drivers/gpio/sx151x.c

   1 /*
   2  * (C) Copyright 2013
   3  * Viktar Palstsiuk, Promwad, viktar.palstsiuk@promwad.com
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * Driver for Semtech SX151x SPI GPIO Expanders
  10  */
  11
  12 #include <common.h>
  13 #include <spi.h>
  14 #include <sx151x.h>
  15
  16 #ifndef CONFIG_SX151X_SPI_BUS
  17 #define CONFIG_SX151X_SPI_BUS 0
  18 #endif
  19
  20 /*
  21  * The SX151x registers
  22  */
  23
  24 #ifdef CONFIG_SX151X_GPIO_COUNT_8
  25 /* 8bit: SX1511 */
  26 #define SX151X_REG_DIR          0x07
  27 #define SX151X_REG_DATA         0x08
  28 #else
  29 /* 16bit: SX1512 */
  30 #define SX151X_REG_DIR          0x0F
  31 #define SX151X_REG_DATA         0x11
  32 #endif
  33 #define SX151X_REG_RESET        0x7D
  34
  35 static int sx151x_spi_write(int chip, unsigned char reg, unsigned char val)
  36 {
  37         struct spi_slave *slave;
  38         unsigned char buf[2];
  39         int ret;
  40
  41         slave = spi_setup_slave(CONFIG_SX151X_SPI_BUS, chip, 1000000,
  42                                 SPI_MODE_0);
  43         if (!slave)
  44                 return 0;
  45
  46         spi_claim_bus(slave);
  47
  48         buf[0] = reg;
  49         buf[1] = val;
  50
  51         ret = spi_xfer(slave, 16, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
  52         if (ret < 0)
  53                 printf("spi%d.%d write fail: can't write %02x to %02x: %d\n",
  54                         CONFIG_SX151X_SPI_BUS, chip, val, reg, ret);
  55         else
  56                 printf("spi%d.%d write 0x%02x to register 0x%02x\n",
  57                        CONFIG_SX151X_SPI_BUS, chip, val, reg);
  58         spi_release_bus(slave);
  59         spi_free_slave(slave);
  60
  61         return ret;
  62 }
  63
  64 static int sx151x_spi_read(int chip, unsigned char reg)
  65 {
  66         struct spi_slave *slave;
  67         int ret;
  68
  69         slave = spi_setup_slave(CONFIG_SX151X_SPI_BUS, chip, 1000000,
  70                                 SPI_MODE_0);
  71         if (!slave)
  72                 return 0;
  73
  74         spi_claim_bus(slave);
  75
  76         ret = spi_w8r8(slave, reg | 0x80);
  77         if (ret < 0)
  78                 printf("spi%d.%d read fail: can't read %02x: %d\n",
  79                         CONFIG_SX151X_SPI_BUS, chip, reg, ret);
  80         else
  81                 printf("spi%d.%d read register 0x%02x: 0x%02x\n",
  82                        CONFIG_SX151X_SPI_BUS, chip, reg, ret);
  83
  84         spi_release_bus(slave);
  85         spi_free_slave(slave);
  86
  87         return ret;
  88 }
  89
  90 static inline void sx151x_find_cfg(int gpio, unsigned char *reg, unsigned char *mask)
  91 {
  92         *reg   -= gpio / 8;
  93         *mask   = 1 << (gpio % 8);
  94 }
  95
  96 static int sx151x_write_cfg(int chip, unsigned char gpio, unsigned char reg, int val)
  97 {
  98         unsigned char  mask;
  99         unsigned char  data;
 100         int ret;
 101
 102         sx151x_find_cfg(gpio, &reg, &mask);
 103         ret = sx151x_spi_read(chip, reg);
 104         if (ret < 0)
 105                 return ret;
 106         else
 107                 data = ret;
 108         data &= ~mask;
 109         data |= (val << (gpio % 8)) & mask;
 110         return sx151x_spi_write(chip, reg, data);
 111 }
 112
 113 int sx151x_get_value(int chip, int gpio)
 114 {
 115         unsigned char  reg = SX151X_REG_DATA;
 116         unsigned char  mask;
 117         int ret;
 118
 119         sx151x_find_cfg(gpio, &reg, &mask);
 120         ret = sx151x_spi_read(chip, reg);
 121         if (ret >= 0)
 122                 ret = (ret & mask) != 0 ? 1 : 0;
 123
 124         return ret;
 125 }
 126
 127 int sx151x_set_value(int chip, int gpio, int val)
 128 {
 129         return sx151x_write_cfg(chip, gpio, SX151X_REG_DATA, (val ? 1 : 0));
 130 }
 131
 132 int sx151x_direction_input(int chip, int gpio)
 133 {
 134         return sx151x_write_cfg(chip, gpio, SX151X_REG_DIR, 1);
 135 }
 136
 137 int sx151x_direction_output(int chip, int gpio)
 138 {
 139         return sx151x_write_cfg(chip, gpio, SX151X_REG_DIR, 0);
 140 }
 141
 142 int sx151x_reset(int chip)
 143 {
 144         int err;
 145
 146         err = sx151x_spi_write(chip, SX151X_REG_RESET, 0x12);
 147         if (err < 0)
 148                 return err;
 149
 150         err = sx151x_spi_write(chip, SX151X_REG_RESET, 0x34);
 151         return err;
 152 }
 153
 154 #ifdef CONFIG_CMD_SX151X
 155
 156 int do_sx151x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 157 {
 158         int ret = CMD_RET_USAGE, chip = 0, gpio = 0, val = 0;
 159
 160         if (argc < 3)
 161                 return CMD_RET_USAGE;
 162
 163         /* arg2 used as chip number */
 164         chip = simple_strtoul(argv[2], NULL, 10);
 165
 166         if (strcmp(argv[1], "reset") == 0) {
 167                 ret = sx151x_reset(chip);
 168                 if (!ret) {
 169                         printf("Device at spi%d.%d was reset\n",
 170                                CONFIG_SX151X_SPI_BUS, chip);
 171                 }
 172                 return ret;
 173         }
 174
 175         if (argc < 4)
 176                 return CMD_RET_USAGE;
 177
 178         /* arg3 used as gpio number */
 179         gpio = simple_strtoul(argv[3], NULL, 10);
 180
 181         if (strcmp(argv[1], "get") == 0) {
 182                 ret = sx151x_get_value(chip, gpio);
 183                 if (ret < 0)
 184                         printf("Failed to get value at spi%d.%d gpio %d\n",
 185                                CONFIG_SX151X_SPI_BUS, chip, gpio);
 186                 else {
 187                         printf("Value at spi%d.%d gpio %d is %d\n",
 188                                CONFIG_SX151X_SPI_BUS, chip, gpio, ret);
 189                         ret = 0;
 190                 }
 191                 return ret;
 192         }
 193
 194         if (argc < 5)
 195                 return CMD_RET_USAGE;
 196
 197         /* arg4 used as value or direction */
 198         val = simple_strtoul(argv[4], NULL, 10);
 199
 200         if (strcmp(argv[1], "set") == 0) {
 201                 ret = sx151x_set_value(chip, gpio, val);
 202                 if (ret < 0)
 203                         printf("Failed to set value at spi%d.%d gpio %d\n",
 204                                CONFIG_SX151X_SPI_BUS, chip, gpio);
 205                 else
 206                         printf("New value at spi%d.%d gpio %d is %d\n",
 207                                CONFIG_SX151X_SPI_BUS, chip, gpio, val);
 208                 return ret;
 209         } else if (strcmp(argv[1], "dir") == 0) {
 210                 if (val == 0)
 211                         ret = sx151x_direction_output(chip, gpio);
 212                 else
 213                         ret = sx151x_direction_input(chip, gpio);
 214
 215                 if (ret < 0)
 216                         printf("Failed to set direction of spi%d.%d gpio %d\n",
 217                                CONFIG_SX151X_SPI_BUS, chip, gpio);
 218                 else
 219                         printf("New direction of spi%d.%d gpio %d is %d\n",
 220                                CONFIG_SX151X_SPI_BUS, chip, gpio, val);
 221                 return ret;
 222         }
 223
 224         printf("Please see usage\n");
 225
 226         return ret;
 227 }
 228
 229 U_BOOT_CMD(
 230         sx151x, 5,      1,      do_sx151x,
 231         "sx151x gpio access",
 232         "dir chip gpio 0|1\n"
 233         "       - set gpio direction (0 for output, 1 for input)\n"
 234         "sx151x get chip gpio\n"
 235         "       - get gpio value\n"
 236         "sx151x set chip gpio 0|1\n"
 237         "       - set gpio value\n"
 238         "sx151x reset chip\n"
 239         "       - reset chip"
 240 );
 241
 242 #endif /* CONFIG_CMD_SX151X */