On 4/27/22 11:08, Kamal Dasu wrote:
From: Al Cooper <alcooperx@xxxxxxxxx>
The 72116B0 has improved SDIO controllers that allow the max clock
rate to be increased from a max of 100MHz to a max of 150MHz. The
driver will need to get the clock and increase it's default rate
and override the caps register, that still indicates a max of 100MHz.
The new clock will be named "sdio_freq" in the DT node's "clock-names"
list. The driver will use a DT property, "clock-frequency", to
enable this functionality and will get the actual rate in MHz
from the property to allow various speeds to be requested.
Signed-off-by: Al Cooper <alcooperx@xxxxxxxxx>
Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
---
drivers/mmc/host/sdhci-brcmstb.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
index 683d0c685748..51a23e9f4535 100644
--- a/drivers/mmc/host/sdhci-brcmstb.c
+++ b/drivers/mmc/host/sdhci-brcmstb.c
@@ -250,6 +250,7 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
struct sdhci_pltfm_host *pltfm_host;
const struct of_device_id *match;
struct sdhci_brcmstb_priv *priv;
+ u32 base_clock_hz = 0;
struct sdhci_host *host;
struct resource *iomem;
struct clk *clk;
@@ -330,6 +331,30 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
if (match_priv->flags & BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT)
host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;
+ /* Change the base clock frequency if the DT property exists */
+ if (device_property_read_u32(&pdev->dev, "max-frequency",
+ &base_clock_hz) == 0) {
+ struct clk *master_clk;
+ u32 actual_clock_mhz;
+
+ master_clk = devm_clk_get(&pdev->dev, "sdio_freq");
+ if (IS_ERR(master_clk)) {
+ dev_warn(&pdev->dev,
+ "Clock for \"sdio_freq\" was not found\n");
+ } else {
+ clk_set_rate(master_clk, base_clock_hz);
It seems to me that you should enable the clock before getting its rate,
otherwise this may not return a valid rate. You might also consider
reducing the indentation a little bit by using a label.
--
Florian
