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 */
  28 struct 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  */
  46 static 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
  66 error:
  67         i2c_set_bus_num(org_bus_num);
  68         return ret;
  69 }
  70
  71 static 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
  86 error:
  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  */
  95 int 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  */
 107 int 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  */
 119 int 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  */
 130 int 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  */
 144 int 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  */
 170 static 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
 215 cmd_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
 223 int 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         }
 311 error:
 312         if (ret == CMD_RET_FAILURE)
 313                 eprintf("Error talking to chip at 0x%x\n", chip);
 314
 315         return ret;
 316 }
 317
 318 U_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 */