Messages in this thread | | | Date | Tue, 07 May 2013 12:40:56 +0200 | From | Marek Belisko <> | Subject | Re: [PATCH 2/2] clk: si5351: Powerdown output when clock rate is 0. |
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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.belisko@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
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