[PATCH v2 7/9] power: supply: max77693: Add support for detecting and enabling OTG

[Lee Jones]

On Mon, 15 Jul 2024, Artur Weber wrote:

> Building upon the newly added extcon detection support, add detection
> for USB OTG cables (EXTCON_USB_HOST type), and enable/disable the OTG
> bits as needed.
> 
> Signed-off-by: Artur Weber <aweber.kernel at gmail.com>
> ---
> Changes in v2:
> - Added CHGIN OTG current limit value
> - Squashed MFD header register changes into this commit
> ---
>  drivers/power/supply/max77693_charger.c | 103 +++++++++++++++++++++++++++-----

>  include/linux/mfd/max77693-private.h    |   5 ++

Acked-by: Lee Jones <lee at kernel.org>

>  2 files changed, 94 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c
> index 2dc273dd96ee..34d68b1050d4 100644
> --- a/drivers/power/supply/max77693_charger.c
> +++ b/drivers/power/supply/max77693_charger.c
> @@ -669,6 +669,16 @@ static int max77693_reg_init(struct max77693_charger *chg)
>  	if (ret)
>  		return ret;
>  
> +	/* Set OTG current limit to 900 mA */
> +	data = (0x1 << CHG_CNFG_02_OTG_ILIM_SHIFT);
> +	ret = regmap_update_bits(chg->max77693->regmap,
> +				MAX77693_CHG_REG_CHG_CNFG_02,
> +				CHG_CNFG_02_OTG_ILIM_MASK, data);
> +	if (ret) {
> +		dev_err(chg->dev, "Error setting OTG current limit: %d\n", ret);
> +		return ret;
> +	}
> +
>  	return max77693_set_charge_input_threshold_volt(chg,
>  			chg->charge_input_threshold_volt);
>  }
> @@ -690,11 +700,42 @@ static int max77693_set_charging(struct max77693_charger *chg, bool enable)
>  	return ret;
>  }
>  
> +static int max77693_set_otg(struct max77693_charger *chg, bool enable)
> +{
> +	struct regmap *regmap = chg->max77693->regmap;
> +	unsigned int data;
> +	bool is_enabled;
> +	int ret;
> +
> +	ret = regmap_read(regmap, MAX77693_CHG_REG_CHG_CNFG_00, &data);
> +	if (ret)
> +		return ret;
> +
> +	is_enabled = !!(data & CHG_CNFG_00_OTG_MASK);
> +
> +	if (enable && !is_enabled) {
> +		/* OTG on, boost on, DIS_MUIC_CTRL on */
> +		data |= CHG_CNFG_00_OTG_MASK | CHG_CNFG_00_BOOST_MASK \
> +				| CHG_CNFG_00_DIS_MUIC_CTRL_MASK;
> +
> +	} else if (!enable && is_enabled) {
> +		/* OTG off, boost off, DIS_MUIC_CTRL off */
> +		data &= ~(CHG_CNFG_00_OTG_MASK | CHG_CNFG_00_BOOST_MASK \
> +				| CHG_CNFG_00_DIS_MUIC_CTRL_MASK);
> +	}
> +
> +	return regmap_write(chg->max77693->regmap,
> +			MAX77693_CHG_REG_CHG_CNFG_00,
> +			data);
> +}
> +
>  static void max77693_charger_extcon_work(struct work_struct *work)
>  {
>  	struct max77693_charger *chg = container_of(work, struct max77693_charger,
>  						  cable.work);
>  	struct extcon_dev *edev = chg->cable.edev;
> +	bool set_charging, set_otg;
> +	unsigned int current_limit;
>  	int connector, state;
>  	int ret;
>  
> @@ -707,31 +748,61 @@ static void max77693_charger_extcon_work(struct work_struct *work)
>  
>  	switch (connector) {
>  	case EXTCON_CHG_USB_SDP:
> -	case EXTCON_CHG_USB_DCP:
>  	case EXTCON_CHG_USB_CDP:
> +	case EXTCON_CHG_USB_SLOW:
> +		current_limit = 500000; /* 500 mA */
> +		set_charging = true;
> +		set_otg = false;
> +
> +		dev_info(chg->dev, "slow charging. connector type: %d\n",
> +			 connector);
> +		break;
> +	case EXTCON_CHG_USB_DCP:
>  	case EXTCON_CHG_USB_ACA:
>  	case EXTCON_CHG_USB_FAST:
> -	case EXTCON_CHG_USB_SLOW:
>  	case EXTCON_CHG_USB_PD:
> -		ret = max77693_set_charging(chg, true);
> -		if (ret) {
> -			dev_err(chg->dev, "failed to enable charging\n");
> -			break;
> -		}
> -		dev_info(chg->dev, "charging. connector type: %d\n",
> +		current_limit = chg->fast_charge_current;
> +		set_charging = true;
> +		set_otg = false;
> +
> +		dev_info(chg->dev, "fast charging. connector type: %d\n",
> +			 connector);
> +		break;
> +	case EXTCON_USB_HOST:
> +		current_limit = 500000; /* 500 mA */
> +		set_charging = false;
> +		set_otg = true;
> +
> +		dev_info(chg->dev, "USB host. connector type: %d\n",
>  			 connector);
>  		break;
>  	default:
> -		ret = max77693_set_charging(chg, false);
> -		if (ret) {
> -			dev_err(chg->dev, "failed to disable charging\n");
> -			break;
> -		}
> -		dev_info(chg->dev, "charging. connector type: %d\n",
> +		current_limit = 500000; /* 500 mA */
> +		set_charging = false;
> +		set_otg = false;
> +
> +		dev_info(chg->dev, "disconnected. connector type: %d\n",
>  			 connector);
>  		break;
>  	}
>  
> +	ret = max77693_set_current_limit(chg, current_limit);
> +	if (ret) {
> +		dev_err(chg->dev, "failed to set current limit (%d)\n", ret);
> +		goto out;
> +	}
> +
> +	ret = max77693_set_charging(chg, set_charging);
> +	if (ret) {
> +		dev_err(chg->dev, "failed to set charging (%d)\n", ret);
> +		goto out;
> +	}
> +
> +	ret = max77693_set_otg(chg, set_otg);
> +	if (ret)
> +		dev_err(chg->dev, "failed to set OTG (%d)\n", ret);
> +
> +out:
>  	power_supply_changed(chg->charger);
>  }
>  
> @@ -793,6 +864,10 @@ static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
>  			&chg->batttery_overcurrent))
>  		chg->batttery_overcurrent = DEFAULT_BATTERY_OVERCURRENT;
>  
> +	if (of_property_read_u32(np, "maxim,fast-charge-current-microamp",
> +			&chg->fast_charge_current))
> +		chg->fast_charge_current = DEFAULT_FAST_CHARGE_CURRENT;
> +
>  	if (of_property_read_u32(np, "maxim,charge-input-threshold-microvolt",
>  			&chg->charge_input_threshold_volt))
>  		chg->charge_input_threshold_volt =
> diff --git a/include/linux/mfd/max77693-private.h b/include/linux/mfd/max77693-private.h
> index 4570646e2f33..313fcc3173f9 100644
> --- a/include/linux/mfd/max77693-private.h
> +++ b/include/linux/mfd/max77693-private.h
> @@ -209,7 +209,10 @@ enum max77693_charger_battery_state {
>  
>  /* MAX77693 CHG_CNFG_00 register */
>  #define CHG_CNFG_00_CHG_MASK		0x1
> +#define CHG_CNFG_00_OTG_MASK		0x2
>  #define CHG_CNFG_00_BUCK_MASK		0x4
> +#define CHG_CNFG_00_BOOST_MASK		0x8
> +#define CHG_CNFG_00_DIS_MUIC_CTRL_MASK	0x20
>  
>  /* MAX77693_CHG_REG_CHG_CNFG_01 register */
>  #define CHG_CNFG_01_FCHGTIME_SHIFT	0
> @@ -222,6 +225,8 @@ enum max77693_charger_battery_state {
>  /* MAX77693_CHG_REG_CHG_CNFG_02 register */
>  #define CHG_CNFG_02_CC_SHIFT		0
>  #define CHG_CNFG_02_CC_MASK		0x3F
> +#define CHG_CNFG_02_OTG_ILIM_SHIFT	7
> +#define CHG_CNFG_02_OTG_ILIM_MASK	0x80
>  
>  /* MAX77693_CHG_REG_CHG_CNFG_03 register */
>  #define CHG_CNFG_03_TOITH_SHIFT		0
> 
> -- 
> 2.45.2
> 

-- 
Lee Jones [李琼斯]