The ili9882t is a TDDI IC ((Touch with Display Driver)). It requires the
panel reset gpio to be high before i2c commands. Use a longer delay in
post_power_delay_ms to ensure the poweron sequence.

Signed-off-by: Cong Yang <yangcong5@huaqin.corp-partner.google.com>
---
 drivers/hid/i2c-hid/i2c-hid-of-elan.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/hid/i2c-hid/i2c-hid-of-elan.c b/drivers/hid/i2c-hid/i2c-hid-of-elan.c
index 76ddc8be1cbb..dd2435270e73 100644
--- a/drivers/hid/i2c-hid/i2c-hid-of-elan.c
+++ b/drivers/hid/i2c-hid/i2c-hid-of-elan.c
@@ -105,8 +105,15 @@ static const struct elan_i2c_hid_chip_data elan_ekth6915_chip_data = {
 	.hid_descriptor_address = 0x0001,
 };
 
+static const struct elan_i2c_hid_chip_data ilitek_ili9882t_chip_data = {
+	.post_power_delay_ms = 200,
+	.post_gpio_reset_delay_ms = 180,
+	.hid_descriptor_address = 0x0001,
+};
+
 static const struct of_device_id elan_i2c_hid_of_match[] = {
 	{ .compatible = "elan,ekth6915", .data = &elan_ekth6915_chip_data },
+	{ .compatible = "ilitek,ili9882t", .data = &ilitek_ili9882t_chip_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, elan_i2c_hid_of_match);
-- 
2.25.1

Hi,

On Fri, May 19, 2023 at 10:07 PM Cong Yang
<yangcong5@huaqin.corp-partner.google.com> wrote:
>
> The ili9882t is a TDDI IC ((Touch with Display Driver)). It requires the
> panel reset gpio to be high before i2c commands. Use a longer delay in
> post_power_delay_ms to ensure the poweron sequence.
>
> Signed-off-by: Cong Yang <yangcong5@huaqin.corp-partner.google.com>
> ---
>  drivers/hid/i2c-hid/i2c-hid-of-elan.c | 7 +++++++
>  1 file changed, 7 insertions(+)

This seems OK to me. The one thing I'd also do is to update the
Kconfig description to say that this driver is also used for Ilitek. I
think it's fine to keep the symbol name as I2C_HID_OF_ELAN but just
change the description.

-Doug

On Mon, May 22, 2023 at 08:27:38AM -0700, Doug Anderson wrote:
> Hi,
> 
> On Fri, May 19, 2023 at 10:07 PM Cong Yang
> <yangcong5@huaqin.corp-partner.google.com> wrote:
> >
> > The ili9882t is a TDDI IC ((Touch with Display Driver)). It requires the
> > panel reset gpio to be high before i2c commands. Use a longer delay in
> > post_power_delay_ms to ensure the poweron sequence.
> >
> > Signed-off-by: Cong Yang <yangcong5@huaqin.corp-partner.google.com>
> > ---
> >  drivers/hid/i2c-hid/i2c-hid-of-elan.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> 
> This seems OK to me. The one thing I'd also do is to update the
> Kconfig description to say that this driver is also used for Ilitek. I
> think it's fine to keep the symbol name as I2C_HID_OF_ELAN but just
> change the description.

Does ilitek have the same set of regulators, etc, or is it only the
timing? I'd probably make it a separate mini-driver...

Thanks.

-- 
Dmitry