Re: [PATCH v5 3/7] power: act8945a_charger: Add status change update support

[Sebastian Reichel]

Hi,

On Tue, Aug 16, 2016 at 04:59:54PM +0800, Wenyou Yang wrote:
> Add the charger status change interrupt support, it will report
> the power supply changed event.
> 
> This interrupt is generated by one of the conditions as below:
>  - the state machine jumps out of or into the EOC state
>  - the CHGIN input voltage goes out of or into the valid range.
>  - the battery temperature goes out of or into the valid range.
>  - the PRECHARGE time-out occurs.
>  - the total charge time-out occurs.

This is unsafe during module remove, since irq work may be scheduled
while power-supply is unregistered. You will have to add a remove
function, which does something like

charger->init_done = false;
cancel_work_sync(&charger->work);

-- Sebastian

> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> ---
> 
> Changes in v5: None
> Changes in v4:
>  - Use "interrupts" property, instead of "active-semi,lbo-gpios"
>    for irq.
> 
> Changes in v3: None
> Changes in v2: None
> 
>  drivers/power/supply/act8945a_charger.c | 82 ++++++++++++++++++++++++++++++---
>  1 file changed, 75 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/power/supply/act8945a_charger.c b/drivers/power/supply/act8945a_charger.c
> index 6ddfc1d..74778f7 100644
> --- a/drivers/power/supply/act8945a_charger.c
> +++ b/drivers/power/supply/act8945a_charger.c
> @@ -10,9 +10,11 @@
>   * published by the Free Software Foundation.
>   *
>   */
> +#include <linux/interrupt.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_gpio.h>
> +#include <linux/of_irq.h>
>  #include <linux/platform_device.h>
>  #include <linux/power_supply.h>
>  #include <linux/regmap.h>
> @@ -75,7 +77,11 @@ static const char *act8945a_charger_manufacturer = "Active-semi";
>  #define APCH_STATE_CSTATE_PRE		0x03
>  
>  struct act8945a_charger {
> +	struct power_supply *psy;
>  	struct regmap *regmap;
> +	struct work_struct work;
> +
> +	bool init_done;
>  };
>  
>  static int act8945a_get_charger_state(struct regmap *regmap, int *val)
> @@ -252,6 +258,47 @@ static const struct power_supply_desc act8945a_charger_desc = {
>  	.num_properties	= ARRAY_SIZE(act8945a_charger_props),
>  };
>  
> +static int act8945a_enable_interrupt(struct act8945a_charger *charger)
> +{
> +	struct regmap *regmap = charger->regmap;
> +	unsigned char ctrl;
> +	int ret;
> +
> +	ctrl = APCH_CTRL_CHGEOCOUT | APCH_CTRL_CHGEOCIN |
> +	       APCH_CTRL_INDIS | APCH_CTRL_INCON |
> +	       APCH_CTRL_TEMPOUT | APCH_CTRL_TEMPIN |
> +	       APCH_CTRL_TIMRPRE | APCH_CTRL_TIMRTOT;
> +	ret = regmap_write(regmap, ACT8945A_APCH_CTRL, ctrl);
> +	if (ret)
> +		return ret;
> +
> +	ctrl = APCH_STATUS_CHGSTAT | APCH_STATUS_INSTAT |
> +	       APCH_STATUS_TEMPSTAT | APCH_STATUS_TIMRSTAT;
> +	ret = regmap_write(regmap, ACT8945A_APCH_STATUS, ctrl);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static void act8945a_work(struct work_struct *work)
> +{
> +	struct act8945a_charger *charger =
> +			container_of(work, struct act8945a_charger, work);
> +
> +	power_supply_changed(charger->psy);
> +}
> +
> +static irqreturn_t act8945a_status_changed(int irq, void *dev_id)
> +{
> +	struct act8945a_charger *charger = dev_id;
> +
> +	if (charger->init_done)
> +		schedule_work(&charger->work);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  #define DEFAULT_TOTAL_TIME_OUT		3
>  #define DEFAULT_PRE_TIME_OUT		40
>  #define DEFAULT_INPUT_OVP_THRESHOLD	6600
> @@ -360,9 +407,8 @@ static int act8945a_charger_config(struct device *dev,
>  static int act8945a_charger_probe(struct platform_device *pdev)
>  {
>  	struct act8945a_charger *charger;
> -	struct power_supply *psy;
>  	struct power_supply_config psy_cfg = {};
> -	int ret;
> +	int irq, ret;
>  
>  	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
>  	if (!charger)
> @@ -378,17 +424,39 @@ static int act8945a_charger_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	irq = of_irq_get(pdev->dev.parent->of_node, 0);
> +	if (irq == -EPROBE_DEFER) {
> +		dev_err(&pdev->dev, "failed to find IRQ number\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	ret = devm_request_irq(&pdev->dev, irq, act8945a_status_changed,
> +			       IRQF_TRIGGER_FALLING, "act8945a_interrupt",
> +			       charger);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to request nIRQ pin IRQ\n");
> +		return ret;
> +	}
> +
>  	psy_cfg.of_node	= pdev->dev.parent->of_node;
>  	psy_cfg.drv_data = charger;
>  
> -	psy = devm_power_supply_register(&pdev->dev,
> -					 &act8945a_charger_desc,
> -					 &psy_cfg);
> -	if (IS_ERR(psy)) {
> +	charger->psy = devm_power_supply_register(&pdev->dev,
> +						  &act8945a_charger_desc,
> +						  &psy_cfg);
> +	if (IS_ERR(charger->psy)) {
>  		dev_err(&pdev->dev, "failed to register power supply\n");
> -		return PTR_ERR(psy);
> +		return PTR_ERR(charger->psy);
>  	}
>  
> +	INIT_WORK(&charger->work, act8945a_work);
> +
> +	ret = act8945a_enable_interrupt(charger);
> +	if (ret)
> +		return -EIO;
> +
> +	charger->init_done = true;
> +
>  	return 0;
>  }
>  
> -- 
> 2.7.4
>

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