scsi: ufs: core: Store min and max clk freq from OPP table

JIRA: https://issues.redhat.com/browse/RHEL-79078

commit 77a6725
Author: Nitin Rawat <quic_nitirawa@quicinc.com>
Date:   Fri Dec 8 18:43:31 2023 +0530

    scsi: ufs: core: Store min and max clk freq from OPP table

    OPP support added by commit 72208eb ("scsi: ufs: core: Add support for
    parsing OPP") doesn't update the min_freq and max_freq of each clock in
    'struct ufs_clk_info'.

    But these values are used by the host drivers internally for controller
    configuration. When the OPP support is enabled in devicetree, these values
    will be 0, causing boot issues on the respective platforms.

    So add support to parse the min_freq and max_freq of all clocks while
    parsing the OPP table.

    Fixes: 72208eb ("scsi: ufs: core: Add support for parsing OPP")
    Co-developed-by: Manish Pandey <quic_mapa@quicinc.com>
    Signed-off-by: Manish Pandey <quic_mapa@quicinc.com>
    Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
    Link: https://lore.kernel.org/r/20231208131331.12596-1-quic_nitirawa@quicinc.com
    Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
    Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: Radu Rendec <rrendec@redhat.com>

Author: rrendec

drivers/ufs/host/ufshcd-pltfrm.c

@@ -8,6 +8,7 @@
  *	Vinayak Holikatti <h.vinayak@samsung.com>
  */
 
+#include <linux/clk.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
@@ -208,6 +209,55 @@ static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
 	}
 }
 
+/**
+ * ufshcd_parse_clock_min_max_freq  - Parse MIN and MAX clocks freq
+ * @hba: per adapter instance
+ *
+ * This function parses MIN and MAX frequencies of all clocks required
+ * by the host drivers.
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+static int ufshcd_parse_clock_min_max_freq(struct ufs_hba *hba)
+{
+	struct list_head *head = &hba->clk_list_head;
+	struct ufs_clk_info *clki;
+	struct dev_pm_opp *opp;
+	unsigned long freq;
+	u8 idx = 0;
+
+	list_for_each_entry(clki, head, list) {
+		if (!clki->name)
+			continue;
+
+		clki->clk = devm_clk_get(hba->dev, clki->name);
+		if (IS_ERR(clki->clk))
+			continue;
+
+		/* Find Max Freq */
+		freq = ULONG_MAX;
+		opp = dev_pm_opp_find_freq_floor_indexed(hba->dev, &freq, idx);
+		if (IS_ERR(opp)) {
+			dev_err(hba->dev, "Failed to find OPP for MAX frequency\n");
+			return PTR_ERR(opp);
+		}
+		clki->max_freq = dev_pm_opp_get_freq_indexed(opp, idx);
+		dev_pm_opp_put(opp);
+
+		/* Find Min Freq */
+		freq = 0;
+		opp = dev_pm_opp_find_freq_ceil_indexed(hba->dev, &freq, idx);
+		if (IS_ERR(opp)) {
+			dev_err(hba->dev, "Failed to find OPP for MIN frequency\n");
+			return PTR_ERR(opp);
+		}
+		clki->min_freq = dev_pm_opp_get_freq_indexed(opp, idx++);
+		dev_pm_opp_put(opp);
+	}
+
+	return 0;
+}
+
 static int ufshcd_parse_operating_points(struct ufs_hba *hba)
 {
 	struct device *dev = hba->dev;
@@ -274,6 +324,10 @@ static int ufshcd_parse_operating_points(struct ufs_hba *hba)
 		return ret;
 	}
 
+	ret = ufshcd_parse_clock_min_max_freq(hba);
+	if (ret)
+		return ret;
+
 	hba->use_pm_opp = true;
 
 	return 0;