drivers/reset/reset-uniphier-usb3.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // reset-uniphier-usb3.c - USB3 reset driver for UniPhier
   4 // Copyright 2018 Socionext Inc.
   5 // Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
   6
   7 #include <linux/clk.h>
   8 #include <linux/module.h>
   9 #include <linux/of_device.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/reset.h>
  12
  13 #include "reset-simple.h"
  14
  15 #define MAX_CLKS        2
  16 #define MAX_RSTS        2
  17
  18 struct uniphier_usb3_reset_soc_data {
  19         int nclks;
  20         const char * const *clock_names;
  21         int nrsts;
  22         const char * const *reset_names;
  23 };
  24
  25 struct uniphier_usb3_reset_priv {
  26         struct clk_bulk_data clk[MAX_CLKS];
  27         struct reset_control *rst[MAX_RSTS];
  28         struct reset_simple_data rdata;
  29         const struct uniphier_usb3_reset_soc_data *data;
  30 };
  31
  32 static int uniphier_usb3_reset_probe(struct platform_device *pdev)
  33 {
  34         struct device *dev = &pdev->dev;
  35         struct uniphier_usb3_reset_priv *priv;
  36         struct resource *res;
  37         resource_size_t size;
  38         const char *name;
  39         int i, ret, nr;
  40
  41         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  42         if (!priv)
  43                 return -ENOMEM;
  44
  45         priv->data = of_device_get_match_data(dev);
  46         if (WARN_ON(!priv->data || priv->data->nclks > MAX_CLKS ||
  47                     priv->data->nrsts > MAX_RSTS))
  48                 return -EINVAL;
  49
  50         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  51         size = resource_size(res);
  52         priv->rdata.membase = devm_ioremap_resource(dev, res);
  53         if (IS_ERR(priv->rdata.membase))
  54                 return PTR_ERR(priv->rdata.membase);
  55
  56         for (i = 0; i < priv->data->nclks; i++)
  57                 priv->clk[i].id = priv->data->clock_names[i];
  58         ret = devm_clk_bulk_get(dev, priv->data->nclks, priv->clk);
  59         if (ret)
  60                 return ret;
  61
  62         for (i = 0; i < priv->data->nrsts; i++) {
  63                 name = priv->data->reset_names[i];
  64                 priv->rst[i] = devm_reset_control_get_shared(dev, name);
  65                 if (IS_ERR(priv->rst[i]))
  66                         return PTR_ERR(priv->rst[i]);
  67         }
  68
  69         ret = clk_bulk_prepare_enable(priv->data->nclks, priv->clk);
  70         if (ret)
  71                 return ret;
  72
  73         for (nr = 0; nr < priv->data->nrsts; nr++) {
  74                 ret = reset_control_deassert(priv->rst[nr]);
  75                 if (ret)
  76                         goto out_rst_assert;
  77         }
  78
  79         spin_lock_init(&priv->rdata.lock);
  80         priv->rdata.rcdev.owner = THIS_MODULE;
  81         priv->rdata.rcdev.nr_resets = size * BITS_PER_BYTE;
  82         priv->rdata.rcdev.ops = &reset_simple_ops;
  83         priv->rdata.rcdev.of_node = dev->of_node;
  84         priv->rdata.active_low = true;
  85
  86         platform_set_drvdata(pdev, priv);
  87
  88         ret = devm_reset_controller_register(dev, &priv->rdata.rcdev);
  89         if (ret)
  90                 goto out_rst_assert;
  91
  92         return 0;
  93
  94 out_rst_assert:
  95         while (nr--)
  96                 reset_control_assert(priv->rst[nr]);
  97
  98         clk_bulk_disable_unprepare(priv->data->nclks, priv->clk);
  99
 100         return ret;
 101 }
 102
 103 static int uniphier_usb3_reset_remove(struct platform_device *pdev)
 104 {
 105         struct uniphier_usb3_reset_priv *priv = platform_get_drvdata(pdev);
 106         int i;
 107
 108         for (i = 0; i < priv->data->nrsts; i++)
 109                 reset_control_assert(priv->rst[i]);
 110
 111         clk_bulk_disable_unprepare(priv->data->nclks, priv->clk);
 112
 113         return 0;
 114 }
 115
 116 static const char * const uniphier_pro4_clock_reset_names[] = {
 117         "gio", "link",
 118 };
 119
 120 static const struct uniphier_usb3_reset_soc_data uniphier_pro4_data = {
 121         .nclks = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
 122         .clock_names = uniphier_pro4_clock_reset_names,
 123         .nrsts = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
 124         .reset_names = uniphier_pro4_clock_reset_names,
 125 };
 126
 127 static const char * const uniphier_pxs2_clock_reset_names[] = {
 128         "link",
 129 };
 130
 131 static const struct uniphier_usb3_reset_soc_data uniphier_pxs2_data = {
 132         .nclks = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
 133         .clock_names = uniphier_pxs2_clock_reset_names,
 134         .nrsts = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
 135         .reset_names = uniphier_pxs2_clock_reset_names,
 136 };
 137
 138 static const struct of_device_id uniphier_usb3_reset_match[] = {
 139         {
 140                 .compatible = "socionext,uniphier-pro4-usb3-reset",
 141                 .data = &uniphier_pro4_data,
 142         },
 143         {
 144                 .compatible = "socionext,uniphier-pxs2-usb3-reset",
 145                 .data = &uniphier_pxs2_data,
 146         },
 147         {
 148                 .compatible = "socionext,uniphier-ld20-usb3-reset",
 149                 .data = &uniphier_pxs2_data,
 150         },
 151         {
 152                 .compatible = "socionext,uniphier-pxs3-usb3-reset",
 153                 .data = &uniphier_pxs2_data,
 154         },
 155         { /* Sentinel */ }
 156 };
 157 MODULE_DEVICE_TABLE(of, uniphier_usb3_reset_match);
 158
 159 static struct platform_driver uniphier_usb3_reset_driver = {
 160         .probe = uniphier_usb3_reset_probe,
 161         .remove = uniphier_usb3_reset_remove,
 162         .driver = {
 163                 .name = "uniphier-usb3-reset",
 164                 .of_match_table = uniphier_usb3_reset_match,
 165         },
 166 };
 167 module_platform_driver(uniphier_usb3_reset_driver);
 168
 169 MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
 170 MODULE_DESCRIPTION("UniPhier USB3 Reset Driver");
 171 MODULE_LICENSE("GPL");