1 // SPDX-License-Identifier: GPL-2.0-only
3 * Intel Low Power Subsystem PWM controller driver
5 * Copyright (C) 2014, Intel Corporation
7 * Derived from the original pwm-lpss.c
10 #include <linux/kernel.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/property.h>
20 static int pwm_lpss_probe_platform(struct platform_device
*pdev
)
22 const struct pwm_lpss_boardinfo
*info
;
23 struct pwm_chip
*chip
;
26 info
= device_get_match_data(&pdev
->dev
);
30 base
= devm_platform_ioremap_resource(pdev
, 0);
34 chip
= devm_pwm_lpss_probe(&pdev
->dev
, base
, info
);
39 * On Cherry Trail devices the GFX0._PS0 AML checks if the controller
40 * is on and if it is not on it turns it on and restores what it
41 * believes is the correct state to the PWM controller.
42 * Because of this we must disallow direct-complete, which keeps the
43 * controller (runtime)suspended on resume, to avoid 2 issues:
44 * 1. The controller getting turned on without the linux-pm code
45 * knowing about this. On devices where the controller is unused
46 * this causes it to stay on during the next suspend causing high
47 * battery drain (because S0i3 is not reached)
48 * 2. The state restoring code unexpectedly messing with the controller
50 * Leaving the controller runtime-suspended (skipping runtime-resume +
51 * normal-suspend) during suspend is fine.
53 if (info
->other_devices_aml_touches_pwm_regs
)
54 dev_pm_set_driver_flags(&pdev
->dev
, DPM_FLAG_NO_DIRECT_COMPLETE
|
55 DPM_FLAG_SMART_SUSPEND
);
57 pm_runtime_set_active(&pdev
->dev
);
58 return devm_pm_runtime_enable(&pdev
->dev
);
61 static const struct acpi_device_id pwm_lpss_acpi_match
[] = {
62 { "80860F09", (unsigned long)&pwm_lpss_byt_info
},
63 { "80862288", (unsigned long)&pwm_lpss_bsw_info
},
64 { "80862289", (unsigned long)&pwm_lpss_bsw_info
},
65 { "80865AC8", (unsigned long)&pwm_lpss_bxt_info
},
68 MODULE_DEVICE_TABLE(acpi
, pwm_lpss_acpi_match
);
70 static struct platform_driver pwm_lpss_driver_platform
= {
73 .acpi_match_table
= pwm_lpss_acpi_match
,
75 .probe
= pwm_lpss_probe_platform
,
77 module_platform_driver(pwm_lpss_driver_platform
);
79 MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
80 MODULE_LICENSE("GPL v2");
81 MODULE_IMPORT_NS("PWM_LPSS");
82 MODULE_ALIAS("platform:pwm-lpss");