Hi Laurent,
Den 11.08.2019 15.35, skrev Laurent Pinchart:
Hi Noralf,
On Sun, Aug 11, 2019 at 03:19:13PM +0200, Noralf Trønnes wrote:
Sam,
Den 11.08.2019 01.10, skrev Laurent Pinchart:
This panel is used on the Gumstix Overo Palo35.
The code is based on the omapdrm-specific panel-lgphilips-lb035q02 driver.
Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Reviewed-by: Sam Ravnborg sam@ravnborg.org
<snip>
diff --git a/drivers/gpu/drm/panel/panel-lg-lb035q02.c b/drivers/gpu/drm/panel/panel-lg-lb035q02.c
<snip>
+static int lb035q02_write(struct lb035q02_device *lcd, u16 reg, u16 val) +{
- struct spi_message msg;
- struct spi_transfer index_xfer = {
.len = 3,.cs_change = 1,- };
- struct spi_transfer value_xfer = {
.len = 3,- };
- u8 buffer[16];
- spi_message_init(&msg);
- /* register index */
- buffer[0] = 0x70;
- buffer[1] = 0x00;
- buffer[2] = reg & 0x7f;
- index_xfer.tx_buf = buffer;
- spi_message_add_tail(&index_xfer, &msg);
- /* register value */
- buffer[4] = 0x72;
- buffer[5] = val >> 8;
- buffer[6] = val;
- value_xfer.tx_buf = buffer + 4;
- spi_message_add_tail(&value_xfer, &msg);
- return spi_sync(lcd->spi, &msg);
+}
Just a note to Sam: This is the same spi protocol that the ili9325 controller on the hy28b panel uses.
I remembered that I have experimented with a regmap implementation: https://github.com/notro/tinydrm/blob/master/tinydrm-ili9325.c#L191
That's useful information, thanks. The controller seems different though, the limited information available in https://www.beyondinfinite.com/lcd/Library/LG-Philips/LB035Q02.pdf doesn't match the registers from https://github.com/notro/tinydrm/blob/master/fb_ili9325.c.
I've seen several controllers that use this protocol, and one that had a different start byte configuration. The details unfortunately is lost in time, it's been a while since I worked on these controllers.
Noralf.