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authorJakub Kicinski <kuba@kernel.org>2024-02-29 14:17:54 -0800
committerJakub Kicinski <kuba@kernel.org>2024-02-29 14:24:56 -0800
commit65f5dd4f02a89df429b8212b4c2f3ada6c4f3fc1 (patch)
tree4c201974fa7e35e99c530ab3d0429dc894d64cf3 /drivers/platform/x86/serdev_helpers.h
parent489645d3f1332f65a9337cb31c0ee12a1259a484 (diff)
parent87adedeba51a822533649b143232418b9e26d08b (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. Conflicts: net/mptcp/protocol.c adf1bb78dab5 ("mptcp: fix snd_wnd initialization for passive socket") 9426ce476a70 ("mptcp: annotate lockless access for RX path fields") https://lore.kernel.org/all/20240228103048.19255709@canb.auug.org.au/ Adjacent changes: drivers/dpll/dpll_core.c 0d60d8df6f49 ("dpll: rely on rcu for netdev_dpll_pin()") e7f8df0e81bf ("dpll: move xa_erase() call in to match dpll_pin_alloc() error path order") drivers/net/veth.c 1ce7d306ea63 ("veth: try harder when allocating queue memory") 0bef512012b1 ("net: add netdev_lockdep_set_classes() to virtual drivers") drivers/net/wireless/intel/iwlwifi/mvm/d3.c 8c9bef26e98b ("wifi: iwlwifi: mvm: d3: implement suspend with MLO") 78f65fbf421a ("wifi: iwlwifi: mvm: ensure offloading TID queue exists") net/wireless/nl80211.c f78c1375339a ("wifi: nl80211: reject iftype change with mesh ID change") 414532d8aa89 ("wifi: cfg80211: use IEEE80211_MAX_MESH_ID_LEN appropriately") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/platform/x86/serdev_helpers.h')
-rw-r--r--drivers/platform/x86/serdev_helpers.h80
1 files changed, 80 insertions, 0 deletions
diff --git a/drivers/platform/x86/serdev_helpers.h b/drivers/platform/x86/serdev_helpers.h
new file mode 100644
index 000000000000..bcf3a0c356ea
--- /dev/null
+++ b/drivers/platform/x86/serdev_helpers.h
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * In some cases UART attached devices which require an in kernel driver,
+ * e.g. UART attached Bluetooth HCIs are described in the ACPI tables
+ * by an ACPI device with a broken or missing UartSerialBusV2() resource.
+ *
+ * This causes the kernel to create a /dev/ttyS# char-device for the UART
+ * instead of creating an in kernel serdev-controller + serdev-device pair
+ * for the in kernel driver.
+ *
+ * The quirk handling in acpi_quirk_skip_serdev_enumeration() makes the kernel
+ * create a serdev-controller device for these UARTs instead of a /dev/ttyS#.
+ *
+ * Instantiating the actual serdev-device to bind to is up to pdx86 code,
+ * this header provides a helper for getting the serdev-controller device.
+ */
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/printk.h>
+#include <linux/sprintf.h>
+#include <linux/string.h>
+
+static inline struct device *
+get_serdev_controller(const char *serial_ctrl_hid,
+ const char *serial_ctrl_uid,
+ int serial_ctrl_port,
+ const char *serdev_ctrl_name)
+{
+ struct device *ctrl_dev, *child;
+ struct acpi_device *ctrl_adev;
+ char name[32];
+ int i;
+
+ ctrl_adev = acpi_dev_get_first_match_dev(serial_ctrl_hid, serial_ctrl_uid, -1);
+ if (!ctrl_adev) {
+ pr_err("error could not get %s/%s serial-ctrl adev\n",
+ serial_ctrl_hid, serial_ctrl_uid);
+ return ERR_PTR(-ENODEV);
+ }
+
+ /* get_first_physical_node() returns a weak ref */
+ ctrl_dev = get_device(acpi_get_first_physical_node(ctrl_adev));
+ if (!ctrl_dev) {
+ pr_err("error could not get %s/%s serial-ctrl physical node\n",
+ serial_ctrl_hid, serial_ctrl_uid);
+ ctrl_dev = ERR_PTR(-ENODEV);
+ goto put_ctrl_adev;
+ }
+
+ /* Walk host -> uart-ctrl -> port -> serdev-ctrl */
+ for (i = 0; i < 3; i++) {
+ switch (i) {
+ case 0:
+ snprintf(name, sizeof(name), "%s:0", dev_name(ctrl_dev));
+ break;
+ case 1:
+ snprintf(name, sizeof(name), "%s.%d",
+ dev_name(ctrl_dev), serial_ctrl_port);
+ break;
+ case 2:
+ strscpy(name, serdev_ctrl_name, sizeof(name));
+ break;
+ }
+
+ child = device_find_child_by_name(ctrl_dev, name);
+ put_device(ctrl_dev);
+ if (!child) {
+ pr_err("error could not find '%s' device\n", name);
+ ctrl_dev = ERR_PTR(-ENODEV);
+ goto put_ctrl_adev;
+ }
+
+ ctrl_dev = child;
+ }
+
+put_ctrl_adev:
+ acpi_dev_put(ctrl_adev);
+ return ctrl_dev;
+}