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

Signed-off-by: Lucas Stach <[email protected]>
---
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..227a12f
--- /dev/null
+++ b/drivers/gpio/gpio-tegra.c
@@ -0,0 +1,214 @@
+/* *
+ * Copyright (C) 2010 Erik Gilling <[email protected]>, Google, Inc
+ * Copyright (C) 2013 Lucas Stach <[email protected]>
+ *
+ * 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);
-- 
1.8.1.2


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