kernel/linux.git/include/linux/iio, branch v6.12.80

iio: core: add separate lockdep class for info_exist_lock

2026-01-30T09:28:48+00:00

[ Upstream commit 9910159f06590c17df4fbddedaabb4c0201cc4cb ] When one iio device is a consumer of another, it is possible that the ->info_exist_lock of both ends up being taken when reading the value of the consumer device. Since they currently belong to the same lockdep class (being initialized in a single location with mutex_init()), that results in a lockdep warning CPU0 ---- lock(&iio_dev_opaque->info_exist_lock); lock(&iio_dev_opaque->info_exist_lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by sensors/414: #0: c31fd6dc (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x44/0x4e4 #1: c4f5a1c4 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x1c/0xac #2: c2827548 (kn->active#34){.+.+}-{0:0}, at: kernfs_seq_start+0x30/0xac #3: c1dd2b68 (&iio_dev_opaque->info_exist_lock){+.+.}-{3:3}, at: iio_read_channel_processed_scale+0x24/0xd8 stack backtrace: CPU: 0 UID: 0 PID: 414 Comm: sensors Not tainted 6.17.11 #5 NONE Hardware name: Generic AM33XX (Flattened Device Tree) Call trace: unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x44/0x60 dump_stack_lvl from print_deadlock_bug+0x2b8/0x334 print_deadlock_bug from __lock_acquire+0x13a4/0x2ab0 __lock_acquire from lock_acquire+0xd0/0x2c0 lock_acquire from __mutex_lock+0xa0/0xe8c __mutex_lock from mutex_lock_nested+0x1c/0x24 mutex_lock_nested from iio_read_channel_raw+0x20/0x6c iio_read_channel_raw from rescale_read_raw+0x128/0x1c4 rescale_read_raw from iio_channel_read+0xe4/0xf4 iio_channel_read from iio_read_channel_processed_scale+0x6c/0xd8 iio_read_channel_processed_scale from iio_hwmon_read_val+0x68/0xbc iio_hwmon_read_val from dev_attr_show+0x18/0x48 dev_attr_show from sysfs_kf_seq_show+0x80/0x110 sysfs_kf_seq_show from seq_read_iter+0xdc/0x4e4 seq_read_iter from vfs_read+0x238/0x2e4 vfs_read from ksys_read+0x6c/0xec ksys_read from ret_fast_syscall+0x0/0x1c Just as the mlock_key already has its own lockdep class, add a lock_class_key for the info_exist mutex. Note that this has in theory been a problem since before IIO first left staging, but it only occurs when a chain of consumers is in use and that is not often done. Fixes: ac917a81117c ("staging:iio:core set the iio_dev.info pointer to null on unregister under lock.") Signed-off-by: Rasmus Villemoes Reviewed-by: Peter Rosin Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

iio: buffer: support getting dma channel from the buffer

2025-12-06T21:24:57+00:00

commit a514bb109eada64f798f1c86c17182229cc20fe7 upstream. Add a new buffer accessor .get_dma_dev() in order to get the struct device responsible for actually providing the dma channel. We cannot assume that we can use the parent of the IIO device for mapping the DMA buffer. This becomes important on systems (like the Xilinx/AMD zynqMP Ultrascale) where memory (or part of it) is mapped above the 32 bit range. On such systems and given that a device by default has a dma mask of 32 bits we would then need to rely on bounce buffers (to swiotlb) for mapping memory above the dma mask limit. In the process, add an iio_buffer_get_dma_dev() helper function to get the proper DMA device. Cc: stable@vger.kernel.org Reviewed-by: David Lechner Signed-off-by: Nuno Sá Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman

iio: buffer-dma: support getting the DMA channel

2025-12-06T21:24:57+00:00

commit f9c198c3ccaf90a1a265fb2ffa8d4b093c3b0784 upstream. Implement the .get_dma_dev() callback for DMA buffers by returning the device that owns the DMA channel. This allows the core DMABUF infrastructure to properly map DMA buffers using the correct device, avoiding the need for bounce buffers on systems where memory is mapped above the 32-bit range. The function returns the DMA queue's device, which is the actual device responsible for DMA operations in buffer-dma implementations. Cc: stable@vger.kernel.org Reviewed-by: David Lechner Signed-off-by: Nuno Sá Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman

iio: frequency: adf4350: Fix ADF4350_REG3_12BIT_CLKDIV_MODE

2025-10-19T14:33:34+00:00

commit 1d8fdabe19267338f29b58f968499e5b55e6a3b6 upstream. The clk div bits (2 bits wide) do not start in bit 16 but in bit 15. Fix it accordingly. Fixes: e31166f0fd48 ("iio: frequency: New driver for Analog Devices ADF4350/ADF4351 Wideband Synthesizers") Signed-off-by: Michael Hennerich Signed-off-by: Nuno Sá Link: https://patch.msgid.link/20250829-adf4350-fix-v2-2-0bf543ba797d@analog.com Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman

iio: trigger: allow devices to suspend/resume theirs associated trigger

2024-08-10T10:19:36+00:00

When a machine enters a sleep state while a trigger is associated to an iio device that trigger is not resumed after exiting the sleep state: provide iio device drivers a way to suspend and resume the associated trigger to solve the aforementioned bug. Each iio driver supporting external triggers is expected to call iio_device_suspend_triggering before suspending, and iio_device_resume_triggering upon resuming. Signed-off-by: Denis Benato Link: https://patch.msgid.link/20240807185619.7261-2-benato.denis96@gmail.com Signed-off-by: Jonathan Cameron

iio: add child nodes support in iio backend framework

2024-08-10T10:17:34+00:00

Add an API to support IIO generic channels binding: http://devicetree.org/schemas/iio/adc/adc.yaml# This new API is needed, as generic channel DT node isn't populated as a device. Add devm_iio_backend_fwnode_get() to allow an IIO device backend consumer to reference backend phandles in its child nodes. Signed-off-by: Olivier Moysan Reviewed-by: Nuno Sa Link: https://patch.msgid.link/20240730084640.1307938-4-olivier.moysan@foss.st.com Signed-off-by: Jonathan Cameron

iio: add enable and disable services to iio backend framework

2024-08-10T10:17:34+00:00

Add iio_backend_disable() and iio_backend_enable() APIs to allow IIO backend consumer to request backend disabling and enabling. Signed-off-by: Olivier Moysan Reviewed-by: Nuno Sa Link: https://patch.msgid.link/20240730084640.1307938-3-olivier.moysan@foss.st.com Signed-off-by: Jonathan Cameron

iio: add read scale and offset services to iio backend framework

2024-08-10T10:17:34+00:00

Add iio_backend_read_scale() and iio_backend_read_offset() services to read channel scale and offset from an IIO backbend device. Also add a read_raw callback which replicates the read_raw callback of the IIO framework, and is intended to request miscellaneous channel attributes from the backend device. Both scale and offset helpers use this callback. Signed-off-by: Olivier Moysan Reviewed-by: Nuno Sa Link: https://patch.msgid.link/20240730084640.1307938-2-olivier.moysan@foss.st.com Signed-off-by: Jonathan Cameron

iio: backend: add a modified prbs23 support

2024-08-03T13:36:45+00:00

Support ADI specific prb23 sequence that can be used both for calibrating or debugging digital interfaces. Signed-off-by: Nuno Sa Link: https://patch.msgid.link/20240802-dev-iio-backend-add-debugfs-v2-3-4cb62852f0d0@analog.com Signed-off-by: Jonathan Cameron

iio: backend: add debugFs interface

2024-08-03T13:36:45+00:00

This adds a basic debugfs interface for backends. Two new ops are being added: * debugfs_reg_access: Analogous to the core IIO one but for backend devices. * debugfs_print_chan_status: One useful usecase for this one is for testing test tones in a digital interface and "ask" the backend to dump more details on why a test tone might have errors. Signed-off-by: Nuno Sa Link: https://patch.msgid.link/20240802-dev-iio-backend-add-debugfs-v2-2-4cb62852f0d0@analog.com Signed-off-by: Jonathan Cameron