u-boot/drivers/gpio/tegra_gpio.c

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/*
* NVIDIA Tegra20 GPIO handling.
* (C) Copyright 2010-2012
* 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/tegra.h>
#include <asm/gpio.h>
enum {
TEGRA_CMD_INFO,
TEGRA_CMD_PORT,
TEGRA_CMD_OUTPUT,
TEGRA_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 'gpio' as GPIO (1) or SFPIO (0) */
static int get_config(unsigned gpio)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
int type;
u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
type = (u >> GPIO_BIT(gpio)) & 1;
debug("get_config: port = %d, bit = %d is %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
return type;
}
/* Config pin 'gpio' as GPIO or SFPIO, based on 'type' */
static void set_config(unsigned gpio, int type)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
debug("set_config: port = %d, bit = %d, %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), type ? "GPIO" : "SFPIO");
u = readl(&bank->gpio_config[GPIO_PORT(gpio)]);
if (type) /* GPIO */
u |= 1 << GPIO_BIT(gpio);
else
u &= ~(1 << GPIO_BIT(gpio));
writel(u, &bank->gpio_config[GPIO_PORT(gpio)]);
}
/* Return GPIO pin 'gpio' direction - 0 = input or 1 = output */
static int get_direction(unsigned gpio)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
int dir;
u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]);
dir = (u >> GPIO_BIT(gpio)) & 1;
debug("get_direction: port = %d, bit = %d, %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), dir ? "OUT" : "IN");
return dir;
}
/* Config GPIO pin 'gpio' as input or output (OE) as per 'output' */
static void set_direction(unsigned gpio, int output)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
debug("set_direction: port = %d, bit = %d, %s\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), output ? "OUT" : "IN");
u = readl(&bank->gpio_dir_out[GPIO_PORT(gpio)]);
if (output)
u |= 1 << GPIO_BIT(gpio);
else
u &= ~(1 << GPIO_BIT(gpio));
writel(u, &bank->gpio_dir_out[GPIO_PORT(gpio)]);
}
/* set GPIO pin 'gpio' output bit as 0 or 1 as per 'high' */
static void set_level(unsigned gpio, int high)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
u32 u;
debug("set_level: port = %d, bit %d == %d\n",
GPIO_FULLPORT(gpio), GPIO_BIT(gpio), high);
u = readl(&bank->gpio_out[GPIO_PORT(gpio)]);
if (high)
u |= 1 << GPIO_BIT(gpio);
else
u &= ~(1 << GPIO_BIT(gpio));
writel(u, &bank->gpio_out[GPIO_PORT(gpio)]);
}
/*
* Generic_GPIO primitives.
*/
int gpio_request(unsigned gpio, const char *label)
{
if (gpio >= MAX_NUM_GPIOS)
return -1;
if (label != NULL) {
strncpy(gpio_names[gpio].name, label, GPIO_NAME_SIZE);
gpio_names[gpio].name[GPIO_NAME_SIZE - 1] = '\0';
}
/* Configure as a GPIO */
set_config(gpio, 1);
return 0;
}
int gpio_free(unsigned gpio)
{
if (gpio >= MAX_NUM_GPIOS)
return -1;
gpio_names[gpio].name[0] = '\0';
/* Do not configure as input or change pin mux here */
return 0;
}
/* read GPIO OUT value of pin 'gpio' */
static int gpio_get_output_value(unsigned gpio)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
int val;
debug("gpio_get_output_value: pin = %d (port %d:bit %d)\n",
gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
val = readl(&bank->gpio_out[GPIO_PORT(gpio)]);
return (val >> GPIO_BIT(gpio)) & 1;
}
/* set GPIO pin 'gpio' as an input */
int gpio_direction_input(unsigned gpio)
{
debug("gpio_direction_input: pin = %d (port %d:bit %d)\n",
gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
/* Configure GPIO direction as input. */
set_direction(gpio, 0);
return 0;
}
/* set GPIO pin 'gpio' as an output, with polarity 'value' */
int gpio_direction_output(unsigned gpio, int value)
{
debug("gpio_direction_output: pin = %d (port %d:bit %d) = %s\n",
gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio),
value ? "HIGH" : "LOW");
/* Configure GPIO output value. */
set_level(gpio, value);
/* Configure GPIO direction as output. */
set_direction(gpio, 1);
return 0;
}
/* read GPIO IN value of pin 'gpio' */
int gpio_get_value(unsigned gpio)
{
struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
int val;
debug("gpio_get_value: pin = %d (port %d:bit %d)\n",
gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio));
val = readl(&bank->gpio_in[GPIO_PORT(gpio)]);
return (val >> GPIO_BIT(gpio)) & 1;
}
/* write GPIO OUT value to pin 'gpio' */
int gpio_set_value(unsigned gpio, int value)
{
debug("gpio_set_value: pin = %d (port %d:bit %d), value = %d\n",
gpio, GPIO_FULLPORT(gpio), GPIO_BIT(gpio), value);
/* Configure GPIO output value. */
set_level(gpio, value);
return 0;
}
/*
* Display Tegra GPIO information
*/
void gpio_info(void)
{
unsigned c;
int 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;
}
}