linux-kernel - [PATCH v5] Input: tsc2007 - enable cansleep pendown GPIO

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Date:   Sun, 02 Apr 2023 10:00:14 +0200
From:   Benjamin Bara <bbara93@...il.com>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     hns@...delico.com, richard.leitner@...ux.dev,
        christophe.jaillet@...adoo.fr, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Benjamin Bara <benjamin.bara@...data.com>,
        Richard Leitner <richard.leitner@...ux.dev>
Subject: [PATCH v5] Input: tsc2007 - enable cansleep pendown GPIO

From: Benjamin Bara <benjamin.bara@...data.com>

When a hard IRQ is triggered, the soft IRQ, which decides if an actual
pen down happened, should always be triggered. This enables the usage of
"can_sleep" GPIO chips as "pen down" GPIO, as the value is not read
during the hard IRQ anymore. This might be the case if the GPIO chip is
an expander behind i2c.

Signed-off-by: Benjamin Bara <benjamin.bara@...data.com>
Signed-off-by: Richard Leitner <richard.leitner@...data.com>
---
Hi!

Thanks for the feedback! The change unfortunately somehow got lost
during patch preparations - sorry for that. Here is the corrected
version with the missing part.

v4: https://lore.kernel.org/all/20230328-tsc2007-sleep-v4-1-2ede92ec9b71@skidata.com/

----
v5:
- actually use the can_sleep getter

v4:
- don't read value in hard IRQ

v3:
- extend commit message

v2:
- fix style mentioned by Christophe
---
 drivers/input/touchscreen/tsc2007_core.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/input/touchscreen/tsc2007_core.c b/drivers/input/touchscreen/tsc2007_core.c
index 3c793fb70a0e..21916a30fb76 100644
--- a/drivers/input/touchscreen/tsc2007_core.c
+++ b/drivers/input/touchscreen/tsc2007_core.c
@@ -172,19 +172,6 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
-{
-	struct tsc2007 *ts = handle;
-
-	if (tsc2007_is_pen_down(ts))
-		return IRQ_WAKE_THREAD;
-
-	if (ts->clear_penirq)
-		ts->clear_penirq();
-
-	return IRQ_HANDLED;
-}
-
 static void tsc2007_stop(struct tsc2007 *ts)
 {
 	ts->stopped = true;
@@ -226,7 +213,7 @@ static int tsc2007_get_pendown_state_gpio(struct device *dev)
 	struct i2c_client *client = to_i2c_client(dev);
 	struct tsc2007 *ts = i2c_get_clientdata(client);
 
-	return gpiod_get_value(ts->gpiod);
+	return gpiod_get_value_cansleep(ts->gpiod);
 }
 
 static int tsc2007_probe_properties(struct device *dev, struct tsc2007 *ts)
@@ -376,7 +363,7 @@ static int tsc2007_probe(struct i2c_client *client)
 	}
 
 	err = devm_request_threaded_irq(&client->dev, ts->irq,
-					tsc2007_hard_irq, tsc2007_soft_irq,
+					NULL, tsc2007_soft_irq,
 					IRQF_ONESHOT,
 					client->dev.driver->name, ts);
 	if (err) {

---
base-commit: 197b6b60ae7bc51dd0814953c562833143b292aa
change-id: 20230328-tsc2007-sleep-f65953ae32d0

Best regards,
-- 
Benjamin Bara <benjamin.bara@...data.com>