Re: [PATCH v2 2/5] mfd: mp2629: Add support for mps battery charger

From: Jonathan Cameron
Date: Sun Mar 15 2020 - 06:28:06 EST


On Sun, 15 Mar 2020 01:00:10 +0100
Saravanan Sekar <sravanhome@xxxxxxxxx> 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@xxxxxxxxx>
> ---
> drivers/mfd/Kconfig | 9 ++++
> drivers/mfd/Makefile | 2 +
> drivers/mfd/mp2629.c | 96 ++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/mp2629.h | 32 +++++++++++++
> 4 files changed, 139 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..f3f0a2908f16 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
> + bool "Monolithic power system MP2629 ADC and Battery charger"
> + 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

battery (both instances don't need a capital)

> + management functions on the systems.
> +
> 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..47a37eadf25d
> --- /dev/null
> +++ b/drivers/mfd/mp2629.c
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * MP2629 MFD Driver for ADC and battery charger
> + *
> + * Copyright 2020 Monolithic Power Systems, Inc
> + *
> + * Author: Saravanan Sekar <sravanhome@xxxxxxxxx>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/irq.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/mp2629.h>
> +
> +enum {
> + MP2629_MFD_ADC,
> + MP2629_MFD_CHARGER,
> + MP2629_MFD_MAX
> +};
> +
> +static const struct mfd_cell mp2629mfd[] = {
> + [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,
> +};
> +
> +static int mp2629_probe(struct i2c_client *client)
> +{
> + struct mp2629_info *info;
> + int ret;
> +
> + info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> +
> + info->dev = &client->dev;
> + info->irq = client->irq;

This surprises me a bit given the irq isn't used in this driver at all.
Should it perhaps be provided directly to the child that uses it?
(Not sure myself, Lee?)

> + i2c_set_clientdata(client, info);
> +
> + info->regmap = devm_regmap_init_i2c(client, &mp2629_regmap_config);
> + if (IS_ERR(info->regmap)) {
> + dev_err(info->dev, "Failed to allocate regmap!\n");
> + return PTR_ERR(info->regmap);
> + }
> +
> + ret = devm_mfd_add_devices(info->dev, PLATFORM_DEVID_NONE, mp2629mfd,
> + ARRAY_SIZE(mp2629mfd), NULL,
> + 0, NULL);
> + if (ret)
> + dev_err(info->dev, "Failed to add mfd %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 const struct i2c_device_id mp2629_id[] = {
> + { "mp2629", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, mp2629_id);
> +
> +static struct i2c_driver mp2629_driver = {
> + .driver = {
> + .name = "mp2629",
> + .of_match_table = mp2629_of_match,
> + },
> + .probe_new = mp2629_probe,
> + .id_table = mp2629_id,
> +};
> +module_i2c_driver(mp2629_driver);
> +
> +MODULE_AUTHOR("Saravanan Sekar <sravanhome@xxxxxxxxx>");
> +MODULE_DESCRIPTION("MP2629 Battery charger mfd driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/mp2629.h b/include/linux/mfd/mp2629.h
> new file mode 100644
> index 000000000000..32f0737f245e
> --- /dev/null
> +++ b/include/linux/mfd/mp2629.h
> @@ -0,0 +1,32 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * mp2629.h - register definitions for mp2629 charger
> + *
> + * Copyright 2020 Monolithic Power Systems, Inc
> + *
> + */
> +
> +#ifndef __MP2629_H__
> +#define __MP2629_H__
> +
> +#include <linux/types.h>
> +
> +struct device;
> +struct regmap;
> +
> +struct mp2629_info {
> + struct device *dev;
> + struct regmap *regmap;
> + int irq;
> +};
> +
> +enum mp2629_adc_chan {
> + MP2629_BATT_VOLT,
> + MP2629_SYSTEM_VOLT,
> + MP2629_INPUT_VOLT,
> + MP2629_BATT_CURRENT,
> + MP2629_INPUT_CURRENT,
> + MP2629_ADC_CHAN_END
> +};

This enum isn't used in this patch. I'd slightly prefer it to be introduced
with the first user.

> +
> +#endif