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   1 /*
   2  * Copyright © 2012 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_hmc5883.h>
  21 #include <ao_exti.h>
  22
  23 #if HAS_HMC5883
  24
  25 static uint8_t  ao_hmc5883_configured;
  26
  27 static uint8_t  ao_hmc5883_addr;
  28
  29 static void
  30 ao_hmc5883_reg_write(uint8_t addr, uint8_t data)
  31 {
  32         uint8_t d[2];
  33
  34         d[0] = addr;
  35         d[1] = data;
  36         ao_i2c_get(AO_HMC5883_I2C_INDEX);
  37         ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_WRITE);
  38         ao_i2c_send(d, 2, AO_HMC5883_I2C_INDEX, true);
  39         ao_i2c_put(AO_HMC5883_I2C_INDEX);
  40         ao_hmc5883_addr = addr + 1;
  41 }
  42
  43 static void
  44 ao_hmc5883_read(uint8_t addr, uint8_t *data, uint8_t len)
  45 {
  46         ao_i2c_get(AO_HMC5883_I2C_INDEX);
  47         if (addr != ao_hmc5883_addr) {
  48                 ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_WRITE);
  49                 ao_i2c_send(&addr, 1, AO_HMC5883_I2C_INDEX, false);
  50         }
  51         ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_READ);
  52         ao_i2c_recv(data, len, AO_HMC5883_I2C_INDEX, true);
  53         ao_i2c_put(AO_HMC5883_I2C_INDEX);
  54         ao_hmc5883_addr = 0xff;
  55 }
  56
  57 static uint8_t ao_hmc5883_done;
  58
  59 static void
  60 ao_hmc5883_isr(void)
  61 {
  62         ao_exti_disable(AO_HMC5883_INT_PORT, AO_HMC5883_INT_PIN);
  63         ao_hmc5883_done = 1;
  64         ao_wakeup(&ao_hmc5883_done);
  65 }
  66
  67 static uint32_t ao_hmc5883_missed_irq;
  68
  69 static void
  70 ao_hmc5883_sample(struct ao_hmc5883_sample *sample)
  71 {
  72         uint16_t        *d = (uint16_t *) sample;
  73         int             i = sizeof (*sample) / 2;
  74
  75         ao_hmc5883_done = 0;
  76         ao_exti_enable(AO_HMC5883_INT_PORT, AO_HMC5883_INT_PIN);
  77         ao_hmc5883_reg_write(HMC5883_MODE, HMC5883_MODE_SINGLE);
  78
  79         ao_arch_block_interrupts();
  80         while (!ao_hmc5883_done)
  81                 if (ao_sleep_for(&ao_hmc5883_done, AO_MS_TO_TICKS(10)))
  82                         ++ao_hmc5883_missed_irq;
  83         ao_arch_release_interrupts();
  84
  85         ao_hmc5883_read(HMC5883_X_MSB, (uint8_t *) sample, sizeof (struct ao_hmc5883_sample));
  86 #if __BYTE_ORDER == __LITTLE_ENDIAN
  87         /* byte swap */
  88         while (i--) {
  89                 uint16_t        t = *d;
  90                 *d++ = (uint16_t) ((t >> 8) | (t << 8));
  91         }
  92 #endif
  93 }
  94
  95 static uint8_t
  96 ao_hmc5883_setup(void)
  97 {
  98         uint8_t d;
  99         uint8_t present;
 100
 101         if (ao_hmc5883_configured)
 102                 return 1;
 103
 104         ao_i2c_get(AO_HMC5883_I2C_INDEX);
 105         present = ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_READ);
 106         ao_i2c_recv(&d, 1, AO_HMC5883_I2C_INDEX, true);
 107         ao_i2c_put(AO_HMC5883_I2C_INDEX);
 108
 109         if (!present)
 110                 ao_panic(AO_PANIC_SELF_TEST_HMC5883);
 111
 112         ao_hmc5883_reg_write(HMC5883_CONFIG_A,
 113                              (HMC5883_CONFIG_A_MA_8 << HMC5883_CONFIG_A_MA) |
 114                              (HMC5883_CONFIG_A_DO_15 << HMC5883_CONFIG_A_DO) |
 115                              (HMC5883_CONFIG_A_MS_NORMAL << HMC5883_CONFIG_A_MS));
 116
 117         ao_hmc5883_reg_write(HMC5883_CONFIG_B,
 118                              (HMC5883_CONFIG_B_GN_1_3 << HMC5883_CONFIG_B_GN));
 119
 120         ao_hmc5883_configured = 1;
 121         return 1;
 122 }
 123
 124 struct ao_hmc5883_sample ao_hmc5883_current;
 125
 126 static void
 127 ao_hmc5883(void)
 128 {
 129         struct ao_hmc5883_sample        sample;
 130         ao_hmc5883_setup();
 131         for (;;) {
 132                 ao_hmc5883_sample(&sample);
 133                 ao_arch_block_interrupts();
 134                 ao_hmc5883_current = sample;
 135                 AO_DATA_PRESENT(AO_DATA_HMC5883);
 136                 AO_DATA_WAIT();
 137                 ao_arch_release_interrupts();
 138         }
 139 }
 140
 141 static struct ao_task ao_hmc5883_task;
 142
 143 static void
 144 ao_hmc5883_show(void)
 145 {
 146         printf ("X: %d Z: %d Y: %d missed irq: %lu\n",
 147                 ao_hmc5883_current.x, ao_hmc5883_current.z, ao_hmc5883_current.y, ao_hmc5883_missed_irq);
 148 }
 149
 150 static const struct ao_cmds ao_hmc5883_cmds[] = {
 151         { ao_hmc5883_show,      "M\0Show HMC5883 status" },
 152         { 0, NULL }
 153 };
 154
 155 void
 156 ao_hmc5883_init(void)
 157 {
 158         ao_hmc5883_configured = 0;
 159
 160         ao_enable_port(AO_HMC5883_INT_PORT);
 161         ao_exti_setup(AO_HMC5883_INT_PORT,
 162                       AO_HMC5883_INT_PIN,
 163                       AO_EXTI_MODE_FALLING | AO_EXTI_MODE_PULL_UP,
 164                       ao_hmc5883_isr);
 165
 166         ao_add_task(&ao_hmc5883_task, ao_hmc5883, "hmc5883");
 167         ao_cmd_register(&ao_hmc5883_cmds[0]);
 168 }
 169
 170 #endif