[PATCH] mmc: pwrseq: add support for Marvell SD8787 chip

[Matt Ranostay]

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@xxxxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Signed-off-by: Matt Ranostay <matt@xxxxxxxxxxxxxxxxxxx>
---
 .../devicetree/bindings/mmc/mmc-pwrseq-sd8787.txt  |  14 +++
 .../bindings/net/wireless/marvell-sd8xxx.txt       |   4 +
 drivers/mmc/core/Kconfig                           |  10 ++
 drivers/mmc/core/Makefile                          |   1 +
 drivers/mmc/core/pwrseq_sd8787.c                   | 117 +++++++++++++++++++++
 5 files changed, 146 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/mmc-pwrseq-sd8787.txt
 create mode 100644 drivers/mmc/core/pwrseq_sd8787.c

diff --git a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-sd8787.txt b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-sd8787.txt
new file mode 100644
index 000000000000..1b658351629b
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-sd8787.txt
@@ -0,0 +1,14 @@
+* Marvell SD8787 power sequence provider
+
+Required properties:
+- compatible: must be "mmc-pwrseq-sd8787".
+- pwndn-gpio: contains a power down GPIO specifier.
+- reset-gpio: contains a reset GPIO specifier.
+
+Example:
+
+	wifi_pwrseq: wifi_pwrseq {
+		compatible = "mmc-pwrseq-sd8787";
+		pwrdn-gpio = <&twl_gpio 0 GPIO_ACTIVE_LOW>;
+		reset-gpio = <&twl_gpio 1 GPIO_ACTIVE_LOW>;
+	}
diff --git a/Documentation/devicetree/bindings/net/wireless/marvell-sd8xxx.txt b/Documentation/devicetree/bindings/net/wireless/marvell-sd8xxx.txt
index c421aba0a5bc..08fd65d35725 100644
--- a/Documentation/devicetree/bindings/net/wireless/marvell-sd8xxx.txt
+++ b/Documentation/devicetree/bindings/net/wireless/marvell-sd8xxx.txt
@@ -32,6 +32,9 @@ Optional properties:
 		 so that the wifi chip can wakeup host platform under certain condition.
 		 during system resume, the irq will be disabled to make sure
 		 unnecessary interrupt is not received.
+  - vmmc-supply: a phandle of a regulator, supplying VCC to the card
+  - mmc-pwrseq:  phandle to the MMC power sequence node. See "mmc-pwrseq-*"
+		 for documentation of MMC power sequence bindings.
 
 Example:
 
@@ -44,6 +47,7 @@ so that firmware can wakeup host using this device side pin.
 &mmc3 {
 	status = "okay";
 	vmmc-supply = <&wlan_en_reg>;
+	mmc-pwrseq = <&wifi_pwrseq>;
 	bus-width = <4>;
 	cap-power-off-card;
 	keep-power-in-suspend;
diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig
index 250f223aaa80..cf61d676ac06 100644
--- a/drivers/mmc/core/Kconfig
+++ b/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
diff --git a/drivers/mmc/core/Makefile b/drivers/mmc/core/Makefile
index f007151dfdc6..f1c060e56d4e 100644
--- a/drivers/mmc/core/Makefile
+++ b/drivers/mmc/core/Makefile
@@ -10,5 +10,6 @@ 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
diff --git a/drivers/mmc/core/pwrseq_sd8787.c b/drivers/mmc/core/pwrseq_sd8787.c
new file mode 100644
index 000000000000..f4080fe6439e
--- /dev/null
+++ b/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@xxxxxxxxxxxxxxxxxxx>
+ *
+ * Based on the original work pwrseq_simple.c
+ *  Copyright (C) 2014 Linaro Ltd
+ *  Author: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
+ *
+ * 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, "pwrdn", 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");
-- 
2.7.4