From: Hugo Villeneuve hvilleneuve@dimonoff.com
The current reset pulse width is measured to be 5us on a Renesas RZ/G2L SOM. The manufacturer's minimum reset pulse width is specified as 10us.
Extend reset pulse width to make sure it is long enough on all platforms.
Also reword confusing comments about reset pin assertion.
Fixes: 5b0c03e24a06 ("Input: Add driver for Cypress Generation 5 touchscreen") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com --- drivers/input/touchscreen/cyttsp5.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c index eafe5a9b8964..bb09e84d0e92 100644 --- a/drivers/input/touchscreen/cyttsp5.c +++ b/drivers/input/touchscreen/cyttsp5.c @@ -870,13 +870,16 @@ static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq, ts->input->phys = ts->phys; input_set_drvdata(ts->input, ts);
- /* Reset the gpio to be in a reset state */ + /* Assert gpio to be in a reset state */ ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(ts->reset_gpio)) { error = PTR_ERR(ts->reset_gpio); dev_err(dev, "Failed to request reset gpio, error %d\n", error); return error; } + + fsleep(1000); /* Ensure long-enough reset pulse (minimum 10us). */ + gpiod_set_value_cansleep(ts->reset_gpio, 0);
/* Need a delay to have device up */
base-commit: 0de63bb7d91975e73338300a57c54b93d3cc151c
On Wed, 5 Feb 2025, at 5:01 AM, Hugo Villeneuve wrote:
From: Hugo Villeneuve hvilleneuve@dimonoff.com
The current reset pulse width is measured to be 5us on a Renesas RZ/G2L SOM. The manufacturer's minimum reset pulse width is specified as 10us.
Extend reset pulse width to make sure it is long enough on all platforms.
Also reword confusing comments about reset pin assertion.
Fixes: 5b0c03e24a06 ("Input: Add driver for Cypress Generation 5 touchscreen") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com
Acked-by: Alistair Francis alistair@alistair23.me
drivers/input/touchscreen/cyttsp5.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c index eafe5a9b8964..bb09e84d0e92 100644 --- a/drivers/input/touchscreen/cyttsp5.c +++ b/drivers/input/touchscreen/cyttsp5.c @@ -870,13 +870,16 @@ static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq, ts->input->phys = ts->phys; input_set_drvdata(ts->input, ts);
- /* Reset the gpio to be in a reset state */
- /* Assert gpio to be in a reset state */
ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(ts->reset_gpio)) { error = PTR_ERR(ts->reset_gpio); dev_err(dev, "Failed to request reset gpio, error %d\n", error); return error; }
- fsleep(1000); /* Ensure long-enough reset pulse (minimum 10us). */
gpiod_set_value_cansleep(ts->reset_gpio, 0); /* Need a delay to have device up */
base-commit: 0de63bb7d91975e73338300a57c54b93d3cc151c
2.39.5
On Tue, Feb 04, 2025 at 02:01:00PM -0500, Hugo Villeneuve wrote:
From: Hugo Villeneuve hvilleneuve@dimonoff.com
The current reset pulse width is measured to be 5us on a Renesas RZ/G2L SOM. The manufacturer's minimum reset pulse width is specified as 10us.
Extend reset pulse width to make sure it is long enough on all platforms.
Also reword confusing comments about reset pin assertion.
Fixes: 5b0c03e24a06 ("Input: Add driver for Cypress Generation 5 touchscreen") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com
drivers/input/touchscreen/cyttsp5.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c index eafe5a9b8964..bb09e84d0e92 100644 --- a/drivers/input/touchscreen/cyttsp5.c +++ b/drivers/input/touchscreen/cyttsp5.c @@ -870,13 +870,16 @@ static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq, ts->input->phys = ts->phys; input_set_drvdata(ts->input, ts);
- /* Reset the gpio to be in a reset state */
- /* Assert gpio to be in a reset state */ ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(ts->reset_gpio)) { error = PTR_ERR(ts->reset_gpio); dev_err(dev, "Failed to request reset gpio, error %d\n", error); return error; }
- fsleep(1000); /* Ensure long-enough reset pulse (minimum 10us). */
If the manufacturer specified that 10us is enough why do we want to wait 100 times longer?
Thanks.
On Wed, 5 Feb 2025 07:33:36 -0800 Dmitry Torokhov dmitry.torokhov@gmail.com wrote:
On Tue, Feb 04, 2025 at 02:01:00PM -0500, Hugo Villeneuve wrote:
From: Hugo Villeneuve hvilleneuve@dimonoff.com
The current reset pulse width is measured to be 5us on a Renesas RZ/G2L SOM. The manufacturer's minimum reset pulse width is specified as 10us.
Extend reset pulse width to make sure it is long enough on all platforms.
Also reword confusing comments about reset pin assertion.
Fixes: 5b0c03e24a06 ("Input: Add driver for Cypress Generation 5 touchscreen") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com
drivers/input/touchscreen/cyttsp5.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c index eafe5a9b8964..bb09e84d0e92 100644 --- a/drivers/input/touchscreen/cyttsp5.c +++ b/drivers/input/touchscreen/cyttsp5.c @@ -870,13 +870,16 @@ static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq, ts->input->phys = ts->phys; input_set_drvdata(ts->input, ts);
- /* Reset the gpio to be in a reset state */
- /* Assert gpio to be in a reset state */ ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(ts->reset_gpio)) { error = PTR_ERR(ts->reset_gpio); dev_err(dev, "Failed to request reset gpio, error %d\n", error); return error; }
- fsleep(1000); /* Ensure long-enough reset pulse (minimum 10us). */
If the manufacturer specified that 10us is enough why do we want to wait 100 times longer?
Hi, 10us would do fine. I simply put 1ms because it is then much easier to see the reset pulse on an oscilloscope when correlating it with other signals.
Hugo.
linux-stable-mirror@lists.linaro.org
-
Alistair -
Dmitry Torokhov -
Hugo Villeneuve