drivers/mmc/core/pwrseq_sd8787.c

   1 /*
   2  * pwrseq_sd8787.c - power sequence support for Marvell SD8787 BT + Wifi chip
   3  *
   4  * Copyright (C) 2016 Matt Ranostay <matt@ranostay.consulting>
   5  *
   6  * Based on the original work pwrseq_simple.c
   7  *  Copyright (C) 2014 Linaro Ltd
   8  *  Author: Ulf Hansson <ulf.hansson@linaro.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/device.h>
  29 #include <linux/err.h>
  30 #include <linux/gpio/consumer.h>
  31
  32 #include <linux/mmc/host.h>
  33
  34 #include "pwrseq.h"
  35
  36 struct mmc_pwrseq_sd8787 {
  37         struct mmc_pwrseq pwrseq;
  38         struct gpio_desc *reset_gpio;
  39         struct gpio_desc *pwrdn_gpio;
  40 };
  41
  42 #define to_pwrseq_sd8787(p) container_of(p, struct mmc_pwrseq_sd8787, pwrseq)
  43
  44 static void mmc_pwrseq_sd8787_pre_power_on(struct mmc_host *host)
  45 {
  46         struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
  47
  48         gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
  49
  50         msleep(300);
  51         gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 1);
  52 }
  53
  54 static void mmc_pwrseq_sd8787_power_off(struct mmc_host *host)
  55 {
  56         struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
  57
  58         gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 0);
  59         gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
  60 }
  61
  62 static const struct mmc_pwrseq_ops mmc_pwrseq_sd8787_ops = {
  63         .pre_power_on = mmc_pwrseq_sd8787_pre_power_on,
  64         .power_off = mmc_pwrseq_sd8787_power_off,
  65 };
  66
  67 static const struct of_device_id mmc_pwrseq_sd8787_of_match[] = {
  68         { .compatible = "mmc-pwrseq-sd8787",},
  69         {/* sentinel */},
  70 };
  71 MODULE_DEVICE_TABLE(of, mmc_pwrseq_sd8787_of_match);
  72
  73 static int mmc_pwrseq_sd8787_probe(struct platform_device *pdev)
  74 {
  75         struct mmc_pwrseq_sd8787 *pwrseq;
  76         struct device *dev = &pdev->dev;
  77
  78         pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
  79         if (!pwrseq)
  80                 return -ENOMEM;
  81
  82         pwrseq->pwrdn_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_LOW);
  83         if (IS_ERR(pwrseq->pwrdn_gpio))
  84                 return PTR_ERR(pwrseq->pwrdn_gpio);
  85
  86         pwrseq->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
  87         if (IS_ERR(pwrseq->reset_gpio))
  88                 return PTR_ERR(pwrseq->reset_gpio);
  89
  90         pwrseq->pwrseq.dev = dev;
  91         pwrseq->pwrseq.ops = &mmc_pwrseq_sd8787_ops;
  92         pwrseq->pwrseq.owner = THIS_MODULE;
  93         platform_set_drvdata(pdev, pwrseq);
  94
  95         return mmc_pwrseq_register(&pwrseq->pwrseq);
  96 }
  97
  98 static int mmc_pwrseq_sd8787_remove(struct platform_device *pdev)
  99 {
 100         struct mmc_pwrseq_sd8787 *pwrseq = platform_get_drvdata(pdev);
 101
 102         mmc_pwrseq_unregister(&pwrseq->pwrseq);
 103
 104         return 0;
 105 }
 106
 107 static struct platform_driver mmc_pwrseq_sd8787_driver = {
 108         .probe = mmc_pwrseq_sd8787_probe,
 109         .remove = mmc_pwrseq_sd8787_remove,
 110         .driver = {
 111                 .name = "pwrseq_sd8787",
 112                 .of_match_table = mmc_pwrseq_sd8787_of_match,
 113         },
 114 };
 115
 116 module_platform_driver(mmc_pwrseq_sd8787_driver);
 117 MODULE_LICENSE("GPL v2");