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From: Detlev Casanova <detlev.casanova@collabora.com>
To: linux-kernel@vger.kernel.org
Cc: Dave Stevenson <dave.stevenson@raspberrypi.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>
Subject: [PATCH v2 8/9] regulator/rpi-panel-attiny: Don't read the LCD power status
Date: Fri, 21 Jan 2022 10:20:55 -0500	[thread overview]
Message-ID: <20220121152056.2044551-9-detlev.casanova@collabora.com> (raw)
In-Reply-To: <20220121152056.2044551-1-detlev.casanova@collabora.com>

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

The I2C to the Atmel is very fussy, and locks up easily on
Pi0-3 particularly on reads.

The LCD power status is controlled solely by this driver, so
rather than reading it back from the Atmel, use the cached
status last set.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/regulator/rpi-panel-attiny-regulator.c | 18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/drivers/regulator/rpi-panel-attiny-regulator.c b/drivers/regulator/rpi-panel-attiny-regulator.c
index 8090b9a485b5..8b80c0de1022 100644
--- a/drivers/regulator/rpi-panel-attiny-regulator.c
+++ b/drivers/regulator/rpi-panel-attiny-regulator.c
@@ -144,24 +144,8 @@ static int attiny_lcd_power_disable(struct regulator_dev *rdev)
 static int attiny_lcd_power_is_enabled(struct regulator_dev *rdev)
 {
 	struct attiny_lcd *state = rdev_get_drvdata(rdev);
-	unsigned int data;
-	int ret, i;
-
-	mutex_lock(&state->lock);
-
-	for (i = 0; i < 10; i++) {
-		ret = regmap_read(rdev->regmap, REG_PORTC, &data);
-		if (!ret)
-			break;
-		usleep_range(10000, 12000);
-	}
-
-	mutex_unlock(&state->lock);
-
-	if (ret < 0)
-		return ret;
 
-	return data & PC_RST_BRIDGE_N;
+	return state->port_states[REG_PORTC - REG_PORTA] & PC_RST_BRIDGE_N;
 }
 
 static const struct regulator_init_data attiny_regulator_default = {
-- 
2.34.1


  parent reply	other threads:[~2022-01-21 15:22 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-21 15:20 [PATCH v2 0/9] regulator: rpi-panel: Support official Raspberry Pi 7 inches touchscreen Detlev Casanova
2022-01-21 15:20 ` [PATCH v2 1/9] regulator: rpi-panel: Register with a unique backlight name Detlev Casanova
2022-01-21 16:26   ` Mark Brown
2022-01-21 18:11     ` Detlev Casanova
2022-01-21 15:20 ` [PATCH v2 2/9] regulator: rpi-panel: Handle I2C errors/timing to the Atmel Detlev Casanova
2022-01-21 15:20 ` [PATCH v2 3/9] regulator: rpi-panel: Serialise operations Detlev Casanova
2022-01-21 15:20 ` [PATCH v2 4/9] regulator: rpi-panel: Ensure the backlight is off during probe Detlev Casanova
2022-01-21 15:20 ` [PATCH v2 5/9] regulator: rpi-panel: Convert to drive lines directly Detlev Casanova
2022-01-21 15:20 ` [PATCH v2 6/9] regulator: rpi-panel: Add GPIO control for panel and touch resets Detlev Casanova
2022-01-21 15:20 ` [PATCH v2 7/9] regulator: rpi-panel: Remove get_brightness hook Detlev Casanova
2022-01-21 15:20 ` Detlev Casanova [this message]
2022-01-21 16:30   ` [PATCH v2 8/9] regulator/rpi-panel-attiny: Don't read the LCD power status Mark Brown
2022-01-24 20:22     ` Detlev Casanova
2022-01-24 20:45       ` Mark Brown
2022-01-21 15:20 ` [PATCH v2 9/9] regulator/rpi-panel-attiny: Use two transactions for I2C read Detlev Casanova

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