+/*
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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_mpu9250.h>
+#include <ao_exti.h>
+
+#if HAS_MPU9250
+
+static uint8_t ao_mpu9250_configured;
+
+extern uint8_t ao_sensor_errors;
+
+#ifndef AO_MPU9250_I2C_INDEX
+#define AO_MPU9250_SPI 1
+#else
+#define AO_MPU9250_SPI 0
+#endif
+
+#if AO_MPU9250_SPI
+
+#define ao_mpu9250_spi_get() ao_spi_get(AO_MPU9250_SPI_BUS, AO_SPI_SPEED_1MHz)
+#define ao_mpu9250_spi_put() ao_spi_put(AO_MPU9250_SPI_BUS)
+
+#define ao_mpu9250_spi_start() ao_spi_set_cs(AO_MPU9250_SPI_CS_PORT, \
+ (1 << AO_MPU9250_SPI_CS_PIN))
+
+#define ao_mpu9250_spi_end() ao_spi_clr_cs(AO_MPU9250_SPI_CS_PORT, \
+ (1 << AO_MPU9250_SPI_CS_PIN))
+
+#endif
+
+
+static void
+_ao_mpu9250_reg_write(uint8_t addr, uint8_t value)
+{
+ uint8_t d[2] = { addr, value };
+#if AO_MPU9250_SPI
+ ao_mpu9250_spi_start();
+ ao_spi_send(d, 2, AO_MPU9250_SPI_BUS);
+ ao_mpu9250_spi_end();
+#else
+ ao_i2c_get(AO_MPU9250_I2C_INDEX);
+ ao_i2c_start(AO_MPU9250_I2C_INDEX, MPU9250_ADDR_WRITE);
+ ao_i2c_send(d, 2, AO_MPU9250_I2C_INDEX, TRUE);
+ ao_i2c_put(AO_MPU9250_I2C_INDEX);
+#endif
+}
+
+static void
+_ao_mpu9250_read(uint8_t addr, void *data, uint8_t len)
+{
+#if AO_MPU9250_SPI
+ addr |= 0x80;
+ ao_mpu9250_spi_start();
+ ao_spi_send(&addr, 1, AO_MPU9250_SPI_BUS);
+ ao_spi_recv(data, len, AO_MPU9250_SPI_BUS);
+ ao_mpu9250_spi_end();
+#else
+ ao_i2c_get(AO_MPU9250_I2C_INDEX);
+ ao_i2c_start(AO_MPU9250_I2C_INDEX, MPU9250_ADDR_WRITE);
+ ao_i2c_send(&addr, 1, AO_MPU9250_I2C_INDEX, FALSE);
+ ao_i2c_start(AO_MPU9250_I2C_INDEX, MPU9250_ADDR_READ);
+ ao_i2c_recv(data, len, AO_MPU9250_I2C_INDEX, TRUE);
+ ao_i2c_put(AO_MPU9250_I2C_INDEX);
+#endif
+}
+
+static uint8_t
+_ao_mpu9250_reg_read(uint8_t addr)
+{
+ uint8_t value;
+#if AO_MPU9250_SPI
+ addr |= 0x80;
+ ao_mpu9250_spi_start();
+ ao_spi_send(&addr, 1, AO_MPU9250_SPI_BUS);
+ ao_spi_recv(&value, 1, AO_MPU9250_SPI_BUS);
+ ao_mpu9250_spi_end();
+#else
+ ao_i2c_get(AO_MPU9250_I2C_INDEX);
+ ao_i2c_start(AO_MPU9250_I2C_INDEX, MPU9250_ADDR_WRITE);
+ ao_i2c_send(&addr, 1, AO_MPU9250_I2C_INDEX, FALSE);
+ ao_i2c_start(AO_MPU9250_I2C_INDEX, MPU9250_ADDR_READ);
+ ao_i2c_recv(&value, 1, AO_MPU9250_I2C_INDEX, TRUE);
+ ao_i2c_put(AO_MPU9250_I2C_INDEX);
+#endif
+ return value;
+}
+
+static void
+_ao_mpu9250_sample(struct ao_mpu9250_sample *sample)
+{
+ uint16_t *d = (uint16_t *) sample;
+ int i = sizeof (*sample) / 2;
+
+ _ao_mpu9250_read(MPU9250_ACCEL_XOUT_H, sample, sizeof (*sample));
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ /* byte swap */
+ while (i--) {
+ uint16_t t = *d;
+ *d++ = (t >> 8) | (t << 8);
+ }
+#endif
+}
+
+#define G 981 /* in cm/s² */
+
+#if 0
+static int16_t /* cm/s² */
+ao_mpu9250_accel(int16_t v)
+{
+ return (int16_t) ((v * (int32_t) (16.0 * 980.665 + 0.5)) / 32767);
+}
+
+static int16_t /* deg*10/s */
+ao_mpu9250_gyro(int16_t v)
+{
+ return (int16_t) ((v * (int32_t) 20000) / 32767);
+}
+#endif
+
+static uint8_t
+ao_mpu9250_accel_check(int16_t normal, int16_t test)
+{
+ int16_t diff = test - normal;
+
+ if (diff < MPU9250_ST_ACCEL(16) / 4) {
+ return 1;
+ }
+ if (diff > MPU9250_ST_ACCEL(16) * 4) {
+ return 1;
+ }
+ return 0;
+}
+
+static uint8_t
+ao_mpu9250_gyro_check(int16_t normal, int16_t test)
+{
+ int16_t diff = test - normal;
+
+ if (diff < 0)
+ diff = -diff;
+ if (diff < MPU9250_ST_GYRO(2000) / 4) {
+ return 1;
+ }
+ if (diff > MPU9250_ST_GYRO(2000) * 4) {
+ return 1;
+ }
+ return 0;
+}
+
+static void
+_ao_mpu9250_wait_alive(void)
+{
+ uint8_t i;
+
+ /* Wait for the chip to wake up */
+ for (i = 0; i < 30; i++) {
+ ao_delay(AO_MS_TO_TICKS(100));
+ if (_ao_mpu9250_reg_read(MPU9250_WHO_AM_I) == MPU9250_I_AM_9250)
+ break;
+ }
+ if (i == 30)
+ ao_panic(AO_PANIC_SELF_TEST_MPU9250);
+}
+
+#define ST_TRIES 10
+
+static void
+_ao_mpu9250_setup(void)
+{
+ struct ao_mpu9250_sample normal_mode, test_mode;
+ int errors;
+ int st_tries;
+
+ if (ao_mpu9250_configured)
+ return;
+
+ _ao_mpu9250_wait_alive();
+
+ /* Reset the whole chip */
+
+ _ao_mpu9250_reg_write(MPU9250_PWR_MGMT_1,
+ (1 << MPU9250_PWR_MGMT_1_DEVICE_RESET));
+
+ /* Wait for it to reset. If we talk too quickly, it appears to get confused */
+
+ _ao_mpu9250_wait_alive();
+
+ /* Reset signal conditioning, disabling I2C on SPI systems */
+ _ao_mpu9250_reg_write(MPU9250_USER_CTRL,
+ (0 << MPU9250_USER_CTRL_FIFO_EN) |
+ (0 << MPU9250_USER_CTRL_I2C_MST_EN) |
+ (AO_MPU9250_SPI << MPU9250_USER_CTRL_I2C_IF_DIS) |
+ (0 << MPU9250_USER_CTRL_FIFO_RESET) |
+ (0 << MPU9250_USER_CTRL_I2C_MST_RESET) |
+ (1 << MPU9250_USER_CTRL_SIG_COND_RESET));
+
+ while (_ao_mpu9250_reg_read(MPU9250_USER_CTRL) & (1 << MPU9250_USER_CTRL_SIG_COND_RESET))
+ ao_delay(AO_MS_TO_TICKS(10));
+
+ /* Reset signal paths */
+ _ao_mpu9250_reg_write(MPU9250_SIGNAL_PATH_RESET,
+ (1 << MPU9250_SIGNAL_PATH_RESET_GYRO_RESET) |
+ (1 << MPU9250_SIGNAL_PATH_RESET_ACCEL_RESET) |
+ (1 << MPU9250_SIGNAL_PATH_RESET_TEMP_RESET));
+
+ _ao_mpu9250_reg_write(MPU9250_SIGNAL_PATH_RESET,
+ (0 << MPU9250_SIGNAL_PATH_RESET_GYRO_RESET) |
+ (0 << MPU9250_SIGNAL_PATH_RESET_ACCEL_RESET) |
+ (0 << MPU9250_SIGNAL_PATH_RESET_TEMP_RESET));
+
+ /* Select clocks, disable sleep */
+ _ao_mpu9250_reg_write(MPU9250_PWR_MGMT_1,
+ (0 << MPU9250_PWR_MGMT_1_DEVICE_RESET) |
+ (0 << MPU9250_PWR_MGMT_1_SLEEP) |
+ (0 << MPU9250_PWR_MGMT_1_CYCLE) |
+ (0 << MPU9250_PWR_MGMT_1_TEMP_DIS) |
+ (MPU9250_PWR_MGMT_1_CLKSEL_PLL_X_AXIS << MPU9250_PWR_MGMT_1_CLKSEL));
+
+ /* Set sample rate divider to sample at full speed */
+ _ao_mpu9250_reg_write(MPU9250_SMPRT_DIV, 0);
+
+ /* Disable filtering */
+ _ao_mpu9250_reg_write(MPU9250_CONFIG,
+ (MPU9250_CONFIG_EXT_SYNC_SET_DISABLED << MPU9250_CONFIG_EXT_SYNC_SET) |
+ (MPU9250_CONFIG_DLPF_CFG_250 << MPU9250_CONFIG_DLPF_CFG));
+
+ for (st_tries = 0; st_tries < ST_TRIES; st_tries++) {
+ errors = 0;
+
+ /* Configure accelerometer to +/-16G in self-test mode */
+ _ao_mpu9250_reg_write(MPU9250_ACCEL_CONFIG,
+ (1 << MPU9250_ACCEL_CONFIG_XA_ST) |
+ (1 << MPU9250_ACCEL_CONFIG_YA_ST) |
+ (1 << MPU9250_ACCEL_CONFIG_ZA_ST) |
+ (MPU9250_ACCEL_CONFIG_AFS_SEL_16G << MPU9250_ACCEL_CONFIG_AFS_SEL));
+
+ /* Configure gyro to +/- 2000°/s in self-test mode */
+ _ao_mpu9250_reg_write(MPU9250_GYRO_CONFIG,
+ (1 << MPU9250_GYRO_CONFIG_XG_ST) |
+ (1 << MPU9250_GYRO_CONFIG_YG_ST) |
+ (1 << MPU9250_GYRO_CONFIG_ZG_ST) |
+ (MPU9250_GYRO_CONFIG_FS_SEL_2000 << MPU9250_GYRO_CONFIG_FS_SEL));
+
+ ao_delay(AO_MS_TO_TICKS(200));
+ _ao_mpu9250_sample(&test_mode);
+
+ /* Configure accelerometer to +/-16G */
+ _ao_mpu9250_reg_write(MPU9250_ACCEL_CONFIG,
+ (0 << MPU9250_ACCEL_CONFIG_XA_ST) |
+ (0 << MPU9250_ACCEL_CONFIG_YA_ST) |
+ (0 << MPU9250_ACCEL_CONFIG_ZA_ST) |
+ (MPU9250_ACCEL_CONFIG_AFS_SEL_16G << MPU9250_ACCEL_CONFIG_AFS_SEL));
+
+ /* Configure gyro to +/- 2000°/s */
+ _ao_mpu9250_reg_write(MPU9250_GYRO_CONFIG,
+ (0 << MPU9250_GYRO_CONFIG_XG_ST) |
+ (0 << MPU9250_GYRO_CONFIG_YG_ST) |
+ (0 << MPU9250_GYRO_CONFIG_ZG_ST) |
+ (MPU9250_GYRO_CONFIG_FS_SEL_2000 << MPU9250_GYRO_CONFIG_FS_SEL));
+
+ ao_delay(AO_MS_TO_TICKS(200));
+ _ao_mpu9250_sample(&normal_mode);
+
+ errors += ao_mpu9250_accel_check(normal_mode.accel_x, test_mode.accel_x);
+ errors += ao_mpu9250_accel_check(normal_mode.accel_y, test_mode.accel_y);
+ errors += ao_mpu9250_accel_check(normal_mode.accel_z, test_mode.accel_z);
+
+ errors += ao_mpu9250_gyro_check(normal_mode.gyro_x, test_mode.gyro_x);
+ errors += ao_mpu9250_gyro_check(normal_mode.gyro_y, test_mode.gyro_y);
+ errors += ao_mpu9250_gyro_check(normal_mode.gyro_z, test_mode.gyro_z);
+ if (!errors)
+ break;
+ }
+
+ if (st_tries == ST_TRIES)
+ ao_sensor_errors = 1;
+
+ /* Filter to about 100Hz, which also sets the gyro rate to 1000Hz */
+ _ao_mpu9250_reg_write(MPU9250_CONFIG,
+ (MPU9250_CONFIG_FIFO_MODE_REPLACE << MPU9250_CONFIG_FIFO_MODE) |
+ (MPU9250_CONFIG_EXT_SYNC_SET_DISABLED << MPU9250_CONFIG_EXT_SYNC_SET) |
+ (MPU9250_CONFIG_DLPF_CFG_92 << MPU9250_CONFIG_DLPF_CFG));
+
+ /* Set sample rate divider to sample at 200Hz (v = gyro/rate - 1) */
+ _ao_mpu9250_reg_write(MPU9250_SMPRT_DIV,
+ 1000 / 200 - 1);
+
+ ao_delay(AO_MS_TO_TICKS(100));
+ ao_mpu9250_configured = 1;
+}
+
+struct ao_mpu9250_sample ao_mpu9250_current;
+
+static void
+ao_mpu9250(void)
+{
+ struct ao_mpu9250_sample sample;
+ /* ao_mpu9250_init already grabbed the SPI bus and mutex */
+ _ao_mpu9250_setup();
+#if AO_MPU9250_SPI
+ ao_mpu9250_spi_put();
+#endif
+ for (;;)
+ {
+#if AO_MPU9250_SPI
+ ao_mpu9250_spi_get();
+#endif
+ _ao_mpu9250_sample(&sample);
+#if AO_MPU9250_SPI
+ ao_mpu9250_spi_put();
+#endif
+ ao_arch_block_interrupts();
+ ao_mpu9250_current = sample;
+ AO_DATA_PRESENT(AO_DATA_MPU9250);
+ AO_DATA_WAIT();
+ ao_arch_release_interrupts();
+ }
+}
+
+static struct ao_task ao_mpu9250_task;
+
+static void
+ao_mpu9250_show(void)
+{
+ printf ("Accel: %7d %7d %7d Gyro: %7d %7d %7d\n",
+ ao_mpu9250_current.accel_x,
+ ao_mpu9250_current.accel_y,
+ ao_mpu9250_current.accel_z,
+ ao_mpu9250_current.gyro_x,
+ ao_mpu9250_current.gyro_y,
+ ao_mpu9250_current.gyro_z);
+}
+
+static void
+ao_mpu9250_read(void)
+{
+ uint8_t addr;
+ uint8_t val;
+
+ ao_cmd_hex();
+ if (ao_cmd_status != ao_cmd_success)
+ return;
+ addr = ao_cmd_lex_i;
+ ao_mpu9250_spi_get();
+ val = _ao_mpu9250_reg_read(addr);
+ ao_mpu9250_spi_put();
+ printf("Addr %02x val %02x\n", addr, val);
+}
+
+static void
+ao_mpu9250_write(void)
+{
+ uint8_t addr;
+ uint8_t val;
+
+ ao_cmd_hex();
+ if (ao_cmd_status != ao_cmd_success)
+ return;
+ addr = ao_cmd_lex_i;
+ ao_cmd_hex();
+ if (ao_cmd_status != ao_cmd_success)
+ return;
+ val = ao_cmd_lex_i;
+ printf("Addr %02x val %02x\n", addr, val);
+ ao_mpu9250_spi_get();
+ _ao_mpu9250_reg_write(addr, val);
+ ao_mpu9250_spi_put();
+}
+
+static const struct ao_cmds ao_mpu9250_cmds[] = {
+ { ao_mpu9250_show, "I\0Show MPU9250 status" },
+ { ao_mpu9250_read, "R <addr>\0Read MPU9250 register" },
+ { ao_mpu9250_write, "W <addr> <val>\0Write MPU9250 register" },
+ { 0, NULL }
+};
+
+void
+ao_mpu9250_init(void)
+{
+ ao_mpu9250_configured = 0;
+
+ ao_add_task(&ao_mpu9250_task, ao_mpu9250, "mpu9250");
+
+#if AO_MPU9250_SPI
+ ao_spi_init_cs(AO_MPU9250_SPI_CS_PORT, (1 << AO_MPU9250_SPI_CS_PIN));
+
+ /* Pretend to be the mpu9250 task. Grab the SPI bus right away and
+ * hold it for the task so that nothing else uses the SPI bus before
+ * we get the I2C mode disabled in the chip
+ */
+
+ ao_cur_task = &ao_mpu9250_task;
+ ao_spi_get(AO_MPU9250_SPI_BUS, AO_SPI_SPEED_1MHz);
+ ao_cur_task = NULL;
+#endif
+ ao_cmd_register(&ao_mpu9250_cmds[0]);
+}
+#endif