[PATCH/RESEND V5 14/17] scsi: ufs: Add freq-table-hz property for UFS device

Dolev Raviv
2014-09-24T15:15:12Z

From: Sahitya Tummala <stummala@codeaurora.org>

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>

diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
index fb1234e..5357919 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 2482bba..8adf067 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 29d34d3..ac72a6d 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;
};