Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755901AbaKTMZY (ORCPT ); Thu, 20 Nov 2014 07:25:24 -0500 Received: from emcscan.emc.com.tw ([192.72.220.5]:36600 "EHLO emcscan.emc.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750953AbaKTMZW convert rfc822-to-8bit (ORCPT ); Thu, 20 Nov 2014 07:25:22 -0500 From: =?UTF-8?B?RUxBTiDlionlmInpp78=?= To: "'Oliver Neukum'" , "'Dmitry Torokhov'" Cc: , , "'Vincent Wang'" , "'Jeff Chuang'" , "'Benson Leung'" , "'Benjamin Tissoires'" , "'Henrik Rydberg'" , "'David Herrmann'" References: <1388146515-19481-1-git-send-email-scott.liu@emc.com.tw> <20141120081113.GA37534@dtor-ws> <1416479490.28599.13.camel@linux-0dmf.site> In-Reply-To: <1416479490.28599.13.camel@linux-0dmf.site> Subject: RE: [PATCH v1] Input: elants_i2c: Add Elan touchscreen support Date: Thu, 20 Nov 2014 20:25:15 +0800 Message-ID: <000001d004bd$0ad90830$208b1890$@emc.com.tw> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQGPAtNJZnsxghQAUQdBW7YNhjLKyQLlfmrAAacox4acxwy7AA== Content-Language: zh-tw Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Oliver: -----Original Message----- From: Oliver Neukum [mailto:oneukum@suse.de] Sent: Thursday, November 20, 2014 6:32 PM To: Dmitry Torokhov Cc: scott; linux-kernel@vger.kernel.org; linux-input@vger.kernel.org; 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/