diff mbox series

[v5,07/10] input: elants: support 0x66 reply opcode for reporting touches

Message ID 02dc25c5851e50d77bc707a2e1b44caf9d6354eb.1587923061.git.mirq-linux@rere.qmqm.pl (mailing list archive)
State Superseded
Headers show
Series input: elants: Support Asus TF300T touchscreen | expand

Commit Message

Michał Mirosław April 26, 2020, 5:47 p.m. UTC 
From: Dmitry Osipenko <digetx@gmail.com>

eKTF3624 touchscreen firmware uses two variants of the reply opcodes for
reporting touch events: one is 0x63 (used by older firmware) and other is
0x66 (used by newer firmware). The 0x66 variant is equal to 0x63 of
eKTH3500, while 0x63 needs small adjustment of the touch pressure value.

Nexus 7 tablet device has eKTF3624 touchscreen and it uses 0x66 opcode for
reporting touch events, let's support it now. Other devices, eg. ASUS TF300T,
use 0x63.

Note: CMD_HEADER_REK is used for replying to calibration requests, it has
the same 0x66 opcode number which eKTF3624 uses for reporting touches.
The calibration replies are handled separately from the the rest of the
commands in the driver by entering into ELAN_WAIT_RECALIBRATION state
and thus this change shouldn't change the old behavior.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 drivers/input/touchscreen/elants_i2c.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

Dmitry Torokhov May 18, 2020, 4:05 a.m. UTC | #1 
On Sun, Apr 26, 2020 at 07:47:52PM +0200, Michał Mirosław wrote:
> From: Dmitry Osipenko <digetx@gmail.com>
> 
> eKTF3624 touchscreen firmware uses two variants of the reply opcodes for
> reporting touch events: one is 0x63 (used by older firmware) and other is
> 0x66 (used by newer firmware). The 0x66 variant is equal to 0x63 of
> eKTH3500, while 0x63 needs small adjustment of the touch pressure value.
> 
> Nexus 7 tablet device has eKTF3624 touchscreen and it uses 0x66 opcode for
> reporting touch events, let's support it now. Other devices, eg. ASUS TF300T,
> use 0x63.
> 
> Note: CMD_HEADER_REK is used for replying to calibration requests, it has
> the same 0x66 opcode number which eKTF3624 uses for reporting touches.
> The calibration replies are handled separately from the the rest of the
> commands in the driver by entering into ELAN_WAIT_RECALIBRATION state
> and thus this change shouldn't change the old behavior.

Is it possible to know what format a device will use by querying it at
probe time?

Thanks.
Dmitry Osipenko May 18, 2020, 9:10 a.m. UTC | #2 
18.05.2020 07:05, Dmitry Torokhov пишет:
> On Sun, Apr 26, 2020 at 07:47:52PM +0200, Michał Mirosław wrote:
>> From: Dmitry Osipenko <digetx@gmail.com>
>>
>> eKTF3624 touchscreen firmware uses two variants of the reply opcodes for
>> reporting touch events: one is 0x63 (used by older firmware) and other is
>> 0x66 (used by newer firmware). The 0x66 variant is equal to 0x63 of
>> eKTH3500, while 0x63 needs small adjustment of the touch pressure value.
>>
>> Nexus 7 tablet device has eKTF3624 touchscreen and it uses 0x66 opcode for
>> reporting touch events, let's support it now. Other devices, eg. ASUS TF300T,
>> use 0x63.
>>
>> Note: CMD_HEADER_REK is used for replying to calibration requests, it has
>> the same 0x66 opcode number which eKTF3624 uses for reporting touches.
>> The calibration replies are handled separately from the the rest of the
>> commands in the driver by entering into ELAN_WAIT_RECALIBRATION state
>> and thus this change shouldn't change the old behavior.
> 
> Is it possible to know what format a device will use by querying it at
> probe time?

I guess only somebody from Elan could answer this question. AFAIK,
neither touchscreen firmware sources nor technical documentation aren't
publicly available.

Downstream kernel driver is the only source of information in our case
and it does the same thing as we do in this patch.
diff mbox series

Patch

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index 88294bc491e8..7eb74eb832d7 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -61,6 +61,15 @@ 
 #define QUEUE_HEADER_NORMAL	0X63
 #define QUEUE_HEADER_WAIT	0x64
 
+/*
+ * Depending on firmware version, eKTF3624 touchscreens may utilize one of
+ * these opcodes for the touch events: 0x63 and 0x66. The 0x63 is used by
+ * older firmware version and differs from 0x66 such that touch pressure
+ * value needs to be adjusted. The 0x66 opcode of newer firmware is equal
+ * to 0x63 of eKTH3500.
+ */
+#define QUEUE_HEADER_NORMAL2	0x66
+
 /* Command header definition */
 #define CMD_HEADER_WRITE	0x54
 #define CMD_HEADER_READ		0x53
@@ -1057,7 +1066,6 @@  static irqreturn_t elants_i2c_irq(int irq, void *_dev)
 		switch (ts->buf[FW_HDR_TYPE]) {
 		case CMD_HEADER_HELLO:
 		case CMD_HEADER_RESP:
-		case CMD_HEADER_REK:
 			break;
 
 		case QUEUE_HEADER_WAIT:
@@ -1077,6 +1085,7 @@  static irqreturn_t elants_i2c_irq(int irq, void *_dev)
 			break;
 
 		case QUEUE_HEADER_NORMAL:
+		case QUEUE_HEADER_NORMAL2:
 			report_count = ts->buf[FW_HDR_COUNT];
 			if (report_count == 0 || report_count > 3) {
 				dev_err(&client->dev,