power: pmic: tps65218: Fix tps65218_voltage_update function

Currently while setting the vsel value for dcdc1 and dcdc2
the driver is wrongly masking the entire 8 bits in the process
clearing PFM (bit7) field as well. Hence describe an appropriate
mask for vsel field and modify only those bits in the vsel
mask.

Source: http://www.ti.com/lit/ds/symlink/tps65218.pdf

Signed-off-by: Keerthy <j-keerthy@ti.com>
Fixes: 86db550b38 ("power: Add support for the TPS65218 PMIC")
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

drivers/power/pmic/pmic_tps65218.c

@@ -101,7 +101,7 @@ int tps65218_voltage_update(uchar dc_cntrl_reg, uchar volt_sel)
 
 	/* set voltage level */
 	if (tps65218_reg_write(TPS65218_PROT_LEVEL_2, dc_cntrl_reg, volt_sel,
-			       TPS65218_MASK_ALL_BITS))
+			       TPS65218_DCDC_VSEL_MASK))
 		return 1;
 
 	/* set GO bit to initiate voltage transition */

include/power/tps65218.h

@@ -56,6 +56,8 @@ enum {
 
 #define TPS65218_MASK_ALL_BITS			0xFF
 
+#define TPS65218_DCDC_VSEL_MASK			0x3F
+
 #define TPS65218_DCDC_VOLT_SEL_0950MV		0x0a
 #define TPS65218_DCDC_VOLT_SEL_1100MV		0x19
 #define TPS65218_DCDC_VOLT_SEL_1200MV		0x23