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"); 118