diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/tty/hvc/hvc_dcc.c')
-rw-r--r-- | ANDROID_3.4.5/drivers/tty/hvc/hvc_dcc.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/drivers/tty/hvc/hvc_dcc.c b/ANDROID_3.4.5/drivers/tty/hvc/hvc_dcc.c new file mode 100644 index 00000000..44fbebab --- /dev/null +++ b/ANDROID_3.4.5/drivers/tty/hvc/hvc_dcc.c @@ -0,0 +1,106 @@ +/* Copyright (c) 2010, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only 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., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#include <asm/processor.h> + +#include "hvc_console.h" + +/* DCC Status Bits */ +#define DCC_STATUS_RX (1 << 30) +#define DCC_STATUS_TX (1 << 29) + +static inline u32 __dcc_getstatus(void) +{ + u32 __ret; + asm volatile("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg" + : "=r" (__ret) : : "cc"); + + return __ret; +} + + +static inline char __dcc_getchar(void) +{ + char __c; + + asm volatile("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg" + : "=r" (__c)); + isb(); + + return __c; +} + +static inline void __dcc_putchar(char c) +{ + asm volatile("mcr p14, 0, %0, c0, c5, 0 @ write a char" + : /* no output register */ + : "r" (c)); + isb(); +} + +static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count) +{ + int i; + + for (i = 0; i < count; i++) { + while (__dcc_getstatus() & DCC_STATUS_TX) + cpu_relax(); + + __dcc_putchar(buf[i]); + } + + return count; +} + +static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count) +{ + int i; + + for (i = 0; i < count; ++i) + if (__dcc_getstatus() & DCC_STATUS_RX) + buf[i] = __dcc_getchar(); + else + break; + + return i; +} + +static const struct hv_ops hvc_dcc_get_put_ops = { + .get_chars = hvc_dcc_get_chars, + .put_chars = hvc_dcc_put_chars, +}; + +static int __init hvc_dcc_console_init(void) +{ + hvc_instantiate(0, 0, &hvc_dcc_get_put_ops); + return 0; +} +console_initcall(hvc_dcc_console_init); + +static int __init hvc_dcc_init(void) +{ + hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128); + return 0; +} +device_initcall(hvc_dcc_init); |