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linux/drivers/acpi/acpi_tad.c
Uwe Kleine-König 9a7897a2b0 ACPI: TAD: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-02-27 15:57:33 +01:00

691 lines
16 KiB
C
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// SPDX-License-Identifier: GPL-2.0
/*
* ACPI Time and Alarm (TAD) Device Driver
*
* Copyright (C) 2018 Intel Corporation
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* This driver is based on Section 9.18 of the ACPI 6.2 specification revision.
*
* It only supports the system wakeup capabilities of the TAD.
*
* Provided are sysfs attributes, available under the TAD platform device,
* allowing user space to manage the AC and DC wakeup timers of the TAD:
* set and read their values, set and check their expire timer wake policies,
* check and clear their status and check the capabilities of the TAD reported
* by AML. The DC timer attributes are only present if the TAD supports a
* separate DC alarm timer.
*
* The wakeup events handling and power management of the TAD is expected to
* be taken care of by the ACPI PM domain attached to its platform device.
*/
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/suspend.h>
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Rafael J. Wysocki");
/* ACPI TAD capability flags (ACPI 6.2, Section 9.18.2) */
#define ACPI_TAD_AC_WAKE BIT(0)
#define ACPI_TAD_DC_WAKE BIT(1)
#define ACPI_TAD_RT BIT(2)
#define ACPI_TAD_RT_IN_MS BIT(3)
#define ACPI_TAD_S4_S5__GWS BIT(4)
#define ACPI_TAD_AC_S4_WAKE BIT(5)
#define ACPI_TAD_AC_S5_WAKE BIT(6)
#define ACPI_TAD_DC_S4_WAKE BIT(7)
#define ACPI_TAD_DC_S5_WAKE BIT(8)
/* ACPI TAD alarm timer selection */
#define ACPI_TAD_AC_TIMER (u32)0
#define ACPI_TAD_DC_TIMER (u32)1
/* Special value for disabled timer or expired timer wake policy. */
#define ACPI_TAD_WAKE_DISABLED (~(u32)0)
struct acpi_tad_driver_data {
u32 capabilities;
};
struct acpi_tad_rt {
u16 year; /* 1900 - 9999 */
u8 month; /* 1 - 12 */
u8 day; /* 1 - 31 */
u8 hour; /* 0 - 23 */
u8 minute; /* 0 - 59 */
u8 second; /* 0 - 59 */
u8 valid; /* 0 (failed) or 1 (success) for reads, 0 for writes */
u16 msec; /* 1 - 1000 */
s16 tz; /* -1440 to 1440 or 2047 (unspecified) */
u8 daylight;
u8 padding[3]; /* must be 0 */
} __packed;
static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
{
acpi_handle handle = ACPI_HANDLE(dev);
union acpi_object args[] = {
{ .type = ACPI_TYPE_BUFFER, },
};
struct acpi_object_list arg_list = {
.pointer = args,
.count = ARRAY_SIZE(args),
};
unsigned long long retval;
acpi_status status;
if (rt->year < 1900 || rt->year > 9999 ||
rt->month < 1 || rt->month > 12 ||
rt->hour > 23 || rt->minute > 59 || rt->second > 59 ||
rt->tz < -1440 || (rt->tz > 1440 && rt->tz != 2047) ||
rt->daylight > 3)
return -ERANGE;
args[0].buffer.pointer = (u8 *)rt;
args[0].buffer.length = sizeof(*rt);
pm_runtime_get_sync(dev);
status = acpi_evaluate_integer(handle, "_SRT", &arg_list, &retval);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status) || retval)
return -EIO;
return 0;
}
static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
{
acpi_handle handle = ACPI_HANDLE(dev);
struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER };
union acpi_object *out_obj;
struct acpi_tad_rt *data;
acpi_status status;
int ret = -EIO;
pm_runtime_get_sync(dev);
status = acpi_evaluate_object(handle, "_GRT", NULL, &output);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status))
goto out_free;
out_obj = output.pointer;
if (out_obj->type != ACPI_TYPE_BUFFER)
goto out_free;
if (out_obj->buffer.length != sizeof(*rt))
goto out_free;
data = (struct acpi_tad_rt *)(out_obj->buffer.pointer);
if (!data->valid)
goto out_free;
memcpy(rt, data, sizeof(*rt));
ret = 0;
out_free:
ACPI_FREE(output.pointer);
return ret;
}
static char *acpi_tad_rt_next_field(char *s, int *val)
{
char *p;
p = strchr(s, ':');
if (!p)
return NULL;
*p = '\0';
if (kstrtoint(s, 10, val))
return NULL;
return p + 1;
}
static ssize_t time_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct acpi_tad_rt rt;
char *str, *s;
int val, ret = -ENODATA;
str = kmemdup_nul(buf, count, GFP_KERNEL);
if (!str)
return -ENOMEM;
s = acpi_tad_rt_next_field(str, &val);
if (!s)
goto out_free;
rt.year = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.month = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.day = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.hour = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.minute = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.second = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.tz = val;
if (kstrtoint(s, 10, &val))
goto out_free;
rt.daylight = val;
rt.valid = 0;
rt.msec = 0;
memset(rt.padding, 0, 3);
ret = acpi_tad_set_real_time(dev, &rt);
out_free:
kfree(str);
return ret ? ret : count;
}
static ssize_t time_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct acpi_tad_rt rt;
int ret;
ret = acpi_tad_get_real_time(dev, &rt);
if (ret)
return ret;
return sprintf(buf, "%u:%u:%u:%u:%u:%u:%d:%u\n",
rt.year, rt.month, rt.day, rt.hour, rt.minute, rt.second,
rt.tz, rt.daylight);
}
static DEVICE_ATTR_RW(time);
static struct attribute *acpi_tad_time_attrs[] = {
&dev_attr_time.attr,
NULL,
};
static const struct attribute_group acpi_tad_time_attr_group = {
.attrs = acpi_tad_time_attrs,
};
static int acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
u32 value)
{
acpi_handle handle = ACPI_HANDLE(dev);
union acpi_object args[] = {
{ .type = ACPI_TYPE_INTEGER, },
{ .type = ACPI_TYPE_INTEGER, },
};
struct acpi_object_list arg_list = {
.pointer = args,
.count = ARRAY_SIZE(args),
};
unsigned long long retval;
acpi_status status;
args[0].integer.value = timer_id;
args[1].integer.value = value;
pm_runtime_get_sync(dev);
status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status) || retval)
return -EIO;
return 0;
}
static int acpi_tad_wake_write(struct device *dev, const char *buf, char *method,
u32 timer_id, const char *specval)
{
u32 value;
if (sysfs_streq(buf, specval)) {
value = ACPI_TAD_WAKE_DISABLED;
} else {
int ret = kstrtou32(buf, 0, &value);
if (ret)
return ret;
if (value == ACPI_TAD_WAKE_DISABLED)
return -EINVAL;
}
return acpi_tad_wake_set(dev, method, timer_id, value);
}
static ssize_t acpi_tad_wake_read(struct device *dev, char *buf, char *method,
u32 timer_id, const char *specval)
{
acpi_handle handle = ACPI_HANDLE(dev);
union acpi_object args[] = {
{ .type = ACPI_TYPE_INTEGER, },
};
struct acpi_object_list arg_list = {
.pointer = args,
.count = ARRAY_SIZE(args),
};
unsigned long long retval;
acpi_status status;
args[0].integer.value = timer_id;
pm_runtime_get_sync(dev);
status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status))
return -EIO;
if ((u32)retval == ACPI_TAD_WAKE_DISABLED)
return sprintf(buf, "%s\n", specval);
return sprintf(buf, "%u\n", (u32)retval);
}
static const char *alarm_specval = "disabled";
static int acpi_tad_alarm_write(struct device *dev, const char *buf,
u32 timer_id)
{
return acpi_tad_wake_write(dev, buf, "_STV", timer_id, alarm_specval);
}
static ssize_t acpi_tad_alarm_read(struct device *dev, char *buf, u32 timer_id)
{
return acpi_tad_wake_read(dev, buf, "_TIV", timer_id, alarm_specval);
}
static const char *policy_specval = "never";
static int acpi_tad_policy_write(struct device *dev, const char *buf,
u32 timer_id)
{
return acpi_tad_wake_write(dev, buf, "_STP", timer_id, policy_specval);
}
static ssize_t acpi_tad_policy_read(struct device *dev, char *buf, u32 timer_id)
{
return acpi_tad_wake_read(dev, buf, "_TIP", timer_id, policy_specval);
}
static int acpi_tad_clear_status(struct device *dev, u32 timer_id)
{
acpi_handle handle = ACPI_HANDLE(dev);
union acpi_object args[] = {
{ .type = ACPI_TYPE_INTEGER, },
};
struct acpi_object_list arg_list = {
.pointer = args,
.count = ARRAY_SIZE(args),
};
unsigned long long retval;
acpi_status status;
args[0].integer.value = timer_id;
pm_runtime_get_sync(dev);
status = acpi_evaluate_integer(handle, "_CWS", &arg_list, &retval);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status) || retval)
return -EIO;
return 0;
}
static int acpi_tad_status_write(struct device *dev, const char *buf, u32 timer_id)
{
int ret, value;
ret = kstrtoint(buf, 0, &value);
if (ret)
return ret;
if (value)
return -EINVAL;
return acpi_tad_clear_status(dev, timer_id);
}
static ssize_t acpi_tad_status_read(struct device *dev, char *buf, u32 timer_id)
{
acpi_handle handle = ACPI_HANDLE(dev);
union acpi_object args[] = {
{ .type = ACPI_TYPE_INTEGER, },
};
struct acpi_object_list arg_list = {
.pointer = args,
.count = ARRAY_SIZE(args),
};
unsigned long long retval;
acpi_status status;
args[0].integer.value = timer_id;
pm_runtime_get_sync(dev);
status = acpi_evaluate_integer(handle, "_GWS", &arg_list, &retval);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status))
return -EIO;
return sprintf(buf, "0x%02X\n", (u32)retval);
}
static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);
return sprintf(buf, "0x%02X\n", dd->capabilities);
}
static DEVICE_ATTR_RO(caps);
static ssize_t ac_alarm_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_AC_TIMER);
return ret ? ret : count;
}
static ssize_t ac_alarm_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return acpi_tad_alarm_read(dev, buf, ACPI_TAD_AC_TIMER);
}
static DEVICE_ATTR_RW(ac_alarm);
static ssize_t ac_policy_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_AC_TIMER);
return ret ? ret : count;
}
static ssize_t ac_policy_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return acpi_tad_policy_read(dev, buf, ACPI_TAD_AC_TIMER);
}
static DEVICE_ATTR_RW(ac_policy);
static ssize_t ac_status_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_AC_TIMER);
return ret ? ret : count;
}
static ssize_t ac_status_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return acpi_tad_status_read(dev, buf, ACPI_TAD_AC_TIMER);
}
static DEVICE_ATTR_RW(ac_status);
static struct attribute *acpi_tad_attrs[] = {
&dev_attr_caps.attr,
&dev_attr_ac_alarm.attr,
&dev_attr_ac_policy.attr,
&dev_attr_ac_status.attr,
NULL,
};
static const struct attribute_group acpi_tad_attr_group = {
.attrs = acpi_tad_attrs,
};
static ssize_t dc_alarm_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_DC_TIMER);
return ret ? ret : count;
}
static ssize_t dc_alarm_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return acpi_tad_alarm_read(dev, buf, ACPI_TAD_DC_TIMER);
}
static DEVICE_ATTR_RW(dc_alarm);
static ssize_t dc_policy_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_DC_TIMER);
return ret ? ret : count;
}
static ssize_t dc_policy_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return acpi_tad_policy_read(dev, buf, ACPI_TAD_DC_TIMER);
}
static DEVICE_ATTR_RW(dc_policy);
static ssize_t dc_status_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_DC_TIMER);
return ret ? ret : count;
}
static ssize_t dc_status_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return acpi_tad_status_read(dev, buf, ACPI_TAD_DC_TIMER);
}
static DEVICE_ATTR_RW(dc_status);
static struct attribute *acpi_tad_dc_attrs[] = {
&dev_attr_dc_alarm.attr,
&dev_attr_dc_policy.attr,
&dev_attr_dc_status.attr,
NULL,
};
static const struct attribute_group acpi_tad_dc_attr_group = {
.attrs = acpi_tad_dc_attrs,
};
static int acpi_tad_disable_timer(struct device *dev, u32 timer_id)
{
return acpi_tad_wake_set(dev, "_STV", timer_id, ACPI_TAD_WAKE_DISABLED);
}
static void acpi_tad_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
acpi_handle handle = ACPI_HANDLE(dev);
struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);
device_init_wakeup(dev, false);
pm_runtime_get_sync(dev);
if (dd->capabilities & ACPI_TAD_DC_WAKE)
sysfs_remove_group(&dev->kobj, &acpi_tad_dc_attr_group);
sysfs_remove_group(&dev->kobj, &acpi_tad_attr_group);
acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER);
acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER);
if (dd->capabilities & ACPI_TAD_DC_WAKE) {
acpi_tad_disable_timer(dev, ACPI_TAD_DC_TIMER);
acpi_tad_clear_status(dev, ACPI_TAD_DC_TIMER);
}
pm_runtime_put_sync(dev);
pm_runtime_disable(dev);
acpi_remove_cmos_rtc_space_handler(handle);
}
static int acpi_tad_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
acpi_handle handle = ACPI_HANDLE(dev);
struct acpi_tad_driver_data *dd;
acpi_status status;
unsigned long long caps;
int ret;
ret = acpi_install_cmos_rtc_space_handler(handle);
if (ret < 0) {
dev_info(dev, "Unable to install space handler\n");
return -ENODEV;
}
/*
* Initialization failure messages are mostly about firmware issues, so
* print them at the "info" level.
*/
status = acpi_evaluate_integer(handle, "_GCP", NULL, &caps);
if (ACPI_FAILURE(status)) {
dev_info(dev, "Unable to get capabilities\n");
ret = -ENODEV;
goto remove_handler;
}
if (!(caps & ACPI_TAD_AC_WAKE)) {
dev_info(dev, "Unsupported capabilities\n");
ret = -ENODEV;
goto remove_handler;
}
if (!acpi_has_method(handle, "_PRW")) {
dev_info(dev, "Missing _PRW\n");
ret = -ENODEV;
goto remove_handler;
}
dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
if (!dd) {
ret = -ENOMEM;
goto remove_handler;
}
dd->capabilities = caps;
dev_set_drvdata(dev, dd);
/*
* Assume that the ACPI PM domain has been attached to the device and
* simply enable system wakeup and runtime PM and put the device into
* runtime suspend. Everything else should be taken care of by the ACPI
* PM domain callbacks.
*/
device_init_wakeup(dev, true);
dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
DPM_FLAG_MAY_SKIP_RESUME);
/*
* The platform bus type layer tells the ACPI PM domain powers up the
* device, so set the runtime PM status of it to "active".
*/
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
pm_runtime_suspend(dev);
ret = sysfs_create_group(&dev->kobj, &acpi_tad_attr_group);
if (ret)
goto fail;
if (caps & ACPI_TAD_DC_WAKE) {
ret = sysfs_create_group(&dev->kobj, &acpi_tad_dc_attr_group);
if (ret)
goto fail;
}
if (caps & ACPI_TAD_RT) {
ret = sysfs_create_group(&dev->kobj, &acpi_tad_time_attr_group);
if (ret)
goto fail;
}
return 0;
fail:
acpi_tad_remove(pdev);
/* Don't fallthrough because cmos rtc space handler is removed in acpi_tad_remove() */
return ret;
remove_handler:
acpi_remove_cmos_rtc_space_handler(handle);
return ret;
}
static const struct acpi_device_id acpi_tad_ids[] = {
{"ACPI000E", 0},
{}
};
static struct platform_driver acpi_tad_driver = {
.driver = {
.name = "acpi-tad",
.acpi_match_table = acpi_tad_ids,
},
.probe = acpi_tad_probe,
.remove_new = acpi_tad_remove,
};
MODULE_DEVICE_TABLE(acpi, acpi_tad_ids);
module_platform_driver(acpi_tad_driver);
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