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Subject[PATCH v3 5/8] mmc: sdhci-bcm-kona: Add basic use of clocks
Date
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>
---
drivers/mmc/host/sdhci-bcm-kona.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-bcm-kona.c b/drivers/mmc/host/sdhci-bcm-kona.c
index 85472d3..bffbb40 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;
};


@@ -257,6 +258,24 @@ static int sdhci_bcm_kona_probe(struct platform_device *pdev)
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



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