Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965394AbbBQLws (ORCPT ); Tue, 17 Feb 2015 06:52:48 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:39857 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756943AbbBQLfO (ORCPT ); Tue, 17 Feb 2015 06:35:14 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eric Nelson , Mark Brown , Jiri Slaby Subject: [PATCH 3.12 071/122] ASoC: sgtl5000: add delay before first I2C access Date: Tue, 17 Feb 2015 12:34:18 +0100 Message-Id: X-Mailer: git-send-email 2.2.2 In-Reply-To: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> References: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1476 Lines: 46 From: Eric Nelson 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 58cc9c9a175885bbf6bae3acf18233d0a8229a84 upstream. To quote from section 1.3.1 of the data sheet: The SGTL5000 has an internal reset that is deasserted 8 SYS_MCLK cycles after all power rails have been brought up. After this time, communication can start ... 1.0us represents 8 SYS_MCLK cycles at the minimum 8.0 MHz SYS_MCLK. Signed-off-by: Eric Nelson Reviewed-by: Fabio Estevam Signed-off-by: Mark Brown Signed-off-by: Jiri Slaby --- sound/soc/codecs/sgtl5000.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c index b76c6b619227..ba73f832e455 100644 --- a/sound/soc/codecs/sgtl5000.c +++ b/sound/soc/codecs/sgtl5000.c @@ -1550,6 +1550,9 @@ static int sgtl5000_i2c_probe(struct i2c_client *client, if (ret) return ret; + /* Need 8 clocks before I2C accesses */ + udelay(1); + /* read chip information */ ret = regmap_read(sgtl5000->regmap, SGTL5000_CHIP_ID, ®); if (ret) -- 2.2.2 -- 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/