arch/arm/mach-exynos/setup-usb-phy.c

   1 /*
   2  * Copyright (C) 2011 Samsung Electronics Co.Ltd
   3  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
   4  *
   5  *  This program is free software; you can redistribute  it and/or modify it
   6  *  under  the terms of  the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the  License, or (at your
   8  *  option) any later version.
   9  *
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/delay.h>
  14 #include <linux/err.h>
  15 #include <linux/io.h>
  16 #include <linux/platform_device.h>
  17 #include <mach/regs-pmu.h>
  18 #include <mach/regs-usb-phy.h>
  19 #include <plat/cpu.h>
  20 #include <plat/usb-phy.h>
  21
  22 static atomic_t host_usage;
  23
  24 static int exynos4_usb_host_phy_is_on(void)
  25 {
  26         return (readl(EXYNOS4_PHYPWR) & PHY1_STD_ANALOG_POWERDOWN) ? 0 : 1;
  27 }
  28
  29 static int exynos4_usb_phy1_init(struct platform_device *pdev)
  30 {
  31         struct clk *otg_clk;
  32         struct clk *xusbxti_clk;
  33         u32 phyclk;
  34         u32 rstcon;
  35         int err;
  36
  37         atomic_inc(&host_usage);
  38
  39         otg_clk = clk_get(&pdev->dev, "otg");
  40         if (IS_ERR(otg_clk)) {
  41                 dev_err(&pdev->dev, "Failed to get otg clock\n");
  42                 return PTR_ERR(otg_clk);
  43         }
  44
  45         err = clk_enable(otg_clk);
  46         if (err) {
  47                 clk_put(otg_clk);
  48                 return err;
  49         }
  50
  51         if (exynos4_usb_host_phy_is_on())
  52                 return 0;
  53
  54         writel(readl(S5P_USBHOST_PHY_CONTROL) | S5P_USBHOST_PHY_ENABLE,
  55                         S5P_USBHOST_PHY_CONTROL);
  56
  57         /* set clock frequency for PLL */
  58         phyclk = readl(EXYNOS4_PHYCLK) & ~CLKSEL_MASK;
  59
  60         xusbxti_clk = clk_get(&pdev->dev, "xusbxti");
  61         if (xusbxti_clk && !IS_ERR(xusbxti_clk)) {
  62                 switch (clk_get_rate(xusbxti_clk)) {
  63                 case 12 * MHZ:
  64                         phyclk |= CLKSEL_12M;
  65                         break;
  66                 case 24 * MHZ:
  67                         phyclk |= CLKSEL_24M;
  68                         break;
  69                 default:
  70                 case 48 * MHZ:
  71                         /* default reference clock */
  72                         break;
  73                 }
  74                 clk_put(xusbxti_clk);
  75         }
  76
  77         writel(phyclk, EXYNOS4_PHYCLK);
  78
  79         /* floating prevention logic: disable */
  80         writel((readl(EXYNOS4_PHY1CON) | FPENABLEN), EXYNOS4_PHY1CON);
  81
  82         /* set to normal HSIC 0 and 1 of PHY1 */
  83         writel((readl(EXYNOS4_PHYPWR) & ~PHY1_HSIC_NORMAL_MASK),
  84                         EXYNOS4_PHYPWR);
  85
  86         /* set to normal standard USB of PHY1 */
  87         writel((readl(EXYNOS4_PHYPWR) & ~PHY1_STD_NORMAL_MASK), EXYNOS4_PHYPWR);
  88
  89         /* reset all ports of both PHY and Link */
  90         rstcon = readl(EXYNOS4_RSTCON) | HOST_LINK_PORT_SWRST_MASK |
  91                 PHY1_SWRST_MASK;
  92         writel(rstcon, EXYNOS4_RSTCON);
  93         udelay(10);
  94
  95         rstcon &= ~(HOST_LINK_PORT_SWRST_MASK | PHY1_SWRST_MASK);
  96         writel(rstcon, EXYNOS4_RSTCON);
  97         udelay(80);
  98
  99         clk_disable(otg_clk);
 100         clk_put(otg_clk);
 101
 102         return 0;
 103 }
 104
 105 static int exynos4_usb_phy1_exit(struct platform_device *pdev)
 106 {
 107         struct clk *otg_clk;
 108         int err;
 109
 110         if (atomic_dec_return(&host_usage) > 0)
 111                 return 0;
 112
 113         otg_clk = clk_get(&pdev->dev, "otg");
 114         if (IS_ERR(otg_clk)) {
 115                 dev_err(&pdev->dev, "Failed to get otg clock\n");
 116                 return PTR_ERR(otg_clk);
 117         }
 118
 119         err = clk_enable(otg_clk);
 120         if (err) {
 121                 clk_put(otg_clk);
 122                 return err;
 123         }
 124
 125         writel((readl(EXYNOS4_PHYPWR) | PHY1_STD_ANALOG_POWERDOWN),
 126                         EXYNOS4_PHYPWR);
 127
 128         writel(readl(S5P_USBHOST_PHY_CONTROL) & ~S5P_USBHOST_PHY_ENABLE,
 129                         S5P_USBHOST_PHY_CONTROL);
 130
 131         clk_disable(otg_clk);
 132         clk_put(otg_clk);
 133
 134         return 0;
 135 }
 136
 137 int s5p_usb_phy_init(struct platform_device *pdev, int type)
 138 {
 139         if (type == S5P_USB_PHY_HOST)
 140                 return exynos4_usb_phy1_init(pdev);
 141
 142         return -EINVAL;
 143 }
 144
 145 int s5p_usb_phy_exit(struct platform_device *pdev, int type)
 146 {
 147         if (type == S5P_USB_PHY_HOST)
 148                 return exynos4_usb_phy1_exit(pdev);
 149
 150         return -EINVAL;
 151 }