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Message-ID: <d763c1b4-93dc-46a5-8e46-2e4ede67875a@nexus-software.ie>
Date: Wed, 8 May 2024 18:55:44 +0100
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Subject: Re: [PATCH 12/13] regulator: add pm8008 pmic regulator driver
To: Johan Hovold <johan+linaro@kernel.org>, Lee Jones <lee@kernel.org>,
 Mark Brown <broonie@kernel.org>, Linus Walleij <linus.walleij@linaro.org>,
 Bjorn Andersson <andersson@kernel.org>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>, Rob Herring <robh@kernel.org>,
 Krzysztof Kozlowski <krzk+dt@kernel.org>, Conor Dooley
 <conor+dt@kernel.org>, Liam Girdwood <lgirdwood@gmail.com>,
 Das Srinagesh <quic_gurus@quicinc.com>,
 Satya Priya <quic_c_skakit@quicinc.com>, Stephen Boyd <swboyd@chromium.org>,
 linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org
References: <20240506150830.23709-1-johan+linaro@kernel.org>
 <20240506150830.23709-13-johan+linaro@kernel.org>
Content-Language: en-US
From: Bryan O'Donoghue <pure.logic@nexus-software.ie>
In-Reply-To: <20240506150830.23709-13-johan+linaro@kernel.org>
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On 06/05/2024 16:08, Johan Hovold wrote:
> From: Satya Priya <quic_c_skakit@quicinc.com>
> 
> Qualcomm Technologies, Inc. PM8008 is an I2C-controlled PMIC containing
> seven LDO regulators. Add a PM8008 regulator driver to support PMIC
> regulator management via the regulator framework.
> 
> Note that this driver, originally submitted by Satya Priya [1], has been
> reworked to match the new devicetree binding which no longer describes
> each regulator as a separate device.
> 
> This avoids describing internal details like register offsets in the
> devicetree and allows for extending the implementation with features
> like over-current protection without having to update the binding.
> 
> Specifically note that the regulator interrupts are shared between all
> regulators.
> 
> Note that the secondary regmap is looked up by name and that if the
> driver ever needs to be generalised to support regulators provided by
> the primary regmap (I2C address) such information could be added to a
> driver lookup table matching on the parent compatible.
> 
> This also fixes the original implementation, which looked up regulators
> by 'regulator-name' property rather than devicetree node name and which
> prevented the regulators from being named to match board schematics.
> 
> [1] https://lore.kernel.org/r/1655200111-18357-8-git-send-email-quic_c_skakit@quicinc.com
> 
> Signed-off-by: Satya Priya <quic_c_skakit@quicinc.com>
> Cc: Stephen Boyd <swboyd@chromium.org>
> [ johan: rework probe to match new binding, amend commit message and
>           Kconfig entry]
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>   drivers/regulator/Kconfig                 |   7 +
>   drivers/regulator/Makefile                |   1 +
>   drivers/regulator/qcom-pm8008-regulator.c | 215 ++++++++++++++++++++++
>   3 files changed, 223 insertions(+)
>   create mode 100644 drivers/regulator/qcom-pm8008-regulator.c
> 
> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
> index 7db0a29b5b8d..d07d034ef1a2 100644
> --- a/drivers/regulator/Kconfig
> +++ b/drivers/regulator/Kconfig
> @@ -1027,6 +1027,13 @@ config REGULATOR_PWM
>   	  This driver supports PWM controlled voltage regulators. PWM
>   	  duty cycle can increase or decrease the voltage.
>   
> +config REGULATOR_QCOM_PM8008
> +	tristate "Qualcomm Technologies, Inc. PM8008 PMIC regulators"
> +	depends on MFD_QCOM_PM8008
> +	help
> +	  Select this option to enable support for the voltage regulators in
> +	  Qualcomm Technologies, Inc. PM8008 PMICs.
> +
>   config REGULATOR_QCOM_REFGEN
>   	tristate "Qualcomm REFGEN regulator driver"
>   	depends on ARCH_QCOM || COMPILE_TEST
> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
> index 46fb569e6be8..0457b0925b3e 100644
> --- a/drivers/regulator/Makefile
> +++ b/drivers/regulator/Makefile
> @@ -112,6 +112,7 @@ obj-$(CONFIG_REGULATOR_MT6380)	+= mt6380-regulator.o
>   obj-$(CONFIG_REGULATOR_MT6397)	+= mt6397-regulator.o
>   obj-$(CONFIG_REGULATOR_MTK_DVFSRC) += mtk-dvfsrc-regulator.o
>   obj-$(CONFIG_REGULATOR_QCOM_LABIBB) += qcom-labibb-regulator.o
> +obj-$(CONFIG_REGULATOR_QCOM_PM8008) += qcom-pm8008-regulator.o
>   obj-$(CONFIG_REGULATOR_QCOM_REFGEN) += qcom-refgen-regulator.o
>   obj-$(CONFIG_REGULATOR_QCOM_RPM) += qcom_rpm-regulator.o
>   obj-$(CONFIG_REGULATOR_QCOM_RPMH) += qcom-rpmh-regulator.o
> diff --git a/drivers/regulator/qcom-pm8008-regulator.c b/drivers/regulator/qcom-pm8008-regulator.c
> new file mode 100644
> index 000000000000..51f1ce5e043c
> --- /dev/null
> +++ b/drivers/regulator/qcom-pm8008-regulator.c
> @@ -0,0 +1,215 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/driver.h>
> +
> +#define VSET_STEP_MV			8
> +#define VSET_STEP_UV			(VSET_STEP_MV * 1000)
> +
> +#define LDO_ENABLE_REG(base)		((base) + 0x46)
> +#define ENABLE_BIT			BIT(7)
> +
> +#define LDO_VSET_LB_REG(base)		((base) + 0x40)
> +
> +#define LDO_STEPPER_CTL_REG(base)	((base) + 0x3b)
> +#define DEFAULT_VOLTAGE_STEPPER_RATE	38400
> +#define STEP_RATE_MASK			GENMASK(1, 0)
> +
> +#define NLDO_MIN_UV			528000
> +#define NLDO_MAX_UV			1504000
> +
> +#define PLDO_MIN_UV			1504000
> +#define PLDO_MAX_UV			3400000
> +
> +struct pm8008_regulator_data {
> +	const char			*name;
> +	const char			*supply_name;
> +	u16				base;
> +	int				min_dropout_uv;
> +	const struct linear_range	*voltage_range;
> +};
> +
> +struct pm8008_regulator {
> +	struct regmap		*regmap;
> +	struct regulator_desc	rdesc;
> +	u16			base;
> +	int			step_rate;
> +};
> +
> +static const struct linear_range nldo_ranges[] = {
> +	REGULATOR_LINEAR_RANGE(528000, 0, 122, 8000),
> +};
> +
> +static const struct linear_range pldo_ranges[] = {
> +	REGULATOR_LINEAR_RANGE(1504000, 0, 237, 8000),
> +};
> +
> +static const struct pm8008_regulator_data reg_data[] = {
> +	/* name	  parent       base    headroom_uv voltage_range */
> +	{ "ldo1", "vdd_l1_l2", 0x4000, 225000, nldo_ranges, },
> +	{ "ldo2", "vdd_l1_l2", 0x4100, 225000, nldo_ranges, },
> +	{ "ldo3", "vdd_l3_l4", 0x4200, 300000, pldo_ranges, },
> +	{ "ldo4", "vdd_l3_l4", 0x4300, 300000, pldo_ranges, },
> +	{ "ldo5", "vdd_l5",    0x4400, 200000, pldo_ranges, },
> +	{ "ldo6", "vdd_l6",    0x4500, 200000, pldo_ranges, },
> +	{ "ldo7", "vdd_l7",    0x4600, 200000, pldo_ranges, },
> +};
> +
> +static int pm8008_regulator_get_voltage(struct regulator_dev *rdev)
> +{
> +	struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev);
> +	__le16 mV;
> +	int uV;
> +
> +	regmap_bulk_read(pm8008_reg->regmap,
> +			LDO_VSET_LB_REG(pm8008_reg->base), (void *)&mV, 2);
> +
> +	uV = le16_to_cpu(mV) * 1000;
> +	return (uV - pm8008_reg->rdesc.min_uV) / pm8008_reg->rdesc.uV_step;
> +}
> +
> +static inline int pm8008_write_voltage(struct pm8008_regulator *pm8008_reg,
> +							int mV)
> +{
> +	__le16 vset_raw;
> +
> +	vset_raw = cpu_to_le16(mV);
> +
> +	return regmap_bulk_write(pm8008_reg->regmap,
> +			LDO_VSET_LB_REG(pm8008_reg->base),
> +			(const void *)&vset_raw, sizeof(vset_raw));
> +}
> +
> +static int pm8008_regulator_set_voltage_time(struct regulator_dev *rdev,
> +				int old_uV, int new_uv)
> +{
> +	struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev);
> +
> +	return DIV_ROUND_UP(abs(new_uv - old_uV), pm8008_reg->step_rate);
> +}
> +
> +static int pm8008_regulator_set_voltage(struct regulator_dev *rdev,
> +					unsigned int selector)
> +{
> +	struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev);
> +	int rc, mV;
> +
> +	rc = regulator_list_voltage_linear_range(rdev, selector);
> +	if (rc < 0)
> +		return rc;
> +
> +	/* voltage control register is set with voltage in millivolts */
> +	mV = DIV_ROUND_UP(rc, 1000);
> +
> +	rc = pm8008_write_voltage(pm8008_reg, mV);
> +	if (rc < 0)
> +		return rc;
> +
> +	return 0;
> +}
> +
> +static const struct regulator_ops pm8008_regulator_ops = {
> +	.enable			= regulator_enable_regmap,
> +	.disable		= regulator_disable_regmap,
> +	.is_enabled		= regulator_is_enabled_regmap,
> +	.set_voltage_sel	= pm8008_regulator_set_voltage,
> +	.get_voltage_sel	= pm8008_regulator_get_voltage,
> +	.list_voltage		= regulator_list_voltage_linear,
> +	.set_voltage_time	= pm8008_regulator_set_voltage_time,
> +};
> +
> +static int pm8008_regulator_probe(struct platform_device *pdev)
> +{
> +	struct regulator_config reg_config = {};
> +	struct pm8008_regulator *pm8008_reg;
> +	struct device *dev = &pdev->dev;
> +	struct regulator_desc *rdesc;
> +	struct regulator_dev *rdev;
> +	struct regmap *regmap;
> +	unsigned int val;
> +	int rc, i;
> +
> +	regmap = dev_get_regmap(dev->parent, "secondary");
> +	if (!regmap)
> +		return -EINVAL;
> +
> +	for (i = 0; i < ARRAY_SIZE(reg_data); i++) {
> +		pm8008_reg = devm_kzalloc(dev, sizeof(*pm8008_reg), GFP_KERNEL);
> +		if (!pm8008_reg)
> +			return -ENOMEM;
> +
> +		pm8008_reg->regmap = regmap;
> +		pm8008_reg->base = reg_data[i].base;
> +
> +		/* get slew rate */
> +		rc = regmap_bulk_read(pm8008_reg->regmap,
> +				LDO_STEPPER_CTL_REG(pm8008_reg->base), &val, 1);
> +		if (rc < 0) {
> +			dev_err(dev, "failed to read step rate: %d\n", rc);
> +			return rc;
> +		}
> +		val &= STEP_RATE_MASK;
> +		pm8008_reg->step_rate = DEFAULT_VOLTAGE_STEPPER_RATE >> val;
> +
> +		rdesc = &pm8008_reg->rdesc;
> +		rdesc->type = REGULATOR_VOLTAGE;
> +		rdesc->ops = &pm8008_regulator_ops;
> +		rdesc->name = reg_data[i].name;
> +		rdesc->supply_name = reg_data[i].supply_name;
> +		rdesc->of_match = reg_data[i].name;
> +		rdesc->uV_step = VSET_STEP_UV;
> +		rdesc->linear_ranges = reg_data[i].voltage_range;
> +		rdesc->n_linear_ranges = 1;
> +		BUILD_BUG_ON((ARRAY_SIZE(pldo_ranges) != 1) ||
> +				(ARRAY_SIZE(nldo_ranges) != 1));
> +
> +		if (reg_data[i].voltage_range == nldo_ranges) {
> +			rdesc->min_uV = NLDO_MIN_UV;
> +			rdesc->n_voltages = ((NLDO_MAX_UV - NLDO_MIN_UV) / rdesc->uV_step) + 1;
> +		} else {
> +			rdesc->min_uV = PLDO_MIN_UV;
> +			rdesc->n_voltages = ((PLDO_MAX_UV - PLDO_MIN_UV) / rdesc->uV_step) + 1;
> +		}
> +
> +		rdesc->enable_reg = LDO_ENABLE_REG(pm8008_reg->base);
> +		rdesc->enable_mask = ENABLE_BIT;
> +		rdesc->min_dropout_uV = reg_data[i].min_dropout_uv;
> +		rdesc->regulators_node = of_match_ptr("regulators");
> +
> +		reg_config.dev = dev->parent;
> +		reg_config.driver_data = pm8008_reg;
> +		reg_config.regmap = pm8008_reg->regmap;
> +
> +		rdev = devm_regulator_register(dev, rdesc, &reg_config);
> +		if (IS_ERR(rdev)) {
> +			rc = PTR_ERR(rdev);
> +			dev_err(dev, "failed to register regulator %s: %d\n",
> +					reg_data[i].name, rc);
> +			return rc;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static struct platform_driver pm8008_regulator_driver = {
> +	.driver	= {
> +		.name = "qcom-pm8008-regulator",
> +	},
> +	.probe = pm8008_regulator_probe,
> +};
> +
> +module_platform_driver(pm8008_regulator_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. PM8008 PMIC Regulator Driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:qcom-pm8008-regulator");

Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>