[PATCH 6/6] mmc: sdhci-bcm-kona: Add basic use of clocks
From: Tim Kryger <hidden>
Date: 2013-10-03 20:14:07
Also in:
linux-devicetree, linux-mmc, lkml
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, secure digital host controller interface (sdhci) driver, the rest · Maintainers:
Ulf Hansson, Adrian Hunter, Linus Torvalds
Enable the external clock needed by the host controller during the probe and disable it during the remove. Signed-off-by: Tim Kryger <redacted> Reviewed-by: Markus Mayer <redacted> Reviewed-by: Matt Porter <redacted> --- drivers/mmc/host/sdhci-bcm-kona.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci-bcm-kona.c b/drivers/mmc/host/sdhci-bcm-kona.c
index 85472d3..91db099 100644
--- a/drivers/mmc/host/sdhci-bcm-kona.c
+++ b/drivers/mmc/host/sdhci-bcm-kona.c@@ -54,6 +54,7 @@ struct sdhci_bcm_kona_dev { struct mutex write_lock; /* protect back to back writes */ + struct clk *external_clk; };
@@ -252,11 +253,29 @@ static int sdhci_bcm_kona_probe(struct platform_device *pdev) mmc_of_parse(host->mmc); if (!host->mmc->f_max) { - dev_err(&pdev->dev, "Missing max-freq for SDHCI cfg\n"); + dev_err(dev, "Missing max-freq for SDHCI cfg\n"); ret = -ENXIO; goto err_pltfm_free; } + /* Get and enable the external clock */ + kona_dev->external_clk = devm_clk_get(dev, NULL); + if (IS_ERR(kona_dev->external_clk)) { + dev_err(dev, "Failed to get external clock\n"); + ret = PTR_ERR(kona_dev->external_clk); + goto err_pltfm_free; + } + + if (clk_set_rate(kona_dev->external_clk, host->mmc->f_max) != 0) { + dev_err(dev, "Failed to set rate external clock\n"); + goto err_pltfm_free; + } + + if (clk_prepare_enable(kona_dev->external_clk) != 0) { + dev_err(dev, "Failed to enable external clock\n"); + goto err_pltfm_free; + } + dev_dbg(dev, "non-removable=%c\n", (host->mmc->caps & MMC_CAP_NONREMOVABLE) ? 'Y' : 'N'); dev_dbg(dev, "cd_gpio %c, wp_gpio %c\n",
@@ -271,7 +290,7 @@ static int sdhci_bcm_kona_probe(struct platform_device *pdev) ret = sdhci_bcm_kona_sd_reset(host); if (ret) - goto err_pltfm_free; + goto err_clk_disable; sdhci_bcm_kona_sd_init(host);
@@ -307,6 +326,9 @@ err_remove_host: err_reset: sdhci_bcm_kona_sd_reset(host); +err_clk_disable: + clk_disable_unprepare(kona_dev->external_clk); + err_pltfm_free: sdhci_pltfm_free(pdev);
@@ -317,6 +339,8 @@ err_pltfm_free: static int __exit sdhci_bcm_kona_remove(struct platform_device *pdev) { struct sdhci_host *host = platform_get_drvdata(pdev); + struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host); + struct sdhci_bcm_kona_dev *kona_dev = sdhci_pltfm_priv(pltfm_priv); int dead; u32 scratch;
@@ -326,6 +350,8 @@ static int __exit sdhci_bcm_kona_remove(struct platform_device *pdev) dead = 1; sdhci_remove_host(host, dead); + clk_disable_unprepare(kona_dev->external_clk); + sdhci_free_host(host); return 0;
--
1.8.0.1