linux-kernel - [PATCH 1/3] pinctrl: cy8c95x0: Use single I2C lock

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Date: Tue, 21 May 2024 17:25:57 +0200
From: Patrick Rudolph <patrick.rudolph@...ements.com>
To: Patrick Rudolph <patrick.rudolph@...ements.com>,
	Linus Walleij <linus.walleij@...aro.org>
Cc: naresh.solanki@...ements.com,
	andy.shevchenko@...il.com,
	broonie@...nel.org,
	linux-gpio@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] pinctrl: cy8c95x0: Use single I2C lock

Currently there are 3 locks being used when accessing the chip, one
in the driver and one in each regmap. Reduce that to one driver only
lock that protects all regmap and regcache accesses.

Signed-off-by: Patrick Rudolph <patrick.rudolph@...ements.com>
---
 drivers/pinctrl/pinctrl-cy8c95x0.c | 32 ++++++++++++++++--------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-cy8c95x0.c b/drivers/pinctrl/pinctrl-cy8c95x0.c
index 981c569bd671..ca54d91fdc77 100644
--- a/drivers/pinctrl/pinctrl-cy8c95x0.c
+++ b/drivers/pinctrl/pinctrl-cy8c95x0.c
@@ -453,7 +453,6 @@ cy8c95x0_mux_reg_read(void *context, unsigned int off, unsigned int *val)
 	u8 port = CY8C95X0_MUX_REGMAP_TO_PORT(off);
 	int ret, reg = CY8C95X0_MUX_REGMAP_TO_REG(off);
 
-	mutex_lock(&chip->i2c_lock);
 	/* Select the correct bank */
 	ret = regmap_write(chip->regmap, CY8C95X0_PORTSEL, port);
 	if (ret < 0)
@@ -463,11 +462,7 @@ cy8c95x0_mux_reg_read(void *context, unsigned int off, unsigned int *val)
 	 * Read the register through direct access regmap. The target range
 	 * is marked volatile.
 	 */
-	ret = regmap_read(chip->regmap, reg, val);
-out:
-	mutex_unlock(&chip->i2c_lock);
-
-	return ret;
+	return regmap_read(chip->regmap, reg, val);
 }
 
 static int
@@ -477,7 +472,6 @@ cy8c95x0_mux_reg_write(void *context, unsigned int off, unsigned int val)
 	u8 port = CY8C95X0_MUX_REGMAP_TO_PORT(off);
 	int ret, reg = CY8C95X0_MUX_REGMAP_TO_REG(off);
 
-	mutex_lock(&chip->i2c_lock);
 	/* Select the correct bank */
 	ret = regmap_write(chip->regmap, CY8C95X0_PORTSEL, port);
 	if (ret < 0)
@@ -487,11 +481,7 @@ cy8c95x0_mux_reg_write(void *context, unsigned int off, unsigned int val)
 	 * Write the register through direct access regmap. The target range
 	 * is marked volatile.
 	 */
-	ret = regmap_write(chip->regmap, reg, val);
-out:
-	mutex_unlock(&chip->i2c_lock);
-
-	return ret;
+	return regmap_write(chip->regmap, reg, val);
 }
 
 static bool cy8c95x0_mux_accessible_register(struct device *dev, unsigned int off)
@@ -524,6 +514,7 @@ static const struct regmap_config cy8c95x0_muxed_regmap = {
 	.num_reg_defaults_raw = MUXED_STRIDE * BANK_SZ,
 	.readable_reg = cy8c95x0_mux_accessible_register,
 	.writeable_reg = cy8c95x0_mux_accessible_register,
+	.disable_locking = true,
 };
 
 /* Direct access regmap */
@@ -542,6 +533,7 @@ static const struct regmap_config cy8c95x0_i2c_regmap = {
 
 	.cache_type = REGCACHE_FLAT,
 	.max_register = CY8C95X0_COMMAND,
+	.disable_locking = true,
 };
 
 static inline int cy8c95x0_regmap_update_bits_base(struct cy8c95x0_pinctrl *chip,
@@ -559,6 +551,8 @@ static inline int cy8c95x0_regmap_update_bits_base(struct cy8c95x0_pinctrl *chip
 	if (reg == CY8C95X0_PORTSEL)
 		return -EINVAL;
 
+	mutex_lock(&chip->i2c_lock);
+
 	/* Registers behind the PORTSEL mux have their own regmap */
 	if (cy8c95x0_muxed_register(reg)) {
 		regmap = chip->muxed_regmap;
@@ -574,7 +568,7 @@ static inline int cy8c95x0_regmap_update_bits_base(struct cy8c95x0_pinctrl *chip
 
 	ret = regmap_update_bits_base(regmap, off, mask, val, change, async, force);
 	if (ret < 0)
-		return ret;
+		goto out;
 
 	/* Update the cache when a WC bit is written */
 	if (cy8c95x0_wc_register(reg) && (mask & val)) {
@@ -595,6 +589,8 @@ static inline int cy8c95x0_regmap_update_bits_base(struct cy8c95x0_pinctrl *chip
 			regcache_cache_only(regmap, false);
 		}
 	}
+out:
+	mutex_unlock(&chip->i2c_lock);
 
 	return ret;
 }
@@ -667,7 +663,9 @@ static int cy8c95x0_regmap_read(struct cy8c95x0_pinctrl *chip, unsigned int reg,
 				unsigned int port, unsigned int *read_val)
 {
 	struct regmap *regmap;
-	int off;
+	int off, ret;
+
+	mutex_lock(&chip->i2c_lock);
 
 	/* Registers behind the PORTSEL mux have their own regmap */
 	if (cy8c95x0_muxed_register(reg)) {
@@ -682,7 +680,11 @@ static int cy8c95x0_regmap_read(struct cy8c95x0_pinctrl *chip, unsigned int reg,
 			off = reg;
 	}
 
-	return regmap_read(regmap, off, read_val);
+	ret = regmap_read(regmap, off, read_val);
+
+	mutex_unlock(&chip->i2c_lock);
+
+	return ret;
 }
 
 static int cy8c95x0_write_regs_mask(struct cy8c95x0_pinctrl *chip, int reg,
-- 
2.44.0