On Thu, 2010-04-01 at 14:56 -0300, Mauro Carvalho Chehab wrote:
> Adds a method to pass IR raw pulse/code events into ir-core. This is
> needed in order to support LIRC. It also helps to move common code
> from the drivers into the core.
>
> In order to allow testing, it implements a simple NEC protocol decoder
> at ir-nec-decoder.c file. The logic is about the same used at saa7134
> driver that handles Avermedia M135A and Encore FM53 boards.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
>
> create mode 100644 drivers/media/IR/ir-nec-decoder.c
> create mode 100644 drivers/media/IR/ir-raw-event.c
Hi Mauro,
I haven't taken a very hard look at this since I'm very busy this month.
It looks OK so far. I do have some comments....
> diff --git a/drivers/media/IR/Makefile b/drivers/media/IR/Makefile
> index 171890e..18794c7 100644
> --- a/drivers/media/IR/Makefile
> +++ b/drivers/media/IR/Makefile
> @@ -1,5 +1,5 @@
> ir-common-objs := ir-functions.o ir-keymaps.o
> -ir-core-objs := ir-keytable.o ir-sysfs.o
> +ir-core-objs := ir-keytable.o ir-sysfs.o ir-raw-event.o ir-nec-decoder.o
>
> obj-$(CONFIG_IR_CORE) += ir-core.o
> obj-$(CONFIG_VIDEO_IR) += ir-common.o
> diff --git a/drivers/media/IR/ir-nec-decoder.c b/drivers/media/IR/ir-nec-decoder.c
> new file mode 100644
> index 0000000..16360eb
> --- /dev/null
> +++ b/drivers/media/IR/ir-nec-decoder.c
> @@ -0,0 +1,131 @@
> +/* ir-raw-event.c - handle IR Pulse/Space event
> + *
> + * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <media/ir-core.h>
> +
> +/* Start time: 4.5 ms */
> +#define MIN_START_TIME 3900000
> +#define MAX_START_TIME 5100000
Hmmm.
An NEC header pulse is nominally 16 * 560 us = 8.96 ms
An NEC header space is nominally 8 * 560 us = 4.48 ms
An NEC repeat header space is nominally 4 * 560 us = 2.24 ms
I think you need a more explicit name than {MIN,MAX}_START_TIME.
> +/* Pulse time: 560 us */
> +#define MIN_PULSE_TIME 460000
> +#define MAX_PULSE_TIME 660000
> +
> +/* Bit 1 space time: 2.25ms-560 us */
> +#define MIN_BIT1_TIME 1490000
> +#define MAX_BIT1_TIME 1890000
> +
> +/* Bit 0 space time: 1.12ms-560 us */
> +#define MIN_BIT0_TIME 360000
> +#define MAX_BIT0_TIME 760000
> +
The fundamental unit of time in the NEC protocol is ideally:
4192/197 cycles / 38 kHz = 559978.6 ns ~= 560 ns
All other time durations in the NEC protocol are multiples of this unit.
See:
http://linuxtv.org/hg/~awalls/cx23885-ir2/rev/2cfef53b95a2#l1.96
If you define the your above constants in terms of that time unit, it
makes the tolerances you added in explicitly visible when reading the
source.
> +/** Decode NEC pulsecode. This code can take up to 76.5 ms to run.
> + Unfortunately, using IRQ to decode pulse didn't work, since it uses
> + a pulse train of 38KHz. This means one pulse on each 52 us
> +*/
> +
> +int ir_nec_decode(struct input_dev *input_dev,
> + struct ir_raw_event *evs,
> + int len)
> +{
> + int i, count = -1;
> + int ircode = 0, not_code = 0;
> +#if 0
> + /* Needed only after porting the event code to the decoder */
> + struct ir_input_dev *ir = input_get_drvdata(input_dev);
> +#endif
> +
> + /* Be sure that the first event is an start one and is a pulse */
> + for (i = 0; i < len; i++) {
> + if (evs[i].type & (IR_START_EVENT | IR_PULSE))
> + break;
> + }
> + i++; /* First event doesn't contain data */
> +
> + if (i >= len)
> + return 0;
> +
> + /* First space should have 4.5 ms otherwise is not NEC protocol */
> + if ((evs[i].delta.tv_nsec < MIN_START_TIME) |
> + (evs[i].delta.tv_nsec > MAX_START_TIME) |
> + (evs[i].type != IR_SPACE))
> + goto err;
> +
> + /*
> + * FIXME: need to implement the repeat sequence
> + */
I have an NEC protocol decoder here:
http://linuxtv.org/hg/~awalls/cx23885-ir2/rev/2cfef53b95a2
If you would find it useful, please feel free to borrow ideas or parts
of the code to implement any features you are missing. (That code works
by converting a mark-space pair to an "nec_symbol", and then taking
action based on the symbol.)
I suspect you will want to implement the repeat sequence. It is hard
not to get a repeat sequence from a remote.
NEC ideally sends a repeat at intervals of:
4192 cycles * 38 kHz = 110.316 ms
> + count = 0;
> + for (i++; i < len; i++) {
> + int bit;
> +
> + if ((evs[i].delta.tv_nsec < MIN_PULSE_TIME) |
> + (evs[i].delta.tv_nsec > MAX_PULSE_TIME) |
> + (evs[i].type != IR_PULSE))
> + goto err;
> +
> + if (++i >= len)
> + goto err;
> + if (evs[i].type != IR_SPACE)
> + goto err;
> +
> + if ((evs[i].delta.tv_nsec > MIN_BIT1_TIME) &&
> + (evs[i].delta.tv_nsec < MAX_BIT1_TIME))
> + bit = 1;
> + else if ((evs[i].delta.tv_nsec > MIN_BIT0_TIME) &&
> + (evs[i].delta.tv_nsec < MAX_BIT0_TIME))
> + bit = 0;
> + else
> + goto err;
> +
> + if (bit) {
> + int shift = count;
> + /* Address first, then command */
> + if (shift < 8) {
> + shift += 8;
> + ircode |= 1 << shift;
> + } else if (shift < 16) {
> + not_code |= 1 << shift;
> + } else if (shift < 24) {
> + shift -= 16;
> + ircode |= 1 << shift;
> + } else {
> + shift -= 24;
> + not_code |= 1 << shift;
> + }
> + }
> + if (++count == 32)
> + break;
> + }
> +
> + /*
> + * Fixme: may need to accept Extended NEC protocol?
> + */
Both of the NEC remotes that I own use the extended protocol, IIRC.
> + if ((ircode & ~not_code) != ircode) {
> + IR_dprintk(1, "NEC checksum error: code 0x%04x, not-code 0x%04x\n",
> + ircode, not_code);
> + return -EINVAL;
> + }
> +
> + IR_dprintk(1, "NEC scancode 0x%04x\n", ircode);
> +
> + return ircode;
> +err:
> + IR_dprintk(1, "NEC decoded failed at bit %d while decoding %luus time\n",
> + count, (evs[i].delta.tv_nsec + 500) / 1000);
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(ir_nec_decode);
> diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c
> new file mode 100644
> index 0000000..9c71ac8
> --- /dev/null
> +++ b/drivers/media/IR/ir-raw-event.c
> @@ -0,0 +1,117 @@
> +/* ir-raw-event.c - handle IR Pulse/Space event
> + *
> + * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <media/ir-core.h>
> +
> +/* Define the max number of bit transitions per IR keycode */
> +#define MAX_IR_EVENT_SIZE 256
> +
> +int ir_raw_event_register(struct input_dev *input_dev)
> +{
> + struct ir_input_dev *ir = input_get_drvdata(input_dev);
> + int rc, size;
> +
> + ir->raw = kzalloc(sizeof(*ir->raw), GFP_KERNEL);
> +
> + size = sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE * 2;
> + size = roundup_pow_of_two(size);
> +
> + rc = kfifo_alloc(&ir->raw->kfifo, size, GFP_KERNEL);
> +
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(ir_raw_event_register);
> +
> +void ir_raw_event_unregister(struct input_dev *input_dev)
> +{
> + struct ir_input_dev *ir = input_get_drvdata(input_dev);
> +
> + if (!ir->raw)
> + return;
> +
> + kfifo_free(&ir->raw->kfifo);
> + kfree(ir->raw);
> + ir->raw = NULL;
> +}
> +EXPORT_SYMBOL_GPL(ir_raw_event_unregister);
> +
> +int ir_raw_event_store(struct input_dev *input_dev, enum raw_event_type type)
> +{
> + struct ir_input_dev *ir = input_get_drvdata(input_dev);
> + struct timespec ts;
> + struct ir_raw_event event;
> + int rc;
> +
> + if (!ir->raw)
> + return -EINVAL;
> +
> + event.type = type;
> + event.delta.tv_sec = 0;
> + event.delta.tv_nsec = 0;
> +
> + ktime_get_ts(&ts);
> +
> + if (timespec_equal(&ir->raw->last_event, &event.delta))
> + event.type |= IR_START_EVENT;
> + else
> + event.delta = timespec_sub(ts, ir->raw->last_event);
> +
> + memcpy(&ir->raw->last_event, &ts, sizeof(ts));
> +
> + if (event.delta.tv_sec) {
> + event.type |= IR_START_EVENT;
> + event.delta.tv_sec = 0;
> + event.delta.tv_nsec = 0;
> + }
> +
> + kfifo_in(&ir->raw->kfifo, &event, sizeof(event));
> +
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(ir_raw_event_store);
> +
> +int ir_raw_event_handle(struct input_dev *input_dev)
> +{
> + struct ir_input_dev *ir = input_get_drvdata(input_dev);
> + int rc;
> + struct ir_raw_event *evs;
> + int len, i;
> +
> + /*
> + * Store the events into a temporary buffer. This allows calling more than
> + * one decoder to deal with the received data
> + */
> + len = kfifo_len(&ir->raw->kfifo) / sizeof(*evs);
> + if (!len)
> + return 0;
> + evs = kmalloc(len * sizeof(*evs), GFP_ATOMIC);
> +
> + for (i = 0; i < len; i++) {
> + rc = kfifo_out(&ir->raw->kfifo, &evs[i], sizeof(*evs));
> + if (rc != sizeof(*evs)) {
> + IR_dprintk(1, "overflow error: received %d instead of %zd\n",
> + rc, sizeof(*evs));
> + return -EINVAL;
> + }
> + IR_dprintk(2, "event type %d, time before event: %07luus\n",
> + evs[i].type, (evs[i].delta.tv_nsec + 500) / 1000);
> + }
> +
> + rc = ir_nec_decode(input_dev, evs, len);
> +
> + kfree(evs);
> +
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(ir_raw_event_handle);
> diff --git a/drivers/media/video/saa7134/saa7134-input.c b/drivers/media/video/saa7134/saa7134-input.c
> index 8187928..7382995 100644
> --- a/drivers/media/video/saa7134/saa7134-input.c
> +++ b/drivers/media/video/saa7134/saa7134-input.c
> @@ -67,6 +67,7 @@ MODULE_PARM_DESC(disable_other_ir, "disable full codes of "
> /* Helper functions for RC5 and NEC decoding at GPIO16 or GPIO18 */
> static int saa7134_rc5_irq(struct saa7134_dev *dev);
> static int saa7134_nec_irq(struct saa7134_dev *dev);
> +static int saa7134_raw_decode_irq(struct saa7134_dev *dev);
> static void nec_task(unsigned long data);
> static void saa7134_nec_timer(unsigned long data);
>
> @@ -402,10 +403,12 @@ void saa7134_input_irq(struct saa7134_dev *dev)
>
> if (ir->nec_gpio) {
> saa7134_nec_irq(dev);
> - } else if (!ir->polling && !ir->rc5_gpio) {
> + } else if (!ir->polling && !ir->rc5_gpio && !ir->raw_decode) {
> build_key(dev);
> } else if (ir->rc5_gpio) {
> saa7134_rc5_irq(dev);
> + } else if (ir->raw_decode) {
> + saa7134_raw_decode_irq(dev);
> }
> }
>
> @@ -418,6 +421,23 @@ static void saa7134_input_timer(unsigned long data)
> mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling));
> }
>
> +void ir_raw_decode_timer_end(unsigned long data)
> +{
> + struct saa7134_dev *dev = (struct saa7134_dev *)data;
> + struct card_ir *ir = dev->remote;
> + int rc;
> +
> + /*
> + * FIXME: the IR key handling code should be called by the decoder,
> + * after implementing the repeat mode
> + */
> + rc = ir_raw_event_handle(dev->remote->dev);
> + if (rc >= 0) {
> + ir_input_keydown(ir->dev, &ir->ir, rc);
> + ir_input_nokey(ir->dev, &ir->ir);
> + }
> +}
> +
> void saa7134_ir_start(struct saa7134_dev *dev, struct card_ir *ir)
> {
> if (ir->running)
> @@ -446,6 +466,11 @@ void saa7134_ir_start(struct saa7134_dev *dev, struct card_ir *ir)
> setup_timer(&ir->timer_keyup, saa7134_nec_timer,
> (unsigned long)dev);
> tasklet_init(&ir->tlet, nec_task, (unsigned long)dev);
> + } else if (ir->raw_decode) {
> + /* set timer_end for code completion */
> + init_timer(&ir->timer_end);
> + ir->timer_end.function = ir_raw_decode_timer_end;
> + ir->timer_end.data = (unsigned long)dev;
> }
> }
>
> @@ -461,6 +486,9 @@ void saa7134_ir_stop(struct saa7134_dev *dev)
> del_timer_sync(&ir->timer_end);
> else if (ir->nec_gpio)
> tasklet_kill(&ir->tlet);
> + else if (ir->raw_decode)
> + del_timer_sync(&ir->timer_end);
> +
> ir->running = 0;
> }
>
> @@ -508,6 +536,7 @@ int saa7134_input_init1(struct saa7134_dev *dev)
> int polling = 0;
> int rc5_gpio = 0;
> int nec_gpio = 0;
> + int raw_decode = 0;
> u64 ir_type = IR_TYPE_OTHER;
> int err;
>
> @@ -573,7 +602,7 @@ int saa7134_input_init1(struct saa7134_dev *dev)
> ir_codes = &ir_codes_avermedia_m135a_rm_jx_table;
> mask_keydown = 0x0040000;
> mask_keycode = 0xffff;
> - nec_gpio = 1;
> + raw_decode = 1;
> break;
> case SAA7134_BOARD_AVERMEDIA_777:
> case SAA7134_BOARD_AVERMEDIA_A16AR:
> @@ -754,6 +783,7 @@ int saa7134_input_init1(struct saa7134_dev *dev)
> ir->polling = polling;
> ir->rc5_gpio = rc5_gpio;
> ir->nec_gpio = nec_gpio;
> + ir->raw_decode = raw_decode;
>
> /* init input device */
> snprintf(ir->name, sizeof(ir->name), "saa7134 IR (%s)",
> @@ -761,7 +791,7 @@ int saa7134_input_init1(struct saa7134_dev *dev)
> snprintf(ir->phys, sizeof(ir->phys), "pci-%s/ir0",
> pci_name(dev->pci));
>
> - if (ir_codes->ir_type != IR_TYPE_OTHER) {
> + if (ir_codes->ir_type != IR_TYPE_OTHER && !raw_decode) {
> ir->props.allowed_protos = IR_TYPE_RC5 | IR_TYPE_NEC;
> ir->props.priv = dev;
> ir->props.change_protocol = saa7134_ir_change_protocol;
> @@ -789,6 +819,11 @@ int saa7134_input_init1(struct saa7134_dev *dev)
> err = ir_input_register(ir->dev, ir_codes, &ir->props, MODULE_NAME);
> if (err)
> goto err_out_stop;
> + if (ir_codes->ir_type != IR_TYPE_OTHER) {
> + err = ir_raw_event_register(ir->dev);
> + if (err)
> + goto err_out_stop;
> + }
>
> saa7134_ir_start(dev, ir);
>
> @@ -812,6 +847,7 @@ void saa7134_input_fini(struct saa7134_dev *dev)
> return;
>
> saa7134_ir_stop(dev);
> + ir_raw_event_unregister(dev->remote->dev);
> ir_input_unregister(dev->remote->dev);
> kfree(dev->remote);
> dev->remote = NULL;
> @@ -918,6 +954,48 @@ void saa7134_probe_i2c_ir(struct saa7134_dev *dev)
> i2c_new_device(&dev->i2c_adap, &info);
> }
>
> +static int saa7134_raw_decode_irq(struct saa7134_dev *dev)
> +{
> + struct card_ir *ir = dev->remote;
> + unsigned long timeout;
> + int count, pulse, oldpulse;
> +
> + /* Disable IR IRQ line */
> + saa_clearl(SAA7134_IRQ2, SAA7134_IRQ2_INTE_GPIO18);
> +
> + /* Generate initial event */
> + saa_clearb(SAA7134_GPIO_GPMODE3, SAA7134_GPIO_GPRESCAN);
> + saa_setb(SAA7134_GPIO_GPMODE3, SAA7134_GPIO_GPRESCAN);
> + pulse = saa_readl(SAA7134_GPIO_GPSTATUS0 >> 2) & ir->mask_keydown;
> + ir_raw_event_store(dev->remote->dev, pulse? IR_PULSE : IR_SPACE);
> +
> +#if 1
> + /* Wait up to 10 ms for event change */
> + oldpulse = pulse;
> + for (count = 0; count < 1000; count++) {
> + udelay(10);
> + /* rising SAA7134_GPIO_GPRESCAN reads the status */
> + saa_clearb(SAA7134_GPIO_GPMODE3, SAA7134_GPIO_GPRESCAN);
> + saa_setb(SAA7134_GPIO_GPMODE3, SAA7134_GPIO_GPRESCAN);
> + pulse = saa_readl(SAA7134_GPIO_GPSTATUS0 >> 2)
> + & ir->mask_keydown;
> + if (pulse != oldpulse)
> + break;
> + }
> +
> + /* Store final event */
> + ir_raw_event_store(dev->remote->dev, pulse? IR_PULSE : IR_SPACE);
> +#endif
> + /* Wait 15 ms before deciding to do something else */
> + timeout = jiffies + jiffies_to_msecs(15);
> + mod_timer(&ir->timer_end, timeout);
> +
> + /* Enable IR IRQ line */
> + saa_setl(SAA7134_IRQ2, SAA7134_IRQ2_INTE_GPIO18);
> +
> + return 1;
> +}
> +
> static int saa7134_rc5_irq(struct saa7134_dev *dev)
> {
> struct card_ir *ir = dev->remote;
> @@ -960,7 +1038,6 @@ static int saa7134_rc5_irq(struct saa7134_dev *dev)
> return 1;
> }
>
> -
> /* On NEC protocol, One has 2.25 ms, and zero has 1.125 ms
> The first pulse (start) has 9 + 4.5 ms
> */
> diff --git a/include/media/ir-common.h b/include/media/ir-common.h
> index 41469b7..87f2ec7 100644
> --- a/include/media/ir-common.h
> +++ b/include/media/ir-common.h
> @@ -82,6 +82,9 @@ struct card_ir {
> /* NEC decoding */
> u32 nec_gpio;
> struct tasklet_struct tlet;
> +
> + /* IR core raw decoding */
> + u32 raw_decode;
> };
>
> /* Routines from ir-functions.c */
> diff --git a/include/media/ir-core.h b/include/media/ir-core.h
> index 1eae72d..369969d 100644
> --- a/include/media/ir-core.h
> +++ b/include/media/ir-core.h
> @@ -16,6 +16,8 @@
>
> #include <linux/input.h>
> #include <linux/spinlock.h>
> +#include <linux/kfifo.h>
> +#include <linux/time.h>
>
> extern int ir_core_debug;
> #define IR_dprintk(level, fmt, arg...) if (ir_core_debug >= level) \
> @@ -27,6 +29,13 @@ extern int ir_core_debug;
> #define IR_TYPE_NEC (1 << 2)
> #define IR_TYPE_OTHER (((u64)1) << 63l)
>
> +enum raw_event_type {
> + IR_SPACE = (1 << 0),
> + IR_PULSE = (1 << 1),
> + IR_START_EVENT = (1 << 2),
> + IR_STOP_EVENT = (1 << 3),
> +};
> +
Why are these events encoded as bit flags? Shouldn't they all be
orthogonal?
Regards,
Andy
> struct ir_scancode {
> u16 scancode;
> u32 keycode;
> @@ -46,6 +55,15 @@ struct ir_dev_props {
> int (*change_protocol)(void *priv, u64 ir_type);
> };
>
> +struct ir_raw_event {
> + struct timespec delta; /* Time spent before event */
> + enum raw_event_type type; /* event type */
> +};
> +
> +struct ir_raw_event_ctrl {
> + struct kfifo kfifo; /* fifo for the pulse/space events */
> + struct timespec last_event; /* when last event occurred */
> +};
>
> struct ir_input_dev {
> struct device dev; /* device */
> @@ -53,7 +71,9 @@ struct ir_input_dev {
> struct ir_scancode_table rc_tab; /* scan/key table */
> unsigned long devno; /* device number */
> const struct ir_dev_props *props; /* Device properties */
> + struct ir_raw_event_ctrl *raw; /* for raw pulse/space events */
> };
> +
> #define to_ir_input_dev(_attr) container_of(_attr, struct ir_input_dev, attr)
>
> /* Routines from ir-keytable.c */
> @@ -72,4 +92,16 @@ void ir_input_unregister(struct input_dev *input_dev);
> int ir_register_class(struct input_dev *input_dev);
> void ir_unregister_class(struct input_dev *input_dev);
>
> +/* Routines from ir-raw-event.c */
> +int ir_raw_event_register(struct input_dev *input_dev);
> +void ir_raw_event_unregister(struct input_dev *input_dev);
> +int ir_raw_event_store(struct input_dev *input_dev, enum raw_event_type type);
> +int ir_raw_event_handle(struct input_dev *input_dev);
> +
> +/* from ir-nec-decoder.c */
> +int ir_nec_decode(struct input_dev *input_dev,
> + struct ir_raw_event *evs,
> + int len);
> +
> +
> #endif
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