LXR uboot/drivers/gpio/tca642x.c

   1/*
   2 * Copyright 2013 Texas Instruments, Inc.
   3 * Author: Dan Murphy <dmurphy@ti.com>
   4 *
   5 * Derived work from the pca953x.c driver
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License as
   9 * published by the Free Software Foundation; either version 2 of
  10 * the License, or (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20 * MA 02111-1307 USA
  21 */
  22
  23#include <common.h>
  24#include <i2c.h>
  25#include <tca642x.h>
  26
  27/* tca642x register address definitions */
  28struct tca642x_bank_info tca642x_regs[] = {
  29        { .input_reg = 0x00,
  30          .output_reg = 0x04,
  31          .polarity_reg = 0x08,
  32          .configuration_reg = 0x0c },
  33        { .input_reg = 0x01,
  34          .output_reg = 0x05,
  35          .polarity_reg = 0x09,
  36          .configuration_reg = 0x0d },
  37        { .input_reg = 0x02,
  38          .output_reg = 0x06,
  39          .polarity_reg = 0x0a,
  40          .configuration_reg = 0x0e },
  41};
  42
  43/*
  44 * Modify masked bits in register
  45 */
  46static int tca642x_reg_write(uchar chip, uint8_t addr,
  47                uint8_t reg_bit, uint8_t data)
  48{
  49        uint8_t valw;
  50        int org_bus_num;
  51        int ret;
  52
  53        org_bus_num = i2c_get_bus_num();
  54        i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
  55
  56        if (i2c_read(chip, addr, 1, (uint8_t *)&valw, 1)) {
  57                printf("Could not read before writing\n");
  58                ret = -1;
  59                goto error;
  60        }
  61        valw &= ~reg_bit;
  62        valw |= data;
  63
  64        ret = i2c_write(chip, addr, 1, (u8 *)&valw, 1);
  65
  66error:
  67        i2c_set_bus_num(org_bus_num);
  68        return ret;
  69}
  70
  71static int tca642x_reg_read(uchar chip, uint8_t addr, uint8_t *data)
  72{
  73        uint8_t valw;
  74        int org_bus_num;
  75        int ret = 0;
  76
  77        org_bus_num = i2c_get_bus_num();
  78        i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
  79        if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
  80                ret = -1;
  81                goto error;
  82        }
  83
  84        *data = valw;
  85
  86error:
  87        i2c_set_bus_num(org_bus_num);
  88        return ret;
  89}
  90
  91/*
  92 * Set output value of IO pins in 'reg_bit' to corresponding value in 'data'
  93 * 0 = low, 1 = high
  94 */
  95int tca642x_set_val(uchar chip, uint8_t gpio_bank,
  96                                        uint8_t reg_bit, uint8_t data)
  97{
  98        uint8_t out_reg = tca642x_regs[gpio_bank].output_reg;
  99
 100        return tca642x_reg_write(chip, out_reg, reg_bit, data);
 101}
 102
 103/*
 104 * Set read polarity of IO pins in 'reg_bit' to corresponding value in 'data'
 105 * 0 = read pin value, 1 = read inverted pin value
 106 */
 107int tca642x_set_pol(uchar chip, uint8_t gpio_bank,
 108                                        uint8_t reg_bit, uint8_t data)
 109{
 110        uint8_t pol_reg = tca642x_regs[gpio_bank].polarity_reg;
 111
 112        return tca642x_reg_write(chip, pol_reg, reg_bit, data);
 113}
 114
 115/*
 116 * Set direction of IO pins in 'reg_bit' to corresponding value in 'data'
 117 * 0 = output, 1 = input
 118 */
 119int tca642x_set_dir(uchar chip, uint8_t gpio_bank,
 120                                        uint8_t reg_bit, uint8_t data)
 121{
 122        uint8_t config_reg = tca642x_regs[gpio_bank].configuration_reg;
 123
 124        return tca642x_reg_write(chip, config_reg, reg_bit, data);
 125}
 126
 127/*
 128 * Read current logic level of all IO pins
 129 */
 130int tca642x_get_val(uchar chip, uint8_t gpio_bank)
 131{
 132        uint8_t val;
 133        uint8_t in_reg = tca642x_regs[gpio_bank].input_reg;
 134
 135        if (tca642x_reg_read(chip, in_reg, &val) < 0)
 136                return -1;
 137
 138        return (int)val;
 139}
 140
 141/*
 142 * Set the inital register states for the tca642x gpio expander
 143 */
 144int tca642x_set_inital_state(uchar chip, struct tca642x_bank_info init_data[])
 145{
 146        int i, ret;
 147        uint8_t config_reg;
 148        uint8_t polarity_reg;
 149        uint8_t output_reg;
 150
 151        for (i = 0; i < 3; i++) {
 152                config_reg = tca642x_regs[i].configuration_reg;
 153                ret = tca642x_reg_write(chip, config_reg, 0xff,
 154                                init_data[i].configuration_reg);
 155                polarity_reg = tca642x_regs[i].polarity_reg;
 156                ret = tca642x_reg_write(chip, polarity_reg, 0xff,
 157                                init_data[i].polarity_reg);
 158                output_reg = tca642x_regs[i].output_reg;
 159                ret = tca642x_reg_write(chip, output_reg, 0xff,
 160                                init_data[i].output_reg);
 161        }
 162
 163        return ret;
 164}
 165
 166#ifdef CONFIG_CMD_TCA642X
 167/*
 168 * Display tca642x information
 169 */
 170static int tca642x_info(uchar chip)
 171{
 172        int i, j;
 173        uint8_t data;
 174
 175        printf("tca642x@ 0x%x (%d pins):\n", chip, 24);
 176        for (i = 0; i < 3; i++) {
 177                printf("Bank %i\n", i);
 178                if (tca642x_reg_read(chip,
 179                                     tca642x_regs[i].configuration_reg,
 180                                     &data) < 0)
 181                        return -1;
 182                printf("\tConfiguration: ");
 183                for (j = 7; j >= 0; j--)
 184                        printf("%c", data & (1 << j) ? 'i' : 'o');
 185                printf("\n");
 186
 187                if (tca642x_reg_read(chip,
 188                                     tca642x_regs[i].polarity_reg, &data) < 0)
 189                        return -1;
 190                printf("\tPolarity: ");
 191                for (j = 7; j >= 0; j--)
 192                        printf("%c", data & (1 << j) ? '1' : '0');
 193                printf("\n");
 194
 195                if (tca642x_reg_read(chip,
 196                                     tca642x_regs[i].input_reg, &data) < 0)
 197                        return -1;
 198                printf("\tInput value: ");
 199                for (j = 7; j >= 0; j--)
 200                        printf("%c", data & (1 << j) ? '1' : '0');
 201                printf("\n");
 202
 203                if (tca642x_reg_read(chip,
 204                                     tca642x_regs[i].output_reg, &data) < 0)
 205                        return -1;
 206                printf("\tOutput value: ");
 207                for (j = 7; j >= 0; j--)
 208                        printf("%c", data & (1 << j) ? '1' : '0');
 209                printf("\n");
 210        }
 211
 212        return 0;
 213}
 214
 215cmd_tbl_t cmd_tca642x[] = {
 216        U_BOOT_CMD_MKENT(device, 3, 0, (void *)TCA642X_CMD_DEVICE, "", ""),
 217        U_BOOT_CMD_MKENT(output, 4, 0, (void *)TCA642X_CMD_OUTPUT, "", ""),
 218        U_BOOT_CMD_MKENT(input, 3, 0, (void *)TCA642X_CMD_INPUT, "", ""),
 219        U_BOOT_CMD_MKENT(invert, 4, 0, (void *)TCA642X_CMD_INVERT, "", ""),
 220        U_BOOT_CMD_MKENT(info, 2, 0, (void *)TCA642X_CMD_INFO, "", ""),
 221};
 222
 223int do_tca642x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 224{
 225        static uchar chip = CONFIG_SYS_I2C_TCA642X_ADDR;
 226        int ret = CMD_RET_USAGE, val;
 227        uint8_t gpio_bank = 0;
 228        uint8_t bank_shift;
 229        ulong ul_arg2 = 0;
 230        ulong ul_arg3 = 0;
 231        cmd_tbl_t *c;
 232
 233        c = find_cmd_tbl(argv[1], cmd_tca642x, ARRAY_SIZE(cmd_tca642x));
 234
 235        /* All commands but "device" require 'maxargs' arguments */
 236        if (!c ||
 237            !((argc == (c->maxargs)) ||
 238            (((int)c->cmd == TCA642X_CMD_DEVICE) &&
 239            (argc == (c->maxargs - 1))))) {
 240                return CMD_RET_USAGE;
 241        }
 242
 243        /* arg2 used as chip number or pin number */
 244        if (argc > 2)
 245                ul_arg2 = simple_strtoul(argv[2], NULL, 10);
 246
 247        /* arg3 used as pin or invert value */
 248        if (argc > 3) {
 249                ul_arg3 = simple_strtoul(argv[3], NULL, 10) & 0x1;
 250                if (ul_arg2 <= 7) {
 251                        gpio_bank = 0;
 252                } else if ((ul_arg2 >= 10) && (ul_arg2 <= 17)) {
 253                        gpio_bank = 1;
 254                } else if ((ul_arg2 >= 20) && (ul_arg2 <= 27)) {
 255                        gpio_bank = 2;
 256                } else {
 257                        printf("Requested pin is not available\n");
 258                        ret = CMD_RET_FAILURE;
 259                        goto error;
 260                }
 261        }
 262
 263        switch ((int)c->cmd) {
 264        case TCA642X_CMD_INFO:
 265                ret = tca642x_info(chip);
 266                if (ret)
 267                        ret = CMD_RET_FAILURE;
 268                break;
 269
 270        case TCA642X_CMD_DEVICE:
 271                if (argc == 3)
 272                        chip = (uint8_t)ul_arg2;
 273                printf("Current device address: 0x%x\n", chip);
 274                ret = CMD_RET_SUCCESS;
 275                break;
 276
 277        case TCA642X_CMD_INPUT:
 278                bank_shift = ul_arg2 - (gpio_bank * 10);
 279                ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
 280                                TCA642X_DIR_IN << bank_shift);
 281                val = (tca642x_get_val(chip, gpio_bank) &
 282                                (1 << bank_shift)) != 0;
 283
 284                if (ret)
 285                        ret = CMD_RET_FAILURE;
 286                else
 287                        printf("chip 0x%02x, pin 0x%lx = %d\n", chip,
 288                               ul_arg2, val);
 289                break;
 290
 291        case TCA642X_CMD_OUTPUT:
 292                bank_shift = ul_arg2 - (gpio_bank * 10);
 293                ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
 294                                (TCA642X_DIR_OUT << bank_shift));
 295                if (!ret)
 296                        ret = tca642x_set_val(chip,
 297                                              gpio_bank, (1 << bank_shift),
 298                                              (ul_arg3 << bank_shift));
 299                if (ret)
 300                        ret = CMD_RET_FAILURE;
 301                break;
 302
 303        case TCA642X_CMD_INVERT:
 304                bank_shift = ul_arg2 - (gpio_bank * 10);
 305                ret = tca642x_set_pol(chip, gpio_bank, (1 << bank_shift),
 306                                        (ul_arg3 << bank_shift));
 307                if (ret)
 308                        ret = CMD_RET_FAILURE;
 309                break;
 310        }
 311error:
 312        if (ret == CMD_RET_FAILURE)
 313                eprintf("Error talking to chip at 0x%x\n", chip);
 314
 315        return ret;
 316}
 317
 318U_BOOT_CMD(
 319        tca642x,        5,      1,      do_tca642x,
 320        "tca642x gpio access",
 321        "device [dev]\n"
 322        "       - show or set current device address\n"
 323        "tca642x info\n"
 324        "       - display info for current chip\n"
 325        "tca642x output pin 0|1\n"
 326        "       - set pin as output and drive low or high\n"
 327        "tca642x invert pin 0|1\n"
 328        "       - disable/enable polarity inversion for reads\n"
 329        "tca642x input pin\n"
 330        "       - set pin as input and read value"
 331);
 332
 333#endif /* CONFIG_CMD_TCA642X */
 334