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    Subject[RFT][PATCH 1/2] regulator: tps80031: Fix LDO2 track mode for TPS80031 or TPS80032-ES1.0
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    Currently we have a special code in tps80031_ldo_set_voltage_sel() to handle
    LDO2 track mode for TPS80031 or TPS80032-ES1.0. The purpose is to address below
    issues:

    Issue description:
    - LDO2 traking mode is enabled
    - LDO2 tracks SMPS2 voltage.
    - LDO2 automatically switch-off when LDO2_CFG_VOLTAGE is changed to some discrete values (non exhaustive list):
    00011001, 00011010, 00011011, 00011100, .
    - LDO2 switch-on again when LDO2_CFG_VOLTAGE is changed to other values (non exhaustive list):
    00011000, 00010111, .

    LDOs have reserved codes. For these codes, LDO is switch-off.

    In tracking, LDO2 ref comes from SMPS2.
    However LDO2 enable is still gated by LDO2 VSEL decoding.
    As a result, in tracking mode LDO2 will be disabled for following code (SMPS VSEL format):
    000000 & 100000 (MSB not decoded)
    011001 & 111001 (MSB not decoded)
    011010 & 111010 (MSB not decoded)
    011100 & 111100 (MSB not decoded)
    011101 & 111101 (MSB not decoded)
    011110 & 111110 (MSB not decoded)

    However, current code has below bugs:
    1. It uses regulator_list_voltage_linear, so list_voltage() still shows above
    invalid selectors have supported voltage.
    2. Current code may return -EINVAL in tps80031_ldo_set_voltage_sel() for
    supported voltage. This is because when we use regulator_list_voltage_linear
    as list_voltage callback, regulator core will default use
    regulator_map_voltage_linear(). regulator_map_voltage_linear() has an
    assumption that the voltages are linear which is not true for this case.

    For example,
    when request voltage range is: min_uV=950000 uV && max_uV=1200000 uV
    regulator_map_voltage_linear() returns the selector is 29 (0x1D),
    set_voltage_sel() returns -EINVAL.
    (The selector is in invalid range, 0x19 ~ 0x1f).

    In above case, map_voltage() should find the lowest valid voltage within
    specific range (selector = 0x20) and set_voltage_sel() should successfully
    set the voltage to 987500 uV.

    This patch fixes these issues by:
    1. Add checking valid setting for LDO2 track mode of TPS80031 or TPS80032-ES1.0
    in list_voltage. So it returns -EINVAL for invalid selectors.
    2. Implement tps80031_ldo_map_voltage, use regulator_map_voltage_iterate()
    to find the lowest voltage within specific range for TPS80031 or
    TPS80032-ES1.0. This is required when the voltage map is no longer linear.

    Signed-off-by: Axel Lin <axel.lin@ingics.com>
    ---
    Hi Laxman,
    I don't have this hardware, can you test this patch serial?

    Thank you,
    Axel
    drivers/regulator/tps80031-regulator.c | 38 ++++++++++++++++++++++++++++----
    1 file changed, 34 insertions(+), 4 deletions(-)

    diff --git a/drivers/regulator/tps80031-regulator.c b/drivers/regulator/tps80031-regulator.c
    index 9019d0e..6430789 100644
    --- a/drivers/regulator/tps80031-regulator.c
    +++ b/drivers/regulator/tps80031-regulator.c
    @@ -238,12 +238,11 @@ static int tps80031_dcdc_get_voltage_sel(struct regulator_dev *rdev)
    return vsel & SMPS_VSEL_MASK;
    }

    -static int tps80031_ldo_set_voltage_sel(struct regulator_dev *rdev,
    - unsigned sel)
    +static int tps80031_ldo_list_voltage(struct regulator_dev *rdev,
    + unsigned int sel)
    {
    struct tps80031_regulator *ri = rdev_get_drvdata(rdev);
    struct device *parent = to_tps80031_dev(rdev);
    - int ret;

    /* Check for valid setting for TPS80031 or TPS80032-ES1.0 */
    if ((ri->rinfo->desc.id == TPS80031_REGULATOR_LDO2) &&
    @@ -260,6 +259,36 @@ static int tps80031_ldo_set_voltage_sel(struct regulator_dev *rdev,
    }
    }

    + return regulator_list_voltage_linear(rdev, sel);
    +}
    +
    +static int tps80031_ldo_map_voltage(struct regulator_dev *rdev,
    + int min_uV, int max_uV)
    +{
    + struct tps80031_regulator *ri = rdev_get_drvdata(rdev);
    + struct device *parent = to_tps80031_dev(rdev);
    +
    + /* Check for valid setting for TPS80031 or TPS80032-ES1.0 */
    + if ((ri->rinfo->desc.id == TPS80031_REGULATOR_LDO2) &&
    + (ri->device_flags & TRACK_MODE_ENABLE)) {
    + if (((tps80031_get_chip_info(parent) == TPS80031) ||
    + ((tps80031_get_chip_info(parent) == TPS80032) &&
    + (tps80031_get_pmu_version(parent) == 0x0)))) {
    + return regulator_map_voltage_iterate(rdev, min_uV,
    + max_uV);
    + }
    + }
    +
    + return regulator_map_voltage_linear(rdev, min_uV, max_uV);
    +}
    +
    +static int tps80031_ldo_set_voltage_sel(struct regulator_dev *rdev,
    + unsigned sel)
    +{
    + struct tps80031_regulator *ri = rdev_get_drvdata(rdev);
    + struct device *parent = to_tps80031_dev(rdev);
    + int ret;
    +
    ret = tps80031_write(parent, ri->rinfo->volt_id,
    ri->rinfo->volt_reg, sel);
    if (ret < 0)
    @@ -390,7 +419,8 @@ static struct regulator_ops tps80031_dcdc_ops = {
    };

    static struct regulator_ops tps80031_ldo_ops = {
    - .list_voltage = regulator_list_voltage_linear,
    + .list_voltage = tps80031_ldo_list_voltage,
    + .map_voltage = tps80031_ldo_map_voltage,
    .set_voltage_sel = tps80031_ldo_set_voltage_sel,
    .get_voltage_sel = tps80031_ldo_get_voltage_sel,
    .enable = tps80031_reg_enable,
    --
    1.7.10.4




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