diff options
| author | Gwendal Grignou <gwendal@chromium.org> | 2026-01-30 00:13:50 -0800 |
|---|---|---|
| committer | Tzung-Bi Shih <tzungbi@kernel.org> | 2026-01-30 08:29:52 +0000 |
| commit | 2d8251d98ce0be96d79aec708aa70cab2b4f6f17 (patch) | |
| tree | 136ea0ac9ec176cccc2b48b5d133e3a1524785d3 /drivers | |
| parent | ec0dd36dbf8b0b209e63d0cd795451fa2203c736 (diff) | |
platform/chrome: lightbar: Report number of segments
Add attribue `num_segments` to return the number of exposed LED segments
in the lightbar. It can be smaller than the number of physical leds in
the lightbar.
Test: Check the attribute is present and returns a value when read.
Signed-off-by: Gwendal Grignou <gwendal@google.com>
Link: https://lore.kernel.org/r/20260130081351.487517-1-gwendal@google.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/platform/chrome/cros_ec_lightbar.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c index 3702baff5d4f..8ee761450394 100644 --- a/drivers/platform/chrome/cros_ec_lightbar.c +++ b/drivers/platform/chrome/cros_ec_lightbar.c @@ -180,6 +180,47 @@ static ssize_t version_show(struct device *dev, return sysfs_emit(buf, "%d %d\n", version, flags); } +static ssize_t num_segments_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ec_params_lightbar *param; + struct ec_response_lightbar *resp; + struct cros_ec_command *msg; + struct cros_ec_dev *ec = to_cros_ec_dev(dev); + uint32_t num = 0; + int ret; + + ret = lb_throttle(); + if (ret) + return ret; + + msg = alloc_lightbar_cmd_msg(ec); + if (!msg) + return -ENOMEM; + + param = (struct ec_params_lightbar *)msg->data; + param->cmd = LIGHTBAR_CMD_GET_PARAMS_V3; + msg->outsize = sizeof(param->cmd); + msg->insize = sizeof(resp->get_params_v3); + ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg); + if (ret < 0 && ret != -EINVAL) + goto exit; + + if (msg->result == EC_RES_SUCCESS) { + resp = (struct ec_response_lightbar *)msg->data; + num = resp->get_params_v3.reported_led_num; + } + + /* + * Anything else (ie, EC_RES_INVALID_COMMAND) - no direct control over + * LEDs, return that no leds are supported. + */ + ret = sysfs_emit(buf, "%u\n", num); +exit: + kfree(msg); + return ret; +} + static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) @@ -512,6 +553,7 @@ static ssize_t userspace_control_store(struct device *dev, /* Module initialization */ static DEVICE_ATTR_RW(interval_msec); +static DEVICE_ATTR_RO(num_segments); static DEVICE_ATTR_RO(version); static DEVICE_ATTR_WO(brightness); static DEVICE_ATTR_WO(led_rgb); @@ -521,6 +563,7 @@ static DEVICE_ATTR_RW(userspace_control); static struct attribute *__lb_cmds_attrs[] = { &dev_attr_interval_msec.attr, + &dev_attr_num_segments.attr, &dev_attr_version.attr, &dev_attr_brightness.attr, &dev_attr_led_rgb.attr, |