From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sugar Zhang Subject: [PATCH v1 1/4] ASoC: rockchip: i2s: add a delay before i2s clear Date: Fri, 9 Jun 2017 16:52:46 +0800 Message-ID: <1496998369-30556-2-git-send-email-sugar.zhang@rock-chips.com> References: <1496998369-30556-1-git-send-email-sugar.zhang@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from regular1.263xmail.com (regular1.263xmail.com [211.150.99.130]) by alsa0.perex.cz (Postfix) with ESMTP id 7AD6D2675B6 for ; Fri, 9 Jun 2017 10:56:52 +0200 (CEST) In-Reply-To: <1496998369-30556-1-git-send-email-sugar.zhang@rock-chips.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: heiko@sntech.de, broonie@kernel.org Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Takashi Iwai , Liam Girdwood , Sugar Zhang , linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org List-Id: alsa-devel@alsa-project.org in order to guarantee i2s lrck signal integrity, when i2s stop, need at least one lrck cycle to ensure signal integrity. the max delay time is when lrck is 8khz, the delay time is 125us(1/8khz), using udelay(150) with a 25us margin. Signed-off-by: Sugar Zhang --- sound/soc/rockchip/rockchip_i2s.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c index 974915c..f548433 100644 --- a/sound/soc/rockchip/rockchip_i2s.c +++ b/sound/soc/rockchip/rockchip_i2s.c @@ -116,6 +116,7 @@ static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on) I2S_XFER_TXS_STOP | I2S_XFER_RXS_STOP); + udelay(150); regmap_update_bits(i2s->regmap, I2S_CLR, I2S_CLR_TXC | I2S_CLR_RXC, I2S_CLR_TXC | I2S_CLR_RXC); @@ -162,6 +163,7 @@ static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on) I2S_XFER_TXS_STOP | I2S_XFER_RXS_STOP); + udelay(150); regmap_update_bits(i2s->regmap, I2S_CLR, I2S_CLR_TXC | I2S_CLR_RXC, I2S_CLR_TXC | I2S_CLR_RXC); -- 1.9.1