Commit 8d30fcd9 authored by Simon Glass's avatar Simon Glass Committed by Mike Frysinger
Browse files

sandbox: gpio: add basic driver for simulating GPIOs



This provides a way of simulating GPIOs by setting values which are seen
by the normal gpio_get/set_value() calls.
Signed-off-by: default avatarSimon Glass <sjg@chromium.org>
Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
parent d9165153
/*
* This is the interface to the sandbox GPIO driver for test code which
* wants to change the GPIO values reported to U-Boot.
*
* Copyright (c) 2011 The Chromium OS Authors.
* 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
*/
#ifndef __ASM_SANDBOX_GPIO_H
#define __ASM_SANDBOX_GPIO_H
/*
* We use the generic interface, and add a back-channel.
*
* The back-channel functions are declared in this file. They should not be used
* except in test code.
*
* Test code can, for example, call sandbox_gpio_set_value() to set the value of
* a simulated GPIO. From then on, normal code in U-Boot will see this new
* value when it calls gpio_get_value().
*
* NOTE: DO NOT use the functions in this file except in test code!
*/
#include <asm-generic/gpio.h>
/**
* Return the simulated value of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @return -1 on error, 0 if GPIO is low, >0 if high
*/
int sandbox_gpio_get_value(unsigned gp);
/**
* Set the simulated value of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @param value value to set (0 for low, non-zero for high)
* @return -1 on error, 0 if ok
*/
int sandbox_gpio_set_value(unsigned gp, int value);
/**
* Return the simulated direction of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @return -1 on error, 0 if GPIO is input, >0 if output
*/
int sandbox_gpio_get_direction(unsigned gp);
/**
* Set the simulated direction of a GPIO (used only in sandbox test code)
*
* @param gp GPIO number
* @param output 0 to set as input, 1 to set as output
* @return -1 on error, 0 if ok
*/
int sandbox_gpio_set_direction(unsigned gp, int output);
/* Display information about each GPIO */
void gpio_info(void);
#define gpio_status() gpio_info()
#endif
......@@ -34,6 +34,7 @@ COBJS-$(CONFIG_MXS_GPIO) += mxs_gpio.o
COBJS-$(CONFIG_PCA953X) += pca953x.o
COBJS-$(CONFIG_PCA9698) += pca9698.o
COBJS-$(CONFIG_S5P) += s5p_gpio.o
COBJS-$(CONFIG_SANDBOX_GPIO) += sandbox.o
COBJS-$(CONFIG_TEGRA2_GPIO) += tegra2_gpio.o
COBJS-$(CONFIG_DA8XX_GPIO) += da8xx_gpio.o
COBJS-$(CONFIG_ALTERA_PIO) += altera_pio.o
......
/*
* Copyright (c) 2011 The Chromium OS Authors.
* 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
*/
#include <common.h>
#include <asm/gpio.h>
/* Flags for each GPIO */
#define GPIOF_OUTPUT (1 << 0) /* Currently set as an output */
#define GPIOF_HIGH (1 << 1) /* Currently set high */
#define GPIOF_RESERVED (1 << 2) /* Is in use / requested */
struct gpio_state {
const char *label; /* label given by requester */
u8 flags; /* flags (GPIOF_...) */
};
/*
* State of GPIOs
* TODO: Put this into sandbox state
*/
static struct gpio_state state[CONFIG_SANDBOX_GPIO_COUNT];
/* Access routines for GPIO state */
static u8 *get_gpio_flags(unsigned gp)
{
/* assert()'s could be disabled, so make sure we handle that */
assert(gp < ARRAY_SIZE(state));
if (gp >= ARRAY_SIZE(state)) {
static u8 invalid_flags;
printf("sandbox_gpio: error: invalid gpio %u\n", gp);
return &invalid_flags;
}
return &state[gp].flags;
}
static int get_gpio_flag(unsigned gp, int flag)
{
return (*get_gpio_flags(gp) & flag) != 0;
}
static int set_gpio_flag(unsigned gp, int flag, int value)
{
u8 *gpio = get_gpio_flags(gp);
if (value)
*gpio |= flag;
else
*gpio &= ~flag;
return 0;
}
static int check_reserved(unsigned gpio, const char *func)
{
if (!get_gpio_flag(gpio, GPIOF_RESERVED)) {
printf("sandbox_gpio: %s: error: gpio %u not reserved\n",
func, gpio);
return -1;
}
return 0;
}
/*
* Back-channel sandbox-internal-only access to GPIO state
*/
int sandbox_gpio_get_value(unsigned gp)
{
if (get_gpio_flag(gp, GPIOF_OUTPUT))
debug("sandbox_gpio: get_value on output gpio %u\n", gp);
return get_gpio_flag(gp, GPIOF_HIGH);
}
int sandbox_gpio_set_value(unsigned gp, int value)
{
return set_gpio_flag(gp, GPIOF_HIGH, value);
}
int sandbox_gpio_get_direction(unsigned gp)
{
return get_gpio_flag(gp, GPIOF_OUTPUT);
}
int sandbox_gpio_set_direction(unsigned gp, int output)
{
return set_gpio_flag(gp, GPIOF_OUTPUT, output);
}
/*
* These functions implement the public interface within U-Boot
*/
/* set GPIO port 'gp' as an input */
int gpio_direction_input(unsigned gp)
{
debug("%s: gp:%u\n", __func__, gp);
if (check_reserved(gp, __func__))
return -1;
return sandbox_gpio_set_direction(gp, 0);
}
/* set GPIO port 'gp' as an output, with polarity 'value' */
int gpio_direction_output(unsigned gp, int value)
{
debug("%s: gp:%u, value = %d\n", __func__, gp, value);
if (check_reserved(gp, __func__))
return -1;
return sandbox_gpio_set_direction(gp, 1) |
sandbox_gpio_set_value(gp, value);
}
/* read GPIO IN value of port 'gp' */
int gpio_get_value(unsigned gp)
{
debug("%s: gp:%u\n", __func__, gp);
if (check_reserved(gp, __func__))
return -1;
return sandbox_gpio_get_value(gp);
}
/* write GPIO OUT value to port 'gp' */
int gpio_set_value(unsigned gp, int value)
{
debug("%s: gp:%u, value = %d\n", __func__, gp, value);
if (check_reserved(gp, __func__))
return -1;
if (!sandbox_gpio_get_direction(gp)) {
printf("sandbox_gpio: error: set_value on input gpio %u\n", gp);
return -1;
}
return sandbox_gpio_set_value(gp, value);
}
int gpio_request(unsigned gp, const char *label)
{
debug("%s: gp:%u, label:%s\n", __func__, gp, label);
if (gp >= ARRAY_SIZE(state)) {
printf("sandbox_gpio: error: invalid gpio %u\n", gp);
return -1;
}
if (get_gpio_flag(gp, GPIOF_RESERVED)) {
printf("sandbox_gpio: error: gpio %u already reserved\n", gp);
return -1;
}
state[gp].label = label;
return set_gpio_flag(gp, GPIOF_RESERVED, 1);
}
int gpio_free(unsigned gp)
{
debug("%s: gp:%u\n", __func__, gp);
if (check_reserved(gp, __func__))
return -1;
state[gp].label = NULL;
return set_gpio_flag(gp, GPIOF_RESERVED, 0);
}
/* Display GPIO information */
void gpio_info(void)
{
unsigned gpio;
puts("Sandbox GPIOs\n");
for (gpio = 0; gpio < ARRAY_SIZE(state); ++gpio) {
const char *label = state[gpio].label;
printf("%4d: %s: %d [%c] %s\n",
gpio,
sandbox_gpio_get_direction(gpio) ? "out" : " in",
sandbox_gpio_get_value(gpio),
get_gpio_flag(gpio, GPIOF_RESERVED) ? 'x' : ' ',
label ? label : "");
}
}
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