From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Nelson , Mark Brown , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 73/80] ASoC: sgtl5000: add delay before first I2C access Date: Thu, 19 Mar 2015 15:36:01 -0700 Message-Id: <1426804568-2907-74-git-send-email-kamal@canonical.com> In-Reply-To: <1426804568-2907-1-git-send-email-kamal@canonical.com> References: <1426804568-2907-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.13.11-ckt17 -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: Kamal Mostafa --- 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 b76c6b6..ba73f83 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) -- 1.9.1