From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932076AbbIXWO2 (ORCPT ); Thu, 24 Sep 2015 18:14:28 -0400 Received: from ns.gsystem.sk ([62.176.172.50]:53619 "EHLO gsystem.sk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754392AbbIXWO1 (ORCPT ); Thu, 24 Sep 2015 18:14:27 -0400 From: Ondrej Zary To: Krzysztof Helt Cc: Tomi Valkeinen , linux-fbdev@vger.kernel.org, Kernel development list Subject: [PATCH v2 1/2] fb_ddc: Allow I2C adapters without SCL read capability Date: Fri, 25 Sep 2015 00:14:13 +0200 Message-Id: <1443132854-31786-1-git-send-email-linux@rainbow-software.org> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org i2c-algo-bit allows I2C adapters without SCL read capability to work but fb_ddc_read fails to work on them. Fix fb_ddc_read to work with I2C adapters not capable of reading SCL. Signed-off-by: Ondrej Zary --- drivers/video/fbdev/core/fb_ddc.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/drivers/video/fbdev/core/fb_ddc.c b/drivers/video/fbdev/core/fb_ddc.c index 94322cc..8bf5f2f 100644 --- a/drivers/video/fbdev/core/fb_ddc.c +++ b/drivers/video/fbdev/core/fb_ddc.c @@ -67,13 +67,17 @@ unsigned char *fb_ddc_read(struct i2c_adapter *adapter) msleep(13); algo_data->setscl(algo_data->data, 1); - for (j = 0; j < 5; j++) { - msleep(10); - if (algo_data->getscl(algo_data->data)) - break; + if (algo_data->getscl) { + for (j = 0; j < 5; j++) { + msleep(10); + if (algo_data->getscl(algo_data->data)) + break; + } + if (j == 5) + continue; + } else { + udelay(algo_data->udelay); } - if (j == 5) - continue; algo_data->setsda(algo_data->data, 0); msleep(15); @@ -89,10 +93,14 @@ unsigned char *fb_ddc_read(struct i2c_adapter *adapter) msleep(15); algo_data->setscl(algo_data->data, 1); - for (j = 0; j < 10; j++) { - msleep(10); - if (algo_data->getscl(algo_data->data)) - break; + if (algo_data->getscl) { + for (j = 0; j < 10; j++) { + msleep(10); + if (algo_data->getscl(algo_data->data)) + break; + } + } else { + udelay(algo_data->udelay); } algo_data->setsda(algo_data->data, 1); -- Ondrej Zary