V4L/DVB: ir-core: Add JVC support to ir-core

This patch adds a JVC decoder to ir-core.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 320 insertions, 0 deletions

diff --git a/drivers/media/IR/ir-jvc-decoder.c b/drivers/media/IR/ir-jvc-decoder.c
new file mode 100644
index 000000000000..0b804944cbb0
--- /dev/null
+++ b/drivers/media/IR/ir-jvc-decoder.c
@@ -0,0 +1,320 @@
+/* ir-jvc-decoder.c - handle JVC IR Pulse/Space protocol
+ *
+ * Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
+ *
+ * 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 <linux/bitrev.h>
+#include "ir-core-priv.h"
+
+#define JVC_NBITS               16              /* dev(8) + func(8) */
+#define JVC_UNIT                525000          /* ns */
+#define JVC_HEADER_PULSE        (16 * JVC_UNIT) /* lack of header -> repeat */
+#define JVC_HEADER_SPACE        (8  * JVC_UNIT)
+#define JVC_BIT_PULSE           (1  * JVC_UNIT)
+#define JVC_BIT_0_SPACE         (1  * JVC_UNIT)
+#define JVC_BIT_1_SPACE         (3  * JVC_UNIT)
+#define JVC_TRAILER_PULSE       (1  * JVC_UNIT)
+#define JVC_TRAILER_SPACE       (35 * JVC_UNIT)
+
+/* Used to register jvc_decoder clients */
+static LIST_HEAD(decoder_list);
+DEFINE_SPINLOCK(decoder_lock);
+
+enum jvc_state {
+        STATE_INACTIVE,
+        STATE_HEADER_SPACE,
+        STATE_BIT_PULSE,
+        STATE_BIT_SPACE,
+        STATE_TRAILER_PULSE,
+        STATE_TRAILER_SPACE,
+};
+
+struct decoder_data {
+        struct list_head        list;
+        struct ir_input_dev     *ir_dev;
+        int                     enabled:1;
+
+        /* State machine control */
+        enum jvc_state          state;
+        u16                     jvc_bits;
+        u16                     jvc_old_bits;
+        unsigned                count;
+        bool                    first;
+        bool                    toggle;
+};
+
+
+/**
+ * get_decoder_data()   - gets decoder data
+ * @input_dev:  input device
+ *
+ * Returns the struct decoder_data that corresponds to a device
+ */
+static struct decoder_data *get_decoder_data(struct  ir_input_dev *ir_dev)
+{
+        struct decoder_data *data = NULL;
+
+        spin_lock(&decoder_lock);
+        list_for_each_entry(data, &decoder_list, list) {
+                if (data->ir_dev == ir_dev)
+                        break;
+        }
+        spin_unlock(&decoder_lock);
+        return data;
+}
+
+static ssize_t store_enabled(struct device *d,
+                             struct device_attribute *mattr,
+                             const char *buf,
+                             size_t len)
+{
+        unsigned long value;
+        struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+        struct decoder_data *data = get_decoder_data(ir_dev);
+
+        if (!data)
+                return -EINVAL;
+
+        if (strict_strtoul(buf, 10, &value) || value > 1)
+                return -EINVAL;
+
+        data->enabled = value;
+
+        return len;
+}
+
+static ssize_t show_enabled(struct device *d,
+                             struct device_attribute *mattr, char *buf)
+{
+        struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+        struct decoder_data *data = get_decoder_data(ir_dev);
+
+        if (!data)
+                return -EINVAL;
+
+        if (data->enabled)
+                return sprintf(buf, "1\n");
+        else
+        return sprintf(buf, "0\n");
+}
+
+static DEVICE_ATTR(enabled, S_IRUGO | S_IWUSR, show_enabled, store_enabled);
+
+static struct attribute *decoder_attributes[] = {
+        &dev_attr_enabled.attr,
+        NULL
+};
+
+static struct attribute_group decoder_attribute_group = {
+        .name   = "jvc_decoder",
+        .attrs  = decoder_attributes,
+};
+
+/**
+ * ir_jvc_decode() - Decode one JVC pulse or space
+ * @input_dev:  the struct input_dev descriptor of the device
+ * @duration:   the struct ir_raw_event descriptor of the pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
+ */
+static int ir_jvc_decode(struct input_dev *input_dev, struct ir_raw_event ev)
+{
+        struct decoder_data *data;
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+
+        data = get_decoder_data(ir_dev);
+        if (!data)
+                return -EINVAL;
+
+        if (!data->enabled)
+                return 0;
+
+        if (IS_RESET(ev)) {
+                data->state = STATE_INACTIVE;
+                return 0;
+        }
+
+        if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2))
+                goto out;
+
+        IR_dprintk(2, "JVC decode started at state %d (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+
+        switch (data->state) {
+
+        case STATE_INACTIVE:
+                if (!ev.pulse)
+                        break;
+
+                if (!eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
+                        break;
+
+                data->count = 0;
+                data->first = true;
+                data->toggle = !data->toggle;
+                data->state = STATE_HEADER_SPACE;
+                return 0;
+
+        case STATE_HEADER_SPACE:
+                if (ev.pulse)
+                        break;
+
+                if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2))
+                        break;
+
+                data->state = STATE_BIT_PULSE;
+                return 0;
+
+        case STATE_BIT_PULSE:
+                if (!ev.pulse)
+                        break;
+
+                if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2))
+                        break;
+
+                data->state = STATE_BIT_SPACE;
+                return 0;
+
+        case STATE_BIT_SPACE:
+                if (ev.pulse)
+                        break;
+
+                data->jvc_bits <<= 1;
+                if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) {
+                        data->jvc_bits |= 1;
+                        decrease_duration(&ev, JVC_BIT_1_SPACE);
+                } else if (eq_margin(ev.duration, JVC_BIT_0_SPACE, JVC_UNIT / 2))
+                        decrease_duration(&ev, JVC_BIT_0_SPACE);
+                else
+                        break;
+                data->count++;
+
+                if (data->count == JVC_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, JVC_TRAILER_PULSE, JVC_UNIT / 2))
+                        break;
+
+                data->state = STATE_TRAILER_SPACE;
+                return 0;
+
+        case STATE_TRAILER_SPACE:
+                if (ev.pulse)
+                        break;
+
+                if (!geq_margin(ev.duration, JVC_TRAILER_SPACE, JVC_UNIT / 2))
+                        break;
+
+                if (data->first) {
+                        u32 scancode;
+                        scancode = (bitrev8((data->jvc_bits >> 8) & 0xff) << 8) |
+                                   (bitrev8((data->jvc_bits >> 0) & 0xff) << 0);
+                        IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
+                        ir_keydown(input_dev, scancode, data->toggle);
+                        data->first = false;
+                        data->jvc_old_bits = data->jvc_bits;
+                } else if (data->jvc_bits == data->jvc_old_bits) {
+                        IR_dprintk(1, "JVC repeat\n");
+                        ir_repeat(input_dev);
+                } else {
+                        IR_dprintk(1, "JVC invalid repeat msg\n");
+                        break;
+                }
+
+                data->count = 0;
+                data->state = STATE_BIT_PULSE;
+                return 0;
+        }
+
+out:
+        IR_dprintk(1, "JVC decode failed at state %d (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+        data->state = STATE_INACTIVE;
+        return -EINVAL;
+}
+
+static int ir_jvc_register(struct input_dev *input_dev)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        struct decoder_data *data;
+        int rc;
+
+        rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+        if (rc < 0)
+                return rc;
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data) {
+                sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+                return -ENOMEM;
+        }
+
+        data->ir_dev = ir_dev;
+        data->enabled = 1;
+
+        spin_lock(&decoder_lock);
+        list_add_tail(&data->list, &decoder_list);
+        spin_unlock(&decoder_lock);
+
+        return 0;
+}
+
+static int ir_jvc_unregister(struct input_dev *input_dev)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        static struct decoder_data *data;
+
+        data = get_decoder_data(ir_dev);
+        if (!data)
+                return 0;
+
+        sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+
+        spin_lock(&decoder_lock);
+        list_del(&data->list);
+        spin_unlock(&decoder_lock);
+
+        return 0;
+}
+
+static struct ir_raw_handler jvc_handler = {
+        .decode         = ir_jvc_decode,
+        .raw_register   = ir_jvc_register,
+        .raw_unregister = ir_jvc_unregister,
+};
+
+static int __init ir_jvc_decode_init(void)
+{
+        ir_raw_handler_register(&jvc_handler);
+
+        printk(KERN_INFO "IR JVC protocol handler initialized\n");
+        return 0;
+}
+
+static void __exit ir_jvc_decode_exit(void)
+{
+        ir_raw_handler_unregister(&jvc_handler);
+}
+
+module_init(ir_jvc_decode_init);
+module_exit(ir_jvc_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
+MODULE_DESCRIPTION("JVC IR protocol decoder");