summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorAdrian Hunter <adrian.hunter@intel.com>2026-08-07 17:56:34 +0300
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2026-08-08 15:04:20 +0200
commit60ff731f06909f9b54af27d70f00a41bd84c6246 (patch)
tree8d853254f00adcc35369f9733614d17c02814bd8 /drivers
parentff2b20f8f1ff9680ca1fce315e1d5eddd687266d (diff)
downloadlinux-60ff731f06909f9b54af27d70f00a41bd84c6246.tar.gz
linux-60ff731f06909f9b54af27d70f00a41bd84c6246.zip
i3c: master: Add helper to query bus wakeup requirements
Add i3c_master_has_wakeup_enabled_devs(), which iterates over the devices on an I3C bus and reports whether any of them are enabled for system wakeup and have IBI enabled. Controller drivers can use this helper to determine whether wakeup support must remain available while the system is suspended. Acked-by : Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260807145638.168865-11-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i3c/master.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 6c5341491944..afcd7a21a3e6 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2148,6 +2148,41 @@ static void i3c_master_reg_work_fn(struct work_struct *work)
}
/**
+ * i3c_master_has_wakeup_enabled_devs() - check if any device can wake the system
+ * @master: I3C master controller
+ *
+ * Iterate over devices on the bus and return true if any device has
+ * system wakeup enabled and IBI enabled.
+ *
+ * Whether a device is enabled for system wakeup is user space policy,
+ * settable at any time through the device's power/wakeup sysfs attribute,
+ * so the answer is only stable once user space is frozen. Call this from
+ * a system suspend callback.
+ *
+ * Return: true if any device may wake the system via IBI, false otherwise.
+ */
+bool i3c_master_has_wakeup_enabled_devs(struct i3c_master_controller *master)
+{
+ struct i3c_dev_desc *desc;
+ bool wakeup = false;
+
+ i3c_bus_normaluse_lock(&master->bus);
+ i3c_bus_for_each_i3cdev(&master->bus, desc) {
+ if (!desc->dev || desc == master->this || !device_may_wakeup(&desc->dev->dev))
+ continue;
+ guard(mutex)(&desc->ibi_lock);
+ if (desc->ibi && desc->ibi->enabled) {
+ wakeup = true;
+ break;
+ }
+ }
+ i3c_bus_normaluse_unlock(&master->bus);
+
+ return wakeup;
+}
+EXPORT_SYMBOL_GPL(i3c_master_has_wakeup_enabled_devs);
+
+/**
* i3c_master_dma_map_single() - Map buffer for single DMA transfer
* @dev: device object of a device doing DMA
* @buf: destination/source buffer for DMA