[PATCH] mmc: sdhci-pxav3: use managed clock enablement

[Rosen Penev]

Replace devm_clk_get() plus clk_prepare_enable() with the managed
variants devm_clk_get_enabled() and devm_clk_get_optional_enabled().
The core clock becomes optional, which removes the IS_ERR() guards
in runtime suspend/resume and lets devms unwind the clocks, so the
manual clk_disable_unprepare() calls in the probe error paths and
remove are dropped.

clk_prepare_enable() and friends are NULL safe, so no need to check if
the optional clock is present.

Also handle failures of clk_prepare_enable() in runtime resume instead
of ignoring them: a failed enable would leave controller register
accesses hitting unclocked hardware. Bail out before resuming the host
and unwind clk_io when enabling clk_core fails. This also drops the
now unused pltfm_host variable from remove().

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
 drivers/mmc/host/sdhci-pxav3.c | 42 +++++++++++++++-------------------
 1 file changed, 19 insertions(+), 23 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
index d082c4e21aa9..db9dfa92cb57 100644
--- a/drivers/mmc/host/sdhci-pxav3.c
+++ b/drivers/mmc/host/sdhci-pxav3.c
@@ -414,19 +414,18 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
 	pltfm_host = sdhci_priv(host);
 	pxa = sdhci_pltfm_priv(pltfm_host);
 
-	pxa->clk_io = devm_clk_get(dev, "io");
+	pxa->clk_io = devm_clk_get_enabled(dev, "io");
 	if (IS_ERR(pxa->clk_io))
-		pxa->clk_io = devm_clk_get(dev, NULL);
+		pxa->clk_io = devm_clk_get_enabled(dev, NULL);
 	if (IS_ERR(pxa->clk_io)) {
 		dev_err(dev, "failed to get io clock\n");
 		return PTR_ERR(pxa->clk_io);
 	}
 	pltfm_host->clk = pxa->clk_io;
-	clk_prepare_enable(pxa->clk_io);
 
-	pxa->clk_core = devm_clk_get(dev, "core");
-	if (!IS_ERR(pxa->clk_core))
-		clk_prepare_enable(pxa->clk_core);
+	pxa->clk_core = devm_clk_get_optional_enabled(dev, "core");
+	if (IS_ERR(pxa->clk_core))
+		return PTR_ERR(pxa->clk_core);
 
 	host->mmc->caps |= MMC_CAP_NEED_RSP_BUSY;
 	/* enable 1/8V DDR capable */
@@ -435,17 +434,17 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
 	if (of_device_is_compatible(np, "marvell,armada-380-sdhci")) {
 		ret = armada_38x_quirks(pdev, host);
 		if (ret < 0)
-			goto err_mbus_win;
+			return ret;
 		ret = mv_conf_mbus_windows(pdev, mv_mbus_dram_info());
 		if (ret < 0)
-			goto err_mbus_win;
+			return ret;
 	}
 
 	match = of_match_device(of_match_ptr(sdhci_pxav3_of_match), &pdev->dev);
 	if (match) {
 		ret = mmc_of_parse(host->mmc);
 		if (ret)
-			goto err_of_parse;
+			return ret;
 		sdhci_get_of_property(pdev);
 		pdata = pxav3_get_mmc_pdata(dev);
 		pdev->dev.platform_data = pdata;
@@ -500,27 +499,18 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
 err_add_host:
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
-err_of_parse:
-err_mbus_win:
-	clk_disable_unprepare(pxa->clk_io);
-	clk_disable_unprepare(pxa->clk_core);
 	return ret;
 }
 
 static void sdhci_pxav3_remove(struct platform_device *pdev)
 {
 	struct sdhci_host *host = platform_get_drvdata(pdev);
-	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
-	struct sdhci_pxa *pxa = sdhci_pltfm_priv(pltfm_host);
 
 	pm_runtime_get_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
 
 	sdhci_remove_host(host, 1);
-
-	clk_disable_unprepare(pxa->clk_io);
-	clk_disable_unprepare(pxa->clk_core);
 }
 
 static int sdhci_pxav3_suspend(struct device *dev)
@@ -561,8 +551,7 @@ static int sdhci_pxav3_runtime_suspend(struct device *dev)
 		mmc_retune_needed(host->mmc);
 
 	clk_disable_unprepare(pxa->clk_io);
-	if (!IS_ERR(pxa->clk_core))
-		clk_disable_unprepare(pxa->clk_core);
+	clk_disable_unprepare(pxa->clk_core);
 
 	return 0;
 }
@@ -572,10 +561,17 @@ static int sdhci_pxav3_runtime_resume(struct device *dev)
 	struct sdhci_host *host = dev_get_drvdata(dev);
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_pxa *pxa = sdhci_pltfm_priv(pltfm_host);
+	int ret;
 
-	clk_prepare_enable(pxa->clk_io);
-	if (!IS_ERR(pxa->clk_core))
-		clk_prepare_enable(pxa->clk_core);
+	ret = clk_prepare_enable(pxa->clk_io);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(pxa->clk_core);
+	if (ret) {
+		clk_disable_unprepare(pxa->clk_io);
+		return ret;
+	}
 
 	sdhci_runtime_resume_host(host, 0);
 	return 0;
-- 
2.55.0