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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/powerpc/boot/ns16550.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
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.c | 84 |
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 **)®_base, 1) < 1) { + printf("virt reg parse fail...\r\n"); + return -1; + } + + n = getprop(devp, "reg-offset", ®_offset, sizeof(reg_offset)); + if (n == sizeof(reg_offset)) + reg_base += be32_to_cpu(reg_offset); + + n = getprop(devp, "reg-shift", ®_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; +} |