Re: [PATCH AUTOSEL 5.15 12/28] ASoC: rockchip: i2s: switch BCLK to GPIO

From: Chen-Yu Tsai
Date: Thu Jul 14 2022 - 00:43:06 EST


Hi,

On Thu, Jul 14, 2022 at 12:25 PM Sasha Levin <sashal@xxxxxxxxxx> wrote:
>
> From: Judy Hsiao <judyhsiao@xxxxxxxxxxxx>
>
> [ Upstream commit a5450aba737dae3ee1a64b282e609d8375d6700c ]
>
> We discoverd that the state of BCLK on, LRCLK off and SD_MODE on
> may cause the speaker melting issue. Removing LRCLK while BCLK
> is present can cause unexpected output behavior including a large
> DC output voltage as described in the Max98357a datasheet.
>
> In order to:
> 1. prevent BCLK from turning on by other component.
> 2. keep BCLK and LRCLK being present at the same time
>
> This patch switches BCLK to GPIO func before LRCLK output, and
> configures BCLK func back during LRCLK is output.
>
> Without this fix, BCLK is turned on 11 ms earlier than LRCK by the
> da7219.
> With this fix, BCLK is turned on only 0.4 ms earlier than LRCK by
> the rockchip codec.
>
> Signed-off-by: Judy Hsiao <judyhsiao@xxxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20220615045643.3137287-1-judyhsiao@xxxxxxxxxxxx
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

Please drop this one from all stable branches. It caused more problems
than it fixed and will be reverted for 5.19 [1]. The same patch, along
with a proper follow-up fix, are queued up for 5.20.

Regards
ChenYu

[1] https://lore.kernel.org/alsa-devel/20220713130451.31481-1-broonie@xxxxxxxxxx/

> ---
> sound/soc/rockchip/rockchip_i2s.c | 160 ++++++++++++++++++++++++------
> 1 file changed, 129 insertions(+), 31 deletions(-)
>
> diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c
> index 2880a0537646..bde0ceaf100d 100644
> --- a/sound/soc/rockchip/rockchip_i2s.c
> +++ b/sound/soc/rockchip/rockchip_i2s.c
> @@ -13,6 +13,7 @@
> #include <linux/of_gpio.h>
> #include <linux/of_device.h>
> #include <linux/clk.h>
> +#include <linux/pinctrl/consumer.h>
> #include <linux/pm_runtime.h>
> #include <linux/regmap.h>
> #include <linux/spinlock.h>
> @@ -55,8 +56,40 @@ struct rk_i2s_dev {
> const struct rk_i2s_pins *pins;
> unsigned int bclk_ratio;
> spinlock_t lock; /* tx/rx lock */
> + struct pinctrl *pinctrl;
> + struct pinctrl_state *bclk_on;
> + struct pinctrl_state *bclk_off;
> };
>
> +static int i2s_pinctrl_select_bclk_on(struct rk_i2s_dev *i2s)
> +{
> + int ret = 0;
> +
> + if (!IS_ERR(i2s->pinctrl) && !IS_ERR_OR_NULL(i2s->bclk_on))
> + ret = pinctrl_select_state(i2s->pinctrl,
> + i2s->bclk_on);
> +
> + if (ret)
> + dev_err(i2s->dev, "bclk enable failed %d\n", ret);
> +
> + return ret;
> +}
> +
> +static int i2s_pinctrl_select_bclk_off(struct rk_i2s_dev *i2s)
> +{
> +
> + int ret = 0;
> +
> + if (!IS_ERR(i2s->pinctrl) && !IS_ERR_OR_NULL(i2s->bclk_off))
> + ret = pinctrl_select_state(i2s->pinctrl,
> + i2s->bclk_off);
> +
> + if (ret)
> + dev_err(i2s->dev, "bclk disable failed %d\n", ret);
> +
> + return ret;
> +}
> +
> static int i2s_runtime_suspend(struct device *dev)
> {
> struct rk_i2s_dev *i2s = dev_get_drvdata(dev);
> @@ -93,38 +126,49 @@ static inline struct rk_i2s_dev *to_info(struct snd_soc_dai *dai)
> return snd_soc_dai_get_drvdata(dai);
> }
>
> -static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
> +static int rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
> {
> unsigned int val = 0;
> int retry = 10;
> + int ret = 0;
>
> spin_lock(&i2s->lock);
> if (on) {
> - regmap_update_bits(i2s->regmap, I2S_DMACR,
> - I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_ENABLE);
> + ret = regmap_update_bits(i2s->regmap, I2S_DMACR,
> + I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_ENABLE);
> + if (ret < 0)
> + goto end;
>
> - regmap_update_bits(i2s->regmap, I2S_XFER,
> - I2S_XFER_TXS_START | I2S_XFER_RXS_START,
> - I2S_XFER_TXS_START | I2S_XFER_RXS_START);
> + ret = regmap_update_bits(i2s->regmap, I2S_XFER,
> + I2S_XFER_TXS_START | I2S_XFER_RXS_START,
> + I2S_XFER_TXS_START | I2S_XFER_RXS_START);
> + if (ret < 0)
> + goto end;
>
> i2s->tx_start = true;
> } else {
> i2s->tx_start = false;
>
> - regmap_update_bits(i2s->regmap, I2S_DMACR,
> - I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_DISABLE);
> + ret = regmap_update_bits(i2s->regmap, I2S_DMACR,
> + I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_DISABLE);
> + if (ret < 0)
> + goto end;
>
> if (!i2s->rx_start) {
> - regmap_update_bits(i2s->regmap, I2S_XFER,
> - I2S_XFER_TXS_START |
> - I2S_XFER_RXS_START,
> - I2S_XFER_TXS_STOP |
> - I2S_XFER_RXS_STOP);
> + ret = regmap_update_bits(i2s->regmap, I2S_XFER,
> + I2S_XFER_TXS_START |
> + I2S_XFER_RXS_START,
> + I2S_XFER_TXS_STOP |
> + I2S_XFER_RXS_STOP);
> + if (ret < 0)
> + goto end;
>
> udelay(150);
> - regmap_update_bits(i2s->regmap, I2S_CLR,
> - I2S_CLR_TXC | I2S_CLR_RXC,
> - I2S_CLR_TXC | I2S_CLR_RXC);
> + ret = regmap_update_bits(i2s->regmap, I2S_CLR,
> + I2S_CLR_TXC | I2S_CLR_RXC,
> + I2S_CLR_TXC | I2S_CLR_RXC);
> + if (ret < 0)
> + goto end;
>
> regmap_read(i2s->regmap, I2S_CLR, &val);
>
> @@ -139,44 +183,57 @@ static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
> }
> }
> }
> +end:
> spin_unlock(&i2s->lock);
> + if (ret < 0)
> + dev_err(i2s->dev, "lrclk update failed\n");
> +
> + return ret;
> }
>
> -static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
> +static int rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
> {
> unsigned int val = 0;
> int retry = 10;
> + int ret = 0;
>
> spin_lock(&i2s->lock);
> if (on) {
> - regmap_update_bits(i2s->regmap, I2S_DMACR,
> + ret = regmap_update_bits(i2s->regmap, I2S_DMACR,
> I2S_DMACR_RDE_ENABLE, I2S_DMACR_RDE_ENABLE);
> + if (ret < 0)
> + goto end;
>
> - regmap_update_bits(i2s->regmap, I2S_XFER,
> + ret = regmap_update_bits(i2s->regmap, I2S_XFER,
> I2S_XFER_TXS_START | I2S_XFER_RXS_START,
> I2S_XFER_TXS_START | I2S_XFER_RXS_START);
> + if (ret < 0)
> + goto end;
>
> i2s->rx_start = true;
> } else {
> i2s->rx_start = false;
>
> - regmap_update_bits(i2s->regmap, I2S_DMACR,
> + ret = regmap_update_bits(i2s->regmap, I2S_DMACR,
> I2S_DMACR_RDE_ENABLE, I2S_DMACR_RDE_DISABLE);
> + if (ret < 0)
> + goto end;
>
> if (!i2s->tx_start) {
> - regmap_update_bits(i2s->regmap, I2S_XFER,
> + ret = regmap_update_bits(i2s->regmap, I2S_XFER,
> I2S_XFER_TXS_START |
> I2S_XFER_RXS_START,
> I2S_XFER_TXS_STOP |
> I2S_XFER_RXS_STOP);
> -
> + if (ret < 0)
> + goto end;
> udelay(150);
> - regmap_update_bits(i2s->regmap, I2S_CLR,
> + ret = regmap_update_bits(i2s->regmap, I2S_CLR,
> I2S_CLR_TXC | I2S_CLR_RXC,
> I2S_CLR_TXC | I2S_CLR_RXC);
> -
> + if (ret < 0)
> + goto end;
> regmap_read(i2s->regmap, I2S_CLR, &val);
> -
> /* Should wait for clear operation to finish */
> while (val) {
> regmap_read(i2s->regmap, I2S_CLR, &val);
> @@ -188,7 +245,12 @@ static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
> }
> }
> }
> +end:
> spin_unlock(&i2s->lock);
> + if (ret < 0)
> + dev_err(i2s->dev, "lrclk update failed\n");
> +
> + return ret;
> }
>
> static int rockchip_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
> @@ -426,17 +488,26 @@ static int rockchip_i2s_trigger(struct snd_pcm_substream *substream,
> case SNDRV_PCM_TRIGGER_RESUME:
> case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
> - rockchip_snd_rxctrl(i2s, 1);
> + ret = rockchip_snd_rxctrl(i2s, 1);
> else
> - rockchip_snd_txctrl(i2s, 1);
> + ret = rockchip_snd_txctrl(i2s, 1);
> + /* Do not turn on bclk if lrclk open fails. */
> + if (ret < 0)
> + return ret;
> + i2s_pinctrl_select_bclk_on(i2s);
> break;
> case SNDRV_PCM_TRIGGER_SUSPEND:
> case SNDRV_PCM_TRIGGER_STOP:
> case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> - if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
> - rockchip_snd_rxctrl(i2s, 0);
> - else
> - rockchip_snd_txctrl(i2s, 0);
> + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
> + if (!i2s->tx_start)
> + i2s_pinctrl_select_bclk_off(i2s);
> + ret = rockchip_snd_rxctrl(i2s, 0);
> + } else {
> + if (!i2s->rx_start)
> + i2s_pinctrl_select_bclk_off(i2s);
> + ret = rockchip_snd_txctrl(i2s, 0);
> + }
> break;
> default:
> ret = -EINVAL;
> @@ -737,6 +808,33 @@ static int rockchip_i2s_probe(struct platform_device *pdev)
> }
>
> i2s->bclk_ratio = 64;
> + i2s->pinctrl = devm_pinctrl_get(&pdev->dev);
> + if (IS_ERR(i2s->pinctrl))
> + dev_err(&pdev->dev, "failed to find i2s pinctrl\n");
> +
> + i2s->bclk_on = pinctrl_lookup_state(i2s->pinctrl,
> + "bclk_on");
> + if (IS_ERR_OR_NULL(i2s->bclk_on))
> + dev_err(&pdev->dev, "failed to find i2s default state\n");
> + else
> + dev_dbg(&pdev->dev, "find i2s bclk state\n");
> +
> + i2s->bclk_off = pinctrl_lookup_state(i2s->pinctrl,
> + "bclk_off");
> + if (IS_ERR_OR_NULL(i2s->bclk_off))
> + dev_err(&pdev->dev, "failed to find i2s gpio state\n");
> + else
> + dev_dbg(&pdev->dev, "find i2s bclk_off state\n");
> +
> + i2s_pinctrl_select_bclk_off(i2s);
> +
> + i2s->playback_dma_data.addr = res->start + I2S_TXDR;
> + i2s->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + i2s->playback_dma_data.maxburst = 4;
> +
> + i2s->capture_dma_data.addr = res->start + I2S_RXDR;
> + i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + i2s->capture_dma_data.maxburst = 4;
>
> dev_set_drvdata(&pdev->dev, i2s);
>
> --
> 2.35.1
>
>
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