ASoC: samsung: i2s: Ensure proper runtime PM state of I2S device

This patch adds calls to pm_runtime_get/put to ensure that any access to
I2S registers is done with proper (active) runtime PM state of I2S device.
Till now the driver enabled runtime PM, but didn't manage the state during
driver operation. The driver worked fine only because the runtime PM
callbacks managed device clock, which was enabled all the time because of
the additional enable call in the driver's probe function.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/samsung/i2s.c

@@ -477,6 +477,9 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
 	unsigned int rsrc_mask = 1 << i2s_regs->rclksrc_off;
 	u32 mod, mask, val = 0;
 	unsigned long flags;
+	int ret = 0;
+
+	pm_runtime_get_sync(dai->dev);
 
 	spin_lock_irqsave(i2s->lock, flags);
 	mod = readl(i2s->addr + I2SMOD);
@@ -501,7 +504,8 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
 					&& (mod & cdcon_mask))))) {
 			dev_err(&i2s->pdev->dev,
 				"%s:%d Other DAI busy\n", __func__, __LINE__);
-			return -EAGAIN;
+			ret = -EAGAIN;
+			goto err;
 		}
 
 		if (dir == SND_SOC_CLOCK_IN)
@@ -529,7 +533,7 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
 				} else {
 					i2s->rclk_srcrate =
 						clk_get_rate(i2s->op_clk);
-					return 0;
+					goto done;
 				}
 			}
 
@@ -540,8 +544,10 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
 				i2s->op_clk = clk_get(&i2s->pdev->dev,
 						"i2s_opclk0");
 
-			if (WARN_ON(IS_ERR(i2s->op_clk)))
-				return PTR_ERR(i2s->op_clk);
+			if (WARN_ON(IS_ERR(i2s->op_clk))) {
+				ret = PTR_ERR(i2s->op_clk);
+				goto err;
+			}
 
 			clk_prepare_enable(i2s->op_clk);
 			i2s->rclk_srcrate = clk_get_rate(i2s->op_clk);
@@ -555,12 +561,13 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
 				|| (clk_id && !(mod & rsrc_mask))) {
 			dev_err(&i2s->pdev->dev,
 				"%s:%d Other DAI busy\n", __func__, __LINE__);
-			return -EAGAIN;
+			ret = -EAGAIN;
+			goto err;
 		} else {
 			/* Call can't be on the active DAI */
 			i2s->op_clk = other->op_clk;
 			i2s->rclk_srcrate = other->rclk_srcrate;
-			return 0;
+			goto done;
 		}
 
 		if (clk_id == 1)
@@ -568,7 +575,8 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
 		break;
 	default:
 		dev_err(&i2s->pdev->dev, "We don't serve that!\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err;
 	}
 
 	spin_lock_irqsave(i2s->lock, flags);
@@ -576,8 +584,13 @@ static int i2s_set_sysclk(struct snd_soc_dai *dai,
 	mod = (mod & ~mask) | val;
 	writel(mod, i2s->addr + I2SMOD);
 	spin_unlock_irqrestore(i2s->lock, flags);
+done:
+	pm_runtime_put(dai->dev);
 
 	return 0;
+err:
+	pm_runtime_put(dai->dev);
+	return ret;
 }
 
 static int i2s_set_fmt(struct snd_soc_dai *dai,
@@ -646,6 +659,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
 		return -EINVAL;
 	}
 
+	pm_runtime_get_sync(dai->dev);
 	spin_lock_irqsave(i2s->lock, flags);
 	mod = readl(i2s->addr + I2SMOD);
 	/*
@@ -655,6 +669,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
 	if (any_active(i2s) &&
 		((mod & (sdf_mask | lrp_rlow | mod_slave)) != tmp)) {
 		spin_unlock_irqrestore(i2s->lock, flags);
+		pm_runtime_put(dai->dev);
 		dev_err(&i2s->pdev->dev,
 				"%s:%d Other DAI busy\n", __func__, __LINE__);
 		return -EAGAIN;
@@ -664,6 +679,7 @@ static int i2s_set_fmt(struct snd_soc_dai *dai,
 	mod |= tmp;
 	writel(mod, i2s->addr + I2SMOD);
 	spin_unlock_irqrestore(i2s->lock, flags);
+	pm_runtime_put(dai->dev);
 
 	return 0;
 }
@@ -675,6 +691,8 @@ static int i2s_hw_params(struct snd_pcm_substream *substream,
 	u32 mod, mask = 0, val = 0;
 	unsigned long flags;
 
+	WARN_ON(!pm_runtime_active(dai->dev));
+
 	if (!is_secondary(i2s))
 		mask |= (MOD_DC2_EN | MOD_DC1_EN);
 
@@ -763,6 +781,8 @@ static int i2s_startup(struct snd_pcm_substream *substream,
 	struct i2s_dai *other = get_other_dai(i2s);
 	unsigned long flags;
 
+	pm_runtime_get_sync(dai->dev);
+
 	spin_lock_irqsave(&lock, flags);
 
 	i2s->mode |= DAI_OPENED;
@@ -800,6 +820,8 @@ static void i2s_shutdown(struct snd_pcm_substream *substream,
 	i2s->bfs = 0;
 
 	spin_unlock_irqrestore(&lock, flags);
+
+	pm_runtime_put(dai->dev);
 }
 
 static int config_setup(struct i2s_dai *i2s)
@@ -874,6 +896,7 @@ static int i2s_trigger(struct snd_pcm_substream *substream,
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		pm_runtime_get_sync(dai->dev);
 		spin_lock_irqsave(i2s->lock, flags);
 
 		if (config_setup(i2s)) {
@@ -902,6 +925,7 @@ static int i2s_trigger(struct snd_pcm_substream *substream,
 		}
 
 		spin_unlock_irqrestore(i2s->lock, flags);
+		pm_runtime_put(dai->dev);
 		break;
 	}
 
@@ -916,13 +940,16 @@ static int i2s_set_clkdiv(struct snd_soc_dai *dai,
 
 	switch (div_id) {
 	case SAMSUNG_I2S_DIV_BCLK:
+		pm_runtime_get_sync(dai->dev);
 		if ((any_active(i2s) && div && (get_bfs(i2s) != div))
 			|| (other && other->bfs && (other->bfs != div))) {
+			pm_runtime_put(dai->dev);
 			dev_err(&i2s->pdev->dev,
 				"%s:%d Other DAI busy\n", __func__, __LINE__);
 			return -EAGAIN;
 		}
 		i2s->bfs = div;
+		pm_runtime_put(dai->dev);
 		break;
 	default:
 		dev_err(&i2s->pdev->dev,
@@ -941,6 +968,8 @@ i2s_delay(struct snd_pcm_substream *substream, struct snd_soc_dai *dai)
 	snd_pcm_sframes_t delay;
 	const struct samsung_i2s_variant_regs *i2s_regs = i2s->variant_regs;
 
+	WARN_ON(!pm_runtime_active(dai->dev));
+
 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
 		delay = FIC_RXCOUNT(reg);
 	else if (is_secondary(i2s))
@@ -984,6 +1013,8 @@ static int samsung_i2s_dai_probe(struct snd_soc_dai *dai)
 	struct i2s_dai *other = get_other_dai(i2s);
 	unsigned long flags;
 
+	pm_runtime_get_sync(dai->dev);
+
 	if (is_secondary(i2s)) { /* If this is probe on the secondary DAI */
 		snd_soc_dai_init_dma_data(dai, &other->sec_dai->dma_playback,
 					   NULL);
@@ -1016,6 +1047,7 @@ static int samsung_i2s_dai_probe(struct snd_soc_dai *dai)
 	if (!is_opened(other))
 		i2s_set_sysclk(dai, SAMSUNG_I2S_CDCLK,
 				0, SND_SOC_CLOCK_IN);
+	pm_runtime_put(dai->dev);
 
 	return 0;
 }
@@ -1025,6 +1057,8 @@ static int samsung_i2s_dai_remove(struct snd_soc_dai *dai)
 	struct i2s_dai *i2s = snd_soc_dai_get_drvdata(dai);
 	unsigned long flags;
 
+	pm_runtime_get_sync(dai->dev);
+
 	if (!is_secondary(i2s)) {
 		if (i2s->quirks & QUIRK_NEED_RSTCLR) {
 			spin_lock_irqsave(i2s->lock, flags);
@@ -1033,6 +1067,8 @@ static int samsung_i2s_dai_remove(struct snd_soc_dai *dai)
 		}
 	}
 
+	pm_runtime_put(dai->dev);
+
 	return 0;
 }
 
@@ -1322,7 +1358,7 @@ static int samsung_i2s_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(&pdev->dev, pri_dai);
 
-
+	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
 	ret = i2s_register_clock_provider(pdev);
@@ -1345,10 +1381,12 @@ static int samsung_i2s_remove(struct platform_device *pdev)
 	pri_dai->sec_dai = NULL;
 	sec_dai->pri_dai = NULL;
 
+	pm_runtime_get_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
 	i2s_unregister_clock_provider(pdev);
 	clk_disable_unprepare(pri_dai->clk);
+	pm_runtime_put_noidle(&pdev->dev);
 
 	return 0;
 }