LXR linux/drivers/reset/reset-pistachio.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Pistachio SoC Reset Controller driver
   4 *
   5 * Copyright (C) 2015 Imagination Technologies Ltd.
   6 *
   7 * Author: Damien Horsley <Damien.Horsley@imgtec.com>
   8 */
   9
  10#include <linux/init.h>
  11#include <linux/of.h>
  12#include <linux/platform_device.h>
  13#include <linux/regmap.h>
  14#include <linux/reset-controller.h>
  15#include <linux/slab.h>
  16#include <linux/mfd/syscon.h>
  17
  18#include <dt-bindings/reset/pistachio-resets.h>
  19
  20#define PISTACHIO_SOFT_RESET            0
  21
  22struct pistachio_reset_data {
  23        struct reset_controller_dev     rcdev;
  24        struct regmap                   *periph_regs;
  25};
  26
  27static inline int pistachio_reset_shift(unsigned long id)
  28{
  29        switch (id) {
  30        case PISTACHIO_RESET_I2C0:
  31        case PISTACHIO_RESET_I2C1:
  32        case PISTACHIO_RESET_I2C2:
  33        case PISTACHIO_RESET_I2C3:
  34        case PISTACHIO_RESET_I2S_IN:
  35        case PISTACHIO_RESET_PRL_OUT:
  36        case PISTACHIO_RESET_SPDIF_OUT:
  37        case PISTACHIO_RESET_SPI:
  38        case PISTACHIO_RESET_PWM_PDM:
  39        case PISTACHIO_RESET_UART0:
  40        case PISTACHIO_RESET_UART1:
  41        case PISTACHIO_RESET_QSPI:
  42        case PISTACHIO_RESET_MDC:
  43        case PISTACHIO_RESET_SDHOST:
  44        case PISTACHIO_RESET_ETHERNET:
  45        case PISTACHIO_RESET_IR:
  46        case PISTACHIO_RESET_HASH:
  47        case PISTACHIO_RESET_TIMER:
  48                return id;
  49        case PISTACHIO_RESET_I2S_OUT:
  50        case PISTACHIO_RESET_SPDIF_IN:
  51        case PISTACHIO_RESET_EVT:
  52                return id + 6;
  53        case PISTACHIO_RESET_USB_H:
  54        case PISTACHIO_RESET_USB_PR:
  55        case PISTACHIO_RESET_USB_PHY_PR:
  56        case PISTACHIO_RESET_USB_PHY_PON:
  57                return id + 7;
  58        default:
  59                return -EINVAL;
  60        }
  61}
  62
  63static int pistachio_reset_assert(struct reset_controller_dev *rcdev,
  64                                  unsigned long id)
  65{
  66        struct pistachio_reset_data *rd;
  67        u32 mask;
  68        int shift;
  69
  70        rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
  71        shift = pistachio_reset_shift(id);
  72        if (shift < 0)
  73                return shift;
  74        mask = BIT(shift);
  75
  76        return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
  77                                  mask, mask);
  78}
  79
  80static int pistachio_reset_deassert(struct reset_controller_dev *rcdev,
  81                                    unsigned long id)
  82{
  83        struct pistachio_reset_data *rd;
  84        u32 mask;
  85        int shift;
  86
  87        rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
  88        shift = pistachio_reset_shift(id);
  89        if (shift < 0)
  90                return shift;
  91        mask = BIT(shift);
  92
  93        return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
  94                                  mask, 0);
  95}
  96
  97static const struct reset_control_ops pistachio_reset_ops = {
  98        .assert         = pistachio_reset_assert,
  99        .deassert       = pistachio_reset_deassert,
 100};
 101
 102static int pistachio_reset_probe(struct platform_device *pdev)
 103{
 104        struct pistachio_reset_data *rd;
 105        struct device *dev = &pdev->dev;
 106        struct device_node *np = pdev->dev.of_node;
 107
 108        rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL);
 109        if (!rd)
 110                return -ENOMEM;
 111
 112        rd->periph_regs = syscon_node_to_regmap(np->parent);
 113        if (IS_ERR(rd->periph_regs))
 114                return PTR_ERR(rd->periph_regs);
 115
 116        rd->rcdev.owner = THIS_MODULE;
 117        rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1;
 118        rd->rcdev.ops = &pistachio_reset_ops;
 119        rd->rcdev.of_node = np;
 120
 121        return devm_reset_controller_register(dev, &rd->rcdev);
 122}
 123
 124static const struct of_device_id pistachio_reset_dt_ids[] = {
 125         { .compatible = "img,pistachio-reset", },
 126         { /* sentinel */ },
 127};
 128
 129static struct platform_driver pistachio_reset_driver = {
 130        .probe  = pistachio_reset_probe,
 131        .driver = {
 132                .name           = "pistachio-reset",
 133                .of_match_table = pistachio_reset_dt_ids,
 134        },
 135};
 136builtin_platform_driver(pistachio_reset_driver);
 137