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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/media/rc/ir-imon-decoder.c | |
| download | linux-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-imon-decoder.c')
| -rw-r--r-- | drivers/media/rc/ir-imon-decoder.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-imon-decoder.c b/drivers/media/rc/ir-imon-decoder.c new file mode 100644 index 000000000..dc68f64e7 --- /dev/null +++ b/drivers/media/rc/ir-imon-decoder.c @@ -0,0 +1,267 @@ +// SPDX-License-Identifier: GPL-2.0+ +// ir-imon-decoder.c - handle iMon protocol +// +// Copyright (C) 2018 by Sean Young <sean@mess.org> + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include "rc-core-priv.h" + +#define IMON_UNIT 416 /* us */ +#define IMON_BITS 30 +#define IMON_CHKBITS (BIT(30) | BIT(25) | BIT(24) | BIT(22) | \ + BIT(21) | BIT(20) | BIT(19) | BIT(18) | \ + BIT(17) | BIT(16) | BIT(14) | BIT(13) | \ + BIT(12) | BIT(11) | BIT(10) | BIT(9)) + +/* + * This protocol has 30 bits. The format is one IMON_UNIT header pulse, + * followed by 30 bits. Each bit is one IMON_UNIT check field, and then + * one IMON_UNIT field with the actual bit (1=space, 0=pulse). + * The check field is always space for some bits, for others it is pulse if + * both the preceding and current bit are zero, else space. IMON_CHKBITS + * defines which bits are of type check. + * + * There is no way to distinguish an incomplete message from one where + * the lower bits are all set, iow. the last pulse is for the lowest + * bit which is 0. + */ +enum imon_state { + STATE_INACTIVE, + STATE_BIT_CHK, + STATE_BIT_START, + STATE_FINISHED, + STATE_ERROR, +}; + +static void ir_imon_decode_scancode(struct rc_dev *dev) +{ + struct imon_dec *imon = &dev->raw->imon; + + /* Keyboard/Mouse toggle */ + if (imon->bits == 0x299115b7) + imon->stick_keyboard = !imon->stick_keyboard; + + if ((imon->bits & 0xfc0000ff) == 0x680000b7) { + int rel_x, rel_y; + u8 buf; + + buf = imon->bits >> 16; + rel_x = (buf & 0x08) | (buf & 0x10) >> 2 | + (buf & 0x20) >> 4 | (buf & 0x40) >> 6; + if (imon->bits & 0x02000000) + rel_x |= ~0x0f; + buf = imon->bits >> 8; + rel_y = (buf & 0x08) | (buf & 0x10) >> 2 | + (buf & 0x20) >> 4 | (buf & 0x40) >> 6; + if (imon->bits & 0x01000000) + rel_y |= ~0x0f; + + if (rel_x && rel_y && imon->stick_keyboard) { + if (abs(rel_y) > abs(rel_x)) + imon->bits = rel_y > 0 ? + 0x289515b7 : /* KEY_DOWN */ + 0x2aa515b7; /* KEY_UP */ + else + imon->bits = rel_x > 0 ? + 0x2ba515b7 : /* KEY_RIGHT */ + 0x29a515b7; /* KEY_LEFT */ + } + + if (!imon->stick_keyboard) { + input_report_rel(dev->input_dev, REL_X, rel_x); + input_report_rel(dev->input_dev, REL_Y, rel_y); + + input_report_key(dev->input_dev, BTN_LEFT, + (imon->bits & 0x00010000) != 0); + input_report_key(dev->input_dev, BTN_RIGHT, + (imon->bits & 0x00040000) != 0); + } + } + + rc_keydown(dev, RC_PROTO_IMON, imon->bits, 0); +} + +/** + * ir_imon_decode() - Decode one iMON 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_imon_decode(struct rc_dev *dev, struct ir_raw_event ev) +{ + struct imon_dec *data = &dev->raw->imon; + + if (!is_timing_event(ev)) { + if (ev.overflow) + data->state = STATE_INACTIVE; + return 0; + } + + dev_dbg(&dev->dev, + "iMON decode started at state %d bitno %d (%uus %s)\n", + data->state, data->count, ev.duration, TO_STR(ev.pulse)); + + /* + * Since iMON protocol is a series of bits, if at any point + * we encounter an error, make sure that any remaining bits + * aren't parsed as a scancode made up of less bits. + * + * Note that if the stick is held, then the remote repeats + * the scancode with about 12ms between them. So, make sure + * we have at least 10ms of space after an error. That way, + * we're at a new scancode. + */ + if (data->state == STATE_ERROR) { + if (!ev.pulse && ev.duration > MS_TO_US(10)) + data->state = STATE_INACTIVE; + return 0; + } + + for (;;) { + if (!geq_margin(ev.duration, IMON_UNIT, IMON_UNIT / 2)) + return 0; + + decrease_duration(&ev, IMON_UNIT); + + switch (data->state) { + case STATE_INACTIVE: + if (ev.pulse) { + data->state = STATE_BIT_CHK; + data->bits = 0; + data->count = IMON_BITS; + } + break; + case STATE_BIT_CHK: + if (IMON_CHKBITS & BIT(data->count)) + data->last_chk = ev.pulse; + else if (ev.pulse) + goto err_out; + data->state = STATE_BIT_START; + break; + case STATE_BIT_START: + data->bits <<= 1; + if (!ev.pulse) + data->bits |= 1; + + if (IMON_CHKBITS & BIT(data->count)) { + if (data->last_chk != !(data->bits & 3)) + goto err_out; + } + + if (!data->count--) + data->state = STATE_FINISHED; + else + data->state = STATE_BIT_CHK; + break; + case STATE_FINISHED: + if (ev.pulse) + goto err_out; + ir_imon_decode_scancode(dev); + data->state = STATE_INACTIVE; + break; + } + } + +err_out: + dev_dbg(&dev->dev, + "iMON decode failed at state %d bitno %d (%uus %s)\n", + data->state, data->count, ev.duration, TO_STR(ev.pulse)); + + data->state = STATE_ERROR; + + return -EINVAL; +} + +/** + * ir_imon_encode() - Encode a scancode as a stream of raw events + * + * @protocol: protocol 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. + */ +static int ir_imon_encode(enum rc_proto protocol, u32 scancode, + struct ir_raw_event *events, unsigned int max) +{ + struct ir_raw_event *e = events; + int i, pulse; + + if (!max--) + return -ENOBUFS; + init_ir_raw_event_duration(e, 1, IMON_UNIT); + + for (i = IMON_BITS; i >= 0; i--) { + if (BIT(i) & IMON_CHKBITS) + pulse = !(scancode & (BIT(i) | BIT(i + 1))); + else + pulse = 0; + + if (pulse == e->pulse) { + e->duration += IMON_UNIT; + } else { + if (!max--) + return -ENOBUFS; + init_ir_raw_event_duration(++e, pulse, IMON_UNIT); + } + + pulse = !(scancode & BIT(i)); + + if (pulse == e->pulse) { + e->duration += IMON_UNIT; + } else { + if (!max--) + return -ENOBUFS; + init_ir_raw_event_duration(++e, pulse, IMON_UNIT); + } + } + + if (e->pulse) + e++; + + return e - events; +} + +static int ir_imon_register(struct rc_dev *dev) +{ + struct imon_dec *imon = &dev->raw->imon; + + imon->stick_keyboard = false; + + return 0; +} + +static struct ir_raw_handler imon_handler = { + .protocols = RC_PROTO_BIT_IMON, + .decode = ir_imon_decode, + .encode = ir_imon_encode, + .carrier = 38000, + .raw_register = ir_imon_register, + .min_timeout = IMON_UNIT * IMON_BITS * 2, +}; + +static int __init ir_imon_decode_init(void) +{ + ir_raw_handler_register(&imon_handler); + + pr_info("IR iMON protocol handler initialized\n"); + return 0; +} + +static void __exit ir_imon_decode_exit(void) +{ + ir_raw_handler_unregister(&imon_handler); +} + +module_init(ir_imon_decode_init); +module_exit(ir_imon_decode_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sean Young <sean@mess.org>"); +MODULE_DESCRIPTION("iMON IR protocol decoder"); |
