[PATCH RFT 1/2] regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register

[PATCH RFT 1/2] regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register

[Axel Lin]

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 -EINVAL 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..3cefc63 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 -EINVAL;
 		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

[PATCH RFT 2/2] regulator: Convert pcf50633 to get_voltage_sel

[Axel Lin]

Convert pcf50633 to get_voltage_sel and then we can remove
pcf50633_regulator_voltage_value function and move its implementation
to pcf50633_regulator_list_voltage.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/regulator/pcf50633-regulator.c |   65 ++++++++++++++-----------------
 1 files changed, 29 insertions(+), 36 deletions(-)

diff --git a/drivers/regulator/pcf50633-regulator.c b/drivers/regulator/pcf50633-regulator.c
index 3cefc63..5c712e5 100644
--- a/drivers/regulator/pcf50633-regulator.c
+++ b/drivers/regulator/pcf50633-regulator.c
@@ -151,23 +151,43 @@ static int pcf50633_regulator_set_voltage(struct regulator_dev *rdev,
 	return pcf50633_reg_write(pcf, regnr, volt_bits);
 }
 
-static int pcf50633_regulator_voltage_value(enum pcf50633_regulator_id id,
-						u8 bits)
+static int pcf50633_regulator_get_voltage_sel(struct regulator_dev *rdev)
 {
+	struct pcf50633 *pcf;
+	int regulator_id;
+	u8 volt_bits, regnr;
+
+	pcf = rdev_get_drvdata(rdev);
+
+	regulator_id = rdev_get_id(rdev);
+	if (regulator_id >= PCF50633_NUM_REGULATORS)
+		return -EINVAL;
+
+	regnr = pcf50633_regulator_registers[regulator_id];
+
+	volt_bits = pcf50633_reg_read(pcf, regnr);
+
+	return volt_bits;
+}
+
+static int pcf50633_regulator_list_voltage(struct regulator_dev *rdev,
+						unsigned int index)
+{
+	int regulator_id = rdev_get_id(rdev);
 	int millivolts;
 
-	switch (id) {
+	switch (regulator_id) {
 	case PCF50633_REGULATOR_AUTO:
 		/* AUTOOUT: 00000000 to 00101110 are reserved */
-		if (bits < 0x2f)
+		if (index < 0x2f)
 			return -EINVAL;
-		millivolts = auto_voltage_value(bits);
+		millivolts = auto_voltage_value(index);
 		break;
 	case PCF50633_REGULATOR_DOWN1:
-		millivolts = down_voltage_value(bits);
+		millivolts = down_voltage_value(index);
 		break;
 	case PCF50633_REGULATOR_DOWN2:
-		millivolts = down_voltage_value(bits);
+		millivolts = down_voltage_value(index);
 		break;
 	case PCF50633_REGULATOR_LDO1:
 	case PCF50633_REGULATOR_LDO2:
@@ -177,7 +197,7 @@ static int pcf50633_regulator_voltage_value(enum pcf50633_regulator_id id,
 	case PCF50633_REGULATOR_LDO6:
 	case PCF50633_REGULATOR_HCLDO:
 	case PCF50633_REGULATOR_MEMLDO:
-		millivolts = ldo_voltage_value(bits);
+		millivolts = ldo_voltage_value(index);
 		break;
 	default:
 		return -EINVAL;
@@ -186,33 +206,6 @@ static int pcf50633_regulator_voltage_value(enum pcf50633_regulator_id id,
 	return millivolts * 1000;
 }
 
-static int pcf50633_regulator_get_voltage(struct regulator_dev *rdev)
-{
-	struct pcf50633 *pcf;
-	int regulator_id;
-	u8 volt_bits, regnr;
-
-	pcf = rdev_get_drvdata(rdev);
-
-	regulator_id = rdev_get_id(rdev);
-	if (regulator_id >= PCF50633_NUM_REGULATORS)
-		return -EINVAL;
-
-	regnr = pcf50633_regulator_registers[regulator_id];
-
-	volt_bits = pcf50633_reg_read(pcf, regnr);
-
-	return pcf50633_regulator_voltage_value(regulator_id, volt_bits);
-}
-
-static int pcf50633_regulator_list_voltage(struct regulator_dev *rdev,
-						unsigned int index)
-{
-	int regulator_id = rdev_get_id(rdev);
-
-	return pcf50633_regulator_voltage_value(regulator_id, index);
-}
-
 static int pcf50633_regulator_enable(struct regulator_dev *rdev)
 {
 	struct pcf50633 *pcf = rdev_get_drvdata(rdev);
@@ -265,7 +258,7 @@ static int pcf50633_regulator_is_enabled(struct regulator_dev *rdev)
 
 static struct regulator_ops pcf50633_regulator_ops = {
 	.set_voltage = pcf50633_regulator_set_voltage,
-	.get_voltage = pcf50633_regulator_get_voltage,
+	.get_voltage_sel = pcf50633_regulator_get_voltage_sel,
 	.list_voltage = pcf50633_regulator_list_voltage,
 	.enable = pcf50633_regulator_enable,
 	.disable = pcf50633_regulator_disable,
-- 
1.7.5.4

Re: [PATCH RFT 1/2] regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register

[Lars-Peter Clausen]

On 03/16/2012 02:35 PM, Axel Lin wrote:
> 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 -EINVAL 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..3cefc63 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] = {
>[...]
>  
> @@ -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 -EINVAL;
>  		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;
> -	}

Does this make sense? Now we return -EINVAL if index is less than 0x2f

Re: [PATCH RFT 1/2] regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register

[Axel Lin]

>> --- 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] = {
>>[...]
>>
>> @@ -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 -EINVAL;
>>               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;
>> -     }
>
> Does this make sense? Now we return -EINVAL if index is less than 0x2f
>
>
I check the code and regulator core again.
I think for this case we should return 0 instead of -EINVAL.

/**
 * regulator_list_voltage - enumerate supported voltages
 * @regulator: regulator source
 * @selector: identify voltage to list
 * Context: can sleep
 *
 * Returns a voltage that can be passed to @regulator_set_voltage(),
 * zero if this selector code can't be used on this system, or a
 * negative errno.
 */

I'll send a V2 soon.
Thanks for the review.
Axel