V4L/DVB (9584): Support different GPIO/GPO registers for newer devices

Empia moved the location of the GPIO/GPO registers in newer devices.  Add the
ability to specify the relocated registers (including caching of register
contents).

Thanks for Ray Lu from Empia for providing the em2874 datasheet.

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index 90389270389b..791ab2cc7d8f 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -1312,11 +1312,13 @@ void em28xx_pre_card_setup(struct em28xx *dev)
 {
         int rc;
 
-        rc = em28xx_read_reg(dev, EM2880_R04_GPO);
-        if (rc >= 0)
-                dev->reg_gpo = rc;
+        /* Set the default GPO/GPIO for legacy devices */
+        dev->reg_gpo_num = EM2880_R04_GPO;
+        dev->reg_gpio_num = EM28XX_R08_GPIO;
 
         dev->wait_after_write = 5;
+
+        /* Based on the Chip ID, set the device configuration */
         rc = em28xx_read_reg(dev, EM28XX_R0A_CHIPID);
         if (rc > 0) {
                 dev->chip_id = rc;
@@ -1326,6 +1328,7 @@ void em28xx_pre_card_setup(struct em28xx *dev)
                         break;
                 case CHIP_ID_EM2874:
                         em28xx_info("chip ID is em2874\n");
+                        dev->reg_gpio_num = EM2874_R80_GPIO;
                         dev->wait_after_write = 0;
                         break;
                 case CHIP_ID_EM2883:
@@ -1336,6 +1339,12 @@ void em28xx_pre_card_setup(struct em28xx *dev)
                         em28xx_info("em28xx chip ID = %d\n", rc);
                 }
         }
+
+        /* Prepopulate cached GPO register content */
+        rc = em28xx_read_reg(dev, dev->reg_gpo_num);
+        if (rc >= 0)
+                dev->reg_gpo = rc;
+
         em28xx_set_model(dev);
 
         /* request some modules */