diff options
Diffstat (limited to 'drivers/video/fbdev/cobalt_lcdfb.c')
| -rw-r--r-- | drivers/video/fbdev/cobalt_lcdfb.c | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/drivers/video/fbdev/cobalt_lcdfb.c b/drivers/video/fbdev/cobalt_lcdfb.c new file mode 100644 index 0000000000..b94e7c9726 --- /dev/null +++ b/drivers/video/fbdev/cobalt_lcdfb.c @@ -0,0 +1,354 @@ +// 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_cursor = cobalt_lcdfb_cursor, +}; + +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"); |