Re: [PATCH v2 1/2] regulator: anatop: Add power gating support to digital LDOs

[Philipp Zabel]

Am Montag, den 10.02.2014, 15:34 +0100 schrieb Philipp Zabel:
> The ARM, PU, and SOC LDOs in the i.MX6 PMU can completely gate
> their power output. Since power gating is configured by writing
> zero to the voltage target bitfield,, store a copy of the
> voltage selector to be restored when reenabling the regulator.
> 
> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> ---
> Changes since v1:
>  - Added separate regulator_ops for core regulators that can be gated.
>  - Fixed core set_voltage_sel to not enable the regulator whenever a new
>    voltage is selected and get_voltage_sel to return the selected value.
> ---
>  drivers/regulator/anatop-regulator.c | 76 +++++++++++++++++++++++++++++++++++-
>  1 file changed, 74 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/regulator/anatop-regulator.c b/drivers/regulator/anatop-regulator.c
> index 862e63e..0c6981b 100644
> --- a/drivers/regulator/anatop-regulator.c
> +++ b/drivers/regulator/anatop-regulator.c
> @@ -34,6 +34,8 @@
>  #define LDO_RAMP_UP_UNIT_IN_CYCLES      64 /* 64 cycles per step */
>  #define LDO_RAMP_UP_FREQ_IN_MHZ         24 /* cycle based on 24M OSC */
>  
> +#define LDO_POWER_GATE			0x00
> +
>  struct anatop_regulator {
>  	const char *name;
>  	u32 control_reg;
> @@ -48,6 +50,7 @@ struct anatop_regulator {
>  	int max_voltage;
>  	struct regulator_desc rdesc;
>  	struct regulator_init_data *initdata;
> +	int sel;
>  };
>  
>  static int anatop_regmap_set_voltage_sel(struct regulator_dev *reg,
> @@ -97,14 +100,68 @@ static int anatop_regmap_get_voltage_sel(struct regulator_dev *reg)
>  	return regulator_get_voltage_sel_regmap(reg);
>  }
>  
> +static int anatop_regmap_enable(struct regulator_dev *reg)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
> +
> +	return regulator_set_voltage_sel_regmap(reg, anatop_reg->sel);
> +}
> +
> +static int anatop_regmap_disable(struct regulator_dev *reg)
> +{
> +	return regulator_set_voltage_sel_regmap(reg, LDO_POWER_GATE);
> +}
> +
> +static int anatop_regmap_is_enabled(struct regulator_dev *reg)
> +{
> +	return regulator_get_voltage_sel_regmap(reg) != LDO_POWER_GATE;
> +}
> +
> +static int anatop_regmap_core_set_voltage_sel(struct regulator_dev *reg,
> +					      unsigned selector)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
> +	int ret;
> +
> +	if (!anatop_regmap_is_enabled(reg)) {
> +		anatop_reg->sel = selector;
> +		return 0;
> +	}
> +
> +	ret = regulator_set_voltage_sel_regmap(reg, selector);
> +	if (!ret)
> +		anatop_reg->sel = selector;
> +	return ret;
> +}
> +
> +static int anatop_regmap_core_get_voltage_sel(struct regulator_dev *reg)
> +{
> +	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
> +
> +	if (!anatop_regmap_is_enabled(reg))
> +		return anatop_reg->sel;
> +
> +	return regulator_get_voltage_sel_regmap(reg);
> +}
> +
>  static struct regulator_ops anatop_rops = {
>  	.set_voltage_sel = anatop_regmap_set_voltage_sel,
> -	.set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
>  	.get_voltage_sel = anatop_regmap_get_voltage_sel,
>  	.list_voltage = regulator_list_voltage_linear,
>  	.map_voltage = regulator_map_voltage_linear,
>  };
>  
> +static struct regulator_ops anatop_core_rops = {
> +	.enable = anatop_regmap_enable,
> +	.disable = anatop_regmap_disable,
> +	.is_enabled = anatop_regmap_is_enabled,
> +	.set_voltage_sel = anatop_regmap_core_set_voltage_sel,
> +	.set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
> +	.get_voltage_sel = anatop_regmap_core_get_voltage_sel,
> +	.list_voltage = regulator_list_voltage_linear,
> +	.map_voltage = regulator_map_voltage_linear,
> +};
> +
>  static int anatop_regulator_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -116,6 +173,7 @@ static int anatop_regulator_probe(struct platform_device *pdev)
>  	struct regulator_init_data *initdata;
>  	struct regulator_config config = { };
>  	int ret = 0;
> +	u32 val;
>  
>  	initdata = of_get_regulator_init_data(dev, np);
>  	sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
> @@ -125,7 +183,6 @@ static int anatop_regulator_probe(struct platform_device *pdev)
>  	sreg->name = of_get_property(np, "regulator-name", NULL);
>  	rdesc = &sreg->rdesc;
>  	rdesc->name = sreg->name;
> -	rdesc->ops = &anatop_rops;
>  	rdesc->type = REGULATOR_VOLTAGE;
>  	rdesc->owner = THIS_MODULE;
>  
> @@ -197,6 +254,21 @@ static int anatop_regulator_probe(struct platform_device *pdev)
>  	config.of_node = pdev->dev.of_node;
>  	config.regmap = sreg->anatop;
>  
> +	/* Only core regulators have the ramp up delay configuration. */
> +	if (sreg->control_reg && sreg->delay_bit_width) {
> +		rdesc->ops = &anatop_core_rops;
> +
> +		ret = regmap_read(config.regmap, rdesc->vsel_reg, &val);
> +		if (ret) {
> +			dev_err(dev, "failed to read initial state\n");
> +			goto anatop_probe_end;

Sorry, this doesn't exist anymore in v3.14-rc1. I'll replace it with
"return ret;" for v3.

> +		}
> +
> +		sreg->sel = (val & rdesc->vsel_mask) >> sreg->vol_bit_shift;
> +	} else {
> +		rdesc->ops = &anatop_rops;
> +	}
> +
>  	/* register regulator */
>  	rdev = devm_regulator_register(dev, rdesc, &config);
>  	if (IS_ERR(rdev)) {

regards
Philipp

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