[U-Boot] [PATCH v4 04/13] drivers: gpio: add driver for Microchip PIC32 GPIO controller.

[Purna Chandra Mandal]

In PIC32 GPIO controller is part of PIC32 pin controller.
PIC32 has ten independently programmable ports and each with multiple pins.
Each of these pins can be configured and used as GPIO, provided they
are not in use for other peripherals.

Signed-off-by: Purna Chandra Mandal <purna.mandal at microchip.com>
Reviewed-by: Tom Rini <trini at konsulko.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>

---

Changes in v4:
- update kconfig dependency on DM && MACH_PIC32, and default y
- drop ioremap failure check
- return -EPERM if the pin is found in analog mode
- drop desc->offset setting in _gpio_xlate()

Changes in v3:
- add check on dev_get_addr()

Changes in v2: None

 drivers/gpio/Kconfig      |   7 ++
 drivers/gpio/Makefile     |   2 +-
 drivers/gpio/pic32_gpio.c | 174 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 182 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpio/pic32_gpio.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e60e9fd..845dc72 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 && MACH_PIC32
+	default y
+	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..499b4fa
--- /dev/null
+++ b/drivers/gpio/pic32_gpio.c
@@ -0,0 +1,174 @@
+/*
+ * 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>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Peripheral Pin Control */
+struct pic32_reg_port {
+	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_reg_port *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);
+
+	/* pin in analog mode ? */
+	if (readl(&priv->regs->ansel.raw) & BIT(offset))
+		return -EPERM;
+
+	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->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
+
+	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 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);
+	fdt_addr_t addr;
+	fdt_size_t size;
+	char *end;
+	int bank;
+
+	addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg", &size);
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	priv->regs = ioremap(addr, size);
+
+	uc_priv->gpio_count = MICROCHIP_GPIOS_PER_BANK;
+	/* extract bank name */
+	end = strrchr(dev->name, '@');
+	bank = trailing_strtoln(dev->name, end);
+	priv->name[0] = 'A' + bank;
+	uc_priv->bank_name = priv->name;
+
+	return 0;
+}
+
+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