ufs: Add freq-table-hz property for UFS device

Add freq-table-hz propery for UFS device to keep track of
<min max> frequencies supported by UFS clocks.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

3 files changed, 43 insertions, 19 deletions

diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
index fb1234e0532c..53579197eca2 100644
--- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
+++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
@@ -26,11 +26,11 @@ Optional properties:
 - clocks                : List of phandle and clock specifier pairs
 - clock-names           : List of clock input name strings sorted in the same
                           order as the clocks property.
-- max-clock-frequency-hz : List of maximum operating frequency stored in the same
-                           order as the clocks property. If this property is not
-                           defined or a value in the array is "0" then it is assumed
-                           that the frequency is set by the parent clock or a
-                           fixed rate clock source.
+- freq-table-hz         : Array of <min max> operating frequencies stored in the same
+                          order as the clocks property. If this property is not
+                          defined or a value in the array is "0" then it is assumed
+                          that the frequency is set by the parent clock or a
+                          fixed rate clock source.
 
 Note: If above properties are not defined it can be assumed that the supply
 regulators or clocks are always on.
@@ -53,5 +53,5 @@ Example:
 
                 clocks = <&core 0>, <&ref 0>, <&iface 0>;
                 clock-names = "core_clk", "ref_clk", "iface_clk";
-                max-clock-frequency-hz = <100000000 19200000 0>;
+                freq-table-hz = <100000000 200000000>, <0 0>, <0 0>;
         };
diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 2482bbac3681..8adf067ff019 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -63,6 +63,8 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
         char *name;
         u32 *clkfreq = NULL;
         struct ufs_clk_info *clki;
+        int len = 0;
+        size_t sz = 0;
 
         if (!np)
                 goto out;
@@ -82,39 +84,59 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
         if (cnt <= 0)
                 goto out;
 
-        clkfreq = kzalloc(cnt * sizeof(*clkfreq), GFP_KERNEL);
+        if (!of_get_property(np, "freq-table-hz", &len)) {
+                dev_info(dev, "freq-table-hz property not specified\n");
+                goto out;
+        }
+
+        if (len <= 0)
+                goto out;
+
+        sz = len / sizeof(*clkfreq);
+        if (sz != 2 * cnt) {
+                dev_err(dev, "%s len mismatch\n", "freq-table-hz");
+                ret = -EINVAL;
+                goto out;
+        }
+
+        clkfreq = devm_kzalloc(dev, sz * sizeof(*clkfreq),
+                        GFP_KERNEL);
         if (!clkfreq) {
+                dev_err(dev, "%s: no memory\n", "freq-table-hz");
                 ret = -ENOMEM;
-                dev_err(dev, "%s: memory alloc failed\n", __func__);
                 goto out;
         }
 
-        ret = of_property_read_u32_array(np,
-                        "max-clock-frequency-hz", clkfreq, cnt);
+        ret = of_property_read_u32_array(np, "freq-table-hz",
+                        clkfreq, sz);
         if (ret && (ret != -EINVAL)) {
-                dev_err(dev, "%s: invalid max-clock-frequency-hz property, %d\n",
-                                __func__, ret);
-                goto out;
+                dev_err(dev, "%s: error reading array %d\n",
+                                "freq-table-hz", ret);
+                goto free_clkfreq;
         }
 
-        for (i = 0; i < cnt; i++) {
+        for (i = 0; i < sz; i += 2) {
                 ret = of_property_read_string_index(np,
-                                "clock-names", i, (const char **)&name);
+                                "clock-names", i/2, (const char **)&name);
                 if (ret)
-                        goto out;
+                        goto free_clkfreq;
 
                 clki = devm_kzalloc(dev, sizeof(*clki), GFP_KERNEL);
                 if (!clki) {
                         ret = -ENOMEM;
-                        goto out;
+                        goto free_clkfreq;
                 }
 
-                clki->max_freq = clkfreq[i];
+                clki->min_freq = clkfreq[i];
+                clki->max_freq = clkfreq[i+1];
                 clki->name = kstrdup(name, GFP_KERNEL);
+                dev_dbg(dev, "%s: min %u max %u name %s\n", "freq-table-hz",
+                                clki->min_freq, clki->max_freq, clki->name);
                 list_add_tail(&clki->list, &hba->clk_list_head);
         }
-out:
+free_clkfreq:
         kfree(clkfreq);
+out:
         return ret;
 }
 
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 29d34d3aa5ee..ac72a6daf50e 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -209,6 +209,7 @@ struct ufs_dev_cmd {
  * @clk: clock node
  * @name: clock name
  * @max_freq: maximum frequency supported by the clock
+ * @min_freq: min frequency that can be used for clock scaling
  * @enabled: variable to check against multiple enable/disable
  */
 struct ufs_clk_info {
@@ -216,6 +217,7 @@ struct ufs_clk_info {
         struct clk *clk;
         const char *name;
         u32 max_freq;
+        u32 min_freq;
         bool enabled;
 };