linux-kernel - Re: [PATCH v3 2/2] mfd: rohm-bd71828: Add power off functionality

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Message-ID: <20240411140750.GA2399047@google.com>
Date: Thu, 11 Apr 2024 15:07:50 +0100
From: Lee Jones <lee@...nel.org>
To: Matti Vaittinen <mazziesaccount@...il.com>
Cc: Andreas Kemnade <andreas@...nade.info>, robh+dt@...nel.org,
	krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/2] mfd: rohm-bd71828: Add power off functionality

On Thu, 11 Apr 2024, Matti Vaittinen wrote:

> On 4/11/24 14:50, Lee Jones wrote:
> > On Tue, 02 Apr 2024, Andreas Kemnade wrote:
> > 
> > > Since the chip can power off the system, add the corresponding
> > > functionality.
> > > Based on https://github.com/kobolabs/Kobo-Reader/raw/master/hw/imx6sll-clara2e/kernel.tar.bz2
> > > 
> > > Signed-off-by: Andreas Kemnade <andreas@...nade.info>
> > > Acked-by: Matti Vaittinen <mazziesaccount@...il.com>
> > > ---
> > >   drivers/mfd/rohm-bd71828.c       | 36 +++++++++++++++++++++++++++++++-
> > >   include/linux/mfd/rohm-bd71828.h |  3 +++
> > >   2 files changed, 38 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/mfd/rohm-bd71828.c b/drivers/mfd/rohm-bd71828.c
> > > index 594718f7e8e1..4a1fa8a0d76a 100644
> > > --- a/drivers/mfd/rohm-bd71828.c
> > > +++ b/drivers/mfd/rohm-bd71828.c
> > > @@ -464,6 +464,27 @@ static int set_clk_mode(struct device *dev, struct regmap *regmap,
> > >   				  OUT32K_MODE_CMOS);
> > >   }
> > > +static struct i2c_client *bd71828_dev;
> > > +static void bd71828_power_off(void)
> > > +{
> > > +	while (true) {
> > > +		s32 val;
> > > +
> > > +		/* We are not allowed to sleep, so do not use regmap involving mutexes here. */
> > > +		val = i2c_smbus_read_byte_data(bd71828_dev, BD71828_REG_PS_CTRL_1);
> > > +		if (val >= 0)
> > > +			i2c_smbus_write_byte_data(bd71828_dev,
> > > +						  BD71828_REG_PS_CTRL_1,
> > > +						  BD71828_MASK_STATE_HBNT | (u8)val);
> > > +		mdelay(500);
> > > +	}
> > > +}
> > > +
> > > +static void bd71828_remove_poweroff(void *data)
> > > +{
> > > +	pm_power_off = NULL;
> > > +}
> > > +
> > >   static int bd71828_i2c_probe(struct i2c_client *i2c)
> > >   {
> > >   	struct regmap_irq_chip_data *irq_data;
> > > @@ -542,7 +563,20 @@ static int bd71828_i2c_probe(struct i2c_client *i2c)
> > >   	ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO, mfd, cells,
> > >   				   NULL, 0, regmap_irq_get_domain(irq_data));
> > >   	if (ret)
> > > -		dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
> > > +		return	dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
> > > +
> > > +	if (of_device_is_system_power_controller(i2c->dev.of_node) &&
> > > +	    chip_type == ROHM_CHIP_TYPE_BD71828) {
> > > +		if (!pm_power_off) {
> > > +			bd71828_dev = i2c;
> > > +			pm_power_off = bd71828_power_off;
> > > +			ret = devm_add_action_or_reset(&i2c->dev,
> > > +						       bd71828_remove_poweroff,
> > > +						       NULL);
> > > +		} else {
> > > +			dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
> > > +		}
> > > +	}
> > >   	return ret;
> > >   }
> > > diff --git a/include/linux/mfd/rohm-bd71828.h b/include/linux/mfd/rohm-bd71828.h
> > > index 3b5f3a7db4bd..9776fde1262d 100644
> > > --- a/include/linux/mfd/rohm-bd71828.h
> > > +++ b/include/linux/mfd/rohm-bd71828.h
> > > @@ -4,6 +4,7 @@
> > >   #ifndef __LINUX_MFD_BD71828_H__
> > >   #define __LINUX_MFD_BD71828_H__
> > > +#include <linux/bits.h>
> > >   #include <linux/mfd/rohm-generic.h>
> > >   #include <linux/mfd/rohm-shared.h>
> > > @@ -41,6 +42,8 @@ enum {
> > >   #define BD71828_REG_PS_CTRL_2		0x05
> > >   #define BD71828_REG_PS_CTRL_3		0x06
> > > +#define BD71828_MASK_STATE_HBNT		BIT(1)
> > > +
> > >   //#define BD71828_REG_SWRESET		0x06
> > 
> > How did this get in here?
> 
> Don't blame me, blame git... Errm... :)
> [mvaittin@...ora linux]$ git blame include/linux/mfd/rohm-bd71828.h |grep
> \/\/
> 1c743ad523bb2 (Matti Vaittinen 2020-01-20 15:43:28 +0200  44) //#define
> BD71828_REG_SWRESET		0x06
> 1c743ad523bb2 (Matti Vaittinen 2020-01-20 15:43:28 +0200 136) //#define
> BD71828_REG_LDO6_VOLT		0x4
> 
> I can send a clean-up patch unless you want to do it while applying other
> stuff...

Please submit a patch.

-- 
Lee Jones [李琼斯]