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.
+ 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",
--
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