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regulator: s5m8767a: Support AP watchdog reset operation
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The S5M8767A can't know status of ap reset.
So, After AP watchdog reset, AP can't boot normally.

Problem can be happened like below condition.
- AP Bootable lowest voltage(vdd_arm): 0.9v
- AP DVFS voltage table: 0.8v, 0.9v, 1.0v
- During AP works on lowest voltage(0.8V), watchdog reset is asserted
- AP can't boot, because vdd arm is still 0.8v

Solution
- Basic concept:
  After ap watchdog reset, GPIO configuration is changed by default value
- S5M8767A has function of voltage control with gpio (8 levels with 3 gpios)
- Set bootable voltage on level 0 -> can work with default gpio configuration
- In the probing, Change voltage control level from level 0 to level 1
- Execute normal dvfs operation on level 1
- After watchdog reset, ap gpio is set by default value
- PMIC operation mode is changed by ap reset (level1 -> level0)
- Regardless of previous vdd_arm voltage, AP always can be booted.

Signed-off-by: Sangbeom Kim <sbkim73@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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Sangbeom Kim authored and Mark Brown committed Jun 19, 2012
1 parent 852abad commit c848bc8
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Showing 2 changed files with 98 additions and 44 deletions.
137 changes: 93 additions & 44 deletions drivers/regulator/s5m8767.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,7 @@ struct s5m8767_info {
u8 buck3_vol[8];
u8 buck4_vol[8];
int buck_gpios[3];
int buck_ds[3];
int buck_gpioindex;
};

Expand Down Expand Up @@ -283,17 +284,17 @@ static int s5m8767_get_voltage_register(struct regulator_dev *rdev, int *_reg)
reg = S5M8767_REG_BUCK1CTRL2;
break;
case S5M8767_BUCK2:
reg = S5M8767_REG_BUCK2DVS1;
reg = S5M8767_REG_BUCK2DVS2;
if (s5m8767->buck2_gpiodvs)
reg += s5m8767->buck_gpioindex;
break;
case S5M8767_BUCK3:
reg = S5M8767_REG_BUCK3DVS1;
reg = S5M8767_REG_BUCK3DVS2;
if (s5m8767->buck3_gpiodvs)
reg += s5m8767->buck_gpioindex;
break;
case S5M8767_BUCK4:
reg = S5M8767_REG_BUCK4DVS1;
reg = S5M8767_REG_BUCK4DVS2;
if (s5m8767->buck4_gpiodvs)
reg += s5m8767->buck_gpioindex;
break;
Expand Down Expand Up @@ -512,7 +513,7 @@ static __devinit int s5m8767_pmic_probe(struct platform_device *pdev)
struct regulator_config config = { };
struct regulator_dev **rdev;
struct s5m8767_info *s5m8767;
int i, ret, size;
int i, ret, size, buck_init;

if (!pdata) {
dev_err(pdev->dev.parent, "Platform data not supplied\n");
Expand Down Expand Up @@ -563,12 +564,37 @@ static __devinit int s5m8767_pmic_probe(struct platform_device *pdev)
s5m8767->buck_gpios[0] = pdata->buck_gpios[0];
s5m8767->buck_gpios[1] = pdata->buck_gpios[1];
s5m8767->buck_gpios[2] = pdata->buck_gpios[2];
s5m8767->buck_ds[0] = pdata->buck_ds[0];
s5m8767->buck_ds[1] = pdata->buck_ds[1];
s5m8767->buck_ds[2] = pdata->buck_ds[2];

s5m8767->ramp_delay = pdata->buck_ramp_delay;
s5m8767->buck2_ramp = pdata->buck2_ramp_enable;
s5m8767->buck3_ramp = pdata->buck3_ramp_enable;
s5m8767->buck4_ramp = pdata->buck4_ramp_enable;
s5m8767->opmode = pdata->opmode;

buck_init = s5m8767_convert_voltage_to_sel(&buck_voltage_val2,
pdata->buck2_init,
pdata->buck2_init +
buck_voltage_val2.step);

s5m_reg_write(s5m8767->iodev, S5M8767_REG_BUCK2DVS2, buck_init);

buck_init = s5m8767_convert_voltage_to_sel(&buck_voltage_val2,
pdata->buck3_init,
pdata->buck3_init +
buck_voltage_val2.step);

s5m_reg_write(s5m8767->iodev, S5M8767_REG_BUCK3DVS2, buck_init);

buck_init = s5m8767_convert_voltage_to_sel(&buck_voltage_val2,
pdata->buck4_init,
pdata->buck4_init +
buck_voltage_val2.step);

s5m_reg_write(s5m8767->iodev, S5M8767_REG_BUCK4DVS2, buck_init);

for (i = 0; i < 8; i++) {
if (s5m8767->buck2_gpiodvs) {
s5m8767->buck2_vol[i] =
Expand Down Expand Up @@ -598,48 +624,71 @@ static __devinit int s5m8767_pmic_probe(struct platform_device *pdev)
}
}

if (pdata->buck2_gpiodvs || pdata->buck3_gpiodvs ||
pdata->buck4_gpiodvs) {
if (gpio_is_valid(pdata->buck_gpios[0]) &&
gpio_is_valid(pdata->buck_gpios[1]) &&
gpio_is_valid(pdata->buck_gpios[2])) {
ret = gpio_request(pdata->buck_gpios[0],
"S5M8767 SET1");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request for SET1\n");

ret = gpio_request(pdata->buck_gpios[1],
"S5M8767 SET2");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request for SET2\n");

ret = gpio_request(pdata->buck_gpios[2],
"S5M8767 SET3");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request for SET3\n");
/* SET1 GPIO */
gpio_direction_output(pdata->buck_gpios[0],
(s5m8767->buck_gpioindex >> 2) & 0x1);
/* SET2 GPIO */
gpio_direction_output(pdata->buck_gpios[1],
(s5m8767->buck_gpioindex >> 1) & 0x1);
/* SET3 GPIO */
gpio_direction_output(pdata->buck_gpios[2],
(s5m8767->buck_gpioindex >> 0) & 0x1);
ret = 0;
} else {
dev_err(&pdev->dev, "GPIO NOT VALID\n");
ret = -EINVAL;
return ret;
}
if (gpio_is_valid(pdata->buck_gpios[0]) &&
gpio_is_valid(pdata->buck_gpios[1]) &&
gpio_is_valid(pdata->buck_gpios[2])) {
ret = gpio_request(pdata->buck_gpios[0], "S5M8767 SET1");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request"
" for SET1\n");

ret = gpio_request(pdata->buck_gpios[1], "S5M8767 SET2");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request"
" for SET2\n");

ret = gpio_request(pdata->buck_gpios[2], "S5M8767 SET3");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request"
" for SET3\n");
/* SET1 GPIO */
gpio_direction_output(pdata->buck_gpios[0],
(s5m8767->buck_gpioindex >> 2) & 0x1);
/* SET2 GPIO */
gpio_direction_output(pdata->buck_gpios[1],
(s5m8767->buck_gpioindex >> 1) & 0x1);
/* SET3 GPIO */
gpio_direction_output(pdata->buck_gpios[2],
(s5m8767->buck_gpioindex >> 0) & 0x1);
ret = 0;

} else {
dev_err(&pdev->dev, "GPIO NOT VALID\n");
ret = -EINVAL;
return ret;
}

s5m_reg_update(s5m8767->iodev, S5M8767_REG_BUCK2CTRL,
(pdata->buck2_gpiodvs) ? (1 << 1) : (0 << 1), 1 << 1);
s5m_reg_update(s5m8767->iodev, S5M8767_REG_BUCK3CTRL,
(pdata->buck3_gpiodvs) ? (1 << 1) : (0 << 1), 1 << 1);
s5m_reg_update(s5m8767->iodev, S5M8767_REG_BUCK4CTRL,
(pdata->buck4_gpiodvs) ? (1 << 1) : (0 << 1), 1 << 1);
ret = gpio_request(pdata->buck_ds[0], "S5M8767 DS2");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request for DS2\n");

ret = gpio_request(pdata->buck_ds[1], "S5M8767 DS3");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request for DS3\n");

ret = gpio_request(pdata->buck_ds[2], "S5M8767 DS4");
if (ret == -EBUSY)
dev_warn(&pdev->dev, "Duplicated gpio request for DS4\n");

/* DS2 GPIO */
gpio_direction_output(pdata->buck_ds[0], 0x0);
/* DS3 GPIO */
gpio_direction_output(pdata->buck_ds[1], 0x0);
/* DS4 GPIO */
gpio_direction_output(pdata->buck_ds[2], 0x0);

if (pdata->buck2_gpiodvs || pdata->buck3_gpiodvs ||
pdata->buck4_gpiodvs) {
s5m_reg_update(s5m8767->iodev, S5M8767_REG_BUCK2CTRL,
(pdata->buck2_gpiodvs) ? (1 << 1) : (0 << 1),
1 << 1);
s5m_reg_update(s5m8767->iodev, S5M8767_REG_BUCK3CTRL,
(pdata->buck3_gpiodvs) ? (1 << 1) : (0 << 1),
1 << 1);
s5m_reg_update(s5m8767->iodev, S5M8767_REG_BUCK4CTRL,
(pdata->buck4_gpiodvs) ? (1 << 1) : (0 << 1),
1 << 1);
}

/* Initialize GPIO DVS registers */
for (i = 0; i < 8; i++) {
Expand Down
5 changes: 5 additions & 0 deletions include/linux/mfd/s5m87xx/s5m-core.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -347,6 +347,7 @@ struct s5m_platform_data {
bool buck_voltage_lock;

int buck_gpios[3];
int buck_ds[3];
int buck2_voltage[8];
bool buck2_gpiodvs;
int buck3_voltage[8];
Expand All @@ -369,6 +370,10 @@ struct s5m_platform_data {
bool buck2_ramp_enable;
bool buck3_ramp_enable;
bool buck4_ramp_enable;

int buck2_init;
int buck3_init;
int buck4_init;
};

#endif /* __LINUX_MFD_S5M_CORE_H */

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