altos: Update sensor data atomically

Read data into a temp variable, block interrupts, then update the
published value.

The bug is easy to see with the HMC5883 which has to byte-swap the
output of the chip, and hence can occasionally get caught with the
wrong byte order data.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/drivers/ao_hmc5883.c b/src/drivers/ao_hmc5883.c
index f668fb66e7435f720a08d20cb8d87291326ebb48..9f1131d6b607671883f2c933a35279e5ae59539b 100644 (file)
--- a/src/drivers/ao_hmc5883.c
+++ b/src/drivers/ao_hmc5883.c
@@ -126,13 +126,15 @@ struct ao_hmc5883_sample ao_hmc5883_current;
 static void
 ao_hmc5883(void)
 {
+       struct ao_hmc5883_sample        sample;
        ao_hmc5883_setup();
        for (;;) {
-               ao_hmc5883_sample(&ao_hmc5883_current);
-               ao_arch_critical(
-                       AO_DATA_PRESENT(AO_DATA_HMC5883);
-                       AO_DATA_WAIT();
-                       );
+               ao_hmc5883_sample(&sample);
+               ao_arch_block_interrupts();
+               ao_hmc5883_current = sample;
+               AO_DATA_PRESENT(AO_DATA_HMC5883);
+               AO_DATA_WAIT();
+               ao_arch_release_interrupts();
        }
 }
 

diff --git a/src/drivers/ao_mpu6000.c b/src/drivers/ao_mpu6000.c
index 650407ad8b679d8f98478e82e84da422b1c3bdce..81d3c16cc76479f3eb2298fb23292d0d3191714a 100644 (file)
--- a/src/drivers/ao_mpu6000.c
+++ b/src/drivers/ao_mpu6000.c
@@ -192,7 +192,7 @@ _ao_mpu6000_setup(void)
        _ao_mpu6000_wait_alive();
 
        /* Reset the whole chip */
-       
+
        _ao_mpu6000_reg_write(MPU6000_PWR_MGMT_1,
                              (1 << MPU6000_PWR_MGMT_1_DEVICE_RESET));
 
@@ -292,7 +292,7 @@ _ao_mpu6000_setup(void)
 
                ao_delay(AO_MS_TO_TICKS(200));
                _ao_mpu6000_sample(&normal_mode);
-       
+
                errors += ao_mpu6000_accel_check(normal_mode.accel_x, test_mode.accel_x);
                errors += ao_mpu6000_accel_check(normal_mode.accel_y, test_mode.accel_y);
                errors += ao_mpu6000_accel_check(normal_mode.accel_z, test_mode.accel_z);
@@ -315,7 +315,7 @@ _ao_mpu6000_setup(void)
        /* Set sample rate divider to sample at 200Hz (v = gyro/rate - 1) */
        _ao_mpu6000_reg_write(MPU6000_SMPRT_DIV,
                              1000 / 200 - 1);
-       
+
        ao_delay(AO_MS_TO_TICKS(100));
        ao_mpu6000_configured = 1;
 }
@@ -325,6 +325,7 @@ struct ao_mpu6000_sample    ao_mpu6000_current;
 static void
 ao_mpu6000(void)
 {
+       struct ao_mpu6000_sample        sample;
        /* ao_mpu6000_init already grabbed the SPI bus and mutex */
        _ao_mpu6000_setup();
 #if AO_MPU6000_SPI
@@ -335,14 +336,15 @@ ao_mpu6000(void)
 #if AO_MPU6000_SPI
                ao_mpu6000_spi_get();
 #endif
-               _ao_mpu6000_sample(&ao_mpu6000_current);
+               _ao_mpu6000_sample(&sample);
 #if AO_MPU6000_SPI
                ao_mpu6000_spi_put();
-#endif 
-               ao_arch_critical(
-                       AO_DATA_PRESENT(AO_DATA_MPU6000);
-                       AO_DATA_WAIT();
-                       );
+#endif
+               ao_arch_block_interrupts();
+               ao_mpu6000_current = sample;
+               AO_DATA_PRESENT(AO_DATA_MPU6000);
+               AO_DATA_WAIT();
+               ao_arch_release_interrupts();
        }
 }
 
@@ -351,16 +353,13 @@ static struct ao_task ao_mpu6000_task;
 static void
 ao_mpu6000_show(void)
 {
-       struct ao_data  sample;
-
-       ao_data_get(&sample);
        printf ("Accel: %7d %7d %7d Gyro: %7d %7d %7d\n",
-               sample.mpu6000.accel_x,
-               sample.mpu6000.accel_y,
-               sample.mpu6000.accel_z,
-               sample.mpu6000.gyro_x,
-               sample.mpu6000.gyro_y,
-               sample.mpu6000.gyro_z);
+               ao_mpu6000_current.accel_x,
+               ao_mpu6000_current.accel_y,
+               ao_mpu6000_current.accel_z,
+               ao_mpu6000_current.gyro_x,
+               ao_mpu6000_current.gyro_y,
+               ao_mpu6000_current.gyro_z);
 }
 
 static const struct ao_cmds ao_mpu6000_cmds[] = {
@@ -374,7 +373,7 @@ ao_mpu6000_init(void)
        ao_mpu6000_configured = 0;
 
        ao_add_task(&ao_mpu6000_task, ao_mpu6000, "mpu6000");
-       
+
 #if AO_MPU6000_SPI
        ao_spi_init_cs(AO_MPU6000_SPI_CS_PORT, (1 << AO_MPU6000_SPI_CS_PIN));
 
@@ -386,7 +385,7 @@ ao_mpu6000_init(void)
        ao_cur_task = &ao_mpu6000_task;
        ao_spi_get(AO_MPU6000_SPI_BUS, AO_SPI_SPEED_1MHz);
        ao_cur_task = NULL;
-#endif 
+#endif
 
        ao_cmd_register(&ao_mpu6000_cmds[0]);
 }

diff --git a/src/drivers/ao_ms5607.c b/src/drivers/ao_ms5607.c
index 0afdf01276b3a5d40337308a5058d1a99f297741..914e0c1b3c7b620ca40c23ee82f88c9ac5b5576e 100644 (file)
--- a/src/drivers/ao_ms5607.c
+++ b/src/drivers/ao_ms5607.c
@@ -201,11 +201,13 @@ __xdata struct ao_ms5607_sample   ao_ms5607_current;
 static void
 ao_ms5607(void)
 {
+       struct ao_ms5607_sample sample;
        ao_ms5607_setup();
        for (;;)
        {
-               ao_ms5607_sample(&ao_ms5607_current);
+               ao_ms5607_sample(&sample);
                ao_arch_block_interrupts();
+               ao_ms5607_current = sample;
                AO_DATA_PRESENT(AO_DATA_MS5607);
                AO_DATA_WAIT();
                ao_arch_release_interrupts();