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Subject[PATCH v2 1/2] regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register
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The datasheet says 00000000 to 00101110 are reserved, and the min value of the
voltage setting is 1.8 V.
Thus don't write 0 to AUTO output voltage select register (address 1Ah).
Table 50. AUTOOUT - AUTO output voltage select register (address 1Ah) bit description[1]
Bit Symbol Access Description
7:0 auto_out R/W VO(prog) = 0.625 + auto_out × 0.025 V
eg. 00000000 to 00101110: reserved
00101111: 1.8 V (min)
01010011: 2.7 V
01101010: 3.275 V
01101011: 3.300 V
01101100: 3.325 V
01111111 : 3.800 V (max)
..... .....
11111110 : 3.800 V
11111111 : 3.800 V
This patch also fixes a bug in pcf50633_regulator_list_voltage.
It is wrong to do "index += 0x2f" for PCF50633_REGULATOR_AUTO in
pcf50633_regulator_list_voltage. The purpose of adding 0x2f to index is because
current code return 0 in auto_voltage_bits when millivolts < 1800.
For millivolts > 1800, adding 0x2f to index is wrong.
We should handle this by
return 0 if the selector is in the reserved range of AUTOOUT.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
drivers/regulator/pcf50633-regulator.c | 23 +++++------------------
1 files changed, 5 insertions(+), 18 deletions(-)
diff --git a/drivers/regulator/pcf50633-regulator.c b/drivers/regulator/pcf50633-regulator.c
index 6db46c6..9ef7dff 100644
--- a/drivers/regulator/pcf50633-regulator.c
+++ b/drivers/regulator/pcf50633-regulator.c
@@ -52,7 +52,7 @@ static const u8 pcf50633_regulator_registers[PCF50633_NUM_REGULATORS] = {
static u8 auto_voltage_bits(unsigned int millivolts)
{
if (millivolts < 1800)
- return 0;
+ return 0x2f;
if (millivolts > 3800)
return 0xff;

@@ -87,9 +87,6 @@ static u8 ldo_voltage_bits(unsigned int millivolts)
/* Obtain voltage value from bits */
static unsigned int auto_voltage_value(u8 bits)
{
- if (bits < 0x2f)
- return 0;
-
return 625 + (bits * 25);
}

@@ -161,6 +158,9 @@ static int pcf50633_regulator_voltage_value(enum pcf50633_regulator_id id,

switch (id) {
case PCF50633_REGULATOR_AUTO:
+ /* AUTOOUT: 00000000 to 00101110 are reserved */
+ if (bits < 0x2f)
+ return 0;
millivolts = auto_voltage_value(bits);
break;
case PCF50633_REGULATOR_DOWN1:
@@ -208,20 +208,7 @@ static int pcf50633_regulator_get_voltage(struct regulator_dev *rdev)
static int pcf50633_regulator_list_voltage(struct regulator_dev *rdev,
unsigned int index)
{
- struct pcf50633 *pcf;
- int regulator_id;
-
- pcf = rdev_get_drvdata(rdev);
-
- regulator_id = rdev_get_id(rdev);
-
- switch (regulator_id) {
- case PCF50633_REGULATOR_AUTO:
- index += 0x2f;
- break;
- default:
- break;
- }
+ int regulator_id = rdev_get_id(rdev);

return pcf50633_regulator_voltage_value(regulator_id, index);
}
--
1.7.5.4


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