[PATCH] gpio: add Intel WhiskeyCove GPIO driver

[Bin Gao <bin.gao@xxxxxxxxxxxxxxx>]

This patch introduces a separate GPIO driver for Intel WhiskeyCove PMIC.
This driver is based on gpio-crystalcove.c.

Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@xxxxxxxxx>
Signed-off-by: Bin Gao <bin.gao@xxxxxxxxx>
---
 drivers/gpio/Kconfig      |  13 ++
 drivers/gpio/Makefile     |   1 +
 drivers/gpio/gpio-wcove.c | 402 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 416 insertions(+)
 create mode 100644 drivers/gpio/gpio-wcove.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 48da857..0bb6893 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -805,6 +805,19 @@ config GPIO_CRYSTAL_COVE
 	  This driver can also be built as a module. If so, the module will be
 	  called gpio-crystalcove.
 
+config GPIO_WHISKEY_COVE
+	tristate "GPIO support for Whiskey Cove PMIC"
+	depends on INTEL_SOC_PMIC
+	select GPIOLIB_IRQCHIP
+	help
+	  Support for GPIO pins on Whiskey Cove PMIC.
+
+	  Say Yes if you have a Intel SoC based tablet with Whsikey Cove PMIC
+	  inside.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called gpio-wcove.
+
 config GPIO_CS5535
 	tristate "AMD CS5535/CS5536 GPIO support"
 	depends on MFD_CS5535
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 991598e..fff6914 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
 obj-$(CONFIG_GPIO_CLPS711X)	+= gpio-clps711x.o
 obj-$(CONFIG_GPIO_CS5535)	+= gpio-cs5535.o
 obj-$(CONFIG_GPIO_CRYSTAL_COVE)	+= gpio-crystalcove.o
+obj-$(CONFIG_GPIO_WHISKEY_COVE)	+= gpio-wcove.o
 obj-$(CONFIG_GPIO_DA9052)	+= gpio-da9052.o
 obj-$(CONFIG_GPIO_DA9055)	+= gpio-da9055.o
 obj-$(CONFIG_GPIO_DAVINCI)	+= gpio-davinci.o
diff --git a/drivers/gpio/gpio-wcove.c b/drivers/gpio/gpio-wcove.c
new file mode 100644
index 0000000..20d83e3
--- /dev/null
+++ b/drivers/gpio/gpio-wcove.c
@@ -0,0 +1,402 @@
+/*
+ * gpio-wcove.c - Intel Whiskey Cove GPIO Driver
+ *
+ * This driver is written based on gpio-crystalcove.c
+ *
+ * Copyright (C) 2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * 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/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/seq_file.h>
+#include <linux/bitops.h>
+#include <linux/regmap.h>
+#include <linux/mfd/intel_soc_pmic.h>
+
+#define WCOVE_GPIO_NUM	13
+#define WCOVE_VGPIO_NUM	94
+
+#define UPDATE_IRQ_TYPE		BIT(0)
+#define UPDATE_IRQ_MASK		BIT(1)
+
+#define GPIOIRQ0		0x4e0b
+#define GPIOIRQ1		0x4e0c
+#define MGPIOIRQ0		0x4e19
+#define MGPIOIRQ1		0x4e1a
+#define GPIO0P0CTLO		0x4e44
+#define GPIO0P0CTLI		0x4e51
+#define GPIO1P0CTLO		0x4e4b
+#define GPIO1P0CTLI		0x4e58
+#define GPIO2P0CTLO		0x4e4f
+#define GPIO2P0CTLI		0x4e5c
+
+#define CTLI_INTCNT_DIS		(0)
+#define CTLI_INTCNT_NE		(1 << 1)
+#define CTLI_INTCNT_PE		(2 << 1)
+#define CTLI_INTCNT_BE		(3 << 1)
+
+#define CTLO_DIR_IN		(0)
+#define CTLO_DIR_OUT		(1 << 5)
+
+#define CTLO_DRV_CMOS		(0)
+#define CTLO_DRV_OD		(1 << 4)
+
+#define CTLO_DRV_REN		(1 << 3)
+
+#define CTLO_RVAL_2KDW		(0)
+#define CTLO_RVAL_2KUP		(1 << 1)
+#define CTLO_RVAL_50KDW		(2 << 1)
+#define CTLO_RVAL_50KUP		(3 << 1)
+
+#define CTLO_INPUT_SET	(CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
+#define CTLO_OUTPUT_SET	(CTLO_DIR_OUT | CTLO_INPUT_SET)
+
+enum ctrl_register {
+	CTRL_IN,
+	CTRL_OUT,
+};
+
+/*
+ * struct wcove_gpio - Whiskey Cove GPIO controller
+ * @buslock: for bus lock/sync and unlock.
+ * @chip: the abstract gpio_chip structure.
+ * @regmap: the regmap from the parent device.
+ * @update: pending IRQ setting update, to be written to the chip upon unlock.
+ * @intcnt_value: the Interrupt Detect value to be written.
+ * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
+ */
+struct wcove_gpio {
+	struct mutex buslock; /* irq_bus_lock */
+	struct gpio_chip chip;
+	struct regmap *regmap;
+	struct regmap_irq_chip_data *regmap_irq_chip;
+	int update;
+	int intcnt_value;
+	bool set_irq_mask;
+};
+
+static inline struct wcove_gpio *to_wg(struct gpio_chip *gc)
+{
+	return container_of(gc, struct wcove_gpio, chip);
+}
+
+static inline int to_reg(int gpio, enum ctrl_register reg_type)
+{
+	int reg;
+
+	if (reg_type == CTRL_IN) {
+		if (gpio < 7)
+			reg = GPIO0P0CTLI + gpio;
+		else if (gpio < 11)
+			reg = GPIO1P0CTLI + (gpio % 7);
+		else
+			reg = GPIO2P0CTLI + (gpio % 11);
+	} else {
+		if (gpio < 7)
+			reg = GPIO0P0CTLO + gpio;
+		else if (gpio < 11)
+			reg = GPIO1P0CTLO + (gpio % 7);
+		else
+			reg = GPIO2P0CTLO + (gpio % 11);
+	}
+
+	return reg;
+}
+
+static void wcove_update_irq_mask(struct wcove_gpio *wg,
+					int gpio)
+{
+	u8 mirq = gpio < 7 ? MGPIOIRQ0 : MGPIOIRQ1;
+	int mask = BIT(gpio % 7);
+
+	if (wg->set_irq_mask)
+		regmap_update_bits(wg->regmap, mirq, mask, mask);
+	else
+		regmap_update_bits(wg->regmap, mirq, mask, 0);
+}
+
+static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
+{
+	int reg = to_reg(gpio, CTRL_IN);
+
+	regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt_value);
+}
+
+static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct wcove_gpio *wg = to_wg(chip);
+
+	if (gpio > WCOVE_VGPIO_NUM)
+		return 0;
+
+	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
+			    CTLO_INPUT_SET);
+}
+
+static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
+				    int value)
+{
+	struct wcove_gpio *wg = to_wg(chip);
+
+	if (gpio > WCOVE_VGPIO_NUM)
+		return 0;
+
+	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
+			    CTLO_OUTPUT_SET | value);
+}
+
+static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct wcove_gpio *wg = to_wg(chip);
+	int ret;
+	unsigned int val;
+
+	if (gpio > WCOVE_VGPIO_NUM)
+		return 0;
+
+	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &val);
+	if (ret)
+		return ret;
+
+	return val & 0x1;
+}
+
+static void wcove_gpio_set(struct gpio_chip *chip,
+				 unsigned int gpio, int value)
+{
+	struct wcove_gpio *wg = to_wg(chip);
+
+	if (gpio > WCOVE_VGPIO_NUM)
+		return;
+
+	if (value)
+		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
+	else
+		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 0);
+}
+
+static int wcove_irq_type(struct irq_data *data, unsigned int type)
+{
+	struct wcove_gpio *wg = to_wg(irq_data_get_irq_chip_data(data));
+
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		wg->intcnt_value = CTLI_INTCNT_DIS;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		wg->intcnt_value = CTLI_INTCNT_BE;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		wg->intcnt_value = CTLI_INTCNT_PE;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		wg->intcnt_value = CTLI_INTCNT_NE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	wg->update |= UPDATE_IRQ_TYPE;
+
+	return 0;
+}
+
+static void wcove_bus_lock(struct irq_data *data)
+{
+	struct wcove_gpio *wg = to_wg(irq_data_get_irq_chip_data(data));
+
+	mutex_lock(&wg->buslock);
+}
+
+static void wcove_bus_sync_unlock(struct irq_data *data)
+{
+	struct wcove_gpio *wg = to_wg(irq_data_get_irq_chip_data(data));
+	int gpio = data->hwirq;
+
+	if (wg->update & UPDATE_IRQ_TYPE)
+		wcove_update_irq_ctrl(wg, gpio);
+	if (wg->update & UPDATE_IRQ_MASK)
+		wcove_update_irq_mask(wg, gpio);
+	wg->update = 0;
+
+	mutex_unlock(&wg->buslock);
+}
+
+static void wcove_irq_unmask(struct irq_data *data)
+{
+	struct wcove_gpio *wg = to_wg(irq_data_get_irq_chip_data(data));
+
+	wg->set_irq_mask = false;
+	wg->update |= UPDATE_IRQ_MASK;
+}
+
+static void wcove_irq_mask(struct irq_data *data)
+{
+	struct wcove_gpio *wg = to_wg(irq_data_get_irq_chip_data(data));
+
+	wg->set_irq_mask = true;
+	wg->update |= UPDATE_IRQ_MASK;
+}
+
+static struct irq_chip wcove_irqchip = {
+	.name			= "Whiskey Cove",
+	.irq_mask		= wcove_irq_mask,
+	.irq_unmask		= wcove_irq_unmask,
+	.irq_set_type		= wcove_irq_type,
+	.irq_bus_lock		= wcove_bus_lock,
+	.irq_bus_sync_unlock	= wcove_bus_sync_unlock,
+};
+
+static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
+{
+	struct wcove_gpio *wg = data;
+	unsigned int p0, p1, virq;
+	int pending, gpio;
+
+	if (regmap_read(wg->regmap, GPIOIRQ0, &p0) ||
+	    regmap_read(wg->regmap, GPIOIRQ1, &p1))
+		return IRQ_NONE;
+
+	pending = p0 | (p1 << 8);
+
+	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
+		if (pending & BIT(gpio)) {
+			virq = irq_find_mapping(wg->chip.irqdomain, gpio);
+			handle_nested_irq(virq);
+		}
+	}
+
+	regmap_write(wg->regmap, GPIOIRQ0, p0);
+	regmap_write(wg->regmap, GPIOIRQ1, p1);
+
+	return IRQ_HANDLED;
+}
+
+static void wcove_gpio_dbg_show(struct seq_file *s,
+				      struct gpio_chip *chip)
+{
+	struct wcove_gpio *wg = to_wg(chip);
+	int gpio, offset;
+	unsigned int ctlo, ctli, mirq, irq;
+
+	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
+		regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
+		regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
+		regmap_read(wg->regmap, gpio < 7 ? MGPIOIRQ0 : MGPIOIRQ1,
+			    &mirq);
+		regmap_read(wg->regmap, gpio < 7 ? GPIOIRQ0 : GPIOIRQ1,
+			    &irq);
+
+		offset = gpio % 8;
+		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
+			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
+			   ctli & 0x1 ? "hi" : "lo",
+			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
+			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
+			   ctlo,
+			   mirq & BIT(offset) ? "mask  " : "unmask",
+			   irq & BIT(offset) ? "pending" : "       ");
+	}
+}
+
+static int wcove_gpio_probe(struct platform_device *pdev)
+{
+	int virq, retval, irq = platform_get_irq(pdev, 0);
+	struct wcove_gpio *wg;
+	struct device *dev = pdev->dev.parent;
+	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
+
+	if (irq < 0)
+		return irq;
+
+	wg = devm_kzalloc(&pdev->dev, sizeof(*wg), GFP_KERNEL);
+	if (!wg)
+		return -ENOMEM;
+
+	wg->regmap_irq_chip = pmic->irq_chip_data_level2;
+
+	platform_set_drvdata(pdev, wg);
+
+	mutex_init(&wg->buslock);
+	wg->chip.label = KBUILD_MODNAME;
+	wg->chip.direction_input = wcove_gpio_dir_in;
+	wg->chip.direction_output = wcove_gpio_dir_out;
+	wg->chip.get = wcove_gpio_get;
+	wg->chip.set = wcove_gpio_set;
+	wg->chip.base = -1;
+	wg->chip.ngpio = WCOVE_VGPIO_NUM;
+	wg->chip.can_sleep = true;
+	wg->chip.parent = dev;
+	wg->chip.dbg_show = wcove_gpio_dbg_show;
+	wg->regmap = pmic->regmap;
+
+	retval = gpiochip_add(&wg->chip);
+	if (retval) {
+		dev_warn(&pdev->dev, "add gpio chip error: %d\n", retval);
+		return retval;
+	}
+
+	gpiochip_irqchip_add(&wg->chip, &wcove_irqchip, 0,
+			     handle_simple_irq, IRQ_TYPE_NONE);
+
+	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
+	if (virq < 0) {
+		dev_err(&pdev->dev,
+				"failed to get virtual interrupt=%d\n", irq);
+		retval = virq;
+		goto out_remove_gpio;
+	}
+
+	retval = devm_request_threaded_irq(&pdev->dev, virq,
+			NULL, wcove_gpio_irq_handler,
+			IRQF_ONESHOT, pdev->name, wg);
+
+	if (retval) {
+		dev_warn(&pdev->dev, "request irq failed: %d, virq: %d\n",
+							retval, virq);
+		goto out_remove_gpio;
+	}
+
+	return 0;
+
+out_remove_gpio:
+	gpiochip_remove(&wg->chip);
+	return retval;
+}
+
+static int wcove_gpio_remove(struct platform_device *pdev)
+{
+	struct wcove_gpio *wg = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&wg->chip);
+	return 0;
+}
+
+static const struct platform_device_id pmic_gpio_id_table[] = {
+	{ "bxt_wcove_gpio", },
+};
+
+static struct platform_driver wcove_gpio_driver = {
+	.probe = wcove_gpio_probe,
+	.remove = wcove_gpio_remove,
+	.driver = {
+		.name = "wcove_gpio",
+	},
+	.id_table = pmic_gpio_id_table,
+};
+
+module_platform_driver(wcove_gpio_driver);
+
+MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@xxxxxxxxx>");
+MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

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