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b997e3edca
At least on cherrytrail, the update bit will never go low when the
enabled bit is not set.
This causes the backlight on my cube iwork8 air tablet to never turn on
again after being turned off because in the pwm_lpss_apply enable path
pwm_lpss_update will fail causing an error exit and the enable-bit to
never get set. Any following pwm_lpss_apply calls will fail the
pwm_lpss_is_updating check.
Since the docs say that the update bit should be set before the
enable-bit, split pwm_lpss_update into setting the update-bit and
pwm_lpss_wait_for_update, and move the pwm_lpss_wait_for_update call
in the enable path to after setting the enable-bit.
Fixes: 10d56a4 ("pwm: lpss: Avoid reconfiguring while UPDATE bit...")
Cc: Ilkka Koskinen <ilkka.koskinen@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
33 lines
776 B
C
33 lines
776 B
C
/*
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* Intel Low Power Subsystem PWM controller driver
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*
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* Copyright (C) 2014, Intel Corporation
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*
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* Derived from the original pwm-lpss.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef __PWM_LPSS_H
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#define __PWM_LPSS_H
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#include <linux/device.h>
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#include <linux/pwm.h>
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struct pwm_lpss_chip;
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struct pwm_lpss_boardinfo {
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unsigned long clk_rate;
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unsigned int npwm;
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unsigned long base_unit_bits;
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bool bypass;
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};
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struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r,
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const struct pwm_lpss_boardinfo *info);
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int pwm_lpss_remove(struct pwm_lpss_chip *lpwm);
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#endif /* __PWM_LPSS_H */
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