gpio: add tps65218 gpio

Driver for the GPIO block found in ti's tps65218 pmics.

The device has two GPIOs and one GPO pin which can be configured as follows:
GPIO1:
	-general-purpose, open-drain output controlled by GPO1 user bit and/or
	 sequencer
	-DDR3 reset input signal from SOC. Signal is either latched or
	 passed-trough to GPO2 pin. See below for details.
GPO2:
	-general-purpose output controlled by GPO2 user bit
	-DDR3 reset output signal. Signal is controlled by GPIO1 and PGOOD.
	 See below for details.
	-Output buffer can be configured as open-drain or push-pull.
GPIO3:
	-general-purpose, open-drain output controlled by GPO3 user bit and/or
	 sequencer
	-reset input-signal for DCDC1 and DCDC2.

The input configurations are not meant to be used by the user so the driver
only offers GPOs.

v2: Added request routine that evaluates the fw config flags and removed module
    owner
v3: Added .direction_input() routine, and took care of all Linus Walleij
suggestions (clamp to bool, use proper include)

Signed-off-by: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -889,6 +889,13 @@ config GPIO_TIMBERDALE
 	---help---
 	Add support for the GPIO IP in the timberdale FPGA.
 
+config GPIO_TPS65218
+	tristate "TPS65218 GPIO"
+	depends on MFD_TPS65218
+	help
+	  Select this option to enable GPIO driver for the TPS65218
+	  chip family.
+
 config GPIO_TPS6586X
 	bool "TPS6586X GPIO"
 	depends on MFD_TPS6586X

drivers/gpio/Makefile

@@ -98,6 +98,7 @@ obj-$(CONFIG_ARCH_TEGRA)	+= gpio-tegra.o
 obj-$(CONFIG_GPIO_TIMBERDALE)	+= gpio-timberdale.o
 obj-$(CONFIG_GPIO_PALMAS)	+= gpio-palmas.o
 obj-$(CONFIG_GPIO_TPIC2810)	+= gpio-tpic2810.o
+obj-$(CONFIG_GPIO_TPS65218)	+= gpio-tps65218.o
 obj-$(CONFIG_GPIO_TPS6586X)	+= gpio-tps6586x.o
 obj-$(CONFIG_GPIO_TPS65910)	+= gpio-tps65910.o
 obj-$(CONFIG_GPIO_TPS65912)	+= gpio-tps65912.o

drivers/gpio/gpio-tps65218.c

@@ -0,0 +1,223 @@
+/*
+ * Copyright 2015 Verifone Int.
+ *
+ * Author: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify i t
+ * under  the terms of the GNU General  Public License as published by th e
+ * Free Software Foundation;  either version 2 of the License, or (at you r
+ * option) any later version.
+ *
+ * This driver is based on the gpio-tps65912 implementation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/tps65218.h>
+#include "gpiolib.h"
+
+struct tps65218_gpio {
+	struct tps65218 *tps65218;
+	struct gpio_chip gpio_chip;
+};
+
+static int tps65218_gpio_get(struct gpio_chip *gc, unsigned offset)
+{
+	struct tps65218_gpio *tps65218_gpio = gpiochip_get_data(gc);
+	struct tps65218 *tps65218 = tps65218_gpio->tps65218;
+	unsigned int val;
+	int ret;
+
+	ret = tps65218_reg_read(tps65218, TPS65218_REG_ENABLE2, &val);
+	if (ret)
+		return ret;
+
+	return !!(val & (TPS65218_ENABLE2_GPIO1 << offset));
+}
+
+static void tps65218_gpio_set(struct gpio_chip *gc, unsigned offset,
+			      int value)
+{
+	struct tps65218_gpio *tps65218_gpio = gpiochip_get_data(gc);
+	struct tps65218 *tps65218 = tps65218_gpio->tps65218;
+
+	if (value)
+		tps65218_set_bits(tps65218, TPS65218_REG_ENABLE2,
+				  TPS65218_ENABLE2_GPIO1 << offset,
+				  TPS65218_ENABLE2_GPIO1 << offset,
+				  TPS65218_PROTECT_L1);
+	else
+		tps65218_clear_bits(tps65218, TPS65218_REG_ENABLE2,
+				    TPS65218_ENABLE2_GPIO1 << offset,
+				    TPS65218_PROTECT_L1);
+}
+
+static int tps65218_gpio_output(struct gpio_chip *gc, unsigned offset,
+				int value)
+{
+	/* Only drives GPOs */
+	return 0;
+}
+
+static int tps65218_gpio_input(struct gpio_chip *gc, unsigned offset)
+{
+	return -EPERM;
+}
+
+static int tps65218_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+	struct tps65218_gpio *tps65218_gpio = gpiochip_get_data(gc);
+	struct tps65218 *tps65218 = tps65218_gpio->tps65218;
+	unsigned long flags = gc->desc[offset].flags;
+	int ret;
+
+	if (flags & FLAG_OPEN_SOURCE) {
+		dev_err(gc->parent, "can't work as open source\n");
+		return -EINVAL;
+	}
+
+	switch (offset) {
+	case 0:
+		if (!(flags & FLAG_OPEN_DRAIN)) {
+			dev_err(gc->parent, "GPO1 works only as open drain\n");
+			return -EINVAL;
+		}
+
+		/* Disable sequencer for GPO1 */
+		ret = tps65218_clear_bits(tps65218, TPS65218_REG_SEQ7,
+					  TPS65218_SEQ7_GPO1_SEQ_MASK,
+					  TPS65218_PROTECT_L1);
+		if (ret)
+			return ret;
+
+		/* Setup GPO1 */
+		ret = tps65218_clear_bits(tps65218, TPS65218_REG_CONFIG1,
+					  TPS65218_CONFIG1_IO1_SEL,
+					  TPS65218_PROTECT_L1);
+		if (ret)
+			return ret;
+
+		break;
+	case 1:
+		/* GP02 is push-pull by default, can be set as open drain. */
+		if (flags & FLAG_OPEN_DRAIN) {
+			ret = tps65218_clear_bits(tps65218,
+						  TPS65218_REG_CONFIG1,
+						  TPS65218_CONFIG1_GPO2_BUF,
+						  TPS65218_PROTECT_L1);
+			if (ret)
+				return ret;
+		}
+
+		/* Setup GPO2 */
+		ret = tps65218_clear_bits(tps65218, TPS65218_REG_CONFIG1,
+					  TPS65218_CONFIG1_IO1_SEL,
+					  TPS65218_PROTECT_L1);
+		if (ret)
+			return ret;
+
+		break;
+
+	case 2:
+		if (!(flags & FLAG_OPEN_DRAIN)) {
+			dev_err(gc->parent, "GPO3 works only as open drain\n");
+			return -EINVAL;
+		}
+
+		/* Disable sequencer for GPO3 */
+		ret = tps65218_clear_bits(tps65218, TPS65218_REG_SEQ7,
+					  TPS65218_SEQ7_GPO3_SEQ_MASK,
+					  TPS65218_PROTECT_L1);
+		if (ret)
+			return ret;
+
+		/* Setup GPO3 */
+		ret = tps65218_clear_bits(tps65218, TPS65218_REG_CONFIG2,
+					  TPS65218_CONFIG2_DC12_RST,
+					  TPS65218_PROTECT_L1);
+		if (ret)
+			return ret;
+
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct gpio_chip template_chip = {
+	.label			= "gpio-tps65218",
+	.owner			= THIS_MODULE,
+	.request		= tps65218_gpio_request,
+	.direction_output	= tps65218_gpio_output,
+	.direction_input	= tps65218_gpio_input,
+	.get			= tps65218_gpio_get,
+	.set			= tps65218_gpio_set,
+	.can_sleep		= true,
+	.ngpio			= 3,
+	.base			= -1,
+};
+
+static int tps65218_gpio_probe(struct platform_device *pdev)
+{
+	struct tps65218 *tps65218 = dev_get_drvdata(pdev->dev.parent);
+	struct tps65218_gpio *tps65218_gpio;
+	int ret;
+
+	tps65218_gpio = devm_kzalloc(&pdev->dev, sizeof(*tps65218_gpio),
+				     GFP_KERNEL);
+	if (!tps65218_gpio)
+		return -ENOMEM;
+
+	tps65218_gpio->tps65218 = tps65218;
+	tps65218_gpio->gpio_chip = template_chip;
+	tps65218_gpio->gpio_chip.parent = &pdev->dev;
+#ifdef CONFIG_OF_GPIO
+	tps65218_gpio->gpio_chip.of_node = pdev->dev.of_node;
+#endif
+
+	ret = gpiochip_add_data(&tps65218_gpio->gpio_chip, tps65218_gpio);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to register gpiochip, %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, tps65218_gpio);
+
+	return ret;
+}
+
+static int tps65218_gpio_remove(struct platform_device *pdev)
+{
+	struct tps65218_gpio *tps65218_gpio = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&tps65218_gpio->gpio_chip);
+
+	return 0;
+}
+
+static const struct of_device_id tps65218_dt_match[] = {
+	{ .compatible = "ti,tps65218-gpio" },
+	{  }
+};
+MODULE_DEVICE_TABLE(of, tps65218_dt_match);
+
+static struct platform_driver tps65218_gpio_driver = {
+	.driver = {
+		.name = "tps65218-gpio",
+		.of_match_table = of_match_ptr(tps65218_dt_match)
+	},
+	.probe = tps65218_gpio_probe,
+	.remove = tps65218_gpio_remove,
+};
+
+module_platform_driver(tps65218_gpio_driver);
+
+MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>");
+MODULE_DESCRIPTION("GPO interface for TPS65218 PMICs");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:tps65218-gpio");