Messages in this thread | | | From | Enric Balletbo Serra <> | Date | Tue, 15 Jan 2019 20:32:19 +0100 | Subject | Re: [PATCH v2 3/9] platform/chrome: Add sysfs attributes |
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Hi Nick,
Some few comments more ...
Missatge de Nick Crews <ncrews@google.com> del dia dl., 14 de gen. 2019 a les 23:07: > > From: Duncan Laurie <dlaurie@google.com> > > Add some sample sysfs attributes for the Wilco EC that show how > the mailbox interface works. "Legacy" attributes are those that > existed in the EC before it was adapted to ChromeOS. > > > cat /sys/bus/platform/devices/GOOG000C\:00/version > Label : 99.99.99 > SVN Revision : 738ed.99 > Model Number : 08;8 > Build Date : 08/30/18 > > Signed-off-by: Duncan Laurie <dlaurie@google.com> > Signed-off-by: Nick Crews <ncrews@google.com> > --- > > Changes in v2: > - Remove license boiler plate > - Remove "wilco_ec_sysfs -" docstring prefix > - Fix accidental Makefile deletion > - Add documentation for sysfs entries > - Change "enable ? 0 : 1" to "!enable" > - No longer override error code from sysfs_init() > - Put attributes in the legacy file to begin with, don't move later > - Remove duplicate error messages in sysfs_init() and its caller > > .../ABI/testing/sysfs-platform-wilcoec | 26 ++++++ > drivers/platform/chrome/wilco_ec/Makefile | 2 +- > drivers/platform/chrome/wilco_ec/core.c | 15 +++ > drivers/platform/chrome/wilco_ec/legacy.c | 91 +++++++++++++++++++ > drivers/platform/chrome/wilco_ec/legacy.h | 47 ++++++++++ > drivers/platform/chrome/wilco_ec/sysfs.c | 66 ++++++++++++++ > include/linux/platform_data/wilco-ec.h | 14 +++ > 7 files changed, 260 insertions(+), 1 deletion(-) > create mode 100644 Documentation/ABI/testing/sysfs-platform-wilcoec
I'd like to rename this to sysfs-platform-wilco-ec (like cros-ec)
> create mode 100644 drivers/platform/chrome/wilco_ec/legacy.c > create mode 100644 drivers/platform/chrome/wilco_ec/legacy.h > create mode 100644 drivers/platform/chrome/wilco_ec/sysfs.c > > diff --git a/Documentation/ABI/testing/sysfs-platform-wilcoec b/Documentation/ABI/testing/sysfs-platform-wilcoec > new file mode 100644 > index 000000000000..09552338c160 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-platform-wilcoec > @@ -0,0 +1,26 @@ > +What: /sys/bus/platform/devices/GOOG000C\:00/version > +Date: January 2019 > +KernelVersion: 4.19
That will be probably 5.1
> +Description: > + Display Wilco Embedded Controller version info > + > + Output will be similar to the example below: > + Label : 95.00.06 > + SVN Revision : 5960a.06 > + Model Number : 08;8 > + Build Date : 11/29/18 > + > + Although this contains multiple pieces of data in a single sysfs > + attribute (inconsistent with normal sysfs conventions), > + this format was chosen to be consistent with the version > + attribute in /sys/class/chomeos/<device>/version > +
I don't buy the reason to be inconsistent. I don't think you need to be consistent with something that is wrong and not following the conventions. Past errors should be fixed :)
I'd like to see here single values in single attributes, this will also be easier to parse from userspace point of view.
> +What: /sys/bus/platform/devices/GOOG000C\:00/stealth_mode > +Date: January 2019 > +KernelVersion: 4.19 > +Description: > + Turn stealth_mode on or off on EC. Stealth mode means that the > + various LEDs, the LCD backlight, and onboard speakers are turned > + off and remain off even if activated from the off state. > + External monitors connected to the system are not affected. > + In addition Wireless devices are turned off.
Would be good to specify the valid values to write.
> diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile > index 03b32301dc61..7965a39e2e7a 100644 > --- a/drivers/platform/chrome/wilco_ec/Makefile > +++ b/drivers/platform/chrome/wilco_ec/Makefile > @@ -1,4 +1,4 @@ > # SPDX-License-Identifier: GPL-2.0 > > -wilco_ec-objs := core.o mailbox.o > +wilco_ec-objs := core.o mailbox.o sysfs.o legacy.o > obj-$(CONFIG_WILCO_EC) += wilco_ec.o > diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c > index 2d1d8d3f9a94..3193e8b2ec91 100644 > --- a/drivers/platform/chrome/wilco_ec/core.c > +++ b/drivers/platform/chrome/wilco_ec/core.c > @@ -64,11 +64,26 @@ static int wilco_ec_probe(struct platform_device *pdev) > cros_ec_lpc_mec_init(ec->io_packet->start, > ec->io_packet->start + EC_MAILBOX_DATA_SIZE); > > + /* Create sysfs attributes for userspace interaction */ > + ret = wilco_ec_sysfs_init(ec); > + if (ret < 0) { > + dev_err(dev, "Failed to create sysfs attributes\n"); > + goto destroy_lpc_mec; > + } > return 0; > + > +destroy_lpc_mec: > + cros_ec_lpc_mec_destroy(); > + return ret; > } > > static int wilco_ec_remove(struct platform_device *pdev) > { > + struct wilco_ec_device *ec = platform_get_drvdata(pdev); > + > + /* Remove sysfs attributes */ > + wilco_ec_sysfs_remove(ec); > + > /* Teardown cros_ec interface */ > cros_ec_lpc_mec_destroy(); > > diff --git a/drivers/platform/chrome/wilco_ec/legacy.c b/drivers/platform/chrome/wilco_ec/legacy.c > new file mode 100644 > index 000000000000..1fdf94d22f57 > --- /dev/null > +++ b/drivers/platform/chrome/wilco_ec/legacy.c > @@ -0,0 +1,91 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Legacy (non-Chrome-specific) sysfs attributes for Wilco EC > + * > + * Copyright 2018 Google LLC > + */ > + > +#include <linux/ctype.h> > +#include <linux/device.h> > +#include <linux/platform_data/wilco-ec.h> > + > +#include "legacy.h" > + > +struct ec_info { > + u8 index; > + const char *label; > +}; > + > +static ssize_t wilco_ec_show_info(struct wilco_ec_device *ec, char *buf, > + ssize_t count, struct ec_info *info) > +{ > + char result[EC_INFO_SIZE]; > + struct wilco_ec_message msg = { > + .type = WILCO_EC_MSG_LEGACY, > + .command = EC_COMMAND_EC_INFO, > + .request_data = &info->index, > + .request_size = sizeof(info->index), > + .response_data = result, > + .response_size = EC_INFO_SIZE, > + }; > + int ret; > + > + ret = wilco_ec_mailbox(ec, &msg); > + if (ret != EC_INFO_SIZE) > + return scnprintf(buf + count, PAGE_SIZE - count, > + "%-12s : ERROR %d\n", info->label, ret); > + > + return scnprintf(buf + count, PAGE_SIZE - count, > + "%-12s : %s\n", info->label, result); > +} > + > +ssize_t wilco_ec_version_show(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + struct wilco_ec_device *ec = dev_get_drvdata(dev); > + struct ec_info wilco_ec_info[] = { > + { 0, "Label" }, > + { 1, "SVN Revision" }, > + { 2, "Model Number" }, > + { 3, "Build Date" }, > + { 0xff, NULL }, > + }; > + struct ec_info *info = wilco_ec_info; > + ssize_t c = 0; > + > + for (info = wilco_ec_info; info->label; info++) > + c += wilco_ec_show_info(ec, buf, c, info); > + > + return c; > +} > + > +ssize_t wilco_ec_stealth_mode_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct wilco_ec_device *ec = dev_get_drvdata(dev); > + u8 param; > + struct wilco_ec_message msg = { > + .type = WILCO_EC_MSG_LEGACY, > + .command = EC_COMMAND_STEALTH_MODE, > + .request_data = ¶m, > + .request_size = sizeof(param), > + }; > + int ret; > + bool enable; > + > + ret = kstrtobool(buf, &enable); > + if (ret) { > + dev_err(dev, "Unable to parse '%s' to bool", buf); > + return ret; > + } > + > + /* Invert input parameter, EC expects 0=on and 1=off */ > + param = !enable; > + > + ret = wilco_ec_mailbox(ec, &msg); > + if (ret < 0) > + return ret; > + > + return count; > +} > diff --git a/drivers/platform/chrome/wilco_ec/legacy.h b/drivers/platform/chrome/wilco_ec/legacy.h > new file mode 100644 > index 000000000000..5c857cb57fa9 > --- /dev/null > +++ b/drivers/platform/chrome/wilco_ec/legacy.h > @@ -0,0 +1,47 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Legacy (non-Chrome-specific) sysfs attributes for Wilco EC > + * > + * Copyright 2018 Google LLC > + */ > + > +#ifndef WILCO_EC_LEGACY_H > +#define WILCO_EC_LEGACY_H > + > +#include <linux/device.h> > + > +#define EC_COMMAND_EC_INFO 0x38 > +#define EC_INFO_SIZE 9 > +#define EC_COMMAND_STEALTH_MODE 0xfc > + > +/** > + * wilco_ec_version_show() - Display Wilco Embedded Controller version info > + * > + * Output will be similar to the example below: > + * Label : 95.00.06 > + * SVN Revision : 5960a.06 > + * Model Number : 08;8 > + * Build Date : 11/29/18 > + * > + * Although this contains multiple pieces of data in a single sysfs attribute > + * (inconsistent with normal sysfs conventions), this format was chosen to be > + * consistent with the version attribute in ../cros_ec_sysfs.c > + */ > +ssize_t wilco_ec_version_show(struct device *dev, struct device_attribute *attr, > + char *buf); > + > +/** > + * wilco_ec_stealth_mode_store() - Turn stealth_mode on or off on EC > + * @dev: Device representing the EC > + * @attr: The attribute in question > + * @buf: Input buffer, should be parseable by kstrtobool(). Anything parsed to > + * True means enable stealth mode (turn off screen, etc) > + * @count: Number of bytes in input buffer > + * > + * Return: Number of bytes consumed from input, negative error code on failure > + */ > +ssize_t wilco_ec_stealth_mode_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count); > + > +#endif /* WILCO_EC_LEGACY_H */ > diff --git a/drivers/platform/chrome/wilco_ec/sysfs.c b/drivers/platform/chrome/wilco_ec/sysfs.c > new file mode 100644 > index 000000000000..e78a3ec3506b > --- /dev/null > +++ b/drivers/platform/chrome/wilco_ec/sysfs.c > @@ -0,0 +1,66 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Sysfs attributes for Wilco Embedded Controller > + * > + * Copyright 2018 Google LLC > + * > + * The sysfs attributes appear under /sys/bus/platform/devices/GOOG000C\:00/ > + * To actually learn what each attribute does, read the corresponding _show() or > + * _store() function source. > + */ > + > +#include <linux/ctype.h> > +#include <linux/platform_data/wilco-ec.h> > +#include <linux/platform_device.h> > +#include <linux/sysfs.h> > + > +#include "legacy.h" > + > +#define WILCO_EC_ATTR_RO(_name) \ > +__ATTR(_name, 0444, wilco_ec_##_name##_show, NULL) > + > +#define WILCO_EC_ATTR_WO(_name) \ > +__ATTR(_name, 0200, NULL, wilco_ec_##_name##_store) > + > +#define WILCO_EC_ATTR_RW(_name) \ > +__ATTR(_name, 0644, wilco_ec_##_name##_show, wilco_ec_##_name##_store) > +
Why not use the already defined DEVICE_ATTR_* family instead?
> +/* Make top-level attributes, which will live inside GOOG000C:00/ */ > +static struct device_attribute version_attr = WILCO_EC_ATTR_RO(version); > +static struct device_attribute stealth_attr = WILCO_EC_ATTR_WO(stealth_mode); > +static struct attribute *wilco_ec_toplevel_attrs[] = { > + &version_attr.attr, > + &stealth_attr.attr, > + NULL > +}; > +ATTRIBUTE_GROUPS(wilco_ec_toplevel); > + > +/** > + * wilco_ec_sysfs_init() - Initialize the sysfs directories and attributes > + * @dev: The device representing the EC > + * > + * Creates the sysfs directory structure and populates it with all attributes. > + * If there is a problem it will clean up the entire filesystem. > + * > + * Return 0 on success, -ENOMEM on failure creating directories or attibutes. > + */ > +int wilco_ec_sysfs_init(struct wilco_ec_device *ec) > +{ > + struct device *dev = ec->dev; > + int ret; > + > + /* add the top-level attributes */ > + ret = sysfs_create_groups(&dev->kobj, wilco_ec_toplevel_groups); > + if (ret) > + return -ENOMEM;
Do not overwrite the error, return ret;
> + > + return 0; > +} > + > +void wilco_ec_sysfs_remove(struct wilco_ec_device *ec) > +{ > + struct device *dev = ec->dev; > + > + /* go upwards through the directory structure */ > + sysfs_remove_groups(&dev->kobj, wilco_ec_toplevel_groups); > +} > diff --git a/include/linux/platform_data/wilco-ec.h b/include/linux/platform_data/wilco-ec.h > index 5477b8802f81..7c6ab6de7239 100644 > --- a/include/linux/platform_data/wilco-ec.h > +++ b/include/linux/platform_data/wilco-ec.h > @@ -135,4 +135,18 @@ struct wilco_ec_response { > */ > int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg); > > +/** > + * wilco_ec_sysfs_init() - Create sysfs attributes. > + * @ec: EC device. > + * > + * Return: 0 for success or negative error code on failure. > + */ > +int wilco_ec_sysfs_init(struct wilco_ec_device *ec); > + > +/** > + * wilco_ec_sysfs_remove() - Remove sysfs attributes. > + * @ec: EC device. > + */ > +void wilco_ec_sysfs_remove(struct wilco_ec_device *ec); > + > #endif /* WILCO_EC_H */ > -- > 2.20.1.97.g81188d93c3-goog >
Thanks, Enric
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