mmc: pwrseq: add support for Marvell SD8787 chip

Allow power sequencing for the Marvell SD8787 Wifi/BT chip.
This can be abstracted to other chipsets if needed in the future.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/Kconfig

@@ -12,6 +12,16 @@ config PWRSEQ_EMMC
 	  This driver can also be built as a module. If so, the module
 	  will be called pwrseq_emmc.
 
+config PWRSEQ_SD8787
+	tristate "HW reset support for SD8787 BT + Wifi module"
+	depends on OF && (MWIFIEX || BT_MRVL_SDIO)
+	help
+	  This selects hardware reset support for the SD8787 BT + Wifi
+	  module. By default this option is set to n.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called pwrseq_sd8787.
+
 config PWRSEQ_SIMPLE
 	tristate "Simple HW reset support for MMC"
 	default y

drivers/mmc/core/Makefile

@@ -10,6 +10,7 @@ mmc_core-y			:= core.o bus.o host.o \
 				   quirks.o slot-gpio.o
 mmc_core-$(CONFIG_OF)		+= pwrseq.o
 obj-$(CONFIG_PWRSEQ_SIMPLE)	+= pwrseq_simple.o
+obj-$(CONFIG_PWRSEQ_SD8787)	+= pwrseq_sd8787.o
 obj-$(CONFIG_PWRSEQ_EMMC)	+= pwrseq_emmc.o
 mmc_core-$(CONFIG_DEBUG_FS)	+= debugfs.o
 obj-$(CONFIG_MMC_BLOCK)		+= mmc_block.o

drivers/mmc/core/pwrseq_sd8787.c

@@ -0,0 +1,117 @@
+/*
+ * pwrseq_sd8787.c - power sequence support for Marvell SD8787 BT + Wifi chip
+ *
+ * Copyright (C) 2016 Matt Ranostay <matt@ranostay.consulting>
+ *
+ * Based on the original work pwrseq_simple.c
+ *  Copyright (C) 2014 Linaro Ltd
+ *  Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+
+#include <linux/mmc/host.h>
+
+#include "pwrseq.h"
+
+struct mmc_pwrseq_sd8787 {
+	struct mmc_pwrseq pwrseq;
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *pwrdn_gpio;
+};
+
+#define to_pwrseq_sd8787(p) container_of(p, struct mmc_pwrseq_sd8787, pwrseq)
+
+static void mmc_pwrseq_sd8787_pre_power_on(struct mmc_host *host)
+{
+	struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
+
+	gpiod_set_value_cansleep(pwrseq->reset_gpio, 1);
+
+	msleep(300);
+	gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 1);
+}
+
+static void mmc_pwrseq_sd8787_power_off(struct mmc_host *host)
+{
+	struct mmc_pwrseq_sd8787 *pwrseq = to_pwrseq_sd8787(host->pwrseq);
+
+	gpiod_set_value_cansleep(pwrseq->pwrdn_gpio, 0);
+	gpiod_set_value_cansleep(pwrseq->reset_gpio, 0);
+}
+
+static const struct mmc_pwrseq_ops mmc_pwrseq_sd8787_ops = {
+	.pre_power_on = mmc_pwrseq_sd8787_pre_power_on,
+	.power_off = mmc_pwrseq_sd8787_power_off,
+};
+
+static const struct of_device_id mmc_pwrseq_sd8787_of_match[] = {
+	{ .compatible = "mmc-pwrseq-sd8787",},
+	{/* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, mmc_pwrseq_sd8787_of_match);
+
+static int mmc_pwrseq_sd8787_probe(struct platform_device *pdev)
+{
+	struct mmc_pwrseq_sd8787 *pwrseq;
+	struct device *dev = &pdev->dev;
+
+	pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
+	if (!pwrseq)
+		return -ENOMEM;
+
+	pwrseq->pwrdn_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_LOW);
+	if (IS_ERR(pwrseq->pwrdn_gpio))
+		return PTR_ERR(pwrseq->pwrdn_gpio);
+
+	pwrseq->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(pwrseq->reset_gpio))
+		return PTR_ERR(pwrseq->reset_gpio);
+
+	pwrseq->pwrseq.dev = dev;
+	pwrseq->pwrseq.ops = &mmc_pwrseq_sd8787_ops;
+	pwrseq->pwrseq.owner = THIS_MODULE;
+	platform_set_drvdata(pdev, pwrseq);
+
+	return mmc_pwrseq_register(&pwrseq->pwrseq);
+}
+
+static int mmc_pwrseq_sd8787_remove(struct platform_device *pdev)
+{
+	struct mmc_pwrseq_sd8787 *pwrseq = platform_get_drvdata(pdev);
+
+	mmc_pwrseq_unregister(&pwrseq->pwrseq);
+
+	return 0;
+}
+
+static struct platform_driver mmc_pwrseq_sd8787_driver = {
+	.probe = mmc_pwrseq_sd8787_probe,
+	.remove = mmc_pwrseq_sd8787_remove,
+	.driver = {
+		.name = "pwrseq_sd8787",
+		.of_match_table = mmc_pwrseq_sd8787_of_match,
+	},
+};
+
+module_platform_driver(mmc_pwrseq_sd8787_driver);
+MODULE_LICENSE("GPL v2");