drivers/gpio/pca953x.c

   1 /*
   2  * Copyright 2008 Extreme Engineering Solutions, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * Version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  16  * MA 02111-1307 USA
  17  */
  18
  19 /*
  20  * Driver for NXP's 4 and 8 bit I2C gpio expanders (eg pca9537, pca9557, etc)
  21  * TODO: support additional devices with more than 8-bits GPIO
  22  */
  23
  24 #include <common.h>
  25 #include <i2c.h>
  26 #include <pca953x.h>
  27
  28 /* Default to an address that hopefully won't corrupt other i2c devices */
  29 #ifndef CONFIG_SYS_I2C_PCA953X_ADDR
  30 #define CONFIG_SYS_I2C_PCA953X_ADDR     (~0)
  31 #endif
  32
  33 enum {
  34         PCA953X_CMD_INFO,
  35         PCA953X_CMD_DEVICE,
  36         PCA953X_CMD_OUTPUT,
  37         PCA953X_CMD_INPUT,
  38         PCA953X_CMD_INVERT,
  39 };
  40
  41 /*
  42  * Modify masked bits in register
  43  */
  44 static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
  45 {
  46         uint8_t val;
  47
  48         if (i2c_read(chip, addr, 1, &val, 1))
  49                 return -1;
  50
  51         val &= ~mask;
  52         val |= data;
  53
  54         return i2c_write(chip, addr, 1, &val, 1);
  55 }
  56
  57 /*
  58  * Set output value of IO pins in 'mask' to corresponding value in 'data'
  59  * 0 = low, 1 = high
  60  */
  61 int pca953x_set_val(uint8_t chip, uint mask, uint data)
  62 {
  63         return pca953x_reg_write(chip, PCA953X_OUT, mask, data);
  64 }
  65
  66 /*
  67  * Set read polarity of IO pins in 'mask' to corresponding value in 'data'
  68  * 0 = read pin value, 1 = read inverted pin value
  69  */
  70 int pca953x_set_pol(uint8_t chip, uint mask, uint data)
  71 {
  72         return pca953x_reg_write(chip, PCA953X_POL, mask, data);
  73 }
  74
  75 /*
  76  * Set direction of IO pins in 'mask' to corresponding value in 'data'
  77  * 0 = output, 1 = input
  78  */
  79 int pca953x_set_dir(uint8_t chip, uint mask, uint data)
  80 {
  81         return pca953x_reg_write(chip, PCA953X_CONF, mask, data);
  82 }
  83
  84 /*
  85  * Read current logic level of all IO pins
  86  */
  87 int pca953x_get_val(uint8_t chip)
  88 {
  89         uint8_t val;
  90
  91         if (i2c_read(chip, 0, 1, &val, 1))
  92                 return -1;
  93
  94         return (int)val;
  95 }
  96
  97 #ifdef CONFIG_CMD_PCA953X
  98 #ifdef CONFIG_CMD_PCA953X_INFO
  99 /*
 100  * Display pca953x information
 101  */
 102 static int pca953x_info(uint8_t chip)
 103 {
 104         int i;
 105         uint8_t data;
 106
 107         printf("pca953x@ 0x%x:\n\n", chip);
 108         printf("gpio pins: 76543210\n");
 109         printf("-------------------\n");
 110
 111         if (i2c_read(chip, PCA953X_CONF, 1, &data, 1))
 112                 return -1;
 113         printf("conf:      ");
 114         for (i = 7; i >= 0; i--)
 115                 printf("%c", data & (1 << i) ? 'i' : 'o');
 116         printf("\n");
 117
 118         if (i2c_read(chip, PCA953X_POL, 1, &data, 1))
 119                 return -1;
 120         printf("invert:    ");
 121         for (i = 7; i >= 0; i--)
 122                 printf("%c", data & (1 << i) ? '1' : '0');
 123         printf("\n");
 124
 125         if (i2c_read(chip, PCA953X_IN, 1, &data, 1))
 126                 return -1;
 127         printf("input:     ");
 128         for (i = 7; i >= 0; i--)
 129                 printf("%c", data & (1 << i) ? '1' : '0');
 130         printf("\n");
 131
 132         if (i2c_read(chip, PCA953X_OUT, 1, &data, 1))
 133                 return -1;
 134         printf("output:    ");
 135         for (i = 7; i >= 0; i--)
 136                 printf("%c", data & (1 << i) ? '1' : '0');
 137         printf("\n");
 138
 139         return 0;
 140 }
 141 #endif /* CONFIG_CMD_PCA953X_INFO */
 142
 143 cmd_tbl_t cmd_pca953x[] = {
 144         U_BOOT_CMD_MKENT(device, 3, 0, (void *)PCA953X_CMD_DEVICE, "", ""),
 145         U_BOOT_CMD_MKENT(output, 4, 0, (void *)PCA953X_CMD_OUTPUT, "", ""),
 146         U_BOOT_CMD_MKENT(input, 3, 0, (void *)PCA953X_CMD_INPUT, "", ""),
 147         U_BOOT_CMD_MKENT(invert, 4, 0, (void *)PCA953X_CMD_INVERT, "", ""),
 148 #ifdef CONFIG_CMD_PCA953X_INFO
 149         U_BOOT_CMD_MKENT(info, 2, 0, (void *)PCA953X_CMD_INFO, "", ""),
 150 #endif
 151 };
 152
 153 int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 154 {
 155         static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
 156         int val;
 157         ulong ul_arg2 = 0;
 158         ulong ul_arg3 = 0;
 159         cmd_tbl_t *c;
 160
 161         c = find_cmd_tbl(argv[1], cmd_pca953x, ARRAY_SIZE(cmd_pca953x));
 162
 163         /* All commands but "device" require 'maxargs' arguments */
 164         if (!c || !((argc == (c->maxargs)) ||
 165                 (((int)c->cmd == PCA953X_CMD_DEVICE) &&
 166                  (argc == (c->maxargs - 1))))) {
 167                 cmd_usage(cmdtp);
 168                 return 1;
 169         }
 170
 171         /* arg2 used as chip number or pin number */
 172         if (argc > 2)
 173                 ul_arg2 = simple_strtoul(argv[2], NULL, 16);
 174
 175         /* arg3 used as pin or invert value */
 176         if (argc > 3)
 177                 ul_arg3 = simple_strtoul(argv[3], NULL, 16) & 0x1;
 178
 179         switch ((int)c->cmd) {
 180 #ifdef CONFIG_CMD_PCA953X_INFO
 181         case PCA953X_CMD_INFO:
 182                 return pca953x_info(chip);
 183 #endif
 184         case PCA953X_CMD_DEVICE:
 185                 if (argc == 3)
 186                         chip = (uint8_t)ul_arg2;
 187                 printf("Current device address: 0x%x\n", chip);
 188                 return 0;
 189         case PCA953X_CMD_INPUT:
 190                 pca953x_set_dir(chip, (1 << ul_arg2),
 191                                 PCA953X_DIR_IN << ul_arg2);
 192                 val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;
 193
 194                 printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2, val);
 195                 return val;
 196         case PCA953X_CMD_OUTPUT:
 197                 pca953x_set_dir(chip, (1 << ul_arg2),
 198                                 (PCA953X_DIR_OUT << ul_arg2));
 199                 return pca953x_set_val(chip, (1 << ul_arg2),
 200                                         (ul_arg3 << ul_arg2));
 201         case PCA953X_CMD_INVERT:
 202                 return pca953x_set_pol(chip, (1 << ul_arg2),
 203                                         (ul_arg3 << ul_arg2));
 204         default:
 205                 /* We should never get here */
 206                 return 1;
 207         }
 208 }
 209
 210 U_BOOT_CMD(
 211         pca953x,        5,      1,      do_pca953x,
 212         "pca953x        - pca953x gpio access\n",
 213         "device [dev]\n"
 214         "       - show or set current device address\n"
 215 #ifdef CONFIG_CMD_PCA953X_INFO
 216         "pca953x info\n"
 217         "       - display info for current chip\n"
 218 #endif
 219         "pca953x output pin 0|1\n"
 220         "       - set pin as output and drive low or high\n"
 221         "pca953x invert pin 0|1\n"
 222         "       - disable/enable polarity inversion for reads\n"
 223         "pca953x intput pin\n"
 224         "       - set pin as input and read value\n"
 225 );
 226
 227 #endif /* CONFIG_CMD_PCA953X */