Hi Oliver: -----Original Message----- From: Oliver Neukum [mailto:oneukum@xxxxxxx] Sent: Thursday, November 20, 2014 6:32 PM To: Dmitry Torokhov Cc: scott; linux-kernel@xxxxxxxxxxxxxxx; linux-input@xxxxxxxxxxxxxxx; 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 <oneukum@xxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
