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From: Marco Felsch <m.felsch@pengutronix.de>
To: robh+dt@kernel.org, andriy.shevchenko@linux.intel.com,
	dmitry.torokhov@gmail.com, bparrot@ti.com,
	andy.shevchenko@gmail.com, simon.budig@kernelconcepts.de,
	hdegoede@redhat.com, fcooper@ti.com, mripard@kernel.org,
	alexandre.belloni@bootlin.com, shawnguo@kernel.org
Cc: devicetree@vger.kernel.org, kernel@pengutronix.de,
	linux-input@vger.kernel.org
Subject: [PATCH v2 5/5] Input: edt-ft5x06 - improve power management operations
Date: Wed, 27 Nov 2019 13:09:48 +0100
Message-ID: <20191127120948.22251-6-m.felsch@pengutronix.de> (raw)
In-Reply-To: <20191127120948.22251-1-m.felsch@pengutronix.de>

It is possible to bring the device into a deep sleep state. To exit this
state the reset or wakeup pin must be toggeled as documented in [1].
Because of the poor documentation I used the several downstream kernels
[2] and other applications notes [3] to indentify the related registers.

Furthermore I added the support to disable the device completely. This is
the most effective power-saving mechanism. Disabling the device don't
change the suspend logic because the hibernate mode needs a hardware
reset anyway.

[1] https://www.newhavendisplay.com/appnotes/datasheets/touchpanel/FT5x26.pdf
[2] https://github.com/linux-sunxi/linux-sunxi/blob/sunxi-3.4/drivers/input/touchscreen/ft5x_ts.c
    https://github.com/Pablito2020/focaltech-touch-driver/blob/master/ft5336_driver.c
[3] https://www.newhavendisplay.com/appnotes/datasheets/touchpanel/FT5x16_registers.pdf

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
v2:
- adapt commit message
- don't return errors during suspend/resume
- replace dev_err() by dev_warn()
- add support to disable the regulator too

 drivers/input/touchscreen/edt-ft5x06.c | 49 ++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index 8d2ec7947f0e..0bdd3440f684 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -39,6 +39,9 @@
 #define WORK_REGISTER_NUM_X		0x33
 #define WORK_REGISTER_NUM_Y		0x34
 
+#define PMOD_REGISTER_ACTIVE		0x00
+#define PMOD_REGISTER_HIBERNATE		0x03
+
 #define M09_REGISTER_THRESHOLD		0x80
 #define M09_REGISTER_GAIN		0x92
 #define M09_REGISTER_OFFSET		0x93
@@ -54,6 +57,7 @@
 
 #define WORK_REGISTER_OPMODE		0x3c
 #define FACTORY_REGISTER_OPMODE		0x01
+#define PMOD_REGISTER_OPMODE		0xa5
 
 #define TOUCH_EVENT_DOWN		0x00
 #define TOUCH_EVENT_UP			0x01
@@ -1235,9 +1239,29 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
 static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
+	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
+	int ret;
 
-	if (device_may_wakeup(dev))
+	if (device_may_wakeup(dev)) {
 		enable_irq_wake(client->irq);
+		return 0;
+	}
+
+	/*
+	 * Hibernate mode requires reset or wake signal to recover to active
+	 * state.
+	 */
+	if (!tsdata->wake_gpio && !tsdata->reset_gpio)
+		return 0;
+
+	ret = edt_ft5x06_register_write(tsdata, PMOD_REGISTER_OPMODE,
+					PMOD_REGISTER_HIBERNATE);
+	if (ret)
+		dev_warn(dev, "Failed to set hibernate mode\n");
+
+	ret = regulator_disable(tsdata->vcc);
+	if (ret)
+		dev_warn(dev, "Failed to disable vcc\n");
 
 	return 0;
 }
@@ -1245,9 +1269,30 @@ static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
 static int __maybe_unused edt_ft5x06_ts_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
+	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
+	int ret;
 
-	if (device_may_wakeup(dev))
+	if (device_may_wakeup(dev)) {
 		disable_irq_wake(client->irq);
+		return 0;
+	}
+
+	ret = regulator_enable(tsdata->vcc);
+	if (ret)
+		dev_warn(dev, "Failed to enable vcc\n");
+
+	/* Recover from hibernate mode if hardware supports it */
+	if (tsdata->wake_gpio) {
+		gpiod_set_value_cansleep(tsdata->wake_gpio, 0);
+		usleep_range(5000, 6000);
+		gpiod_set_value_cansleep(tsdata->wake_gpio, 1);
+		msleep(300);
+	} else if (tsdata->reset_gpio) {
+		gpiod_set_value_cansleep(tsdata->reset_gpio, 1);
+		usleep_range(5000, 6000);
+		gpiod_set_value_cansleep(tsdata->reset_gpio, 0);
+		msleep(300);
+	}
 
 	return 0;
 }
-- 
2.20.1


  parent reply index

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-27 12:09 [PATCH v2 0/5] EDT-FT5x06 improvements Marco Felsch
2019-11-27 12:09 ` [PATCH v2 1/5] Input: edt-ft5x06: work around first register access error Marco Felsch
2019-12-02 17:58   ` Dmitry Torokhov
2019-12-03  8:15     ` Marco Felsch
2019-11-27 12:09 ` [PATCH v2 2/5] Input: edt-ft5x06 - alphabetical include reorder Marco Felsch
2019-11-27 12:09 ` [PATCH v2 3/5] dt-bindings: Input: edt-ft5x06 - document wakeup-source capability Marco Felsch
2019-12-05 21:15   ` Rob Herring
2019-11-27 12:09 ` [PATCH v2 4/5] Input: edt-ft5x06 - make wakeup-source switchable Marco Felsch
2019-12-02 18:00   ` Dmitry Torokhov
2019-12-10  8:36     ` Marco Felsch
2019-11-27 12:09 ` Marco Felsch [this message]
2019-11-27 12:59   ` [PATCH v2 5/5] Input: edt-ft5x06 - improve power management operations Andy Shevchenko
2019-11-27 13:06     ` Marco Felsch
2019-11-27 14:32       ` Andy Shevchenko
2019-11-27 17:25         ` Marco Felsch
2019-11-27 18:06           ` Andy Shevchenko
2019-12-02 18:04   ` Dmitry Torokhov
2019-12-10  8:43     ` Marco Felsch
2019-11-27 17:10 ` [PATCH v2 0/5] EDT-FT5x06 improvements Andy Shevchenko
2019-11-27 17:14 ` Andy Shevchenko
2019-11-27 17:25   ` Marco Felsch

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