power: supply: max77705_charger: implement aicl feature

Adaptive input current allows charger to reduce it's current
consumption, when source is not able to provide enough power.

Signed-off-by: Dzmitry Sankouski <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/max77705_charger.c

···
 	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
 };
 
+static irqreturn_t max77705_aicl_irq(int irq, void *irq_drv_data)
+{
+	struct max77705_charger_data *chg = irq_drv_data;
+	unsigned int regval, irq_status;
+	int err;
+
+	err = regmap_read(chg->regmap, MAX77705_CHG_REG_INT_OK, &irq_status);
+	if (err < 0)
+		return IRQ_HANDLED;
+
+	// irq is fiered at the end of current decrease sequence too
+	// early check AICL_I bit to guard against that excess irq call
+	while (!(irq_status & BIT(MAX77705_AICL_I))) {
+		err = regmap_field_read(chg->rfield[MAX77705_CHG_CHGIN_LIM], &regval);
+		if (err < 0)
+			return IRQ_HANDLED;
+
+		regval--;
+
+		err = regmap_field_write(chg->rfield[MAX77705_CHG_CHGIN_LIM], regval);
+		if (err < 0)
+			return IRQ_HANDLED;
+
+		msleep(AICL_WORK_DELAY_MS);
+
+		err = regmap_read(chg->regmap, MAX77705_CHG_REG_INT_OK, &irq_status);
+		if (err < 0)
+			return IRQ_HANDLED;
+	}
+
+	return IRQ_HANDLED;
+}
+
 static irqreturn_t max77705_chgin_irq(int irq, void *irq_drv_data)
 {
 	struct max77705_charger_data *chg = irq_drv_data;
···
 					"chgin-irq", chg);
 	if (ret) {
 		dev_err_probe(dev, ret, "Failed to Request chgin IRQ\n");
+		goto destroy_wq;
+	}
+
+	ret = devm_request_threaded_irq(dev, regmap_irq_get_virq(irq_data, MAX77705_AICL_I),
+					NULL, max77705_aicl_irq,
+					IRQF_TRIGGER_NONE,
+					"aicl-irq", chg);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to Request aicl IRQ\n");
 		goto destroy_wq;
 	}
 

include/linux/power/max77705_charger.h

···
 #define MAX77705_DISABLE_SKIP		1
 #define MAX77705_AUTO_SKIP		0
 
+#define AICL_WORK_DELAY_MS		100
+
 /* uA */
 #define MAX77705_CURRENT_CHGIN_STEP	25000
 #define MAX77705_CURRENT_CHG_STEP	50000