[PATCH v2 3/9] escc: introduce escc_soft_reset_chn() for software reset

[Mark Cave-Ayland]

This new software reset function is to be called when the appropriate channel
software reset bit is written to register WR9. Its initial implementation is
the same as the existing escc_reset_chn() function used for device reset.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/char/escc.c | 38 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/hw/char/escc.c b/hw/char/escc.c
index b0d3b92dc1..935ec1aef6 100644
--- a/hw/char/escc.c
+++ b/hw/char/escc.c
@@ -297,6 +297,40 @@ static void escc_reset_chn(ESCCChannelState *s)
     clear_queue(s);
 }
 
+static void escc_soft_reset_chn(ESCCChannelState *s)
+{
+    int i;
+
+    s->reg = 0;
+    for (i = 0; i < ESCC_SERIAL_REGS; i++) {
+        s->rregs[i] = 0;
+        s->wregs[i] = 0;
+    }
+    /* 1X divisor, 1 stop bit, no parity */
+    s->wregs[W_TXCTRL1] = TXCTRL1_1STOP;
+    s->wregs[W_MINTR] = MINTR_RST_ALL;
+    /* Synch mode tx clock = TRxC */
+    s->wregs[W_CLOCK] = CLOCK_TRXC;
+    /* PLL disabled */
+    s->wregs[W_MISC2] = MISC2_PLLDIS;
+    /* Enable most interrupts */
+    s->wregs[W_EXTINT] = EXTINT_DCD | EXTINT_SYNCINT | EXTINT_CTSINT |
+                         EXTINT_TXUNDRN | EXTINT_BRKINT;
+    if (s->disabled) {
+        s->rregs[R_STATUS] = STATUS_TXEMPTY | STATUS_DCD | STATUS_SYNC |
+                             STATUS_CTS | STATUS_TXUNDRN;
+    } else {
+        s->rregs[R_STATUS] = STATUS_TXEMPTY | STATUS_TXUNDRN;
+    }
+    s->rregs[R_SPEC] = SPEC_BITS8 | SPEC_ALLSENT;
+
+    s->rx = s->tx = 0;
+    s->rxint = s->txint = 0;
+    s->rxint_under_svc = s->txint_under_svc = 0;
+    s->e0_mode = s->led_mode = s->caps_lock_mode = s->num_lock_mode = 0;
+    clear_queue(s);
+}
+
 static void escc_reset(DeviceState *d)
 {
     ESCCState *s = ESCC(d);
@@ -547,10 +581,10 @@ static void escc_mem_write(void *opaque, hwaddr addr,
             default:
                 break;
             case MINTR_RST_B:
-                escc_reset_chn(&serial->chn[0]);
+                escc_soft_reset_chn(&serial->chn[0]);
                 return;
             case MINTR_RST_A:
-                escc_reset_chn(&serial->chn[1]);
+                escc_soft_reset_chn(&serial->chn[1]);
                 return;
             case MINTR_RST_ALL:
                 escc_reset(DEVICE(serial));
-- 
2.20.1