[PATCH 5/8] ASoC: rockchip: i2s-tdm: Fix clk_id usage in .set_sysclk()

luca.ceresoli
2022-09-07T14:24:23Z

From: Luca Ceresoli <luca.ceresoli@bootlin.com>

There are two problems with the second parameter of
rockchip_i2s_tdm_set_sysclk():

1. The second argument to a .set_sysclk() op is a clk_id, not a stream
index, so it is incorrect to compare it with SNDRV_PCM_STREAM_PLAYBACK.

Technically this code works correctly anyway because
SNDRV_PCM_STREAM_PLAYBACK is defined as 0, which is also the clk_id for
the mclk_tx as enforced by the device tree bindings. So this is a
formal error, not triggering incorrect behaviour.

2. The else branch will consider any nonzero value as "rx", while only
value 1 should be allowed for the mclk_rx clock. This does trigger
incorrect behaviour if passing clk_id not equal to 0 or 1.

Fix problem 1 by adding a new enum for the clock indexes as enforced in
device tree and replace accordingly:

* stream -> clk_id
* SNDRV_PCM_STREAM_PLAYBACK -> CLK_MCLK_TX (value 0)

Fix problem 2 by adding an 'else if' and returning error if clk_id is not 0
or 1.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
sound/soc/rockchip/rockchip_i2s_tdm.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/sound/soc/rockchip/rockchip_i2s_tdm.c b/sound/soc/rockchip/rockchip_i2s_tdm.c
index 2550bd2a5e78..4aa80fedb996 100644
--- a/sound/soc/rockchip/rockchip_i2s_tdm.c
+++ b/sound/soc/rockchip/rockchip_i2s_tdm.c
@@ -34,6 +34,9 @@
#define TRCM_TX 1
#define TRCM_RX 2

+/* Clock indexes as enforced by the DT bindings */
+enum { CLK_IDX_MCLK_TX, CLK_IDX_MCLK_RX };
+
struct txrx_config {
u32 addr;
u32 reg;
@@ -969,7 +972,7 @@ static int rockchip_i2s_tdm_trigger(struct snd_pcm_substream *substream,
return 0;
}

-static int rockchip_i2s_tdm_set_sysclk(struct snd_soc_dai *cpu_dai, int stream,
+static int rockchip_i2s_tdm_set_sysclk(struct snd_soc_dai *cpu_dai, int clk_id,
unsigned int freq, int dir)
{
struct rk_i2s_tdm_dev *i2s_tdm = to_info(cpu_dai);
@@ -978,15 +981,18 @@ static int rockchip_i2s_tdm_set_sysclk(struct snd_soc_dai *cpu_dai, int stream,
if (i2s_tdm->clk_trcm) {
i2s_tdm->mclk_tx_freq = freq;
i2s_tdm->mclk_rx_freq = freq;
+
+ dev_dbg(i2s_tdm->dev, "mclk freq: %u", freq);
} else {
- if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+ if (clk_id == CLK_IDX_MCLK_TX)
i2s_tdm->mclk_tx_freq = freq;
- else
+ else if (clk_id == CLK_IDX_MCLK_RX)
i2s_tdm->mclk_rx_freq = freq;
- }
+ else
+ return -ENOTSUPP;

- dev_dbg(i2s_tdm->dev, "The target mclk_%s freq is: %d\n",
- stream ? "rx" : "tx", freq);
+ dev_dbg(i2s_tdm->dev, "mclk[%d] freq: %u", clk_id, freq);
+ }

return 0;
}
--
2.34.1