask, NULL, NULL,
+ dev, "spi-tx");
+ if (!master->dma_tx) {
+ dev_warn(dev, "TX channel not found.\n");
+ goto out_err;
+ }
+
+ if (pic32_spi_dma_config(pic32s, DMA_SLAVE_BUSWIDTH_1_BYTE))
+ goto out_err;
+
+ /* DMA chnls allocated and prepared */
+ set_bit(PIC32F_DMA_PREP, &pic32s->flags);
+
+ return;
+
+out_err:
+ if (master->dma_rx)
+ dma_release_channel(master->dma_rx);
+
+ if (master->dma_tx)
+ dma_release_channel(master->dma_tx);
+}
+
+static void pic32_spi_dma_unprep(struct pic32_spi *pic32s)
+{
+ if (!test_bit(PIC32F_DMA_PREP, &pic32s->flags))
+ return;
+
+ clear_bit(PIC32F_DMA_PREP, &pic32s->flags);
+ if (pic32s->master->dma_rx)
+ dma_release_channel(pic32s->master->dma_rx);
+
+ if (pic32s->master->dma_tx)
+ dma_release_channel(pic32s->master->dma_tx);
+}
+
+static void pic32_spi_hw_init(struct pic32_spi *pic32s)
+{
+ u32 ctrl;
+
+ /* disable hardware */
+ pic32_spi_disable(pic32s);
+
+ ctrl = readl(&pic32s->regs->ctrl);
+ /* enable enhanced fifo of 128bit deep */
+ ctrl |= CTRL_ENHBUF;
+ pic32s->fifo_n_byte = 16;
+
+ /* disable framing mode */
+ ctrl &= ~CTRL_FRMEN;
+
+ /* enable master mode while disabled */
+ ctrl |= CTRL_MSTEN;
+
+ /* set tx fifo threshold interrupt */
+ ctrl &= ~(0x3 << CTRL_TX_INT_SHIFT);
+ ctrl |= (TX_FIFO_HALF_EMPTY << CTRL_TX_INT_SHIFT);
+
+ /* set rx fifo threshold interrupt */
+ ctrl &= ~(0x3 << CTRL_RX_INT_SHIFT);
+ ctrl |= (RX_FIFO_NOT_EMPTY << CTRL_RX_INT_SHIFT);
+
+ /* select clk source */
+ ctrl &= ~CTRL_MCLKSEL;
+
+ /* set manual /CS mode */
+ ctrl &= ~CTRL_MSSEN;
+
+ writel(ctrl, &pic32s->regs->ctrl);
+
+ /* enable error reporting */
+ ctrl = CTRL2_TX_UR_EN | CTRL2_RX_OV_EN | CTRL2_FRM_ERR_EN;
+ writel(ctrl, &pic32s->regs->ctrl2_set);
+}
+
+static int pic32_spi_hw_probe(struct platform_device *pdev,
+ struct pic32_spi *pic32s)
+{
+ struct resource *mem;
+ int ret;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pic32s->regs = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(pic32s->regs))
+ return PTR_ERR(pic32s->regs);
+
+ pic32s->dma_base = mem->start;
+
+ /* get irq resources: err-irq, rx-irq, tx-irq */
+ pic32s->fault_irq = platform_get_irq_byname(pdev, "fault");
+ if (pic32s->fault_irq < 0) {
+ dev_err(&pdev->dev, "fault-irq not found\n");
+ return pic32s->fault_irq;
+ }
+
+ pic32s->rx_irq = platform_get_irq_byname(pdev, "rx");
+ if (pic32s->rx_irq < 0) {
+ dev_err(&pdev->dev, "rx-irq not found\n");
+ return pic32s->rx_irq;
+ }
+
+ pic32s->tx_irq = platform_get_irq_byname(pdev, "tx");
+ if (pic32s->tx_irq < 0) {
+ dev_err(&pdev->dev, "tx-irq not found\n");
+ return pic32s->tx_irq;
+ }
+
+ /* get clock */
+ pic32s->clk = devm_clk_get(&pdev->dev, "mck0");
+ if (IS_ERR(pic32s->clk)) {
+ dev_err(&pdev->dev, "clk not found\n");
+ ret = PTR_ERR(pic32s->clk);
+ goto err_unmap_mem;
+ }
+
+ ret = clk_prepare_enable(pic32s->clk);
+ if (ret)
+ goto err_unmap_mem;
+
+ pic32_spi_hw_init(pic32s);
+
+ return 0;
+
+err_unmap_mem:
+ dev_err(&pdev->dev, "%s failed, err %d\n", __func__, ret);
+ return ret;
+}
+
+static int pic32_spi_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct pic32_spi *pic32s;
+ int ret;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*pic32s));
+ if (!master)
+ return -ENOMEM;
+
+ pic32s = spi_master_get_devdata(master);
+ pic32s->master = master;
+
+ ret = pic32_spi_hw_probe(pdev, pic32s);
+ if (ret)
+ goto err_master;
+
+ master->dev.of_node = of_node_get(pdev->dev.of_node);
+ master->mode_bits = SPI_MODE_3 | SPI_MODE_0 | SPI_CS_HIGH;
+ master->num_chipselect = 1; /* single chip-select */
+ master->max_speed_hz = clk_get_rate(pic32s->clk);
+ master->setup = pic32_spi_setup;
+ master->cleanup = pic32_spi_cleanup;
+ master->flags = SPI_MASTER_MUST_TX | SPI_MASTER_MUST_RX;
+ master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16) |
+ SPI_BPW_MASK(32);
+ master->transfer_one = pic32_spi_one_transfer;
+ master->prepare_message = pic32_spi_prepare_message;
+ master->unprepare_message = pic32_spi_unprepare_message;
+ master->prepare_transfer_hardware = pic32_spi_prepare_hardware;
+ master->unprepare_transfer_hardware = pic32_spi_unprepare_hardware;
+
+ /* optional DMA support */
+ pic32_spi_dma_prep(pic32s, &pdev->dev);
+ if (test_bit(PIC32F_DMA_PREP, &pic32s->flags))
+ master->can_dma = pic32_spi_can_dma;
+
+ init_completion(&pic32s->xfer_done);
+ pic32s->mode = -1;
+
+ /* install irq handlers (with irq-disabled) */
+ irq_set_status_flags(pic32s->fault_irq, IRQ_NOAUTOEN);
+ ret = devm_request_irq(&pdev->dev, pic32s->fault_irq,
+ pic32_spi_fault_irq, IRQF_NO_THREAD,
+ dev_name(&pdev->dev), pic32s);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "request fault-irq %d\n", pic32s->rx_irq);
+ goto err_bailout;
+ }
+
+ /* receive interrupt handler */
+ irq_set_status_flags(pic32s->rx_irq, IRQ_NOAUTOEN);
+ ret = devm_request_irq(&pdev->dev, pic32s->rx_irq,
+ pic32_spi_rx_irq, IRQF_NO_THREAD,
+ dev_name(&pdev->dev), pic32s);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "request rx-irq %d\n", pic32s->rx_irq);
+ goto err_bailout;
+ }
+
+ /* transmit interrupt handler */
+ irq_set_status_flags(pic32s->tx_irq, IRQ_NOAUTOEN);
+ ret = devm_request_irq(&pdev->dev, pic32s->tx_irq,
+ pic32_spi_tx_irq, IRQF_NO_THREAD,
+ dev_name(&pdev->dev), pic32s);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "request tx-irq %d\n", pic32s->tx_irq);
+ goto err_bailout;
+ }
+
+ /* register master */
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (ret) {
+ dev_err(&master->dev, "failed registering spi master\n");
+ goto err_bailout;
+ }
+
+ platform_set_drvdata(pdev, pic32s);
+
+ return 0;
+
+err_bailout:
+ clk_disable_unprepare(pic32s->clk);
+err_master:
+ spi_master_put(master);
+ return ret;
+}
+
+static int pic32_spi_remove(struct platform_device *pdev)
+{
+ struct pic32_spi *pic32s;
+
+ pic32s = platform_get_drvdata(pdev);
+ pic32_spi_disable(pic32s);
+ clk_disable_unprepare(pic32s->clk);
+ pic32_spi_dma_unprep(pic32s);
+
+ return 0;
+}
+
+static const struct of_device_id pic32_spi_of_match[] = {
+ {.compatible = "microchip,pic32mzda-spi",},
+ {},
+};
+MODULE_DEVICE_TABLE(of, pic32_spi_of_match);
+
+static struct platform_driver pic32_spi_driver = {
+ .driver = {
+ .name = "spi-pic32",
+ .of_match_table = of_match_ptr(pic32_spi_of_match),
+ },
+ .probe = pic32_spi_probe,
+ .remove = pic32_spi_remove,
+};
+
+module_platform_driver(pic32_spi_driver);
+
+MODULE_AUTHOR("Purna Chandra Mandal <purna.mandal@microchip.com>");
+MODULE_DESCRIPTION("Microchip SPI driver for PIC32 SPI controller.");
+MODULE_LICENSE("GPL v2");
projects / cascardo / linux.git / commitdiff