From ecf8a6cd949ef236ce435ae488ceb6b3354e677e Mon Sep 17 00:00:00 2001 From: Enric Balletbo i Serra Date: Wed, 12 Dec 2018 18:33:57 +0100 Subject: [PATCH] mfd / platform: cros_ec: Move lightbar attributes to its own driver The entire way how cros sysfs attibutes are created is broken. cros_ec_lightbar should be its own driver and its attributes should be associated with a lightbar driver not the mfd driver. In order to retain the path, the lightbar attributes are attached to the cros_class. The patch also adds the sysfs documentation. Signed-off-by: Enric Balletbo i Serra Reviewed-by: Guenter Roeck Signed-off-by: Lee Jones --- ...sfs-class-chromeos-driver-cros-ec-lightbar | 74 +++++++++++++++ drivers/mfd/cros_ec_dev.c | 24 ++--- drivers/mfd/cros_ec_dev.h | 6 -- drivers/platform/chrome/Kconfig | 11 +++ drivers/platform/chrome/Makefile | 3 +- drivers/platform/chrome/cros_ec_lightbar.c | 95 ++++++++++++++----- include/linux/mfd/cros_ec.h | 1 - 7 files changed, 173 insertions(+), 41 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar diff --git a/Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar b/Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar new file mode 100644 index 000000000000..57a037791403 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar @@ -0,0 +1,74 @@ +What: /sys/class/chromeos//lightbar/brightness +Date: August 2015 +KernelVersion: 4.2 +Description: + Writing to this file adjusts the overall brightness of + the lightbar, separate from any color intensity. The + valid range is 0 (off) to 255 (maximum brightness). + +What: /sys/class/chromeos//lightbar/interval_msec +Date: August 2015 +KernelVersion: 4.2 +Description: + The lightbar is controlled by an embedded controller (EC), + which also manages the keyboard, battery charging, fans, + and other system hardware. To prevent unprivileged users + from interfering with the other EC functions, the rate at + which the lightbar control files can be read or written is + limited. + + Reading this file will return the number of milliseconds + that must elapse between accessing any of the lightbar + functions through this interface. Going faster will simply + block until the necessary interval has lapsed. The interval + applies uniformly to all accesses of any kind by any user. + +What: /sys/class/chromeos//lightbar/led_rgb +Date: August 2015 +KernelVersion: 4.2 +Description: + This allows you to control each LED segment. If the + lightbar is already running one of the automatic + sequences, you probably won’t see anything change because + your color setting will be almost immediately replaced. + To get useful results, you should stop the lightbar + sequence first. + + The values written to this file are sets of four integers, + indicating LED, RED, GREEN, BLUE. The LED number is 0 to 3 + to select a single segment, or 4 to set all four segments + to the same value at once. The RED, GREEN, and BLUE + numbers should be in the range 0 (off) to 255 (maximum). + You can update more than one segment at a time by writing + more than one set of four integers. + +What: /sys/class/chromeos//lightbar/program +Date: August 2015 +KernelVersion: 4.2 +Description: + This allows you to upload and run custom lightbar sequences. + +What: /sys/class/chromeos//lightbar/sequence +Date: August 2015 +KernelVersion: 4.2 +Description: + The Pixel lightbar has a number of built-in sequences + that it displays under various conditions, such as at + power on, shut down, or while running. Reading from this + file displays the current sequence that the lightbar is + displaying. Writing to this file allows you to change the + sequence. + +What: /sys/class/chromeos//lightbar/userspace_control +Date: August 2015 +KernelVersion: 4.2 +Description: + This allows you to take the control of the lightbar. This + prevents the kernel from going through its normal + sequences. + +What: /sys/class/chromeos//lightbar/version +Date: August 2015 +KernelVersion: 4.2 +Description: + Show the information about the lightbar version. diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c index 2d0fee488c5a..b227718e0ec2 100644 --- a/drivers/mfd/cros_ec_dev.c +++ b/drivers/mfd/cros_ec_dev.c @@ -36,7 +36,6 @@ static int ec_major; static const struct attribute_group *cros_ec_groups[] = { &cros_ec_attr_group, - &cros_ec_lightbar_attr_group, &cros_ec_vbc_attr_group, NULL, }; @@ -395,6 +394,10 @@ static const struct mfd_cell cros_usbpd_charger_cells[] = { { .name = "cros-usbpd-charger" } }; +static const struct mfd_cell cros_ec_platform_cells[] = { + { .name = "cros-ec-lightbar" }, +}; + static int ec_device_probe(struct platform_device *pdev) { int retval = -ENOMEM; @@ -470,9 +473,6 @@ static int ec_device_probe(struct platform_device *pdev) retval); } - /* Take control of the lightbar from the EC. */ - lb_manual_suspend_ctrl(ec, 1); - /* We can now add the sysfs class, we know which parameter to show */ retval = cdev_device_add(&ec->cdev, &ec->class_dev); if (retval) { @@ -480,6 +480,15 @@ static int ec_device_probe(struct platform_device *pdev) goto failed; } + retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, + cros_ec_platform_cells, + ARRAY_SIZE(cros_ec_platform_cells), + NULL, 0, NULL); + if (retval) + dev_warn(ec->dev, + "failed to add cros-ec platform devices: %d\n", + retval); + if (cros_ec_debugfs_init(ec)) dev_warn(dev, "failed to create debugfs directory\n"); @@ -494,9 +503,6 @@ static int ec_device_remove(struct platform_device *pdev) { struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); - /* Let the EC take over the lightbar again. */ - lb_manual_suspend_ctrl(ec, 0); - cros_ec_debugfs_remove(ec); mfd_remove_devices(ec->dev); @@ -525,8 +531,6 @@ static __maybe_unused int ec_device_suspend(struct device *dev) cros_ec_debugfs_suspend(ec); - lb_suspend(ec); - return 0; } @@ -536,8 +540,6 @@ static __maybe_unused int ec_device_resume(struct device *dev) cros_ec_debugfs_resume(ec); - lb_resume(ec); - return 0; } diff --git a/drivers/mfd/cros_ec_dev.h b/drivers/mfd/cros_ec_dev.h index 978d836a0248..ec750433455a 100644 --- a/drivers/mfd/cros_ec_dev.h +++ b/drivers/mfd/cros_ec_dev.h @@ -44,10 +44,4 @@ struct cros_ec_readmem { #define CROS_EC_DEV_IOCXCMD _IOWR(CROS_EC_DEV_IOC, 0, struct cros_ec_command) #define CROS_EC_DEV_IOCRDMEM _IOWR(CROS_EC_DEV_IOC, 1, struct cros_ec_readmem) -/* Lightbar utilities */ -extern bool ec_has_lightbar(struct cros_ec_dev *ec); -extern int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable); -extern int lb_suspend(struct cros_ec_dev *ec); -extern int lb_resume(struct cros_ec_dev *ec); - #endif /* _CROS_EC_DEV_H_ */ diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig index 16b1615958aa..6c05752a3334 100644 --- a/drivers/platform/chrome/Kconfig +++ b/drivers/platform/chrome/Kconfig @@ -111,4 +111,15 @@ config CROS_KBD_LED_BACKLIGHT To compile this driver as a module, choose M here: the module will be called cros_kbd_led_backlight. +config CROS_EC_LIGHTBAR + tristate "Chromebook Pixel's lightbar support" + depends on MFD_CROS_EC_CHARDEV + default MFD_CROS_EC_CHARDEV + help + This option exposes the Chromebook Pixel's lightbar to + userspace. + + To compile this driver as a module, choose M here: the + module will be called cros_ec_lightbar. + endif # CHROMEOS_PLATFORMS diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile index cd591bf872bb..3c29a4b405d5 100644 --- a/drivers/platform/chrome/Makefile +++ b/drivers/platform/chrome/Makefile @@ -3,7 +3,7 @@ obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o -cros_ec_ctl-objs := cros_ec_sysfs.o cros_ec_lightbar.o \ +cros_ec_ctl-objs := cros_ec_sysfs.o \ cros_ec_vbc.o cros_ec_debugfs.o obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o @@ -13,3 +13,4 @@ cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o +obj-$(CONFIG_CROS_EC_LIGHTBAR) += cros_ec_lightbar.o diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c index 68193bb53383..80eed6317570 100644 --- a/drivers/platform/chrome/cros_ec_lightbar.c +++ b/drivers/platform/chrome/cros_ec_lightbar.c @@ -33,6 +33,8 @@ #include #include +#define DRV_NAME "cros-ec-lightbar" + /* Rate-limit the lightbar interface to prevent DoS. */ static unsigned long lb_interval_jiffies = 50 * HZ / 1000; @@ -373,7 +375,7 @@ static int lb_send_empty_cmd(struct cros_ec_dev *ec, uint8_t cmd) return ret; } -int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable) +static int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable) { struct ec_params_lightbar *param; struct cros_ec_command *msg; @@ -408,25 +410,6 @@ int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable) return ret; } -EXPORT_SYMBOL(lb_manual_suspend_ctrl); - -int lb_suspend(struct cros_ec_dev *ec) -{ - if (userspace_control || ec != ec_with_lightbar) - return 0; - - return lb_send_empty_cmd(ec, LIGHTBAR_CMD_SUSPEND); -} -EXPORT_SYMBOL(lb_suspend); - -int lb_resume(struct cros_ec_dev *ec) -{ - if (userspace_control || ec != ec_with_lightbar) - return 0; - - return lb_send_empty_cmd(ec, LIGHTBAR_CMD_RESUME); -} -EXPORT_SYMBOL(lb_resume); static ssize_t sequence_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) @@ -584,7 +567,7 @@ static struct attribute *__lb_cmds_attrs[] = { NULL, }; -bool ec_has_lightbar(struct cros_ec_dev *ec) +static bool ec_has_lightbar(struct cros_ec_dev *ec) { return !!get_lightbar_version(ec, NULL, NULL); } @@ -616,4 +599,72 @@ struct attribute_group cros_ec_lightbar_attr_group = { .attrs = __lb_cmds_attrs, .is_visible = cros_ec_lightbar_attrs_are_visible, }; -EXPORT_SYMBOL(cros_ec_lightbar_attr_group); + +static int cros_ec_lightbar_probe(struct platform_device *pd) +{ + struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent); + struct device *dev = &pd->dev; + int ret; + + /* Take control of the lightbar from the EC. */ + lb_manual_suspend_ctrl(ec_dev, 1); + + ret = sysfs_create_group(&ec_dev->class_dev.kobj, + &cros_ec_lightbar_attr_group); + if (ret < 0) + dev_err(dev, "failed to create %s attributes. err=%d\n", + cros_ec_lightbar_attr_group.name, ret); + + return ret; +} + +static int cros_ec_lightbar_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_lightbar_attr_group); + + /* Let the EC take over the lightbar again. */ + lb_manual_suspend_ctrl(ec_dev, 0); + + return 0; +} + +static int __maybe_unused cros_ec_lightbar_resume(struct device *dev) +{ + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev); + + if (userspace_control || ec_dev != ec_with_lightbar) + return 0; + + return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_RESUME); +} + +static int __maybe_unused cros_ec_lightbar_suspend(struct device *dev) +{ + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev); + + if (userspace_control || ec_dev != ec_with_lightbar) + return 0; + + return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_SUSPEND); +} + +static SIMPLE_DEV_PM_OPS(cros_ec_lightbar_pm_ops, + cros_ec_lightbar_suspend, cros_ec_lightbar_resume); + +static struct platform_driver cros_ec_lightbar_driver = { + .driver = { + .name = DRV_NAME, + .pm = &cros_ec_lightbar_pm_ops, + }, + .probe = cros_ec_lightbar_probe, + .remove = cros_ec_lightbar_remove, +}; + +module_platform_driver(cros_ec_lightbar_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Expose the Chromebook Pixel's lightbar to userspace"); +MODULE_ALIAS("platform:" DRV_NAME); diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h index 977ebaa78e99..1e9b569564ea 100644 --- a/include/linux/mfd/cros_ec.h +++ b/include/linux/mfd/cros_ec.h @@ -327,7 +327,6 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev); /* sysfs stuff */ extern struct attribute_group cros_ec_attr_group; -extern struct attribute_group cros_ec_lightbar_attr_group; extern struct attribute_group cros_ec_vbc_attr_group; /* debugfs stuff */