Re: [PATCH v2 2/2] power: supply: bq27xxx: move platform driver code into bq27xxx_battery_hdq.c

From: Sebastian Reichel
Date: Tue Jul 25 2017 - 09:43:11 EST


Hi,

On Wed, Jul 19, 2017 at 12:04:07PM -0500, Andrew F. Davis wrote:
> When the BQ27xxx driver was originally written the w1 subsystem only
> allowed device drivers for w1 attached devices to live in the w1
> subsystem. Kernel driver subsystems expect that the driver for a device
> live in the directory of the subsystem for which it implements
> functionality, not in the directory of the bus that it is attached. To
> work around this, the BQ27xxx driver was implemented as a platform device
> driver and the interface driver would instantiate this device from within
> the w1 directory, then pass a w1 read callback as platform data.
>
> As we can now have the w1 interface driver in the power/supply directory
> (like we do already with the i2c interface driver) we can remove this
> middle-layer platform driver.
>
> Signed-off-by: Andrew F. Davis <afd@xxxxxx>
> Acked-by: Pali Rohár <pali.rohar@xxxxxxxxx>
> Acked-by: Sebastian Reichel <sre@xxxxxxxxxx>

Thanks, queued to power-supply's for-next branch.

-- Sebastian

> drivers/power/supply/bq27xxx_battery.c | 104 ------------
> drivers/power/supply/bq27xxx_battery_hdq.c | 250 ++++++++++++++++-------------
> include/linux/power/bq27xxx_battery.h | 17 --
> 3 files changed, 135 insertions(+), 236 deletions(-)
> rewrite drivers/power/supply/bq27xxx_battery_hdq.c (72%)
>
> diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c
> index ed44439d0112..079083b31293 100644
> --- a/drivers/power/supply/bq27xxx_battery.c
> +++ b/drivers/power/supply/bq27xxx_battery.c
> @@ -1938,110 +1938,6 @@ void bq27xxx_battery_teardown(struct bq27xxx_device_info *di)
> }
> EXPORT_SYMBOL_GPL(bq27xxx_battery_teardown);
>
> -static int bq27xxx_battery_platform_read(struct bq27xxx_device_info *di, u8 reg,
> - bool single)
> -{
> - struct device *dev = di->dev;
> - struct bq27xxx_platform_data *pdata = dev->platform_data;
> - unsigned int timeout = 3;
> - int upper, lower;
> - int temp;
> -
> - if (!single) {
> - /* Make sure the value has not changed in between reading the
> - * lower and the upper part */
> - upper = pdata->read(dev, reg + 1);
> - do {
> - temp = upper;
> - if (upper < 0)
> - return upper;
> -
> - lower = pdata->read(dev, reg);
> - if (lower < 0)
> - return lower;
> -
> - upper = pdata->read(dev, reg + 1);
> - } while (temp != upper && --timeout);
> -
> - if (timeout == 0)
> - return -EIO;
> -
> - return (upper << 8) | lower;
> - }
> -
> - return pdata->read(dev, reg);
> -}
> -
> -static int bq27xxx_battery_platform_probe(struct platform_device *pdev)
> -{
> - struct bq27xxx_device_info *di;
> - struct bq27xxx_platform_data *pdata = pdev->dev.platform_data;
> -
> - if (!pdata) {
> - dev_err(&pdev->dev, "no platform_data supplied\n");
> - return -EINVAL;
> - }
> -
> - if (!pdata->read) {
> - dev_err(&pdev->dev, "no hdq read callback supplied\n");
> - return -EINVAL;
> - }
> -
> - if (!pdata->chip) {
> - dev_err(&pdev->dev, "no device supplied\n");
> - return -EINVAL;
> - }
> -
> - di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
> - if (!di)
> - return -ENOMEM;
> -
> - platform_set_drvdata(pdev, di);
> -
> - di->dev = &pdev->dev;
> - di->chip = pdata->chip;
> - di->name = pdata->name ?: dev_name(&pdev->dev);
> - di->bus.read = bq27xxx_battery_platform_read;
> -
> - return bq27xxx_battery_setup(di);
> -}
> -
> -static int bq27xxx_battery_platform_remove(struct platform_device *pdev)
> -{
> - struct bq27xxx_device_info *di = platform_get_drvdata(pdev);
> -
> - bq27xxx_battery_teardown(di);
> -
> - return 0;
> -}
> -
> -static const struct platform_device_id bq27xxx_battery_platform_id_table[] = {
> - { "bq27000-battery", },
> - { /* sentinel */ }
> -};
> -MODULE_DEVICE_TABLE(platform, bq27xxx_battery_platform_id_table);
> -
> -#ifdef CONFIG_OF
> -static const struct of_device_id bq27xxx_battery_platform_of_match_table[] = {
> - { .compatible = "ti,bq27000" },
> - {},
> -};
> -MODULE_DEVICE_TABLE(of, bq27xxx_battery_platform_of_match_table);
> -#endif
> -
> -static struct platform_driver bq27xxx_battery_platform_driver = {
> - .probe = bq27xxx_battery_platform_probe,
> - .remove = bq27xxx_battery_platform_remove,
> - .driver = {
> - .name = "bq27000-battery",
> - .of_match_table = of_match_ptr(bq27xxx_battery_platform_of_match_table),
> - },
> - .id_table = bq27xxx_battery_platform_id_table,
> -};
> -module_platform_driver(bq27xxx_battery_platform_driver);
> -
> -MODULE_ALIAS("platform:bq27000-battery");
> -
> MODULE_AUTHOR("Rodolfo Giometti <giometti@xxxxxxxx>");
> MODULE_DESCRIPTION("BQ27xxx battery monitor driver");
> MODULE_LICENSE("GPL");
> diff --git a/drivers/power/supply/bq27xxx_battery_hdq.c b/drivers/power/supply/bq27xxx_battery_hdq.c
> dissimilarity index 72%
> index f4df67eb9d2c..9aff896c9802 100644
> --- a/drivers/power/supply/bq27xxx_battery_hdq.c
> +++ b/drivers/power/supply/bq27xxx_battery_hdq.c
> @@ -1,115 +1,135 @@
> -/*
> - * Copyright (C) 2007 Texas Instruments, Inc.
> - *
> - * This file is licensed under the terms of the GNU General Public License
> - * version 2. This program is licensed "as is" without any warranty of any
> - * kind, whether express or implied.
> - *
> - */
> -
> -#include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <linux/device.h>
> -#include <linux/types.h>
> -#include <linux/platform_device.h>
> -#include <linux/mutex.h>
> -#include <linux/power/bq27xxx_battery.h>
> -
> -#include <linux/w1.h>
> -
> -#define W1_FAMILY_BQ27000 0x01
> -
> -#define HDQ_CMD_READ (0)
> -#define HDQ_CMD_WRITE (1<<7)
> -
> -static int F_ID;
> -module_param(F_ID, int, S_IRUSR);
> -MODULE_PARM_DESC(F_ID, "1-wire slave FID for BQ device");
> -
> -static int w1_bq27000_read(struct device *dev, unsigned int reg)
> -{
> - u8 val;
> - struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
> -
> - mutex_lock(&sl->master->bus_mutex);
> - w1_write_8(sl->master, HDQ_CMD_READ | reg);
> - val = w1_read_8(sl->master);
> - mutex_unlock(&sl->master->bus_mutex);
> -
> - return val;
> -}
> -
> -static struct bq27xxx_platform_data bq27000_battery_info = {
> - .read = w1_bq27000_read,
> - .name = "bq27000-battery",
> - .chip = BQ27000,
> -};
> -
> -static int w1_bq27000_add_slave(struct w1_slave *sl)
> -{
> - int ret;
> - struct platform_device *pdev;
> -
> - pdev = platform_device_alloc("bq27000-battery", -1);
> - if (!pdev) {
> - ret = -ENOMEM;
> - return ret;
> - }
> - ret = platform_device_add_data(pdev,
> - &bq27000_battery_info,
> - sizeof(bq27000_battery_info));
> - if (ret)
> - goto pdev_add_failed;
> - pdev->dev.parent = &sl->dev;
> -
> - ret = platform_device_add(pdev);
> - if (ret)
> - goto pdev_add_failed;
> -
> - dev_set_drvdata(&sl->dev, pdev);
> -
> - goto success;
> -
> -pdev_add_failed:
> - platform_device_put(pdev);
> -success:
> - return ret;
> -}
> -
> -static void w1_bq27000_remove_slave(struct w1_slave *sl)
> -{
> - struct platform_device *pdev = dev_get_drvdata(&sl->dev);
> -
> - platform_device_unregister(pdev);
> -}
> -
> -static struct w1_family_ops w1_bq27000_fops = {
> - .add_slave = w1_bq27000_add_slave,
> - .remove_slave = w1_bq27000_remove_slave,
> -};
> -
> -static struct w1_family w1_bq27000_family = {
> - .fid = W1_FAMILY_BQ27000,
> - .fops = &w1_bq27000_fops,
> -};
> -
> -static int __init w1_bq27000_init(void)
> -{
> - if (F_ID)
> - w1_bq27000_family.fid = F_ID;
> -
> - return w1_register_family(&w1_bq27000_family);
> -}
> -
> -static void __exit w1_bq27000_exit(void)
> -{
> - w1_unregister_family(&w1_bq27000_family);
> -}
> -
> -module_init(w1_bq27000_init);
> -module_exit(w1_bq27000_exit);
> -
> -MODULE_AUTHOR("Texas Instruments Ltd");
> -MODULE_DESCRIPTION("HDQ/1-wire slave driver bq27000 battery monitor chip");
> -MODULE_LICENSE("GPL");
> -MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_BQ27000));
> +/*
> + * BQ27xxx battery monitor HDQ/1-wire driver
> + *
> + * Copyright (C) 2007-2017 Texas Instruments Incorporated - http://www.ti.com/
> + *
> + * 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.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/types.h>
> +#include <linux/platform_device.h>
> +#include <linux/mutex.h>
> +#include <linux/power/bq27xxx_battery.h>
> +
> +#include <linux/w1.h>
> +
> +#define W1_FAMILY_BQ27000 0x01
> +
> +#define HDQ_CMD_READ (0 << 7)
> +#define HDQ_CMD_WRITE (1 << 7)
> +
> +static int F_ID;
> +module_param(F_ID, int, S_IRUSR);
> +MODULE_PARM_DESC(F_ID, "1-wire slave FID for BQ27xxx device");
> +
> +static int w1_bq27000_read(struct w1_slave *sl, unsigned int reg)
> +{
> + u8 val;
> +
> + mutex_lock(&sl->master->bus_mutex);
> + w1_write_8(sl->master, HDQ_CMD_READ | reg);
> + val = w1_read_8(sl->master);
> + mutex_unlock(&sl->master->bus_mutex);
> +
> + return val;
> +}
> +
> +static int bq27xxx_battery_hdq_read(struct bq27xxx_device_info *di, u8 reg,
> + bool single)
> +{
> + struct w1_slave *sl = dev_to_w1_slave(di->dev);
> + unsigned int timeout = 3;
> + int upper, lower;
> + int temp;
> +
> + if (!single) {
> + /*
> + * Make sure the value has not changed in between reading the
> + * lower and the upper part
> + */
> + upper = w1_bq27000_read(sl, reg + 1);
> + do {
> + temp = upper;
> + if (upper < 0)
> + return upper;
> +
> + lower = w1_bq27000_read(sl, reg);
> + if (lower < 0)
> + return lower;
> +
> + upper = w1_bq27000_read(sl, reg + 1);
> + } while (temp != upper && --timeout);
> +
> + if (timeout == 0)
> + return -EIO;
> +
> + return (upper << 8) | lower;
> + }
> +
> + return w1_bq27000_read(sl, reg);
> +}
> +
> +static int bq27xxx_battery_hdq_add_slave(struct w1_slave *sl)
> +{
> + struct bq27xxx_device_info *di;
> +
> + di = devm_kzalloc(&sl->dev, sizeof(*di), GFP_KERNEL);
> + if (!di)
> + return -ENOMEM;
> +
> + dev_set_drvdata(&sl->dev, di);
> +
> + di->dev = &sl->dev;
> + di->chip = BQ27000;
> + di->name = "bq27000-battery";
> + di->bus.read = bq27xxx_battery_hdq_read;
> +
> + return bq27xxx_battery_setup(di);
> +}
> +
> +static void bq27xxx_battery_hdq_remove_slave(struct w1_slave *sl)
> +{
> + struct bq27xxx_device_info *di = dev_get_drvdata(&sl->dev);
> +
> + bq27xxx_battery_teardown(di);
> +}
> +
> +static struct w1_family_ops bq27xxx_battery_hdq_fops = {
> + .add_slave = bq27xxx_battery_hdq_add_slave,
> + .remove_slave = bq27xxx_battery_hdq_remove_slave,
> +};
> +
> +static struct w1_family bq27xxx_battery_hdq_family = {
> + .fid = W1_FAMILY_BQ27000,
> + .fops = &bq27xxx_battery_hdq_fops,
> +};
> +
> +static int __init bq27xxx_battery_hdq_init(void)
> +{
> + if (F_ID)
> + bq27xxx_battery_hdq_family.fid = F_ID;
> +
> + return w1_register_family(&bq27xxx_battery_hdq_family);
> +}
> +module_init(bq27xxx_battery_hdq_init);
> +
> +static void __exit bq27xxx_battery_hdq_exit(void)
> +{
> + w1_unregister_family(&bq27xxx_battery_hdq_family);
> +}
> +module_exit(bq27xxx_battery_hdq_exit);
> +
> +MODULE_AUTHOR("Texas Instruments Ltd");
> +MODULE_DESCRIPTION("BQ27xxx battery monitor HDQ/1-wire driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_BQ27000));
> diff --git a/include/linux/power/bq27xxx_battery.h b/include/linux/power/bq27xxx_battery.h
> index 11e11685dd1d..89890437f9ab 100644
> --- a/include/linux/power/bq27xxx_battery.h
> +++ b/include/linux/power/bq27xxx_battery.h
> @@ -20,23 +20,6 @@ enum bq27xxx_chip {
> BQ27421, /* bq27421, bq27425, bq27441, bq27621 */
> };
>
> -/**
> - * struct bq27xxx_plaform_data - Platform data for bq27xxx devices
> - * @name: Name of the battery.
> - * @chip: Chip class number of this device.
> - * @read: HDQ read callback.
> - * This function should provide access to the HDQ bus the battery is
> - * connected to.
> - * The first parameter is a pointer to the battery device, the second the
> - * register to be read. The return value should either be the content of
> - * the passed register or an error value.
> - */
> -struct bq27xxx_platform_data {
> - const char *name;
> - enum bq27xxx_chip chip;
> - int (*read)(struct device *dev, unsigned int);
> -};
> -
> struct bq27xxx_device_info;
> struct bq27xxx_access_methods {
> int (*read)(struct bq27xxx_device_info *di, u8 reg, bool single);
> --
> 2.13.0
>

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