linux-kernel - Re: [PATCH v2 5/5] mfd: rn5t618: register restart handler

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Message-ID: <20160616150328.GE4948@dell>
Date:	Thu, 16 Jun 2016 16:03:28 +0100
From:	Lee Jones <lee.jones@...aro.org>
To:	Stefan Agner <stefan@...er.ch>
Cc:	lgirdwood@...il.com, broonie@...nel.org, khilman@...libre.com,
	carlo@...one.org, b.galvani@...il.com, max.oss.09@...il.com,
	marcel@...wiler.com, linux@...linux.org.uk, galak@...eaurora.org,
	ijc+devicetree@...lion.org.uk, mark.rutland@....com,
	pawel.moll@....com, robh+dt@...nel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-amlogic@...ts.infradead.org
Subject: Re: [PATCH v2 5/5] mfd: rn5t618: register restart handler

On Tue, 07 Jun 2016, Stefan Agner wrote:

> Use the PMIC's repower capability for reboots. Register a restart
> handler with use a default priority of 128.

Care to elaborate as to why you're using 128?

> Reviewed-by: Marcel Ziswiler <marcel.ziswiler@...adex.com>
> Signed-off-by: Stefan Agner <stefan@...er.ch>

Chronological.

> ---
>  drivers/mfd/rn5t618.c | 40 ++++++++++++++++++++++++++++++++++------
>  1 file changed, 34 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mfd/rn5t618.c b/drivers/mfd/rn5t618.c
> index d9b4d40..6bc0863 100644
> --- a/drivers/mfd/rn5t618.c
> +++ b/drivers/mfd/rn5t618.c
> @@ -12,11 +12,13 @@
>   * along with this program. If not, see <http://www.gnu.org/licenses/>.
>   */
>  
> +#include <linux/delay.h>
>  #include <linux/i2c.h>
>  #include <linux/mfd/core.h>
>  #include <linux/mfd/rn5t618.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
> +#include <linux/reboot.h>
>  #include <linux/regmap.h>
>  
>  static const struct mfd_cell rn5t618_cells[] = {
> @@ -50,17 +52,34 @@ static const struct regmap_config rn5t618_regmap_config = {
>  };
>  
>  static struct rn5t618 *rn5t618_pm_power_off;
> +static struct notifier_block rn5t618_restart_handler;
>  
> -static void rn5t618_power_off(void)
> +static void rn5t618_trigger_poweroff_sequence(bool repower)
>  {
>  	/* disable automatic repower-on */
>  	regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
> -			   RN5T618_REPCNT_REPWRON, 0);
> +			   RN5T618_REPCNT_REPWRON, repower);
>  	/* start power-off sequence */
>  	regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
>  			   RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
>  }
>  
> +static void rn5t618_power_off(void)
> +{
> +	rn5t618_trigger_poweroff_sequence(false);
> +}
> +
> +static int rn5t618_restart(struct notifier_block *this,
> +			    unsigned long mode, void *cmd)
> +{
> +	rn5t618_trigger_poweroff_sequence(true);
> +
> +	mdelay(10);

Why 10ms?

> +	return NOTIFY_DONE;
> +}
> +
> +
>  static const struct of_device_id rn5t618_of_match[] = {
>  	{ .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
>  	{ .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
> @@ -103,13 +122,22 @@ static int rn5t618_i2c_probe(struct i2c_client *i2c,
>  		return ret;
>  	}
>  
> +	rn5t618_pm_power_off = priv;
>  	if (of_device_is_system_power_controller(i2c->dev.of_node)) {
> -		if (!pm_power_off) {
> -			rn5t618_pm_power_off = priv;
> +		if (!pm_power_off)
>  			pm_power_off = rn5t618_power_off;
> -		} else {
> +		else
>  			dev_err(&i2c->dev, "Failed to set poweroff capability, already defined\n");
> -		}
> +	}
> +
> +	rn5t618_restart_handler.notifier_call = rn5t618_restart;
> +	rn5t618_restart_handler.priority = 128;
> +
> +	ret = register_restart_handler(&rn5t618_restart_handler);
> +	if (ret) {
> +		dev_err(&i2c->dev, "%s: cannot register restart handler, %d\n",
> +				__func__, ret);

Don't use __func__ in log prints.

Users don't care and developers know how to use `git grep`.

> +		return ret;
>  	}
>  
>  	return 0;

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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