From f7511d5f66f01fc451747b24e79f3ada7a3af9af Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Wed, 30 Apr 2008 00:54:51 -0700 Subject: Basic braille screen reader support This adds a minimalistic braille screen reader support. This is meant to be used by blind people e.g. on boot failures or when / cannot be mounted etc and thus the userland screen readers can not work. [akpm@linux-foundation.org: fix exports] Signed-off-by: Samuel Thibault Cc: Jiri Kosina Cc: Dmitry Torokhov Acked-by: Alan Cox Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/accessibility/Kconfig | 23 ++ drivers/accessibility/Makefile | 1 + drivers/accessibility/braille/Makefile | 1 + drivers/accessibility/braille/braille_console.c | 397 ++++++++++++++++++++++++ 4 files changed, 422 insertions(+) create mode 100644 drivers/accessibility/Kconfig create mode 100644 drivers/accessibility/Makefile create mode 100644 drivers/accessibility/braille/Makefile create mode 100644 drivers/accessibility/braille/braille_console.c (limited to 'drivers/accessibility') diff --git a/drivers/accessibility/Kconfig b/drivers/accessibility/Kconfig new file mode 100644 index 00000000000..1264c4b9809 --- /dev/null +++ b/drivers/accessibility/Kconfig @@ -0,0 +1,23 @@ +menuconfig ACCESSIBILITY + bool "Accessibility support" + ---help--- + Enable a submenu where accessibility items may be enabled. + + If unsure, say N. + +if ACCESSIBILITY +config A11Y_BRAILLE_CONSOLE + bool "Console on braille device" + depends on VT + depends on SERIAL_CORE_CONSOLE + ---help--- + Enables console output on a braille device connected to a 8250 + serial port. For now only the VisioBraille device is supported. + + To actually enable it, you need to pass option + console=brl,ttyS0 + to the kernel. Options are the same as for serial console. + + If unsure, say N. + +endif # ACCESSIBILITY diff --git a/drivers/accessibility/Makefile b/drivers/accessibility/Makefile new file mode 100644 index 00000000000..72b01a46546 --- /dev/null +++ b/drivers/accessibility/Makefile @@ -0,0 +1 @@ +obj-y += braille/ diff --git a/drivers/accessibility/braille/Makefile b/drivers/accessibility/braille/Makefile new file mode 100644 index 00000000000..2e9f16c9134 --- /dev/null +++ b/drivers/accessibility/braille/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_A11Y_BRAILLE_CONSOLE) += braille_console.o diff --git a/drivers/accessibility/braille/braille_console.c b/drivers/accessibility/braille/braille_console.c new file mode 100644 index 00000000000..0a5f6b2114c --- /dev/null +++ b/drivers/accessibility/braille/braille_console.c @@ -0,0 +1,397 @@ +/* + * Minimalistic braille device kernel support. + * + * By default, shows console messages on the braille device. + * Pressing Insert switches to VC browsing. + * + * Copyright (C) Samuel Thibault + * + * This program is free software ; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation ; either version 2 of the License, or + * (at your option) any later version. + * + * 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 the program ; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include +#include +#include + +MODULE_AUTHOR("samuel.thibault@ens-lyon.org"); +MODULE_DESCRIPTION("braille device"); +MODULE_LICENSE("GPL"); + +/* + * Braille device support part. + */ + +/* Emit various sounds */ +static int sound; +module_param(sound, bool, 0); +MODULE_PARM_DESC(sound, "emit sounds"); + +static void beep(unsigned int freq) +{ + if (sound) + kd_mksound(freq, HZ/10); +} + +/* mini console */ +#define WIDTH 40 +#define BRAILLE_KEY KEY_INSERT +static u16 console_buf[WIDTH]; +static int console_cursor; + +/* mini view of VC */ +static int vc_x, vc_y, lastvc_x, lastvc_y; + +/* show console ? (or show VC) */ +static int console_show = 1; +/* pending newline ? */ +static int console_newline = 1; +static int lastVC = -1; + +static struct console *braille_co; + +/* Very VisioBraille-specific */ +static void braille_write(u16 *buf) +{ + static u16 lastwrite[WIDTH]; + unsigned char data[1 + 1 + 2*WIDTH + 2 + 1], csum = 0, *c; + u16 out; + int i; + + if (!braille_co) + return; + + if (!memcmp(lastwrite, buf, WIDTH * sizeof(*buf))) + return; + memcpy(lastwrite, buf, WIDTH * sizeof(*buf)); + +#define SOH 1 +#define STX 2 +#define ETX 2 +#define EOT 4 +#define ENQ 5 + data[0] = STX; + data[1] = '>'; + csum ^= '>'; + c = &data[2]; + for (i = 0; i < WIDTH; i++) { + out = buf[i]; + if (out >= 0x100) + out = '?'; + else if (out == 0x00) + out = ' '; + csum ^= out; + if (out <= 0x05) { + *c++ = SOH; + out |= 0x40; + } + *c++ = out; + } + + if (csum <= 0x05) { + *c++ = SOH; + csum |= 0x40; + } + *c++ = csum; + *c++ = ETX; + + braille_co->write(braille_co, data, c - data); +} + +/* Follow the VC cursor*/ +static void vc_follow_cursor(struct vc_data *vc) +{ + vc_x = vc->vc_x - (vc->vc_x % WIDTH); + vc_y = vc->vc_y; + lastvc_x = vc->vc_x; + lastvc_y = vc->vc_y; +} + +/* Maybe the VC cursor moved, if so follow it */ +static void vc_maybe_cursor_moved(struct vc_data *vc) +{ + if (vc->vc_x != lastvc_x || vc->vc_y != lastvc_y) + vc_follow_cursor(vc); +} + +/* Show portion of VC at vc_x, vc_y */ +static void vc_refresh(struct vc_data *vc) +{ + u16 buf[WIDTH]; + int i; + + for (i = 0; i < WIDTH; i++) { + u16 glyph = screen_glyph(vc, + 2 * (vc_x + i) + vc_y * vc->vc_size_row); + buf[i] = inverse_translate(vc, glyph, 1); + } + braille_write(buf); +} + +/* + * Link to keyboard + */ + +static int keyboard_notifier_call(struct notifier_block *blk, + unsigned long code, void *_param) +{ + struct keyboard_notifier_param *param = _param; + struct vc_data *vc = param->vc; + int ret = NOTIFY_OK; + + if (!param->down) + return ret; + + switch (code) { + case KBD_KEYCODE: + if (console_show) { + if (param->value == BRAILLE_KEY) { + console_show = 0; + beep(880); + vc_maybe_cursor_moved(vc); + vc_refresh(vc); + ret = NOTIFY_STOP; + } + } else { + ret = NOTIFY_STOP; + switch (param->value) { + case KEY_INSERT: + beep(440); + console_show = 1; + lastVC = -1; + braille_write(console_buf); + break; + case KEY_LEFT: + if (vc_x > 0) { + vc_x -= WIDTH; + if (vc_x < 0) + vc_x = 0; + } else if (vc_y >= 1) { + beep(880); + vc_y--; + vc_x = vc->vc_cols-WIDTH; + } else + beep(220); + break; + case KEY_RIGHT: + if (vc_x + WIDTH < vc->vc_cols) { + vc_x += WIDTH; + } else if (vc_y + 1 < vc->vc_rows) { + beep(880); + vc_y++; + vc_x = 0; + } else + beep(220); + break; + case KEY_DOWN: + if (vc_y + 1 < vc->vc_rows) + vc_y++; + else + beep(220); + break; + case KEY_UP: + if (vc_y >= 1) + vc_y--; + else + beep(220); + break; + case KEY_HOME: + vc_follow_cursor(vc); + break; + case KEY_PAGEUP: + vc_x = 0; + vc_y = 0; + break; + case KEY_PAGEDOWN: + vc_x = 0; + vc_y = vc->vc_rows-1; + break; + default: + ret = NOTIFY_OK; + break; + } + if (ret == NOTIFY_STOP) + vc_refresh(vc); + } + break; + case KBD_POST_KEYSYM: + { + unsigned char type = KTYP(param->value) - 0xf0; + if (type == KT_SPEC) { + unsigned char val = KVAL(param->value); + int on_off = -1; + + switch (val) { + case KVAL(K_CAPS): + on_off = vc_kbd_led(kbd_table + fg_console, + VC_CAPSLOCK); + break; + case KVAL(K_NUM): + on_off = vc_kbd_led(kbd_table + fg_console, + VC_NUMLOCK); + break; + case KVAL(K_HOLD): + on_off = vc_kbd_led(kbd_table + fg_console, + VC_SCROLLOCK); + break; + } + if (on_off == 1) + beep(880); + else if (on_off == 0) + beep(440); + } + } + case KBD_UNBOUND_KEYCODE: + case KBD_UNICODE: + case KBD_KEYSYM: + /* Unused */ + break; + } + return ret; +} + +static struct notifier_block keyboard_notifier_block = { + .notifier_call = keyboard_notifier_call, +}; + +static int vt_notifier_call(struct notifier_block *blk, + unsigned long code, void *_param) +{ + struct vt_notifier_param *param = _param; + struct vc_data *vc = param->vc; + switch (code) { + case VT_ALLOCATE: + break; + case VT_DEALLOCATE: + break; + case VT_WRITE: + { + unsigned char c = param->c; + if (vc->vc_num != fg_console) + break; + switch (c) { + case '\b': + case 127: + if (console_cursor > 0) { + console_cursor--; + console_buf[console_cursor] = ' '; + } + break; + case '\n': + case '\v': + case '\f': + case '\r': + console_newline = 1; + break; + case '\t': + c = ' '; + /* Fallthrough */ + default: + if (c < 32) + /* Ignore other control sequences */ + break; + if (console_newline) { + memset(console_buf, 0, sizeof(console_buf)); + console_cursor = 0; + console_newline = 0; + } + if (console_cursor == WIDTH) + memmove(console_buf, &console_buf[1], + (WIDTH-1) * sizeof(*console_buf)); + else + console_cursor++; + console_buf[console_cursor-1] = c; + break; + } + if (console_show) + braille_write(console_buf); + else { + vc_maybe_cursor_moved(vc); + vc_refresh(vc); + } + break; + } + case VT_UPDATE: + /* Maybe a VT switch, flush */ + if (console_show) { + if (vc->vc_num != lastVC) { + lastVC = vc->vc_num; + memset(console_buf, 0, sizeof(console_buf)); + console_cursor = 0; + braille_write(console_buf); + } + } else { + vc_maybe_cursor_moved(vc); + vc_refresh(vc); + } + break; + } + return NOTIFY_OK; +} + +static struct notifier_block vt_notifier_block = { + .notifier_call = vt_notifier_call, +}; + +/* + * Called from printk.c when console=brl is given + */ + +int braille_register_console(struct console *console, int index, + char *console_options, char *braille_options) +{ + int ret; + if (!console_options) + /* Only support VisioBraille for now */ + console_options = "57600o8"; + if (braille_co) + return -ENODEV; + if (console->setup) { + ret = console->setup(console, console_options); + if (ret != 0) + return ret; + } + console->flags |= CON_ENABLED; + console->index = index; + braille_co = console; + return 0; +} + +int braille_unregister_console(struct console *console) +{ + if (braille_co != console) + return -EINVAL; + braille_co = NULL; + return 0; +} + +static int __init braille_init(void) +{ + register_keyboard_notifier(&keyboard_notifier_block); + register_vt_notifier(&vt_notifier_block); + return 0; +} + +console_initcall(braille_init); 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