LXR linux/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/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
  21struct 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 */
  31static const struct i2c_algorithm fimc_is_i2c_algorithm;
  32
  33static 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        return 0;
  71}
  72
  73static int fimc_is_i2c_remove(struct platform_device *pdev)
  74{
  75        struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev);
  76
  77        pm_runtime_disable(&isp_i2c->adapter.dev);
  78        pm_runtime_disable(&pdev->dev);
  79        i2c_del_adapter(&isp_i2c->adapter);
  80
  81        return 0;
  82}
  83
  84static int fimc_is_i2c_suspend(struct device *dev)
  85{
  86        struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
  87        clk_disable_unprepare(isp_i2c->clock);
  88        return 0;
  89}
  90
  91static int fimc_is_i2c_resume(struct device *dev)
  92{
  93        struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
  94        return clk_prepare_enable(isp_i2c->clock);
  95}
  96
  97UNIVERSAL_DEV_PM_OPS(fimc_is_i2c_pm_ops, fimc_is_i2c_suspend,
  98                     fimc_is_i2c_resume, NULL);
  99
 100static const struct of_device_id fimc_is_i2c_of_match[] = {
 101        { .compatible = FIMC_IS_I2C_COMPATIBLE },
 102        { },
 103};
 104
 105static struct platform_driver fimc_is_i2c_driver = {
 106        .probe          = fimc_is_i2c_probe,
 107        .remove         = fimc_is_i2c_remove,
 108        .driver = {
 109                .of_match_table = fimc_is_i2c_of_match,
 110                .name           = "fimc-isp-i2c",
 111                .owner          = THIS_MODULE,
 112                .pm             = &fimc_is_i2c_pm_ops,
 113        }
 114};
 115
 116int fimc_is_register_i2c_driver(void)
 117{
 118        return platform_driver_register(&fimc_is_i2c_driver);
 119}
 120
 121void fimc_is_unregister_i2c_driver(void)
 122{
 123        platform_driver_unregister(&fimc_is_i2c_driver);
 124}
 125