drivers/i2c/busses/i2c-designware-platdrv.c

   1 /*
   2  * Synopsys DesignWare I2C adapter driver (master only).
   3  *
   4  * Based on the TI DAVINCI I2C adapter driver.
   5  *
   6  * Copyright (C) 2006 Texas Instruments.
   7  * Copyright (C) 2007 MontaVista Software Inc.
   8  * Copyright (C) 2009 Provigent Ltd.
   9  *
  10  * ----------------------------------------------------------------------------
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  * ----------------------------------------------------------------------------
  22  *
  23  */
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/delay.h>
  27 #include <linux/i2c.h>
  28 #include <linux/clk.h>
  29 #include <linux/errno.h>
  30 #include <linux/sched.h>
  31 #include <linux/err.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/of.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/pm.h>
  36 #include <linux/pm_runtime.h>
  37 #include <linux/io.h>
  38 #include <linux/slab.h>
  39 #include <linux/acpi.h>
  40 #include "i2c-designware-core.h"
  41
  42 static struct i2c_algorithm i2c_dw_algo = {
  43         .master_xfer    = i2c_dw_xfer,
  44         .functionality  = i2c_dw_func,
  45 };
  46 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  47 {
  48         return clk_get_rate(dev->clk)/1000;
  49 }
  50
  51 #ifdef CONFIG_ACPI
  52 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
  53                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
  54 {
  55         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  56         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
  57         union acpi_object *obj;
  58
  59         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
  60                 return;
  61
  62         obj = (union acpi_object *)buf.pointer;
  63         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
  64                 const union acpi_object *objs = obj->package.elements;
  65
  66                 *hcnt = (u16)objs[0].integer.value;
  67                 *lcnt = (u16)objs[1].integer.value;
  68                 if (sda_hold)
  69                         *sda_hold = (u32)objs[2].integer.value;
  70         }
  71
  72         kfree(buf.pointer);
  73 }
  74
  75 static int dw_i2c_acpi_configure(struct platform_device *pdev)
  76 {
  77         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  78         bool fs_mode = dev->master_cfg & DW_IC_CON_SPEED_FAST;
  79
  80         if (!ACPI_HANDLE(&pdev->dev))
  81                 return -ENODEV;
  82
  83         dev->adapter.nr = -1;
  84         dev->tx_fifo_depth = 32;
  85         dev->rx_fifo_depth = 32;
  86
  87         /*
  88          * Try to get SDA hold time and *CNT values from an ACPI method if
  89          * it exists for both supported speed modes.
  90          */
  91         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt,
  92                            fs_mode ? NULL : &dev->sda_hold_time);
  93         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
  94                            fs_mode ? &dev->sda_hold_time : NULL);
  95
  96         return 0;
  97 }
  98
  99 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 100         { "INT33C2", 0 },
 101         { "INT33C3", 0 },
 102         { "INT3432", 0 },
 103         { "INT3433", 0 },
 104         { "80860F41", 0 },
 105         { }
 106 };
 107 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 108 #else
 109 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 110 {
 111         return -ENODEV;
 112 }
 113 #endif
 114
 115 static int dw_i2c_probe(struct platform_device *pdev)
 116 {
 117         struct dw_i2c_dev *dev;
 118         struct i2c_adapter *adap;
 119         struct resource *mem;
 120         int irq, r;
 121
 122         irq = platform_get_irq(pdev, 0);
 123         if (irq < 0) {
 124                 dev_err(&pdev->dev, "no irq resource?\n");
 125                 return irq; /* -ENXIO */
 126         }
 127
 128         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
 129         if (!dev)
 130                 return -ENOMEM;
 131
 132         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 133         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 134         if (IS_ERR(dev->base))
 135                 return PTR_ERR(dev->base);
 136
 137         init_completion(&dev->cmd_complete);
 138         mutex_init(&dev->lock);
 139         dev->dev = &pdev->dev;
 140         dev->irq = irq;
 141         platform_set_drvdata(pdev, dev);
 142
 143         dev->clk = devm_clk_get(&pdev->dev, NULL);
 144         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 145
 146         if (IS_ERR(dev->clk))
 147                 return PTR_ERR(dev->clk);
 148         clk_prepare_enable(dev->clk);
 149
 150         if (pdev->dev.of_node) {
 151                 u32 ht = 0;
 152                 u32 ic_clk = dev->get_clk_rate_khz(dev);
 153
 154                 of_property_read_u32(pdev->dev.of_node,
 155                                         "i2c-sda-hold-time-ns", &ht);
 156                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
 157                                              1000000);
 158         }
 159
 160         dev->functionality =
 161                 I2C_FUNC_I2C |
 162                 I2C_FUNC_10BIT_ADDR |
 163                 I2C_FUNC_SMBUS_BYTE |
 164                 I2C_FUNC_SMBUS_BYTE_DATA |
 165                 I2C_FUNC_SMBUS_WORD_DATA |
 166                 I2C_FUNC_SMBUS_I2C_BLOCK;
 167         dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 168                 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 169
 170         /* Try first if we can configure the device from ACPI */
 171         r = dw_i2c_acpi_configure(pdev);
 172         if (r) {
 173                 u32 param1 = i2c_dw_read_comp_param(dev);
 174
 175                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
 176                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
 177                 dev->adapter.nr = pdev->id;
 178         }
 179         r = i2c_dw_init(dev);
 180         if (r)
 181                 return r;
 182
 183         i2c_dw_disable_int(dev);
 184         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
 185                         pdev->name, dev);
 186         if (r) {
 187                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
 188                 return r;
 189         }
 190
 191         adap = &dev->adapter;
 192         i2c_set_adapdata(adap, dev);
 193         adap->owner = THIS_MODULE;
 194         adap->class = I2C_CLASS_HWMON;
 195         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
 196                         sizeof(adap->name));
 197         adap->algo = &i2c_dw_algo;
 198         adap->dev.parent = &pdev->dev;
 199         adap->dev.of_node = pdev->dev.of_node;
 200
 201         r = i2c_add_numbered_adapter(adap);
 202         if (r) {
 203                 dev_err(&pdev->dev, "failure adding adapter\n");
 204                 return r;
 205         }
 206
 207         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 208         pm_runtime_use_autosuspend(&pdev->dev);
 209         pm_runtime_set_active(&pdev->dev);
 210         pm_runtime_enable(&pdev->dev);
 211
 212         return 0;
 213 }
 214
 215 static int dw_i2c_remove(struct platform_device *pdev)
 216 {
 217         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 218
 219         pm_runtime_get_sync(&pdev->dev);
 220
 221         i2c_del_adapter(&dev->adapter);
 222
 223         i2c_dw_disable(dev);
 224
 225         pm_runtime_put(&pdev->dev);
 226         pm_runtime_disable(&pdev->dev);
 227
 228         return 0;
 229 }
 230
 231 #ifdef CONFIG_OF
 232 static const struct of_device_id dw_i2c_of_match[] = {
 233         { .compatible = "snps,designware-i2c", },
 234         {},
 235 };
 236 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 237 #endif
 238
 239 #ifdef CONFIG_PM_SLEEP
 240 static int dw_i2c_suspend(struct device *dev)
 241 {
 242         struct platform_device *pdev = to_platform_device(dev);
 243         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 244
 245         clk_disable_unprepare(i_dev->clk);
 246
 247         return 0;
 248 }
 249
 250 static int dw_i2c_resume(struct device *dev)
 251 {
 252         struct platform_device *pdev = to_platform_device(dev);
 253         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 254
 255         clk_prepare_enable(i_dev->clk);
 256         i2c_dw_init(i_dev);
 257
 258         return 0;
 259 }
 260
 261 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
 262 #define DW_I2C_DEV_PM_OPS       (&dw_i2c_dev_pm_ops)
 263 #else
 264 #define DW_I2C_DEV_PM_OPS       NULL
 265 #endif
 266
 267 /* work with hotplug and coldplug */
 268 MODULE_ALIAS("platform:i2c_designware");
 269
 270 static struct platform_driver dw_i2c_driver = {
 271         .probe = dw_i2c_probe,
 272         .remove = dw_i2c_remove,
 273         .driver         = {
 274                 .name   = "i2c_designware",
 275                 .owner  = THIS_MODULE,
 276                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 277                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 278                 .pm     = DW_I2C_DEV_PM_OPS,
 279         },
 280 };
 281
 282 static int __init dw_i2c_init_driver(void)
 283 {
 284         return platform_driver_register(&dw_i2c_driver);
 285 }
 286 subsys_initcall(dw_i2c_init_driver);
 287
 288 static void __exit dw_i2c_exit_driver(void)
 289 {
 290         platform_driver_unregister(&dw_i2c_driver);
 291 }
 292 module_exit(dw_i2c_exit_driver);
 293
 294 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 295 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 296 MODULE_LICENSE("GPL");