On Sun, 1 Mar 2020 20:28:03 +0100
Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
> Disable MIPI I3C during device reset in order to avoid
> possible races on interrupt line 1. If the first interrupt
> line is asserted during hw reset the device will work in
> I3C-only mode
>
> Reported-by: Mario Tesi <mario.tesi@xxxxxx>
> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
Fixes tag?
One trivial thing inline.
Is this something we should be looking to have applied to stable?
Jonathan
> ---
> I have not been able to test this patch on a I3C device, just SPI/I2C
> ---
> drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h | 2 ++
> drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 30 ++++++++++++++++++++
> 2 files changed, 32 insertions(+)
>
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> index f2113a63721a..dfcbe7c42493 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> @@ -266,6 +266,7 @@ struct st_lsm6dsx_ext_dev_settings {
> * @wai: Sensor WhoAmI default value.
> * @reset: register address for reset.
> * @boot: register address for boot.
> + * @i3c_disable: register address for enabling/disabling I3C (addr + mask).
> * @bdu: register address for Block Data Update.
> * @max_fifo_size: Sensor max fifo length in FIFO words.
> * @id: List of hw id/device name supported by the driver configuration.
> @@ -284,6 +285,7 @@ struct st_lsm6dsx_settings {
> u8 wai;
> struct st_lsm6dsx_reg reset;
> struct st_lsm6dsx_reg boot;
> + struct st_lsm6dsx_reg i3c_disable;
> struct st_lsm6dsx_reg bdu;
> u16 max_fifo_size;
> struct {
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> index 84d219ae6aee..b1435c5d2d6d 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> @@ -751,6 +751,10 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
> .addr = 0x12,
> .mask = BIT(7),
> },
> + .i3c_disable = {
> + .addr = 0x18,
> + .mask = BIT(1),
> + },
> .bdu = {
> .addr = 0x12,
> .mask = BIT(6),
> @@ -1128,6 +1132,10 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
> .addr = 0x12,
> .mask = BIT(7),
> },
> + .i3c_disable = {
> + .addr = 0x18,
> + .mask = BIT(1),
> + },
> .bdu = {
> .addr = 0x12,
> .mask = BIT(6),
> @@ -2041,6 +2049,19 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
> const struct st_lsm6dsx_reg *reg;
> int err;
>
> + /* disable MIPI I3C during device reset in order to avoid
comment syntax
/*
* disable...
> + * possible races on interrupt line 1. If the first interrupt
> + * line is asserted during hw reset the device will work in
> + * I3C-only mode
> + */
> + if (hw->settings->i3c_disable.addr) {
> + reg = &hw->settings->i3c_disable;
> + err = regmap_update_bits(hw->regmap, reg->addr, reg->mask,
> + ST_LSM6DSX_SHIFT_VAL(1, reg->mask));
> + if (err < 0)
> + return err;
> + }
> +
> /* device sw reset */
> reg = &hw->settings->reset;
> err = regmap_update_bits(hw->regmap, reg->addr, reg->mask,
> @@ -2059,6 +2080,15 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
>
> msleep(50);
>
> + /* enable MIPI I3C */
> + if (hw->settings->i3c_disable.addr) {
> + reg = &hw->settings->i3c_disable;
> + err = regmap_update_bits(hw->regmap, reg->addr, reg->mask,
> + ST_LSM6DSX_SHIFT_VAL(0, reg->mask));
> + if (err < 0)
> + return err;
> + }
> +
> /* enable Block Data Update */
> reg = &hw->settings->bdu;
> err = regmap_update_bits(hw->regmap, reg->addr, reg->mask,
