| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Cobalt/SEAD3 LCD frame buffer driver. |
| * |
| * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org> |
| * Copyright (C) 2012 MIPS Technologies, Inc. |
| */ |
| #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> |
| #include <linux/module.h> |
| #include <linux/sched/signal.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 const struct fb_fix_screeninfo cobalt_lcdfb_fix = { |
| .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; |
| |
| if (!info->screen_base) |
| return -ENODEV; |
| |
| 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; |
| |
| if (!info->screen_base) |
| return -ENODEV; |
| |
| 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 const 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_DEFAULT_IOMEM_OPS_DRAW, |
| .fb_cursor = cobalt_lcdfb_cursor, |
| __FB_DEFAULT_IOMEM_OPS_MMAP, |
| }; |
| |
| static int 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 = resource_size(res); |
| info->screen_base = devm_ioremap(&dev->dev, res->start, |
| info->screen_size); |
| if (!info->screen_base) { |
| framebuffer_release(info); |
| return -ENOMEM; |
| } |
| |
| 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; |
| |
| retval = register_framebuffer(info); |
| if (retval < 0) { |
| framebuffer_release(info); |
| return retval; |
| } |
| |
| platform_set_drvdata(dev, info); |
| |
| lcd_clear(info); |
| |
| fb_info(info, "Cobalt server LCD frame buffer device\n"); |
| |
| return 0; |
| } |
| |
| static void cobalt_lcdfb_remove(struct platform_device *dev) |
| { |
| struct fb_info *info; |
| |
| info = platform_get_drvdata(dev); |
| if (info) { |
| unregister_framebuffer(info); |
| framebuffer_release(info); |
| } |
| } |
| |
| static struct platform_driver cobalt_lcdfb_driver = { |
| .probe = cobalt_lcdfb_probe, |
| .remove_new = cobalt_lcdfb_remove, |
| .driver = { |
| .name = "cobalt-lcd", |
| }, |
| }; |
| module_platform_driver(cobalt_lcdfb_driver); |
| |
| MODULE_LICENSE("GPL v2"); |
| MODULE_AUTHOR("Yoichi Yuasa"); |
| MODULE_DESCRIPTION("Cobalt server LCD frame buffer driver"); |
