Re: [PATCH] mmc: sdhci-of-arasan: Add support to request the "gate" clock
From: Adrian Hunter
Date: Thu Mar 02 2023 - 06:09:57 EST
On 23/02/23 16:14, Swati Agarwal wrote:
> Add support to read the optional "gate" clock property and request the
> clock which will be used to ungate the DLL clock.
>
> For Xilinx platforms which has DLL module, dll clock must be
> ungated/enabled when SD controller operates at higher frequencies like 50
> MHz, 100 MHz and 200 MHz. This will be done by explicitly requesting gate
> clock from the driver.
>
> Signed-off-by: Swati Agarwal <swati.agarwal@xxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-of-arasan.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 4eebbf801b41..1fd7528c14fc 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -1870,6 +1870,7 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
> int ret;
> struct device_node *node;
> struct clk *clk_xin;
> + struct clk *clk_dll;
> struct sdhci_host *host;
> struct sdhci_pltfm_host *pltfm_host;
> struct device *dev = &pdev->dev;
> @@ -1943,6 +1944,12 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
> goto clk_dis_ahb;
> }
>
> + clk_dll = devm_clk_get_optional_enabled(dev, "gate");
> + if (IS_ERR(clk_dll)) {
> + ret = dev_err_probe(dev, PTR_ERR(clk_dll), "failed to get dll clk\n");
> + goto clk_disable_all;
> + }
> +
> if (of_property_read_bool(np, "xlnx,fails-without-test-cd"))
> sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_FORCE_CDTEST;
>