Re: [PATCH 2/4] Input: goodix - Allow tweaking of configuration file dynamically

On Thu, 2016-10-27 at 11:58 -0500, Franklin S Cooper Jr wrote:

On 10/27/2016 05:33 AM, Bastien Nocera wrote:

quoted

On Thu, 2016-10-20 at 14:59 -0500, Franklin S Cooper Jr wrote:

quoted

Some goodix touchscreen controllers don't have the correct
configuration
firmware for the display panel it is attached to. Therefore,
settings
such
as touchscreen x and y size may need to be passed in via DT and
have
the
panel reprogrammed for the updated touchscreen resolution.

This patchset adds support for reading the current configuration
firmware
on the panel and allowing it to be modified and rewritten back to
the
device.

Currently this function is unused but later patches will make use
of
it.

Signed-off-by: Franklin S Cooper Jr <redacted>
---
 drivers/input/touchscreen/goodix.c | 28
++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/input/touchscreen/goodix.c

b/drivers/input/touchscreen/goodix.c
index a43c8ca..01e12f8 100644

--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c

@@ -478,6 +478,34 @@ static int goodix_get_gpio_config(struct

goodix_ts_data *ts)
 	return 0;
 }
 
+static void goodix_tweak_config(struct goodix_ts_data *ts)
+{
+	u8 config[GOODIX_CONFIG_MAX_LENGTH];
+	int error;
+	int raw_cfg_len;
+	u8 check_sum = 0;
+
+	raw_cfg_len = ts->cfg_len - 2;
+
+	error = goodix_i2c_read(ts->client,
GOODIX_REG_CONFIG_DATA,
+				config, ts->cfg_len);
+	if (error) {
+		dev_warn(&ts->client->dev,
+			 "Error reading config (%d), avoid
tweaking
config\n",
+			 error);
+		return;
+	}

Please add a placeholder comment here, to go along with the commit
message explanation.

You just want a comment here stating that changes to the firmware
should
be made here?

Yes, at least for this intermediary patch. You can remove in in
subsequent patches when it's clearer that this is where things go.

quoted

quoted

+	check_sum = goodix_calculate_checksum(ts->cfg_len,
config);
+
+	config[raw_cfg_len] = check_sum;
+	config[raw_cfg_len + 1] = 1;
+
+	error = goodix_send_cfg(ts, ts->cfg_len, config);
+	if (error)
+		dev_warn(&ts->client->dev,
+			 "Error writing config (%d)\n", error);
+}
 /**
  * goodix_read_config - Read the embedded configuration of the
panel
  *