| Message ID | 20240613-cros_ec-led-v3-4-500b50f41e0f@weissschuh.net |
|---|---|
| State | New |
| Headers | show |
| Series | ChromeOS Embedded Controller LED driver | expand |
On Thu, 13 Jun 2024, Thomas Weißschuh wrote: > The ChromeOS Embedded Controller exposes an LED control command. > Expose its functionality through the leds subsystem. > > The LEDs are exposed as multicolor devices. > A hardware trigger, which is active by default, is provided to let the > EC itself take over control over the LED. > > The driver is designed to be probed via the cros_ec mfd device. > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > --- > MAINTAINERS | 5 + > drivers/leds/Kconfig | 15 +++ > drivers/leds/Makefile | 1 + > drivers/leds/leds-cros_ec.c | 299 ++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 320 insertions(+) Mostly fine. Couple of points. > diff --git a/MAINTAINERS b/MAINTAINERS > index aacccb376c28..8bc3491a08af 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -5135,6 +5135,11 @@ S: Maintained > F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml > F: sound/soc/codecs/cros_ec_codec.* > > +CHROMEOS EC LED DRIVER > +M: Thomas Weißschuh <thomas@weissschuh.net> > +S: Maintained > +F: drivers/leds/leds-cros_ec.c > + > CHROMEOS EC SUBDRIVERS > M: Benson Leung <bleung@chromium.org> > R: Guenter Roeck <groeck@chromium.org> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 05e6af88b88c..aa2fec9a34ed 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -179,6 +179,21 @@ config LEDS_CR0014114 > To compile this driver as a module, choose M here: the module > will be called leds-cr0014114. > > +config LEDS_CROS_EC > + tristate "LED Support for ChromeOS EC" > + depends on MFD_CROS_EC_DEV > + depends on LEDS_CLASS_MULTICOLOR > + select LEDS_TRIGGERS > + default MFD_CROS_EC_DEV > + help > + This option enables support for LEDs managed by ChromeOS ECs. > + All LEDs exposed by the EC are supported in multicolor mode. > + A hardware trigger to switch back to the automatic behaviour is > + provided. > + > + To compile this driver as a module, choose M here: the module > + will be called leds-cros_ec. > + > config LEDS_EL15203000 > tristate "LED Support for Crane EL15203000" > depends on LEDS_CLASS > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index effdfc6f1e95..3491904e13f7 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -26,6 +26,7 @@ obj-$(CONFIG_LEDS_CLEVO_MAIL) += leds-clevo-mail.o > obj-$(CONFIG_LEDS_COBALT_QUBE) += leds-cobalt-qube.o > obj-$(CONFIG_LEDS_COBALT_RAQ) += leds-cobalt-raq.o > obj-$(CONFIG_LEDS_CPCAP) += leds-cpcap.o > +obj-$(CONFIG_LEDS_CROS_EC) += leds-cros_ec.o > obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o > obj-$(CONFIG_LEDS_DA9052) += leds-da9052.o > obj-$(CONFIG_LEDS_GPIO) += leds-gpio.o > diff --git a/drivers/leds/leds-cros_ec.c b/drivers/leds/leds-cros_ec.c > new file mode 100644 > index 000000000000..7bb21a587713 > --- /dev/null > +++ b/drivers/leds/leds-cros_ec.c > @@ -0,0 +1,299 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * ChromeOS EC LED Driver > + * > + * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net> > + */ > + > +#include <linux/device.h> > +#include <linux/leds.h> > +#include <linux/led-class-multicolor.h> > +#include <linux/mod_devicetable.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/platform_data/cros_ec_commands.h> > +#include <linux/platform_data/cros_ec_proto.h> > + > +#define DRV_NAME "cros-ec-led" Please refrain from defining device names. Use the string in-place. > +static const char * const cros_ec_led_functions[] = { > + [EC_LED_ID_BATTERY_LED] = LED_FUNCTION_CHARGING, > + [EC_LED_ID_POWER_LED] = LED_FUNCTION_POWER, > + [EC_LED_ID_ADAPTER_LED] = "adapter", > + [EC_LED_ID_LEFT_LED] = "left", > + [EC_LED_ID_RIGHT_LED] = "right", > + [EC_LED_ID_RECOVERY_HW_REINIT_LED] = "recovery-hw-reinit", > + [EC_LED_ID_SYSRQ_DEBUG_LED] = "sysrq-debug", > +}; > + > +static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT); What does this do? Result in a build failure? > +static const int cros_ec_led_to_linux_id[] = { > + [EC_LED_COLOR_RED] = LED_COLOR_ID_RED, > + [EC_LED_COLOR_GREEN] = LED_COLOR_ID_GREEN, > + [EC_LED_COLOR_BLUE] = LED_COLOR_ID_BLUE, > + [EC_LED_COLOR_YELLOW] = LED_COLOR_ID_YELLOW, > + [EC_LED_COLOR_WHITE] = LED_COLOR_ID_WHITE, > + [EC_LED_COLOR_AMBER] = LED_COLOR_ID_AMBER, > +}; > + > +static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT); > + > +static const int cros_ec_linux_to_ec_id[] = { > + [LED_COLOR_ID_RED] = EC_LED_COLOR_RED, > + [LED_COLOR_ID_GREEN] = EC_LED_COLOR_GREEN, > + [LED_COLOR_ID_BLUE] = EC_LED_COLOR_BLUE, > + [LED_COLOR_ID_YELLOW] = EC_LED_COLOR_YELLOW, > + [LED_COLOR_ID_WHITE] = EC_LED_COLOR_WHITE, > + [LED_COLOR_ID_AMBER] = EC_LED_COLOR_AMBER, > +}; > + > +struct cros_ec_led_priv { > + struct led_classdev_mc led_mc_cdev; > + struct cros_ec_device *cros_ec; > + enum ec_led_id led_id; > +}; > + > +static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_classdev *led_cdev) > +{ > + return container_of(lcdev_to_mccdev(led_cdev), struct cros_ec_led_priv, led_mc_cdev); > +} > + > +union cros_ec_led_cmd_data { > + struct ec_params_led_control req; > + struct ec_response_led_control resp; > +} __packed; > + > +static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec, > + union cros_ec_led_cmd_data *arg) > +{ > + int ret; > + struct { > + struct cros_ec_command msg; > + union cros_ec_led_cmd_data data; > + } __packed buf = { > + .msg = { > + .version = 1, > + .command = EC_CMD_LED_CONTROL, > + .insize = sizeof(arg->resp), > + .outsize = sizeof(arg->req), > + }, > + .data.req = arg->req > + }; > + > + ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg); > + if (ret < 0) > + return ret; > + > + arg->resp = buf.data.resp; > + > + return 0; > +} > + > +static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev) > +{ > + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); > + union cros_ec_led_cmd_data arg = {}; > + > + arg.req.led_id = priv->led_id; > + arg.req.flags = EC_LED_FLAGS_AUTO; > + > + return cros_ec_led_send_cmd(priv->cros_ec, &arg); > +} > + > +static struct led_hw_trigger_type cros_ec_led_trigger_type; > + > +static struct led_trigger cros_ec_led_trigger = { > + .name = "chromeos-auto", > + .trigger_type = &cros_ec_led_trigger_type, > + .activate = cros_ec_led_trigger_activate, > +}; > + > +static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev, > + enum led_brightness brightness) > +{ > + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); > + union cros_ec_led_cmd_data arg = {}; > + enum ec_led_colors led_color; > + struct mc_subled *subled; > + size_t i; > + > + led_mc_calc_color_components(&priv->led_mc_cdev, brightness); > + > + arg.req.led_id = priv->led_id; > + > + for (i = 0; i < priv->led_mc_cdev.num_colors; i++) { > + subled = &priv->led_mc_cdev.subled_info[i]; > + led_color = cros_ec_linux_to_ec_id[subled->color_index]; > + arg.req.brightness[led_color] = subled->brightness; > + } > + > + return cros_ec_led_send_cmd(priv->cros_ec, &arg); > +} > + > +static int cros_ec_led_count_subleds(struct device *dev, > + struct ec_response_led_control *resp, > + unsigned int *max_brightness) > +{ > + unsigned int range, common_range = 0; > + int num_subleds = 0; > + size_t i; > + > + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { > + range = resp->brightness_range[i]; > + > + if (!range) > + continue; > + > + num_subleds++; > + > + if (!common_range) > + common_range = range; > + > + if (common_range != range) { > + /* The multicolor LED API expects a uniform max_brightness */ > + dev_warn(dev, "Inconsistent LED brightness values\n"); You shouldn't print a warning then return an error. Please upgrade to dev_err(). > + return -EINVAL; > + } > + } > + > + if (!num_subleds) > + return -EINVAL; > + > + *max_brightness = common_range; > + return num_subleds; > +} > + > +static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev) > +{ > + int color; > + > + if (led_mc_cdev->num_colors == 1) > + color = led_mc_cdev->subled_info[0].color_index; > + else > + color = LED_COLOR_ID_MULTI; > + > + return led_get_color_name(color); > +} > + > +static int cros_ec_led_probe_led(struct device *dev, struct cros_ec_device *cros_ec, Odd naming choice. How about cros_ec_led_probe_one() or cros_ec_led_init()? > + enum ec_led_id id) > +{ > + union cros_ec_led_cmd_data arg = {}; > + struct cros_ec_led_priv *priv; > + struct led_classdev *led_cdev; > + struct mc_subled *subleds; > + int ret, num_subleds; > + size_t i, subled; Why size_t for the iterator? > + arg.req.led_id = id; > + arg.req.flags = EC_LED_FLAGS_QUERY; > + ret = cros_ec_led_send_cmd(cros_ec, &arg); > + /* Unknown LED, skip */ Place the comment inside the if() or next to the return. > + if (ret == -EINVAL) > + return 0; > + if (ret == -EOPNOTSUPP) > + return -ENODEV; > + if (ret < 0) > + return ret; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + num_subleds = cros_ec_led_count_subleds(dev, &arg.resp, > + &priv->led_mc_cdev.led_cdev.max_brightness); > + if (num_subleds < 0) > + return num_subleds; > + > + priv->cros_ec = cros_ec; > + priv->led_id = id; > + > + subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL); > + if (!subleds) > + return -ENOMEM; > + > + subled = 0; > + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { > + if (!arg.resp.brightness_range[i]) > + continue; > + > + subleds[subled].color_index = cros_ec_led_to_linux_id[i]; > + if (subled == 0) > + subleds[subled].intensity = 100; > + subled++; > + } > + > + priv->led_mc_cdev.subled_info = subleds; > + priv->led_mc_cdev.num_colors = num_subleds; > + > + led_cdev = &priv->led_mc_cdev.led_cdev; > + led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking; > + led_cdev->trigger_type = &cros_ec_led_trigger_type; > + led_cdev->default_trigger = cros_ec_led_trigger.name; > + led_cdev->hw_control_trigger = cros_ec_led_trigger.name; > + > + led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s", > + cros_ec_led_get_color_name(&priv->led_mc_cdev), > + cros_ec_led_functions[id]); > + if (!led_cdev->name) > + return -ENOMEM; > + > + return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev); > +} > + > +static int cros_ec_led_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); > + struct cros_ec_device *cros_ec = ec_dev->ec_dev; > + int ret = 0; > + size_t i; > + > + for (i = 0; i < EC_LED_ID_COUNT; i++) { > + ret = cros_ec_led_probe_led(dev, cros_ec, i); > + if (ret) > + break; > + } > + > + return ret; > +} > + > +static const struct platform_device_id cros_ec_led_id[] = { > + { DRV_NAME, 0 }, > + {} > +}; > + > +static struct platform_driver cros_ec_led_driver = { > + .driver.name = DRV_NAME, > + .probe = cros_ec_led_probe, > + .id_table = cros_ec_led_id, > +}; > + > +static int __init cros_ec_led_init(void) > +{ > + int ret; > + > + ret = led_trigger_register(&cros_ec_led_trigger); > + if (ret) > + return ret; This has to be done before probe? > + ret = platform_driver_register(&cros_ec_led_driver); > + if (ret) > + led_trigger_unregister(&cros_ec_led_trigger); > + > + return ret; > +}; > +module_init(cros_ec_led_init); > + > +static void __exit cros_ec_led_exit(void) > +{ > + platform_driver_unregister(&cros_ec_led_driver); > + led_trigger_unregister(&cros_ec_led_trigger); > +}; > +module_exit(cros_ec_led_exit); > + > +MODULE_DEVICE_TABLE(platform, cros_ec_led_id); > +MODULE_DESCRIPTION("ChromeOS EC LED Driver"); > +MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net"); > +MODULE_LICENSE("GPL"); > > -- > 2.45.2 >
On 2024-06-14 10:02:19+0000, Lee Jones wrote: > On Thu, 13 Jun 2024, Thomas Weißschuh wrote: > > > The ChromeOS Embedded Controller exposes an LED control command. > > Expose its functionality through the leds subsystem. > > > > The LEDs are exposed as multicolor devices. > > A hardware trigger, which is active by default, is provided to let the > > EC itself take over control over the LED. > > > > The driver is designed to be probed via the cros_ec mfd device. > > > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > > --- > > MAINTAINERS | 5 + > > drivers/leds/Kconfig | 15 +++ > > drivers/leds/Makefile | 1 + > > drivers/leds/leds-cros_ec.c | 299 ++++++++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 320 insertions(+) > > Mostly fine. Couple of points. > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index aacccb376c28..8bc3491a08af 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -5135,6 +5135,11 @@ S: Maintained > > F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml > > F: sound/soc/codecs/cros_ec_codec.* > > > > +CHROMEOS EC LED DRIVER > > +M: Thomas Weißschuh <thomas@weissschuh.net> > > +S: Maintained > > +F: drivers/leds/leds-cros_ec.c > > + > > CHROMEOS EC SUBDRIVERS > > M: Benson Leung <bleung@chromium.org> > > R: Guenter Roeck <groeck@chromium.org> > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > > index 05e6af88b88c..aa2fec9a34ed 100644 > > --- a/drivers/leds/Kconfig > > +++ b/drivers/leds/Kconfig > > @@ -179,6 +179,21 @@ config LEDS_CR0014114 > > To compile this driver as a module, choose M here: the module > > will be called leds-cr0014114. > > > > +config LEDS_CROS_EC > > + tristate "LED Support for ChromeOS EC" > > + depends on MFD_CROS_EC_DEV > > + depends on LEDS_CLASS_MULTICOLOR > > + select LEDS_TRIGGERS > > + default MFD_CROS_EC_DEV > > + help > > + This option enables support for LEDs managed by ChromeOS ECs. > > + All LEDs exposed by the EC are supported in multicolor mode. > > + A hardware trigger to switch back to the automatic behaviour is > > + provided. > > + > > + To compile this driver as a module, choose M here: the module > > + will be called leds-cros_ec. > > + > > config LEDS_EL15203000 > > tristate "LED Support for Crane EL15203000" > > depends on LEDS_CLASS > > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > > index effdfc6f1e95..3491904e13f7 100644 > > --- a/drivers/leds/Makefile > > +++ b/drivers/leds/Makefile > > @@ -26,6 +26,7 @@ obj-$(CONFIG_LEDS_CLEVO_MAIL) += leds-clevo-mail.o > > obj-$(CONFIG_LEDS_COBALT_QUBE) += leds-cobalt-qube.o > > obj-$(CONFIG_LEDS_COBALT_RAQ) += leds-cobalt-raq.o > > obj-$(CONFIG_LEDS_CPCAP) += leds-cpcap.o > > +obj-$(CONFIG_LEDS_CROS_EC) += leds-cros_ec.o > > obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o > > obj-$(CONFIG_LEDS_DA9052) += leds-da9052.o > > obj-$(CONFIG_LEDS_GPIO) += leds-gpio.o > > diff --git a/drivers/leds/leds-cros_ec.c b/drivers/leds/leds-cros_ec.c > > new file mode 100644 > > index 000000000000..7bb21a587713 > > --- /dev/null > > +++ b/drivers/leds/leds-cros_ec.c > > @@ -0,0 +1,299 @@ > > +// SPDX-License-Identifier: GPL-2.0-or-later > > +/* > > + * ChromeOS EC LED Driver > > + * > > + * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net> > > + */ > > + > > +#include <linux/device.h> > > +#include <linux/leds.h> > > +#include <linux/led-class-multicolor.h> > > +#include <linux/mod_devicetable.h> > > +#include <linux/module.h> > > +#include <linux/platform_device.h> > > +#include <linux/platform_data/cros_ec_commands.h> > > +#include <linux/platform_data/cros_ec_proto.h> > > + > > +#define DRV_NAME "cros-ec-led" > > Please refrain from defining device names. Use the string in-place. This is the common pattern used for other drivers using the cros_ec MFD device. I'll change it, though. > > +static const char * const cros_ec_led_functions[] = { > > + [EC_LED_ID_BATTERY_LED] = LED_FUNCTION_CHARGING, > > + [EC_LED_ID_POWER_LED] = LED_FUNCTION_POWER, > > + [EC_LED_ID_ADAPTER_LED] = "adapter", > > + [EC_LED_ID_LEFT_LED] = "left", > > + [EC_LED_ID_RIGHT_LED] = "right", > > + [EC_LED_ID_RECOVERY_HW_REINIT_LED] = "recovery-hw-reinit", > > + [EC_LED_ID_SYSRQ_DEBUG_LED] = "sysrq-debug", > > +}; > > + > > +static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT); > > What does this do? Result in a build failure? Yes. It's the standard C version of BUILD_BUG_ON(). It can be used in all contexts, in contrast to BUILD_BUG_ON) and is already widely used within the tree. The goal is to make sure that additions to "enum ec_led_id" do not inadvertedly lead to out-of-bounds accesses in those arrays. > > +static const int cros_ec_led_to_linux_id[] = { > > + [EC_LED_COLOR_RED] = LED_COLOR_ID_RED, > > + [EC_LED_COLOR_GREEN] = LED_COLOR_ID_GREEN, > > + [EC_LED_COLOR_BLUE] = LED_COLOR_ID_BLUE, > > + [EC_LED_COLOR_YELLOW] = LED_COLOR_ID_YELLOW, > > + [EC_LED_COLOR_WHITE] = LED_COLOR_ID_WHITE, > > + [EC_LED_COLOR_AMBER] = LED_COLOR_ID_AMBER, > > +}; > > + > > +static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT); > > + > > +static const int cros_ec_linux_to_ec_id[] = { > > + [LED_COLOR_ID_RED] = EC_LED_COLOR_RED, > > + [LED_COLOR_ID_GREEN] = EC_LED_COLOR_GREEN, > > + [LED_COLOR_ID_BLUE] = EC_LED_COLOR_BLUE, > > + [LED_COLOR_ID_YELLOW] = EC_LED_COLOR_YELLOW, > > + [LED_COLOR_ID_WHITE] = EC_LED_COLOR_WHITE, > > + [LED_COLOR_ID_AMBER] = EC_LED_COLOR_AMBER, > > +}; > > + > > +struct cros_ec_led_priv { > > + struct led_classdev_mc led_mc_cdev; > > + struct cros_ec_device *cros_ec; > > + enum ec_led_id led_id; > > +}; > > + > > +static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_classdev *led_cdev) > > +{ > > + return container_of(lcdev_to_mccdev(led_cdev), struct cros_ec_led_priv, led_mc_cdev); > > +} > > + > > +union cros_ec_led_cmd_data { > > + struct ec_params_led_control req; > > + struct ec_response_led_control resp; > > +} __packed; > > + > > +static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec, > > + union cros_ec_led_cmd_data *arg) > > +{ > > + int ret; > > + struct { > > + struct cros_ec_command msg; > > + union cros_ec_led_cmd_data data; > > + } __packed buf = { > > + .msg = { > > + .version = 1, > > + .command = EC_CMD_LED_CONTROL, > > + .insize = sizeof(arg->resp), > > + .outsize = sizeof(arg->req), > > + }, > > + .data.req = arg->req > > + }; > > + > > + ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg); > > + if (ret < 0) > > + return ret; > > + > > + arg->resp = buf.data.resp; > > + > > + return 0; > > +} > > + > > +static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev) > > +{ > > + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); > > + union cros_ec_led_cmd_data arg = {}; > > + > > + arg.req.led_id = priv->led_id; > > + arg.req.flags = EC_LED_FLAGS_AUTO; > > + > > + return cros_ec_led_send_cmd(priv->cros_ec, &arg); > > +} > > + > > +static struct led_hw_trigger_type cros_ec_led_trigger_type; > > + > > +static struct led_trigger cros_ec_led_trigger = { > > + .name = "chromeos-auto", > > + .trigger_type = &cros_ec_led_trigger_type, > > + .activate = cros_ec_led_trigger_activate, > > +}; > > + > > +static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev, > > + enum led_brightness brightness) > > +{ > > + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); > > + union cros_ec_led_cmd_data arg = {}; > > + enum ec_led_colors led_color; > > + struct mc_subled *subled; > > + size_t i; > > + > > + led_mc_calc_color_components(&priv->led_mc_cdev, brightness); > > + > > + arg.req.led_id = priv->led_id; > > + > > + for (i = 0; i < priv->led_mc_cdev.num_colors; i++) { > > + subled = &priv->led_mc_cdev.subled_info[i]; > > + led_color = cros_ec_linux_to_ec_id[subled->color_index]; > > + arg.req.brightness[led_color] = subled->brightness; > > + } > > + > > + return cros_ec_led_send_cmd(priv->cros_ec, &arg); > > +} > > + > > +static int cros_ec_led_count_subleds(struct device *dev, > > + struct ec_response_led_control *resp, > > + unsigned int *max_brightness) > > +{ > > + unsigned int range, common_range = 0; > > + int num_subleds = 0; > > + size_t i; > > + > > + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { > > + range = resp->brightness_range[i]; > > + > > + if (!range) > > + continue; > > + > > + num_subleds++; > > + > > + if (!common_range) > > + common_range = range; > > + > > + if (common_range != range) { > > + /* The multicolor LED API expects a uniform max_brightness */ > > + dev_warn(dev, "Inconsistent LED brightness values\n"); > > You shouldn't print a warning then return an error. > > Please upgrade to dev_err(). Ack. > > + return -EINVAL; > > + } > > + } > > + > > + if (!num_subleds) > > + return -EINVAL; > > + > > + *max_brightness = common_range; > > + return num_subleds; > > +} > > + > > +static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev) > > +{ > > + int color; > > + > > + if (led_mc_cdev->num_colors == 1) > > + color = led_mc_cdev->subled_info[0].color_index; > > + else > > + color = LED_COLOR_ID_MULTI; > > + > > + return led_get_color_name(color); > > +} > > + > > +static int cros_ec_led_probe_led(struct device *dev, struct cros_ec_device *cros_ec, > > Odd naming choice. > > How about cros_ec_led_probe_one() or cros_ec_led_init()? Ack. > > + enum ec_led_id id) > > +{ > > + union cros_ec_led_cmd_data arg = {}; > > + struct cros_ec_led_priv *priv; > > + struct led_classdev *led_cdev; > > + struct mc_subled *subleds; > > + int ret, num_subleds; > > + size_t i, subled; > > Why size_t for the iterator? Habit, because ARRAY_SIZE() returns size_t. Will change to int. > > + arg.req.led_id = id; > > + arg.req.flags = EC_LED_FLAGS_QUERY; > > + ret = cros_ec_led_send_cmd(cros_ec, &arg); > > + /* Unknown LED, skip */ > > Place the comment inside the if() or next to the return. Ack. > > + if (ret == -EINVAL) > > + return 0; > > + if (ret == -EOPNOTSUPP) > > + return -ENODEV; > > + if (ret < 0) > > + return ret; > > + > > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > > + if (!priv) > > + return -ENOMEM; > > + > > + num_subleds = cros_ec_led_count_subleds(dev, &arg.resp, > > + &priv->led_mc_cdev.led_cdev.max_brightness); > > + if (num_subleds < 0) > > + return num_subleds; > > + > > + priv->cros_ec = cros_ec; > > + priv->led_id = id; > > + > > + subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL); > > + if (!subleds) > > + return -ENOMEM; > > + > > + subled = 0; > > + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { > > + if (!arg.resp.brightness_range[i]) > > + continue; > > + > > + subleds[subled].color_index = cros_ec_led_to_linux_id[i]; > > + if (subled == 0) > > + subleds[subled].intensity = 100; > > + subled++; > > + } > > + > > + priv->led_mc_cdev.subled_info = subleds; > > + priv->led_mc_cdev.num_colors = num_subleds; > > + > > + led_cdev = &priv->led_mc_cdev.led_cdev; > > + led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking; > > + led_cdev->trigger_type = &cros_ec_led_trigger_type; > > + led_cdev->default_trigger = cros_ec_led_trigger.name; > > + led_cdev->hw_control_trigger = cros_ec_led_trigger.name; > > + > > + led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s", > > + cros_ec_led_get_color_name(&priv->led_mc_cdev), > > + cros_ec_led_functions[id]); > > + if (!led_cdev->name) > > + return -ENOMEM; > > + > > + return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev); > > +} > > + > > +static int cros_ec_led_probe(struct platform_device *pdev) > > +{ > > + struct device *dev = &pdev->dev; > > + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); > > + struct cros_ec_device *cros_ec = ec_dev->ec_dev; > > + int ret = 0; > > + size_t i; > > + > > + for (i = 0; i < EC_LED_ID_COUNT; i++) { > > + ret = cros_ec_led_probe_led(dev, cros_ec, i); > > + if (ret) > > + break; > > + } > > + > > + return ret; > > +} > > + > > +static const struct platform_device_id cros_ec_led_id[] = { > > + { DRV_NAME, 0 }, > > + {} > > +}; > > + > > +static struct platform_driver cros_ec_led_driver = { > > + .driver.name = DRV_NAME, > > + .probe = cros_ec_led_probe, > > + .id_table = cros_ec_led_id, > > +}; > > + > > +static int __init cros_ec_led_init(void) > > +{ > > + int ret; > > + > > + ret = led_trigger_register(&cros_ec_led_trigger); > > + if (ret) > > + return ret; > > This has to be done before probe? Nope, I think the can be moved into probe. It makes everything easier. > > + ret = platform_driver_register(&cros_ec_led_driver); > > + if (ret) > > + led_trigger_unregister(&cros_ec_led_trigger); > > + > > + return ret; > > +}; > > +module_init(cros_ec_led_init); > > + > > +static void __exit cros_ec_led_exit(void) > > +{ > > + platform_driver_unregister(&cros_ec_led_driver); > > + led_trigger_unregister(&cros_ec_led_trigger); > > +}; > > +module_exit(cros_ec_led_exit); > > + > > +MODULE_DEVICE_TABLE(platform, cros_ec_led_id); > > +MODULE_DESCRIPTION("ChromeOS EC LED Driver"); > > +MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net"); > > +MODULE_LICENSE("GPL"); > > > > -- > > 2.45.2 > > > > -- > Lee Jones [李琼斯]
On Fri, 14 Jun 2024, Thomas Weißschuh wrote: > On 2024-06-14 10:02:19+0000, Lee Jones wrote: > > On Thu, 13 Jun 2024, Thomas Weißschuh wrote: > > > > > The ChromeOS Embedded Controller exposes an LED control command. > > > Expose its functionality through the leds subsystem. > > > > > > The LEDs are exposed as multicolor devices. > > > A hardware trigger, which is active by default, is provided to let the > > > EC itself take over control over the LED. > > > > > > The driver is designed to be probed via the cros_ec mfd device. > > > > > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > > > --- > > > MAINTAINERS | 5 + > > > drivers/leds/Kconfig | 15 +++ > > > drivers/leds/Makefile | 1 + > > > drivers/leds/leds-cros_ec.c | 299 ++++++++++++++++++++++++++++++++++++++++++++ > > > 4 files changed, 320 insertions(+) > > > > Mostly fine. Couple of points. > > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > > index aacccb376c28..8bc3491a08af 100644 > > > --- a/MAINTAINERS > > > +++ b/MAINTAINERS > > > @@ -5135,6 +5135,11 @@ S: Maintained > > > F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml > > > F: sound/soc/codecs/cros_ec_codec.* > > > > > > +CHROMEOS EC LED DRIVER > > > +M: Thomas Weißschuh <thomas@weissschuh.net> > > > +S: Maintained > > > +F: drivers/leds/leds-cros_ec.c > > > + > > > CHROMEOS EC SUBDRIVERS > > > M: Benson Leung <bleung@chromium.org> > > > R: Guenter Roeck <groeck@chromium.org> > > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > > > index 05e6af88b88c..aa2fec9a34ed 100644 > > > --- a/drivers/leds/Kconfig > > > +++ b/drivers/leds/Kconfig > > > @@ -179,6 +179,21 @@ config LEDS_CR0014114 > > > To compile this driver as a module, choose M here: the module > > > will be called leds-cr0014114. > > > > > > +config LEDS_CROS_EC > > > + tristate "LED Support for ChromeOS EC" > > > + depends on MFD_CROS_EC_DEV > > > + depends on LEDS_CLASS_MULTICOLOR > > > + select LEDS_TRIGGERS > > > + default MFD_CROS_EC_DEV > > > + help > > > + This option enables support for LEDs managed by ChromeOS ECs. > > > + All LEDs exposed by the EC are supported in multicolor mode. > > > + A hardware trigger to switch back to the automatic behaviour is > > > + provided. > > > + > > > + To compile this driver as a module, choose M here: the module > > > + will be called leds-cros_ec. > > > + > > > config LEDS_EL15203000 > > > tristate "LED Support for Crane EL15203000" > > > depends on LEDS_CLASS > > > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > > > index effdfc6f1e95..3491904e13f7 100644 > > > --- a/drivers/leds/Makefile > > > +++ b/drivers/leds/Makefile > > > @@ -26,6 +26,7 @@ obj-$(CONFIG_LEDS_CLEVO_MAIL) += leds-clevo-mail.o > > > obj-$(CONFIG_LEDS_COBALT_QUBE) += leds-cobalt-qube.o > > > obj-$(CONFIG_LEDS_COBALT_RAQ) += leds-cobalt-raq.o > > > obj-$(CONFIG_LEDS_CPCAP) += leds-cpcap.o > > > +obj-$(CONFIG_LEDS_CROS_EC) += leds-cros_ec.o > > > obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o > > > obj-$(CONFIG_LEDS_DA9052) += leds-da9052.o > > > obj-$(CONFIG_LEDS_GPIO) += leds-gpio.o > > > diff --git a/drivers/leds/leds-cros_ec.c b/drivers/leds/leds-cros_ec.c > > > new file mode 100644 > > > index 000000000000..7bb21a587713 > > > --- /dev/null > > > +++ b/drivers/leds/leds-cros_ec.c > > > @@ -0,0 +1,299 @@ > > > +// SPDX-License-Identifier: GPL-2.0-or-later > > > +/* > > > + * ChromeOS EC LED Driver > > > + * > > > + * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net> > > > + */ > > > + > > > +#include <linux/device.h> > > > +#include <linux/leds.h> > > > +#include <linux/led-class-multicolor.h> > > > +#include <linux/mod_devicetable.h> > > > +#include <linux/module.h> > > > +#include <linux/platform_device.h> > > > +#include <linux/platform_data/cros_ec_commands.h> > > > +#include <linux/platform_data/cros_ec_proto.h> > > > + > > > +#define DRV_NAME "cros-ec-led" > > > > Please refrain from defining device names. Use the string in-place. > > This is the common pattern used for other drivers using the cros_ec MFD > device. I'll change it, though. And the others ideally. ;) > > > +static const char * const cros_ec_led_functions[] = { > > > + [EC_LED_ID_BATTERY_LED] = LED_FUNCTION_CHARGING, > > > + [EC_LED_ID_POWER_LED] = LED_FUNCTION_POWER, > > > + [EC_LED_ID_ADAPTER_LED] = "adapter", > > > + [EC_LED_ID_LEFT_LED] = "left", > > > + [EC_LED_ID_RIGHT_LED] = "right", > > > + [EC_LED_ID_RECOVERY_HW_REINIT_LED] = "recovery-hw-reinit", > > > + [EC_LED_ID_SYSRQ_DEBUG_LED] = "sysrq-debug", > > > +}; > > > + > > > +static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT); > > > > What does this do? Result in a build failure? > > Yes. It's the standard C version of BUILD_BUG_ON(). > It can be used in all contexts, in contrast to BUILD_BUG_ON) and is > already widely used within the tree. I see. Thanks for the explanation. > The goal is to make sure that additions to "enum ec_led_id" do not > inadvertedly lead to out-of-bounds accesses in those arrays. > > > > +static const int cros_ec_led_to_linux_id[] = { > > > + [EC_LED_COLOR_RED] = LED_COLOR_ID_RED, > > > + [EC_LED_COLOR_GREEN] = LED_COLOR_ID_GREEN, > > > + [EC_LED_COLOR_BLUE] = LED_COLOR_ID_BLUE, > > > + [EC_LED_COLOR_YELLOW] = LED_COLOR_ID_YELLOW, > > > + [EC_LED_COLOR_WHITE] = LED_COLOR_ID_WHITE, > > > + [EC_LED_COLOR_AMBER] = LED_COLOR_ID_AMBER, > > > +}; > > > + > > > +static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT); > > > + > > > +static const int cros_ec_linux_to_ec_id[] = { > > > + [LED_COLOR_ID_RED] = EC_LED_COLOR_RED, > > > + [LED_COLOR_ID_GREEN] = EC_LED_COLOR_GREEN, > > > + [LED_COLOR_ID_BLUE] = EC_LED_COLOR_BLUE, > > > + [LED_COLOR_ID_YELLOW] = EC_LED_COLOR_YELLOW, > > > + [LED_COLOR_ID_WHITE] = EC_LED_COLOR_WHITE, > > > + [LED_COLOR_ID_AMBER] = EC_LED_COLOR_AMBER, > > > +}; > > > + > > > +struct cros_ec_led_priv { > > > + struct led_classdev_mc led_mc_cdev; > > > + struct cros_ec_device *cros_ec; > > > + enum ec_led_id led_id; > > > +}; > > > + > > > +static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_classdev *led_cdev) > > > +{ > > > + return container_of(lcdev_to_mccdev(led_cdev), struct cros_ec_led_priv, led_mc_cdev); > > > +} > > > + > > > +union cros_ec_led_cmd_data { > > > + struct ec_params_led_control req; > > > + struct ec_response_led_control resp; > > > +} __packed; > > > + > > > +static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec, > > > + union cros_ec_led_cmd_data *arg) > > > +{ > > > + int ret; > > > + struct { > > > + struct cros_ec_command msg; > > > + union cros_ec_led_cmd_data data; > > > + } __packed buf = { > > > + .msg = { > > > + .version = 1, > > > + .command = EC_CMD_LED_CONTROL, > > > + .insize = sizeof(arg->resp), > > > + .outsize = sizeof(arg->req), > > > + }, > > > + .data.req = arg->req > > > + }; > > > + > > > + ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg); > > > + if (ret < 0) > > > + return ret; > > > + > > > + arg->resp = buf.data.resp; > > > + > > > + return 0; > > > +} > > > + > > > +static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev) > > > +{ > > > + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); > > > + union cros_ec_led_cmd_data arg = {}; > > > + > > > + arg.req.led_id = priv->led_id; > > > + arg.req.flags = EC_LED_FLAGS_AUTO; > > > + > > > + return cros_ec_led_send_cmd(priv->cros_ec, &arg); > > > +} > > > + > > > +static struct led_hw_trigger_type cros_ec_led_trigger_type; > > > + > > > +static struct led_trigger cros_ec_led_trigger = { > > > + .name = "chromeos-auto", > > > + .trigger_type = &cros_ec_led_trigger_type, > > > + .activate = cros_ec_led_trigger_activate, > > > +}; > > > + > > > +static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev, > > > + enum led_brightness brightness) > > > +{ > > > + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); > > > + union cros_ec_led_cmd_data arg = {}; > > > + enum ec_led_colors led_color; > > > + struct mc_subled *subled; > > > + size_t i; > > > + > > > + led_mc_calc_color_components(&priv->led_mc_cdev, brightness); > > > + > > > + arg.req.led_id = priv->led_id; > > > + > > > + for (i = 0; i < priv->led_mc_cdev.num_colors; i++) { > > > + subled = &priv->led_mc_cdev.subled_info[i]; > > > + led_color = cros_ec_linux_to_ec_id[subled->color_index]; > > > + arg.req.brightness[led_color] = subled->brightness; > > > + } > > > + > > > + return cros_ec_led_send_cmd(priv->cros_ec, &arg); > > > +} > > > + > > > +static int cros_ec_led_count_subleds(struct device *dev, > > > + struct ec_response_led_control *resp, > > > + unsigned int *max_brightness) > > > +{ > > > + unsigned int range, common_range = 0; > > > + int num_subleds = 0; > > > + size_t i; > > > + > > > + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { > > > + range = resp->brightness_range[i]; > > > + > > > + if (!range) > > > + continue; > > > + > > > + num_subleds++; > > > + > > > + if (!common_range) > > > + common_range = range; > > > + > > > + if (common_range != range) { > > > + /* The multicolor LED API expects a uniform max_brightness */ > > > + dev_warn(dev, "Inconsistent LED brightness values\n"); > > > > You shouldn't print a warning then return an error. > > > > Please upgrade to dev_err(). > > Ack. > > > > + return -EINVAL; > > > + } > > > + } > > > + > > > + if (!num_subleds) > > > + return -EINVAL; > > > + > > > + *max_brightness = common_range; > > > + return num_subleds; > > > +} > > > + > > > +static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev) > > > +{ > > > + int color; > > > + > > > + if (led_mc_cdev->num_colors == 1) > > > + color = led_mc_cdev->subled_info[0].color_index; > > > + else > > > + color = LED_COLOR_ID_MULTI; > > > + > > > + return led_get_color_name(color); > > > +} > > > + > > > +static int cros_ec_led_probe_led(struct device *dev, struct cros_ec_device *cros_ec, > > > > Odd naming choice. > > > > How about cros_ec_led_probe_one() or cros_ec_led_init()? > > Ack. > > > > + enum ec_led_id id) > > > +{ > > > + union cros_ec_led_cmd_data arg = {}; > > > + struct cros_ec_led_priv *priv; > > > + struct led_classdev *led_cdev; > > > + struct mc_subled *subleds; > > > + int ret, num_subleds; > > > + size_t i, subled; > > > > Why size_t for the iterator? > > Habit, because ARRAY_SIZE() returns size_t. > Will change to int. And the one below please. > > > + arg.req.led_id = id; > > > + arg.req.flags = EC_LED_FLAGS_QUERY; > > > + ret = cros_ec_led_send_cmd(cros_ec, &arg); > > > + /* Unknown LED, skip */ > > > > Place the comment inside the if() or next to the return. > > Ack. > > > > + if (ret == -EINVAL) > > > + return 0; > > > + if (ret == -EOPNOTSUPP) > > > + return -ENODEV; > > > + if (ret < 0) > > > + return ret; > > > + > > > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > > > + if (!priv) > > > + return -ENOMEM; > > > + > > > + num_subleds = cros_ec_led_count_subleds(dev, &arg.resp, > > > + &priv->led_mc_cdev.led_cdev.max_brightness); > > > + if (num_subleds < 0) > > > + return num_subleds; > > > + > > > + priv->cros_ec = cros_ec; > > > + priv->led_id = id; > > > + > > > + subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL); > > > + if (!subleds) > > > + return -ENOMEM; > > > + > > > + subled = 0; > > > + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { > > > + if (!arg.resp.brightness_range[i]) > > > + continue; > > > + > > > + subleds[subled].color_index = cros_ec_led_to_linux_id[i]; > > > + if (subled == 0) > > > + subleds[subled].intensity = 100; > > > + subled++; > > > + } > > > + > > > + priv->led_mc_cdev.subled_info = subleds; > > > + priv->led_mc_cdev.num_colors = num_subleds; > > > + > > > + led_cdev = &priv->led_mc_cdev.led_cdev; > > > + led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking; > > > + led_cdev->trigger_type = &cros_ec_led_trigger_type; > > > + led_cdev->default_trigger = cros_ec_led_trigger.name; > > > + led_cdev->hw_control_trigger = cros_ec_led_trigger.name; > > > + > > > + led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s", > > > + cros_ec_led_get_color_name(&priv->led_mc_cdev), > > > + cros_ec_led_functions[id]); > > > + if (!led_cdev->name) > > > + return -ENOMEM; > > > + > > > + return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev); > > > +} > > > + > > > +static int cros_ec_led_probe(struct platform_device *pdev) > > > +{ > > > + struct device *dev = &pdev->dev; > > > + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); > > > + struct cros_ec_device *cros_ec = ec_dev->ec_dev; > > > + int ret = 0; > > > + size_t i; > > > + > > > + for (i = 0; i < EC_LED_ID_COUNT; i++) { > > > + ret = cros_ec_led_probe_led(dev, cros_ec, i); > > > + if (ret) > > > + break; > > > + } > > > + > > > + return ret; > > > +} > > > + > > > +static const struct platform_device_id cros_ec_led_id[] = { > > > + { DRV_NAME, 0 }, > > > + {} > > > +}; > > > + > > > +static struct platform_driver cros_ec_led_driver = { > > > + .driver.name = DRV_NAME, > > > + .probe = cros_ec_led_probe, > > > + .id_table = cros_ec_led_id, > > > +}; > > > + > > > +static int __init cros_ec_led_init(void) > > > +{ > > > + int ret; > > > + > > > + ret = led_trigger_register(&cros_ec_led_trigger); > > > + if (ret) > > > + return ret; > > > > This has to be done before probe? > > Nope, I think the can be moved into probe. > It makes everything easier. Then you get rid of the boilerplate? > > > + ret = platform_driver_register(&cros_ec_led_driver); > > > + if (ret) > > > + led_trigger_unregister(&cros_ec_led_trigger); > > > + > > > + return ret; > > > +}; > > > +module_init(cros_ec_led_init); > > > + > > > +static void __exit cros_ec_led_exit(void) > > > +{ > > > + platform_driver_unregister(&cros_ec_led_driver); > > > + led_trigger_unregister(&cros_ec_led_trigger); > > > +}; > > > +module_exit(cros_ec_led_exit); > > > + > > > +MODULE_DEVICE_TABLE(platform, cros_ec_led_id); > > > +MODULE_DESCRIPTION("ChromeOS EC LED Driver"); > > > +MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net"); > > > +MODULE_LICENSE("GPL");
diff --git a/MAINTAINERS b/MAINTAINERS index aacccb376c28..8bc3491a08af 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5135,6 +5135,11 @@ S: Maintained F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml F: sound/soc/codecs/cros_ec_codec.* +CHROMEOS EC LED DRIVER +M: Thomas Weißschuh <thomas@weissschuh.net> +S: Maintained +F: drivers/leds/leds-cros_ec.c + CHROMEOS EC SUBDRIVERS M: Benson Leung <bleung@chromium.org> R: Guenter Roeck <groeck@chromium.org> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 05e6af88b88c..aa2fec9a34ed 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -179,6 +179,21 @@ config LEDS_CR0014114 To compile this driver as a module, choose M here: the module will be called leds-cr0014114. +config LEDS_CROS_EC + tristate "LED Support for ChromeOS EC" + depends on MFD_CROS_EC_DEV + depends on LEDS_CLASS_MULTICOLOR + select LEDS_TRIGGERS + default MFD_CROS_EC_DEV + help + This option enables support for LEDs managed by ChromeOS ECs. + All LEDs exposed by the EC are supported in multicolor mode. + A hardware trigger to switch back to the automatic behaviour is + provided. + + To compile this driver as a module, choose M here: the module + will be called leds-cros_ec. + config LEDS_EL15203000 tristate "LED Support for Crane EL15203000" depends on LEDS_CLASS diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index effdfc6f1e95..3491904e13f7 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -26,6 +26,7 @@ obj-$(CONFIG_LEDS_CLEVO_MAIL) += leds-clevo-mail.o obj-$(CONFIG_LEDS_COBALT_QUBE) += leds-cobalt-qube.o obj-$(CONFIG_LEDS_COBALT_RAQ) += leds-cobalt-raq.o obj-$(CONFIG_LEDS_CPCAP) += leds-cpcap.o +obj-$(CONFIG_LEDS_CROS_EC) += leds-cros_ec.o obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o obj-$(CONFIG_LEDS_DA9052) += leds-da9052.o obj-$(CONFIG_LEDS_GPIO) += leds-gpio.o diff --git a/drivers/leds/leds-cros_ec.c b/drivers/leds/leds-cros_ec.c new file mode 100644 index 000000000000..7bb21a587713 --- /dev/null +++ b/drivers/leds/leds-cros_ec.c @@ -0,0 +1,299 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ChromeOS EC LED Driver + * + * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net> + */ + +#include <linux/device.h> +#include <linux/leds.h> +#include <linux/led-class-multicolor.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> + +#define DRV_NAME "cros-ec-led" + +static const char * const cros_ec_led_functions[] = { + [EC_LED_ID_BATTERY_LED] = LED_FUNCTION_CHARGING, + [EC_LED_ID_POWER_LED] = LED_FUNCTION_POWER, + [EC_LED_ID_ADAPTER_LED] = "adapter", + [EC_LED_ID_LEFT_LED] = "left", + [EC_LED_ID_RIGHT_LED] = "right", + [EC_LED_ID_RECOVERY_HW_REINIT_LED] = "recovery-hw-reinit", + [EC_LED_ID_SYSRQ_DEBUG_LED] = "sysrq-debug", +}; + +static_assert(ARRAY_SIZE(cros_ec_led_functions) == EC_LED_ID_COUNT); + +static const int cros_ec_led_to_linux_id[] = { + [EC_LED_COLOR_RED] = LED_COLOR_ID_RED, + [EC_LED_COLOR_GREEN] = LED_COLOR_ID_GREEN, + [EC_LED_COLOR_BLUE] = LED_COLOR_ID_BLUE, + [EC_LED_COLOR_YELLOW] = LED_COLOR_ID_YELLOW, + [EC_LED_COLOR_WHITE] = LED_COLOR_ID_WHITE, + [EC_LED_COLOR_AMBER] = LED_COLOR_ID_AMBER, +}; + +static_assert(ARRAY_SIZE(cros_ec_led_to_linux_id) == EC_LED_COLOR_COUNT); + +static const int cros_ec_linux_to_ec_id[] = { + [LED_COLOR_ID_RED] = EC_LED_COLOR_RED, + [LED_COLOR_ID_GREEN] = EC_LED_COLOR_GREEN, + [LED_COLOR_ID_BLUE] = EC_LED_COLOR_BLUE, + [LED_COLOR_ID_YELLOW] = EC_LED_COLOR_YELLOW, + [LED_COLOR_ID_WHITE] = EC_LED_COLOR_WHITE, + [LED_COLOR_ID_AMBER] = EC_LED_COLOR_AMBER, +}; + +struct cros_ec_led_priv { + struct led_classdev_mc led_mc_cdev; + struct cros_ec_device *cros_ec; + enum ec_led_id led_id; +}; + +static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_classdev *led_cdev) +{ + return container_of(lcdev_to_mccdev(led_cdev), struct cros_ec_led_priv, led_mc_cdev); +} + +union cros_ec_led_cmd_data { + struct ec_params_led_control req; + struct ec_response_led_control resp; +} __packed; + +static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec, + union cros_ec_led_cmd_data *arg) +{ + int ret; + struct { + struct cros_ec_command msg; + union cros_ec_led_cmd_data data; + } __packed buf = { + .msg = { + .version = 1, + .command = EC_CMD_LED_CONTROL, + .insize = sizeof(arg->resp), + .outsize = sizeof(arg->req), + }, + .data.req = arg->req + }; + + ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg); + if (ret < 0) + return ret; + + arg->resp = buf.data.resp; + + return 0; +} + +static int cros_ec_led_trigger_activate(struct led_classdev *led_cdev) +{ + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); + union cros_ec_led_cmd_data arg = {}; + + arg.req.led_id = priv->led_id; + arg.req.flags = EC_LED_FLAGS_AUTO; + + return cros_ec_led_send_cmd(priv->cros_ec, &arg); +} + +static struct led_hw_trigger_type cros_ec_led_trigger_type; + +static struct led_trigger cros_ec_led_trigger = { + .name = "chromeos-auto", + .trigger_type = &cros_ec_led_trigger_type, + .activate = cros_ec_led_trigger_activate, +}; + +static int cros_ec_led_brightness_set_blocking(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + struct cros_ec_led_priv *priv = cros_ec_led_cdev_to_priv(led_cdev); + union cros_ec_led_cmd_data arg = {}; + enum ec_led_colors led_color; + struct mc_subled *subled; + size_t i; + + led_mc_calc_color_components(&priv->led_mc_cdev, brightness); + + arg.req.led_id = priv->led_id; + + for (i = 0; i < priv->led_mc_cdev.num_colors; i++) { + subled = &priv->led_mc_cdev.subled_info[i]; + led_color = cros_ec_linux_to_ec_id[subled->color_index]; + arg.req.brightness[led_color] = subled->brightness; + } + + return cros_ec_led_send_cmd(priv->cros_ec, &arg); +} + +static int cros_ec_led_count_subleds(struct device *dev, + struct ec_response_led_control *resp, + unsigned int *max_brightness) +{ + unsigned int range, common_range = 0; + int num_subleds = 0; + size_t i; + + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { + range = resp->brightness_range[i]; + + if (!range) + continue; + + num_subleds++; + + if (!common_range) + common_range = range; + + if (common_range != range) { + /* The multicolor LED API expects a uniform max_brightness */ + dev_warn(dev, "Inconsistent LED brightness values\n"); + return -EINVAL; + } + } + + if (!num_subleds) + return -EINVAL; + + *max_brightness = common_range; + return num_subleds; +} + +static const char *cros_ec_led_get_color_name(struct led_classdev_mc *led_mc_cdev) +{ + int color; + + if (led_mc_cdev->num_colors == 1) + color = led_mc_cdev->subled_info[0].color_index; + else + color = LED_COLOR_ID_MULTI; + + return led_get_color_name(color); +} + +static int cros_ec_led_probe_led(struct device *dev, struct cros_ec_device *cros_ec, + enum ec_led_id id) +{ + union cros_ec_led_cmd_data arg = {}; + struct cros_ec_led_priv *priv; + struct led_classdev *led_cdev; + struct mc_subled *subleds; + int ret, num_subleds; + size_t i, subled; + + arg.req.led_id = id; + arg.req.flags = EC_LED_FLAGS_QUERY; + ret = cros_ec_led_send_cmd(cros_ec, &arg); + /* Unknown LED, skip */ + if (ret == -EINVAL) + return 0; + if (ret == -EOPNOTSUPP) + return -ENODEV; + if (ret < 0) + return ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + num_subleds = cros_ec_led_count_subleds(dev, &arg.resp, + &priv->led_mc_cdev.led_cdev.max_brightness); + if (num_subleds < 0) + return num_subleds; + + priv->cros_ec = cros_ec; + priv->led_id = id; + + subleds = devm_kcalloc(dev, num_subleds, sizeof(*subleds), GFP_KERNEL); + if (!subleds) + return -ENOMEM; + + subled = 0; + for (i = 0; i < EC_LED_COLOR_COUNT; i++) { + if (!arg.resp.brightness_range[i]) + continue; + + subleds[subled].color_index = cros_ec_led_to_linux_id[i]; + if (subled == 0) + subleds[subled].intensity = 100; + subled++; + } + + priv->led_mc_cdev.subled_info = subleds; + priv->led_mc_cdev.num_colors = num_subleds; + + led_cdev = &priv->led_mc_cdev.led_cdev; + led_cdev->brightness_set_blocking = cros_ec_led_brightness_set_blocking; + led_cdev->trigger_type = &cros_ec_led_trigger_type; + led_cdev->default_trigger = cros_ec_led_trigger.name; + led_cdev->hw_control_trigger = cros_ec_led_trigger.name; + + led_cdev->name = devm_kasprintf(dev, GFP_KERNEL, "chromeos:%s:%s", + cros_ec_led_get_color_name(&priv->led_mc_cdev), + cros_ec_led_functions[id]); + if (!led_cdev->name) + return -ENOMEM; + + return devm_led_classdev_multicolor_register(dev, &priv->led_mc_cdev); +} + +static int cros_ec_led_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); + struct cros_ec_device *cros_ec = ec_dev->ec_dev; + int ret = 0; + size_t i; + + for (i = 0; i < EC_LED_ID_COUNT; i++) { + ret = cros_ec_led_probe_led(dev, cros_ec, i); + if (ret) + break; + } + + return ret; +} + +static const struct platform_device_id cros_ec_led_id[] = { + { DRV_NAME, 0 }, + {} +}; + +static struct platform_driver cros_ec_led_driver = { + .driver.name = DRV_NAME, + .probe = cros_ec_led_probe, + .id_table = cros_ec_led_id, +}; + +static int __init cros_ec_led_init(void) +{ + int ret; + + ret = led_trigger_register(&cros_ec_led_trigger); + if (ret) + return ret; + + ret = platform_driver_register(&cros_ec_led_driver); + if (ret) + led_trigger_unregister(&cros_ec_led_trigger); + + return ret; +}; +module_init(cros_ec_led_init); + +static void __exit cros_ec_led_exit(void) +{ + platform_driver_unregister(&cros_ec_led_driver); + led_trigger_unregister(&cros_ec_led_trigger); +}; +module_exit(cros_ec_led_exit); + +MODULE_DEVICE_TABLE(platform, cros_ec_led_id); +MODULE_DESCRIPTION("ChromeOS EC LED Driver"); +MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net"); +MODULE_LICENSE("GPL");
The ChromeOS Embedded Controller exposes an LED control command. Expose its functionality through the leds subsystem. The LEDs are exposed as multicolor devices. A hardware trigger, which is active by default, is provided to let the EC itself take over control over the LED. The driver is designed to be probed via the cros_ec mfd device. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> --- MAINTAINERS | 5 + drivers/leds/Kconfig | 15 +++ drivers/leds/Makefile | 1 + drivers/leds/leds-cros_ec.c | 299 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 320 insertions(+)