Re: [PATCH v2] Add regulator driver for the bq2407x family of charger ICs.

[MyungJoo Ham <myungjoo.ham@gmail.com>]

On Thu, Aug 25, 2011 at 3:48 AM, Heiko Stübner <heiko@sntech.de> wrote:
> This driver controls a TI bq2407x charger attached via GPIOs.
> The provided current regulator can enable/disable charging and
> select between 100 mA, 500 mA and a machine specific current limit.
>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
>

Hello,

This looks like a bq24022 driver + max-current-mode ("USB standby"
seems not implemented in the driver). Wouldn't it be possible to patch
bq24022 driver so that the bq24022 driver becomes compatible with this
bq2407x?

2407x's EN1 = 24022's iset2
2407x's nce = 24022's nce

I think you may simply let the driver ignore EN2 (and max-current
mode) if the supplied EN2 in pdata is NULL, then, the driver will be
compatible for both.

Cheers,
MyungJoo

> ---
> Changes since v1:
>  - add private struct to keep track of gpio states
>  - get max_uA from regulator_init_data
>   (no need to define it twice)
>  - disallow setting current limix below 100mA
>
>  drivers/regulator/Kconfig         |    8 +
>  drivers/regulator/Makefile        |    1 +
>  drivers/regulator/bq2407x.c       |  264 +++++++++++++++++++++++++++++++++++++
>  include/linux/regulator/bq2407x.h |   35 +++++
>  4 files changed, 308 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
> index c7fd2c0..921e271 100644
> --- a/drivers/regulator/Kconfig
> +++ b/drivers/regulator/Kconfig
> @@ -72,6 +72,14 @@ config REGULATOR_BQ24022
>          charging select between 100 mA and 500 mA charging current
>          limit.
>
> +config REGULATOR_BQ2407x
> +       tristate "TI bq2407x Li-Ion Charger IC"
> +       help
> +         This driver controls a TI bq2407x Charger attached via
> +         GPIOs. The provided current regulator can enable/disable
> +         charging select between 100 mA, 500 mA and a machine specific
> +         charging current limit.
> +
>  config REGULATOR_MAX1586
>        tristate "Maxim 1586/1587 voltage regulator"
>        depends on I2C
> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
> index 040d5aa..ce65493 100644
> --- a/drivers/regulator/Makefile
> +++ b/drivers/regulator/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o
>
>  obj-$(CONFIG_REGULATOR_AD5398) += ad5398.o
>  obj-$(CONFIG_REGULATOR_BQ24022) += bq24022.o
> +obj-$(CONFIG_REGULATOR_BQ2407x) += bq2407x.o
>  obj-$(CONFIG_REGULATOR_LP3971) += lp3971.o
>  obj-$(CONFIG_REGULATOR_LP3972) += lp3972.o
>  obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
> diff --git a/drivers/regulator/bq2407x.c b/drivers/regulator/bq2407x.c
> new file mode 100644
> index 0000000..a8221d5
> --- /dev/null
> +++ b/drivers/regulator/bq2407x.c
> @@ -0,0 +1,264 @@
> +/*
> + * Support for TI bq2407x USB-friendly
> + * Li-Ion Charger connected via GPIOs.
> + *
> + * Copyright (c) 2011 Heiko Stuebner
> + *
> + * based on the bq24022 driver
> + * Copyright (c) 2008 Philipp Zabel
> + *
> + * 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/kernel.h>
> +#include <linux/init.h>
> +#include <linux/platform_device.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/gpio.h>
> +#include <linux/regulator/bq2407x.h>
> +#include <linux/regulator/driver.h>
> +#include <linux/regulator/machine.h>
> +
> +struct bq2407x {
> +       struct regulator_dev    *rdev;
> +
> +       int gpio_nce;
> +       int gpio_en2;
> +       int gpio_en1;
> +
> +       int state_nce;
> +       int state_en2;
> +       int state_en1;
> +
> +       int max_uA;
> +};
> +
> +
> +static int bq2407x_set_current_limit(struct regulator_dev *rdev,
> +                                       int min_uA, int max_uA)
> +{
> +       struct bq2407x *bq = rdev_get_drvdata(rdev);
> +
> +       if (bq->max_uA && bq->max_uA > 500000
> +                             && max_uA >= bq->max_uA) {
> +               dev_dbg(rdev_get_dev(rdev),
> +                       "setting current limit to %d mA\n",
> +                       bq->max_uA / 1000);
> +               gpio_set_value(bq->gpio_en2, 1);
> +               bq->state_en2 = 1;
> +               gpio_set_value(bq->gpio_en1, 0);
> +               bq->state_en1 = 0;
> +       } else if (max_uA >= 500000) {
> +               dev_dbg(rdev_get_dev(rdev),
> +                       "setting current limit to 500 mA\n");
> +               gpio_set_value(bq->gpio_en2, 0);
> +               bq->state_en2 = 0;
> +               gpio_set_value(bq->gpio_en1, 1);
> +               bq->state_en1 = 1;
> +       } else if (max_uA >= 100000) {
> +               dev_dbg(rdev_get_dev(rdev),
> +                       "setting current limit to 100 mA\n");
> +               gpio_set_value(bq->gpio_en2, 0);
> +               bq->state_en2 = 0;
> +               gpio_set_value(bq->gpio_en1, 0);
> +               bq->state_en1 = 0;
> +       } else {
> +               dev_err(rdev_get_dev(rdev), "cannot set current limit below 100 mA\n");
> +               return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
> +static int bq2407x_get_current_limit(struct regulator_dev *rdev)
> +{
> +       struct bq2407x *bq = rdev_get_drvdata(rdev);
> +
> +       if (bq->state_en2 && bq->state_en1)
> +               return 0;
> +       else if (bq->state_en2 && !bq->state_en1)
> +               return bq->max_uA;
> +       else if (!bq->state_en2 && bq->state_en1)
> +               return 500000;
> +       else
> +               return 100000;
> +}
> +
> +static int bq2407x_enable(struct regulator_dev *rdev)
> +{
> +       struct bq2407x *bq = rdev_get_drvdata(rdev);
> +
> +       dev_dbg(rdev_get_dev(rdev), "enabling charger\n");
> +
> +       gpio_set_value(bq->gpio_nce, 0);
> +       bq->state_nce = 0;
> +
> +       return 0;
> +}
> +
> +static int bq2407x_disable(struct regulator_dev *rdev)
> +{
> +       struct bq2407x *bq = rdev_get_drvdata(rdev);
> +
> +       dev_dbg(rdev_get_dev(rdev), "disabling charger\n");
> +
> +       gpio_set_value(bq->gpio_nce, 1);
> +       bq->state_nce = 1;
> +
> +       return 0;
> +}
> +
> +static int bq2407x_is_enabled(struct regulator_dev *rdev)
> +{
> +       struct bq2407x *bq = rdev_get_drvdata(rdev);
> +
> +       return !bq->state_nce;
> +}
> +
> +static struct regulator_ops bq2407x_ops = {
> +       .set_current_limit = bq2407x_set_current_limit,
> +       .get_current_limit = bq2407x_get_current_limit,
> +       .enable            = bq2407x_enable,
> +       .disable           = bq2407x_disable,
> +       .is_enabled        = bq2407x_is_enabled,
> +};
> +
> +static struct regulator_desc bq2407x_desc = {
> +       .name  = "bq2407x",
> +       .ops   = &bq2407x_ops,
> +       .type  = REGULATOR_CURRENT,
> +       .owner = THIS_MODULE,
> +};
> +
> +static int __init bq2407x_probe(struct platform_device *pdev)
> +{
> +       struct bq2407x_mach_info *pdata = pdev->dev.platform_data;
> +       struct bq2407x *bq;
> +       int ret;
> +
> +       if (!pdata || !pdata->gpio_nce || !pdata->gpio_en1 || !pdata->gpio_en2)
> +               return -EINVAL;
> +
> +       bq = kzalloc(sizeof(struct bq2407x), GFP_KERNEL);
> +       if (!bq) {
> +               dev_err(&pdev->dev, "cannot allocate memory\n");
> +               return -ENOMEM;
> +       }
> +
> +       ret = gpio_request(pdata->gpio_nce, "ncharge_en");
> +       if (ret) {
> +               dev_dbg(&pdev->dev, "couldn't request nCE GPIO: %d\n",
> +                       pdata->gpio_nce);
> +               goto err_ce;
> +       }
> +       ret = gpio_request(pdata->gpio_en2, "charge_mode_en2");
> +       if (ret) {
> +               dev_dbg(&pdev->dev, "couldn't request EN2 GPIO: %d\n",
> +                       pdata->gpio_en2);
> +               goto err_en2;
> +       }
> +       ret = gpio_request(pdata->gpio_en1, "charge_mode_en1");
> +       if (ret) {
> +               dev_dbg(&pdev->dev, "couldn't request EN1 GPIO: %d\n",
> +                       pdata->gpio_en1);
> +               goto err_en1;
> +       }
> +
> +       /* set initial current to 100mA and disable regulator */
> +       ret = gpio_direction_output(pdata->gpio_en2, 0);
> +       if (ret) {
> +               dev_dbg(&pdev->dev, "couldn't set EN2 GPIO: %d\n",
> +                       pdata->gpio_en1);
> +               goto err_reg;
> +       }
> +       bq->gpio_en2  = pdata->gpio_en2;
> +       bq->state_en2 = 0;
> +       ret = gpio_direction_output(pdata->gpio_en1, 0);
> +       if (ret) {
> +               dev_dbg(&pdev->dev, "couldn't set EN1 GPIO: %d\n",
> +                       pdata->gpio_en1);
> +               goto err_reg;
> +       }
> +       bq->gpio_en1  = pdata->gpio_en1;
> +       bq->state_en1 = 0;
> +       ret = gpio_direction_output(pdata->gpio_nce, 1);
> +       if (ret) {
> +               dev_dbg(&pdev->dev, "couldn't set nCE GPIO: %d\n",
> +                       pdata->gpio_en1);
> +               goto err_reg;
> +       }
> +       bq->gpio_nce  = pdata->gpio_nce;
> +       bq->state_nce = 1;
> +
> +       /* get maximum current from regulator_init_data */
> +       if (pdata->init_data) {
> +               bq->max_uA = pdata->init_data->constraints.max_uA;
> +               dev_dbg(&pdev->dev, "maximum current is %d mA\n",
> +                       bq->max_uA / 1000);
> +       }
> +
> +       bq->rdev = regulator_register(&bq2407x_desc, &pdev->dev,
> +                                       pdata->init_data, bq);
> +       if (IS_ERR(bq->rdev)) {
> +               dev_dbg(&pdev->dev, "couldn't register regulator\n");
> +               ret = PTR_ERR(bq->rdev);
> +               goto err_reg;
> +       }
> +
> +       platform_set_drvdata(pdev, bq);
> +       dev_dbg(&pdev->dev, "registered regulator\n");
> +
> +       return 0;
> +err_reg:
> +       gpio_free(pdata->gpio_en1);
> +err_en1:
> +       gpio_free(pdata->gpio_en2);
> +err_en2:
> +       gpio_free(pdata->gpio_nce);
> +err_ce:
> +       kfree(bq);
> +       return ret;
> +}
> +
> +static int __devexit bq2407x_remove(struct platform_device *pdev)
> +{
> +       struct bq2407x *bq = platform_get_drvdata(pdev);
> +
> +       regulator_unregister(bq->rdev);
> +       gpio_free(bq->gpio_en1);
> +       gpio_free(bq->gpio_en2);
> +       gpio_free(bq->gpio_nce);
> +
> +       kfree(bq);
> +
> +       return 0;
> +}
> +
> +static struct platform_driver bq2407x_driver = {
> +       .driver = {
> +               .name = "bq2407x",
> +       },
> +       .remove = __devexit_p(bq2407x_remove),
> +};
> +
> +static int __init bq2407x_init(void)
> +{
> +       return platform_driver_probe(&bq2407x_driver, bq2407x_probe);
> +}
> +
> +static void __exit bq2407x_exit(void)
> +{
> +       platform_driver_unregister(&bq2407x_driver);
> +}
> +
> +module_init(bq2407x_init);
> +module_exit(bq2407x_exit);
> +
> +MODULE_AUTHOR("Heiko Stuebner");
> +MODULE_DESCRIPTION("TI bq2407x Li-Ion Charger driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/regulator/bq2407x.h b/include/linux/regulator/bq2407x.h
> new file mode 100644
> index 0000000..14d6d93
> --- /dev/null
> +++ b/include/linux/regulator/bq2407x.h
> @@ -0,0 +1,35 @@
> +/*
> + * Support for TI bq2407x 1.5A USB-friendly
> + * Li-Ion Charger connected via GPIOs.
> + *
> + * Copyright (c) 2011 Heiko Stuebner
> + *
> + * based on the bq24022 driver
> + * Copyright (c) 2008 Philipp Zabel
> + *
> + * 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.
> + *
> + */
> +
> +struct regulator_init_data;
> +
> +/**
> + * bq2407x_mach_info - platform data for bq2407x
> + * @gpio_nce: GPIO line connected to the nCE pin, used to control charging
> + * @gpio_en2: GPIO line connected to the EN2 pin, used to limit charging
> + * @gpio_en1: GPIO line connected to the EN1 pin, used to limit charging
> + * @max_uA: maximum current defined by resistor on ILIM connector
> + * Modes of operation:
> + * EN2 = 0, EN1 = 0: 100mA
> + * EN2 = 0, EN1 = 1: 500mA
> + * EN2 = 1, EN1 = 0: max_current
> + * EN2 = 1, EN1 = 1: Standby (usb suspend)
> + */
> +struct bq2407x_mach_info {
> +       int gpio_nce;
> +       int gpio_en2;
> +       int gpio_en1;
> +       struct regulator_init_data *init_data;
> +};
> --
> tg: (93ee7a9..) topic/drivers/bq2407x (depends on: master)
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-- 
MyungJoo Ham, Ph.D.
Mobile Software Platform Lab, DMC Business, Samsung Electronics