diff mbox series

[2/7] iio: imu: st_lsm6dsx: reboot memory content after reset

Message ID 71f6b6a308a74c863926a9de28cf51d42d26b859.1541341926.git.lorenzo.bianconi@redhat.com (mailing list archive)
State New, archived
Headers show
Series add i2c controller support to st_lsm6dsx driver | expand

Commit Message

Lorenzo Bianconi Nov. 4, 2018, 2:39 p.m. UTC
Perform a memory content reboot after device reset

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

Comments

Jonathan Cameron Nov. 4, 2018, 5:12 p.m. UTC | #1
On Sun,  4 Nov 2018 15:39:01 +0100
Lorenzo Bianconi <lorenzo.bianconi@redhat.com> wrote:

> Perform a memory content reboot after device reset
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
> ---
>  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> index c8b993bea757..e3ebd04d8078 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> @@ -56,6 +56,7 @@
>  #define ST_LSM6DSX_REG_WHOAMI_ADDR		0x0f
>  #define ST_LSM6DSX_REG_RESET_ADDR		0x12
>  #define ST_LSM6DSX_REG_RESET_MASK		BIT(0)
> +#define ST_LSM6DSX_REG_BOOT_MASK		BIT(7)
>  #define ST_LSM6DSX_REG_BDU_ADDR			0x12
>  #define ST_LSM6DSX_REG_BDU_MASK			BIT(6)
>  #define ST_LSM6DSX_REG_INT2_ON_INT1_ADDR	0x13
> @@ -778,12 +779,21 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
>  	u8 drdy_int_reg;
>  	int err;
>  
> -	err = regmap_write(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
> -			   ST_LSM6DSX_REG_RESET_MASK);
> +	err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
> +				 ST_LSM6DSX_REG_RESET_MASK,
> +				 FIELD_PREP(ST_LSM6DSX_REG_RESET_MASK, 1));
>  	if (err < 0)
>  		return err;
>  
> -	msleep(200);
> +	msleep(50);
> +
> +	err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
> +				 ST_LSM6DSX_REG_BOOT_MASK,
> +				 FIELD_PREP(ST_LSM6DSX_REG_BOOT_MASK, 1));
> +	if (err < 0)
> +		return err;
> +
> +	msleep(50);
This change in the timing needs an explanatory comment in the patch
description.


>  
>  	/* enable Block Data Update */
>  	err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_BDU_ADDR,
Lorenzo Bianconi Nov. 4, 2018, 5:30 p.m. UTC | #2
>
> On Sun,  4 Nov 2018 15:39:01 +0100
> Lorenzo Bianconi <lorenzo.bianconi@redhat.com> wrote:
>
> > Perform a memory content reboot after device reset
> >
> > Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
> > ---
> >  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 16 +++++++++++++---
> >  1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > index c8b993bea757..e3ebd04d8078 100644
> > --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> > @@ -56,6 +56,7 @@
> >  #define ST_LSM6DSX_REG_WHOAMI_ADDR           0x0f
> >  #define ST_LSM6DSX_REG_RESET_ADDR            0x12
> >  #define ST_LSM6DSX_REG_RESET_MASK            BIT(0)
> > +#define ST_LSM6DSX_REG_BOOT_MASK             BIT(7)
> >  #define ST_LSM6DSX_REG_BDU_ADDR                      0x12
> >  #define ST_LSM6DSX_REG_BDU_MASK                      BIT(6)
> >  #define ST_LSM6DSX_REG_INT2_ON_INT1_ADDR     0x13
> > @@ -778,12 +779,21 @@ static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
> >       u8 drdy_int_reg;
> >       int err;
> >
> > -     err = regmap_write(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
> > -                        ST_LSM6DSX_REG_RESET_MASK);
> > +     err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
> > +                              ST_LSM6DSX_REG_RESET_MASK,
> > +                              FIELD_PREP(ST_LSM6DSX_REG_RESET_MASK, 1));
> >       if (err < 0)
> >               return err;
> >
> > -     msleep(200);
> > +     msleep(50);
> > +
> > +     err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
> > +                              ST_LSM6DSX_REG_BOOT_MASK,
> > +                              FIELD_PREP(ST_LSM6DSX_REG_BOOT_MASK, 1));
> > +     if (err < 0)
> > +             return err;
> > +
> > +     msleep(50);
> This change in the timing needs an explanatory comment in the patch
> description.
>
>
> >
> >       /* enable Block Data Update */
> >       err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_BDU_ADDR,
>

Hi Jonathan,

This patch reloads the trimming parameters to perform a complete reset
of the device. Full explanation can be read here:
https://www.st.com/resource/en/application_note/dm00517282.pdf, section 5.7.
I will add a proper description in v2, thx

Regards,
Lorenzo
diff mbox series

Patch

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
index c8b993bea757..e3ebd04d8078 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -56,6 +56,7 @@ 
 #define ST_LSM6DSX_REG_WHOAMI_ADDR		0x0f
 #define ST_LSM6DSX_REG_RESET_ADDR		0x12
 #define ST_LSM6DSX_REG_RESET_MASK		BIT(0)
+#define ST_LSM6DSX_REG_BOOT_MASK		BIT(7)
 #define ST_LSM6DSX_REG_BDU_ADDR			0x12
 #define ST_LSM6DSX_REG_BDU_MASK			BIT(6)
 #define ST_LSM6DSX_REG_INT2_ON_INT1_ADDR	0x13
@@ -778,12 +779,21 @@  static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
 	u8 drdy_int_reg;
 	int err;
 
-	err = regmap_write(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
-			   ST_LSM6DSX_REG_RESET_MASK);
+	err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
+				 ST_LSM6DSX_REG_RESET_MASK,
+				 FIELD_PREP(ST_LSM6DSX_REG_RESET_MASK, 1));
 	if (err < 0)
 		return err;
 
-	msleep(200);
+	msleep(50);
+
+	err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_RESET_ADDR,
+				 ST_LSM6DSX_REG_BOOT_MASK,
+				 FIELD_PREP(ST_LSM6DSX_REG_BOOT_MASK, 1));
+	if (err < 0)
+		return err;
+
+	msleep(50);
 
 	/* enable Block Data Update */
 	err = regmap_update_bits(hw->regmap, ST_LSM6DSX_REG_BDU_ADDR,