drivers/reset/reset-rzg2l-usbphy-ctrl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Renesas RZ/G2L USBPHY control driver
   4  *
   5  * Copyright (C) 2021 Renesas Electronics Corporation
   6  */
   7
   8 #include <linux/io.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/pm_runtime.h>
  13 #include <linux/reset.h>
  14 #include <linux/reset-controller.h>
  15
  16 #define RESET                   0x000
  17
  18 #define RESET_SEL_PLLRESET      BIT(12)
  19 #define RESET_PLLRESET          BIT(8)
  20
  21 #define RESET_SEL_P2RESET       BIT(5)
  22 #define RESET_SEL_P1RESET       BIT(4)
  23 #define RESET_PHYRST_2          BIT(1)
  24 #define RESET_PHYRST_1          BIT(0)
  25
  26 #define PHY_RESET_PORT2         (RESET_SEL_P2RESET | RESET_PHYRST_2)
  27 #define PHY_RESET_PORT1         (RESET_SEL_P1RESET | RESET_PHYRST_1)
  28
  29 #define NUM_PORTS               2
  30
  31 struct rzg2l_usbphy_ctrl_priv {
  32         struct reset_controller_dev rcdev;
  33         struct reset_control *rstc;
  34         void __iomem *base;
  35
  36         spinlock_t lock;
  37 };
  38
  39 #define rcdev_to_priv(x)        container_of(x, struct rzg2l_usbphy_ctrl_priv, rcdev)
  40
  41 static int rzg2l_usbphy_ctrl_assert(struct reset_controller_dev *rcdev,
  42                                     unsigned long id)
  43 {
  44         struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
  45         u32 port_mask = PHY_RESET_PORT1 | PHY_RESET_PORT2;
  46         void __iomem *base = priv->base;
  47         unsigned long flags;
  48         u32 val;
  49
  50         spin_lock_irqsave(&priv->lock, flags);
  51         val = readl(base + RESET);
  52         val |= id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
  53         if (port_mask == (val & port_mask))
  54                 val |= RESET_PLLRESET;
  55         writel(val, base + RESET);
  56         spin_unlock_irqrestore(&priv->lock, flags);
  57
  58         return 0;
  59 }
  60
  61 static int rzg2l_usbphy_ctrl_deassert(struct reset_controller_dev *rcdev,
  62                                       unsigned long id)
  63 {
  64         struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
  65         void __iomem *base = priv->base;
  66         unsigned long flags;
  67         u32 val;
  68
  69         spin_lock_irqsave(&priv->lock, flags);
  70         val = readl(base + RESET);
  71
  72         val |= RESET_SEL_PLLRESET;
  73         val &= ~(RESET_PLLRESET | (id ? PHY_RESET_PORT2 : PHY_RESET_PORT1));
  74         writel(val, base + RESET);
  75         spin_unlock_irqrestore(&priv->lock, flags);
  76
  77         return 0;
  78 }
  79
  80 static int rzg2l_usbphy_ctrl_status(struct reset_controller_dev *rcdev,
  81                                     unsigned long id)
  82 {
  83         struct rzg2l_usbphy_ctrl_priv *priv = rcdev_to_priv(rcdev);
  84         u32 port_mask;
  85
  86         port_mask = id ? PHY_RESET_PORT2 : PHY_RESET_PORT1;
  87
  88         return !!(readl(priv->base + RESET) & port_mask);
  89 }
  90
  91 static const struct of_device_id rzg2l_usbphy_ctrl_match_table[] = {
  92         { .compatible = "renesas,rzg2l-usbphy-ctrl" },
  93         { /* Sentinel */ }
  94 };
  95 MODULE_DEVICE_TABLE(of, rzg2l_usbphy_ctrl_match_table);
  96
  97 static const struct reset_control_ops rzg2l_usbphy_ctrl_reset_ops = {
  98         .assert = rzg2l_usbphy_ctrl_assert,
  99         .deassert = rzg2l_usbphy_ctrl_deassert,
 100         .status = rzg2l_usbphy_ctrl_status,
 101 };
 102
 103 static int rzg2l_usbphy_ctrl_probe(struct platform_device *pdev)
 104 {
 105         struct device *dev = &pdev->dev;
 106         struct rzg2l_usbphy_ctrl_priv *priv;
 107         unsigned long flags;
 108         int error;
 109         u32 val;
 110
 111         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 112         if (!priv)
 113                 return -ENOMEM;
 114
 115         priv->base = devm_platform_ioremap_resource(pdev, 0);
 116         if (IS_ERR(priv->base))
 117                 return PTR_ERR(priv->base);
 118
 119         priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 120         if (IS_ERR(priv->rstc))
 121                 return dev_err_probe(dev, PTR_ERR(priv->rstc),
 122                                      "failed to get reset\n");
 123
 124         error = reset_control_deassert(priv->rstc);
 125         if (error)
 126                 return error;
 127
 128         priv->rcdev.ops = &rzg2l_usbphy_ctrl_reset_ops;
 129         priv->rcdev.of_reset_n_cells = 1;
 130         priv->rcdev.nr_resets = NUM_PORTS;
 131         priv->rcdev.of_node = dev->of_node;
 132         priv->rcdev.dev = dev;
 133
 134         error = devm_reset_controller_register(dev, &priv->rcdev);
 135         if (error)
 136                 return error;
 137
 138         spin_lock_init(&priv->lock);
 139         dev_set_drvdata(dev, priv);
 140
 141         pm_runtime_enable(&pdev->dev);
 142         error = pm_runtime_resume_and_get(&pdev->dev);
 143         if (error < 0) {
 144                 pm_runtime_disable(&pdev->dev);
 145                 reset_control_assert(priv->rstc);
 146                 return dev_err_probe(&pdev->dev, error, "pm_runtime_resume_and_get failed");
 147         }
 148
 149         /* put pll and phy into reset state */
 150         spin_lock_irqsave(&priv->lock, flags);
 151         val = readl(priv->base + RESET);
 152         val |= RESET_SEL_PLLRESET | RESET_PLLRESET | PHY_RESET_PORT2 | PHY_RESET_PORT1;
 153         writel(val, priv->base + RESET);
 154         spin_unlock_irqrestore(&priv->lock, flags);
 155
 156         return 0;
 157 }
 158
 159 static int rzg2l_usbphy_ctrl_remove(struct platform_device *pdev)
 160 {
 161         struct rzg2l_usbphy_ctrl_priv *priv = dev_get_drvdata(&pdev->dev);
 162
 163         pm_runtime_put(&pdev->dev);
 164         pm_runtime_disable(&pdev->dev);
 165         reset_control_assert(priv->rstc);
 166
 167         return 0;
 168 }
 169
 170 static struct platform_driver rzg2l_usbphy_ctrl_driver = {
 171         .driver = {
 172                 .name           = "rzg2l_usbphy_ctrl",
 173                 .of_match_table = rzg2l_usbphy_ctrl_match_table,
 174         },
 175         .probe  = rzg2l_usbphy_ctrl_probe,
 176         .remove = rzg2l_usbphy_ctrl_remove,
 177 };
 178 module_platform_driver(rzg2l_usbphy_ctrl_driver);
 179
 180 MODULE_LICENSE("GPL v2");
 181 MODULE_DESCRIPTION("Renesas RZ/G2L USBPHY Control");
 182 MODULE_AUTHOR("biju.das.jz@bp.renesas.com>");