Re: [PATCH v6 4/9] mfd: axp20x: Split the driver into core and i2c bits

From: Lee Jones
Date: Mon Jan 11 2016 - 04:25:46 EST


On Thu, 17 Dec 2015, Chen-Yu Tsai wrote:

> The axp20x driver assumes the device is i2c based. This is not the
> case with later chips, which use a proprietary 2 wire serial bus
> by Allwinner called "Reduced Serial Bus".
>
> This patch follows the example of mfd/wm831x and splits it into
> an interface independent core, and an i2c specific glue layer.
> MFD_AXP20X and the new MFD_AXP20X_I2C are changed to tristate
> symbols, allowing the driver to be built as modules.
>
> Whitespace and other style errors in the moved i2c specific code
> have been fixed. Included but unused header files are removed as
> well.
>
> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
> ---
> drivers/mfd/Kconfig | 14 ++++---
> drivers/mfd/Makefile | 1 +
> drivers/mfd/axp20x-i2c.c | 102 +++++++++++++++++++++++++++++++++++++++++++++
> drivers/mfd/axp20x.c | 88 +++++++-------------------------------
> include/linux/mfd/axp20x.h | 33 ++++++++++++++-
> 5 files changed, 158 insertions(+), 80 deletions(-)
> create mode 100644 drivers/mfd/axp20x-i2c.c

Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>

> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 4d92df6ef9fe..804cd3dcce32 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -91,14 +91,18 @@ config MFD_BCM590XX
> Support for the BCM590xx PMUs from Broadcom
>
> config MFD_AXP20X
> - bool "X-Powers AXP20X"
> + tristate
> select MFD_CORE
> - select REGMAP_I2C
> select REGMAP_IRQ
> - depends on I2C=y
> +
> +config MFD_AXP20X_I2C
> + tristate "X-Powers AXP series PMICs with I2C"
> + select MFD_AXP20X
> + select REGMAP_I2C
> + depends on I2C
> help
> - If you say Y here you get support for the X-Powers AXP202, AXP209 and
> - AXP288 power management IC (PMIC).
> + If you say Y here you get support for the X-Powers AXP series power
> + management ICs (PMICs) controlled with I2C.
> This driver include only the core APIs. You have to select individual
> components like regulators or the PEK (Power Enable Key) under the
> corresponding menus.
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index a8b76b81b467..a6913007d667 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -107,6 +107,7 @@ obj-$(CONFIG_PMIC_DA9052) += da9052-core.o
> obj-$(CONFIG_MFD_DA9052_SPI) += da9052-spi.o
> obj-$(CONFIG_MFD_DA9052_I2C) += da9052-i2c.o
> obj-$(CONFIG_MFD_AXP20X) += axp20x.o
> +obj-$(CONFIG_MFD_AXP20X_I2C) += axp20x-i2c.o
>
> obj-$(CONFIG_MFD_LP3943) += lp3943.o
> obj-$(CONFIG_MFD_LP8788) += lp8788.o lp8788-irq.o
> diff --git a/drivers/mfd/axp20x-i2c.c b/drivers/mfd/axp20x-i2c.c
> new file mode 100644
> index 000000000000..b54205677bb2
> --- /dev/null
> +++ b/drivers/mfd/axp20x-i2c.c
> @@ -0,0 +1,102 @@
> +/*
> + * axp20x-i2c.c - I2C driver for the X-Powers' Power Management ICs
> + *
> + * AXP20x typically comprises an adaptive USB-Compatible PWM charger, BUCK DC-DC
> + * converters, LDOs, multiple 12-bit ADCs of voltage, current and temperature
> + * as well as configurable GPIOs.
> + *
> + * This driver supports the I2C variants.
> + *
> + * Author: Carlo Caione <carlo@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/mfd/axp20x.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +static int axp20x_i2c_probe(struct i2c_client *i2c,
> + const struct i2c_device_id *id)
> +{
> + struct axp20x_dev *axp20x;
> + int ret;
> +
> + axp20x = devm_kzalloc(&i2c->dev, sizeof(*axp20x), GFP_KERNEL);
> + if (!axp20x)
> + return -ENOMEM;
> +
> + axp20x->dev = &i2c->dev;
> + axp20x->irq = i2c->irq;
> + dev_set_drvdata(axp20x->dev, axp20x);
> +
> + ret = axp20x_match_device(axp20x);
> + if (ret)
> + return ret;
> +
> + axp20x->regmap = devm_regmap_init_i2c(i2c, axp20x->regmap_cfg);
> + if (IS_ERR(axp20x->regmap)) {
> + ret = PTR_ERR(axp20x->regmap);
> + dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
> + return ret;
> + }
> +
> + return axp20x_device_probe(axp20x);
> +}
> +
> +static int axp20x_i2c_remove(struct i2c_client *i2c)
> +{
> + struct axp20x_dev *axp20x = i2c_get_clientdata(i2c);
> +
> + return axp20x_device_remove(axp20x);
> +}
> +
> +static const struct of_device_id axp20x_i2c_of_match[] = {
> + { .compatible = "x-powers,axp152", .data = (void *)AXP152_ID },
> + { .compatible = "x-powers,axp202", .data = (void *)AXP202_ID },
> + { .compatible = "x-powers,axp209", .data = (void *)AXP209_ID },
> + { .compatible = "x-powers,axp221", .data = (void *)AXP221_ID },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, axp20x_i2c_of_match);
> +
> +/*
> + * This is useless for OF-enabled devices, but it is needed by I2C subsystem
> + */
> +static const struct i2c_device_id axp20x_i2c_id[] = {
> + { },
> +};
> +MODULE_DEVICE_TABLE(i2c, axp20x_i2c_id);
> +
> +static const struct acpi_device_id axp20x_i2c_acpi_match[] = {
> + {
> + .id = "INT33F4",
> + .driver_data = AXP288_ID,
> + },
> + { },
> +};
> +MODULE_DEVICE_TABLE(acpi, axp20x_i2c_acpi_match);
> +
> +static struct i2c_driver axp20x_i2c_driver = {
> + .driver = {
> + .name = "axp20x-i2c",
> + .of_match_table = of_match_ptr(axp20x_i2c_of_match),
> + .acpi_match_table = ACPI_PTR(axp20x_i2c_acpi_match),
> + },
> + .probe = axp20x_i2c_probe,
> + .remove = axp20x_i2c_remove,
> + .id_table = axp20x_i2c_id,
> +};
> +
> +module_i2c_driver(axp20x_i2c_driver);
> +
> +MODULE_DESCRIPTION("PMIC MFD I2C driver for AXP20X");
> +MODULE_AUTHOR("Carlo Caione <carlo@xxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> index 3e186f2dcac3..631ad64ddf69 100644
> --- a/drivers/mfd/axp20x.c
> +++ b/drivers/mfd/axp20x.c
> @@ -5,6 +5,8 @@
> * converters, LDOs, multiple 12-bit ADCs of voltage, current and temperature
> * as well as configurable GPIOs.
> *
> + * This file contains the interface independent core functions.
> + *
> * Author: Carlo Caione <carlo@xxxxxxxxxx>
> *
> * This program is free software; you can redistribute it and/or modify
> @@ -13,18 +15,15 @@
> */
>
> #include <linux/err.h>
> -#include <linux/i2c.h>
> #include <linux/interrupt.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/pm_runtime.h>
> #include <linux/regmap.h>
> -#include <linux/slab.h>
> #include <linux/regulator/consumer.h>
> #include <linux/mfd/axp20x.h>
> #include <linux/mfd/core.h>
> #include <linux/of_device.h>
> -#include <linux/of_irq.h>
> #include <linux/acpi.h>
>
> #define AXP20X_OFF 0x80
> @@ -376,32 +375,6 @@ static const struct regmap_irq axp288_regmap_irqs[] = {
> INIT_REGMAP_IRQ(AXP288, BC_USB_CHNG, 5, 1),
> };
>
> -static const struct of_device_id axp20x_of_match[] = {
> - { .compatible = "x-powers,axp152", .data = (void *) AXP152_ID },
> - { .compatible = "x-powers,axp202", .data = (void *) AXP202_ID },
> - { .compatible = "x-powers,axp209", .data = (void *) AXP209_ID },
> - { .compatible = "x-powers,axp221", .data = (void *) AXP221_ID },
> - { },
> -};
> -MODULE_DEVICE_TABLE(of, axp20x_of_match);
> -
> -/*
> - * This is useless for OF-enabled devices, but it is needed by I2C subsystem
> - */
> -static const struct i2c_device_id axp20x_i2c_id[] = {
> - { },
> -};
> -MODULE_DEVICE_TABLE(i2c, axp20x_i2c_id);
> -
> -static const struct acpi_device_id axp20x_acpi_match[] = {
> - {
> - .id = "INT33F4",
> - .driver_data = AXP288_ID,
> - },
> - { },
> -};
> -MODULE_DEVICE_TABLE(acpi, axp20x_acpi_match);
> -
> static const struct regmap_irq_chip axp152_regmap_irq_chip = {
> .name = "axp152_irq_chip",
> .status_base = AXP152_IRQ1_STATE,
> @@ -606,7 +579,7 @@ static void axp20x_power_off(void)
> AXP20X_OFF);
> }
>
> -static int axp20x_match_device(struct axp20x_dev *axp20x)
> +int axp20x_match_device(struct axp20x_dev *axp20x)
> {
> struct device *dev = axp20x->dev;
> const struct acpi_device_id *acpi_id;
> @@ -663,38 +636,18 @@ static int axp20x_match_device(struct axp20x_dev *axp20x)
>
> return 0;
> }
> +EXPORT_SYMBOL(axp20x_match_device);
>
> -static int axp20x_i2c_probe(struct i2c_client *i2c,
> - const struct i2c_device_id *id)
> +int axp20x_device_probe(struct axp20x_dev *axp20x)
> {
> - struct axp20x_dev *axp20x;
> int ret;
>
> - axp20x = devm_kzalloc(&i2c->dev, sizeof(*axp20x), GFP_KERNEL);
> - if (!axp20x)
> - return -ENOMEM;
> -
> - axp20x->i2c_client = i2c;
> - axp20x->dev = &i2c->dev;
> - dev_set_drvdata(axp20x->dev, axp20x);
> -
> - ret = axp20x_match_device(axp20x);
> - if (ret)
> - return ret;
> -
> - axp20x->regmap = devm_regmap_init_i2c(i2c, axp20x->regmap_cfg);
> - if (IS_ERR(axp20x->regmap)) {
> - ret = PTR_ERR(axp20x->regmap);
> - dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
> - return ret;
> - }
> -
> - ret = regmap_add_irq_chip(axp20x->regmap, i2c->irq,
> + ret = regmap_add_irq_chip(axp20x->regmap, axp20x->irq,
> IRQF_ONESHOT | IRQF_SHARED, -1,
> axp20x->regmap_irq_chip,
> &axp20x->regmap_irqc);
> if (ret) {
> - dev_err(&i2c->dev, "failed to add irq chip: %d\n", ret);
> + dev_err(axp20x->dev, "failed to add irq chip: %d\n", ret);
> return ret;
> }
>
> @@ -702,8 +655,8 @@ static int axp20x_i2c_probe(struct i2c_client *i2c,
> axp20x->nr_cells, NULL, 0, NULL);
>
> if (ret) {
> - dev_err(&i2c->dev, "failed to add MFD devices: %d\n", ret);
> - regmap_del_irq_chip(i2c->irq, axp20x->regmap_irqc);
> + dev_err(axp20x->dev, "failed to add MFD devices: %d\n", ret);
> + regmap_del_irq_chip(axp20x->irq, axp20x->regmap_irqc);
> return ret;
> }
>
> @@ -712,38 +665,25 @@ static int axp20x_i2c_probe(struct i2c_client *i2c,
> pm_power_off = axp20x_power_off;
> }
>
> - dev_info(&i2c->dev, "AXP20X driver loaded\n");
> + dev_info(axp20x->dev, "AXP20X driver loaded\n");
>
> return 0;
> }
> +EXPORT_SYMBOL(axp20x_device_probe);
>
> -static int axp20x_i2c_remove(struct i2c_client *i2c)
> +int axp20x_device_remove(struct axp20x_dev *axp20x)
> {
> - struct axp20x_dev *axp20x = i2c_get_clientdata(i2c);
> -
> if (axp20x == axp20x_pm_power_off) {
> axp20x_pm_power_off = NULL;
> pm_power_off = NULL;
> }
>
> mfd_remove_devices(axp20x->dev);
> - regmap_del_irq_chip(axp20x->i2c_client->irq, axp20x->regmap_irqc);
> + regmap_del_irq_chip(axp20x->irq, axp20x->regmap_irqc);
>
> return 0;
> }
> -
> -static struct i2c_driver axp20x_i2c_driver = {
> - .driver = {
> - .name = "axp20x",
> - .of_match_table = of_match_ptr(axp20x_of_match),
> - .acpi_match_table = ACPI_PTR(axp20x_acpi_match),
> - },
> - .probe = axp20x_i2c_probe,
> - .remove = axp20x_i2c_remove,
> - .id_table = axp20x_i2c_id,
> -};
> -
> -module_i2c_driver(axp20x_i2c_driver);
> +EXPORT_SYMBOL(axp20x_device_remove);
>
> MODULE_DESCRIPTION("PMIC MFD core driver for AXP20X");
> MODULE_AUTHOR("Carlo Caione <carlo@xxxxxxxxxx>");
> diff --git a/include/linux/mfd/axp20x.h b/include/linux/mfd/axp20x.h
> index b24c771cebd5..00697c6ad8b0 100644
> --- a/include/linux/mfd/axp20x.h
> +++ b/include/linux/mfd/axp20x.h
> @@ -396,7 +396,7 @@ enum axp288_irqs {
>
> struct axp20x_dev {
> struct device *dev;
> - struct i2c_client *i2c_client;
> + int irq;
> struct regmap *regmap;
> struct regmap_irq_chip_data *regmap_irqc;
> long variant;
> @@ -462,4 +462,35 @@ static inline int axp20x_read_variable_width(struct regmap *regmap,
> return result;
> }
>
> +/**
> + * axp20x_match_device(): Setup axp20x variant related fields
> + *
> + * @axp20x: axp20x device to setup (.dev field must be set)
> + * @dev: device associated with this axp20x device
> + *
> + * This lets the axp20x core configure the mfd cells and register maps
> + * for later use.
> + */
> +int axp20x_match_device(struct axp20x_dev *axp20x);
> +
> +/**
> + * axp20x_device_probe(): Probe a configured axp20x device
> + *
> + * @axp20x: axp20x device to probe (must be configured)
> + *
> + * This function lets the axp20x core register the axp20x mfd devices
> + * and irqchip. The axp20x device passed in must be fully configured
> + * with axp20x_match_device, its irq set, and regmap created.
> + */
> +int axp20x_device_probe(struct axp20x_dev *axp20x);
> +
> +/**
> + * axp20x_device_probe(): Remove a axp20x device
> + *
> + * @axp20x: axp20x device to remove
> + *
> + * This tells the axp20x core to remove the associated mfd devices
> + */
> +int axp20x_device_remove(struct axp20x_dev *axp20x);
> +
> #endif /* __LINUX_MFD_AXP20X_H */

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog