linux-kernel - [PATCH RFC 06/11] power: supply: max77693: Set charge current limits during init

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Message-Id: <20240530-max77693-charger-extcon-v1-6-dc2a9e5bdf30@gmail.com>
Date: Thu, 30 May 2024 10:55:56 +0200
From: Artur Weber <aweber.kernel@...il.com>
To: Krzysztof Kozlowski <krzk@...nel.org>, 
 Chanwoo Choi <cw00.choi@...sung.com>
Cc: Sebastian Reichel <sre@...nel.org>, Rob Herring <robh@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Lee Jones <lee@...nel.org>, 
 Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Alim Akhtar <alim.akhtar@...sung.com>, linux-pm@...r.kernel.org, 
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, linux-samsung-soc@...r.kernel.org, 
 ~postmarketos/upstreaming@...ts.sr.ht, Henrik Grimler <henrik@...mler.se>, 
 Wolfgang Wiedmeyer <wolfgit@...dmeyer.de>, 
 Denis 'GNUtoo' Carikli <GNUtoo@...erdimension.org>, 
 Artur Weber <aweber.kernel@...il.com>
Subject: [PATCH RFC 06/11] power: supply: max77693: Set charge current
 limits during init

There are two charger current limit registers:

- Fast charge current limit (which controls current going from the
  charger to the battery);
- CHGIN input current limit (which controls current going into the
  charger through the cable, and is managed by the CHARGER regulator).

Add functions for setting both of the values, and set them to a
safe default value of 500mA at initialization.

The default value for the fast charge current limit can be modified
by setting the maxim,fast-charge-current-microamp DT property; the
CHGIN input current limit will be set up later in the charger detection
mechanism.

Signed-off-by: Artur Weber <aweber.kernel@...il.com>
---
 drivers/power/supply/max77693_charger.c | 45 +++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c
index 894c35b750b3..d59b1524b0a4 100644
--- a/drivers/power/supply/max77693_charger.c
+++ b/drivers/power/supply/max77693_charger.c
@@ -28,6 +28,7 @@ struct max77693_charger {
 	u32 min_system_volt;
 	u32 thermal_regulation_temp;
 	u32 batttery_overcurrent;
+	u32 fast_charge_current;
 	u32 charge_input_threshold_volt;
 };
 
@@ -591,6 +592,35 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg,
 			CHG_CNFG_12_B2SOVRC_MASK, data);
 }
 
+static int max77693_set_input_current_limit(struct max77693_charger *chg,
+		unsigned int uamp)
+{
+	dev_dbg(chg->dev, "CHGIN input current limit: %u\n", uamp);
+
+	return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp);
+}
+
+static int max77693_set_fast_charge_current(struct max77693_charger *chg,
+		unsigned int uamp)
+{
+	unsigned int data;
+
+	data = (uamp / 1000) * 10 / 333; /* 0.1A/3 steps */
+
+	if (data > CHG_CNFG_02_CC_MASK) {
+		dev_err(chg->dev, "Wrong value for fast charge current\n");
+		return -EINVAL;
+	}
+
+	data <<= CHG_CNFG_02_CC_SHIFT;
+
+	dev_dbg(chg->dev, "Fast charge current: %u (0x%x)\n", uamp, data);
+
+	return regmap_update_bits(chg->max77693->regmap,
+			MAX77693_CHG_REG_CHG_CNFG_02,
+			CHG_CNFG_02_CC_MASK, data);
+}
+
 static int max77693_set_charge_input_threshold_volt(struct max77693_charger *chg,
 		unsigned int uvolt)
 {
@@ -668,6 +698,15 @@ static int max77693_reg_init(struct max77693_charger *chg)
 	if (ret)
 		return ret;
 
+	ret = max77693_set_fast_charge_current(chg, chg->fast_charge_current);
+	if (ret)
+		return ret;
+
+	ret = max77693_set_input_current_limit(chg,
+				DEFAULT_FAST_CHARGE_CURRENT);
+	if (ret)
+		return ret;
+
 	return max77693_set_charge_input_threshold_volt(chg,
 			chg->charge_input_threshold_volt);
 }
@@ -703,11 +742,17 @@ static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
 		chg->charge_input_threshold_volt =
 			DEFAULT_CHARGER_INPUT_THRESHOLD_VOLT;
 
+	if (of_property_read_u32(np, "maxim,fast-charge-current-microamp",
+			&chg->fast_charge_current))
+		chg->fast_charge_current = DEFAULT_FAST_CHARGE_CURRENT;
+
 	return 0;
 }
 #else /* CONFIG_OF */
 static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
 {
+	chg->fast_charge_current = DEFAULT_FAST_CHARGE_CURRENT;
+
 	return 0;
 }
 #endif /* CONFIG_OF */

-- 
2.45.1