hwmon: lis3: Power on corrections

Sometimes lis3 chip seems to fail to setup factory tuning at boot up.
This probably happens if there is some odd power ramp down ramp up sequence
for example in device restart. Set boot bit in control2 register to
trig boot sequence manually and wait until it is finished.

Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c
index 1095dff9b200e8dfe4b0869702235d78eb13fc42..7448411f51eaa7272094ecceb6c37d4ba4f86ed9 100644 (file)
--- a/drivers/hwmon/lis3lv02d.c
+++ b/drivers/hwmon/lis3lv02d.c
@@ -307,19 +307,22 @@ void lis3lv02d_poweron(struct lis3lv02d *lis3)
 
        lis3->init(lis3);
 
-       /* LIS3 power on delay is quite long */
-       msleep(lis3->pwron_delay / lis3lv02d_get_odr());
-
        /*
         * Common configuration
         * BDU: (12 bits sensors only) LSB and MSB values are not updated until
         *      both have been read. So the value read will always be correct.
+        * Set BOOT bit to refresh factory tuning values.
         */
-       if (lis3->whoami ==  WAI_12B) {
-               lis3->read(lis3, CTRL_REG2, &reg);
-               reg |= CTRL2_BDU;
-               lis3->write(lis3, CTRL_REG2, reg);
-       }
+       lis3->read(lis3, CTRL_REG2, &reg);
+       if (lis3->whoami ==  WAI_12B)
+               reg |= CTRL2_BDU | CTRL2_BOOT;
+       else
+               reg |= CTRL2_BOOT_8B;
+       lis3->write(lis3, CTRL_REG2, reg);
+
+       /* LIS3 power on delay is quite long */
+       msleep(lis3->pwron_delay / lis3lv02d_get_odr());
+
        if (lis3->reg_ctrl)
                lis3_context_restore(lis3);
 }

diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h
index e54a1672ae64d938b1880fc081a371f146e1781c..77ebb15ea0b3cd4396ce722336573d2dfbfe4951 100644 (file)
--- a/drivers/hwmon/lis3lv02d.h
+++ b/drivers/hwmon/lis3lv02d.h
@@ -150,6 +150,7 @@ enum lis3lv02d_ctrl4_3dc {
 enum lis302d_ctrl2 {
        HP_FF_WU2       = 0x08,
        HP_FF_WU1       = 0x04,
+       CTRL2_BOOT_8B   = 0x40,
 };
 
 enum lis3lv02d_ctrl3 {