Re: [PATCH 1/6] mfd: max77843: Add max77843 MFD driver core driver

From: Beomho Seo
Date: Fri Jan 23 2015 - 06:26:56 EST

On 01/23/2015 08:18 PM, Krzysztof Kozlowski wrote:
> On piÄ, 2015-01-23 at 20:10 +0900, Beomho Seo wrote:
>> On 01/23/2015 04:16 PM, Krzysztof Kozlowski wrote:
>>> On piÄ, 2015-01-23 at 15:41 +0900, Beomho Seo wrote:
>>>> On 01/23/2015 03:32 PM, Krzysztof Kozlowski wrote:
>>>>> 2015-01-23 6:02 GMT+01:00 Jaewon Kim <jaewon02.kim@xxxxxxxxxxx>:
>>>>>> This patch adds MAX77843 core/irq driver to support PMIC,
>>>>>> MUIC(Micro USB Interface Controller), Charger, Fuel Gauge,
>>>>>> LED and Haptic device.
>>>>>>
>>>>>> Cc: Lee Jones <lee.jones@xxxxxxxxxx>
>>>>>> Signed-off-by: Beomho Seo <beomho.seo@xxxxxxxxxxx>
>>>>>> Signed-off-by: Jaewon Kim <jaewon02.kim@xxxxxxxxxxx>
>>>>>> ---
>>>>>> drivers/mfd/Kconfig | 14 ++
>>>>>> drivers/mfd/Makefile | 1 +
>>>>>> drivers/mfd/max77843.c | 241 ++++++++++++++++++++
>>>>>> include/linux/mfd/max77843-private.h | 410 ++++++++++++++++++++++++++++++++++
>>>>>> 4 files changed, 666 insertions(+)
>>>>>> create mode 100644 drivers/mfd/max77843.c
>>>>>> create mode 100644 include/linux/mfd/max77843-private.h
>>>>>>
>>>>>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>>>>>> index 2e6b731..0c67c79 100644
>>>>>> --- a/drivers/mfd/Kconfig
>>>>>> +++ b/drivers/mfd/Kconfig
>>>>>> @@ -442,6 +442,20 @@ config MFD_MAX77693
>>>>>> additional drivers must be enabled in order to use the functionality
>>>>>> of the device.
>>>>>>
>>>>>> +config MFD_MAX77843
>>>>>> + bool "Maxim Semiconductor MAX77843 PMIC Support"
>>>>>> + depends on I2C=y
>>>>>> + select MFD_CORE
>>>>>> + select REGMAP_I2C
>>>>>> + select REGMAP_IRQ
>>>>>> + help
>>>>>> + Say yes here to add support for Maxim Semiconductor MAX77843.
>>>>>> + This is companion Power Management IC with LEDs, Haptic, Charger,
>>>>>> + Fuel Gauge, MUIC(Micro USB Interface Controller) controls on chip.
>>>>>> + This driver provides common support for accessing the device;
>>>>>> + additional drivers must be enabled in order to use the functionality
>>>>>> + of the device.
>>>>>> +
>>>>>> config MFD_MAX8907
>>>>>> tristate "Maxim Semiconductor MAX8907 PMIC Support"
>>>>>> select MFD_CORE
>>>>>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>>>>>> index 53467e2..fe4f75c 100644
>>>>>> --- a/drivers/mfd/Makefile
>>>>>> +++ b/drivers/mfd/Makefile
>>>>>> @@ -117,6 +117,7 @@ obj-$(CONFIG_MFD_DA9063) += da9063.o
>>>>>> obj-$(CONFIG_MFD_MAX14577) += max14577.o
>>>>>> obj-$(CONFIG_MFD_MAX77686) += max77686.o
>>>>>> obj-$(CONFIG_MFD_MAX77693) += max77693.o
>>>>>> +obj-$(CONFIG_MFD_MAX77843) += max77843.o
>>>>>> obj-$(CONFIG_MFD_MAX8907) += max8907.o
>>>>>> max8925-objs := max8925-core.o max8925-i2c.o
>>>>>> obj-$(CONFIG_MFD_MAX8925) += max8925.o
>>>>>> diff --git a/drivers/mfd/max77843.c b/drivers/mfd/max77843.c
>>>>>> new file mode 100644
>>>>>> index 0000000..d7f8b76
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/mfd/max77843.c
>>>>>> @@ -0,0 +1,241 @@
>>>>>> +/*
>>>>>> + * max77843.c - MFD core driver for the Maxim MAX77843
>>>>>> + *
>>>>>> + * Copyright (C) 2014 Samsung Electrnoics
>>>>>> + * Author: Jaewon Kim <jaewon02.kim@xxxxxxxxxxx>
>>>>>> + *
>>>>>> + * This program is free software; you can redistribute it and/or modify
>>>>>> + * it under the terms of the GNU General Public License as published by
>>>>>> + * the Free Software Foundation; either version 2 of the License, or
>>>>>> + * (at your option) any later version.
>>>>>> + */
>>>>>> +
>>>>>> +#include <linux/err.h>
>>>>>> +#include <linux/i2c.h>
>>>>>> +#include <linux/init.h>
>>>>>> +#include <linux/interrupt.h>
>>>>>> +#include <linux/module.h>
>>>>>> +#include <linux/mfd/core.h>
>>>>>> +#include <linux/mfd/max77843-private.h>
>>>>>> +#include <linux/of_device.h>
>>>>>> +#include <linux/platform_device.h>
>>>>>> +
>>>>>> +static const struct mfd_cell max77843_devs[] = {
>>>>>> + {
>>>>>> + .name = "max77843-muic",
>>>>>> + .of_compatible = "maxim,max77843-muic",
>>>>>> + }, {
>>>>>> + .name = "max77843-regulator",
>>>>>> + .of_compatible = "maxim,max77843-regulator",
>>>>>> + }, {
>>>>>> + .name = "max77843-charger",
>>>>>> + .of_compatible = "maxim,max77843-charger"
>>>>>> + }, {
>>>>>> + .name = "max77843-fuelgauge",
>>>>>> + .of_compatible = "maxim,max77843-fuelgauge",
>>>>>> + },
>>>>>> +};
>>>>>> +
>>>>>> +static const struct regmap_config max77843_charger_regmap_config = {
>>>>>> + .reg_bits = 8,
>>>>>> + .val_bits = 8,
>>>>>> + .max_register = MAX77843_CHG_REG_END,
>>>>>> +};
>>>>>> +
>>>>>> +static const struct regmap_config max77843_regmap_config = {
>>>>>> + .reg_bits = 8,
>>>>>> + .val_bits = 8,
>>>>>> + .max_register = MAX77843_SYS_REG_END,
>>>>>> +};
>>>>>> +
>>>>>> +static const struct regmap_irq max77843_irqs[] = {
>>>>>> + /* TOPSYS interrupts */
>>>>>> + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_SYSUVLO_INT, },
>>>>>> + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_SYSOVLO_INT, },
>>>>>> + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_TSHDN_INT, },
>>>>>> + { .reg_offset = 0, .mask = MAX77843_SYS_IRQ_TM_INT, },
>>>>>> +};
>>>>>> +
>>>>>> +static const struct regmap_irq_chip max77843_irq_chip = {
>>>>>> + .name = "max77843",
>>>>>> + .status_base = MAX77843_SYS_REG_SYSINTSRC,
>>>>>> + .mask_base = MAX77843_SYS_REG_SYSINTMASK,
>>>>>> + .mask_invert = false,
>>>>>> + .num_regs = 1,
>>>>>> + .irqs = max77843_irqs,
>>>>>> + .num_irqs = ARRAY_SIZE(max77843_irqs),
>>>>>> +};
>>>>>> +
>>>>>> +static int max77843_chg_init(struct max77843 *max77843)
>>>>>> +{
>>>>>
>>>>> Could this function be moved to the charger driver? This way the
>>>>> driver will manage its own resources instead of depending on parent
>>>>> MFD driver.
>>>>>
>>>>
>>>> Charger regulator and Charger share same resources.
>>>> So I include this function core driver.
>>>
>>> OK, I see... Could you describe it in comments somewhere? For example in
>>> comment above the function. Currently this looks like only as regmap for
>>> charger.
>>>
>>
>> Charger regulator and Charger use same regmap.
>
> OK, just put it in a comment around that function.
>

OK, I add comment above max77843_chg_init function.

>>
>>> Unfortunately current solution imposes problem with releasing resources.
>>> Who is the owner of i2c dummy device?
>>>
>>
>> Core driver owner of i2c dummy device.
>
> OK, good idea. So the core driver should be the only place to unregister
> it. So needed changes are:
> 1. Remove the i2c_unregister_device() call from
> max77843_charger_probe().
> 2. Add i2c_unregister_device(max77843->i2c_chg) in max77843_remove().
>
> The MFD core driver will handle it.
>

It will be fixed comply with your advice.

>>
>>> 1. The charger driver will unregister it if max77843_charger_probe()
>>> fails. What will happen with regulator driver in such case?
>>>
>>
>> Charger is enabled/disabled by Charger regulator.
>> Currently, If charger probe fails, charger regulator failed to read regmap and occur panic(It have to fix.)
>>
>>
>>> 2. Who will release this i2c dummy device in normal unbind? Currently it
>>> leaks.
>>>
>>
>> I think core driver release i2c dummy device in normal unbind.
>> We need to more discussion about this problem.
>> If you have any idea, I hope tell me. Again, Thank you for your advice.
>
> I think handling the ownership in core driver could solve this.
>
> Best regards,
> Krzysztof
>

OK. I will fix it.

Thanks,
Beomho

>
>
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