linux-kernel - Re: [PATCH 3/3] mfd: tps6594: Adds support for powering off the PMIC

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Message-ID: <20250613141105.GG897353@google.com>
Date: Fri, 13 Jun 2025 15:11:05 +0100
From: Lee Jones <lee@...nel.org>
To: Job Sava <jsava@...ticallink.com>
Cc: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Julien Panis <jpanis@...libre.com>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-input@...r.kernel.org, jcormier@...ticallink.com
Subject: Re: [PATCH 3/3] mfd: tps6594: Adds support for powering off the PMIC

On Tue, 20 May 2025, Job Sava wrote:

> When the FSM_I2C_TRIGGER register's bit 0 is set it triggers TRIGGER_I2C_0
> and the PMIC is transitioned to the STANDBY state
> (table 6-18: SLVSGG7 – DECEMBER 2023).
> 
> An ON request is required to transition from STANDBY to ACTIVE.
> 
> Signed-off-by: Job Sava <jsava@...ticallink.com>
> ---
>  drivers/mfd/tps6594-core.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/mfd/tps6594-core.c b/drivers/mfd/tps6594-core.c
> index 1b0b3d1bf6c4..f4c434c0d87a 100644
> --- a/drivers/mfd/tps6594-core.c
> +++ b/drivers/mfd/tps6594-core.c
> @@ -10,6 +10,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/reboot.h>
>  
>  #include <linux/mfd/core.h>
>  #include <linux/mfd/tps6594.h>
> @@ -615,6 +616,19 @@ static int tps6594_enable_crc(struct tps6594 *tps)
>  	return ret;
>  }
>  
> +static int tps6594_soft_shutdown(struct tps6594 *tps)

Why do you have a whole separate function that itself is only called
once and only conducts a single one call to one other function?

> +{
> +	return regmap_update_bits(tps->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
> +				TPS6594_BIT_TRIGGER_I2C(0),
> +				TPS6594_BIT_TRIGGER_I2C(0));
> +}
> +
> +static int tps6594_power_off_handler(struct sys_off_data *data)
> +{
> +	tps6594_soft_shutdown(data->cb_data);
> +	return NOTIFY_DONE;
> +}
> +
>  int tps6594_device_init(struct tps6594 *tps, bool enable_crc)
>  {
>  	struct device *dev = tps->dev;
> @@ -623,6 +637,7 @@ int tps6594_device_init(struct tps6594 *tps, bool enable_crc)
>  	const struct mfd_cell *cells;
>  	int n_cells;
>  	bool pwr_button;
> +	bool system_power_controller;
>  
>  	if (enable_crc) {
>  		ret = tps6594_enable_crc(tps);
> @@ -681,6 +696,15 @@ int tps6594_device_init(struct tps6594 *tps, bool enable_crc)
>  			return dev_err_probe(dev, ret, "Failed to add RTC child device\n");
>  	}
>  
> +	system_power_controller = of_property_read_bool(dev->of_node, "system-power-controller");
> +	if (system_power_controller) {
> +		ret = devm_register_power_off_handler(tps->dev,
> +								tps6594_power_off_handler,
> +								tps);

This alignment is odd.

> +		if (ret)
> +			return dev_err_probe(dev, ret, "Failed to register power-off handler\n");
> +	}
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(tps6594_device_init);
> 
> -- 
> 2.43.0
> 

-- 
Lee Jones [李琼斯]