diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 12854ef..b0ff5fa 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -1,5 +1,9 @@ menu "serial drivers " +config DRIVER_SERIAL_ARM_DCC + depends on ARM + bool "ARM Debug Communications Channel (DCC) serial driver" + config DRIVER_SERIAL_IMX depends on ARCH_IMX default y diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 3bc965c..8ab680d 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -5,6 +5,7 @@ # serial_pl010.o # serial_pl011.o # serial_xuartlite.o +obj-$(CONFIG_DRIVER_SERIAL_ARM_DCC) += arm_dcc.o obj-$(CONFIG_DRIVER_SERIAL_IMX) += serial_imx.o obj-$(CONFIG_DRIVER_SERIAL_ATMEL) += atmel.o obj-$(CONFIG_DRIVER_SERIAL_NETX) += serial_netx.o diff --git a/drivers/serial/arm_dcc.c b/drivers/serial/arm_dcc.c new file mode 100644 index 0000000..151730b --- /dev/null +++ b/drivers/serial/arm_dcc.c @@ -0,0 +1,169 @@ +/* + * Copyright (C) 2004-2007 ARM Limited. + * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * As a special exception, if other files instantiate templates or use macros + * or inline functions from this file, or you compile this file and link it + * with other works to produce a work based on this file, this file does not + * by itself cause the resulting work to be covered by the GNU General Public + * License. However the source code for this file must still be made available + * in accordance with section (3) of the GNU General Public License. + + * This exception does not invalidate any other reasons why a work based on + * this file might be covered by the GNU General Public License. + */ + +#include +#include +#include + +#if defined(CONFIG_CPU_V6) +/* + * ARMV6 + */ +#define DCC_RBIT (1 << 30) +#define DCC_WBIT (1 << 29) + +#define write_dcc(x) \ + __asm__ volatile ("mcr p14, 0, %0, c0, c5, 0\n" : : "r" (x)) + +#define read_dcc(x) \ + __asm__ volatile ("mrc p14, 0, %0, c0, c5, 0\n" : "=r" (x)) + +#define status_dcc(x) \ + __asm__ volatile ("mrc p14, 0, %0, c0, c1, 0\n" : "=r" (x)) + +#elif defined(CONFIG_CPU_XSCALE) +/* + * XSCALE + */ +#define DCC_RBIT (1 << 31) +#define DCC_WBIT (1 << 28) + +#define write_dcc(x) \ + __asm__ volatile ("mcr p14, 0, %0, c8, c0, 0\n" : : "r" (x)) + +#define read_dcc(x) \ + __asm__ volatile ("mrc p14, 0, %0, c9, c0, 0\n" : "=r" (x)) + +#define status_dcc(x) \ + __asm__ volatile ("mrc p14, 0, %0, c14, c0, 0\n" : "=r" (x)) + +#else +#define DCC_RBIT (1 << 0) +#define DCC_WBIT (1 << 1) + +#define write_dcc(x) \ + __asm__ volatile ("mcr p14, 0, %0, c1, c0, 0\n" : : "r" (x)) + +#define read_dcc(x) \ + __asm__ volatile ("mrc p14, 0, %0, c1, c0, 0\n" : "=r" (x)) + +#define status_dcc(x) \ + __asm__ volatile ("mrc p14, 0, %0, c0, c0, 0\n" : "=r" (x)) + +#endif + +#define can_read_dcc(x) do { \ + status_dcc(x); \ + x &= DCC_RBIT; \ + } while (0); + +#define can_write_dcc(x) do { \ + status_dcc(x); \ + x &= DCC_WBIT; \ + x = (x == 0); \ + } while (0); + +#define TIMEOUT_COUNT 0x4000000 + +static int arm_dcc_getc(struct console_device *cdev) +{ + int c; + register unsigned int reg; + + do { + can_read_dcc(reg); + } while (!reg); + read_dcc(c); + + return c; +} + +static void arm_dcc_putc(struct console_device *cdev, char c) +{ + register unsigned int reg; + unsigned int timeout_count = TIMEOUT_COUNT; + + while (--timeout_count) { + can_write_dcc(reg); + if (reg) + break; + } + if (timeout_count == 0) + return; + else + write_dcc(c); +} + +static int arm_dcc_tstc(struct console_device *cdev) +{ + register unsigned int reg; + + can_read_dcc(reg); + + return reg; +} + +static struct console_device arm_dcc_dev; + +static int arm_dcc_probe(struct device_d *dev) +{ + struct console_device *cdev; + + cdev = &arm_dcc_dev; + dev->type_data = cdev; + cdev->dev = dev; + cdev->f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR; + cdev->tstc = arm_dcc_tstc; + cdev->putc = arm_dcc_putc; + cdev->getc = arm_dcc_getc; + + /* Enable UART */ + + console_register(cdev); + + return 0; +} + +static struct driver_d arm_dcc_driver = { + .name = "arm_dcc", + .probe = arm_dcc_probe, +}; + +static struct device_d arm_dcc_device = { + .name = "arm_dcc", + .size = 4096, +}; + +static int arm_dcc_init(void) +{ + register_device(&arm_dcc_device); + register_driver(&arm_dcc_driver); + return 0; +} + +console_initcall(arm_dcc_init);