/* * Cobalt server LCD frame buffer driver. * * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org> * * 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 this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <linux/delay.h> #include <linux/fb.h> #include <linux/init.h> #include <linux/io.h> #include <linux/ioport.h> #include <linux/uaccess.h> #include <linux/platform_device.h> /* * Cursor position address * \X 0 1 2 ... 14 15 * Y+----+----+----+---+----+----+ * 0|0x00|0x01|0x02|...|0x0e|0x0f| * +----+----+----+---+----+----+ * 1|0x40|0x41|0x42|...|0x4e|0x4f| * +----+----+----+---+----+----+ */ #define LCD_DATA_REG_OFFSET 0x10 #define LCD_XRES_MAX 16 #define LCD_YRES_MAX 2 #define LCD_CHARS_MAX 32 #define LCD_CLEAR 0x01 #define LCD_CURSOR_MOVE_HOME 0x02 #define LCD_RESET 0x06 #define LCD_OFF 0x08 #define LCD_CURSOR_OFF 0x0c #define LCD_CURSOR_BLINK_OFF 0x0e #define LCD_CURSOR_ON 0x0f #define LCD_ON LCD_CURSOR_ON #define LCD_CURSOR_MOVE_LEFT 0x10 #define LCD_CURSOR_MOVE_RIGHT 0x14 #define LCD_DISPLAY_LEFT 0x18 #define LCD_DISPLAY_RIGHT 0x1c #define LCD_PRERESET 0x3f /* execute 4 times continuously */ #define LCD_BUSY 0x80 #define LCD_GRAPHIC_MODE 0x40 #define LCD_TEXT_MODE 0x80 #define LCD_CUR_POS_MASK 0x7f #define LCD_CUR_POS(x) ((x) & LCD_CUR_POS_MASK) #define LCD_TEXT_POS(x) ((x) | LCD_TEXT_MODE) static inline void lcd_write_control(struct fb_info *info, u8 control) { writel((u32)control << 24, info->screen_base); } static inline u8 lcd_read_control(struct fb_info *info) { return readl(info->screen_base) >> 24; } static inline void lcd_write_data(struct fb_info *info, u8 data) { writel((u32)data << 24, info->screen_base + LCD_DATA_REG_OFFSET); } static inline u8 lcd_read_data(struct fb_info *info) { return readl(info->screen_base + LCD_DATA_REG_OFFSET) >> 24; } static int lcd_busy_wait(struct fb_info *info) { u8 val = 0; int timeout = 10, retval = 0; do { val = lcd_read_control(info); val &= LCD_BUSY; if (val != LCD_BUSY) break; if (msleep_interruptible(1)) return -EINTR; timeout--; } while (timeout); if (val == LCD_BUSY) retval = -EBUSY; return retval; } static void lcd_clear(struct fb_info *info) { int i; for (i = 0; i < 4; i++) { udelay(150); lcd_write_control(info, LCD_PRERESET); } udelay(150); lcd_write_control(info, LCD_CLEAR); udelay(150); lcd_write_control(info, LCD_RESET); } static struct fb_fix_screeninfo cobalt_lcdfb_fix __initdata = { .id = "cobalt-lcd", .type = FB_TYPE_TEXT, .type_aux = FB_AUX_TEXT_MDA, .visual = FB_VISUAL_MONO01, .line_length = LCD_XRES_MAX, .accel = FB_ACCEL_NONE, }; static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf, size_t count, loff_t *ppos) { char src[LCD_CHARS_MAX]; unsigned long pos; int len, retval = 0; pos = *ppos; if (pos >= LCD_CHARS_MAX || count == 0) return 0; if (count > LCD_CHARS_MAX) count = LCD_CHARS_MAX; if (pos + count > LCD_CHARS_MAX) count = LCD_CHARS_MAX - pos; for (len = 0; len < count; len++) { retval = lcd_busy_wait(info); if (retval < 0) break; lcd_write_control(info, LCD_TEXT_POS(pos)); retval = lcd_busy_wait(info); if (retval < 0) break; src[len] = lcd_read_data(info); if (pos == 0x0f) pos = 0x40; else pos++; } if (retval < 0 && signal_pending(current)) return -ERESTARTSYS; if (copy_to_user(buf, src, len)) return -EFAULT; *ppos += len; return len; } static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf, size_t count, loff_t *ppos) { char dst[LCD_CHARS_MAX]; unsigned long pos; int len, retval = 0; pos = *ppos; if (pos >= LCD_CHARS_MAX || count == 0) return 0; if (count > LCD_CHARS_MAX) count = LCD_CHARS_MAX; if (pos + count > LCD_CHARS_MAX) count = LCD_CHARS_MAX - pos; if (copy_from_user(dst, buf, count)) return -EFAULT; for (len = 0; len < count; len++) { retval = lcd_busy_wait(info); if (retval < 0) break; lcd_write_control(info, LCD_TEXT_POS(pos)); retval = lcd_busy_wait(info); if (retval < 0) break; lcd_write_data(info, dst[len]); if (pos == 0x0f) pos = 0x40; else pos++; } if (retval < 0 && signal_pending(current)) return -ERESTARTSYS; *ppos += len; return len; } static int cobalt_lcdfb_blank(int blank_mode, struct fb_info *info) { int retval; retval = lcd_busy_wait(info); if (retval < 0) return retval; switch (blank_mode) { case FB_BLANK_UNBLANK: lcd_write_control(info, LCD_ON); break; default: lcd_write_control(info, LCD_OFF); break; } return 0; } static int cobalt_lcdfb_cursor(struct fb_info *info, struct fb_cursor *cursor) { u32 x, y; int retval; switch (cursor->set) { case FB_CUR_SETPOS: x = cursor->image.dx; y = cursor->image.dy; if (x >= LCD_XRES_MAX || y >= LCD_YRES_MAX) return -EINVAL; retval = lcd_busy_wait(info); if (retval < 0) return retval; lcd_write_control(info, LCD_TEXT_POS(info->fix.line_length * y + x)); break; default: return -EINVAL; } retval = lcd_busy_wait(info); if (retval < 0) return retval; if (cursor->enable) lcd_write_control(info, LCD_CURSOR_ON); else lcd_write_control(info, LCD_CURSOR_OFF); return 0; } static struct fb_ops cobalt_lcd_fbops = { .owner = THIS_MODULE, .fb_read = cobalt_lcdfb_read, .fb_write = cobalt_lcdfb_write, .fb_blank = cobalt_lcdfb_blank, .fb_cursor = cobalt_lcdfb_cursor, }; static int __init cobalt_lcdfb_probe(struct platform_device *dev) { struct fb_info *info; struct resource *res; int retval; info = framebuffer_alloc(0, &dev->dev); if (!info) return -ENOMEM; res = platform_get_resource(dev, IORESOURCE_MEM, 0); if (!res) { framebuffer_release(info); return -EBUSY; } info->screen_size = res->end - res->start + 1; info->screen_base = ioremap(res->start, info->screen_size); info->fbops = &cobalt_lcd_fbops; info->fix = cobalt_lcdfb_fix; info->fix.smem_start = res->start; info->fix.smem_len = info->screen_size; info->pseudo_palette = NULL; info->par = NULL; info->flags = FBINFO_DEFAULT; retval = register_framebuffer(info); if (retval < 0) { iounmap(info->screen_base); framebuffer_release(info); return retval; } platform_set_drvdata(dev, info); lcd_clear(info); printk(KERN_INFO "fb%d: Cobalt server LCD frame buffer device\n", info->node); return 0; } static int __devexit cobalt_lcdfb_remove(struct platform_device *dev) { struct fb_info *info; info = platform_get_drvdata(dev); if (info) { iounmap(info->screen_base); unregister_framebuffer(info); framebuffer_release(info); } return 0; } static struct platform_driver cobalt_lcdfb_driver = { .probe = cobalt_lcdfb_probe, .remove = __devexit_p(cobalt_lcdfb_remove), .driver = { .name = "cobalt-lcd", .owner = THIS_MODULE, }, }; static int __init cobalt_lcdfb_init(void) { return platform_driver_register(&cobalt_lcdfb_driver); } static void __exit cobalt_lcdfb_exit(void) { platform_driver_unregister(&cobalt_lcdfb_driver); } module_init(cobalt_lcdfb_init); module_exit(cobalt_lcdfb_exit); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Yoichi Yuasa"); MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver");