[src/trunk]: src/sys/arch/evbsh3/nextvod Implement cngetc to be able to talk ...

[uwe <uwe%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/dd2924374975
branches:  trunk
changeset: 1012029:dd2924374975
user:      uwe <uwe%NetBSD.org@localhost>
date:      Mon Jul 20 01:06:33 2020 +0000

description:
Implement cngetc to be able to talk to DDB.

diffstat:

 sys/arch/evbsh3/nextvod/stasc.c |  30 ++++++++++++++++++++++++------
 1 files changed, 24 insertions(+), 6 deletions(-)

diffs (70 lines):

diff -r 00569a21c9cf -r dd2924374975 sys/arch/evbsh3/nextvod/stasc.c
--- a/sys/arch/evbsh3/nextvod/stasc.c   Sun Jul 19 23:44:36 2020 +0000
+++ b/sys/arch/evbsh3/nextvod/stasc.c   Mon Jul 20 01:06:33 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: stasc.c,v 1.1 2020/07/19 23:44:36 uwe Exp $ */
+/* $NetBSD: stasc.c,v 1.2 2020/07/20 01:06:33 uwe Exp $ */
 /*
  * Copyright (c) 2020 Valery Ushakov
  * All rights reserved.
@@ -28,7 +28,7 @@
  * STMicroelectronics ST40 Asynchronous Serial Controller
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: stasc.c,v 1.1 2020/07/19 23:44:36 uwe Exp $");
+__KERNEL_RCSID(0, "$NetBSD: stasc.c,v 1.2 2020/07/20 01:06:33 uwe Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -54,6 +54,7 @@
 #define ASC_RETRIES_OFFSET     0x28
 
 #define ASC_TX_BUFF    (*(volatile uint32_t *)(STM_ASC_BASE + ASC_TX_BUFF_OFFSET))
+#define ASC_RX_BUFF    (*(volatile uint32_t *)(STM_ASC_BASE + ASC_RX_BUFF_OFFSET))
 #define ASC_INT_EN     (*(volatile uint32_t *)(STM_ASC_BASE + ASC_INT_EN_OFFSET))
 #define ASC_INT_STA    (*(volatile uint32_t *)(STM_ASC_BASE + ASC_INT_STA_OFFSET))
 
@@ -183,22 +184,39 @@
 int
 stasc_cngetc(dev_t dev)
 {
-       return -1;
+       int s = splserial();
+       uint32_t status;
+       int c;
+
+       /* don't block if Rx buffer is empty */
+       status = ASC_INT_STA;
+       if (!ISSET(status, ASC_INT_STA_RBF)) {
+               splx(s);
+               return -1;
+       }
+
+       /* can read the character now */
+       c = ASC_RX_BUFF;
+       splx(s);
+       return (unsigned char)c;
 }
 
 
 void
 stasc_cnputc(dev_t dev, int c)
 {
-       uint32_t status;
+       int s = splserial();
+       uint32_t timo, status;
 
-       /* wait for Tx FULL to become zero */
+       /* wait for Tx Full to become clear */
+       timo = 150000;
        do {
                status = ASC_INT_STA;
-       } while ((status & ASC_INT_STA_TF) != 0);
+       } while (ISSET(status, ASC_INT_STA_TF) && --timo);
 
        /* can write the character now */
        ASC_TX_BUFF = c;
+       splx(s);
 }