Messages in this thread | | | Subject | Re: [PATCH v1] Input: elants_i2c: Add Elan touchscreen support | From | Oliver Neukum <> | Date | Thu, 20 Nov 2014 11:31:30 +0100 |
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> +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.
> +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@suse.de>
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