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Message-ID: <e8637fc1-804a-4ec5-80dd-4afa2dfd40bb@quicinc.com>
Date:   Thu, 9 Jun 2022 10:50:27 +0530
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Subject: Re: [PATCH V14 7/9] regulator: Add a regulator driver for the PM8008
 PMIC
Content-Language: en-US
To:     Stephen Boyd <swboyd@chromium.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>
CC:     Lee Jones <lee.jones@linaro.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <quic_collinsd@quicinc.com>,
        <quic_subbaram@quicinc.com>, <quic_jprakash@quicinc.com>
References: <1654602615-28849-1-git-send-email-quic_c_skakit@quicinc.com>
 <1654602615-28849-8-git-send-email-quic_c_skakit@quicinc.com>
 <CAE-0n53iZk3U3ZWHj8VBUn2gi1KzFz0ZdxABiZvTPzK=cKu1Ng@mail.gmail.com>
From:   "Satya Priya Kakitapalli (Temp)" <quic_c_skakit@quicinc.com>
In-Reply-To: <CAE-0n53iZk3U3ZWHj8VBUn2gi1KzFz0ZdxABiZvTPzK=cKu1Ng@mail.gmail.com>
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Hi Stephen,

On 6/9/2022 1:12 AM, Stephen Boyd wrote:
> Quoting Satya Priya (2022-06-07 04:50:13)
>> diff --git a/drivers/regulator/qcom-pm8008-regulator.c b/drivers/regulator/qcom-pm8008-regulator.c
>> new file mode 100644
>> index 0000000..71cb95c
>> --- /dev/null
>> +++ b/drivers/regulator/qcom-pm8008-regulator.c
>> @@ -0,0 +1,248 @@
>> +// 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/mfd/qcom_pm8008.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;
>> +       int                             min_dropout_uv;
>> +       const struct linear_range       *voltage_range;
>> +};
>> +
>> +struct pm8008_regulator {
>> +       struct device           *dev;
> Is this used anywhere?


Will remove it.


>> +       struct regmap           *regmap;
>> +       struct regulator_desc   rdesc;
>> +       u16                     base;
>> +       int                     step_rate;
>> +       int                     voltage_selector;
>> +};
>> +
>> +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_assert(ARRAY_SIZE(pldo_ranges) == 1 && ARRAY_SIZE(nldo_ranges) == 1);
> Can this static_assert be placed next to the assignment of
> n_linear_ranges in probe?
>
>> +
>> +static const struct pm8008_regulator_data reg_data[] = {
>> +       /* name  parent       headroom_uv voltage_range */
>> +       { "ldo1", "vdd_l1_l2", 225000, nldo_ranges, },
>> +       { "ldo2", "vdd_l1_l2", 225000, nldo_ranges, },
>> +       { "ldo3", "vdd_l3_l4", 300000, pldo_ranges, },
>> +       { "ldo4", "vdd_l3_l4", 300000, pldo_ranges, },
>> +       { "ldo5", "vdd_l5",    200000, pldo_ranges, },
>> +       { "ldo6", "vdd_l6",    200000, pldo_ranges, },
>> +       { "ldo7", "vdd_l7",    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 rc, 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;
>> +
>> +       pm8008_reg->voltage_selector = selector;
> Is this used anywhere? I think not so remove it and the struct member?


Okay.


>> +
>> +       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)
>> +{
>> +       int rc, i;
>> +       u32 base;
>> +       unsigned int reg;
>> +       const char *name;
>> +       struct device *dev = &pdev->dev;
>> +       struct regulator_config reg_config = {};
>> +       struct regulator_dev    *rdev;
>> +       const struct pm8008_data *chip = dev_get_drvdata(pdev->dev.parent);
>> +       struct pm8008_regulator *pm8008_reg;
>> +
>> +       pm8008_reg = devm_kzalloc(dev, sizeof(*pm8008_reg), GFP_KERNEL);
>> +       if (!pm8008_reg)
>> +               return -ENOMEM;
>> +
>> +       pm8008_reg->regmap = pm8008_get_regmap(chip);
>> +       if (!pm8008_reg->regmap) {
>> +               dev_err(dev, "parent regmap is missing\n");
>> +               return -EINVAL;
>> +       }
>> +
>> +       pm8008_reg->dev = dev;
>> +
>> +       rc = of_property_read_string(dev->of_node, "regulator-name", &name);
>> +       if (rc)
>> +               return rc;
>> +
>> +       /* get the required regulator data */
>> +       for (i = 0; i < ARRAY_SIZE(reg_data); i++)
>> +               if (strstr(name, reg_data[i].name))
>> +                       break;
>> +
>> +       if (i == ARRAY_SIZE(reg_data)) {
>> +               dev_err(dev, "Invalid regulator name %s\n", name);
>> +               return -EINVAL;
>> +       }
>> +
>> +       rc = of_property_read_u32_index(dev->of_node, "reg", 1, &base);
>> +       if (rc < 0) {
>> +               dev_err(dev, "%s: failed to get regulator base rc=%d\n", name, rc);
>> +               return rc;
>> +       }
>> +       pm8008_reg->base = base;
>> +
>> +       /* get slew rate */
>> +       rc = regmap_bulk_read(pm8008_reg->regmap,
>> +                       LDO_STEPPER_CTL_REG(pm8008_reg->base), &reg, 1);
>> +       if (rc < 0) {
>> +               dev_err(dev, "failed to read step rate configuration rc=%d\n", rc);
>> +               return rc;
>> +       }
>> +       reg &= STEP_RATE_MASK;
>> +       pm8008_reg->step_rate = DEFAULT_VOLTAGE_STEPPER_RATE >> reg;
>> +
>> +       pm8008_reg->rdesc.type = REGULATOR_VOLTAGE;
>> +       pm8008_reg->rdesc.ops = &pm8008_regulator_ops;
>> +       pm8008_reg->rdesc.name = reg_data[i].name;
>> +       pm8008_reg->rdesc.supply_name = reg_data[i].supply_name;
>> +       pm8008_reg->rdesc.of_match = reg_data[i].name;
>> +       pm8008_reg->rdesc.uV_step = VSET_STEP_UV;
>> +       pm8008_reg->rdesc.linear_ranges = reg_data[i].voltage_range;
>> +       pm8008_reg->rdesc.n_linear_ranges = 1;
>> +
> Ideally the static assert is right here.


If I place it here below error is seen

error: ISO C90 forbids mixing declarations and code 
[-Werror,-Wdeclaration-after-statement]

It could be placed at the beginning  of this function near the 
declarations though. I see that many of the drivers add it below the 
array itself.