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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/media/rc/ir-rc5-decoder.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/media/rc/ir-rc5-decoder.c')
-rw-r--r--drivers/media/rc/ir-rc5-decoder.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-rc5-decoder.c b/drivers/media/rc/ir-rc5-decoder.c
new file mode 100644
index 000000000..82d7f6ad2
--- /dev/null
+++ b/drivers/media/rc/ir-rc5-decoder.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: GPL-2.0
+// ir-rc5-decoder.c - decoder for RC5(x) and StreamZap protocols
+//
+// Copyright (C) 2010 by Mauro Carvalho Chehab
+// Copyright (C) 2010 by Jarod Wilson <jarod@redhat.com>
+
+/*
+ * This decoder handles the 14 bit RC5 protocol, 15 bit "StreamZap" protocol
+ * and 20 bit RC5x protocol.
+ */
+
+#include "rc-core-priv.h"
+#include <linux/module.h>
+
+#define RC5_NBITS 14
+#define RC5_SZ_NBITS 15
+#define RC5X_NBITS 20
+#define CHECK_RC5X_NBITS 8
+#define RC5_UNIT 889 /* us */
+#define RC5_BIT_START (1 * RC5_UNIT)
+#define RC5_BIT_END (1 * RC5_UNIT)
+#define RC5X_SPACE (4 * RC5_UNIT)
+#define RC5_TRAILER (6 * RC5_UNIT) /* In reality, approx 100 */
+
+enum rc5_state {
+ STATE_INACTIVE,
+ STATE_BIT_START,
+ STATE_BIT_END,
+ STATE_CHECK_RC5X,
+ STATE_FINISHED,
+};
+
+/**
+ * ir_rc5_decode() - Decode one RC-5 pulse or space
+ * @dev: the struct rc_dev descriptor of the device
+ * @ev: the struct ir_raw_event descriptor of the pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
+ */
+static int ir_rc5_decode(struct rc_dev *dev, struct ir_raw_event ev)
+{
+ struct rc5_dec *data = &dev->raw->rc5;
+ u8 toggle;
+ u32 scancode;
+ enum rc_proto protocol;
+
+ if (!is_timing_event(ev)) {
+ if (ev.overflow)
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
+
+ if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
+ goto out;
+
+again:
+ dev_dbg(&dev->dev, "RC5(x/sz) decode started at state %i (%uus %s)\n",
+ data->state, ev.duration, TO_STR(ev.pulse));
+
+ if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
+ return 0;
+
+ switch (data->state) {
+
+ case STATE_INACTIVE:
+ if (!ev.pulse)
+ break;
+
+ data->state = STATE_BIT_START;
+ data->count = 1;
+ decrease_duration(&ev, RC5_BIT_START);
+ goto again;
+
+ case STATE_BIT_START:
+ if (!ev.pulse && geq_margin(ev.duration, RC5_TRAILER, RC5_UNIT / 2)) {
+ data->state = STATE_FINISHED;
+ goto again;
+ }
+
+ if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2))
+ break;
+
+ data->bits <<= 1;
+ if (!ev.pulse)
+ data->bits |= 1;
+ data->count++;
+ data->state = STATE_BIT_END;
+ return 0;
+
+ case STATE_BIT_END:
+ if (data->count == CHECK_RC5X_NBITS)
+ data->state = STATE_CHECK_RC5X;
+ else
+ data->state = STATE_BIT_START;
+
+ decrease_duration(&ev, RC5_BIT_END);
+ goto again;
+
+ case STATE_CHECK_RC5X:
+ if (!ev.pulse && geq_margin(ev.duration, RC5X_SPACE, RC5_UNIT / 2)) {
+ data->is_rc5x = true;
+ decrease_duration(&ev, RC5X_SPACE);
+ } else
+ data->is_rc5x = false;
+ data->state = STATE_BIT_START;
+ goto again;
+
+ case STATE_FINISHED:
+ if (ev.pulse)
+ break;
+
+ if (data->is_rc5x && data->count == RC5X_NBITS) {
+ /* RC5X */
+ u8 xdata, command, system;
+ if (!(dev->enabled_protocols & RC_PROTO_BIT_RC5X_20)) {
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
+ xdata = (data->bits & 0x0003F) >> 0;
+ command = (data->bits & 0x00FC0) >> 6;
+ system = (data->bits & 0x1F000) >> 12;
+ toggle = (data->bits & 0x20000) ? 1 : 0;
+ command += (data->bits & 0x40000) ? 0 : 0x40;
+ scancode = system << 16 | command << 8 | xdata;
+ protocol = RC_PROTO_RC5X_20;
+
+ } else if (!data->is_rc5x && data->count == RC5_NBITS) {
+ /* RC5 */
+ u8 command, system;
+ if (!(dev->enabled_protocols & RC_PROTO_BIT_RC5)) {
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
+ command = (data->bits & 0x0003F) >> 0;
+ system = (data->bits & 0x007C0) >> 6;
+ toggle = (data->bits & 0x00800) ? 1 : 0;
+ command += (data->bits & 0x01000) ? 0 : 0x40;
+ scancode = system << 8 | command;
+ protocol = RC_PROTO_RC5;
+
+ } else if (!data->is_rc5x && data->count == RC5_SZ_NBITS) {
+ /* RC5 StreamZap */
+ u8 command, system;
+ if (!(dev->enabled_protocols & RC_PROTO_BIT_RC5_SZ)) {
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
+ command = (data->bits & 0x0003F) >> 0;
+ system = (data->bits & 0x02FC0) >> 6;
+ toggle = (data->bits & 0x01000) ? 1 : 0;
+ scancode = system << 6 | command;
+ protocol = RC_PROTO_RC5_SZ;
+
+ } else
+ break;
+
+ dev_dbg(&dev->dev, "RC5(x/sz) scancode 0x%06x (p: %u, t: %u)\n",
+ scancode, protocol, toggle);
+
+ rc_keydown(dev, protocol, scancode, toggle);
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
+
+out:
+ dev_dbg(&dev->dev, "RC5(x/sz) decode failed at state %i count %d (%uus %s)\n",
+ data->state, data->count, ev.duration, TO_STR(ev.pulse));
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+}
+
+static const struct ir_raw_timings_manchester ir_rc5_timings = {
+ .leader_pulse = RC5_UNIT,
+ .clock = RC5_UNIT,
+ .trailer_space = RC5_UNIT * 10,
+};
+
+static const struct ir_raw_timings_manchester ir_rc5x_timings[2] = {
+ {
+ .leader_pulse = RC5_UNIT,
+ .clock = RC5_UNIT,
+ .trailer_space = RC5X_SPACE,
+ },
+ {
+ .clock = RC5_UNIT,
+ .trailer_space = RC5_UNIT * 10,
+ },
+};
+
+static const struct ir_raw_timings_manchester ir_rc5_sz_timings = {
+ .leader_pulse = RC5_UNIT,
+ .clock = RC5_UNIT,
+ .trailer_space = RC5_UNIT * 10,
+};
+
+/**
+ * ir_rc5_encode() - Encode a scancode as a stream of raw events
+ *
+ * @protocol: protocol variant to encode
+ * @scancode: scancode to encode
+ * @events: array of raw ir events to write into
+ * @max: maximum size of @events
+ *
+ * Returns: The number of events written.
+ * -ENOBUFS if there isn't enough space in the array to fit the
+ * encoding. In this case all @max events will have been written.
+ * -EINVAL if the scancode is ambiguous or invalid.
+ */
+static int ir_rc5_encode(enum rc_proto protocol, u32 scancode,
+ struct ir_raw_event *events, unsigned int max)
+{
+ int ret;
+ struct ir_raw_event *e = events;
+ unsigned int data, xdata, command, commandx, system, pre_space_data;
+
+ /* Detect protocol and convert scancode to raw data */
+ if (protocol == RC_PROTO_RC5) {
+ /* decode scancode */
+ command = (scancode & 0x003f) >> 0;
+ commandx = (scancode & 0x0040) >> 6;
+ system = (scancode & 0x1f00) >> 8;
+ /* encode data */
+ data = !commandx << 12 | system << 6 | command;
+
+ /* First bit is encoded by leader_pulse */
+ ret = ir_raw_gen_manchester(&e, max, &ir_rc5_timings,
+ RC5_NBITS - 1, data);
+ if (ret < 0)
+ return ret;
+ } else if (protocol == RC_PROTO_RC5X_20) {
+ /* decode scancode */
+ xdata = (scancode & 0x00003f) >> 0;
+ command = (scancode & 0x003f00) >> 8;
+ commandx = !(scancode & 0x004000);
+ system = (scancode & 0x1f0000) >> 16;
+
+ /* encode data */
+ data = commandx << 18 | system << 12 | command << 6 | xdata;
+
+ /* First bit is encoded by leader_pulse */
+ pre_space_data = data >> (RC5X_NBITS - CHECK_RC5X_NBITS);
+ ret = ir_raw_gen_manchester(&e, max, &ir_rc5x_timings[0],
+ CHECK_RC5X_NBITS - 1,
+ pre_space_data);
+ if (ret < 0)
+ return ret;
+ ret = ir_raw_gen_manchester(&e, max - (e - events),
+ &ir_rc5x_timings[1],
+ RC5X_NBITS - CHECK_RC5X_NBITS,
+ data);
+ if (ret < 0)
+ return ret;
+ } else if (protocol == RC_PROTO_RC5_SZ) {
+ /* RC5-SZ scancode is raw enough for Manchester as it is */
+ /* First bit is encoded by leader_pulse */
+ ret = ir_raw_gen_manchester(&e, max, &ir_rc5_sz_timings,
+ RC5_SZ_NBITS - 1,
+ scancode & 0x2fff);
+ if (ret < 0)
+ return ret;
+ } else {
+ return -EINVAL;
+ }
+
+ return e - events;
+}
+
+static struct ir_raw_handler rc5_handler = {
+ .protocols = RC_PROTO_BIT_RC5 | RC_PROTO_BIT_RC5X_20 |
+ RC_PROTO_BIT_RC5_SZ,
+ .decode = ir_rc5_decode,
+ .encode = ir_rc5_encode,
+ .carrier = 36000,
+ .min_timeout = RC5_TRAILER,
+};
+
+static int __init ir_rc5_decode_init(void)
+{
+ ir_raw_handler_register(&rc5_handler);
+
+ printk(KERN_INFO "IR RC5(x/sz) protocol handler initialized\n");
+ return 0;
+}
+
+static void __exit ir_rc5_decode_exit(void)
+{
+ ir_raw_handler_unregister(&rc5_handler);
+}
+
+module_init(ir_rc5_decode_init);
+module_exit(ir_rc5_decode_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Mauro Carvalho Chehab and Jarod Wilson");
+MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
+MODULE_DESCRIPTION("RC5(x/sz) IR protocol decoder");