[RFC,v3,2/5] mfd: add driver for Marvell 88PM886 PMIC

From: Karel Balej <balejk@matfyz.cz>

Marvell 88PM886 is a PMIC which provides various functions such as
onkey, battery, charger and regulators. It is found for instance in the
samsung,coreprimevelte smartphone with which this was tested.

Only implement basic support to allow for the use of regulators and
onkey omitting the currently unused register definitions and I2C
subclients which should thus be added with the subdevice drivers which
need them.

Signed-off-by: Karel Balej <balejk@matfyz.cz>
---

Notes:
    RFC v3:
    - Drop onkey cell .of_compatible.
    - Rename LDO page offset and regmap to REGULATORS.
    RFC v2:
    - Remove some abstraction.
    - Sort includes alphabetically and add linux/of.h.
    - Depend on OF, remove of_match_ptr and add MODULE_DEVICE_TABLE.
    - Use more temporaries and break long lines.
    - Do not initialize ret in probe.
    - Use the wakeup-source DT property.
    - Rename ret to err.
    - Address Lee's comments:
      - Drop patched in presets for base regmap and related defines.
      - Use full sentences in comments.
      - Remove IRQ comment.
      - Define regmap_config member values.
      - Rename data to sys_off_data.
      - Add _PMIC suffix to Kconfig.
      - Use dev_err_probe.
      - Do not store irq_data.
      - s/WHOAMI/CHIP_ID
      - Drop LINUX part of include guard name.
      - Merge in the regulator series modifications in order to have more
        devices and modify the commit message accordingly. Changes with
        respect to the original regulator series patches:
        - ret -> err
        - Add temporary for dev in pm88x_initialize_subregmaps.
        - Drop of_compatible for the regulators.
        - Do not duplicate LDO regmap for bucks.
    - Rewrite commit message.

 drivers/mfd/88pm886.c       | 210 ++++++++++++++++++++++++++++++++++++
 drivers/mfd/Kconfig         |  12 +++
 drivers/mfd/Makefile        |   1 +
 include/linux/mfd/88pm886.h |  46 ++++++++
 4 files changed, 269 insertions(+)
 create mode 100644 drivers/mfd/88pm886.c
 create mode 100644 include/linux/mfd/88pm886.h

On Sun, 03 Mar 2024, Karel Balej wrote:

> From: Karel Balej <balejk@matfyz.cz>
> 
> Marvell 88PM886 is a PMIC which provides various functions such as
> onkey, battery, charger and regulators. It is found for instance in the
> samsung,coreprimevelte smartphone with which this was tested.
> 
> Only implement basic support to allow for the use of regulators and
> onkey omitting the currently unused register definitions and I2C
> subclients which should thus be added with the subdevice drivers which
> need them.
> 
> Signed-off-by: Karel Balej <balejk@matfyz.cz>
> ---
> 
> Notes:
>     RFC v3:
>     - Drop onkey cell .of_compatible.
>     - Rename LDO page offset and regmap to REGULATORS.
>     RFC v2:
>     - Remove some abstraction.
>     - Sort includes alphabetically and add linux/of.h.
>     - Depend on OF, remove of_match_ptr and add MODULE_DEVICE_TABLE.
>     - Use more temporaries and break long lines.
>     - Do not initialize ret in probe.
>     - Use the wakeup-source DT property.
>     - Rename ret to err.
>     - Address Lee's comments:
>       - Drop patched in presets for base regmap and related defines.
>       - Use full sentences in comments.
>       - Remove IRQ comment.
>       - Define regmap_config member values.
>       - Rename data to sys_off_data.
>       - Add _PMIC suffix to Kconfig.
>       - Use dev_err_probe.
>       - Do not store irq_data.
>       - s/WHOAMI/CHIP_ID

I still see 'whoami'.

>       - Drop LINUX part of include guard name.
>       - Merge in the regulator series modifications in order to have more
>         devices and modify the commit message accordingly. Changes with
>         respect to the original regulator series patches:
>         - ret -> err
>         - Add temporary for dev in pm88x_initialize_subregmaps.
>         - Drop of_compatible for the regulators.
>         - Do not duplicate LDO regmap for bucks.
>     - Rewrite commit message.
> 
>  drivers/mfd/88pm886.c       | 210 ++++++++++++++++++++++++++++++++++++
>  drivers/mfd/Kconfig         |  12 +++
>  drivers/mfd/Makefile        |   1 +
>  include/linux/mfd/88pm886.h |  46 ++++++++
>  4 files changed, 269 insertions(+)
>  create mode 100644 drivers/mfd/88pm886.c
>  create mode 100644 include/linux/mfd/88pm886.h
> 
> diff --git a/drivers/mfd/88pm886.c b/drivers/mfd/88pm886.c
> new file mode 100644
> index 000000000000..c17220e1b7e2
> --- /dev/null
> +++ b/drivers/mfd/88pm886.c
> @@ -0,0 +1,210 @@
> +// SPDX-License-Identifier: GPL-2.0-only

Header?  Description?  Author?  Copyright?

> +#include <linux/i2c.h>
> +#include <linux/mfd/core.h>
> +#include <linux/module.h>
> +#include <linux/notifier.h>
> +#include <linux/of.h>
> +#include <linux/reboot.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/mfd/88pm886.h>
> +
> +#define PM886_REG_INT_STATUS1			0x05
> +
> +#define PM886_REG_INT_ENA_1			0x0a
> +#define PM886_INT_ENA1_ONKEY			BIT(0)
> +
> +#define PM886_REGMAP_CONF_REG_BITS		8
> +#define PM886_REGMAP_CONF_VAL_BITS		8

These 2 are not commonly defined, just the one below please.

> +#define PM886_REGMAP_CONF_MAX_REG		0xfe

> +enum pm886_irq_number {
> +	PM886_IRQ_ONKEY,
> +
> +	PM886_MAX_IRQ
> +};

Seems superfluous for 1 IRQ and an unused MAX.

Looks like I've mentioned this before.

The IRQ number probably shouldn't be arbitrary either.

> +static struct regmap_irq pm886_regmap_irqs[] = {
> +	REGMAP_IRQ_REG(PM886_IRQ_ONKEY, 0, PM886_INT_ENA1_ONKEY),
> +};
> +
> +static struct regmap_irq_chip pm886_regmap_irq_chip = {
> +	.name = "88pm886",
> +	.irqs = pm886_regmap_irqs,
> +	.num_irqs = ARRAY_SIZE(pm886_regmap_irqs),
> +	.num_regs = 4,
> +	.status_base = PM886_REG_INT_STATUS1,
> +	.ack_base = PM886_REG_INT_STATUS1,
> +	.unmask_base = PM886_REG_INT_ENA_1,
> +};
> +
> +static struct resource pm886_onkey_resources[] = {
> +	DEFINE_RES_IRQ_NAMED(PM886_IRQ_ONKEY, "88pm886-onkey"),
> +};
> +
> +static struct mfd_cell pm886_devs[] = {
> +	{
> +		.name = "88pm886-onkey",
> +		.num_resources = ARRAY_SIZE(pm886_onkey_resources),
> +		.resources = pm886_onkey_resources,
> +	},
> +	{
> +		.name = "88pm886-regulator",
> +		.id = PM886_REGULATOR_ID_LDO2,

Why doesn't PLATFORM_DEVID_AUTO work for this device?

> +	},
> +	{
> +		.name = "88pm886-regulator",
> +		.id = PM886_REGULATOR_ID_LDO15,
> +	},
> +	{
> +		.name = "88pm886-regulator",
> +		.id = PM886_REGULATOR_ID_BUCK2,
> +	},
> +};
> +
> +static const struct regmap_config pm886_i2c_regmap = {
> +	.reg_bits = PM886_REGMAP_CONF_REG_BITS,
> +	.val_bits = PM886_REGMAP_CONF_VAL_BITS,
> +	.max_register = PM886_REGMAP_CONF_MAX_REG,
> +};
> +
/> +static int pm886_power_off_handler(struct sys_off_data *sys_off_data)
> +{
> +	struct pm886_chip *chip = sys_off_data->cb_data;
> +	struct regmap *regmap = chip->regmaps[PM886_REGMAP_BASE];
> +	struct device *dev = &chip->client->dev;
> +	int err;
> +
> +	err = regmap_update_bits(regmap, PM886_REG_MISC_CONFIG1, PM886_SW_PDOWN,
> +				PM886_SW_PDOWN);
> +	if (err) {
> +		dev_err(dev, "Failed to power off the device: %d\n", err);
> +		return NOTIFY_BAD;
> +	}
> +	return NOTIFY_DONE;
> +}
> +
> +static int pm886_initialize_subregmaps(struct pm886_chip *chip)
> +{
> +	struct device *dev = &chip->client->dev;
> +	struct i2c_client *page;
> +	struct regmap *regmap;
> +	int err;
> +
> +	/* regulators page */
> +	page = devm_i2c_new_dummy_device(dev, chip->client->adapter,
> +				chip->client->addr + PM886_PAGE_OFFSET_REGULATORS);
> +	if (IS_ERR(page)) {
> +		err = PTR_ERR(page);
> +		dev_err(dev, "Failed to initialize regulators client: %d\n", err);
> +		return err;
> +	}
> +	regmap = devm_regmap_init_i2c(page, &pm886_i2c_regmap);
> +	if (IS_ERR(regmap)) {
> +		err = PTR_ERR(regmap);
> +		dev_err(dev, "Failed to initialize regulators regmap: %d\n", err);
> +		return err;
> +	}
> +	chip->regmaps[PM886_REGMAP_REGULATORS] = regmap;

Except for the regulator driver, where else is the regulators regmap used?

> +
> +	return 0;
> +}
> +
> +static int pm886_setup_irq(struct pm886_chip *chip,
> +		struct regmap_irq_chip_data **irq_data)
> +{
> +	struct regmap *regmap = chip->regmaps[PM886_REGMAP_BASE];
> +	struct device *dev = &chip->client->dev;
> +	int err;
> +
> +	/* Set interrupt clearing mode to clear on write. */
> +	err = regmap_update_bits(regmap, PM886_REG_MISC_CONFIG2,
> +			PM886_INT_INV | PM886_INT_CLEAR | PM886_INT_MASK_MODE,
> +			PM886_INT_WC);
> +	if (err) {
> +		dev_err(dev, "Failed to set interrupt clearing mode: %d\n", err);
> +		return err;
> +	}
> +
> +	err = devm_regmap_add_irq_chip(dev, regmap, chip->client->irq,
> +					IRQF_ONESHOT, -1, &pm886_regmap_irq_chip,
> +					irq_data);
> +	if (err) {
> +		dev_err(dev, "Failed to request IRQ: %d\n", err);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int pm886_probe(struct i2c_client *client)
> +{
> +	struct regmap_irq_chip_data *irq_data;
> +	struct device *dev = &client->dev;
> +	struct pm886_chip *chip;
> +	struct regmap *regmap;
> +	unsigned int chip_id;
> +	int err;
> +
> +	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
> +	if (!chip)
> +		return -ENOMEM;
> +
> +	chip->client = client;
> +	chip->whoami = (uintptr_t)device_get_match_data(dev);
> +	i2c_set_clientdata(client, chip);
> +
> +	regmap = devm_regmap_init_i2c(client, &pm886_i2c_regmap);
> +	if (IS_ERR(regmap)) {
> +		err = PTR_ERR(regmap);
> +		return dev_err_probe(dev, err, "Failed to initialize regmap\n");
> +	}
> +	chip->regmaps[PM886_REGMAP_BASE] = regmap;
> +
> +	err = regmap_read(regmap, PM886_REG_ID, &chip_id);
> +	if (err)
> +		return dev_err_probe(dev, err, "Failed to read chip ID\n");

'\n'

> +	if (chip->whoami != chip_id)
> +		return dev_err_probe(dev, -EINVAL, "Device reported wrong chip ID: %u\n",

"Unsupported chip"

> +					chip_id);

How many chars does this take up if on one line?

Nit: If you have to break, break after the "-EINVAL" param.

> +
> +	err = pm886_initialize_subregmaps(chip);
> +	if (err)
> +		return err;
> +
> +	err = pm886_setup_irq(chip, &irq_data);
> +	if (err)
> +		return err;
> +
> +	err = devm_mfd_add_devices(dev, 0, pm886_devs, ARRAY_SIZE(pm886_devs),
> +				NULL, 0, regmap_irq_get_domain(irq_data));
> +	if (err)
> +		return dev_err_probe(dev, err, "Failed to add devices\n");
> +
> +	err = devm_register_power_off_handler(dev, pm886_power_off_handler, chip);
> +	if (err)
> +		return dev_err_probe(dev, err, "Failed to register power off handler\n");
> +
> +	device_init_wakeup(dev, device_property_read_bool(dev, "wakeup-source"));
> +
> +	return 0;
> +}
> +
> +const struct of_device_id pm886_of_match[] = {
> +	{ .compatible = "marvell,88pm886-a1", .data = (void *)PM886_A1_CHIP_ID },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, pm886_of_match);
> +
> +static struct i2c_driver pm886_i2c_driver = {
> +	.driver = {
> +		.name = "88pm886",
> +		.of_match_table = pm886_of_match,
> +	},
> +	.probe = pm886_probe,
> +};
> +module_i2c_driver(pm886_i2c_driver);
> +
> +MODULE_DESCRIPTION("Marvell 88PM886 PMIC driver");
> +MODULE_AUTHOR("Karel Balej <balejk@matfyz.cz>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index e7a6e45b9fac..9ef921c59f30 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -794,6 +794,18 @@ config MFD_88PM860X
>  	  select individual components like voltage regulators, RTC and
>  	  battery-charger under the corresponding menus.
>  
> +config MFD_88PM886_PMIC
> +	bool "Marvell 88PM886 PMIC"
> +	depends on I2C=y
> +	depends on OF
> +	select REGMAP_I2C
> +	select REGMAP_IRQ
> +	select MFD_CORE
> +	help
> +	  This enables support for Marvell 88PM886 Power Management IC.
> +	  This includes the I2C driver and the core APIs _only_, you have to
> +	  select individual components like onkey under the corresponding menus.
> +
>  config MFD_MAX14577
>  	tristate "Maxim Semiconductor MAX14577/77836 MUIC + Charger Support"
>  	depends on I2C
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index c66f07edcd0e..d016b7fed354 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -7,6 +7,7 @@
>  obj-$(CONFIG_MFD_88PM860X)	+= 88pm860x.o
>  obj-$(CONFIG_MFD_88PM800)	+= 88pm800.o 88pm80x.o
>  obj-$(CONFIG_MFD_88PM805)	+= 88pm805.o 88pm80x.o
> +obj-$(CONFIG_MFD_88PM886_PMIC)	+= 88pm886.o
>  obj-$(CONFIG_MFD_ACT8945A)	+= act8945a.o
>  obj-$(CONFIG_MFD_SM501)		+= sm501.o
>  obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835-pm.o
> diff --git a/include/linux/mfd/88pm886.h b/include/linux/mfd/88pm886.h
> new file mode 100644
> index 000000000000..c7527bab0fba
> --- /dev/null
> +++ b/include/linux/mfd/88pm886.h
> @@ -0,0 +1,46 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef __MFD_88PM886_H
> +#define __MFD_88PM886_H
> +
> +#include <linux/mfd/core.h>

What's this for?

> +#define PM886_A1_CHIP_ID		0xa1
> +
> +#define PM886_REG_ID			0x00
> +
> +#define PM886_REG_STATUS1		0x01
> +#define PM886_ONKEY_STS1		BIT(0)
> +
> +#define PM886_REG_MISC_CONFIG1		0x14
> +#define PM886_SW_PDOWN			BIT(5)
> +
> +#define PM886_REG_MISC_CONFIG2		0x15
> +#define PM886_INT_INV			BIT(0)
> +#define PM886_INT_CLEAR			BIT(1)
> +#define PM886_INT_RC			0x00
> +#define PM886_INT_WC			BIT(1)
> +#define PM886_INT_MASK_MODE		BIT(2)
> +
> +#define PM886_PAGE_OFFSET_REGULATORS	1
> +
> +enum pm886_regulator_id {
> +	PM886_REGULATOR_ID_LDO2,
> +	PM886_REGULATOR_ID_LDO15,
> +	PM886_REGULATOR_ID_BUCK2,
> +
> +	PM886_REGULATOR_ID_SENTINEL
> +};
> +
> +enum pm886_regmap_index {
> +	PM886_REGMAP_BASE,
> +	PM886_REGMAP_REGULATORS,
> +
> +	PM886_REGMAP_NR
> +};
> +
> +struct pm886_chip {
> +	struct i2c_client *client;
> +	unsigned int whoami;

chip_id

> +	struct regmap *regmaps[PM886_REGMAP_NR];
> +};
> +#endif /* __MFD_88PM886_H */
> -- 
> 2.44.0
>

Lee Jones, 2024-03-05T11:44:18+00:00:
> > +static struct mfd_cell pm886_devs[] = {
> > +	{
> > +		.name = "88pm886-onkey",
> > +		.num_resources = ARRAY_SIZE(pm886_onkey_resources),
> > +		.resources = pm886_onkey_resources,
> > +	},
> > +	{
> > +		.name = "88pm886-regulator",
> > +		.id = PM886_REGULATOR_ID_LDO2,
>
> Why doesn't PLATFORM_DEVID_AUTO work for this device?

Because I am using the IDs in the regulator driver to determine which
regulator data to use/which regulator to register.

> > +static int pm886_initialize_subregmaps(struct pm886_chip *chip)
> > +{
> > +	struct device *dev = &chip->client->dev;
> > +	struct i2c_client *page;
> > +	struct regmap *regmap;
> > +	int err;
> > +
> > +	/* regulators page */
> > +	page = devm_i2c_new_dummy_device(dev, chip->client->adapter,
> > +				chip->client->addr + PM886_PAGE_OFFSET_REGULATORS);
> > +	if (IS_ERR(page)) {
> > +		err = PTR_ERR(page);
> > +		dev_err(dev, "Failed to initialize regulators client: %d\n", err);
> > +		return err;
> > +	}
> > +	regmap = devm_regmap_init_i2c(page, &pm886_i2c_regmap);
> > +	if (IS_ERR(regmap)) {
> > +		err = PTR_ERR(regmap);
> > +		dev_err(dev, "Failed to initialize regulators regmap: %d\n", err);
> > +		return err;
> > +	}
> > +	chip->regmaps[PM886_REGMAP_REGULATORS] = regmap;
>
> Except for the regulator driver, where else is the regulators regmap used?

Nowhere, at least as of now. So you are saying that I should initialize
the regmap in the regulator driver?

Thank you,
K. B.

> > > +static int pm886_initialize_subregmaps(struct pm886_chip *chip)
> > > +{
> > > +	struct device *dev = &chip->client->dev;
> > > +	struct i2c_client *page;
> > > +	struct regmap *regmap;
> > > +	int err;
> > > +
> > > +	/* regulators page */
> > > +	page = devm_i2c_new_dummy_device(dev, chip->client->adapter,
> > > +				chip->client->addr + PM886_PAGE_OFFSET_REGULATORS);
> > > +	if (IS_ERR(page)) {
> > > +		err = PTR_ERR(page);
> > > +		dev_err(dev, "Failed to initialize regulators client: %d\n", err);
> > > +		return err;
> > > +	}
> > > +	regmap = devm_regmap_init_i2c(page, &pm886_i2c_regmap);
> > > +	if (IS_ERR(regmap)) {
> > > +		err = PTR_ERR(regmap);
> > > +		dev_err(dev, "Failed to initialize regulators regmap: %d\n", err);
> > > +		return err;
> > > +	}
> > > +	chip->regmaps[PM886_REGMAP_REGULATORS] = regmap;
> >
> > Except for the regulator driver, where else is the regulators regmap used?
> 
> Nowhere, at least as of now. So you are saying that I should initialize
> the regmap in the regulator driver?

I am.