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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/powerpc/boot/ns16550.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/boot/ns16550.c')
-rw-r--r--arch/powerpc/boot/ns16550.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/powerpc/boot/ns16550.c b/arch/powerpc/boot/ns16550.c
new file mode 100644
index 000000000..f16d2be1d
--- /dev/null
+++ b/arch/powerpc/boot/ns16550.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 16550 serial console support.
+ *
+ * Original copied from <file:arch/ppc/boot/common/ns16550.c>
+ * (which had no copyright)
+ * Modifications: 2006 (c) MontaVista Software, Inc.
+ *
+ * Modified by: Mark A. Greer <mgreer@mvista.com>
+ */
+#include <stdarg.h>
+#include <stddef.h>
+#include "types.h"
+#include "string.h"
+#include "stdio.h"
+#include "io.h"
+#include "ops.h"
+#include "of.h"
+
+#define UART_DLL 0 /* Out: Divisor Latch Low */
+#define UART_DLM 1 /* Out: Divisor Latch High */
+#define UART_FCR 2 /* Out: FIFO Control Register */
+#define UART_LCR 3 /* Out: Line Control Register */
+#define UART_MCR 4 /* Out: Modem Control Register */
+#define UART_LSR 5 /* In: Line Status Register */
+#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
+#define UART_LSR_DR 0x01 /* Receiver data ready */
+#define UART_MSR 6 /* In: Modem Status Register */
+#define UART_SCR 7 /* I/O: Scratch Register */
+
+static unsigned char *reg_base;
+static u32 reg_shift;
+
+static int ns16550_open(void)
+{
+ out_8(reg_base + (UART_FCR << reg_shift), 0x06);
+ return 0;
+}
+
+static void ns16550_putc(unsigned char c)
+{
+ while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_THRE) == 0);
+ out_8(reg_base, c);
+}
+
+static unsigned char ns16550_getc(void)
+{
+ while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) == 0);
+ return in_8(reg_base);
+}
+
+static u8 ns16550_tstc(void)
+{
+ return ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) != 0);
+}
+
+int ns16550_console_init(void *devp, struct serial_console_data *scdp)
+{
+ int n;
+ u32 reg_offset;
+
+ if (dt_get_virtual_reg(devp, (void **)&reg_base, 1) < 1) {
+ printf("virt reg parse fail...\r\n");
+ return -1;
+ }
+
+ n = getprop(devp, "reg-offset", &reg_offset, sizeof(reg_offset));
+ if (n == sizeof(reg_offset))
+ reg_base += be32_to_cpu(reg_offset);
+
+ n = getprop(devp, "reg-shift", &reg_shift, sizeof(reg_shift));
+ if (n != sizeof(reg_shift))
+ reg_shift = 0;
+ else
+ reg_shift = be32_to_cpu(reg_shift);
+
+ scdp->open = ns16550_open;
+ scdp->putc = ns16550_putc;
+ scdp->getc = ns16550_getc;
+ scdp->tstc = ns16550_tstc;
+ scdp->close = NULL;
+
+ return 0;
+}