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path: root/drivers/video/fbdev/cobalt_lcdfb.c
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Diffstat (limited to 'drivers/video/fbdev/cobalt_lcdfb.c')
-rw-r--r--drivers/video/fbdev/cobalt_lcdfb.c351
1 files changed, 351 insertions, 0 deletions
diff --git a/drivers/video/fbdev/cobalt_lcdfb.c b/drivers/video/fbdev/cobalt_lcdfb.c
new file mode 100644
index 000000000..5f8b6324d
--- /dev/null
+++ b/drivers/video/fbdev/cobalt_lcdfb.c
@@ -0,0 +1,351 @@
+// 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;
+
+ 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 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;
+ info->flags = FBINFO_DEFAULT;
+
+ 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 int cobalt_lcdfb_remove(struct platform_device *dev)
+{
+ struct fb_info *info;
+
+ info = platform_get_drvdata(dev);
+ if (info) {
+ unregister_framebuffer(info);
+ framebuffer_release(info);
+ }
+
+ return 0;
+}
+
+static struct platform_driver cobalt_lcdfb_driver = {
+ .probe = cobalt_lcdfb_probe,
+ .remove = 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");