Hi Oliver:
-----Original Message-----
From: Oliver Neukum [mailto:[email protected]]
Sent: Thursday, November 20, 2014 6:32 PM
To: Dmitry Torokhov
Cc: scott; [email protected]; [email protected]; Vincent
Wang; Jeff Chuang; Benson Leung; Benjamin Tissoires; Henrik Rydberg; David
Herrmann
Subject: Re: [PATCH v1] Input: elants_i2c: Add Elan touchscreen support
> +static int elants_i2c_sw_reset(struct i2c_client *client) {
> + const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
> + int error;
> +
> + error = elants_i2c_send(client, soft_rst_cmd,
> + sizeof(soft_rst_cmd));
> + if (error) {
> + dev_err(&client->dev, "software reset failed: %d\n",
> error);
> + return error;
> + }
> +
> + /*
> + * We should wait at least 10 msec (but no more than 40)
> before
> + * sending fastboot or IAP command to the device.
> + */
> + msleep(30);
If timing is critical in both ways, you should take our guarantee if sufficient
sleep. I suggest you sleep 11msecs.
Sorry, this is our firmware tricky but it should be sleep longer than 30ms.
Actually 70ms.
(Dmitry, I need to modify this delay time to 70ms. Sorry for the changed over
and over again;
because we consider big sensor solution which need to use more ICs and
need more longer delay)
thanks,
Scott
> +static int elants_i2c_initialize(struct elants_data *ts) {
> + struct i2c_client *client = ts->client;
> + int error, retry_cnt;
> + const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
> + const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
> + u8 buf[HEADER_SIZE];
> +
Strictly speaking you should disable preemption here.
> + for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
> + error = elants_i2c_sw_reset(client);
> + if (error) {
> + /* Continue initializing if it's the last try
> */
> + if (retry_cnt < MAX_RETRIES - 1)
> + continue;
> + }
Regards
Oliver
--
Oliver Neukum <[email protected]>
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