GPIO: Add Palmas GPIO support

Palmas has a maximum of 8 GPIO available but depending on the package and
OTP programming of the chip they may not all be exposed to pins on the
chip

Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
(cherry picked from commit 0f9c01bcec3f032de5bf04213ee7055b068e5d06)

Bug 978821

Change-Id: Ic4bb7f6762535fd77e4b0b507dbc6873270ed33b
Reviewed-on: http://git-master/r/119988
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Pradeep Goudagunta <pgoudagunta@nvidia.com>

3 files changed, 236 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 4e1bd9efe7f4..8c2a23aa209f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -523,4 +523,11 @@ config GPIO_TPS65910
 	help
 	  Select this option to enable GPIO driver for the TPS65910
 	  chip family.
+
+config GPIO_PALMAS
+	bool "PALMAS GPIO"
+	depends on MFD_PALMAS
+	help
+	  Select this option to enable GPIO driver for the Palmas
+	  chip familly.
 endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index a27bf53aecea..3b7579647446 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_GPIO_MXC)		+= gpio-mxc.o
 obj-$(CONFIG_GPIO_MXS)		+= gpio-mxs.o
 obj-$(CONFIG_PLAT_NOMADIK)	+= gpio-nomadik.o
 obj-$(CONFIG_ARCH_OMAP)		+= gpio-omap.o
+obj-$(CONFIG_GPIO_PALMAS)	+= gpio-palmas.o
 obj-$(CONFIG_GPIO_PCA953X)	+= gpio-pca953x.o
 obj-$(CONFIG_GPIO_PCF857X)	+= gpio-pcf857x.o
 obj-$(CONFIG_GPIO_PCH)		+= gpio-pch.o
diff --git a/drivers/gpio/gpio-palmas.c b/drivers/gpio/gpio-palmas.c
new file mode 100644
index 000000000000..1956ff183b02
--- /dev/null
+++ b/drivers/gpio/gpio-palmas.c
@@ -0,0 +1,228 @@
+/*
+ * gpiolib support for Palmas Series PMICS
+ *
+ * Copyright 2011 Texas Instruments
+ *
+ * Author: Graeme Gregory <gg@slimlogic.co.uk>
+ *
+ * Based on gpio-wm831x.c
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ *  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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+#include <linux/seq_file.h>
+
+#include <linux/mfd/palmas.h>
+
+struct palmas_gpio {
+	struct palmas *palmas;
+	struct gpio_chip gpio_chip;
+};
+
+static inline struct palmas_gpio *to_palmas_gpio(struct gpio_chip *chip)
+{
+	return container_of(chip, struct palmas_gpio, gpio_chip);
+}
+
+static int palmas_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+	struct palmas_gpio *palmas_gpio = to_palmas_gpio(chip);
+	struct palmas *palmas = palmas_gpio->palmas;
+	int ret;
+	u8 reg = 0;
+
+	if (!((1 << offset) & palmas->gpio_muxed))
+		return -EINVAL;
+
+	ret = palmas_gpio_read(palmas, PALMAS_GPIO_DATA_DIR, &reg);
+	if (ret)
+		return ret;
+
+	reg &= ~(1 << offset);
+
+	return palmas_gpio_write(palmas, PALMAS_GPIO_DATA_DIR, reg);
+}
+
+static int palmas_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct palmas_gpio *palmas_gpio = to_palmas_gpio(chip);
+	struct palmas *palmas = palmas_gpio->palmas;
+	u8 reg = 0;
+
+	if (!((1 << offset) & palmas->gpio_muxed))
+		return 0;
+
+	palmas_gpio_read(palmas, PALMAS_GPIO_DATA_IN, &reg);
+
+	return !!(reg & (1 << offset));
+}
+
+static void palmas_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct palmas_gpio *palmas_gpio = to_palmas_gpio(chip);
+	struct palmas *palmas = palmas_gpio->palmas;
+	u8 reg;
+
+	if (!((1 << offset) & palmas->gpio_muxed))
+		return;
+
+	palmas_gpio_read(palmas, PALMAS_GPIO_DATA_OUT, &reg);
+
+	reg &= ~(1 << offset);
+	reg |= value << offset;
+
+	palmas_gpio_write(palmas, PALMAS_GPIO_DATA_OUT, reg);
+}
+
+static int palmas_gpio_direction_out(struct gpio_chip *chip,
+				     unsigned offset, int value)
+{
+	struct palmas_gpio *palmas_gpio = to_palmas_gpio(chip);
+	struct palmas *palmas = palmas_gpio->palmas;
+	int ret;
+	u8 reg;
+
+	if (!((1 << offset) & palmas->gpio_muxed))
+		return -EINVAL;
+
+	ret = palmas_gpio_read(palmas, PALMAS_GPIO_DATA_DIR, &reg);
+	if (ret)
+		return ret;
+
+	reg |= 1 << offset;
+
+	return palmas_gpio_write(palmas, PALMAS_GPIO_DATA_DIR, reg);
+}
+
+static int palmas_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct palmas_gpio *palmas_gpio = to_palmas_gpio(chip);
+	struct palmas *palmas = palmas_gpio->palmas;
+
+	if (!palmas->irq_base)
+		return -EINVAL;
+
+	return palmas->irq_base + PALMAS_GPIO_0_IRQ + offset;
+}
+
+static int palmas_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
+				    unsigned debounce)
+{
+	struct palmas_gpio *palmas_gpio = to_palmas_gpio(chip);
+	struct palmas *palmas = palmas_gpio->palmas;
+	int ret;
+	u8 reg;
+
+	if (!((1 << offset) & palmas->gpio_muxed))
+		return -EINVAL;
+
+	ret = palmas_gpio_read(palmas, PALMAS_GPIO_DATA_DIR, &reg);
+	if (ret)
+		return ret;
+
+	if (debounce)
+		reg |= 1 << offset;
+	else
+		reg &= ~(1 << offset);
+
+	return palmas_gpio_write(palmas, PALMAS_GPIO_DATA_DIR, reg);
+}
+
+static struct gpio_chip template_chip = {
+	.label			= "palmas",
+	.owner			= THIS_MODULE,
+	.direction_input	= palmas_gpio_direction_in,
+	.get			= palmas_gpio_get,
+	.direction_output	= palmas_gpio_direction_out,
+	.set			= palmas_gpio_set,
+	.to_irq			= palmas_gpio_to_irq,
+	.set_debounce		= palmas_gpio_set_debounce,
+	.can_sleep		= 1,
+	.ngpio			= 8,
+};
+
+static int __devinit palmas_gpio_probe(struct platform_device *pdev)
+{
+	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
+	struct palmas_platform_data *pdata = palmas->dev->platform_data;
+	struct palmas_gpio *gpio;
+	int ret;
+
+	gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
+	if (!gpio)
+		return -ENOMEM;
+
+	gpio->palmas = palmas;
+	gpio->gpio_chip = template_chip;
+	gpio->gpio_chip.dev = &pdev->dev;
+
+	if (pdata && pdata->gpio_base)
+		gpio->gpio_chip.base = pdata->gpio_base;
+	else
+		gpio->gpio_chip.base = -1;
+
+	ret = gpiochip_add(&gpio->gpio_chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
+			ret);
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, gpio);
+
+	return ret;
+
+err:
+	kfree(gpio);
+	return ret;
+}
+
+static int __devexit palmas_gpio_remove(struct platform_device *pdev)
+{
+	struct palmas_gpio *gpio = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = gpiochip_remove(&gpio->gpio_chip);
+	if (ret == 0)
+		kfree(gpio);
+
+	return ret;
+}
+
+static struct platform_driver palmas_gpio_driver = {
+	.driver.name	= "palmas-gpio",
+	.driver.owner	= THIS_MODULE,
+	.probe		= palmas_gpio_probe,
+	.remove		= __devexit_p(palmas_gpio_remove),
+};
+
+static int __init palmas_gpio_init(void)
+{
+	return platform_driver_register(&palmas_gpio_driver);
+}
+subsys_initcall(palmas_gpio_init);
+
+static void __exit palmas_gpio_exit(void)
+{
+	platform_driver_unregister(&palmas_gpio_driver);
+}
+module_exit(palmas_gpio_exit);
+
+MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
+MODULE_DESCRIPTION("GPIO interface for the Palmas series chips");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:palmas-gpio");