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mmc: sdhci-bcm-kona: Add basic use of clocks

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Enable the external clock needed by the host controller during the
probe and disable it during the remove.

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
This commit is contained in:
Tim Kryger 2013-12-05 11:20:41 -08:00 committed by Chris Ball
parent 8d94b54d99
commit a6492c0207
1 changed files with 35 additions and 2 deletions
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37
drivers/mmc/host/sdhci-bcm-kona.c
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@ -54,6 +54,7 @@
struct sdhci_bcm_kona_dev { struct sdhci_bcm_kona_dev {
struct mutex write_lock; /* protect back to back writes */ struct mutex write_lock; /* protect back to back writes */
struct clk *external_clk;
}; };
@ -257,6 +258,24 @@ static int sdhci_bcm_kona_probe(struct platform_device *pdev)
goto err_pltfm_free; 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", dev_dbg(dev, "non-removable=%c\n",
(host->mmc->caps & MMC_CAP_NONREMOVABLE) ? 'Y' : 'N'); (host->mmc->caps & MMC_CAP_NONREMOVABLE) ? 'Y' : 'N');
dev_dbg(dev, "cd_gpio %c, wp_gpio %c\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); ret = sdhci_bcm_kona_sd_reset(host);
if (ret) if (ret)
goto err_pltfm_free; goto err_clk_disable;
sdhci_bcm_kona_sd_init(host); sdhci_bcm_kona_sd_init(host);
@ -307,6 +326,9 @@ err_remove_host:
err_reset: err_reset:
sdhci_bcm_kona_sd_reset(host); sdhci_bcm_kona_sd_reset(host);
err_clk_disable:
clk_disable_unprepare(kona_dev->external_clk);
err_pltfm_free: err_pltfm_free:
sdhci_pltfm_free(pdev); sdhci_pltfm_free(pdev);
@ -316,7 +338,18 @@ err_pltfm_free:
static int __exit sdhci_bcm_kona_remove(struct platform_device *pdev) static int __exit sdhci_bcm_kona_remove(struct platform_device *pdev)
{ {
return sdhci_pltfm_unregister(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 = (readl(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
sdhci_remove_host(host, dead);
clk_disable_unprepare(kona_dev->external_clk);
sdhci_pltfm_free(pdev);
return 0;
} }
static struct platform_driver sdhci_bcm_kona_driver = { static struct platform_driver sdhci_bcm_kona_driver = {