Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760005AbbBIIe4 (ORCPT ); Mon, 9 Feb 2015 03:34:56 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:44750 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759954AbbBIIey (ORCPT ); Mon, 9 Feb 2015 03:34:54 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Nelson , Fabio Estevam , Mark Brown Subject: [PATCH 3.10 13/17] ASoC: sgtl5000: add delay before first I2C access Date: Mon, 9 Feb 2015 16:33:40 +0800 Message-Id: <20150209083040.917214408@linuxfoundation.org> X-Mailer: git-send-email 2.3.0 In-Reply-To: <20150209083039.240170510@linuxfoundation.org> References: <20150209083039.240170510@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1435 Lines: 44 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Nelson 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: Greg Kroah-Hartman --- sound/soc/codecs/sgtl5000.c | 3 +++ 1 file changed, 3 insertions(+) --- a/sound/soc/codecs/sgtl5000.c +++ b/sound/soc/codecs/sgtl5000.c @@ -1242,6 +1242,9 @@ static int sgtl5000_enable_regulators(st /* wait for all power rails bring up */ udelay(10); + /* Need 8 clocks before I2C accesses */ + udelay(1); + /* read chip information */ reg = snd_soc_read(codec, SGTL5000_CHIP_ID); if (((reg & SGTL5000_PARTID_MASK) >> SGTL5000_PARTID_SHIFT) != -- 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/