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   1 /*
   2  * Copyright © 2021 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  17  */
  18
  19 #include <ao.h>
  20 #include <ao_mmc5983.h>
  21 #include <ao_exti.h>
  22
  23 #if HAS_MMC5983
  24
  25 struct ao_mmc5983_sample        ao_mmc5983_current;
  26
  27 static uint8_t  ao_mmc5983_configured;
  28
  29 #ifdef MMC5983_I2C
  30 #include <ao_i2c_bit.h>
  31
  32 static void
  33 ao_mmc5983_reg_write(uint8_t addr, uint8_t data)
  34 {
  35         uint8_t d[2];
  36
  37         d[0] = addr;
  38         d[1] = data;
  39
  40         ao_i2c_bit_start(MMC5983_I2C_ADDR);
  41         ao_i2c_bit_send(d, 2);
  42         ao_i2c_bit_stop();
  43 }
  44
  45 static uint8_t
  46 ao_mmc5983_reg_read(uint8_t addr)
  47 {
  48         uint8_t d[1];
  49
  50         ao_i2c_bit_start(MMC5983_I2C_ADDR);
  51         d[0] = addr;
  52         ao_i2c_bit_send(d, 1);
  53         ao_i2c_bit_restart(MMC5983_I2C_ADDR | 1);
  54         ao_i2c_bit_recv(d, 1);
  55         ao_i2c_bit_stop();
  56         return d[0];
  57 }
  58
  59 static void
  60 ao_mmc5983_sample(struct ao_mmc5983_sample *sample)
  61 {
  62         struct ao_mmc5983_raw   raw;
  63
  64         ao_i2c_bit_start(MMC5983_I2C_ADDR);
  65         raw.addr = MMC5983_X_OUT_0;
  66         ao_i2c_bit_send(&raw.addr, 1);
  67         ao_i2c_bit_restart(MMC5983_I2C_ADDR | 1);
  68         ao_i2c_bit_recv(&raw.x0, 7);
  69         ao_i2c_bit_stop();
  70
  71         sample->x = raw.x0 << 10 | raw.x1 << 2 | ((raw.xyz2 >> 6) & 3);
  72         sample->y = raw.y0 << 10 | raw.y1 << 2 | ((raw.xyz2 >> 4) & 3);
  73         sample->z = raw.z0 << 10 | raw.z1 << 2 | ((raw.xyz2 >> 2) & 3);
  74 }
  75
  76 #else
  77 #define AO_MMC5983_SPI_SPEED    ao_spi_speed(2000000)
  78
  79 static void
  80 ao_mmc5983_start(void) {
  81         ao_spi_get_bit(AO_MMC5983_SPI_CS_PORT,
  82                        AO_MMC5983_SPI_CS_PIN,
  83                        AO_MMC5983_SPI_INDEX,
  84                        AO_MMC5983_SPI_SPEED);
  85 }
  86
  87 static void
  88 ao_mmc5983_stop(void) {
  89         ao_spi_put_bit(AO_MMC5983_SPI_CS_PORT,
  90                        AO_MMC5983_SPI_CS_PIN,
  91                        AO_MMC5983_SPI_INDEX);
  92 }
  93
  94
  95 static void
  96 ao_mmc5983_reg_write(uint8_t addr, uint8_t data)
  97 {
  98         uint8_t d[2];
  99
 100         d[0] = addr;
 101         d[1] = data;
 102         ao_mmc5983_start();
 103         ao_spi_send(d, 2, AO_MMC5983_SPI_INDEX);
 104         ao_mmc5983_stop();
 105 }
 106
 107 static uint8_t
 108 ao_mmc5983_reg_read(uint8_t addr)
 109 {
 110         uint8_t d[2];
 111
 112         d[0] = addr | MMC5983_READ;
 113         ao_mmc5983_start();
 114         ao_spi_duplex(d, d, 2, AO_MMC5983_SPI_INDEX);
 115         ao_mmc5983_stop();
 116
 117         return d[1];
 118 }
 119
 120 static void
 121 ao_mmc5983_duplex(uint8_t *dst, uint8_t len)
 122 {
 123         ao_mmc5983_start();
 124         ao_spi_duplex(dst, dst, len, AO_MMC5983_SPI_INDEX);
 125         ao_mmc5983_stop();
 126 }
 127
 128 static void
 129 ao_mmc5983_sample(struct ao_mmc5983_sample *sample)
 130 {
 131         struct ao_mmc5983_raw   raw;
 132
 133         raw.addr = MMC5983_X_OUT_0 | MMC5983_READ;
 134         ao_mmc5983_duplex((uint8_t *) &raw, sizeof (raw));
 135
 136         sample->x = raw.x0 << 10 | raw.x1 << 2 | ((raw.xyz2 >> 6) & 3);
 137         sample->y = raw.y0 << 10 | raw.y1 << 2 | ((raw.xyz2 >> 4) & 3);
 138         sample->z = raw.z0 << 10 | raw.z1 << 2 | ((raw.xyz2 >> 2) & 3);
 139 }
 140 #endif
 141
 142 static uint8_t product_id;
 143
 144 static uint8_t
 145 ao_mmc5983_setup(void)
 146 {
 147
 148         if (ao_mmc5983_configured)
 149                 return 1;
 150
 151         /* Delay for power up time (10ms) */
 152         ao_delay(AO_MS_TO_TICKS(10));
 153
 154         ao_mmc5983_reg_write(MMC5983_CONTROL_1,
 155                              1 << MMC5983_CONTROL_1_SW_RST);
 156
 157         /* Delay for power up time (10ms) */
 158         ao_delay(AO_MS_TO_TICKS(10));
 159
 160         /* Check product ID */
 161         product_id = ao_mmc5983_reg_read(MMC5983_PRODUCT_ID);
 162         if (product_id != MMC5983_PRODUCT_ID_PRODUCT_I2C &&
 163             product_id != MMC5983_PRODUCT_ID_PRODUCT_SPI)
 164         {
 165                 AO_SENSOR_ERROR(AO_DATA_MMC5983);
 166         }
 167
 168         /* Set bandwidth to 200Hz */
 169         ao_mmc5983_reg_write(MMC5983_CONTROL_1,
 170                              MMC5983_CONTROL_1_BW_200 << MMC5983_CONTROL_1_BW);
 171
 172         /* Measure at 200Hz so we get recent samples by just reading
 173          * the registers
 174          */
 175         ao_mmc5983_reg_write(MMC5983_CONTROL_2,
 176                              (1 << MMC5983_CONTROL_2_CMM_EN) |
 177                              (MMC5983_CONTROL_2_CM_FREQ_200HZ << MMC5983_CONTROL_2_CM_FREQ));
 178
 179         ao_mmc5983_configured = 1;
 180         return 1;
 181 }
 182
 183 struct ao_mmc5983_sample ao_mmc5983_current;
 184
 185 static void
 186 ao_mmc5983(void)
 187 {
 188         struct ao_mmc5983_sample        sample;
 189         ao_mmc5983_setup();
 190         for (;;) {
 191                 ao_mmc5983_sample(&sample);
 192                 ao_arch_block_interrupts();
 193                 ao_mmc5983_current = sample;
 194                 AO_DATA_PRESENT(AO_DATA_MMC5983);
 195                 AO_DATA_WAIT();
 196                 ao_arch_release_interrupts();
 197         }
 198 }
 199
 200 static struct ao_task ao_mmc5983_task;
 201
 202 static void
 203 ao_mmc5983_show(void)
 204 {
 205         printf ("MMC5983: %d %d %d\n",
 206                 ao_mmc5983_along(&ao_mmc5983_current),
 207                 ao_mmc5983_across(&ao_mmc5983_current),
 208                 ao_mmc5983_through(&ao_mmc5983_current));
 209 }
 210
 211 static const struct ao_cmds ao_mmc5983_cmds[] = {
 212         { ao_mmc5983_show,      "M\0Show MMC5983 status" },
 213         { 0, NULL }
 214 };
 215
 216 void
 217 ao_mmc5983_init(void)
 218 {
 219         ao_mmc5983_configured = 0;
 220
 221 #ifdef MMC5983_I2C
 222         ao_enable_output(AO_MMC5983_SPI_CS_PORT, AO_MMC5983_SPI_CS_PIN, 1);
 223 #else
 224         ao_enable_input(AO_MMC5983_SPI_MISO_PORT,
 225                         AO_MMC5983_SPI_MISO_PIN,
 226                         AO_EXTI_MODE_PULL_NONE);
 227
 228         ao_enable_output(AO_MMC5983_SPI_CLK_PORT,
 229                          AO_MMC5983_SPI_CLK_PIN,
 230                          1);
 231
 232         ao_enable_output(AO_MMC5983_SPI_MOSI_PORT,
 233                          AO_MMC5983_SPI_MOSI_PIN,
 234                          0);
 235
 236         ao_spi_init_cs(AO_MMC5983_SPI_CS_PORT, (1 << AO_MMC5983_SPI_CS_PIN));
 237 #endif
 238
 239         ao_add_task(&ao_mmc5983_task, ao_mmc5983, "mmc5983");
 240         ao_cmd_register(&ao_mmc5983_cmds[0]);
 241 }
 242
 243 #endif