[PATCH 1/2] thermal: rockchip: enhance the tsadc's bandgap feature for rk3399

[Caesar Wang]

From: Rocky Hao <rocky.hao at rock-chips.com>

Due to the voltage ripple, the sensing data of the tsadc is not accurate.
And in this patch, the bandgap feature is enhanced to remove the voltage
ripple, and then the tsadc can sense the temperature more precisely.

Obsolete codes are removed as well.

Signed-off-by: Rocky Hao <rocky.hao at rock-chips.com>
Signed-off-by: Caesar Wang <wxt at rock-chips.com>
Cc: Eduardo Valentin <edubezval at gmail.com>
Cc: Zhang Rui <rui.zhang at intel.com>
Cc: Heiko Stuebner <heiko at sntech.de>
Cc: linux-pm at vger.kernel.org
---

 drivers/thermal/rockchip_thermal.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c
index db5ecc5..a90423d 100644
--- a/drivers/thermal/rockchip_thermal.c
+++ b/drivers/thermal/rockchip_thermal.c
@@ -222,10 +222,10 @@ struct rockchip_thermal_data {
 #define GRF_TSADC_TESTBIT_L			0x0e648
 #define GRF_TSADC_TESTBIT_H			0x0e64c
 
-#define GRF_TSADC_TSEN_PD_ON			(0x30003 << 0)
-#define GRF_TSADC_TSEN_PD_OFF			(0x30000 << 0)
 #define GRF_SARADC_TESTBIT_ON			(0x10001 << 2)
 #define GRF_TSADC_TESTBIT_H_ON			(0x10001 << 2)
+#define GRF_TSADC_VCM_EN_L			(0x10001 << 7)
+#define GRF_TSADC_VCM_EN_H			(0x10001 << 7)
 
 /**
  * struct tsadc_table - code to temperature conversion table
@@ -567,9 +567,10 @@ static void rk_tsadcv3_initialize(struct regmap *grf, void __iomem *regs,
 			       regs + TSADCV2_HIGHT_TSHUT_DEBOUNCE);
 
 	} else {
-		regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_ON);
-		mdelay(10);
-		regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_OFF);
+		/* Enable the voltage common mode feature */
+		regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_VCM_EN_L);
+		regmap_write(grf, GRF_TSADC_TESTBIT_H, GRF_TSADC_VCM_EN_H);
+
 		usleep_range(15, 100); /* The spec note says at least 15 us */
 		regmap_write(grf, GRF_SARADC_TESTBIT, GRF_SARADC_TESTBIT_ON);
 		regmap_write(grf, GRF_TSADC_TESTBIT_H, GRF_TSADC_TESTBIT_H_ON);
-- 
1.9.1