u-boot/drivers/gpio/pca953x.c

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/*
* Copyright 2008 Extreme Engineering Solutions, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* Version 2 as published by the Free Software Foundation.
*
* 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
*/
/*
* Driver for NXP's 4 and 8 bit I2C gpio expanders (eg pca9537, pca9557, etc)
* TODO: support additional devices with more than 8-bits GPIO
*/
#include <common.h>
#include <i2c.h>
#include <pca953x.h>
/* Default to an address that hopefully won't corrupt other i2c devices */
#ifndef CONFIG_SYS_I2C_PCA953X_ADDR
#define CONFIG_SYS_I2C_PCA953X_ADDR (~0)
#endif
enum {
PCA953X_CMD_INFO,
PCA953X_CMD_DEVICE,
PCA953X_CMD_OUTPUT,
PCA953X_CMD_INPUT,
PCA953X_CMD_INVERT,
};
/*
* Modify masked bits in register
*/
static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
{
uint8_t val;
if (i2c_read(chip, addr, 1, &val, 1))
return -1;
val &= ~mask;
val |= data;
return i2c_write(chip, addr, 1, &val, 1);
}
/*
* Set output value of IO pins in 'mask' to corresponding value in 'data'
* 0 = low, 1 = high
*/
int pca953x_set_val(uint8_t chip, uint mask, uint data)
{
return pca953x_reg_write(chip, PCA953X_OUT, mask, data);
}
/*
* Set read polarity of IO pins in 'mask' to corresponding value in 'data'
* 0 = read pin value, 1 = read inverted pin value
*/
int pca953x_set_pol(uint8_t chip, uint mask, uint data)
{
return pca953x_reg_write(chip, PCA953X_POL, mask, data);
}
/*
* Set direction of IO pins in 'mask' to corresponding value in 'data'
* 0 = output, 1 = input
*/
int pca953x_set_dir(uint8_t chip, uint mask, uint data)
{
return pca953x_reg_write(chip, PCA953X_CONF, mask, data);
}
/*
* Read current logic level of all IO pins
*/
int pca953x_get_val(uint8_t chip)
{
uint8_t val;
if (i2c_read(chip, 0, 1, &val, 1))
return -1;
return (int)val;
}
#ifdef CONFIG_CMD_PCA953X
#ifdef CONFIG_CMD_PCA953X_INFO
/*
* Display pca953x information
*/
static int pca953x_info(uint8_t chip)
{
int i;
uint8_t data;
printf("pca953x@ 0x%x:\n\n", chip);
printf("gpio pins: 76543210\n");
printf("-------------------\n");
if (i2c_read(chip, PCA953X_CONF, 1, &data, 1))
return -1;
printf("conf: ");
for (i = 7; i >= 0; i--)
printf("%c", data & (1 << i) ? 'i' : 'o');
printf("\n");
if (i2c_read(chip, PCA953X_POL, 1, &data, 1))
return -1;
printf("invert: ");
for (i = 7; i >= 0; i--)
printf("%c", data & (1 << i) ? '1' : '0');
printf("\n");
if (i2c_read(chip, PCA953X_IN, 1, &data, 1))
return -1;
printf("input: ");
for (i = 7; i >= 0; i--)
printf("%c", data & (1 << i) ? '1' : '0');
printf("\n");
if (i2c_read(chip, PCA953X_OUT, 1, &data, 1))
return -1;
printf("output: ");
for (i = 7; i >= 0; i--)
printf("%c", data & (1 << i) ? '1' : '0');
printf("\n");
return 0;
}
#endif /* CONFIG_CMD_PCA953X_INFO */
cmd_tbl_t cmd_pca953x[] = {
U_BOOT_CMD_MKENT(device, 3, 0, (void *)PCA953X_CMD_DEVICE, "", ""),
U_BOOT_CMD_MKENT(output, 4, 0, (void *)PCA953X_CMD_OUTPUT, "", ""),
U_BOOT_CMD_MKENT(input, 3, 0, (void *)PCA953X_CMD_INPUT, "", ""),
U_BOOT_CMD_MKENT(invert, 4, 0, (void *)PCA953X_CMD_INVERT, "", ""),
#ifdef CONFIG_CMD_PCA953X_INFO
U_BOOT_CMD_MKENT(info, 2, 0, (void *)PCA953X_CMD_INFO, "", ""),
#endif
};
int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
int val;
ulong ul_arg2 = 0;
ulong ul_arg3 = 0;
cmd_tbl_t *c;
c = find_cmd_tbl(argv[1], cmd_pca953x, ARRAY_SIZE(cmd_pca953x));
/* All commands but "device" require 'maxargs' arguments */
if (!c || !((argc == (c->maxargs)) ||
(((int)c->cmd == PCA953X_CMD_DEVICE) &&
(argc == (c->maxargs - 1))))) {
cmd_usage(cmdtp);
return 1;
}
/* arg2 used as chip number or pin number */
if (argc > 2)
ul_arg2 = simple_strtoul(argv[2], NULL, 16);
/* arg3 used as pin or invert value */
if (argc > 3)
ul_arg3 = simple_strtoul(argv[3], NULL, 16) & 0x1;
switch ((int)c->cmd) {
#ifdef CONFIG_CMD_PCA953X_INFO
case PCA953X_CMD_INFO:
return pca953x_info(chip);
#endif
case PCA953X_CMD_DEVICE:
if (argc == 3)
chip = (uint8_t)ul_arg2;
printf("Current device address: 0x%x\n", chip);
return 0;
case PCA953X_CMD_INPUT:
pca953x_set_dir(chip, (1 << ul_arg2),
PCA953X_DIR_IN << ul_arg2);
val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;
printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2, val);
return val;
case PCA953X_CMD_OUTPUT:
pca953x_set_dir(chip, (1 << ul_arg2),
(PCA953X_DIR_OUT << ul_arg2));
return pca953x_set_val(chip, (1 << ul_arg2),
(ul_arg3 << ul_arg2));
case PCA953X_CMD_INVERT:
return pca953x_set_pol(chip, (1 << ul_arg2),
(ul_arg3 << ul_arg2));
default:
/* We should never get here */
return 1;
}
}
U_BOOT_CMD(
pca953x, 5, 1, do_pca953x,
"pca953x gpio access",
"device [dev]\n"
" - show or set current device address\n"
#ifdef CONFIG_CMD_PCA953X_INFO
"pca953x info\n"
" - display info for current chip\n"
#endif
"pca953x output pin 0|1\n"
" - set pin as output and drive low or high\n"
"pca953x invert pin 0|1\n"
" - disable/enable polarity inversion for reads\n"
"pca953x intput pin\n"
" - set pin as input and read value"
);
#endif /* CONFIG_CMD_PCA953X */