LXR linux/drivers/mmc/core/pwrseq

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * pwrseq_sd8787.c - power sequence support for Marvell SD8787 BT + Wifi chip
   4 *
   5 * Copyright (C) 2016 Matt Ranostay <matt@ranostay.consulting>
   6 *
   7 * Based on the original work pwrseq_simple.c
   8 *  Copyright (C) 2014 Linaro Ltd
   9 *  Author: Ulf Hansson <ulf.hansson@linaro.org>
  10 */
  11
  12#include <linux/delay.h>
  13#include <linux/init.h>
  14#include <linux/kernel.h>
  15#include <linux/platform_device.h>
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18#include <linux/device.h>
  19#include <linux/err.h>
  20#include <linux/gpio/consumer.h>
  21
  22#include <linux/mmc/host.h>
  23
  24#include "pwrseq.h"
  25
  26struct mmc_pwrseq_sd8787 {
  27        struct mmc_pwrseq pwrseq;
  28        struct gpio_desc *reset_gpio;
  29        struct gpio_desc *pwrdn_gpio;
  30};
  31
  32#define to_pwrseq_sd8787(p) container_of(p, struct mmc_pwrseq_sd8787, pwrseq)
  33
  34static void mmc_pwrseq_sd8787_pre_power_on(struct mmc_host *host)
  35{
  36        struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
  37
  38        gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
  39
  40        msleep(300);
  41        gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 1);
  42}
  43
  44static void mmc_pwrseq_sd8787_power_off(struct mmc_host *host)
  45{
  46        struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
  47
  48        gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 0);
  49        gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
  50}
  51
  52static const struct mmc_pwrseq_ops mmc_pwrseq_sd8787_ops = {
  53        .pre_power_on = mmc_pwrseq_sd8787_pre_power_on,
  54        .power_off = mmc_pwrseq_sd8787_power_off,
  55};
  56
  57static const struct of_device_id mmc_pwrseq_sd8787_of_match[] = {
  58        { .compatible = "mmc-pwrseq-sd8787",},
  59        {/* sentinel */},
  60};
  61MODULE_DEVICE_TABLE(of, mmc_pwrseq_sd8787_of_match);
  62
  63static int mmc_pwrseq_sd8787_probe(struct platform_device *pdev)
  64{
  65        struct mmc_pwrseq_sd8787 *pwrseq;
  66        struct device *dev = &pdev->dev;
  67
  68        pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
  69        if (!pwrseq)
  70                return -ENOMEM;
  71
  72        pwrseq->pwrdn_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_LOW);
  73        if (IS_ERR(pwrseq->pwrdn_gpio))
  74                return PTR_ERR(pwrseq->pwrdn_gpio);
  75
  76        pwrseq->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
  77        if (IS_ERR(pwrseq->reset_gpio))
  78                return PTR_ERR(pwrseq->reset_gpio);
  79
  80        pwrseq->pwrseq.dev = dev;
  81        pwrseq->pwrseq.ops = &mmc_pwrseq_sd8787_ops;
  82        pwrseq->pwrseq.owner = THIS_MODULE;
  83        platform_set_drvdata(pdev, pwrseq);
  84
  85        return mmc_pwrseq_register(&pwrseq->pwrseq);
  86}
  87
  88static int mmc_pwrseq_sd8787_remove(struct platform_device *pdev)
  89{
  90        struct mmc_pwrseq_sd8787 *pwrseq = platform_get_drvdata(pdev);
  91
  92        mmc_pwrseq_unregister(&pwrseq->pwrseq);
  93
  94        return 0;
  95}
  96
  97static struct platform_driver mmc_pwrseq_sd8787_driver = {
  98        .probe = mmc_pwrseq_sd8787_probe,
  99        .remove = mmc_pwrseq_sd8787_remove,
 100        .driver = {
 101                .name = "pwrseq_sd8787",
 102                .of_match_table = mmc_pwrseq_sd8787_of_match,
 103        },
 104};
 105
 106module_platform_driver(mmc_pwrseq_sd8787_driver);
 107MODULE_LICENSE("GPL v2");
 108