regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register

PATCH Applied Axel Lin 3 participants 5 messages Mar 19, 2012 Voltage and current regulator framework

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Axel Lin

author

2012-03-19 02:55 UTC #0 lore raw

PATCH v3 1/2 regulator: pcf50633: Don't write to reserved bits of AUTO output voltage select register

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:
In regulator core _regulator_do_set_voltage function:

        if (rdev->desc->ops->set_voltage) {
                ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV,
                                                   &selector);

                if (rdev->desc->ops->list_voltage)
                        selector = rdev->desc->ops->list_voltage(rdev,
                                                                 selector);
                else
                        selector = -1;

The list_voltage call here takes the selector got from set_voltage callback. Thus adding 0x2f to the index in pcf50633_regulator_list_voltage looks wrong to me.

e.g.
If min_uV < 1.8V, pcf50633_regulator_set_voltage sets 0 to selector.
For this case, adding 0x2f to the index in pcf50633_regulator_list_voltage is correct. However, if min_uV == 1.8V, pcf50633_regulator_set_voltage sets 0x2f to selector. Adding 0x2f to the index in pcf50633_regulator_list_voltage in this case is wrong.

What this patch does is:
The minimal voltage setting for AUTOOUT is 0x2f.
Thus for the case min_uV < 1.8, set the voltage setting to 1.8V by writting 0x2f to AUTOOUT register and set selector = 0x2f.
So we don't write the rserved range to AUTOOUT register.
Which means the possible range of AUTOOUT register value is 0x2f ~ 0xff.

We have no problem in regulator_get_voltage.
Since we won't write 0~0x2e to AUTOOUT register, we have no problem converting the bits we read to voltage. The equation in auto_voltage_value works fine.

For list_voltage, we need to take into account the case selector is 0 ~ 0x2e because the regulator core assumes the selector is starting from 0. This patch returns 0 for the cases selector is 0 ~ 0x2e, which means "this selector code can't be used on this system".

The regulator core iterates from 0 to n_voltages to find the small voltage in the specific range. The n_voltages settings for AUTOOUT should be 128 now, including the reserved range of AUTOOUT.

Signed-off-by Axel Lin <[email protected]>

---
 drivers/regulator/pcf50633-regulator.c |   22 ++++++----------------
 1 files changed, 6 insertions(+), 16 deletions(-)

drivers/regulator/pcf50633-regulator.c +6 ~~-16~~

index 6db46c6..c05b5d1 100644
@@ -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;

@@ -87,6 +87,9 @@ static u8 ldo_voltage_bits(unsigned int millivolts)
 /* Obtain voltage value from bits */
 static unsigned int auto_voltage_value(u8 bits)
 {
+	/* AUTOOUT: 00000000 to 00101110 are reserved.
+	 * Return 0 for bits in reserved range, which means this selector code
+	 * can't be used on this system */
 	if (bits < 0x2f)
 		return 0;

@@ -208,20 +211,7 @@ 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);
 }

@@ -287,7 +277,7 @@ static struct regulator_ops pcf50633_regulator_ops = {
 
 static struct regulator_desc regulators[] = {
 	[PCF50633_REGULATOR_AUTO] =
-		PCF50633_REGULATOR("auto", PCF50633_REGULATOR_AUTO, 81),
+		PCF50633_REGULATOR("auto", PCF50633_REGULATOR_AUTO, 128),
 	[PCF50633_REGULATOR_DOWN1] =
 		PCF50633_REGULATOR("down1", PCF50633_REGULATOR_DOWN1, 96),
 	[PCF50633_REGULATOR_DOWN2] =

Signature · 1 line

1.7.5.4

Axel Lin

author

2012-03-19 02:57 UTC #1 lore raw

PATCH v3 2/2 regulator: Convert pcf50633 to get_voltage_sel

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 <[email protected]>

---
 drivers/regulator/pcf50633-regulator.c |   62 ++++++++++++++------------------
 1 files changed, 27 insertions(+), 35 deletions(-)

drivers/regulator/pcf50633-regulator.c +27 ~~-35~~

index c05b5d1..b62f4c8 100644
@@ -157,20 +157,39 @@ 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 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];
+
+	return pcf50633_reg_read(pcf, regnr);
+}
+
+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:
-		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:

@@ -180,7 +199,7 @@ 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;

@@ -189,33 +208,6 @@ 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);

@@ -268,7 +260,7 @@ 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,

Signature · 1 line

1.7.5.4

Lars-Peter Clausen

Acked-by on v3 2/2

2012-03-19 09:10 UTC #2 lore raw

Re: [PATCH v3 2/2] regulator: Convert pcf50633 to get_voltage_sel

Quoted 5 lines · 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 <[email protected]>

Acked-by Lars-Peter Clausen <[email protected]>

Lars-Peter Clausen

Acked-by on v3 1/2

2012-03-19 09:06 UTC #3 lore raw

In reply to Axel Lin

Quoted 56 lines · 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:
In regulator core _regulator_do_set_voltage function:
        if (rdev->desc->ops->set_voltage) {
                ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV,
                                                   &selector);

                if (rdev->desc->ops->list_voltage)
                        selector = rdev->desc->ops->list_voltage(rdev,
                                                                 selector);
                else
                        selector = -1;
The list_voltage call here takes the selector got from set_voltage callback. Thus adding 0x2f to the index in pcf50633_regulator_list_voltage looks wrong to me.
e.g.
If min_uV < 1.8V, pcf50633_regulator_set_voltage sets 0 to selector.
For this case, adding 0x2f to the index in pcf50633_regulator_list_voltage is correct. However, if min_uV == 1.8V, pcf50633_regulator_set_voltage sets 0x2f to selector. Adding 0x2f to the index in pcf50633_regulator_list_voltage in this case is wrong.
What this patch does is:
The minimal voltage setting for AUTOOUT is 0x2f.
Thus for the case min_uV < 1.8, set the voltage setting to 1.8V by writting 0x2f to AUTOOUT register and set selector = 0x2f.
So we don't write the rserved range to AUTOOUT register.
Which means the possible range of AUTOOUT register value is 0x2f ~ 0xff.
We have no problem in regulator_get_voltage.
Since we won't write 0~0x2e to AUTOOUT register, we have no problem converting the bits we read to voltage. The equation in auto_voltage_value works fine.
For list_voltage, we need to take into account the case selector is 0 ~ 0x2e because the regulator core assumes the selector is starting from 0. This patch returns 0 for the cases selector is 0 ~ 0x2e, which means "this selector code can't be used on this system".

Quoted 5 lines

The regulator core iterates from 0 to n_voltages to find the small voltage in the specific range. The n_voltages settings for AUTOOUT should be 128 now, including the reserved range of AUTOOUT.
Signed-off-by Axel Lin <[email protected]>

Acked-by Lars-Peter Clausen <[email protected]>

Mark Brown

Applied

2012-03-19 14:23 UTC #4 lore raw

In reply to Axel Lin

Quoted 3 lines · 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).

Applied both, thanks.