[PATCH] ppc64: very basic desktop g5 sound support

This patch hacks the current PowerMac Alsa driver to add some basic support
of analog sound output to some desktop G5s.  It has severe limitations
though:

 - Only 44100Khz 16 bits
 - Only work on G5 models using a TAS3004 analog code, that is early
   single CPU desktops and all dual CPU desktops at this date, but none
   of the more recent ones like iMac G5.
 - It does analog only, no digital/SPDIF support at all, no native
   AC3 support

Better support would require a complete rewrite of the driver (which I am
working on, but don't hold your breath), to properly support the diversity
of apple sound HW setup, including dual codecs, several i2s busses, all the
new codecs used in the new machines, proper clock switching with digital,
etc etc etc...

This patch applies on top of the other PowerMac sound patches I posted in
the past couple of days (new powerbook support and sleep fixes).  

Note: This is a FAQ entry for PowerMac sound support with TI codecs: They
have a feature called "DRC" which is automatically enabled for the internal
speaker (at least when auto mute control is enabled) which will cause your
sound to fade out to nothing after half a second of playback if you don't
set a proper "DRC Range" in the mixer.  So if you have a problem like that,
check alsamixer and raise your DRC Range to something reasonable.

Note2: This patch will also add auto-mute of the speaker when line-out jack
is used on some earlier desktop G4s (and on the G5) in addition to the
headphone jack.  If that behaviour isn't what you want, just disable
auto-muting and use the manual mute controls in alsamixer.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 29 insertions, 4 deletions

diff --git a/arch/ppc/platforms/pmac_feature.c b/arch/ppc/platforms/pmac_feature.c
index 24b42fd9e014..46cbf36722db 100644
--- a/arch/ppc/platforms/pmac_feature.c
+++ b/arch/ppc/platforms/pmac_feature.c
@@ -74,8 +74,7 @@ static DEFINE_SPINLOCK(feature_lock  __pmacdata);
  */
 struct macio_chip macio_chips[MAX_MACIO_CHIPS]  __pmacdata;
 
-struct macio_chip* __pmac
-macio_find(struct device_node* child, int type)
+struct macio_chip* __pmac macio_find(struct device_node* child, int type)
 {
         while(child) {
                 int     i;
@@ -88,6 +87,7 @@ macio_find(struct device_node* child, int type)
         }
         return NULL;
 }
+EXPORT_SYMBOL_GPL(macio_find);
 
 static const char* macio_names[] __pmacdata =
 {
diff --git a/arch/ppc64/kernel/pmac_feature.c b/arch/ppc64/kernel/pmac_feature.c
index 086abc1bcca1..98ed2bccab1a 100644
--- a/arch/ppc64/kernel/pmac_feature.c
+++ b/arch/ppc64/kernel/pmac_feature.c
@@ -64,8 +64,7 @@ static DEFINE_SPINLOCK(feature_lock  __pmacdata);
  */
 struct macio_chip macio_chips[MAX_MACIO_CHIPS]  __pmacdata;
 
-struct macio_chip* __pmac
-macio_find(struct device_node* child, int type)
+struct macio_chip* __pmac macio_find(struct device_node* child, int type)
 {
         while(child) {
                 int     i;
@@ -78,6 +77,7 @@ macio_find(struct device_node* child, int type)
         }
         return NULL;
 }
+EXPORT_SYMBOL_GPL(macio_find);
 
 static const char* macio_names[] __pmacdata =
 {
@@ -250,6 +250,30 @@ static long __pmac g5_eth_phy_reset(struct device_node* node, long param, long v
         return 0;
 }
 
+static long __pmac g5_i2s_enable(struct device_node *node, long param, long value)
+{
+        /* Very crude implementation for now */
+        struct macio_chip* macio = &macio_chips[0];
+        unsigned long flags;
+
+        if (value == 0)
+                return 0; /* don't disable yet */
+
+        LOCK(flags);
+        MACIO_BIS(KEYLARGO_FCR3, KL3_CLK45_ENABLE | KL3_CLK49_ENABLE |
+                  KL3_I2S0_CLK18_ENABLE);
+        udelay(10);
+        MACIO_BIS(KEYLARGO_FCR1, K2_FCR1_I2S0_CELL_ENABLE |
+                  K2_FCR1_I2S0_CLK_ENABLE_BIT | K2_FCR1_I2S0_ENABLE);
+        udelay(10);
+        MACIO_BIC(KEYLARGO_FCR1, K2_FCR1_I2S0_RESET);
+        UNLOCK(flags);
+        udelay(10);
+
+        return 0;
+}
+
+
 #ifdef CONFIG_SMP
 static long __pmac g5_reset_cpu(struct device_node* node, long param, long value)
 {
@@ -337,6 +361,7 @@ static struct feature_table_entry g5_features[]  __pmacdata = {
         { PMAC_FTR_READ_GPIO,           g5_read_gpio },
         { PMAC_FTR_WRITE_GPIO,          g5_write_gpio },
         { PMAC_FTR_GMAC_PHY_RESET,      g5_eth_phy_reset },
+        { PMAC_FTR_SOUND_CHIP_ENABLE,   g5_i2s_enable },
 #ifdef CONFIG_SMP
         { PMAC_FTR_RESET_CPU,           g5_reset_cpu },
 #endif /* CONFIG_SMP */