diff options
Diffstat (limited to 'kernel/arch/powerpc/boot/uartlite.c')
-rw-r--r-- | kernel/arch/powerpc/boot/uartlite.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/boot/uartlite.c b/kernel/arch/powerpc/boot/uartlite.c new file mode 100644 index 000000000..46bed69b4 --- /dev/null +++ b/kernel/arch/powerpc/boot/uartlite.c @@ -0,0 +1,79 @@ +/* + * Xilinx UARTLITE bootloader driver + * + * Copyright (C) 2007 Secret Lab Technologies Ltd. + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ + +#include <stdarg.h> +#include <stddef.h> +#include "types.h" +#include "string.h" +#include "stdio.h" +#include "io.h" +#include "ops.h" + +#define ULITE_RX 0x00 +#define ULITE_TX 0x04 +#define ULITE_STATUS 0x08 +#define ULITE_CONTROL 0x0c + +#define ULITE_STATUS_RXVALID 0x01 +#define ULITE_STATUS_TXFULL 0x08 + +#define ULITE_CONTROL_RST_RX 0x02 + +static void * reg_base; + +static int uartlite_open(void) +{ + /* Clear the RX FIFO */ + out_be32(reg_base + ULITE_CONTROL, ULITE_CONTROL_RST_RX); + return 0; +} + +static void uartlite_putc(unsigned char c) +{ + u32 reg = ULITE_STATUS_TXFULL; + while (reg & ULITE_STATUS_TXFULL) /* spin on TXFULL bit */ + reg = in_be32(reg_base + ULITE_STATUS); + out_be32(reg_base + ULITE_TX, c); +} + +static unsigned char uartlite_getc(void) +{ + u32 reg = 0; + while (!(reg & ULITE_STATUS_RXVALID)) /* spin waiting for RXVALID bit */ + reg = in_be32(reg_base + ULITE_STATUS); + return in_be32(reg_base + ULITE_RX); +} + +static u8 uartlite_tstc(void) +{ + u32 reg = in_be32(reg_base + ULITE_STATUS); + return reg & ULITE_STATUS_RXVALID; +} + +int uartlite_console_init(void *devp, struct serial_console_data *scdp) +{ + int n; + unsigned long reg_phys; + + n = getprop(devp, "virtual-reg", ®_base, sizeof(reg_base)); + if (n != sizeof(reg_base)) { + if (!dt_xlate_reg(devp, 0, ®_phys, NULL)) + return -1; + + reg_base = (void *)reg_phys; + } + + scdp->open = uartlite_open; + scdp->putc = uartlite_putc; + scdp->getc = uartlite_getc; + scdp->tstc = uartlite_tstc; + scdp->close = NULL; + return 0; +} |