[PATCH v5 13/13] tegra: add GPIO controller driver

[Lucas Stach <dev@lynxeye.de>]

Taken from the Linux kernel, simplified and reworked to match barebox.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
---
v4: remove Tegra 30 parts for now
---
 arch/arm/Kconfig                        |   2 +
 arch/arm/dts/tegra20.dtsi               |  16 +++
 arch/arm/mach-tegra/include/mach/gpio.h |   1 +
 drivers/gpio/Kconfig                    |   7 ++
 drivers/gpio/Makefile                   |   1 +
 drivers/gpio/gpio-tegra.c               | 214 ++++++++++++++++++++++++++++++++
 6 files changed, 241 insertions(+)
 create mode 100644 arch/arm/mach-tegra/include/mach/gpio.h
 create mode 100644 drivers/gpio/gpio-tegra.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ed34d2c..0a4f821 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -142,6 +142,8 @@ config ARCH_TEGRA
 	select BUILTIN_DTB
 	select COMMON_CLK
 	select CLKDEV_LOOKUP
+	select GPIOLIB
+	select GPIO_TEGRA
 	select OFDEVICE
 	select OFTREE
 
diff --git a/arch/arm/dts/tegra20.dtsi b/arch/arm/dts/tegra20.dtsi
index 91858ec..b7d1e27 100644
--- a/arch/arm/dts/tegra20.dtsi
+++ b/arch/arm/dts/tegra20.dtsi
@@ -18,6 +18,22 @@
 		#clock-cells = <1>;
 	};
 
+	gpio: gpio {
+		compatible = "nvidia,tegra20-gpio";
+		reg = <0x6000d000 0x1000>;
+		interrupts = <0 32 0x04
+			      0 33 0x04
+			      0 34 0x04
+			      0 35 0x04
+			      0 55 0x04
+			      0 87 0x04
+			      0 89 0x04>;
+		#gpio-cells = <2>;
+		gpio-controller;
+		#interrupt-cells = <2>;
+		interrupt-controller;
+	};
+
 	pmc {
 		compatible = "nvidia,tegra20-pmc";
 		reg = <0x7000e400 0x400>;
diff --git a/arch/arm/mach-tegra/include/mach/gpio.h b/arch/arm/mach-tegra/include/mach/gpio.h
new file mode 100644
index 0000000..306ab4c
--- /dev/null
+++ b/arch/arm/mach-tegra/include/mach/gpio.h
@@ -0,0 +1 @@
+#include <asm-generic/gpio.h>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index ea07028..d5e0ed1 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -36,6 +36,13 @@ config GPIO_PL061
 config GPIO_STMPE
 	depends on MFD_STMPE
 	bool "STMPE GPIO Expander"
+
+config GPIO_TEGRA
+	bool "GPIO support for the Tegra SoCs"
+	depends on ARCH_TEGRA
+	help
+	  Say yes here to include the driver for the GPIO controller found on the
+	  Tegra line of SoCs.
 endmenu
 
 endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 00acb68..5dcb6c8 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_GPIO_CLPS711X)	+= gpio-clps711x.o
 obj-$(CONFIG_GPIO_GENERIC)	+= gpio-generic.o
 obj-$(CONFIG_GPIO_PL061)	+= gpio-pl061.o
 obj-$(CONFIG_GPIO_STMPE)	+= gpio-stmpe.o
+obj-$(CONFIG_GPIO_TEGRA)	+= gpio-tegra.o
diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
new file mode 100644
index 0000000..1e00f5e
--- /dev/null
+++ b/drivers/gpio/gpio-tegra.c
@@ -0,0 +1,214 @@
+/* *
+ * Copyright (C) 2010 Erik Gilling <konkers@google.com>, Google, Inc
+ * Copyright (C) 2013 Lucas Stach <l.stach@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <common.h>
+#include <gpio.h>
+#include <init.h>
+#include <io.h>
+#include <linux/err.h>
+
+#define GPIO_BANK(x)		((x) >> 5)
+#define GPIO_PORT(x)		(((x) >> 3) & 0x3)
+#define GPIO_BIT(x)		((x) & 0x7)
+
+#define GPIO_REG(x)		(GPIO_BANK(x) * config->bank_stride + \
+					GPIO_PORT(x) * 4)
+
+#define GPIO_CNF(x)		(GPIO_REG(x) + 0x00)
+#define GPIO_OE(x)		(GPIO_REG(x) + 0x10)
+#define GPIO_OUT(x)		(GPIO_REG(x) + 0x20)
+#define GPIO_IN(x)		(GPIO_REG(x) + 0x30)
+#define GPIO_INT_ENB(x)		(GPIO_REG(x) + 0x50)
+
+#define GPIO_MSK_CNF(x)		(GPIO_REG(x) + config->upper_offset + 0x00)
+#define GPIO_MSK_OE(x)		(GPIO_REG(x) + config->upper_offset + 0x10)
+#define GPIO_MSK_OUT(x)		(GPIO_REG(x) + config->upper_offset + 0X20)
+
+struct tegra_gpio_bank {
+	int bank;
+	int irq;
+};
+
+struct tegra_gpio_soc_config {
+	u32 bank_stride;
+	u32 upper_offset;
+	u32 bank_count;
+};
+
+static void __iomem *gpio_base;
+static struct tegra_gpio_soc_config *config;
+
+static inline void tegra_gpio_writel(u32 val, u32 reg)
+{
+	writel(val, gpio_base + reg);
+}
+
+static inline u32 tegra_gpio_readl(u32 reg)
+{
+	return readl(gpio_base + reg);
+}
+
+static int tegra_gpio_compose(int bank, int port, int bit)
+{
+	return (bank << 5) | ((port & 0x3) << 3) | (bit & 0x7);
+}
+
+static void tegra_gpio_mask_write(u32 reg, int gpio, int value)
+{
+	u32 val;
+
+	val = 0x100 << GPIO_BIT(gpio);
+	if (value)
+		val |= 1 << GPIO_BIT(gpio);
+	tegra_gpio_writel(val, reg);
+}
+
+static void tegra_gpio_enable(int gpio)
+{
+	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 1);
+}
+
+static void tegra_gpio_disable(int gpio)
+{
+	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 0);
+}
+
+static int tegra_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	return 0;
+}
+
+static void tegra_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	tegra_gpio_disable(offset);
+}
+
+static void tegra_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	tegra_gpio_mask_write(GPIO_MSK_OUT(offset), offset, value);
+}
+
+static int tegra_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	/* If gpio is in output mode then read from the out value */
+	if ((tegra_gpio_readl(GPIO_OE(offset)) >> GPIO_BIT(offset)) & 1) {
+		printf("GPIO output mode\n");
+		return (tegra_gpio_readl(GPIO_OUT(offset)) >>
+				GPIO_BIT(offset)) & 0x1;
+	}
+
+	printf("GPIO input mode\n");
+	return (tegra_gpio_readl(GPIO_IN(offset)) >> GPIO_BIT(offset)) & 0x1;
+}
+
+static int tegra_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 0);
+	tegra_gpio_enable(offset);
+	return 0;
+}
+
+static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+					int value)
+{
+	tegra_gpio_set(chip, offset, value);
+	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 1);
+	tegra_gpio_enable(offset);
+	return 0;
+}
+
+static struct gpio_ops tegra_gpio_ops = {
+	.request		= tegra_gpio_request,
+	.free			= tegra_gpio_free,
+	.direction_input	= tegra_gpio_direction_input,
+	.direction_output	= tegra_gpio_direction_output,
+	.get			= tegra_gpio_get,
+	.set			= tegra_gpio_set,
+};
+
+static struct gpio_chip tegra_gpio_chip = {
+	.ops	= &tegra_gpio_ops,
+	.base	= 0,
+};
+
+static int tegra_gpio_probe(struct device_d *dev)
+{
+	int i, j, ret;
+
+	ret = dev_get_drvdata(dev, (unsigned long *)&config);
+	if (ret) {
+		dev_err(dev, "dev_get_drvdata failed: %d\n", ret);
+		return ret;
+	}
+
+	gpio_base = dev_request_mem_region(dev, 0);
+	if (!gpio_base) {
+		dev_err(dev, "could not get memory region\n");
+		return -ENODEV;
+	}
+
+	for (i = 0; i < config->bank_count; i++) {
+		for (j = 0; j < 4; j++) {
+			int gpio = tegra_gpio_compose(i, j, 0);
+			tegra_gpio_writel(0x00, GPIO_INT_ENB(gpio));
+		}
+	}
+
+	tegra_gpio_chip.ngpio = config->bank_count * 32;
+	tegra_gpio_chip.dev = dev;
+
+	gpiochip_add(&tegra_gpio_chip);
+
+	return 0;
+}
+
+static struct tegra_gpio_soc_config tegra20_gpio_config = {
+	.bank_stride = 0x80,
+	.upper_offset = 0x800,
+	.bank_count = 7,
+};
+
+static struct platform_device_id tegra_gpio_ids[] = {
+	{
+		.name = "tegra20-gpio",
+		.driver_data = (unsigned long)&tegra20_gpio_config,
+	}, {
+		/* sentinel */
+	},
+};
+
+static __maybe_unused struct of_device_id tegra_gpio_dt_ids[] = {
+	{
+		.compatible = "nvidia,tegra20-gpio",
+		.data = (unsigned long)&tegra20_gpio_config
+	}, {
+		/* sentinel */
+	},
+};
+
+static struct driver_d tegra_gpio_driver = {
+	.name		= "tegra-gpio",
+	.id_table	= tegra_gpio_ids,
+	.of_compatible	= DRV_OF_COMPAT(tegra_gpio_dt_ids),
+	.probe		= tegra_gpio_probe,
+};
+
+static int __init tegra_gpio_init(void)
+{
+	return platform_driver_register(&tegra_gpio_driver);
+}
+coredevice_initcall(tegra_gpio_init);
-- 
1.8.1.4


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