From 622ecb300345d308c8b4a983ac112b1985d7d156 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 5 Aug 2008 10:03:17 -0300 Subject: V4L/DVB (8625): saa7134: Add NEC prococol IR decoding capability This patch adds the capability of decoding NEC protocol, received via GPIO18 line. This GPIO port can trigger saa7134 IRQ. A future improvement would be to make it a little more generic to work also with GPIO16 line. A pure IRQ code didn't work, since some delays were introduced on the tests we did. A possible approach would be to use polling at a rate of 2.5 ms or less. If a new code were taken, a code similar to nec_task() could be used. However, this would add an extra overhead to kernel, and will consume more power. Due to that, we took an hybrid approach: an IRQ upper half to trigger when a new key is received and a bottom half to convert pulse-distance into a keycode. The bottom half is polling based, to improve performance. During the bottom half proccess, GPIO18 IRQ line is disabled, preventing IRQ reentrancy and improving performance a little bit. Thanks to Sistema Fenix (http://www.sistemafenix.com.br/) for sponsoring this development. Signed-off-by: Gilberto Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/saa7134/saa7134-input.c | 140 ++++++++++++++++++++++++++-- 1 file changed, 134 insertions(+), 6 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/video/saa7134/saa7134-input.c b/drivers/media/video/saa7134/saa7134-input.c index ad08d13dffd..ac6beb2df83 100644 --- a/drivers/media/video/saa7134/saa7134-input.c +++ b/drivers/media/video/saa7134/saa7134-input.c @@ -62,8 +62,11 @@ MODULE_PARM_DESC(disable_other_ir, "disable full codes of " #define i2cdprintk(fmt, arg...) if (ir_debug) \ printk(KERN_DEBUG "%s/ir: " fmt, ir->c.name , ## arg) -/** rc5 functions */ +/* 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 void nec_task(unsigned long data); +static void saa7134_nec_timer(unsigned long data); /* -------------------- GPIO generic keycode builder -------------------- */ @@ -280,7 +283,9 @@ void saa7134_input_irq(struct saa7134_dev *dev) { struct card_ir *ir = dev->remote; - if (!ir->polling && !ir->rc5_gpio) { + if (ir->nec_gpio) { + saa7134_nec_irq(dev); + } else if (!ir->polling && !ir->rc5_gpio) { build_key(dev); } else if (ir->rc5_gpio) { saa7134_rc5_irq(dev); @@ -316,6 +321,10 @@ void saa7134_ir_start(struct saa7134_dev *dev, struct card_ir *ir) ir->addr = 0x17; ir->rc5_key_timeout = ir_rc5_key_timeout; ir->rc5_remote_gap = ir_rc5_remote_gap; + } else if (ir->nec_gpio) { + setup_timer(&ir->timer_keyup, saa7134_nec_timer, + (unsigned long)dev); + tasklet_init(&ir->tlet, nec_task, (unsigned long)dev); } } @@ -335,6 +344,7 @@ int saa7134_input_init1(struct saa7134_dev *dev) u32 mask_keyup = 0; int polling = 0; int rc5_gpio = 0; + int nec_gpio = 0; int ir_type = IR_TYPE_OTHER; int err; @@ -533,6 +543,7 @@ int saa7134_input_init1(struct saa7134_dev *dev) ir->mask_keyup = mask_keyup; ir->polling = polling; ir->rc5_gpio = rc5_gpio; + ir->nec_gpio = nec_gpio; /* init input device */ snprintf(ir->name, sizeof(ir->name), "saa7134 IR (%s)", @@ -675,8 +686,125 @@ static int saa7134_rc5_irq(struct saa7134_dev *dev) return 1; } -/* ---------------------------------------------------------------------- - * Local variables: - * c-basic-offset: 8 - * End: + +/* On NEC protocol, One has 2.25 ms, and zero has 1.125 ms + The first pulse (start) has 9 + 4.5 ms */ + +static void saa7134_nec_timer(unsigned long data) +{ + struct saa7134_dev *dev = (struct saa7134_dev *) data; + struct card_ir *ir = dev->remote; + + dprintk("Cancel key repeat\n"); + + ir_input_nokey(ir->dev, &ir->ir); +} + +static void nec_task(unsigned long data) +{ + struct saa7134_dev *dev = (struct saa7134_dev *) data; + struct card_ir *ir; + struct timeval tv; + int count, pulse, oldpulse, gap; + u32 ircode = 0, not_code = 0; + int ngap = 0; + + if (!data) { + printk(KERN_ERR "saa713x/ir: Can't recover dev struct\n"); + /* GPIO will be kept disabled */ + return; + } + + ir = dev->remote; + + /* rising SAA7134_GPIO_GPRESCAN reads the status */ + saa_clearb(SAA7134_GPIO_GPMODE3, SAA7134_GPIO_GPRESCAN); + saa_setb(SAA7134_GPIO_GPMODE3, SAA7134_GPIO_GPRESCAN); + + oldpulse = saa_readl(SAA7134_GPIO_GPSTATUS0 >> 2) & ir->mask_keydown; + pulse = oldpulse; + + do_gettimeofday(&tv); + ir->base_time = tv; + + /* 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 + */ + do { + /* Wait until the end of pulse/space or 5 ms */ + for (count = 0; count < 500; 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; + } + + do_gettimeofday(&tv); + gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) + + tv.tv_usec - ir->base_time.tv_usec; + + if (!pulse) { + /* Bit 0 has 560 us, while bit 1 has 1120 us. + Do something only if bit == 1 + */ + if (ngap && (gap > 560 + 280)) { + unsigned int shift = ngap - 1; + + /* 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; + } + } + ngap++; + } + + + ir->base_time = tv; + + /* TIMEOUT - Long pulse */ + if (gap >= 5000) + break; + oldpulse = pulse; + } while (ngap < 32); + + if (ngap == 32) { + /* FIXME: should check if not_code == ~ircode */ + ir->code = ir_extract_bits(ircode, ir->mask_keycode); + + dprintk("scancode = 0x%02x (code = 0x%02x, notcode= 0x%02x)\n", + ir->code, ircode, not_code); + + ir_input_keydown(ir->dev, &ir->ir, ir->code, ir->code); + } else + dprintk("Repeat last key\n"); + + /* Keep repeating the last key */ + mod_timer(&ir->timer_keyup, jiffies + msecs_to_jiffies(150)); + + saa_setl(SAA7134_IRQ2, SAA7134_IRQ2_INTE_GPIO18); +} + +static int saa7134_nec_irq(struct saa7134_dev *dev) +{ + struct card_ir *ir = dev->remote; + + saa_clearl(SAA7134_IRQ2, SAA7134_IRQ2_INTE_GPIO18); + tasklet_schedule(&ir->tlet); + + return 1; +} -- cgit v1.2.3