drivers/phy/phy-exynos-dp-video.c

   1 /*
   2  * Samsung EXYNOS SoC series Display Port PHY driver
   3  *
   4  * Copyright (C) 2013 Samsung Electronics Co., Ltd.
   5  * Author: Jingoo Han <jg1.han@samsung.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/phy/phy.h>
  18 #include <linux/platform_device.h>
  19
  20 /* DPTX_PHY_CONTROL register */
  21 #define EXYNOS_DPTX_PHY_ENABLE          (1 << 0)
  22
  23 struct exynos_dp_video_phy {
  24         void __iomem *regs;
  25 };
  26
  27 static int __set_phy_state(struct exynos_dp_video_phy *state, unsigned int on)
  28 {
  29         u32 reg;
  30
  31         reg = readl(state->regs);
  32         if (on)
  33                 reg |= EXYNOS_DPTX_PHY_ENABLE;
  34         else
  35                 reg &= ~EXYNOS_DPTX_PHY_ENABLE;
  36         writel(reg, state->regs);
  37
  38         return 0;
  39 }
  40
  41 static int exynos_dp_video_phy_power_on(struct phy *phy)
  42 {
  43         struct exynos_dp_video_phy *state = phy_get_drvdata(phy);
  44
  45         return __set_phy_state(state, 1);
  46 }
  47
  48 static int exynos_dp_video_phy_power_off(struct phy *phy)
  49 {
  50         struct exynos_dp_video_phy *state = phy_get_drvdata(phy);
  51
  52         return __set_phy_state(state, 0);
  53 }
  54
  55 static struct phy_ops exynos_dp_video_phy_ops = {
  56         .power_on       = exynos_dp_video_phy_power_on,
  57         .power_off      = exynos_dp_video_phy_power_off,
  58         .owner          = THIS_MODULE,
  59 };
  60
  61 static int exynos_dp_video_phy_probe(struct platform_device *pdev)
  62 {
  63         struct exynos_dp_video_phy *state;
  64         struct device *dev = &pdev->dev;
  65         struct resource *res;
  66         struct phy_provider *phy_provider;
  67         struct phy *phy;
  68
  69         state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
  70         if (!state)
  71                 return -ENOMEM;
  72
  73         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  74
  75         state->regs = devm_ioremap_resource(dev, res);
  76         if (IS_ERR(state->regs))
  77                 return PTR_ERR(state->regs);
  78
  79         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
  80         if (IS_ERR(phy_provider))
  81                 return PTR_ERR(phy_provider);
  82
  83         phy = devm_phy_create(dev, &exynos_dp_video_phy_ops, NULL);
  84         if (IS_ERR(phy)) {
  85                 dev_err(dev, "failed to create Display Port PHY\n");
  86                 return PTR_ERR(phy);
  87         }
  88         phy_set_drvdata(phy, state);
  89
  90         return 0;
  91 }
  92
  93 static const struct of_device_id exynos_dp_video_phy_of_match[] = {
  94         { .compatible = "samsung,exynos5250-dp-video-phy" },
  95         { },
  96 };
  97 MODULE_DEVICE_TABLE(of, exynos_dp_video_phy_of_match);
  98
  99 static struct platform_driver exynos_dp_video_phy_driver = {
 100         .probe  = exynos_dp_video_phy_probe,
 101         .driver = {
 102                 .name   = "exynos-dp-video-phy",
 103                 .owner  = THIS_MODULE,
 104                 .of_match_table = exynos_dp_video_phy_of_match,
 105         }
 106 };
 107 module_platform_driver(exynos_dp_video_phy_driver);
 108
 109 MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
 110 MODULE_DESCRIPTION("Samsung EXYNOS SoC DP PHY driver");
 111 MODULE_LICENSE("GPL v2");