From f6b133a056e8fde7f4707e2874e204c7d5d671a2 Mon Sep 17 00:00:00 2001 From: Matthias Reichl Date: Sun, 18 Nov 2018 15:32:28 +0100 Subject: [PATCH] rpi-wm8804-soundcard: configure wm8804 clocks only on rate change This should avoid clicks when stopping and immediately afterwards starting a stream with the same samplerate as before. Signed-off-by: Matthias Reichl --- sound/soc/bcm/rpi-wm8804-soundcard.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/sound/soc/bcm/rpi-wm8804-soundcard.c +++ b/sound/soc/bcm/rpi-wm8804-soundcard.c @@ -64,6 +64,7 @@ struct snd_rpi_wm8804_drvdata { static struct gpio_desc *snd_clk44gpio; static struct gpio_desc *snd_clk48gpio; +static int wm8804_samplerate = 0; #define CLK_44EN_RATE 22579200UL #define CLK_48EN_RATE 24576000UL @@ -117,6 +118,12 @@ static int snd_rpi_wm8804_hw_params(stru struct wm8804_clk_cfg clk_cfg; int samplerate = params_rate(params); + if (samplerate == wm8804_samplerate) + return 0; + + /* clear until all clocks are setup properly */ + wm8804_samplerate = 0; + snd_rpi_wm8804_clk_cfg(samplerate, &clk_cfg); pr_debug("%s samplerate: %d mclk_freq: %u mclk_div: %u sysclk: %u\n", @@ -163,6 +170,8 @@ static int snd_rpi_wm8804_hw_params(stru return ret; } + wm8804_samplerate = samplerate; + /* set sampling frequency status bits */ snd_soc_component_update_bits(component, WM8804_SPDTX4, 0x0f, sampling_freq);