diff options
Diffstat (limited to 'drivers/gpio/pca953x.c')
| -rw-r--r-- | drivers/gpio/pca953x.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c new file mode 100644 index 0000000..390d99a --- /dev/null +++ b/drivers/gpio/pca953x.c @@ -0,0 +1,227 @@ +/* + * 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))))) { + printf("Usage:\n%s\n", cmdtp->usage); + 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 - pca953x gpio access\n", + "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\n" +); + +#endif /* CONFIG_CMD_PCA953X */ |