diff options
Diffstat (limited to 'src/drivers/ao_hmc5883.c')
| -rw-r--r-- | src/drivers/ao_hmc5883.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/src/drivers/ao_hmc5883.c b/src/drivers/ao_hmc5883.c new file mode 100644 index 00000000..ade6c263 --- /dev/null +++ b/src/drivers/ao_hmc5883.c @@ -0,0 +1,170 @@ +/* + * Copyright © 2012 Keith Packard <keithp@keithp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#include <ao.h> +#include <ao_hmc5883.h> +#include <ao_exti.h> + +#if HAS_HMC5883 + +static uint8_t ao_hmc5883_configured; + +static uint8_t ao_hmc5883_addr; + +static void +ao_hmc5883_reg_write(uint8_t addr, uint8_t data) +{ + uint8_t d[2]; + + d[0] = addr; + d[1] = data; + ao_i2c_get(AO_HMC5883_I2C_INDEX); + ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_WRITE); + ao_i2c_send(d, 2, AO_HMC5883_I2C_INDEX, TRUE); + ao_i2c_put(AO_HMC5883_I2C_INDEX); + ao_hmc5883_addr = addr + 1; +} + +static void +ao_hmc5883_read(uint8_t addr, uint8_t *data, uint8_t len) +{ + ao_i2c_get(AO_HMC5883_I2C_INDEX); + if (addr != ao_hmc5883_addr) { + ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_WRITE); + ao_i2c_send(&addr, 1, AO_HMC5883_I2C_INDEX, FALSE); + } + ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_READ); + ao_i2c_recv(data, len, AO_HMC5883_I2C_INDEX, TRUE); + ao_i2c_put(AO_HMC5883_I2C_INDEX); + ao_hmc5883_addr = 0xff; +} + +static uint8_t ao_hmc5883_done; + +static void +ao_hmc5883_isr(void) +{ + ao_exti_disable(AO_HMC5883_INT_PORT, AO_HMC5883_INT_PIN); + ao_hmc5883_done = 1; + ao_wakeup(&ao_hmc5883_done); +} + +static uint32_t ao_hmc5883_missed_irq; + +void +ao_hmc5883_sample(struct ao_hmc5883_sample *sample) +{ + uint16_t *d = (uint16_t *) sample; + int i = sizeof (*sample) / 2; + uint8_t single = HMC5883_MODE_SINGLE; + + ao_hmc5883_done = 0; + ao_exti_enable(AO_HMC5883_INT_PORT, AO_HMC5883_INT_PIN); + ao_hmc5883_reg_write(HMC5883_MODE, HMC5883_MODE_SINGLE); + + ao_alarm(AO_MS_TO_TICKS(10)); + cli(); + while (!ao_hmc5883_done) + if (ao_sleep(&ao_hmc5883_done)) + ++ao_hmc5883_missed_irq; + sei(); + ao_clear_alarm(); + + ao_hmc5883_read(HMC5883_X_MSB, (uint8_t *) sample, sizeof (struct ao_hmc5883_sample)); +#if __BYTE_ORDER == __LITTLE_ENDIAN + /* byte swap */ + while (i--) { + uint16_t t = *d; + *d++ = (t >> 8) | (t << 8); + } +#endif +} + +static uint8_t +ao_hmc5883_setup(void) +{ + uint8_t d; + uint8_t present; + + if (ao_hmc5883_configured) + return 1; + + ao_i2c_get(AO_HMC5883_I2C_INDEX); + present = ao_i2c_start(AO_HMC5883_I2C_INDEX, HMC5883_ADDR_READ); + ao_i2c_recv(&d, 1, AO_HMC5883_I2C_INDEX, TRUE); + ao_i2c_put(AO_HMC5883_I2C_INDEX); + + if (!present) + ao_panic(AO_PANIC_SELF_TEST); + + ao_hmc5883_reg_write(HMC5883_CONFIG_A, + (HMC5883_CONFIG_A_MA_8 << HMC5883_CONFIG_A_MA) | + (HMC5883_CONFIG_A_DO_15 << HMC5883_CONFIG_A_DO) | + (HMC5883_CONFIG_A_MS_NORMAL << HMC5883_CONFIG_A_MS)); + + ao_hmc5883_reg_write(HMC5883_CONFIG_B, + (HMC5883_CONFIG_B_GN_1_3 << HMC5883_CONFIG_B_GN)); + + ao_hmc5883_configured = 1; + return 1; +} + +static void +ao_hmc5883(void) +{ + ao_hmc5883_setup(); + for (;;) { + ao_hmc5883_sample((struct ao_hmc5883_sample *) &ao_data_ring[ao_data_head].hmc5883); + ao_arch_critical( + AO_DATA_PRESENT(AO_DATA_HMC5883); + AO_DATA_WAIT(); + ); + } +} + +static struct ao_task ao_hmc5883_task; + +static void +ao_hmc5883_show(void) +{ + struct ao_data sample; + ao_data_get(&sample); + printf ("X: %d Y: %d Z: %d missed irq: %lu\n", + sample.hmc5883.x, sample.hmc5883.y, sample.hmc5883.z, ao_hmc5883_missed_irq); +} + +static const struct ao_cmds ao_hmc5883_cmds[] = { + { ao_hmc5883_show, "M\0Show HMC5883 status" }, + { 0, NULL } +}; + +void +ao_hmc5883_init(void) +{ + ao_hmc5883_configured = 0; + + ao_enable_port(AO_HMC5883_INT_PORT); + ao_exti_setup(AO_HMC5883_INT_PORT, + AO_HMC5883_INT_PIN, + AO_EXTI_MODE_FALLING | AO_EXTI_MODE_PULL_UP, + ao_hmc5883_isr); + + ao_add_task(&ao_hmc5883_task, ao_hmc5883, "hmc5883"); + ao_cmd_register(&ao_hmc5883_cmds[0]); +} + +#endif |