[U-Boot] [PATCH V3 1/3] gpio: Add DW APB GPIO driver

[Marek Vasut]

Add driver for the DesignWare APB GPIO IP block.
This driver is DM capable and probes from DT.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Simon Glass <sjg at chromium.org>
---
 drivers/gpio/Kconfig      |  10 +++
 drivers/gpio/Makefile     |   1 +
 drivers/gpio/dwapb_gpio.c | 167 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 178 insertions(+)
 create mode 100644 drivers/gpio/dwapb_gpio.c

V2: Obtain the bank name from the "bank-name" property instead.
V3: Tweak the description, replace ENXIO with EINVAL, fix Simon's comments.

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 5934597..8db48d1 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -14,6 +14,16 @@ config DM_GPIO
 	  particular GPIOs that they provide. The uclass interface
 	  is defined in include/asm-generic/gpio.h.
 
+config DWAPB_GPIO
+	bool "DWAPB GPIO driver"
+	depends on DM && DM_GPIO
+	default n
+	help
+	  Support for the Designware APB GPIO driver. This driver can
+	  be probed only from device tree. Each DW APB GPIO controller
+	  can contain multiple GPIO banks, use the "bank-name" property
+	  in the OF to select reasonable name for each bank.
+
 config LPC32XX_GPIO
 	bool "LPC32XX GPIO driver"
 	depends on DM
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 26f2574..ba18594 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -6,6 +6,7 @@
 #
 
 ifndef CONFIG_SPL_BUILD
+obj-$(CONFIG_DWAPB_GPIO)	+= dwapb_gpio.o
 obj-$(CONFIG_AXP_GPIO)		+= axp_gpio.o
 endif
 obj-$(CONFIG_DM_GPIO)		+= gpio-uclass.o
diff --git a/drivers/gpio/dwapb_gpio.c b/drivers/gpio/dwapb_gpio.c
new file mode 100644
index 0000000..cee93e8
--- /dev/null
+++ b/drivers/gpio/dwapb_gpio.c
@@ -0,0 +1,167 @@
+/*
+ * (C) Copyright 2015 Marek Vasut <marex at denx.de>
+ *
+ * DesignWare APB GPIO driver
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <malloc.h>
+#include <asm/arch/gpio.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/root.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define GPIO_SWPORTA_DR		0x00
+#define GPIO_SWPORTA_DDR	0x04
+#define GPIO_INTEN		0x30
+#define GPIO_INTMASK		0x34
+#define GPIO_INTTYPE_LEVEL	0x38
+#define GPIO_INT_POLARITY	0x3c
+#define GPIO_INTSTATUS		0x40
+#define GPIO_PORTA_DEBOUNCE	0x48
+#define GPIO_PORTA_EOI		0x4c
+#define GPIO_EXT_PORTA		0x50
+
+struct gpio_dwapb_platdata {
+	const char	*name;
+	int		bank;
+	int		pins;
+	fdt_addr_t	base;
+};
+
+static int dwapb_gpio_direction_input(struct udevice *dev, unsigned pin)
+{
+	struct gpio_dwapb_platdata *plat = dev_get_platdata(dev);
+
+	clrbits_le32(plat->base + GPIO_SWPORTA_DDR, 1 << pin);
+	return 0;
+}
+
+static int dwapb_gpio_direction_output(struct udevice *dev, unsigned pin,
+				     int val)
+{
+	struct gpio_dwapb_platdata *plat = dev_get_platdata(dev);
+
+	setbits_le32(plat->base + GPIO_SWPORTA_DDR, 1 << pin);
+
+	if (val)
+		setbits_le32(plat->base + GPIO_SWPORTA_DR, 1 << pin);
+	else
+		clrbits_le32(plat->base + GPIO_SWPORTA_DR, 1 << pin);
+
+	return 0;
+}
+
+static int dwapb_gpio_get_value(struct udevice *dev, unsigned pin)
+{
+	struct gpio_dwapb_platdata *plat = dev_get_platdata(dev);
+	return !!(readl(plat->base + GPIO_EXT_PORTA) & (1 << pin));
+}
+
+
+static int dwapb_gpio_set_value(struct udevice *dev, unsigned pin, int val)
+{
+	struct gpio_dwapb_platdata *plat = dev_get_platdata(dev);
+
+	if (val)
+		setbits_le32(plat->base + GPIO_SWPORTA_DR, 1 << pin);
+	else
+		clrbits_le32(plat->base + GPIO_SWPORTA_DR, 1 << pin);
+
+	return 0;
+}
+
+static const struct dm_gpio_ops gpio_dwapb_ops = {
+	.direction_input	= dwapb_gpio_direction_input,
+	.direction_output	= dwapb_gpio_direction_output,
+	.get_value		= dwapb_gpio_get_value,
+	.set_value		= dwapb_gpio_set_value,
+};
+
+static int gpio_dwapb_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *priv = dev_get_uclass_priv(dev);
+	struct gpio_dwapb_platdata *plat = dev->platdata;
+
+	if (!plat)
+		return 0;
+
+	priv->gpio_count = plat->pins;
+	priv->bank_name = plat->name;
+
+	return 0;
+}
+
+static int gpio_dwapb_bind(struct udevice *dev)
+{
+	struct gpio_dwapb_platdata *plat = dev_get_platdata(dev);
+	const void *blob = gd->fdt_blob;
+	struct udevice *subdev;
+	fdt_addr_t base;
+	int ret, node, bank = 0;
+
+	/* If this is a child device, there is nothing to do here */
+	if (plat)
+		return 0;
+
+	base = fdtdec_get_addr(blob, dev->of_offset, "reg");
+	if (base == FDT_ADDR_T_NONE) {
+		debug("Can't get the GPIO register base address\n");
+		return -EINVAL;
+	}
+
+	for (node = fdt_first_subnode(blob, dev->of_offset);
+	     node > 0;
+	     node = fdt_next_subnode(blob, node)) {
+		if (!fdtdec_get_bool(blob, node, "gpio-controller"))
+			continue;
+
+		plat = NULL;
+		plat = calloc(1, sizeof(*plat));
+		if (!plat)
+			return -ENOMEM;
+
+		plat->base = base;
+		plat->bank = bank;
+		plat->pins = fdtdec_get_int(blob, node, "snps,nr-gpios", 0);
+		ret = fdt_get_string(blob, node, "bank-name", &plat->name);
+		if (ret)
+			goto err;
+
+		ret = device_bind(dev, dev->driver, plat->name,
+				  plat, -1, &subdev);
+		if (ret)
+			goto err;
+
+		subdev->of_offset = node;
+		bank++;
+	}
+
+	return 0;
+
+err:
+	free(plat);
+	return ret;
+}
+
+static const struct udevice_id gpio_dwapb_ids[] = {
+	{ .compatible = "snps,dw-apb-gpio" },
+	{ }
+};
+
+U_BOOT_DRIVER(gpio_dwapb) = {
+	.name		= "gpio-dwapb",
+	.id		= UCLASS_GPIO,
+	.of_match	= gpio_dwapb_ids,
+	.ops		= &gpio_dwapb_ops,
+	.bind		= gpio_dwapb_bind,
+	.probe		= gpio_dwapb_probe,
+};
-- 
2.1.4