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Date: Wed, 17 Oct 2018 12:35:35 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: Re: [PATCH] ACPI: TAD: Add low-level support for real time capability
On Mon, Oct 15, 2018 at 1:59 PM Rafael J. Wysocki <rjw@...ysocki.net> wrote:
>
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
>
> Add low-level support for the (optional) real time capability of the
> ACPI Time and Alarm Device (TAD) to the ACPI TAD driver.
>
> This allows the real time to be acquired or set via sysfs with the
> help of the _GRT and _SRT methods of the TAD, respectively.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> Tested-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
Any objections or concerns here?
If not, I will queue this up.
> ---
> drivers/acpi/acpi_tad.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 201 insertions(+)
>
> Index: linux-pm/drivers/acpi/acpi_tad.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/acpi_tad.c
> +++ linux-pm/drivers/acpi/acpi_tad.c
> @@ -52,6 +52,201 @@ 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(time, S_IRUSR | S_IWUSR, time_show, time_store);
> +
> +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)
> {
> @@ -447,6 +642,12 @@ static int acpi_tad_probe(struct platfor
> 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;
>
>
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