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