regulator: palmas: preserve modes of rails during enable/disable
authorLaxman Dewangan <ldewangan@nvidia.com>
Thu, 18 Apr 2013 13:02:48 +0000 (18:32 +0530)
committerMark Brown <broonie@opensource.wolfsonmicro.com>
Thu, 18 Apr 2013 17:23:53 +0000 (18:23 +0100)
The Palma device like TPS65913 have the mode mask which is also
used for enable/disable the rails. The mode bits are defined as
00: OFF
01: AUTO
10: ECO
11: Forced PWM

and modes are set accordingly as
REGULATOR_MODE_NORMAL: AUTO
REGULATOR_MODE_IDLE: ECO
REGULATOR_MODE_FAST: PWM

Two issue observed:
1. If client calls following sequence:
regulator_enable(),
regulator_set_mode(FAST),
regulator_disable()

and again the regulator_enable() then the mode is reset
to NORMAL inplace of keeping the mode as FAST.

Fixing this by storing the current mode configured by client
and restoring modes when enable() is called after disable().

2. In following sequence, the regulator get enabled:
regulator_disable()
regulator_set_mode(FAST),

Fixing this by updating new mode in register only if it is
enabled.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
drivers/regulator/palmas-regulator.c
include/linux/mfd/palmas.h

index 3336916..38447ac 100644 (file)
@@ -274,7 +274,10 @@ static int palmas_enable_smps(struct regulator_dev *dev)
        palmas_smps_read(pmic->palmas, palmas_regs_info[id].ctrl_addr, &reg);
 
        reg &= ~PALMAS_SMPS12_CTRL_MODE_ACTIVE_MASK;
-       reg |= SMPS_CTRL_MODE_ON;
+       if (pmic->current_reg_mode[id])
+               reg |= pmic->current_reg_mode[id];
+       else
+               reg |= SMPS_CTRL_MODE_ON;
 
        palmas_smps_write(pmic->palmas, palmas_regs_info[id].ctrl_addr, reg);
 
@@ -296,16 +299,19 @@ static int palmas_disable_smps(struct regulator_dev *dev)
        return 0;
 }
 
-
 static int palmas_set_mode_smps(struct regulator_dev *dev, unsigned int mode)
 {
        struct palmas_pmic *pmic = rdev_get_drvdata(dev);
        int id = rdev_get_id(dev);
        unsigned int reg;
+       bool rail_enable = true;
 
        palmas_smps_read(pmic->palmas, palmas_regs_info[id].ctrl_addr, &reg);
        reg &= ~PALMAS_SMPS12_CTRL_MODE_ACTIVE_MASK;
 
+       if (reg == SMPS_CTRL_MODE_OFF)
+               rail_enable = false;
+
        switch (mode) {
        case REGULATOR_MODE_NORMAL:
                reg |= SMPS_CTRL_MODE_ON;
@@ -319,8 +325,11 @@ static int palmas_set_mode_smps(struct regulator_dev *dev, unsigned int mode)
        default:
                return -EINVAL;
        }
-       palmas_smps_write(pmic->palmas, palmas_regs_info[id].ctrl_addr, reg);
 
+       pmic->current_reg_mode[id] = reg & PALMAS_SMPS12_CTRL_MODE_ACTIVE_MASK;
+       if (rail_enable)
+               palmas_smps_write(pmic->palmas,
+                       palmas_regs_info[id].ctrl_addr, reg);
        return 0;
 }
 
@@ -330,9 +339,7 @@ static unsigned int palmas_get_mode_smps(struct regulator_dev *dev)
        int id = rdev_get_id(dev);
        unsigned int reg;
 
-       palmas_smps_read(pmic->palmas, palmas_regs_info[id].ctrl_addr, &reg);
-       reg &= PALMAS_SMPS12_CTRL_STATUS_MASK;
-       reg >>= PALMAS_SMPS12_CTRL_STATUS_SHIFT;
+       reg = pmic->current_reg_mode[id] & PALMAS_SMPS12_CTRL_MODE_ACTIVE_MASK;
 
        switch (reg) {
        case SMPS_CTRL_MODE_ON:
@@ -871,7 +878,8 @@ static int palmas_regulators_probe(struct platform_device *pdev)
                        /*
                         * Read and store the RANGE bit for later use
                         * This must be done before regulator is probed,
-                        * otherwise we error in probe with unsupportable ranges.
+                        * otherwise we error in probe with unsupportable
+                        * ranges. Read the current smps mode for later use.
                         */
                        addr = palmas_regs_info[id].vsel_addr;
 
@@ -888,6 +896,14 @@ static int palmas_regulators_probe(struct platform_device *pdev)
                                                palmas_regs_info[id].vsel_addr);
                        pmic->desc[id].vsel_mask =
                                        PALMAS_SMPS12_VOLTAGE_VSEL_MASK;
+
+                       /* Read the smps mode for later use. */
+                       addr = palmas_regs_info[id].ctrl_addr;
+                       ret = palmas_smps_read(pmic->palmas, addr, &reg);
+                       if (ret)
+                               goto err_unregister_regulator;
+                       pmic->current_reg_mode[id] = reg &
+                                       PALMAS_SMPS12_CTRL_MODE_ACTIVE_MASK;
                }
 
                pmic->desc[id].type = REGULATOR_VOLTAGE;
index a58c579..e971a7c 100644 (file)
@@ -327,6 +327,7 @@ struct palmas_pmic {
 
        int range[PALMAS_REG_SMPS10];
        unsigned int ramp_delay[PALMAS_REG_SMPS10];
+       unsigned int current_reg_mode[PALMAS_REG_SMPS10];
 };
 
 struct palmas_resource {