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>
97 lines
2.3 KiB
C
97 lines
2.3 KiB
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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#include <linux/acpi.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include "pwm-lpss.h"
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/* BayTrail */
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static const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
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.clk_rate = 25000000,
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.npwm = 1,
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.base_unit_bits = 16,
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};
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/* Braswell */
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static const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
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.clk_rate = 19200000,
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.npwm = 1,
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.base_unit_bits = 16,
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};
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/* Broxton */
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static const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
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.clk_rate = 19200000,
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.npwm = 4,
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.base_unit_bits = 22,
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.bypass = true,
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};
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static int pwm_lpss_probe_platform(struct platform_device *pdev)
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{
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const struct pwm_lpss_boardinfo *info;
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const struct acpi_device_id *id;
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struct pwm_lpss_chip *lpwm;
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struct resource *r;
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id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
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if (!id)
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return -ENODEV;
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info = (const struct pwm_lpss_boardinfo *)id->driver_data;
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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lpwm = pwm_lpss_probe(&pdev->dev, r, info);
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if (IS_ERR(lpwm))
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return PTR_ERR(lpwm);
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platform_set_drvdata(pdev, lpwm);
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pm_runtime_set_active(&pdev->dev);
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pm_runtime_enable(&pdev->dev);
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return 0;
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}
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static int pwm_lpss_remove_platform(struct platform_device *pdev)
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{
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struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);
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pm_runtime_disable(&pdev->dev);
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return pwm_lpss_remove(lpwm);
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}
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static const struct acpi_device_id pwm_lpss_acpi_match[] = {
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{ "80860F09", (unsigned long)&pwm_lpss_byt_info },
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{ "80862288", (unsigned long)&pwm_lpss_bsw_info },
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{ "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
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{ },
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};
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MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
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static struct platform_driver pwm_lpss_driver_platform = {
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.driver = {
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.name = "pwm-lpss",
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.acpi_match_table = pwm_lpss_acpi_match,
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},
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.probe = pwm_lpss_probe_platform,
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.remove = pwm_lpss_remove_platform,
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};
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module_platform_driver(pwm_lpss_driver_platform);
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MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:pwm-lpss");
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