[U-Boot] [PATCH v2 10/13] drivers: gpio: add driver for Microchip PIC32 GPIO controller.

[Purna Chandra Mandal]

PIC32 has ten independently programmable ports and each with multiple pins.
These pins can be configured and used as GPIO, if not use by any other
peripherals.

Signed-off-by: Purna Chandra Mandal <purna.mandal at microchip.com>
---

Changes in v2: None

 drivers/gpio/Kconfig      |   7 ++
 drivers/gpio/Makefile     |   2 +-
 drivers/gpio/pic32_gpio.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 172 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpio/pic32_gpio.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e60e9fd..13e9a6a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -83,4 +83,11 @@ config VYBRID_GPIO
 	help
 	  Say yes here to support Vybrid vf610 GPIOs.
 
+config PIC32_GPIO
+	bool "Microchip PIC32 GPIO driver"
+	depends on DM_GPIO
+	default y if MACH_PIC32
+	help
+	  Say yes here to support Microchip PIC32 GPIOs.
+
 endmenu
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index fb4fd25..845a6d4 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -46,4 +46,4 @@ obj-$(CONFIG_STM32_GPIO)	+= stm32_gpio.o
 obj-$(CONFIG_ZYNQ_GPIO)		+= zynq_gpio.o
 obj-$(CONFIG_VYBRID_GPIO)	+= vybrid_gpio.o
 obj-$(CONFIG_HIKEY_GPIO)	+= hi6220_gpio.o
-
+obj-$(CONFIG_PIC32_GPIO)	+= pic32_gpio.o
diff --git a/drivers/gpio/pic32_gpio.c b/drivers/gpio/pic32_gpio.c
new file mode 100644
index 0000000..69e3620
--- /dev/null
+++ b/drivers/gpio/pic32_gpio.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2015 Microchip Technology Inc
+ * Purna Chandra Mandal <purna.mandal at microchip.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+#include <linux/compat.h>
+#include <dt-bindings/gpio/gpio.h>
+#include <mach/pic32.h>
+
+/* Peripheral Pin Control */
+struct pic32_gpio_regs {
+	struct pic32_reg_atomic ansel;
+	struct pic32_reg_atomic tris;
+	struct pic32_reg_atomic port;
+	struct pic32_reg_atomic lat;
+	struct pic32_reg_atomic open_drain;
+	struct pic32_reg_atomic cnpu;
+	struct pic32_reg_atomic cnpd;
+	struct pic32_reg_atomic cncon;
+};
+
+enum {
+	MICROCHIP_GPIO_DIR_OUT,
+	MICROCHIP_GPIO_DIR_IN,
+	MICROCHIP_GPIOS_PER_BANK = 16,
+};
+
+struct pic32_gpio_priv {
+	struct pic32_gpio_regs *regs;
+	char name[2];
+};
+
+static int pic32_gpio_get_value(struct udevice *dev, unsigned offset)
+{
+	struct pic32_gpio_priv *priv = dev_get_priv(dev);
+
+	return !!(readl(&priv->regs->port.raw) & BIT(offset));
+}
+
+static int pic32_gpio_set_value(struct udevice *dev, unsigned offset,
+				int value)
+{
+	struct pic32_gpio_priv *priv = dev_get_priv(dev);
+	int mask = BIT(offset);
+
+	if (value)
+		writel(mask, &priv->regs->port.set);
+	else
+		writel(mask, &priv->regs->port.clr);
+
+	return 0;
+}
+
+static int pic32_gpio_direction(struct udevice *dev, unsigned offset)
+{
+	struct pic32_gpio_priv *priv = dev_get_priv(dev);
+
+	if (readl(&priv->regs->ansel.raw) & BIT(offset))
+		return -1;
+
+	if (readl(&priv->regs->tris.raw) & BIT(offset))
+		return MICROCHIP_GPIO_DIR_IN;
+	else
+		return MICROCHIP_GPIO_DIR_OUT;
+}
+
+static int pic32_gpio_direction_input(struct udevice *dev, unsigned offset)
+{
+	struct pic32_gpio_priv *priv = dev_get_priv(dev);
+	int mask = BIT(offset);
+
+	writel(mask, &priv->regs->ansel.clr);
+	writel(mask, &priv->regs->tris.set);
+
+	return 0;
+}
+
+static int pic32_gpio_direction_output(struct udevice *dev,
+				       unsigned offset, int value)
+{
+	struct pic32_gpio_priv *priv = dev_get_priv(dev);
+	int mask = BIT(offset);
+
+	writel(mask, &priv->regs->ansel.clr);
+	writel(mask, &priv->regs->tris.clr);
+
+	pic32_gpio_set_value(dev, offset, value);
+	return 0;
+}
+
+static int pic32_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
+			    struct fdtdec_phandle_args *args)
+{
+	desc->offset = args->args[0];
+	desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
+
+	return 0;
+}
+
+static int pic32_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct pic32_gpio_priv *priv = dev_get_priv(dev);
+	char *end;
+	int bank;
+
+	priv->regs = pic32_ioremap(dev_get_addr(dev));
+	uc_priv->gpio_count = MICROCHIP_GPIOS_PER_BANK;
+	end = strrchr(dev->name, '@');
+	bank = trailing_strtoln(dev->name, end);
+	priv->name[0] = 'A' + bank;
+	uc_priv->bank_name = priv->name;
+
+	return 0;
+}
+
+static int pic32_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+	int ret = GPIOF_UNUSED;
+
+	switch (pic32_gpio_direction(dev, offset)) {
+	case MICROCHIP_GPIO_DIR_OUT:
+		ret = GPIOF_OUTPUT;
+		break;
+	case MICROCHIP_GPIO_DIR_IN:
+		ret = GPIOF_INPUT;
+		break;
+	default:
+		ret = GPIOF_UNUSED;
+		break;
+	}
+	return ret;
+}
+
+static const struct dm_gpio_ops gpio_pic32_ops = {
+	.direction_input	= pic32_gpio_direction_input,
+	.direction_output	= pic32_gpio_direction_output,
+	.get_value		= pic32_gpio_get_value,
+	.set_value		= pic32_gpio_set_value,
+	.get_function		= pic32_gpio_get_function,
+	.xlate			= pic32_gpio_xlate,
+};
+
+static const struct udevice_id pic32_gpio_ids[] = {
+	{ .compatible = "microchip,pic32mzda-gpio" },
+	{ }
+};
+
+U_BOOT_DRIVER(gpio_pic32) = {
+	.name		= "gpio_pic32",
+	.id		= UCLASS_GPIO,
+	.of_match	= pic32_gpio_ids,
+	.ops		= &gpio_pic32_ops,
+	.probe		= pic32_gpio_probe,
+	.priv_auto_alloc_size	= sizeof(struct pic32_gpio_priv),
+};
-- 
1.8.3.1