Re: [PATCH v2 3/3] regulator: mt6315: Add support for MT6315 regulator

From: Nicolas Boichat
Date: Tue Nov 10 2020 - 23:42:08 EST

A number of comments, we might need another pass after you address
Rob's comments too.

On Tue, Oct 20, 2020 at 5:57 PM Hsin-Hsiung Wang
<hsin-hsiung.wang@xxxxxxxxxxxx> wrote:
>
> The MT6315 is a regulator found on boards based on MediaTek MT8192 and
> probably other SoCs. It connects as a slave to SoC using SPMI.
>
> Signed-off-by: Hsin-Hsiung Wang <hsin-hsiung.wang@xxxxxxxxxxxx>
> ---
> drivers/regulator/Kconfig | 10 +
> drivers/regulator/Makefile | 1 +
> drivers/regulator/mt6315-regulator.c | 364 +++++++++++++++++++++
> include/linux/regulator/mt6315-regulator.h | 37 +++
> 4 files changed, 412 insertions(+)
> create mode 100644 drivers/regulator/mt6315-regulator.c
> create mode 100644 include/linux/regulator/mt6315-regulator.h
>
> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
> index de17ef7e18f0..59544918034e 100644
> --- a/drivers/regulator/Kconfig
> +++ b/drivers/regulator/Kconfig
> @@ -693,6 +693,16 @@ config REGULATOR_MT6311
> This driver supports the control of different power rails of device
> through regulator interface.
>
> +config REGULATOR_MT6315
> + tristate "MediaTek MT6315 PMIC"
> + depends on SPMI
> + select REGMAP_SPMI
> + help
> + Say y here to select this option to enable the power regulator of
> + MediaTek MT6315 PMIC.
> + This driver supports the control of different power rails of device
> + through regulator interface.
> +
> config REGULATOR_MT6323
> tristate "MediaTek MT6323 PMIC"
> depends on MFD_MT6397
> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
> index d8d3ecf526a8..5488e563c60a 100644
> --- a/drivers/regulator/Makefile
> +++ b/drivers/regulator/Makefile
> @@ -86,6 +86,7 @@ obj-$(CONFIG_REGULATOR_MP8859) += mp8859.o
> obj-$(CONFIG_REGULATOR_MP886X) += mp886x.o
> obj-$(CONFIG_REGULATOR_MPQ7920) += mpq7920.o
> obj-$(CONFIG_REGULATOR_MT6311) += mt6311-regulator.o
> +obj-$(CONFIG_REGULATOR_MT6315) += mt6315-regulator.o
> obj-$(CONFIG_REGULATOR_MT6323) += mt6323-regulator.o
> obj-$(CONFIG_REGULATOR_MT6358) += mt6358-regulator.o
> obj-$(CONFIG_REGULATOR_MT6380) += mt6380-regulator.o
> diff --git a/drivers/regulator/mt6315-regulator.c b/drivers/regulator/mt6315-regulator.c
> new file mode 100644
> index 000000000000..8e3accb2e36f
> --- /dev/null
> +++ b/drivers/regulator/mt6315-regulator.c
> @@ -0,0 +1,364 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (c) 2020 MediaTek Inc.
> +
> +#include <dt-bindings/regulator/mtk,mt6315.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/driver.h>
> +#include <linux/regulator/machine.h>
> +#include <linux/regulator/mt6315-regulator.h>
> +#include <linux/regulator/of_regulator.h>
> +#include <linux/spmi.h>
> +
> +#define MT6315_REG_WIDTH 8
> +
> +#define MT6315_BUCK_MODE_AUTO 0
> +#define MT6315_BUCK_MODE_FORCE_PWM 1
> +#define MT6315_BUCK_MODE_LP 2
> +
> +struct mt6315_regulator_info {
> + struct regulator_desc desc;
> + u32 da_vsel_reg;
> + u32 da_reg;
> + u32 lp_mode_reg;

Always MT6315_BUCK_TOP_CON1, do you really need a field for that?

> + u32 lp_mode_mask;
> + u32 lp_mode_shift;
> + u32 modeset_reg;

ditto, always MT6315_BUCK_TOP_4PHASE_ANA_CON42.

> + u32 qi;

qi always seems to be BIT(0), do you really need this field?

If so, please use a better name than qi (I'm not sure what that means).

> +};
> +
> +struct mt_regulator_init_data {
> + const struct mt6315_regulator_info *regulator_info;
> + u32 modeset_mask[MT6315_VBUCK_MAX];
> +};
> +
> +struct mt6315_chip {
> + struct device *dev;
> + struct regmap *regmap;
> +};
> +
> +#define MT_BUCK(_name, _bid, _vsel) \
> +[_bid] = { \
> + .desc = { \
> + .name = _name, \
> + .of_match = of_match_ptr(_name), \
> + .regulators_node = "regulators", \
> + .ops = &mt6315_volt_range_ops, \
> + .type = REGULATOR_VOLTAGE, \
> + .id = _bid, \
> + .owner = THIS_MODULE, \
> + .n_voltages = 0xbf, \
> + .linear_ranges = mt_volt_range1, \
> + .n_linear_ranges = ARRAY_SIZE(mt_volt_range1), \
> + .vsel_reg = _vsel, \
> + .vsel_mask = 0xff, \
> + .enable_reg = MT6315_BUCK_TOP_CON0, \
> + .enable_mask = BIT(_bid - 1), \
> + .of_map_mode = mt6315_map_mode, \
> + }, \
> + .da_vsel_reg = _bid##_DBG0, \
> + .da_reg = _bid##_DBG4, \
> + .lp_mode_reg = MT6315_BUCK_TOP_CON1, \
> + .lp_mode_mask = BIT(_bid - 1), \
> + .lp_mode_shift = _bid - 1, \
> + .modeset_reg = MT6315_BUCK_TOP_4PHASE_ANA_CON42, \
> + .qi = BIT(0), \
> +}
> +
> +static const struct linear_range mt_volt_range1[] = {
> + REGULATOR_LINEAR_RANGE(0, 0, 0xbf, 6250),
> +};
> +
> +static unsigned int mt6315_map_mode(u32 mode)
> +{
> + switch (mode) {
> + case MT6315_BUCK_MODE_AUTO:
> + return REGULATOR_MODE_NORMAL;
> + case MT6315_BUCK_MODE_FORCE_PWM:
> + return REGULATOR_MODE_FAST;
> + case MT6315_BUCK_MODE_LP:
> + return REGULATOR_MODE_IDLE;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int mt6315_regulator_get_voltage_sel(struct regulator_dev *rdev)
> +{
> + struct mt_regulator_init_data *init = rdev_get_drvdata(rdev);
> + const struct mt6315_regulator_info *info;
> + int ret, reg_addr, reg_val = 0, reg_en = 0;
> +
> + info = &init->regulator_info[rdev_get_id(rdev)];
> + ret = regmap_read(rdev->regmap, info->da_reg, &reg_en);
> + if (ret != 0) {
> + dev_notice(&rdev->dev, "Failed to get enable reg: %d\n", ret);
> + return ret;
> + }
> +
> + if (reg_en & info->qi)
> + reg_addr = info->da_vsel_reg;
> + else
> + reg_addr = rdev->desc->vsel_reg;
> +
> + ret = regmap_read(rdev->regmap, reg_addr, &reg_val);
> + if (ret != 0) {
> + dev_notice(&rdev->dev, "Failed to get voltage: %d\n", ret);
> + return ret;
> + }
> +
> + ret = reg_val & rdev->desc->vsel_mask;
> + return ret;
> +}
> +
> +static unsigned int mt6315_regulator_get_mode(struct regulator_dev *rdev)
> +{
> + struct mt_regulator_init_data *init = rdev_get_drvdata(rdev);
> + const struct mt6315_regulator_info *info;
> + int ret = 0, regval = 0;
> + u32 modeset_mask;
> +
> + info = &init->regulator_info[rdev_get_id(rdev)];
> + modeset_mask = init->modeset_mask[rdev_get_id(rdev)];
> + ret = regmap_read(rdev->regmap, info->modeset_reg, &regval);
> + if (ret != 0) {
> + dev_notice(&rdev->dev, "Failed to get mode: %d\n", ret);
> + return ret;
> + }
> +
> + if ((regval & modeset_mask) == modeset_mask)
> + return REGULATOR_MODE_FAST;
> +
> + ret = regmap_read(rdev->regmap, info->lp_mode_reg, &regval);
> + if (ret != 0) {
> + dev_notice(&rdev->dev, "Failed to get lp mode: %d\n", ret);
> + return ret;
> + }
> +
> + if (regval & info->lp_mode_mask)
> + return REGULATOR_MODE_IDLE;
> + else
> + return REGULATOR_MODE_NORMAL;
> +}
> +
> +static int mt6315_regulator_set_mode(struct regulator_dev *rdev,
> + u32 mode)
> +{
> + struct mt_regulator_init_data *init = rdev_get_drvdata(rdev);
> + const struct mt6315_regulator_info *info;
> + int ret = 0

No need to set ret to 0 (it allows the compiler to figure out that ret
is set in all paths, which is good).

, val, curr_mode;
> + u32 modeset_mask;
> +
> + info = &init->regulator_info[rdev_get_id(rdev)];
> + modeset_mask = init->modeset_mask[rdev_get_id(rdev)];
> + curr_mode = mt6315_regulator_get_mode(rdev);
> + switch (mode) {
> + case REGULATOR_MODE_FAST:
> + ret = regmap_update_bits(rdev->regmap,
> + info->modeset_reg,
> + modeset_mask,
> + modeset_mask);
> + break;
> + case REGULATOR_MODE_NORMAL:
> + if (curr_mode == REGULATOR_MODE_FAST) {
> + ret = regmap_update_bits(rdev->regmap,
> + info->modeset_reg,
> + modeset_mask,
> + 0);
> + } else if (curr_mode == REGULATOR_MODE_IDLE) {
> + ret = regmap_update_bits(rdev->regmap,
> + info->lp_mode_reg,
> + info->lp_mode_mask,
> + 0);
> + usleep_range(100, 110);
> + }
> + break;
> + case REGULATOR_MODE_IDLE:
> + val = MT6315_BUCK_MODE_LP >> 1;
> + val <<= info->lp_mode_shift;
> + ret = regmap_update_bits(rdev->regmap,
> + info->lp_mode_reg,
> + info->lp_mode_mask,
> + val);
> + break;
> + default:
> + ret = -EINVAL;
> + goto err_mode;

Not needed, just break and let it continue.

> + }
> +
> +err_mode:
> + if (ret != 0) {
> + dev_notice(&rdev->dev, "Failed to set mode: %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int mt6315_get_status(struct regulator_dev *rdev)
> +{
> + struct mt_regulator_init_data *init = rdev_get_drvdata(rdev);
> + const struct mt6315_regulator_info *info;
> + int ret = 0;

No need to set to 0.

> + u32 regval = 0;
> +
> + info = &init->regulator_info[rdev_get_id(rdev)];
> + ret = regmap_read(rdev->regmap, info->da_reg, &regval);
> + if (ret != 0) {

< 0 ? Just want to make sure we don't accidentally return a positive value.

> + dev_notice(&rdev->dev, "Failed to get enable reg: %d\n", ret);
> + return ret;
> + }
> +
> + return (regval & info->qi) ? REGULATOR_STATUS_ON : REGULATOR_STATUS_OFF;
> +}
> +
> +static const struct regulator_ops mt6315_volt_range_ops = {
> + .list_voltage = regulator_list_voltage_linear_range,
> + .map_voltage = regulator_map_voltage_linear_range,
> + .set_voltage_sel = regulator_set_voltage_sel_regmap,
> + .get_voltage_sel = mt6315_regulator_get_voltage_sel,
> + .set_voltage_time_sel = regulator_set_voltage_time_sel,
> + .enable = regulator_enable_regmap,
> + .disable = regulator_disable_regmap,
> + .is_enabled = regulator_is_enabled_regmap,
> + .get_status = mt6315_get_status,
> + .set_mode = mt6315_regulator_set_mode,
> + .get_mode = mt6315_regulator_get_mode,
> +};
> +
> +static const struct mt6315_regulator_info mt6315_regulators[MT6315_VBUCK_MAX] = {
> + MT_BUCK("vbuck1", MT6315_VBUCK1, MT6315_BUCK_TOP_ELR0),
> + MT_BUCK("vbuck2", MT6315_VBUCK2, MT6315_BUCK_TOP_ELR2),
> + MT_BUCK("vbuck3", MT6315_VBUCK3, MT6315_BUCK_TOP_ELR4),
> + MT_BUCK("vbuck4", MT6315_VBUCK4, MT6315_BUCK_TOP_ELR6),
> +};
> +
> +static const struct regmap_config mt6315_regmap_config = {
> + .reg_bits = 16,
> + .val_bits = 8,
> + .max_register = 0x16d0,
> + .fast_io = true,
> +};
> +
> +static const struct of_device_id mt6315_of_match[] = {
> + {
> + .compatible = "mediatek,mt6315_3-regulator",
> + }, {
> + .compatible = "mediatek,mt6315_6-regulator",
> + }, {
> + .compatible = "mediatek,mt6315_7-regulator",

Rob already commented on the binding, but I don't think you need 3
compatibles if you don't do anything different for any of them.

(and as I highlighted before, the compatible name should, IMHO, be the
part number, not the address)

> + }, {
> + /* sentinel */
> + },
> +};
> +MODULE_DEVICE_TABLE(of, mt6315_of_match);
> +
> +static void mt6315_parsing_dt(struct regulator_dev *rdev

mt6315_parse_dt

Or maybe mt6315_parse_vbuck_dt since this acts on a single regulator/buck?

> , u32 *arr)

u32 *used_vbuck_list

> +{
> + struct device_node *np;
> + struct mt_regulator_init_data *init = rdev_get_drvdata(rdev);
> + u32 buck_id, *modeset;
> + int i, icount;

combined_count?

> +
> + np = rdev->dev.of_node;
> + if (!np)
> + return;
> +
> + icount = of_property_count_elems_of_size(np, "mtk,combined-regulator", sizeof(u32));
> + if (icount <= 0)
> + return;
> +
> + modeset = &init->modeset_mask[rdev_get_id(rdev)];

That's not super readable IMHO.

I'd just

int main_id = rdev_get_id(rdev);
then
init->modeset_mask[main_id] |= BIT(buck_id - 1);

> + for (i = 0; i < icount; i++) {
> + if (of_property_read_u32_index(np, "mtk,combined-regulator", i, &buck_id))
> + return;
> +
> + if (buck_id < MT6315_VBUCK_MAX) {
> + /* white list */

/* mark as used */

> + *(arr + buck_id) = 1;

used_vbuck_list[buck_id] = 1;

And maybe first check that used_vbuck_list[buck_id] == 0?

> + /* add modeset bit of combined-regulator */
> + *modeset += BIT(buck_id - 1);

|=

> + }
> + }
> +}
> +
> +static int mt6315_regulator_probe(struct spmi_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct regmap *regmap;
> + struct mt6315_chip *chip;
> + struct mt_regulator_init_data *init_data;
> + struct regulator_config config = {};
> + struct regulator_dev *rdev;
> + int i;
> + u32 mt6315_dt_list[MT6315_VBUCK_MAX] = {0};

used_vbuck_list

> +
> + regmap = devm_regmap_init_spmi_ext(pdev, &mt6315_regmap_config);
> + if (!regmap)
> + return -ENODEV;
> +
> + chip = devm_kzalloc(dev, sizeof(struct mt6315_chip), GFP_KERNEL);
> + if (!chip)
> + return -ENOMEM;
> +
> + init_data = devm_kzalloc(dev, sizeof(struct mt_regulator_init_data), GFP_KERNEL);
> + if (!init_data)
> + return -ENOMEM;
> +
> + chip->dev = dev;
> + chip->regmap = regmap;
> + dev_set_drvdata(dev, chip);
> +
> + config.dev = dev;
> + config.regmap = regmap;
> + init_data->regulator_info = mt6315_regulators;
> + for (i = MT6315_VBUCK1; i < MT6315_VBUCK_MAX; i++) {
> + if (mt6315_dt_list[i])
> + continue;
> +
> + init_data->modeset_mask[i] = 1 << (i - 1);
> + config.driver_data = init_data;
> + rdev = devm_regulator_register(dev, &mt6315_regulators[i].desc, &config);
> + if (IS_ERR(rdev)) {
> + dev_notice(dev, "Failed to register %s\n", mt6315_regulators[i].desc.name);
> + continue;
> + }
> + mt6315_parsing_dt(rdev, mt6315_dt_list);
> + }
> + return 0;
> +}
> +
> +static void mt6315_regulator_shutdown(struct spmi_device *pdev)
> +{
> + struct mt6315_chip *chip = dev_get_drvdata(&pdev->dev);
> + int ret = 0;
> +
> + ret |= regmap_write(chip->regmap, MT6315_TOP_TMA_KEY_H, PROTECTION_KEY_H);
> + ret |= regmap_write(chip->regmap, MT6315_TOP_TMA_KEY, PROTECTION_KEY);
> + ret |= regmap_update_bits(chip->regmap, MT6315_TOP2_ELR7, 1, 1);
> + ret |= regmap_write(chip->regmap, MT6315_TOP_TMA_KEY, 0);
> + ret |= regmap_write(chip->regmap, MT6315_TOP_TMA_KEY_H, 0);
> + if (ret < 0)
> + dev_notice(&pdev->dev, "[%#x] Failed to enable power off sequence. %d\n",
> + pdev->usid, ret);
> +}
> +
> +static struct spmi_driver mt6315_regulator_driver = {
> + .driver = {
> + .name = "mt6315-regulator",
> + .of_match_table = mt6315_of_match,
> + },
> + .probe = mt6315_regulator_probe,
> + .shutdown = mt6315_regulator_shutdown,
> +};
> +
> +module_spmi_driver(mt6315_regulator_driver);
> +
> +MODULE_AUTHOR("Hsin-Hsiung Wang <hsin-hsiung.wang@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Regulator Driver for MediaTek MT6315 PMIC");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/regulator/mt6315-regulator.h b/include/linux/regulator/mt6315-regulator.h
> new file mode 100644
> index 000000000000..4b3bd172cba1
> --- /dev/null
> +++ b/include/linux/regulator/mt6315-regulator.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2020 MediaTek Inc.
> + */
> +
> +#ifndef __LINUX_REGULATOR_MT6315_H
> +#define __LINUX_REGULATOR_MT6315_H
> +
> +#define MT6315_SLAVE_ID_3 3
> +#define MT6315_SLAVE_ID_6 6
> +#define MT6315_SLAVE_ID_7 7
> +
> +/* Register */
> +#define MT6315_SWCID_H 0xb
> +#define MT6315_TOP2_ELR7 0x139
> +#define MT6315_TOP_TMA_KEY 0x39f
> +#define MT6315_TOP_TMA_KEY_H 0x3a0
> +#define MT6315_BUCK_TOP_CON0 0x1440
> +#define MT6315_BUCK_TOP_CON1 0x1443
> +#define MT6315_BUCK_TOP_ELR0 0x1449
> +#define MT6315_BUCK_TOP_ELR2 0x144b
> +#define MT6315_BUCK_TOP_ELR4 0x144d
> +#define MT6315_BUCK_TOP_ELR6 0x144f
> +#define MT6315_VBUCK1_DBG0 0x1499
> +#define MT6315_VBUCK1_DBG4 0x149d
> +#define MT6315_VBUCK2_DBG0 0x1519
> +#define MT6315_VBUCK2_DBG4 0x151d
> +#define MT6315_VBUCK3_DBG0 0x1599
> +#define MT6315_VBUCK3_DBG4 0x159d
> +#define MT6315_VBUCK4_DBG0 0x1619
> +#define MT6315_VBUCK4_DBG4 0x161d
> +#define MT6315_BUCK_TOP_4PHASE_ANA_CON42 0x16b1
> +
> +#define PROTECTION_KEY_H 0x9C
> +#define PROTECTION_KEY 0xEA
> +
> +#endif /* __LINUX_REGULATOR_MT6315_H */
> --
> 2.18.0