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| author | Troy Kisky <troy.kisky@boundarydevices.com> | 2017-11-02 18:58:16 -0700 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2017-11-08 07:52:24 +0100 |
| commit | 05a03bf260e0480bfc0db91b1fdbc2115e3f193b (patch) | |
| tree | 129810da332509818fef7194a94595801b08981d /drivers/rtc/rtc-m41t80.c | |
| parent | 13bb1d78f2e372ec0d9b30489ac63768240140fc (diff) | |
| download | lwn-05a03bf260e0480bfc0db91b1fdbc2115e3f193b.tar.gz lwn-05a03bf260e0480bfc0db91b1fdbc2115e3f193b.zip | |
rtc: m41t80: remove unneeded checks from m41t80_sqw_set_rate
m41t80_sqw_set_rate will be called with the result from
m41t80_sqw_round_rate, so might as well make
m41t80_sqw_set_rate(n) same as
m41t80_sqw_set_rate(m41t80_sqw_round_rate(n))
As Russell King wrote[1],
"clk_round_rate() is supposed to tell you what you end up with if you
ask clk_set_rate() to set the exact same value you passed in - but
clk_round_rate() won't modify the hardware."
[1]
http://lists.infradead.org/pipermail/linux-arm-kernel/2012-January/080175.html
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc/rtc-m41t80.c')
| -rw-r--r-- | drivers/rtc/rtc-m41t80.c | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c index 96a606d5f6e6..c90fba3ed861 100644 --- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -490,17 +490,12 @@ static int m41t80_sqw_set_rate(struct clk_hw *hw, unsigned long rate, M41T80_REG_WDAY : M41T80_REG_SQW; int reg, ret, val = 0; - if (rate) { - if (!is_power_of_2(rate)) - return -EINVAL; - val = ilog2(rate); - if (val == ilog2(M41T80_SQW_MAX_FREQ)) - val = 1; - else if (val < (ilog2(M41T80_SQW_MAX_FREQ) - 1)) - val = ilog2(M41T80_SQW_MAX_FREQ) - val; - else - return -EINVAL; - } + if (rate >= M41T80_SQW_MAX_FREQ) + val = 1; + else if (rate >= M41T80_SQW_MAX_FREQ / 4) + val = 2; + else if (rate) + val = 15 - ilog2(rate); reg = i2c_smbus_read_byte_data(client, reg_sqw); if (reg < 0) |