drivers/mmc/core/pwrseq_sd8787.c

   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
  26 struct 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
  34 static 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
  44 static 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
  52 static 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
  57 static const struct of_device_id mmc_pwrseq_sd8787_of_match[] = {
  58         { .compatible = "mmc-pwrseq-sd8787",},
  59         {/* sentinel */},
  60 };
  61 MODULE_DEVICE_TABLE(of, mmc_pwrseq_sd8787_of_match);
  62
  63 static 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
  88 static 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
  97 static 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
 106 module_platform_driver(mmc_pwrseq_sd8787_driver);
 107 MODULE_LICENSE("GPL v2");