mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its enablement

The I.MX SDHCI driver assumes that the frequency of the 'per' clock
can be obtained even on disabled clocks, which is not always the case.

According to 'clk_get_rate' documentation, it is only valid
once the clock source has been enabled.

Signed-off-by: Ciprian Costea <[email protected]>
Reviewed-by: Haibo Chen <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

Author: Ciprian Costea

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -1709,7 +1709,6 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 	}
 
 	pltfm_host->clk = imx_data->clk_per;
-	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
 	err = clk_prepare_enable(imx_data->clk_per);
 	if (err)
 		goto free_sdhci;
@@ -1720,6 +1719,13 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 	if (err)
 		goto disable_ipg_clk;
 
+	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
+	if (!pltfm_host->clock) {
+		dev_err(mmc_dev(host->mmc), "could not get clk rate\n");
+		err = -EINVAL;
+		goto disable_ahb_clk;
+	}
+
 	imx_data->pinctrl = devm_pinctrl_get(&pdev->dev);
 	if (IS_ERR(imx_data->pinctrl))
 		dev_warn(mmc_dev(host->mmc), "could not get pinctrl\n");