[PATCH v3 5/8] mfd / platform: cros_ec: move device sysfs attributes to its own driver.

From: Enric Balletbo i Serra
Date: Tue Nov 27 2018 - 07:19:14 EST

The entire way how cros debugfs attibutes are created is broken.
cros_ec_sysfs should be its own driver and its attributes should be
associated with the sysfs driver not the mfd driver.

The patch also adds the sysfs documentation.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---

Changes in v3:
- Do not print ec_platform name as is with dev_err is enough.

Changes in v2:
- Create the attributes directly instead of use the attach/detach callbacks.

.../ABI/testing/sysfs-class-chromeos | 32 +++++++++++++++++
drivers/mfd/Kconfig | 1 -
drivers/mfd/cros_ec_dev.c | 7 +---
drivers/platform/chrome/Kconfig | 14 ++++++--
drivers/platform/chrome/Makefile | 3 +-
drivers/platform/chrome/cros_ec_sysfs.c | 36 ++++++++++++++++++-
include/linux/mfd/cros_ec.h | 3 --
7 files changed, 80 insertions(+), 16 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-class-chromeos

diff --git a/Documentation/ABI/testing/sysfs-class-chromeos b/Documentation/ABI/testing/sysfs-class-chromeos
new file mode 100644
index 000000000000..a5399c4ca82d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-chromeos
@@ -0,0 +1,32 @@
+What: /sys/class/chromeos/<cros-ec>/flashinfo
+Date: August 2015
+KernelVersion: 4.2
+Description:
+ Show the EC flash information.
+
+What: /sys/class/chromeos/<cros-ec>/kb_wake_angle
+Date: March 2018
+KernelVersion: 4.17
+Description:
+ Control the keyboard wake lid angle. Values are between
+ 0 and 360. This file will also show the keyboard wake lid
+ angle by querying the hardware.
+
+What: /sys/class/chromeos/<cros-ec>/reboot
+Date: August 2015
+KernelVersion: 4.2
+Description:
+ Tell the EC to reboot in various ways. Options are:
+ "cancel": Cancel a pending reboot.
+ "ro": Jump to RO without rebooting.
+ "rw": Jump to RW without rebooting.
+ "cold": Cold reboot.
+ "disable-jump": Disable jump until next reboot.
+ "hibernate": Hibernate the EC.
+ "at-shutdown": Reboot after an AP shutdown.
+
+What: /sys/class/chromeos/<cros-ec>/version
+Date: August 2015
+KernelVersion: 4.2
+Description:
+ Show the information about the EC software and hardware.
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 8c5dfdce4326..089ffb408918 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -214,7 +214,6 @@ config MFD_CROS_EC
config MFD_CROS_EC_CHARDEV
tristate "Chrome OS Embedded Controller userspace device interface"
depends on MFD_CROS_EC
- select CROS_EC_CTL
---help---
This driver adds support to talk with the ChromeOS EC from userspace.

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 50ba8e0fb4ec..d9b16ce79319 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -34,15 +34,9 @@
#define CROS_MAX_DEV 128
static int ec_major;

-static const struct attribute_group *cros_ec_groups[] = {
- &cros_ec_attr_group,
- NULL,
-};
-
static struct class cros_class = {
.owner = THIS_MODULE,
.name = "chromeos",
- .dev_groups = cros_ec_groups,
};

/* Basic communication */
@@ -391,6 +385,7 @@ static const struct mfd_cell cros_usbpd_charger_cells[] = {
static const struct mfd_cell cros_ec_platform_cells[] = {
{ .name = "cros-ec-debugfs" },
{ .name = "cros-ec-lightbar" },
+ { .name = "cros-ec-sysfs" },
{ .name = "cros-ec-vbc" },
};

diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index 4e4232b47764..b709cc5173a2 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -49,9 +49,6 @@ config CHROMEOS_TBMC
To compile this driver as a module, choose M here: the
module will be called chromeos_tbmc.

-config CROS_EC_CTL
- tristate
-
config CROS_EC_I2C
tristate "ChromeOS Embedded Controller (I2C)"
depends on MFD_CROS_EC && I2C
@@ -142,4 +139,15 @@ config CROS_EC_DEBUGFS
To compile this driver as a module, choose M here: the
module will be called cros_ec_debugfs.

+config CROS_EC_SYSFS
+ tristate "ChromeOS EC control and information through sysfs"
+ depends on MFD_CROS_EC_CHARDEV && SYSFS
+ default y
+ help
+ This option exposes some sysfs attributes to control and get
+ information from ChromeOS EC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called cros_ec_sysfs.
+
endif # CHROMEOS_PLATFORMS
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 12a5c4d18c17..fdbee501931b 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -3,8 +3,6 @@
obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o
obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o
obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o
-cros_ec_ctl-objs := cros_ec_sysfs.o
-obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
@@ -15,3 +13,4 @@ obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
obj-$(CONFIG_CROS_EC_LIGHTBAR) += cros_ec_lightbar.o
obj-$(CONFIG_CROS_EC_VBC) += cros_ec_vbc.o
obj-$(CONFIG_CROS_EC_DEBUGFS) += cros_ec_debugfs.o
+obj-$(CONFIG_CROS_EC_SYSFS) += cros_ec_sysfs.o
diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c
index f34a50121064..0ff5aa30c070 100644
--- a/drivers/platform/chrome/cros_ec_sysfs.c
+++ b/drivers/platform/chrome/cros_ec_sysfs.c
@@ -34,6 +34,8 @@
#include <linux/types.h>
#include <linux/uaccess.h>

+#define DRV_NAME "cros-ec-sysfs"
+
/* Accessor functions */

static ssize_t reboot_show(struct device *dev,
@@ -353,7 +355,39 @@ struct attribute_group cros_ec_attr_group = {
.attrs = __ec_attrs,
.is_visible = cros_ec_ctrl_visible,
};
-EXPORT_SYMBOL(cros_ec_attr_group);
+
+static int cros_ec_sysfs_probe(struct platform_device *pd)
+{
+ struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
+ struct device *dev = &pd->dev;
+ int ret;
+
+ ret = sysfs_create_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
+ if (ret < 0)
+ dev_err(dev, "failed to create attributes. err=%d\n", ret);
+
+ return ret;
+}
+
+static int cros_ec_sysfs_remove(struct platform_device *pd)
+{
+ struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
+
+ sysfs_remove_group(&ec_dev->class_dev.kobj, &cros_ec_attr_group);
+
+ return 0;
+}
+
+static struct platform_driver cros_ec_sysfs_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ },
+ .probe = cros_ec_sysfs_probe,
+ .remove = cros_ec_sysfs_remove,
+};
+
+module_platform_driver(cros_ec_sysfs_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ChromeOS EC control driver");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 3e4401e2ceea..f718ad9c2132 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -323,7 +323,4 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
*/
u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);

-/* sysfs stuff */
-extern struct attribute_group cros_ec_attr_group;
-
#endif /* __LINUX_MFD_CROS_EC_H */
--
2.19.1