arm: vt8500: gpio: Devicetree support for arch-vt8500

Converted the existing arch-vt8500 gpio to a platform_device.
Added support for WM8505 and WM8650 GPIO controllers.
Replaced existing readl/writel calls with _relaxed variants.
Replaced existing unsigned variables with u32 to match register size.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 323 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index ba7926f5c099..a00b828b1643 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -183,6 +183,12 @@ config GPIO_STA2X11
 	  Say yes here to support the STA2x11/ConneXt GPIO device.
 	  The GPIO module has 128 GPIO pins with alternate functions.
 
+config GPIO_VT8500
+	bool "VIA/Wondermedia SoC GPIO Support"
+	depends on ARCH_VT8500
+	help
+	  Say yes here to support the VT8500/WM8505/WM8650 GPIO controller.
+
 config GPIO_XILINX
 	bool "Xilinx GPIO support"
 	depends on PPC_OF || MICROBLAZE
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 153caceeb053..a288142ad998 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_GPIO_TPS65912)	+= gpio-tps65912.o
 obj-$(CONFIG_GPIO_TWL4030)	+= gpio-twl4030.o
 obj-$(CONFIG_GPIO_UCB1400)	+= gpio-ucb1400.o
 obj-$(CONFIG_GPIO_VR41XX)	+= gpio-vr41xx.o
+obj-$(CONFIG_GPIO_VT8500)	+= gpio-vt8500.o
 obj-$(CONFIG_GPIO_VX855)	+= gpio-vx855.o
 obj-$(CONFIG_GPIO_WM831X)	+= gpio-wm831x.o
 obj-$(CONFIG_GPIO_WM8350)	+= gpio-wm8350.o
diff --git a/drivers/gpio/gpio-vt8500.c b/drivers/gpio/gpio-vt8500.c
new file mode 100644
index 000000000000..bcd8e4aa7c7d
--- /dev/null
+++ b/drivers/gpio/gpio-vt8500.c
@@ -0,0 +1,316 @@
+/* drivers/gpio/gpio-vt8500.c
+ *
+ * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
+ * Based on arch/arm/mach-vt8500/gpio.c:
+ * - Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/module.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+
+/*
+	We handle GPIOs by bank, each bank containing up to 32 GPIOs covered
+	by one set of registers (although not all may be valid).
+
+	Because different SoC's have different register offsets, we pass the
+	register offsets as data in vt8500_gpio_dt_ids[].
+
+	A value of NO_REG is used to indicate that this register is not
+	supported. Only used for ->en at the moment.
+*/
+
+#define NO_REG	0xFFFF
+
+/*
+ * struct vt8500_gpio_bank_regoffsets
+ * @en: offset to enable register of the bank
+ * @dir: offset to direction register of the bank
+ * @data_out: offset to the data out register of the bank
+ * @data_in: offset to the data in register of the bank
+ * @ngpio: highest valid pin in this bank
+ */
+
+struct vt8500_gpio_bank_regoffsets {
+	unsigned int	en;
+	unsigned int	dir;
+	unsigned int	data_out;
+	unsigned int	data_in;
+	unsigned char	ngpio;
+};
+
+struct vt8500_gpio_data {
+	unsigned int				num_banks;
+	struct vt8500_gpio_bank_regoffsets	banks[];
+};
+
+#define VT8500_BANK(__en, __dir, __out, __in, __ngpio)		\
+{								\
+	.en = __en,						\
+	.dir = __dir,						\
+	.data_out = __out,					\
+	.data_in = __in,					\
+	.ngpio = __ngpio,					\
+}
+
+static struct vt8500_gpio_data vt8500_data = {
+	.num_banks	= 7,
+	.banks	= {
+		VT8500_BANK(0x00, 0x20, 0x40, 0x60, 26),
+		VT8500_BANK(0x04, 0x24, 0x44, 0x64, 28),
+		VT8500_BANK(0x08, 0x28, 0x48, 0x68, 31),
+		VT8500_BANK(0x0C, 0x2C, 0x4C, 0x6C, 19),
+		VT8500_BANK(0x10, 0x30, 0x50, 0x70, 19),
+		VT8500_BANK(0x14, 0x34, 0x54, 0x74, 23),
+		VT8500_BANK(NO_REG, 0x3C, 0x5C, 0x7C, 9),
+	},
+};
+
+static struct vt8500_gpio_data wm8505_data = {
+	.num_banks	= 10,
+	.banks	= {
+		VT8500_BANK(0x40, 0x68, 0x90, 0xB8, 8),
+		VT8500_BANK(0x44, 0x6C, 0x94, 0xBC, 32),
+		VT8500_BANK(0x48, 0x70, 0x98, 0xC0, 6),
+		VT8500_BANK(0x4C, 0x74, 0x9C, 0xC4, 16),
+		VT8500_BANK(0x50, 0x78, 0xA0, 0xC8, 25),
+		VT8500_BANK(0x54, 0x7C, 0xA4, 0xCC, 5),
+		VT8500_BANK(0x58, 0x80, 0xA8, 0xD0, 5),
+		VT8500_BANK(0x5C, 0x84, 0xAC, 0xD4, 12),
+		VT8500_BANK(0x60, 0x88, 0xB0, 0xD8, 16),
+		VT8500_BANK(0x64, 0x8C, 0xB4, 0xDC, 22),
+	},
+};
+
+/*
+ * No information about which bits are valid so we just make
+ * them all available until its figured out.
+ */
+static struct vt8500_gpio_data wm8650_data = {
+	.num_banks	= 9,
+	.banks	= {
+		VT8500_BANK(0x40, 0x80, 0xC0, 0x00, 32),
+		VT8500_BANK(0x44, 0x84, 0xC4, 0x04, 32),
+		VT8500_BANK(0x48, 0x88, 0xC8, 0x08, 32),
+		VT8500_BANK(0x4C, 0x8C, 0xCC, 0x0C, 32),
+		VT8500_BANK(0x50, 0x90, 0xD0, 0x10, 32),
+		VT8500_BANK(0x54, 0x94, 0xD4, 0x14, 32),
+		VT8500_BANK(0x58, 0x98, 0xD8, 0x18, 32),
+		VT8500_BANK(0x5C, 0x9C, 0xDC, 0x1C, 32),
+		VT8500_BANK(0x7C, 0xBC, 0xFC, 0x3C, 32),
+	},
+};
+
+struct vt8500_gpio_chip {
+	struct gpio_chip		chip;
+
+	const struct vt8500_gpio_bank_regoffsets *regs;
+	void __iomem	*base;
+};
+
+
+#define to_vt8500(__chip) container_of(__chip, struct vt8500_gpio_chip, chip)
+
+static int vt8500_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	u32 val;
+	struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip);
+
+	if (vt8500_chip->regs->en == NO_REG)
+		return 0;
+
+	val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->en);
+	val |= BIT(offset);
+	writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->en);
+
+	return 0;
+}
+
+static void vt8500_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip);
+	u32 val;
+
+	if (vt8500_chip->regs->en == NO_REG)
+		return;
+
+	val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->en);
+	val &= ~BIT(offset);
+	writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->en);
+}
+
+static int vt8500_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip);
+
+	u32 val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->dir);
+	val &= ~BIT(offset);
+	writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->dir);
+
+	return 0;
+}
+
+static int vt8500_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+								int value)
+{
+	struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip);
+
+	u32 val = readl_relaxed(vt8500_chip->base + vt8500_chip->regs->dir);
+	val |= BIT(offset);
+	writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->dir);
+
+	if (value) {
+		val = readl_relaxed(vt8500_chip->base +
+						vt8500_chip->regs->data_out);
+		val |= BIT(offset);
+		writel_relaxed(val, vt8500_chip->base +
+						vt8500_chip->regs->data_out);
+	}
+	return 0;
+}
+
+static int vt8500_gpio_get_value(struct gpio_chip *chip, unsigned offset)
+{
+	struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip);
+
+	return (readl_relaxed(vt8500_chip->base + vt8500_chip->regs->data_in) >>
+								offset) & 1;
+}
+
+static void vt8500_gpio_set_value(struct gpio_chip *chip, unsigned offset,
+								int value)
+{
+	struct vt8500_gpio_chip *vt8500_chip = to_vt8500(chip);
+
+	u32 val = readl_relaxed(vt8500_chip->base +
+						vt8500_chip->regs->data_out);
+	if (value)
+		val |= BIT(offset);
+	else
+		val &= ~BIT(offset);
+
+	writel_relaxed(val, vt8500_chip->base + vt8500_chip->regs->data_out);
+}
+
+static int vt8500_of_xlate(struct gpio_chip *gc,
+			    const struct of_phandle_args *gpiospec, u32 *flags)
+{
+	/* bank if specificed in gpiospec->args[0] */
+	if (flags)
+		*flags = gpiospec->args[2];
+
+	return gpiospec->args[1];
+}
+
+static int vt8500_add_chips(struct platform_device *pdev, void __iomem *base,
+				const struct vt8500_gpio_data *data)
+{
+	struct vt8500_gpio_chip *vtchip;
+	struct gpio_chip *chip;
+	int i;
+	int pin_cnt = 0;
+
+	vtchip = devm_kzalloc(&pdev->dev,
+			sizeof(struct vt8500_gpio_chip) * data->num_banks,
+			GFP_KERNEL);
+	if (!vtchip) {
+		pr_err("%s: failed to allocate chip memory\n", __func__);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < data->num_banks; i++) {
+		vtchip[i].base = base;
+		vtchip[i].regs = &data->banks[i];
+
+		chip = &vtchip[i].chip;
+
+		chip->of_xlate = vt8500_of_xlate;
+		chip->of_gpio_n_cells = 3;
+		chip->of_node = pdev->dev.of_node;
+
+		chip->request = vt8500_gpio_request;
+		chip->free = vt8500_gpio_free;
+		chip->direction_input = vt8500_gpio_direction_input;
+		chip->direction_output = vt8500_gpio_direction_output;
+		chip->get = vt8500_gpio_get_value;
+		chip->set = vt8500_gpio_set_value;
+		chip->can_sleep = 0;
+		chip->base = pin_cnt;
+		chip->ngpio = data->banks[i].ngpio;
+
+		pin_cnt += data->banks[i].ngpio;
+
+		gpiochip_add(chip);
+	}
+	return 0;
+}
+
+static struct of_device_id vt8500_gpio_dt_ids[] = {
+	{ .compatible = "via,vt8500-gpio", .data = &vt8500_data, },
+	{ .compatible = "wm,wm8505-gpio", .data = &wm8505_data, },
+	{ .compatible = "wm,wm8650-gpio", .data = &wm8650_data, },
+	{ /* Sentinel */ },
+};
+
+static int __devinit vt8500_gpio_probe(struct platform_device *pdev)
+{
+	void __iomem *gpio_base;
+	struct device_node *np;
+	const struct of_device_id *of_id =
+				of_match_device(vt8500_gpio_dt_ids, &pdev->dev);
+
+	if (!of_id) {
+		dev_err(&pdev->dev, "Failed to find gpio controller\n");
+		return -ENODEV;
+	}
+
+	np = pdev->dev.of_node;
+	if (!np) {
+		dev_err(&pdev->dev, "Missing GPIO description in devicetree\n");
+		return -EFAULT;
+	}
+
+	gpio_base = of_iomap(np, 0);
+	if (!gpio_base) {
+		dev_err(&pdev->dev, "Unable to map GPIO registers\n");
+		of_node_put(np);
+		return -ENOMEM;
+	}
+
+	vt8500_add_chips(pdev, gpio_base, of_id->data);
+
+	return 0;
+}
+
+static struct platform_driver vt8500_gpio_driver = {
+	.probe		= vt8500_gpio_probe,
+	.driver		= {
+		.name	= "vt8500-gpio",
+		.owner	= THIS_MODULE,
+		.of_match_table = vt8500_gpio_dt_ids,
+	},
+};
+
+module_platform_driver(vt8500_gpio_driver);
+
+MODULE_DESCRIPTION("VT8500 GPIO Driver");
+MODULE_AUTHOR("Tony Prisk <linux@prisktech.co.nz>");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(of, vt8500_gpio_dt_ids);