iio: proximity: vl53l0x-i2c: claim direct mode for raw readsgrafted

vl53l0x_read_raw() starts a single-shot ranging measurement and reads
back the result. Once the triggered buffer is enabled the sensor runs in
continuous mode and its data-ready interrupt is routed to the trigger,
so a concurrent in_distance_raw read disturbs the streaming setup and
never gets its completion, returning -ETIMEDOUT.

The original submission claimed direct mode here, but it was dropped
during review because the driver had no buffer support at the time [1].
Continuous (buffered) mode was later added without restoring the
claim [2], reintroducing the conflict.

Reject direct reads while buffered capture is active by claiming direct
mode around the measurement, as the vl53l1x sibling already does.

Fixes: 762186c6e7b1 ("iio: proximity: vl53l0x-i2c: Added continuous mode support")
Link: https://lore.kernel.org/linux-iio/20180911160300.GA9212@himanshu-Vostro-3559/ [1]
Link: https://lore.kernel.org/linux-iio/20240909101508.263085-3-abhashkumarjha123@gmail.com/ [2]
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/include/uapi/fwctl/pds.h b/include/uapi/fwctl/pds.h
new file mode 100644
index 000000000..66be32411
--- /dev/null
+++ b/include/uapi/fwctl/pds.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright(c) Advanced Micro Devices, Inc */
+
+/*
+ * fwctl interface info for pds_fwctl
+ */
+
+#ifndef _UAPI_FWCTL_PDS_H_
+#define _UAPI_FWCTL_PDS_H_
+
+#include <linux/types.h>
+
+/**
+ * struct fwctl_info_pds
+ * @uctx_caps:  bitmap of firmware capabilities
+ *
+ * Return basic information about the FW interface available.
+ */
+struct fwctl_info_pds {
+	__u32 uctx_caps;
+};
+
+/**
+ * enum pds_fwctl_capabilities
+ * @PDS_FWCTL_QUERY_CAP: firmware can be queried for information
+ * @PDS_FWCTL_SEND_CAP:  firmware can be sent commands
+ */
+enum pds_fwctl_capabilities {
+	PDS_FWCTL_QUERY_CAP = 0,
+	PDS_FWCTL_SEND_CAP,
+};
+
+/**
+ * struct fwctl_rpc_pds
+ * @in.op:       requested operation code
+ * @in.ep:       firmware endpoint to operate on
+ * @in.rsvd:     reserved
+ * @in.len:      length of payload data
+ * @in.payload:  address of payload buffer
+ * @in:          rpc in parameters
+ * @out.retval:  operation result value
+ * @out.rsvd:    reserved
+ * @out.len:     length of result data buffer
+ * @out.payload: address of payload data buffer
+ * @out:         rpc out parameters
+ */
+struct fwctl_rpc_pds {
+	struct {
+		__u32 op;
+		__u32 ep;
+		__u32 rsvd;
+		__u32 len;
+		__aligned_u64 payload;
+	} in;
+	struct {
+		__u32 retval;
+		__u32 rsvd[2];
+		__u32 len;
+		__aligned_u64 payload;
+	} out;
+};
+#endif /* _UAPI_FWCTL_PDS_H_ */