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authorMauro Carvalho Chehab <mchehab@infradead.org>2008-08-05 10:03:17 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2008-10-12 09:36:47 -0200
commit622ecb300345d308c8b4a983ac112b1985d7d156 (patch)
tree2dd9156f8a5bb27826a939034d1ffa7cac671211
parentd56dc61265d2527a63ab5b0f03199a43cd89ca36 (diff)
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 <gilberto@sistemafenix.com.br> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/media/video/saa7134/saa7134-input.c140
-rw-r--r--include/media/ir-common.h5
2 files changed, 139 insertions, 6 deletions
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;
+}
diff --git a/include/media/ir-common.h b/include/media/ir-common.h
index b8e8aa91905..f5566d43894 100644
--- a/include/media/ir-common.h
+++ b/include/media/ir-common.h
@@ -25,6 +25,7 @@
#include <linux/input.h>
#include <linux/workqueue.h>
+#include <linux/interrupt.h>
#define IR_TYPE_RC5 1
#define IR_TYPE_PD 2 /* Pulse distance encoded IR */
@@ -85,6 +86,10 @@ struct card_ir {
u32 code; /* raw code under construction */
struct timeval base_time; /* time of last seen code */
int active; /* building raw code */
+
+ /* NEC decoding */
+ u32 nec_gpio;
+ struct tasklet_struct tlet;
};
void ir_input_init(struct input_dev *dev, struct ir_input_state *ir,