On 05/07/2013 12:07 PM, Sebastian Hesselbarth wrote:
On 05/07/2013 10:14 AM, Marek Belisko wrote:
When rate is 0 powerdown clock output.

Signed-off-by: Marek Belisko<marek.beli...@streamunlimited.com>
---
  drivers/clk/clk-si5351.c |   32 +++++++++++++++++++-------------
  1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c
index a8fc0f4..e254e76 100644
--- a/drivers/clk/clk-si5351.c
+++ b/drivers/clk/clk-si5351.c
@@ -1042,20 +1042,22 @@ static int si5351_clkout_set_rate(struct
clk_hw *hw, unsigned long rate,
      struct si5351_hw_data *hwdata =
          container_of(hw, struct si5351_hw_data, hw);
      unsigned long new_rate, new_err, err;
-    unsigned char rdiv;
+    unsigned char rdiv, pdn = 0;

      /* round to closed rdiv */
      rdiv = SI5351_OUTPUT_CLK_DIV_1;
-    new_rate = parent_rate;
-    err = abs(new_rate - rate);
-    do {
-        new_rate>>= 1;
-        new_err = abs(new_rate - rate);
-        if (new_err>  err || rdiv == SI5351_OUTPUT_CLK_DIV_128)
-            break;
-        rdiv++;
-        err = new_err;
-    } while (1);
+    if (rate) {
+        new_rate = parent_rate;

Marek,

initalizing pdn to SI5351_CLK_POWERDOWN and skip (with goto) to
powerup/down call on zero rate will save us a level of indention here.
OK will fix and resubmit in v2. Thanks.

+        err = abs(new_rate - rate);
+        do {
+            new_rate>>= 1;
+            new_err = abs(new_rate - rate);
+            if (new_err>  err || rdiv == SI5351_OUTPUT_CLK_DIV_128)
+                break;
+            rdiv++;
+            err = new_err;
+        } while (1);

of course, pdn should be set to 0 here.

+    }

      /* write output divider */
      switch (hwdata->num) {
@@ -1075,9 +1077,13 @@ static int si5351_clkout_set_rate(struct clk_hw
*hw, unsigned long rate,
                  rdiv<<  SI5351_OUTPUT_CLK_DIV_SHIFT);
      }

-    /* powerup clkout */
+    /* when rate is 0 powerdown output */
+    if (rate == 0)
+        pdn = SI5351_CLK_POWERDOWN;
+
+    /* powerup/down clkout */
      si5351_set_bits(hwdata->drvdata, SI5351_CLK0_CTRL + hwdata->num,
-            SI5351_CLK_POWERDOWN, 0);
+            SI5351_CLK_POWERDOWN, pdn);

      dev_dbg(&hwdata->drvdata->client->dev,
          "%s - %s: rdiv = %u, parent_rate = %lu, rate = %lu\n",



marek
--
Marek Belisko

Software Developer
StreamUnlimited Engineering GmbH
Gutheil Schodergasse 8-12
A-1100 Vienna, Austria

Office: +421 267200087

e-mail: marek.beli...@streamunlimited.com
http://www.streamunlimited.com

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