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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/media/rc/ir-nec-decoder.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'drivers/media/rc/ir-nec-decoder.c')
| -rw-r--r-- | drivers/media/rc/ir-nec-decoder.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-nec-decoder.c b/drivers/media/rc/ir-nec-decoder.c new file mode 100644 index 000000000..37b99432a --- /dev/null +++ b/drivers/media/rc/ir-nec-decoder.c @@ -0,0 +1,278 @@ +// SPDX-License-Identifier: GPL-2.0 +// ir-nec-decoder.c - handle NEC IR Pulse/Space protocol +// +// Copyright (C) 2010 by Mauro Carvalho Chehab + +#include <linux/bitrev.h> +#include <linux/module.h> +#include "rc-core-priv.h" + +#define NEC_NBITS 32 +#define NEC_UNIT 563 /* us */ +#define NEC_HEADER_PULSE (16 * NEC_UNIT) +#define NECX_HEADER_PULSE (8 * NEC_UNIT) /* Less common NEC variant */ +#define NEC_HEADER_SPACE (8 * NEC_UNIT) +#define NEC_REPEAT_SPACE (4 * NEC_UNIT) +#define NEC_BIT_PULSE (1 * NEC_UNIT) +#define NEC_BIT_0_SPACE (1 * NEC_UNIT) +#define NEC_BIT_1_SPACE (3 * NEC_UNIT) +#define NEC_TRAILER_PULSE (1 * NEC_UNIT) +#define NEC_TRAILER_SPACE (10 * NEC_UNIT) /* even longer in reality */ +#define NECX_REPEAT_BITS 1 + +enum nec_state { + STATE_INACTIVE, + STATE_HEADER_SPACE, + STATE_BIT_PULSE, + STATE_BIT_SPACE, + STATE_TRAILER_PULSE, + STATE_TRAILER_SPACE, +}; + +/** + * ir_nec_decode() - Decode one NEC 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_nec_decode(struct rc_dev *dev, struct ir_raw_event ev) +{ + struct nec_dec *data = &dev->raw->nec; + u32 scancode; + enum rc_proto rc_proto; + u8 address, not_address, command, not_command; + + if (!is_timing_event(ev)) { + if (ev.overflow) + data->state = STATE_INACTIVE; + return 0; + } + + dev_dbg(&dev->dev, "NEC decode started at state %d (%uus %s)\n", + data->state, ev.duration, TO_STR(ev.pulse)); + + switch (data->state) { + + case STATE_INACTIVE: + if (!ev.pulse) + break; + + if (eq_margin(ev.duration, NEC_HEADER_PULSE, NEC_UNIT * 2)) { + data->is_nec_x = false; + data->necx_repeat = false; + } else if (eq_margin(ev.duration, NECX_HEADER_PULSE, NEC_UNIT / 2)) + data->is_nec_x = true; + else + break; + + data->count = 0; + data->state = STATE_HEADER_SPACE; + return 0; + + case STATE_HEADER_SPACE: + if (ev.pulse) + break; + + if (eq_margin(ev.duration, NEC_HEADER_SPACE, NEC_UNIT)) { + data->state = STATE_BIT_PULSE; + return 0; + } else if (eq_margin(ev.duration, NEC_REPEAT_SPACE, NEC_UNIT / 2)) { + data->state = STATE_TRAILER_PULSE; + return 0; + } + + break; + + case STATE_BIT_PULSE: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, NEC_BIT_PULSE, NEC_UNIT / 2)) + break; + + data->state = STATE_BIT_SPACE; + return 0; + + case STATE_BIT_SPACE: + if (ev.pulse) + break; + + if (data->necx_repeat && data->count == NECX_REPEAT_BITS && + geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2)) { + dev_dbg(&dev->dev, "Repeat last key\n"); + rc_repeat(dev); + data->state = STATE_INACTIVE; + return 0; + } else if (data->count > NECX_REPEAT_BITS) + data->necx_repeat = false; + + data->bits <<= 1; + if (eq_margin(ev.duration, NEC_BIT_1_SPACE, NEC_UNIT / 2)) + data->bits |= 1; + else if (!eq_margin(ev.duration, NEC_BIT_0_SPACE, NEC_UNIT / 2)) + break; + data->count++; + + if (data->count == NEC_NBITS) + data->state = STATE_TRAILER_PULSE; + else + data->state = STATE_BIT_PULSE; + + return 0; + + case STATE_TRAILER_PULSE: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, NEC_TRAILER_PULSE, NEC_UNIT / 2)) + break; + + data->state = STATE_TRAILER_SPACE; + return 0; + + case STATE_TRAILER_SPACE: + if (ev.pulse) + break; + + if (!geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2)) + break; + + if (data->count == NEC_NBITS) { + address = bitrev8((data->bits >> 24) & 0xff); + not_address = bitrev8((data->bits >> 16) & 0xff); + command = bitrev8((data->bits >> 8) & 0xff); + not_command = bitrev8((data->bits >> 0) & 0xff); + + scancode = ir_nec_bytes_to_scancode(address, + not_address, + command, + not_command, + &rc_proto); + + if (data->is_nec_x) + data->necx_repeat = true; + + rc_keydown(dev, rc_proto, scancode, 0); + } else { + rc_repeat(dev); + } + + data->state = STATE_INACTIVE; + return 0; + } + + dev_dbg(&dev->dev, "NEC decode failed at count %d state %d (%uus %s)\n", + data->count, data->state, ev.duration, TO_STR(ev.pulse)); + data->state = STATE_INACTIVE; + return -EINVAL; +} + +/** + * ir_nec_scancode_to_raw() - encode an NEC scancode ready for modulation. + * @protocol: specific protocol to use + * @scancode: a single NEC scancode. + */ +static u32 ir_nec_scancode_to_raw(enum rc_proto protocol, u32 scancode) +{ + unsigned int addr, addr_inv, data, data_inv; + + data = scancode & 0xff; + + if (protocol == RC_PROTO_NEC32) { + /* 32-bit NEC (used by Apple and TiVo remotes) */ + /* scan encoding: aaAAddDD */ + addr_inv = (scancode >> 24) & 0xff; + addr = (scancode >> 16) & 0xff; + data_inv = (scancode >> 8) & 0xff; + } else if (protocol == RC_PROTO_NECX) { + /* Extended NEC */ + /* scan encoding AAaaDD */ + addr = (scancode >> 16) & 0xff; + addr_inv = (scancode >> 8) & 0xff; + data_inv = data ^ 0xff; + } else { + /* Normal NEC */ + /* scan encoding: AADD */ + addr = (scancode >> 8) & 0xff; + addr_inv = addr ^ 0xff; + data_inv = data ^ 0xff; + } + + /* raw encoding: ddDDaaAA */ + return data_inv << 24 | + data << 16 | + addr_inv << 8 | + addr; +} + +static const struct ir_raw_timings_pd ir_nec_timings = { + .header_pulse = NEC_HEADER_PULSE, + .header_space = NEC_HEADER_SPACE, + .bit_pulse = NEC_BIT_PULSE, + .bit_space[0] = NEC_BIT_0_SPACE, + .bit_space[1] = NEC_BIT_1_SPACE, + .trailer_pulse = NEC_TRAILER_PULSE, + .trailer_space = NEC_TRAILER_SPACE, + .msb_first = 0, +}; + +/** + * ir_nec_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_nec_encode(enum rc_proto protocol, u32 scancode, + struct ir_raw_event *events, unsigned int max) +{ + struct ir_raw_event *e = events; + int ret; + u32 raw; + + /* Convert a NEC scancode to raw NEC data */ + raw = ir_nec_scancode_to_raw(protocol, scancode); + + /* Modulate the raw data using a pulse distance modulation */ + ret = ir_raw_gen_pd(&e, max, &ir_nec_timings, NEC_NBITS, raw); + if (ret < 0) + return ret; + + return e - events; +} + +static struct ir_raw_handler nec_handler = { + .protocols = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | + RC_PROTO_BIT_NEC32, + .decode = ir_nec_decode, + .encode = ir_nec_encode, + .carrier = 38000, + .min_timeout = NEC_TRAILER_SPACE, +}; + +static int __init ir_nec_decode_init(void) +{ + ir_raw_handler_register(&nec_handler); + + printk(KERN_INFO "IR NEC protocol handler initialized\n"); + return 0; +} + +static void __exit ir_nec_decode_exit(void) +{ + ir_raw_handler_unregister(&nec_handler); +} + +module_init(ir_nec_decode_init); +module_exit(ir_nec_decode_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Mauro Carvalho Chehab"); +MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); +MODULE_DESCRIPTION("NEC IR protocol decoder"); |
