Re: [PATCH v3 1/2] platform/chrome: wilco_ec: Add Boot on AC support
From: Enric Balletbo Serra
Date: Thu May 09 2019 - 17:32:46 EST
Hi Nick,
Thanks for the patch, some few comments below...
Missatge de Nick Crews <ncrews@xxxxxxxxxxxx> del dia dc., 17 dâabr.
2019 a les 3:22:
>
> Boot on AC is a policy which makes the device boot from S5 when AC
> power is connected. This is useful for users who want to run their
> device headless or with a dock.
>
> v3 changes:
> - Add docstring to wilco_ec_add_sysfs()
> - Tweak a comment
> - Use val > 1 instead of val != 0 && val != 1
> v2 changes:
> - Move documentation to Documentation/ABI/testing/sysfs-platform-wilco-ec
>
> Signed-off-by: Nick Crews <ncrews@xxxxxxxxxxxx>
> ---
> .../ABI/testing/sysfs-platform-wilco-ec | 11 +++
> drivers/platform/chrome/wilco_ec/Makefile | 2 +-
> drivers/platform/chrome/wilco_ec/core.c | 9 +++
> drivers/platform/chrome/wilco_ec/sysfs.c | 77 +++++++++++++++++++
> include/linux/platform_data/wilco-ec.h | 12 +++
> 5 files changed, 110 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/ABI/testing/sysfs-platform-wilco-ec
> create mode 100644 drivers/platform/chrome/wilco_ec/sysfs.c
>
> diff --git a/Documentation/ABI/testing/sysfs-platform-wilco-ec b/Documentation/ABI/testing/sysfs-platform-wilco-ec
> new file mode 100644
> index 000000000000..e074c203cd32
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-platform-wilco-ec
> @@ -0,0 +1,11 @@
> +What: /sys/bus/platform/devices/GOOG000C\:00/boot_on_ac
> +Date: April 2019
> +KernelVersion: 5.2
> +Description:
> + Boot on AC is a policy which makes the device boot from S5
> + when AC power is connected. This is useful for users who
> + want to run their device headless or with a dock.
> +
> + Input should be parseable by kstrtou8() to 0 or 1.
> + Output will be either "0\n" or "1\n".
> +
> diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile
> index 063e7fb4ea17..1281dd7737c4 100644
> --- a/drivers/platform/chrome/wilco_ec/Makefile
> +++ b/drivers/platform/chrome/wilco_ec/Makefile
> @@ -1,6 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -wilco_ec-objs := core.o mailbox.o
> +wilco_ec-objs := core.o mailbox.o sysfs.o
> obj-$(CONFIG_WILCO_EC) += wilco_ec.o
> wilco_ec_debugfs-objs := debugfs.o
> obj-$(CONFIG_WILCO_EC_DEBUGFS) += wilco_ec_debugfs.o
> diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c
> index 05e1e2be1c91..abd15d04e57b 100644
> --- a/drivers/platform/chrome/wilco_ec/core.c
> +++ b/drivers/platform/chrome/wilco_ec/core.c
> @@ -89,8 +89,16 @@ static int wilco_ec_probe(struct platform_device *pdev)
> goto unregister_debugfs;
> }
>
> + ret = wilco_ec_add_sysfs(ec);
> + if (ret < 0) {
> + dev_err(dev, "Failed to create sysfs entries: %d", ret);
> + goto unregister_rtc;
> + }
> +
> return 0;
>
> +unregister_rtc:
> + platform_device_unregister(ec->rtc_pdev);
> unregister_debugfs:
> if (ec->debugfs_pdev)
> platform_device_unregister(ec->debugfs_pdev);
> @@ -102,6 +110,7 @@ static int wilco_ec_remove(struct platform_device *pdev)
> {
> struct wilco_ec_device *ec = platform_get_drvdata(pdev);
>
> + wilco_ec_remove_sysfs(ec);
> platform_device_unregister(ec->rtc_pdev);
> if (ec->debugfs_pdev)
> platform_device_unregister(ec->debugfs_pdev);
> diff --git a/drivers/platform/chrome/wilco_ec/sysfs.c b/drivers/platform/chrome/wilco_ec/sysfs.c
> new file mode 100644
> index 000000000000..959b5da2eb16
> --- /dev/null
> +++ b/drivers/platform/chrome/wilco_ec/sysfs.c
> @@ -0,0 +1,77 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 Google LLC
> + *
> + * Sysfs properties to view and modify EC-controlled features on Wilco devices.
> + * The entries will appear under /sys/bus/platform/devices/GOOG000C:00/
> + *
> + * See Documentation/ABI/testing/sysfs-platform-wilco-ec for more information.
> + */
> +
> +#include <linux/platform_data/wilco-ec.h>
> +#include <linux/sysfs.h>
> +
> +#define CMD_KB_CMOS 0x7C
> +#define SUB_CMD_KB_CMOS_AUTO_ON 0x03
> +
> +struct boot_on_ac_request {
> + u8 cmd; /* Always CMD_KB_CMOS */
> + u8 reserved1;
> + u8 sub_cmd; /* Always SUB_CMD_KB_CMOS_AUTO_ON */
> + u8 reserved3to5[3];
> + u8 val; /* Either 0 or 1 */
> + u8 reserved7;
> +} __packed;
> +
> +static ssize_t boot_on_ac_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct wilco_ec_device *ec = dev_get_drvdata(dev);
> + struct boot_on_ac_request rq;
> + struct wilco_ec_message msg;
> + int ret;
> + u8 val;
> +
> + ret = kstrtou8(buf, 10, &val);
> + if (ret < 0)
> + return ret;
> + if (val > 1)
> + return -EINVAL;
> +
> + memset(&rq, 0, sizeof(rq));
> + rq.cmd = CMD_KB_CMOS;
> + rq.sub_cmd = SUB_CMD_KB_CMOS_AUTO_ON;
> + rq.val = val;
> +
> + memset(&msg, 0, sizeof(msg));
> + msg.type = WILCO_EC_MSG_LEGACY;
> + msg.request_data = &rq;
> + msg.request_size = sizeof(rq);
> + ret = wilco_ec_mailbox(ec, &msg);
> + if (ret < 0)
> + return ret;
> +
> + return count;
> +}
> +
> +static DEVICE_ATTR_WO(boot_on_ac);
Is not possible to read the flag? From the API description seems that it is.
> +
> +static struct attribute *wilco_dev_attrs[] = {
> + &dev_attr_boot_on_ac.attr,
> + NULL,
> +};
> +
> +static struct attribute_group wilco_dev_attr_group = {
> + .attrs = wilco_dev_attrs,
> +};
> +
> +int wilco_ec_add_sysfs(struct wilco_ec_device *ec)
> +{
> + return sysfs_create_group(&ec->dev->kobj, &wilco_dev_attr_group);
> +}
> +
> +void wilco_ec_remove_sysfs(struct wilco_ec_device *ec)
> +{
> + sysfs_create_group(&ec->dev->kobj, &wilco_dev_attr_group);
As Guenter pointed: sysfs_remove_group()
> +}
> diff --git a/include/linux/platform_data/wilco-ec.h b/include/linux/platform_data/wilco-ec.h
> index 1ff224793c99..7809b098ce27 100644
> --- a/include/linux/platform_data/wilco-ec.h
> +++ b/include/linux/platform_data/wilco-ec.h
> @@ -123,4 +123,16 @@ struct wilco_ec_message {
> */
> int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg);
>
> +/**
> + * wilco_ec_add_sysfs() - Create sysfs entries
> + * @ec: Wilco EC device
> + *
> + * wilco_ec_remove_sysfs() needs to be called afterwards
> + * to perform the necessary cleanup.
> + *
> + * Return: 0 on success or negative error code on failure.
> + */
> +int wilco_ec_add_sysfs(struct wilco_ec_device *ec);
> +void wilco_ec_remove_sysfs(struct wilco_ec_device *ec);
> +
> #endif /* WILCO_EC_H */
> --
> 2.20.1
>