Re: [PATCH v2 2/2] mfd: rk808: Add restart functionality

[Lee Jones <lee.jones@linaro.org>]

Rockchip guys,

I'd really appreciate your input on these two patches please.

Please provide Reviewed-by/Tested-by tags.

On Wed, 07 Mar 2018, Daniel Schultz wrote:
> When using Rockchip SoCs with rk805/808/818 PMICs, restarts are realized by
> setting the reset registers in the "Clock and Reset Unit".
> 
> Since all three shutdown functions have almost the same code, all logic
> from the shutdown functions can be refactored to a new function
> "rk808_update_bits", which can update a register by a given address and
> bitmask.
> 
> After that, notifier blocks and the restart functions were added to the
> driver. Like the shutdown function, the restart is bound to the
> "rockchip,system-power-controller" device tree property and can easily
> revoked to the software restart by removing the property.
> 
> Signed-off-by: Daniel Schultz <d.schultz@phytec.de>
> ---
> Changes:
> 	v2: Re-submit with recipients from Rockchip.
> 
>  drivers/mfd/rk808.c       | 97 ++++++++++++++++++++++++++++++-----------------
>  include/linux/mfd/rk808.h |  1 +
>  2 files changed, 63 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/mfd/rk808.c b/drivers/mfd/rk808.c
> index d138721..2c68f8c 100644
> --- a/drivers/mfd/rk808.c
> +++ b/drivers/mfd/rk808.c
> @@ -27,6 +27,7 @@
>  #include <linux/module.h>
>  #include <linux/of_device.h>
>  #include <linux/regmap.h>
> +#include <linux/reboot.h>
>  
>  struct rk808_reg_data {
>  	int addr;
> @@ -369,59 +370,73 @@ static const struct regmap_irq_chip rk818_irq_chip = {
>  
>  static struct i2c_client *rk808_i2c_client;
>  
> -static void rk805_device_shutdown(void)
> +static void rk808_update_bits(unsigned int reg, unsigned int bit_mask)
>  {
>  	int ret;
>  	struct rk808 *rk808 = i2c_get_clientdata(rk808_i2c_client);
>  
>  	if (!rk808) {
>  		dev_warn(&rk808_i2c_client->dev,
> -			 "have no rk805, so do nothing here\n");
> +			 "have no %s, so do nothing here\n",
> +			 rk808->regmap_irq_chip->name);
>  		return;
>  	}
>  
>  	ret = regmap_update_bits(rk808->regmap,
> -				 RK805_DEV_CTRL_REG,
> -				 DEV_OFF, DEV_OFF);
> +				 reg,
> +				 bit_mask, bit_mask);
>  	if (ret)
> -		dev_err(&rk808_i2c_client->dev, "power off error!\n");
> +		dev_err(&rk808_i2c_client->dev, "can't write to DEVCTRL: %x!\n",
> +			ret);
>  }
>  
> -static void rk808_device_shutdown(void)
> +static void rk805_device_shutdown(void)
>  {
> -	int ret;
> -	struct rk808 *rk808 = i2c_get_clientdata(rk808_i2c_client);
> -
> -	if (!rk808) {
> -		dev_warn(&rk808_i2c_client->dev,
> -			 "have no rk808, so do nothing here\n");
> -		return;
> -	}
> +	rk808_update_bits(RK805_DEV_CTRL_REG, DEV_OFF);
> +}
> +static int rk805_restart_notify(struct notifier_block *this,
> +				   unsigned long mode, void *cmd)
> +{
> +	rk808_update_bits(RK805_DEV_CTRL_REG, DEV_OFF_RST);
> +	return NOTIFY_DONE;
> +}
>  
> -	ret = regmap_update_bits(rk808->regmap,
> -				 RK808_DEVCTRL_REG,
> -				 DEV_OFF_RST, DEV_OFF_RST);
> -	if (ret)
> -		dev_err(&rk808_i2c_client->dev, "power off error!\n");
> +static void rk808_device_shutdown(void)
> +{
> +	rk808_update_bits(RK808_DEVCTRL_REG, DEV_OFF_RST);
> +}
> +static int rk808_restart_notify(struct notifier_block *this,
> +				   unsigned long mode, void *cmd)
> +{
> +	rk808_update_bits(RK808_DEVCTRL_REG, DEV_OFF);
> +	return NOTIFY_DONE;
>  }
>  
>  static void rk818_device_shutdown(void)
>  {
> -	int ret;
> -	struct rk808 *rk808 = i2c_get_clientdata(rk808_i2c_client);
> +	rk808_update_bits(RK818_DEVCTRL_REG, DEV_OFF_RST);
> +}
> +static int rk818_restart_notify(struct notifier_block *this,
> +				   unsigned long mode, void *cmd)
> +{
> +	rk808_update_bits(RK818_DEVCTRL_REG, DEV_OFF);
> +	return NOTIFY_DONE;
> +}
>  
> -	if (!rk808) {
> -		dev_warn(&rk808_i2c_client->dev,
> -			 "have no rk818, so do nothing here\n");
> -		return;
> -	}
> +static struct notifier_block rk805_restart_handler = {
> +	.notifier_call = rk805_restart_notify,
> +	.priority = 196,
> +};
>  
> -	ret = regmap_update_bits(rk808->regmap,
> -				 RK818_DEVCTRL_REG,
> -				 DEV_OFF_RST, DEV_OFF_RST);
> -	if (ret)
> -		dev_err(&rk808_i2c_client->dev, "power off error!\n");
> -}
> +static struct notifier_block rk808_restart_handler = {
> +	.notifier_call = rk808_restart_notify,
> +	.priority = 196,
> +};
> +
> +static struct notifier_block rk818_restart_handler = {
> +	.notifier_call = rk818_restart_notify,
> +	.priority = 196,
> +};
>  
>  static const struct of_device_id rk808_of_match[] = {
>  	{ .compatible = "rockchip,rk805" },
> @@ -476,6 +491,7 @@ static int rk808_probe(struct i2c_client *client,
>  		cells = rk805s;
>  		nr_cells = ARRAY_SIZE(rk805s);
>  		pm_pwroff_fn = rk805_device_shutdown;
> +		rk808->nb = &rk805_restart_handler;
>  		break;
>  	case RK808_ID:
>  		rk808->regmap_cfg = &rk808_regmap_config;
> @@ -485,6 +501,7 @@ static int rk808_probe(struct i2c_client *client,
>  		cells = rk808s;
>  		nr_cells = ARRAY_SIZE(rk808s);
>  		pm_pwroff_fn = rk808_device_shutdown;
> +		rk808->nb = &rk808_restart_handler;
>  		break;
>  	case RK818_ID:
>  		rk808->regmap_cfg = &rk818_regmap_config;
> @@ -494,6 +511,7 @@ static int rk808_probe(struct i2c_client *client,
>  		cells = rk818s;
>  		nr_cells = ARRAY_SIZE(rk818s);
>  		pm_pwroff_fn = rk818_device_shutdown;
> +		rk808->nb = &rk818_restart_handler;
>  		break;
>  	default:
>  		dev_err(&client->dev, "Unsupported RK8XX ID %lu\n",
> @@ -546,11 +564,18 @@ static int rk808_probe(struct i2c_client *client,
>  
>  	pm_off = of_property_read_bool(np,
>  				"rockchip,system-power-controller");
> -	if (pm_off && !pm_power_off) {
> +	if (pm_off) {
>  		rk808_i2c_client = client;
> -		pm_power_off = pm_pwroff_fn;
> +		if (!pm_power_off)
> +			pm_power_off = pm_pwroff_fn;
> +		if (rk808->nb) {
> +			ret = register_restart_handler(rk808->nb);
> +			if (ret)
> +				dev_err(&client->dev,
> +					"cannot register restart handler, %d\n",
> +					ret);
> +		}
>  	}
> -
>  	return 0;
>  
>  err_irq:
> @@ -564,6 +589,8 @@ static int rk808_remove(struct i2c_client *client)
>  
>  	regmap_del_irq_chip(client->irq, rk808->irq_data);
>  	pm_power_off = NULL;
> +	if (rk808->nb)
> +		unregister_restart_handler(rk808->nb);
>  
>  	return 0;
>  }
> diff --git a/include/linux/mfd/rk808.h b/include/linux/mfd/rk808.h
> index 338e0f6..9c26ca2 100644
> --- a/include/linux/mfd/rk808.h
> +++ b/include/linux/mfd/rk808.h
> @@ -453,5 +453,6 @@ struct rk808 {
>  	long				variant;
>  	const struct regmap_config	*regmap_cfg;
>  	const struct regmap_irq_chip	*regmap_irq_chip;
> +	struct notifier_block		*nb;
>  };
>  #endif /* __LINUX_REGULATOR_RK808_H */

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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