Some STK1160-based devices use the chip's internal 8-bit ADC. This is
configured through a strap
pin. The value of this and other pins can be read through the POSVA register.
If the internal
ADC is used, or if audio is disabled altogether, there's no point trying to
setup the AC97 codec.
Signed-off-by: Marcel Hasler <mahas...@gmail.com>
---
drivers/media/usb/stk1160/stk1160-ac97.c | 26 ++++++++++++++++++++++++++
drivers/media/usb/stk1160/stk1160-core.c | 3 +--
drivers/media/usb/stk1160/stk1160-reg.h | 8 ++++++++
3 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/stk1160/stk1160-ac97.c
b/drivers/media/usb/stk1160/stk1160-ac97.c
index 63ade1b..95648ac 100644
--- a/drivers/media/usb/stk1160/stk1160-ac97.c
+++ b/drivers/media/usb/stk1160/stk1160-ac97.c
@@ -93,8 +93,34 @@ void stk1160_ac97_dump_regs(struct stk1160 *dev)
}
#endif
+int stk1160_has_audio(struct stk1160 *dev)
+{
+ u8 value;
+
+ stk1160_read_reg(dev, STK1160_POSV_L, &value);
+ return !(value & STK1160_POSV_L_ACDOUT);
+}
+
+int stk1160_has_ac97(struct stk1160 *dev)
+{
+ u8 value;
+
+ stk1160_read_reg(dev, STK1160_POSV_L, &value);
+ return !(value & STK1160_POSV_L_ACSYNC);
+}
+
void stk1160_ac97_setup(struct stk1160 *dev)
{
+ if (!stk1160_has_audio(dev)) {
+ stk1160_info("Device doesn't support audio, skipping AC97
setup.");
+ return;
+ }
+
+ if (!stk1160_has_ac97(dev)) {
+ stk1160_info("Device uses internal 8-bit ADC, skipping AC97
setup.");
+ return;
+ }
+
/* Two-step reset AC97 interface and hardware codec */
stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x94);
stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8c);
diff --git a/drivers/media/usb/stk1160/stk1160-core.c
b/drivers/media/usb/stk1160/stk1160-core.c
index f3c9b8a..c86eb61 100644
--- a/drivers/media/usb/stk1160/stk1160-core.c
+++ b/drivers/media/usb/stk1160/stk1160-core.c
@@ -20,8 +20,7 @@
*
* TODO:
*
- * 1. (Try to) detect if we must register ac97 mixer
- * 2. Support stream at lower speed: lower frame rate or lower frame size.
+ * 1. Support stream at lower speed: lower frame rate or lower frame size.
*
*/
diff --git a/drivers/media/usb/stk1160/stk1160-reg.h
b/drivers/media/usb/stk1160/stk1160-reg.h
index 81ff3a1..296a9e7 100644
--- a/drivers/media/usb/stk1160/stk1160-reg.h
+++ b/drivers/media/usb/stk1160/stk1160-reg.h
@@ -26,6 +26,14 @@
/* Remote Wakup Control */
#define STK1160_RMCTL 0x00c
+/* Power-on Strapping Data */
+#define STK1160_POSVA 0x010
+#define STK1160_POSV_L 0x010
+#define STK1160_POSV_M 0x011
+#define STK1160_POSV_H 0x012
+#define STK1160_POSV_L_ACDOUT BIT(3)
+#define STK1160_POSV_L_ACSYNC BIT(2)
+
/*
* Decoder Control Register:
* This byte controls capture start/stop
--
2.10.2
--
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