4 * Xilinx TFT LCD frame buffer driver
6 * Author: MontaVista Software, Inc.
9 * 2002-2007 (c) MontaVista Software, Inc. This file is licensed under the
10 * terms of the GNU General Public License version 2. This program is licensed
11 * "as is" without any warranty of any kind, whether express or implied.
15 * This driver was based on au1100fb.c by MontaVista rewritten for 2.6
16 * by Embedded Alley Solutions <source@embeddedalley.com>, which in turn
17 * was based on skeletonfb.c, Skeleton for a frame buffer device by
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/version.h>
24 #include <linux/errno.h>
25 #include <linux/string.h>
28 #include <linux/init.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/platform_device.h>
33 #include <syslib/virtex_devices.h>
35 #define DRIVER_NAME "xilinxfb"
36 #define DRIVER_DESCRIPTION "Xilinx TFT LCD frame buffer driver"
39 * Xilinx calls it "PLB TFT LCD Controller" though it can also be used for
40 * the VGA port on the Xilinx ML40x board. This is a hardware display controller
41 * for a 640x480 resolution TFT or VGA screen.
43 * The interface to the framebuffer is nice and simple. There are two
44 * control registers. The first tells the LCD interface where in memory
45 * the frame buffer is (only the 11 most significant bits are used, so
46 * don't start thinking about scrolling). The second allows the LCD to
47 * be turned on or off as well as rotated 180 degrees.
52 #define REG_CTRL_ENABLE 0x0001
53 #define REG_CTRL_ROTATE 0x0002
56 * The hardware only handles a single mode: 640x480 24 bit true
57 * color. Each pixel gets a word (32 bits) of memory. Within each word,
58 * the 8 most significant bits are ignored, the next 8 bits are the red
59 * level, the next 8 bits are the green level and the 8 least
60 * significant bits are the blue level. Each row of the LCD uses 1024
61 * words, but only the first 640 pixels are displayed with the other 384
62 * words being ignored. There are 480 rows.
64 #define BYTES_PER_PIXEL 4
65 #define BITS_PER_PIXEL (BYTES_PER_PIXEL * 8)
68 #define XRES_VIRTUAL 1024
69 #define YRES_VIRTUAL YRES
70 #define LINE_LENGTH (XRES_VIRTUAL * BYTES_PER_PIXEL)
71 #define FB_SIZE (YRES_VIRTUAL * LINE_LENGTH)
77 #define PALETTE_ENTRIES_NO 16 /* passed to fb_alloc_cmap() */
80 * Here are the default fb_fix_screeninfo and fb_var_screeninfo structures
82 static struct fb_fix_screeninfo xilinx_fb_fix __initdata = {
84 .type = FB_TYPE_PACKED_PIXELS,
85 .visual = FB_VISUAL_TRUECOLOR,
87 .line_length = LINE_LENGTH,
88 .accel = FB_ACCEL_NONE
91 static struct fb_var_screeninfo xilinx_fb_var __initdata = {
94 .xres_virtual = XRES_VIRTUAL,
95 .yres_virtual = YRES_VIRTUAL,
97 .bits_per_pixel = BITS_PER_PIXEL,
99 .red = { RED_SHIFT, 8, 0 },
100 .green = { GREEN_SHIFT, 8, 0 },
101 .blue = { BLUE_SHIFT, 8, 0 },
102 .transp = { 0, 0, 0 },
104 .activate = FB_ACTIVATE_NOW
107 struct xilinxfb_drvdata {
109 struct fb_info info; /* FB driver info record */
111 u32 regs_phys; /* phys. address of the control registers */
112 u32 __iomem *regs; /* virt. address of the control registers */
114 unsigned char __iomem *fb_virt; /* virt. address of the frame buffer */
115 dma_addr_t fb_phys; /* phys. address of the frame buffer */
117 u32 reg_ctrl_default;
119 u32 pseudo_palette[PALETTE_ENTRIES_NO];
120 /* Fake palette of 16 colors */
123 #define to_xilinxfb_drvdata(_info) \
124 container_of(_info, struct xilinxfb_drvdata, info)
127 * The LCD controller has DCR interface to its registers, but all
128 * the boards and configurations the driver has been tested with
129 * use opb2dcr bridge. So the registers are seen as memory mapped.
130 * This macro is to make it simple to add the direct DCR access
133 #define xilinx_fb_out_be32(driverdata, offset, val) \
134 out_be32(driverdata->regs + offset, val)
137 xilinx_fb_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue,
138 unsigned transp, struct fb_info *fbi)
140 u32 *palette = fbi->pseudo_palette;
142 if (regno >= PALETTE_ENTRIES_NO)
145 if (fbi->var.grayscale) {
146 /* Convert color to grayscale.
147 * grayscale = 0.30*R + 0.59*G + 0.11*B */
149 (red * 77 + green * 151 + blue * 28 + 127) >> 8;
152 /* fbi->fix.visual is always FB_VISUAL_TRUECOLOR */
154 /* We only handle 8 bits of each color. */
158 palette[regno] = (red << RED_SHIFT) | (green << GREEN_SHIFT) |
159 (blue << BLUE_SHIFT);
165 xilinx_fb_blank(int blank_mode, struct fb_info *fbi)
167 struct xilinxfb_drvdata *drvdata = to_xilinxfb_drvdata(fbi);
169 switch (blank_mode) {
170 case FB_BLANK_UNBLANK:
172 xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);
175 case FB_BLANK_NORMAL:
176 case FB_BLANK_VSYNC_SUSPEND:
177 case FB_BLANK_HSYNC_SUSPEND:
178 case FB_BLANK_POWERDOWN:
180 xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
185 return 0; /* success */
188 static struct fb_ops xilinxfb_ops =
190 .owner = THIS_MODULE,
191 .fb_setcolreg = xilinx_fb_setcolreg,
192 .fb_blank = xilinx_fb_blank,
193 .fb_fillrect = cfb_fillrect,
194 .fb_copyarea = cfb_copyarea,
195 .fb_imageblit = cfb_imageblit,
198 /* === The device driver === */
201 xilinxfb_drv_probe(struct device *dev)
203 struct platform_device *pdev;
204 struct xilinxfb_platform_data *pdata;
205 struct xilinxfb_drvdata *drvdata;
206 struct resource *regs_res;
212 pdev = to_platform_device(dev);
213 pdata = pdev->dev.platform_data;
216 printk(KERN_ERR "Couldn't find platform data.\n");
220 drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
222 printk(KERN_ERR "Couldn't allocate device private record\n");
225 dev_set_drvdata(dev, drvdata);
227 /* Map the control registers in */
228 regs_res = platform_get_resource(pdev, IORESOURCE_IO, 0);
229 if (!regs_res || (regs_res->end - regs_res->start + 1 < 8)) {
230 printk(KERN_ERR "Couldn't get registers resource\n");
235 if (!request_mem_region(regs_res->start, 8, DRIVER_NAME)) {
237 "Couldn't lock memory region at 0x%08X\n",
242 drvdata->regs = (u32 __iomem*) ioremap(regs_res->start, 8);
243 drvdata->regs_phys = regs_res->start;
245 /* Allocate the framebuffer memory */
246 drvdata->fb_virt = dma_alloc_coherent(dev, PAGE_ALIGN(FB_SIZE),
247 &drvdata->fb_phys, GFP_KERNEL);
248 if (!drvdata->fb_virt) {
249 printk(KERN_ERR "Could not allocate frame buffer memory\n");
254 /* Clear (turn to black) the framebuffer */
255 memset_io((void *) drvdata->fb_virt, 0, FB_SIZE);
257 /* Tell the hardware where the frame buffer is */
258 xilinx_fb_out_be32(drvdata, REG_FB_ADDR, drvdata->fb_phys);
260 /* Turn on the display */
261 if (pdata->rotate_screen) {
262 drvdata->reg_ctrl_default = REG_CTRL_ENABLE | REG_CTRL_ROTATE;
264 drvdata->reg_ctrl_default = REG_CTRL_ENABLE;
266 xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);
268 /* Fill struct fb_info */
269 drvdata->info.device = dev;
270 drvdata->info.screen_base = drvdata->fb_virt;
271 drvdata->info.fbops = &xilinxfb_ops;
272 drvdata->info.fix = xilinx_fb_fix;
273 drvdata->info.fix.smem_start = drvdata->fb_phys;
274 drvdata->info.pseudo_palette = drvdata->pseudo_palette;
276 if (fb_alloc_cmap(&drvdata->info.cmap, PALETTE_ENTRIES_NO, 0) < 0) {
277 printk(KERN_ERR "Fail to allocate colormap (%d entries)\n",
283 drvdata->info.flags = FBINFO_DEFAULT;
284 xilinx_fb_var.height = pdata->screen_height_mm;
285 xilinx_fb_var.width = pdata->screen_width_mm;
286 drvdata->info.var = xilinx_fb_var;
288 /* Register new frame buffer */
289 if (register_framebuffer(&drvdata->info) < 0) {
290 printk(KERN_ERR "Could not register frame buffer\n");
295 return 0; /* success */
298 fb_dealloc_cmap(&drvdata->info.cmap);
301 dma_free_coherent(dev, PAGE_ALIGN(FB_SIZE), drvdata->fb_virt,
304 /* Turn off the display */
305 xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
306 iounmap(drvdata->regs);
309 release_mem_region(regs_res->start, 8);
313 dev_set_drvdata(dev, NULL);
319 xilinxfb_drv_remove(struct device *dev)
321 struct xilinxfb_drvdata *drvdata;
326 drvdata = (struct xilinxfb_drvdata *) dev_get_drvdata(dev);
328 #if !defined(CONFIG_FRAMEBUFFER_CONSOLE) && defined(CONFIG_LOGO)
329 xilinx_fb_blank(VESA_POWERDOWN, &drvdata->info);
332 unregister_framebuffer(&drvdata->info);
334 fb_dealloc_cmap(&drvdata->info.cmap);
336 dma_free_coherent(dev, PAGE_ALIGN(FB_SIZE), drvdata->fb_virt,
339 /* Turn off the display */
340 xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
341 iounmap(drvdata->regs);
343 release_mem_region(drvdata->regs_phys, 8);
346 dev_set_drvdata(dev, NULL);
352 static struct device_driver xilinxfb_driver = {
354 .bus = &platform_bus_type,
356 .probe = xilinxfb_drv_probe,
357 .remove = xilinxfb_drv_remove
364 * No kernel boot options used,
365 * so we just need to register the driver
367 return driver_register(&xilinxfb_driver);
371 xilinxfb_cleanup(void)
373 driver_unregister(&xilinxfb_driver);
376 module_init(xilinxfb_init);
377 module_exit(xilinxfb_cleanup);
379 MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
380 MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
381 MODULE_LICENSE("GPL");