[PATCH v4 4/7] pinctrl: armada-37xx: Add gpio support

[Gregory CLEMENT <gregory.clement@free-electrons.com>]

GPIO management is pretty simple and is part of the same IP than the pin
controller for the Armada 37xx SoCs.  This patch adds the GPIO support to
the pinctrl-armada-37xx.c file, it also allows sharing common functions
between the gpiolib and the pinctrl drivers.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
 drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 128 ++++++++++++++++++---
 1 file changed, 114 insertions(+), 14 deletions(-)

diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
index 8b769d77db22..5c96f5558310 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
@@ -10,6 +10,7 @@
  * without any warranty of any kind, whether express or implied.
  */
 
+#include <linux/gpio/driver.h>
 #include <linux/mfd/syscon.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
@@ -24,6 +25,8 @@
 #include "../pinctrl-utils.h"
 
 #define OUTPUT_EN	0x0
+#define INPUT_VAL	0x10
+#define OUTPUT_VAL	0x18
 #define OUTPUT_CTL	0x20
 #define SELECTION	0x30
 
@@ -74,6 +77,7 @@ struct armada_37xx_pinctrl {
 	struct regmap			*regmap;
 	const struct armada_37xx_pin_data	*data;
 	struct device			*dev;
+	struct gpio_chip		gpio_chip;
 	struct pinctrl_desc		pctl;
 	struct pinctrl_dev		*pctl_dev;
 	struct armada_37xx_pin_group	*groups;
@@ -178,6 +182,16 @@ const struct armada_37xx_pin_data armada_37xx_pin_sb = {
 	.ngroups = ARRAY_SIZE(armada_37xx_sb_groups),
 };
 
+static inline void armada_37xx_update_reg(unsigned int *reg,
+					  unsigned int offset)
+{
+	/* We never have more than 2 registers */
+	if (offset >= GPIO_PER_REG) {
+		offset -= GPIO_PER_REG;
+		*reg += sizeof(u32);
+	}
+}
+
 static int armada_37xx_get_func_reg(struct armada_37xx_pin_group *grp,
 				    const char *func)
 {
@@ -332,49 +346,88 @@ static int armada_37xx_pmx_set(struct pinctrl_dev *pctldev,
 	return armada_37xx_pmx_set_by_name(pctldev, name, grp);
 }
 
-static int armada_37xx_pmx_direction_input(struct armada_37xx_pinctrl *info,
-					   unsigned int offset)
+static int armada_37xx_gpio_direction_input(struct gpio_chip *chip,
+					    unsigned int offset)
 {
+	struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
 	unsigned int reg = OUTPUT_EN;
 	unsigned int mask;
 
-	if (offset >= GPIO_PER_REG) {
-		offset -= GPIO_PER_REG;
-		reg += sizeof(u32);
-	}
+	armada_37xx_update_reg(&reg, offset);
 	mask = BIT(offset);
 
 	return regmap_update_bits(info->regmap, reg, mask, 0);
 }
 
-static int armada_37xx_pmx_direction_output(struct armada_37xx_pinctrl *info,
-					    unsigned int offset, int value)
+static int armada_37xx_gpio_get_direction(struct gpio_chip *chip,
+					  unsigned int offset)
 {
+	struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
+	unsigned int reg = OUTPUT_EN;
+	unsigned int val, mask;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+	regmap_read(info->regmap, reg, &val);
+
+	return !(val & mask);
+}
+
+static int armada_37xx_gpio_direction_output(struct gpio_chip *chip,
+					     unsigned int offset, int value)
+{
+	struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
 	unsigned int reg = OUTPUT_EN;
 	unsigned int mask;
 
-	if (offset >= GPIO_PER_REG) {
-		offset -= GPIO_PER_REG;
-		reg += sizeof(u32);
-	}
+	armada_37xx_update_reg(&reg, offset);
 	mask = BIT(offset);
 
 	return regmap_update_bits(info->regmap, reg, mask, mask);
 }
 
+static int armada_37xx_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
+	unsigned int reg = INPUT_VAL;
+	unsigned int val, mask;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+
+	regmap_read(info->regmap, reg, &val);
+
+	return (val & mask) != 0;
+}
+
+static void armada_37xx_gpio_set(struct gpio_chip *chip, unsigned int offset,
+				 int value)
+{
+	struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
+	unsigned int reg = OUTPUT_VAL;
+	unsigned int mask, val;
+
+	armada_37xx_update_reg(&reg, offset);
+	mask = BIT(offset);
+	val = value ? mask : 0;
+
+	regmap_update_bits(info->regmap, reg, mask, val);
+}
+
 static int armada_37xx_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
 					      struct pinctrl_gpio_range *range,
 					      unsigned int offset, bool input)
 {
 	struct armada_37xx_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	struct gpio_chip *chip = range->gc;
 
 	dev_dbg(info->dev, "gpio_direction for pin %u as %s-%d to %s\n",
 		offset, range->name, offset, input ? "input" : "output");
 
 	if (input)
-		armada_37xx_pmx_direction_input(info, offset);
+		armada_37xx_gpio_direction_input(chip, offset);
 	else
-		armada_37xx_pmx_direction_output(info, offset, 0);
+		armada_37xx_gpio_direction_output(chip, offset, 0);
 
 	return 0;
 }
@@ -404,6 +457,49 @@ static const struct pinmux_ops armada_37xx_pmx_ops = {
 	.gpio_set_direction	= armada_37xx_pmx_gpio_set_direction,
 };
 
+static const struct gpio_chip armada_37xx_gpiolib_chip = {
+	.request = gpiochip_generic_request,
+	.free = gpiochip_generic_free,
+	.set = armada_37xx_gpio_set,
+	.get = armada_37xx_gpio_get,
+	.get_direction	= armada_37xx_gpio_get_direction,
+	.direction_input = armada_37xx_gpio_direction_input,
+	.direction_output = armada_37xx_gpio_direction_output,
+	.owner = THIS_MODULE,
+};
+
+static int armada_37xx_gpiochip_register(struct platform_device *pdev,
+					struct armada_37xx_pinctrl *info)
+{
+	struct device_node *np;
+	struct gpio_chip *gc;
+	int ret = -ENODEV;
+
+	for_each_child_of_node(info->dev->of_node, np) {
+		if (of_find_property(np, "gpio-controller", NULL)) {
+			ret = 0;
+			break;
+		}
+	};
+	if (ret)
+		return ret;
+
+	info->gpio_chip = armada_37xx_gpiolib_chip;
+
+	gc = &info->gpio_chip;
+	gc->ngpio = info->data->nr_pins;
+	gc->parent = &pdev->dev;
+	gc->base = -1;
+	gc->of_node = np;
+	gc->label = info->data->name;
+
+	ret = devm_gpiochip_add_data(&pdev->dev, gc, info);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 /**
  * armada_37xx_add_function() - Add a new function to the list
  * @funcs: array of function to add the new one
@@ -632,6 +728,10 @@ static int __init armada_37xx_pinctrl_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = armada_37xx_gpiochip_register(pdev, info);
+	if (ret)
+		return ret;
+
 	platform_set_drvdata(pdev, info);
 
 	return 0;
-- 
git-series 0.9.1