linux-kernel - [PATCH v6] power: supply: max77705

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Message-Id: <20250925-max77705_77976_charger_improvement-v6-1-972c716c17d1@gmail.com>
Date: Thu, 25 Sep 2025 22:09:56 +0300
From: Dzmitry Sankouski <dsankouski@...il.com>
To: Chanwoo Choi <cw00.choi@...sung.com>, 
 Krzysztof Kozlowski <krzk@...nel.org>, Lee Jones <lee@...nel.org>, 
 Sebastian Reichel <sre@...nel.org>, 
 Luca Ceresoli <luca.ceresoli@...tlin.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>, 
 Sebastian Reichel <sebastian.reichel@...labora.com>, 
 linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org, 
 Dzmitry Sankouski <dsankouski@...il.com>
Subject: [PATCH v6] 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 <dsankouski@...il.com>
---
This series consists of:
- max77705: interrupt handling fix
- max77705: make input current limit and charge current limit properties
  writable
- max77705: add adaptive input current limit feature
- max77705: switch to regfields
- max77705: refactoring
- max77976: change property for current charge limit value
---
Changes in v6:
- simplify aicl feature - remove aicl work
- rebase on latest linux-next
- Link to v5: https://lore.kernel.org/r/20250920-max77705_77976_charger_improvement-v5-1-aab0aef82cc4@gmail.com

Changes in v5:
- rebase on latest linux-next, dropping already applied patches
- optimize code to drop is_aicl_irq_disabled variable
- Link to v4: https://lore.kernel.org/r/20250918-max77705_77976_charger_improvement-v4-0-11ec9188f489@gmail.com

Changes in v4:
- fix commit message
- use IRQF_TRIGGER_NONE, because non physical irqs
- minor rename refactoring
- rebase on latest linux-next
- patch reorder: put fixes patch first
- aicl feature cleanup
- Link to v3: https://lore.kernel.org/r/20250911-max77705_77976_charger_improvement-v3-0-35203686fa29@gmail.com

Changes in v3:
- move interrupt request before interrupt handler work initialization
- Link to v2: https://lore.kernel.org/r/20250909-max77705_77976_charger_improvement-v2-0-a8d2fba47159@gmail.com

Changes in v2:
- fix charger register protection unlock
- Link to v1: https://lore.kernel.org/r/20250830-max77705_77976_charger_improvement-v1-0-e976db3fd432@gmail.com
---
Changes in v6:
- drop aicl work
- handle current decrease sequence in a loop

Changes in v5:
- add _MS suffix to AICL_WORK_DELAY
- optimize code to drop is_aicl_irq_disabled variable

Changes in v4:
- fix intendation
- use IRQF_TRIGGER_NONE, because this is not physical irq
- use dev_err_probe instead of pr_err
- remove excessive chgin irq request
- remove pr_infos
---
 drivers/power/supply/max77705_charger.c | 42 +++++++++++++++++++++++++++++++++
 include/linux/power/max77705_charger.h  |  2 ++
 2 files changed, 44 insertions(+)

diff --git a/drivers/power/supply/max77705_charger.c b/drivers/power/supply/max77705_charger.c
index b1a227bf72e2..35cdb10a0e89 100644
--- a/drivers/power/supply/max77705_charger.c
+++ b/drivers/power/supply/max77705_charger.c
@@ -40,6 +40,39 @@ static enum power_supply_property max77705_charger_props[] = {
 	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;
@@ -632,6 +665,15 @@ static int max77705_charger_probe(struct i2c_client *i2c)
 		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;
+	}
+
 	ret = max77705_charger_enable(chg);
 	if (ret) {
 		dev_err_probe(dev, ret, "failed to enable charge\n");
diff --git a/include/linux/power/max77705_charger.h b/include/linux/power/max77705_charger.h
index 6653abfdf747..b3950ce0625e 100644
--- a/include/linux/power/max77705_charger.h
+++ b/include/linux/power/max77705_charger.h
@@ -123,6 +123,8 @@
 #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

---
base-commit: 8e2755d7779a95dd61d8997ebce33ff8b1efd3fb
change-id: 20250830-max77705_77976_charger_improvement-e3f417bfaa56

Best regards,
-- 
Dzmitry Sankouski <dsankouski@...il.com>