drivers/i2c/busses/i2c-thunderx-pcidrv.c

   1 /*
   2  * Cavium ThunderX i2c driver.
   3  *
   4  * Copyright (C) 2015,2016 Cavium Inc.
   5  * Authors: Fred Martin <fmartin@caviumnetworks.com>
   6  *          Jan Glauber <jglauber@cavium.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2. This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/clk.h>
  15 #include <linux/delay.h>
  16 #include <linux/i2c.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/pci.h>
  21
  22 #include "i2c-octeon-core.h"
  23
  24 #define DRV_NAME "i2c-thunderx"
  25
  26 #define PCI_DEVICE_ID_THUNDER_TWSI      0xa012
  27
  28 #define SYS_FREQ_DEFAULT                700000000
  29
  30 #define TWSI_INT_ENA_W1C                0x1028
  31 #define TWSI_INT_ENA_W1S                0x1030
  32
  33 /*
  34  * Enable the CORE interrupt.
  35  * The interrupt will be asserted when there is non-STAT_IDLE state in the
  36  * SW_TWSI_EOP_TWSI_STAT register.
  37  */
  38 static void thunder_i2c_int_enable(struct octeon_i2c *i2c)
  39 {
  40         octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
  41                                 i2c->twsi_base + TWSI_INT_ENA_W1S);
  42 }
  43
  44 /*
  45  * Disable the CORE interrupt.
  46  */
  47 static void thunder_i2c_int_disable(struct octeon_i2c *i2c)
  48 {
  49         octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
  50                                 i2c->twsi_base + TWSI_INT_ENA_W1C);
  51 }
  52
  53 static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c)
  54 {
  55         octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
  56                                 i2c->twsi_base + TWSI_INT_ENA_W1S);
  57 }
  58
  59 static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c)
  60 {
  61         octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
  62                                 i2c->twsi_base + TWSI_INT_ENA_W1C);
  63 }
  64
  65 static u32 thunderx_i2c_functionality(struct i2c_adapter *adap)
  66 {
  67         return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
  68                I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
  69 }
  70
  71 static const struct i2c_algorithm thunderx_i2c_algo = {
  72         .master_xfer = octeon_i2c_xfer,
  73         .functionality = thunderx_i2c_functionality,
  74 };
  75
  76 static struct i2c_adapter thunderx_i2c_ops = {
  77         .owner  = THIS_MODULE,
  78         .name   = "ThunderX adapter",
  79         .algo   = &thunderx_i2c_algo,
  80 };
  81
  82 static void thunder_i2c_clock_enable(struct device *dev, struct octeon_i2c *i2c)
  83 {
  84         int ret;
  85
  86         i2c->clk = clk_get(dev, NULL);
  87         if (IS_ERR(i2c->clk)) {
  88                 i2c->clk = NULL;
  89                 goto skip;
  90         }
  91
  92         ret = clk_prepare_enable(i2c->clk);
  93         if (ret)
  94                 goto skip;
  95         i2c->sys_freq = clk_get_rate(i2c->clk);
  96
  97 skip:
  98         if (!i2c->sys_freq)
  99                 i2c->sys_freq = SYS_FREQ_DEFAULT;
 100 }
 101
 102 static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
 103 {
 104         if (!clk)
 105                 return;
 106         clk_disable_unprepare(clk);
 107         clk_put(clk);
 108 }
 109
 110 static int thunder_i2c_probe_pci(struct pci_dev *pdev,
 111                                  const struct pci_device_id *ent)
 112 {
 113         struct device *dev = &pdev->dev;
 114         struct octeon_i2c *i2c;
 115         int ret;
 116
 117         i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
 118         if (!i2c)
 119                 return -ENOMEM;
 120
 121         i2c->dev = dev;
 122         pci_set_drvdata(pdev, i2c);
 123         ret = pcim_enable_device(pdev);
 124         if (ret)
 125                 return ret;
 126
 127         ret = pci_request_regions(pdev, DRV_NAME);
 128         if (ret)
 129                 return ret;
 130
 131         i2c->twsi_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
 132         if (!i2c->twsi_base)
 133                 return -EINVAL;
 134
 135         thunder_i2c_clock_enable(dev, i2c);
 136         ret = device_property_read_u32(dev, "clock-frequency", &i2c->twsi_freq);
 137         if (ret)
 138                 i2c->twsi_freq = 100000;
 139
 140         init_waitqueue_head(&i2c->queue);
 141
 142         i2c->int_enable = thunder_i2c_int_enable;
 143         i2c->int_disable = thunder_i2c_int_disable;
 144         i2c->hlc_int_enable = thunder_i2c_hlc_int_enable;
 145         i2c->hlc_int_disable = thunder_i2c_hlc_int_disable;
 146
 147         ret = pci_enable_msix(pdev, &i2c->i2c_msix, 1);
 148         if (ret)
 149                 goto error;
 150
 151         ret = devm_request_irq(dev, i2c->i2c_msix.vector, octeon_i2c_isr, 0,
 152                                DRV_NAME, i2c);
 153         if (ret)
 154                 goto error;
 155
 156         ret = octeon_i2c_init_lowlevel(i2c);
 157         if (ret)
 158                 goto error;
 159
 160         octeon_i2c_set_clock(i2c);
 161
 162         i2c->adap = thunderx_i2c_ops;
 163         i2c->adap.retries = 5;
 164         i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
 165         i2c->adap.dev.parent = dev;
 166         i2c->adap.dev.of_node = pdev->dev.of_node;
 167         snprintf(i2c->adap.name, sizeof(i2c->adap.name),
 168                  "Cavium ThunderX i2c adapter at %s", dev_name(dev));
 169         i2c_set_adapdata(&i2c->adap, i2c);
 170
 171         ret = i2c_add_adapter(&i2c->adap);
 172         if (ret)
 173                 goto error;
 174
 175         dev_info(i2c->dev, "Probed. Set system clock to %u\n", i2c->sys_freq);
 176         return 0;
 177
 178 error:
 179         thunder_i2c_clock_disable(dev, i2c->clk);
 180         return ret;
 181 }
 182
 183 static void thunder_i2c_remove_pci(struct pci_dev *pdev)
 184 {
 185         struct octeon_i2c *i2c = pci_get_drvdata(pdev);
 186
 187         thunder_i2c_clock_disable(&pdev->dev, i2c->clk);
 188         i2c_del_adapter(&i2c->adap);
 189 }
 190
 191 static const struct pci_device_id thunder_i2c_pci_id_table[] = {
 192         { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_TWSI) },
 193         { 0, }
 194 };
 195
 196 MODULE_DEVICE_TABLE(pci, thunder_i2c_pci_id_table);
 197
 198 static struct pci_driver thunder_i2c_pci_driver = {
 199         .name           = DRV_NAME,
 200         .id_table       = thunder_i2c_pci_id_table,
 201         .probe          = thunder_i2c_probe_pci,
 202         .remove         = thunder_i2c_remove_pci,
 203 };
 204
 205 module_pci_driver(thunder_i2c_pci_driver);
 206
 207 MODULE_LICENSE("GPL");
 208 MODULE_AUTHOR("Fred Martin <fmartin@caviumnetworks.com>");
 209 MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC");