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thermal: rockchip: use the usleep_range instead of udelay

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Documentation/timers/timers-howto.txt recommends to use
usleep_range on delays > 10usec.
The usleep_range indeed reduces CPU load, since the udelay will busy wait
for enough loop cycles to achieve the desired delay.

Fixes commit b06c52db39fd ("thermal: rockchip:
handle the power sequence for tsadc controller").

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Suggested-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
This commit is contained in:
Caesar Wang 2016-05-03 10:23:50 +08:00 committed by Eduardo Valentin
parent 678065d5b7
commit 2fe5c1b045
1 changed files with 2 additions and 2 deletions
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4
drivers/thermal/rockchip_thermal.c
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@ -547,10 +547,10 @@ static void rk_tsadcv3_initialize(struct regmap *grf, void __iomem *regs,
regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_ON);
mdelay(10);
regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_OFF);
udelay(100); /* The spec note says at least 15 us */
usleep_range(15, 100); /* The spec note says at least 15 us */
regmap_write(grf, GRF_SARADC_TESTBIT, GRF_SARADC_TESTBIT_ON);
regmap_write(grf, GRF_TSADC_TESTBIT_H, GRF_TSADC_TESTBIT_H_ON);
udelay(200); /* The spec note says at least 90 us */
usleep_range(90, 200); /* The spec note says at least 90 us */
}
if (tshut_polarity == TSHUT_HIGH_ACTIVE)