[media] rc: img-ir: add NEC decoder module

Add an img-ir module for decoding the NEC and extended NEC infrared
protocols.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

4 files changed, 161 insertions, 0 deletions

diff --git a/drivers/media/rc/img-ir/Kconfig b/drivers/media/rc/img-ir/Kconfig
index 60eaba6a0843..28498a294daa 100644
--- a/drivers/media/rc/img-ir/Kconfig
+++ b/drivers/media/rc/img-ir/Kconfig
@@ -24,3 +24,10 @@ config IR_IMG_HW
            signals in hardware. This is more reliable, consumes less processing
            power since only a single interrupt is received for each scancode,
            and allows an IR scancode to be used as a wake event.
+
+config IR_IMG_NEC
+        bool "NEC protocol support"
+        depends on IR_IMG_HW
+        help
+           Say Y here to enable support for the NEC, extended NEC, and 32-bit
+           NEC protocols in the ImgTec infrared decoder block.
diff --git a/drivers/media/rc/img-ir/Makefile b/drivers/media/rc/img-ir/Makefile
index 4ef86edec873..c4091973b35d 100644
--- a/drivers/media/rc/img-ir/Makefile
+++ b/drivers/media/rc/img-ir/Makefile
@@ -1,6 +1,7 @@
 img-ir-y                        := img-ir-core.o
 img-ir-$(CONFIG_IR_IMG_RAW)     += img-ir-raw.o
 img-ir-$(CONFIG_IR_IMG_HW)      += img-ir-hw.o
+img-ir-$(CONFIG_IR_IMG_NEC)     += img-ir-nec.o
 img-ir-objs                     := $(img-ir-y)
 
 obj-$(CONFIG_IR_IMG)            += img-ir.o
diff --git a/drivers/media/rc/img-ir/img-ir-hw.c b/drivers/media/rc/img-ir/img-ir-hw.c
index 21c8bbca8821..139f2c70e382 100644
--- a/drivers/media/rc/img-ir/img-ir-hw.c
+++ b/drivers/media/rc/img-ir/img-ir-hw.c
@@ -20,8 +20,13 @@
 /* Decoders lock (only modified to preprocess them) */
 static DEFINE_SPINLOCK(img_ir_decoders_lock);
 
+extern struct img_ir_decoder img_ir_nec;
+
 static bool img_ir_decoders_preprocessed;
 static struct img_ir_decoder *img_ir_decoders[] = {
+#ifdef CONFIG_IR_IMG_NEC
+        &img_ir_nec,
+#endif
         NULL
 };
 
diff --git a/drivers/media/rc/img-ir/img-ir-nec.c b/drivers/media/rc/img-ir/img-ir-nec.c
new file mode 100644
index 000000000000..e7a731bc3a9b
--- /dev/null
+++ b/drivers/media/rc/img-ir/img-ir-nec.c
@@ -0,0 +1,148 @@
+/*
+ * ImgTec IR Decoder setup for NEC protocol.
+ *
+ * Copyright 2010-2014 Imagination Technologies Ltd.
+ */
+
+#include "img-ir-hw.h"
+
+/* Convert NEC data to a scancode */
+static int img_ir_nec_scancode(int len, u64 raw, int *scancode, u64 protocols)
+{
+        unsigned int addr, addr_inv, data, data_inv;
+        /* a repeat code has no data */
+        if (!len)
+                return IMG_IR_REPEATCODE;
+        if (len != 32)
+                return -EINVAL;
+        /* raw encoding: ddDDaaAA */
+        addr     = (raw >>  0) & 0xff;
+        addr_inv = (raw >>  8) & 0xff;
+        data     = (raw >> 16) & 0xff;
+        data_inv = (raw >> 24) & 0xff;
+        if ((data_inv ^ data) != 0xff) {
+                /* 32-bit NEC (used by Apple and TiVo remotes) */
+                /* scan encoding: aaAAddDD */
+                *scancode = addr_inv << 24 |
+                            addr     << 16 |
+                            data_inv <<  8 |
+                            data;
+        } else if ((addr_inv ^ addr) != 0xff) {
+                /* Extended NEC */
+                /* scan encoding: AAaaDD */
+                *scancode = addr     << 16 |
+                            addr_inv <<  8 |
+                            data;
+        } else {
+                /* Normal NEC */
+                /* scan encoding: AADD */
+                *scancode = addr << 8 |
+                            data;
+        }
+        return IMG_IR_SCANCODE;
+}
+
+/* Convert NEC scancode to NEC data filter */
+static int img_ir_nec_filter(const struct rc_scancode_filter *in,
+                             struct img_ir_filter *out, u64 protocols)
+{
+        unsigned int addr, addr_inv, data, data_inv;
+        unsigned int addr_m, addr_inv_m, data_m, data_inv_m;
+
+        data       = in->data & 0xff;
+        data_m     = in->mask & 0xff;
+
+        if ((in->data | in->mask) & 0xff000000) {
+                /* 32-bit NEC (used by Apple and TiVo remotes) */
+                /* scan encoding: aaAAddDD */
+                addr_inv   = (in->data >> 24) & 0xff;
+                addr_inv_m = (in->mask >> 24) & 0xff;
+                addr       = (in->data >> 16) & 0xff;
+                addr_m     = (in->mask >> 16) & 0xff;
+                data_inv   = (in->data >>  8) & 0xff;
+                data_inv_m = (in->mask >>  8) & 0xff;
+        } else if ((in->data | in->mask) & 0x00ff0000) {
+                /* Extended NEC */
+                /* scan encoding AAaaDD */
+                addr       = (in->data >> 16) & 0xff;
+                addr_m     = (in->mask >> 16) & 0xff;
+                addr_inv   = (in->data >>  8) & 0xff;
+                addr_inv_m = (in->mask >>  8) & 0xff;
+                data_inv   = data ^ 0xff;
+                data_inv_m = data_m;
+        } else {
+                /* Normal NEC */
+                /* scan encoding: AADD */
+                addr       = (in->data >>  8) & 0xff;
+                addr_m     = (in->mask >>  8) & 0xff;
+                addr_inv   = addr ^ 0xff;
+                addr_inv_m = addr_m;
+                data_inv   = data ^ 0xff;
+                data_inv_m = data_m;
+        }
+
+        /* raw encoding: ddDDaaAA */
+        out->data = data_inv << 24 |
+                    data     << 16 |
+                    addr_inv <<  8 |
+                    addr;
+        out->mask = data_inv_m << 24 |
+                    data_m     << 16 |
+                    addr_inv_m <<  8 |
+                    addr_m;
+        return 0;
+}
+
+/*
+ * NEC decoder
+ * See also http://www.sbprojects.com/knowledge/ir/nec.php
+ *        http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol
+ */
+struct img_ir_decoder img_ir_nec = {
+        .type = RC_BIT_NEC,
+        .control = {
+                .decoden = 1,
+                .code_type = IMG_IR_CODETYPE_PULSEDIST,
+        },
+        /* main timings */
+        .unit = 562500, /* 562.5 us */
+        .timings = {
+                /* leader symbol */
+                .ldr = {
+                        .pulse = { 16   /* 9ms */ },
+                        .space = { 8    /* 4.5ms */ },
+                },
+                /* 0 symbol */
+                .s00 = {
+                        .pulse = { 1    /* 562.5 us */ },
+                        .space = { 1    /* 562.5 us */ },
+                },
+                /* 1 symbol */
+                .s01 = {
+                        .pulse = { 1    /* 562.5 us */ },
+                        .space = { 3    /* 1687.5 us */ },
+                },
+                /* free time */
+                .ft = {
+                        .minlen = 32,
+                        .maxlen = 32,
+                        .ft_min = 10,   /* 5.625 ms */
+                },
+        },
+        /* repeat codes */
+        .repeat = 108,                  /* 108 ms */
+        .rtimings = {
+                /* leader symbol */
+                .ldr = {
+                        .space = { 4    /* 2.25 ms */ },
+                },
+                /* free time */
+                .ft = {
+                        .minlen = 0,    /* repeat code has no data */
+                        .maxlen = 0,
+                },
+        },
+        /* scancode logic */
+        .scancode = img_ir_nec_scancode,
+        .filter = img_ir_nec_filter,
+};