[PATCH v3 08/19] media: i2c: ds90ub953: Speed-up I2C watchdog timer

[Jai Luthra]

On the I2C bus for remote clients (sensors), by default the watchdog
timer expires in 1s. To allow for a quicker system bring-up time, TI
recommends to speed it up to 50us [1].

[1]: Section 7.3.1.1 - https://www.ti.com/lit/gpn/ds90ub953-q1

Signed-off-by: Jai Luthra <jai.luthra@xxxxxxxxxxxxxxxx>
---
Changes from v2:
- Use unsigned value for left shifting
- Re-introduce temp variable v that was dropped as it makes it easier to
  read IMHO
- Remove redundancies like initializing v = 0 and if (ret) return ret at
  the end of the function
---
 drivers/media/i2c/ds90ub953.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ds90ub953.c b/drivers/media/i2c/ds90ub953.c
index a08aad3f7fe09f7b396da9c720ed9993d392410c..a5c23e94f4eab5896a2114cfdf2e5f68cde77568 100644
--- a/drivers/media/i2c/ds90ub953.c
+++ b/drivers/media/i2c/ds90ub953.c
@@ -54,6 +54,10 @@
 #define UB953_REG_CLKOUT_CTRL0			0x06
 #define UB953_REG_CLKOUT_CTRL1			0x07
 
+#define UB953_REG_I2C_CONTROL2			0x0a
+#define UB953_REG_I2C_CONTROL2_SDA_OUTPUT_SETUP_SHIFT	4
+#define UB953_REG_I2C_CONTROL2_BUS_SPEEDUP	BIT(1)
+
 #define UB953_REG_SCL_HIGH_TIME			0x0b
 #define UB953_REG_SCL_LOW_TIME			0x0c
 
@@ -1320,7 +1324,12 @@ static int ub953_hw_init(struct ub953_data *priv)
 	if (ret)
 		return ret;
 
-	return 0;
+	v = 1U << UB953_REG_I2C_CONTROL2_SDA_OUTPUT_SETUP_SHIFT;
+	v |= UB953_REG_I2C_CONTROL2_BUS_SPEEDUP;
+
+	ret = ub953_write(priv, UB953_REG_I2C_CONTROL2, v, NULL);
+
+	return ret;
 }
 
 static int ub953_subdev_init(struct ub953_data *priv)

-- 
2.48.1