drivers/reset/reset-imx8mp-audiomix.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2024 NXP
   4  */
   5
   6 #include <linux/auxiliary_bus.h>
   7 #include <linux/device.h>
   8 #include <linux/io.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/of_address.h>
  12 #include <linux/reset-controller.h>
  13
  14 #define EARC                    0x200
  15 #define EARC_RESET_MASK         0x3
  16
  17 struct imx8mp_audiomix_reset {
  18         struct reset_controller_dev rcdev;
  19         spinlock_t lock; /* protect register read-modify-write cycle */
  20         void __iomem *base;
  21 };
  22
  23 static struct imx8mp_audiomix_reset *to_imx8mp_audiomix_reset(struct reset_controller_dev *rcdev)
  24 {
  25         return container_of(rcdev, struct imx8mp_audiomix_reset, rcdev);
  26 }
  27
  28 static int imx8mp_audiomix_reset_assert(struct reset_controller_dev *rcdev,
  29                                         unsigned long id)
  30 {
  31         struct imx8mp_audiomix_reset *priv = to_imx8mp_audiomix_reset(rcdev);
  32         void __iomem *reg_addr = priv->base;
  33         unsigned int mask, reg;
  34         unsigned long flags;
  35
  36         mask = BIT(id);
  37         spin_lock_irqsave(&priv->lock, flags);
  38         reg = readl(reg_addr + EARC);
  39         writel(reg & ~mask, reg_addr + EARC);
  40         spin_unlock_irqrestore(&priv->lock, flags);
  41
  42         return 0;
  43 }
  44
  45 static int imx8mp_audiomix_reset_deassert(struct reset_controller_dev *rcdev,
  46                                           unsigned long id)
  47 {
  48         struct imx8mp_audiomix_reset *priv = to_imx8mp_audiomix_reset(rcdev);
  49         void __iomem *reg_addr = priv->base;
  50         unsigned int mask, reg;
  51         unsigned long flags;
  52
  53         mask = BIT(id);
  54         spin_lock_irqsave(&priv->lock, flags);
  55         reg = readl(reg_addr + EARC);
  56         writel(reg | mask, reg_addr + EARC);
  57         spin_unlock_irqrestore(&priv->lock, flags);
  58
  59         return 0;
  60 }
  61
  62 static const struct reset_control_ops imx8mp_audiomix_reset_ops = {
  63         .assert   = imx8mp_audiomix_reset_assert,
  64         .deassert = imx8mp_audiomix_reset_deassert,
  65 };
  66
  67 static int imx8mp_audiomix_reset_probe(struct auxiliary_device *adev,
  68                                        const struct auxiliary_device_id *id)
  69 {
  70         struct imx8mp_audiomix_reset *priv;
  71         struct device *dev = &adev->dev;
  72         int ret;
  73
  74         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  75         if (!priv)
  76                 return -ENOMEM;
  77
  78         spin_lock_init(&priv->lock);
  79
  80         priv->rcdev.owner     = THIS_MODULE;
  81         priv->rcdev.nr_resets = fls(EARC_RESET_MASK);
  82         priv->rcdev.ops       = &imx8mp_audiomix_reset_ops;
  83         priv->rcdev.of_node   = dev->parent->of_node;
  84         priv->rcdev.dev       = dev;
  85         priv->rcdev.of_reset_n_cells = 1;
  86         priv->base            = of_iomap(dev->parent->of_node, 0);
  87         if (!priv->base)
  88                 return -ENOMEM;
  89
  90         dev_set_drvdata(dev, priv);
  91
  92         ret = devm_reset_controller_register(dev, &priv->rcdev);
  93         if (ret)
  94                 goto out_unmap;
  95
  96         return 0;
  97
  98 out_unmap:
  99         iounmap(priv->base);
 100         return ret;
 101 }
 102
 103 static void imx8mp_audiomix_reset_remove(struct auxiliary_device *adev)
 104 {
 105         struct imx8mp_audiomix_reset *priv = dev_get_drvdata(&adev->dev);
 106
 107         iounmap(priv->base);
 108 }
 109
 110 static const struct auxiliary_device_id imx8mp_audiomix_reset_ids[] = {
 111         {
 112                 .name = "clk_imx8mp_audiomix.reset",
 113         },
 114         { }
 115 };
 116 MODULE_DEVICE_TABLE(auxiliary, imx8mp_audiomix_reset_ids);
 117
 118 static struct auxiliary_driver imx8mp_audiomix_reset_driver = {
 119         .probe          = imx8mp_audiomix_reset_probe,
 120         .remove         = imx8mp_audiomix_reset_remove,
 121         .id_table       = imx8mp_audiomix_reset_ids,
 122 };
 123
 124 module_auxiliary_driver(imx8mp_audiomix_reset_driver);
 125
 126 MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
 127 MODULE_DESCRIPTION("Freescale i.MX8MP Audio Block Controller reset driver");
 128 MODULE_LICENSE("GPL");