GPIO: Tegra2: add GPIO driver for Tegra2

Signed-off-by: Tom Warren <twarren@nvidia.com>

1 files changed, 255 insertions, 0 deletions

diff --git a/drivers/gpio/tegra2_gpio.c b/drivers/gpio/tegra2_gpio.c
new file mode 100644
index 0000000..f686e80
--- /dev/null
+++ b/drivers/gpio/tegra2_gpio.c
@@ -0,0 +1,255 @@
+/*
+ * NVIDIA Tegra2 GPIO handling.
+ *  (C) Copyright 2010,2011
+ *  NVIDIA Corporation <www.nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * Based on (mostly copied from) kw_gpio.c based Linux 2.6 kernel driver.
+ * Tom Warren (twarren@nvidia.com)
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <asm/arch/tegra2.h>
+#include <asm/gpio.h>
+
+enum {
+	TEGRA2_CMD_INFO,
+	TEGRA2_CMD_PORT,
+	TEGRA2_CMD_OUTPUT,
+	TEGRA2_CMD_INPUT,
+};
+
+static struct gpio_names {
+	char name[GPIO_NAME_SIZE];
+} gpio_names[MAX_NUM_GPIOS];
+
+static char *get_name(int i)
+{
+	return *gpio_names[i].name ? gpio_names[i].name : "UNKNOWN";
+}
+
+/* Return config of pin 'gp' as GPIO (1) or SFPIO (0) */
+static int get_config(int gp)
+{
+	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
+	u32 u;
+	int type;
+
+	u = readl(&bank->gpio_config[GPIO_PORT(gp)]);
+	type =  (u >> GPIO_BIT(gp)) & 1;
+
+	debug("get_config: port = %d, bit = %d is %s\n",
+		GPIO_FULLPORT(gp), GPIO_BIT(gp), type ? "GPIO" : "SFPIO");
+
+	return type;
+}
+
+/* Config pin 'gp' as GPIO or SFPIO, based on 'type' */
+static void set_config(int gp, int type)
+{
+	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
+	u32 u;
+
+	debug("set_config: port = %d, bit = %d, %s\n",
+		GPIO_FULLPORT(gp), GPIO_BIT(gp), type ? "GPIO" : "SFPIO");
+
+	u = readl(&bank->gpio_config[GPIO_PORT(gp)]);
+	if (type)				/* GPIO */
+		u |= 1 << GPIO_BIT(gp);
+	else
+		u &= ~(1 << GPIO_BIT(gp));
+	writel(u, &bank->gpio_config[GPIO_PORT(gp)]);
+}
+
+/* Return GPIO pin 'gp' direction - 0 = input or 1 = output */
+static int get_direction(int gp)
+{
+	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
+	u32 u;
+	int dir;
+
+	u = readl(&bank->gpio_dir_out[GPIO_PORT(gp)]);
+	dir =  (u >> GPIO_BIT(gp)) & 1;
+
+	debug("get_direction: port = %d, bit = %d, %s\n",
+		GPIO_FULLPORT(gp), GPIO_BIT(gp), dir ? "OUT" : "IN");
+
+	return dir;
+}
+
+/* Config GPIO pin 'gp' as input or output (OE) as per 'output' */
+static void set_direction(int gp, int output)
+{
+	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
+	u32 u;
+
+	debug("set_direction: port = %d, bit = %d, %s\n",
+		GPIO_FULLPORT(gp), GPIO_BIT(gp), output ? "OUT" : "IN");
+
+	u = readl(&bank->gpio_dir_out[GPIO_PORT(gp)]);
+	if (output)
+		u |= 1 << GPIO_BIT(gp);
+	else
+		u &= ~(1 << GPIO_BIT(gp));
+	writel(u, &bank->gpio_dir_out[GPIO_PORT(gp)]);
+}
+
+/* set GPIO pin 'gp' output bit as 0 or 1 as per 'high' */
+static void set_level(int gp, int high)
+{
+	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
+	u32 u;
+
+	debug("set_level: port = %d, bit %d == %d\n",
+		GPIO_FULLPORT(gp), GPIO_BIT(gp), high);
+
+	u = readl(&bank->gpio_out[GPIO_PORT(gp)]);
+	if (high)
+		u |= 1 << GPIO_BIT(gp);
+	else
+		u &= ~(1 << GPIO_BIT(gp));
+	writel(u, &bank->gpio_out[GPIO_PORT(gp)]);
+}
+
+/*
+ * Generic_GPIO primitives.
+ */
+
+int gpio_request(int gp, const char *label)
+{
+	if (gp >= MAX_NUM_GPIOS)
+		return -1;
+
+	strncpy(gpio_names[gp].name, label, GPIO_NAME_SIZE);
+	gpio_names[gp].name[GPIO_NAME_SIZE - 1] = '\0';
+
+	/* Configure as a GPIO */
+	set_config(gp, 1);
+
+	return 0;
+}
+
+void gpio_free(int gp)
+{
+}
+
+/* read GPIO OUT value of pin 'gp' */
+static int gpio_get_output_value(int gp)
+{
+	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
+	int val;
+
+	debug("gpio_get_output_value: pin = %d (port %d:bit %d)\n",
+		gp, GPIO_FULLPORT(gp), GPIO_BIT(gp));
+
+	val = readl(&bank->gpio_out[GPIO_PORT(gp)]);
+
+	return (val >> GPIO_BIT(gp)) & 1;
+}
+
+void gpio_toggle_value(int gp)
+{
+	gpio_set_value(gp, !gpio_get_output_value(gp));
+}
+
+/* set GPIO pin 'gp' as an input */
+int gpio_direction_input(int gp)
+{
+	debug("gpio_direction_input: pin = %d (port %d:bit %d)\n",
+		gp, GPIO_FULLPORT(gp), GPIO_BIT(gp));
+
+	/* Configure GPIO direction as input. */
+	set_direction(gp, 0);
+
+	return 0;
+}
+
+/* set GPIO pin 'gp' as an output, with polarity 'value' */
+int gpio_direction_output(int gp, int value)
+{
+	debug("gpio_direction_output: pin = %d (port %d:bit %d) = %s\n",
+		gp, GPIO_FULLPORT(gp), GPIO_BIT(gp), value ? "HIGH" : "LOW");
+
+	/* Configure GPIO output value. */
+	set_level(gp, value);
+
+	/* Configure GPIO direction as output. */
+	set_direction(gp, 1);
+
+	return 0;
+}
+
+/* read GPIO IN value of pin 'gp' */
+int gpio_get_value(int gp)
+{
+	struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
+	int val;
+
+	debug("gpio_get_value: pin = %d (port %d:bit %d)\n",
+		gp, GPIO_FULLPORT(gp), GPIO_BIT(gp));
+
+	val = readl(&bank->gpio_in[GPIO_PORT(gp)]);
+
+	return (val >> GPIO_BIT(gp)) & 1;
+}
+
+/* write GPIO OUT value to pin 'gp' */
+void gpio_set_value(int gp, int value)
+{
+	debug("gpio_set_value: pin = %d (port %d:bit %d), value = %d\n",
+		gp, GPIO_FULLPORT(gp), GPIO_BIT(gp), value);
+
+	/* Configure GPIO output value. */
+	set_level(gp, value);
+}
+
+/*
+ * Display Tegra GPIO information
+ */
+void gpio_info(void)
+{
+	int c, type;
+
+	for (c = 0; c < MAX_NUM_GPIOS; c++) {
+		type = get_config(c);		/* GPIO, not SFPIO */
+		if (type) {
+			printf("GPIO_%d:\t%s is an %s, ", c,
+				get_name(c),
+				get_direction(c) ? "OUTPUT" : "INPUT");
+			if (get_direction(c))
+				printf("value = %d", gpio_get_output_value(c));
+			else
+				printf("value = %d", gpio_get_value(c));
+			printf("\n");
+		} else
+			continue;
+	}
+}