Re: [PATCH v9 2/6] mfd: mp2629: Add support for mps battery charger

[Lee Jones <lee.jones@linaro.org>]

On Wed, 15 Apr 2020, Saravanan Sekar wrote:

> mp2629 is a highly-integrated switching-mode battery charge management
> device for single-cell Li-ion or Li-polymer battery.
> 
> Add MFD core enables chip access for ADC driver for battery readings,
> and a power supply battery-charger driver
> 
> Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
> ---
>  drivers/mfd/Kconfig        |  9 ++++
>  drivers/mfd/Makefile       |  2 +
>  drivers/mfd/mp2629.c       | 86 ++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/mp2629.h | 19 +++++++++
>  4 files changed, 116 insertions(+)
>  create mode 100644 drivers/mfd/mp2629.c
>  create mode 100644 include/linux/mfd/mp2629.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 3c547ed575e6..85be799795aa 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -434,6 +434,15 @@ config MFD_MC13XXX_I2C
>  	help
>  	  Select this if your MC13xxx is connected via an I2C bus.
>  
> +config MFD_MP2629
> +	tristate "Monolithic power system MP2629 ADC and Battery charger"

"Power Systems"

> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  Select this option to enable support for monolithic power system

"Monolithic Power Systems"

> +	  battery charger. This provides ADC, thermal, battery charger power

"thermal and battery"

> +	  management functions on the systems.

What does "on the systems" mean?

I would just drop that part.

>  config MFD_MXS_LRADC
>  	tristate "Freescale i.MX23/i.MX28 LRADC"
>  	depends on ARCH_MXS || COMPILE_TEST
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index f935d10cbf0f..d6c210f96d02 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -170,6 +170,8 @@ obj-$(CONFIG_MFD_MAX8925)	+= max8925.o
>  obj-$(CONFIG_MFD_MAX8997)	+= max8997.o max8997-irq.o
>  obj-$(CONFIG_MFD_MAX8998)	+= max8998.o max8998-irq.o
>  
> +obj-$(CONFIG_MFD_MP2629)	+= mp2629.o
> +
>  pcf50633-objs			:= pcf50633-core.o pcf50633-irq.o
>  obj-$(CONFIG_MFD_PCF50633)	+= pcf50633.o
>  obj-$(CONFIG_PCF50633_ADC)	+= pcf50633-adc.o
> diff --git a/drivers/mfd/mp2629.c b/drivers/mfd/mp2629.c
> new file mode 100644
> index 000000000000..46242b1cdf24
> --- /dev/null
> +++ b/drivers/mfd/mp2629.c
> @@ -0,0 +1,86 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * MP2629 parent driver for ADC and battery charger
> + *
> + * Copyright 2020 Monolithic Power Systems, Inc
> + *
> + * Author: Saravanan Sekar <sravanhome@gmail.com>
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/mp2629.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +enum {
> +	MP2629_MFD_ADC,
> +	MP2629_MFD_CHARGER,
> +	MP2629_MFD_MAX
> +};

Why do you need this?  I think it can be dropped.

> +static const struct mfd_cell mp2629mfd[] = {

Drop the "mfd" part of "mp2629mfd".

You can call it "mp2629_cell" if you like.

> +	[MP2629_MFD_ADC] = {
> +		.name = "mp2629_adc",
> +		.of_compatible = "mps,mp2629_adc",
> +	},
> +	[MP2629_MFD_CHARGER] = {
> +		.name = "mp2629_charger",
> +		.of_compatible = "mps,mp2629_charger",
> +	}
> +};
> +
> +static const struct regmap_config mp2629_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0x17,

Best to define the registers in an enum and call the last one
MP2629_MAX_REG or similar.

> +};
> +
> +static int mp2629_probe(struct i2c_client *client)
> +{
> +	struct mp2629_info *ddata;

Either change "info" to "ddata", or drop it completely.

> +	int ret;
> +
> +	ddata = devm_kzalloc(&client->dev, sizeof(*ddata), GFP_KERNEL);
> +	if (!ddata)
> +		return -ENOMEM;
> +
> +	ddata->dev = &client->dev;
> +	i2c_set_clientdata(client, ddata);
> +
> +	ddata->regmap = devm_regmap_init_i2c(client, &mp2629_regmap_config);
> +	if (IS_ERR(ddata->regmap)) {
> +		dev_err(ddata->dev, "Failed to allocate regmap!\n");

No need for the exclamation mark.

> +		return PTR_ERR(ddata->regmap);
> +	}
> +
> +	ret = devm_mfd_add_devices(ddata->dev, PLATFORM_DEVID_NONE, mp2629mfd,

Why NONE over AUTO?

> +				ARRAY_SIZE(mp2629mfd), NULL,
> +				0, NULL);
> +	if (ret)
> +		dev_err(ddata->dev, "Failed to register sub-devices %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static const struct of_device_id mp2629_of_match[] = {
> +	{ .compatible = "mps,mp2629"},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, mp2629_of_match);
> +
> +static struct i2c_driver mp2629_driver = {
> +	.driver = {
> +		.name = "mp2629",
> +		.of_match_table = mp2629_of_match,
> +	},
> +	.probe_new	= mp2629_probe,
> +};
> +module_i2c_driver(mp2629_driver);
> +
> +MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
> +MODULE_DESCRIPTION("MP2629 Battery charger parent driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/mp2629.h b/include/linux/mfd/mp2629.h
> new file mode 100644
> index 000000000000..06985e41fc6f
> --- /dev/null
> +++ b/include/linux/mfd/mp2629.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * register definitions for MP2629 charger

"Register"

Although there aren't any register definitions in here?

> + * Copyright 2020 Monolithic Power Systems, Inc
> + */
> +
> +#ifndef __MP2629_H__
> +#define __MP2629_H__
> +
> +#include <linux/device.h>
> +#include <linux/regmap.h>
> +
> +struct mp2629_info {
> +	struct device *dev;
> +	struct regmap *regmap;
> +};
> +
> +#endif

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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