improved i2s driver

1 files changed, 17 insertions, 8 deletions

diff --git a/fw/fe310/eos/soc/trap_entry.S b/fw/fe310/eos/soc/trap_entry.S
index 7417254..1d3d1c2 100644
--- a/fw/fe310/eos/soc/trap_entry.S
+++ b/fw/fe310/eos/soc/trap_entry.S
@@ -99,12 +99,11 @@ i2s_handle_sd:
   # store channel bit to x25
   li x18, I2S_CTRL_ADDR_WS
   lw x18, PWM_CFG(x18)
+  # 29th - pwmcmp1ip bit
   li x19, (1 << 29)
   and x25, x18, x19
   srli x25, x25, 29
 
-  bnez x25, i2s_sd_complete
-
   la x27, _eos_i2s_drvr
   lw x26, I2S_FMT(x27)
 
@@ -123,10 +122,12 @@ i2s_abuf_pop:
   lw x21, I2S_ABUF_OFF_ARRAY(x9)
   add x21, x21, x20
   beqz x26, 0f
+  mv x22, x18
   lbu x8, 0(x21)
   addi x18, x18, 1
   j 1f
 0:
+  srli x22, x18, 1
   lb x8, 0(x21)
   lbu x20, 1(x21)
   slli x8, x8, 8
@@ -135,6 +136,13 @@ i2s_abuf_pop:
 1:
   sh x18, I2S_ABUF_OFF_IDXR(x9)
 
+  # check for correct channel if mode is stereo
+  lw x21, I2S_MODE(x27)
+  bnez x21, 2f
+  andi x22, x22, 1
+  xor x22, x22, x25
+  beqz x22, i2s_abuf_pop
+
 2:
   li x21, 0xffff
   sub x18, x19, x18
@@ -194,13 +202,11 @@ i2s_decode:
 3:
 
 i2s_sd_xchg:
-  # li x18, 0xa5a5
-  # mv x8, x18
   # read/write shift reg: x8 -> sr -> x8
   li x18, GPIO_CTRL_ADDR
-  li x19, (0x1 << I2S_PIN_SD_IN)
-  li x20, (0x1 << I2S_PIN_SD_OUT)
-  li x21, (0x1 << I2S_PIN_SR_CK)
+  li x19, (1 << I2S_PIN_SD_IN)
+  li x20, (1 << I2S_PIN_SD_OUT)
+  li x21, (1 << I2S_PIN_SR_CK)
   lw x22, GPIO_OUTPUT_VAL(x18)
 
   lw x9, GPIO_OUTPUT_EN(x18)
@@ -272,6 +278,9 @@ i2s_sd_xchg:
   slli x8, x8, 16
   srai x8, x8, 16
 
+  # skip right channel
+  bnez x25, i2s_sd_complete
+
 i2s_encode:
   beqz x26, i2s_abuf_push
   # aLaw encode -> x8
@@ -352,7 +361,7 @@ i2s_abuf_push:
 
 i2s_sd_complete:
   li x18, GPIO_CTRL_ADDR
-  li x19, (0x1 << I2S_PIN_INT)
+  li x19, (1 << I2S_PIN_INT)
   sw x19, GPIO_FALL_IP(x18)
 
   li x18, I2S_IRQ_SD_ID