[media] em28xx: add support for RC6 mode 0 on devices that support it

Newer em28xx chipsets (em2874 and upper) are capable of supporting
RC6 codes, on both mode 0 (command mode, 16 bits payload size, similar
to RC5, also called "Philips mode") and mode 6a (OEM command mode,
with offers a few alternatives with regards to the payload size).
I don't have any mode 6a control ATM to test it, so, I opted to add
support only to mode 0.
After this patch, adding support to mode 6a should not be hard.
Tested with a Philips television remote controller.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 76 insertions, 17 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c
index 507370c5217d..3899ea823336 100644
--- a/drivers/media/usb/em28xx/em28xx-input.c
+++ b/drivers/media/usb/em28xx/em28xx-input.c
@@ -285,6 +285,9 @@ static int em2874_polling_getkey(struct em28xx_IR *ir,
                 else                                    /* Normal NEC */
                         poll_result->scancode = msg[1] << 8 | msg[3];
                 break;
+        case RC_BIT_RC6_0:
+                poll_result->scancode = msg[1] << 8 | msg[2];
+                break;
         default:
                 poll_result->scancode = (msg[1] << 24) | (msg[2] << 16) |
                                         (msg[3] << 8)  | msg[4];
@@ -361,15 +364,42 @@ static void em28xx_ir_stop(struct rc_dev *rc)
         cancel_delayed_work_sync(&ir->work);
 }
 
-static int em28xx_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_type)
+static int em2860_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_type)
 {
-        int rc = 0;
         struct em28xx_IR *ir = rc_dev->priv;
         struct em28xx *dev = ir->dev;
-        u8 ir_config = EM2874_IR_RC5;
 
-        /* Adjust xclk based o IR table for RC5/NEC tables */
+        /* Adjust xclk based on IR table for RC5/NEC tables */
+        if (*rc_type & RC_BIT_RC5) {
+                dev->board.xclk |= EM28XX_XCLK_IR_RC5_MODE;
+                ir->full_code = 1;
+                *rc_type = RC_BIT_RC5;
+        } else if (*rc_type & RC_BIT_NEC) {
+                dev->board.xclk &= ~EM28XX_XCLK_IR_RC5_MODE;
+                ir->full_code = 1;
+                *rc_type = RC_BIT_NEC;
+        } else if (*rc_type & RC_BIT_UNKNOWN) {
+                *rc_type = RC_BIT_UNKNOWN;
+        } else {
+                *rc_type = ir->rc_type;
+                return -EINVAL;
+        }
+        ir->get_key = default_polling_getkey;
+        em28xx_write_reg_bits(dev, EM28XX_R0F_XCLK, dev->board.xclk,
+                              EM28XX_XCLK_IR_RC5_MODE);
+
+        ir->rc_type = *rc_type;
 
+        return 0;
+}
+
+static int em2874_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_type)
+{
+        struct em28xx_IR *ir = rc_dev->priv;
+        struct em28xx *dev = ir->dev;
+        u8 ir_config = EM2874_IR_RC5;
+
+        /* Adjust xclk and set type based on IR table for RC5/NEC/RC6 tables */
         if (*rc_type & RC_BIT_RC5) {
                 dev->board.xclk |= EM28XX_XCLK_IR_RC5_MODE;
                 ir->full_code = 1;
@@ -379,33 +409,47 @@ static int em28xx_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_type)
                 ir_config = EM2874_IR_NEC | EM2874_IR_NEC_NO_PARITY;
                 ir->full_code = 1;
                 *rc_type = RC_BIT_NEC;
-        } else if (*rc_type != RC_BIT_UNKNOWN)
-                rc = -EINVAL;
+        } else if (*rc_type & RC_BIT_RC6_0) {
+                dev->board.xclk |= EM28XX_XCLK_IR_RC5_MODE;
+                ir_config = EM2874_IR_RC6_MODE_0;
+                ir->full_code = 1;
+                *rc_type = RC_BIT_RC6_0;
+        } else if (*rc_type & RC_BIT_UNKNOWN) {
+                *rc_type = RC_BIT_UNKNOWN;
+        } else {
+                *rc_type = ir->rc_type;
+                return -EINVAL;
+        }
 
-        ir->rc_type = *rc_type;
+        ir->get_key = em2874_polling_getkey;
+        em28xx_write_regs(dev, EM2874_R50_IR_CONFIG, &ir_config, 1);
 
         em28xx_write_reg_bits(dev, EM28XX_R0F_XCLK, dev->board.xclk,
                               EM28XX_XCLK_IR_RC5_MODE);
 
+        ir->rc_type = *rc_type;
+
+        return 0;
+}
+static int em28xx_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_type)
+{
+        struct em28xx_IR *ir = rc_dev->priv;
+        struct em28xx *dev = ir->dev;
+
         /* Setup the proper handler based on the chip */
         switch (dev->chip_id) {
         case CHIP_ID_EM2860:
         case CHIP_ID_EM2883:
-                ir->get_key = default_polling_getkey;
-                break;
+                return em2860_ir_change_protocol(rc_dev, rc_type);
         case CHIP_ID_EM2884:
         case CHIP_ID_EM2874:
         case CHIP_ID_EM28174:
-                ir->get_key = em2874_polling_getkey;
-                em28xx_write_regs(dev, EM2874_R50_IR_CONFIG, &ir_config, 1);
-                break;
+                return em2874_ir_change_protocol(rc_dev, rc_type);
         default:
                 printk("Unrecognized em28xx chip id 0x%02x: IR not supported\n",
                         dev->chip_id);
-                rc = -EINVAL;
+                return -EINVAL;
         }
-
-        return rc;
 }
 
 static void em28xx_register_i2c_ir(struct em28xx *dev)
@@ -573,6 +617,21 @@ static int em28xx_ir_init(struct em28xx *dev)
         rc->open = em28xx_ir_start;
         rc->close = em28xx_ir_stop;
 
+        switch (dev->chip_id) {
+        case CHIP_ID_EM2860:
+        case CHIP_ID_EM2883:
+                rc->allowed_protos = RC_BIT_RC5 | RC_BIT_NEC;
+                break;
+        case CHIP_ID_EM2884:
+        case CHIP_ID_EM2874:
+        case CHIP_ID_EM28174:
+                rc->allowed_protos = RC_BIT_RC5 | RC_BIT_NEC | RC_BIT_RC6_0;
+                break;
+        default:
+                err = -ENODEV;
+                goto err_out_free;
+        }
+
         /* By default, keep protocol field untouched */
         rc_type = RC_BIT_UNKNOWN;
         err = em28xx_ir_change_protocol(rc, &rc_type);
@@ -615,9 +674,9 @@ static int em28xx_ir_init(struct em28xx *dev)
 
         return 0;
 
- err_out_stop:
+err_out_stop:
         dev->ir = NULL;
- err_out_free:
+err_out_free:
         rc_free_device(rc);
         kfree(ir);
         return err;