drivers/media/platform/exynos4-is/fimc-is-i2c.c

   1 /*
   2  * Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver
   3  *
   4  * Copyright (C) 2013 Samsung Electronics Co., Ltd.
   5  *
   6  * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/module.h>
  15 #include <linux/of_i2c.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/pm_runtime.h>
  18 #include <linux/slab.h>
  19 #include "fimc-is-i2c.h"
  20
  21 struct fimc_is_i2c {
  22         struct i2c_adapter adapter;
  23         struct clk *clock;
  24 };
  25
  26 /*
  27  * An empty algorithm is used as the actual I2C bus controller driver
  28  * is implemented in the FIMC-IS subsystem firmware and the host CPU
  29  * doesn't access the I2C bus controller.
  30  */
  31 static const struct i2c_algorithm fimc_is_i2c_algorithm;
  32
  33 static int fimc_is_i2c_probe(struct platform_device *pdev)
  34 {
  35         struct device_node *node = pdev->dev.of_node;
  36         struct fimc_is_i2c *isp_i2c;
  37         struct i2c_adapter *i2c_adap;
  38         int ret;
  39
  40         isp_i2c = devm_kzalloc(&pdev->dev, sizeof(*isp_i2c), GFP_KERNEL);
  41         if (!isp_i2c)
  42                 return -ENOMEM;
  43
  44         isp_i2c->clock = devm_clk_get(&pdev->dev, "i2c_isp");
  45         if (IS_ERR(isp_i2c->clock)) {
  46                 dev_err(&pdev->dev, "failed to get the clock\n");
  47                 return PTR_ERR(isp_i2c->clock);
  48         }
  49
  50         i2c_adap = &isp_i2c->adapter;
  51         i2c_adap->dev.of_node = node;
  52         i2c_adap->dev.parent = &pdev->dev;
  53         strlcpy(i2c_adap->name, "exynos4x12-isp-i2c", sizeof(i2c_adap->name));
  54         i2c_adap->owner = THIS_MODULE;
  55         i2c_adap->algo = &fimc_is_i2c_algorithm;
  56         i2c_adap->class = I2C_CLASS_SPD;
  57
  58         ret = i2c_add_adapter(i2c_adap);
  59         if (ret < 0) {
  60                 dev_err(&pdev->dev, "failed to add I2C bus %s\n",
  61                                                 node->full_name);
  62                 return ret;
  63         }
  64
  65         platform_set_drvdata(pdev, isp_i2c);
  66
  67         pm_runtime_enable(&pdev->dev);
  68         pm_runtime_enable(&i2c_adap->dev);
  69
  70         of_i2c_register_devices(i2c_adap);
  71
  72         return 0;
  73 }
  74
  75 static int fimc_is_i2c_remove(struct platform_device *pdev)
  76 {
  77         struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev);
  78
  79         pm_runtime_disable(&isp_i2c->adapter.dev);
  80         pm_runtime_disable(&pdev->dev);
  81         i2c_del_adapter(&isp_i2c->adapter);
  82
  83         return 0;
  84 }
  85
  86 static int fimc_is_i2c_suspend(struct device *dev)
  87 {
  88         struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
  89         clk_disable_unprepare(isp_i2c->clock);
  90         return 0;
  91 }
  92
  93 static int fimc_is_i2c_resume(struct device *dev)
  94 {
  95         struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
  96         return clk_prepare_enable(isp_i2c->clock);
  97 }
  98
  99 UNIVERSAL_DEV_PM_OPS(fimc_is_i2c_pm_ops, fimc_is_i2c_suspend,
 100                      fimc_is_i2c_resume, NULL);
 101
 102 static const struct of_device_id fimc_is_i2c_of_match[] = {
 103         { .compatible = FIMC_IS_I2C_COMPATIBLE },
 104         { },
 105 };
 106
 107 static struct platform_driver fimc_is_i2c_driver = {
 108         .probe          = fimc_is_i2c_probe,
 109         .remove         = fimc_is_i2c_remove,
 110         .driver = {
 111                 .of_match_table = fimc_is_i2c_of_match,
 112                 .name           = "fimc-isp-i2c",
 113                 .owner          = THIS_MODULE,
 114                 .pm             = &fimc_is_i2c_pm_ops,
 115         }
 116 };
 117
 118 int fimc_is_register_i2c_driver(void)
 119 {
 120         return platform_driver_register(&fimc_is_i2c_driver);
 121 }
 122
 123 void fimc_is_unregister_i2c_driver(void)
 124 {
 125         platform_driver_unregister(&fimc_is_i2c_driver);
 126 }