xref: /openbmc/linux/drivers/video/fbdev/goldfishfb.c (revision 31ff6b2a)
1 /*
2  * Copyright (C) 2007 Google, Inc.
3  * Copyright (C) 2012 Intel, Inc.
4  *
5  * This software is licensed under the terms of the GNU General Public
6  * License version 2, as published by the Free Software Foundation, and
7  * may be copied, distributed, and modified under those terms.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  */
15 
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/errno.h>
20 #include <linux/string.h>
21 #include <linux/slab.h>
22 #include <linux/delay.h>
23 #include <linux/mm.h>
24 #include <linux/fb.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/ioport.h>
28 #include <linux/platform_device.h>
29 
30 enum {
31 	FB_GET_WIDTH        = 0x00,
32 	FB_GET_HEIGHT       = 0x04,
33 	FB_INT_STATUS       = 0x08,
34 	FB_INT_ENABLE       = 0x0c,
35 	FB_SET_BASE         = 0x10,
36 	FB_SET_ROTATION     = 0x14,
37 	FB_SET_BLANK        = 0x18,
38 	FB_GET_PHYS_WIDTH   = 0x1c,
39 	FB_GET_PHYS_HEIGHT  = 0x20,
40 
41 	FB_INT_VSYNC             = 1U << 0,
42 	FB_INT_BASE_UPDATE_DONE  = 1U << 1
43 };
44 
45 struct goldfish_fb {
46 	void __iomem *reg_base;
47 	int irq;
48 	spinlock_t lock;
49 	wait_queue_head_t wait;
50 	int base_update_count;
51 	int rotation;
52 	struct fb_info fb;
53 	u32 cmap[16];
54 };
55 
56 static irqreturn_t goldfish_fb_interrupt(int irq, void *dev_id)
57 {
58 	unsigned long irq_flags;
59 	struct goldfish_fb *fb = dev_id;
60 	u32 status;
61 
62 	spin_lock_irqsave(&fb->lock, irq_flags);
63 	status = readl(fb->reg_base + FB_INT_STATUS);
64 	if (status & FB_INT_BASE_UPDATE_DONE) {
65 		fb->base_update_count++;
66 		wake_up(&fb->wait);
67 	}
68 	spin_unlock_irqrestore(&fb->lock, irq_flags);
69 	return status ? IRQ_HANDLED : IRQ_NONE;
70 }
71 
72 static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
73 {
74 	unsigned int mask = (1 << bf->length) - 1;
75 
76 	return (val >> (16 - bf->length) & mask) << bf->offset;
77 }
78 
79 static int
80 goldfish_fb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
81 		 unsigned int blue, unsigned int transp, struct fb_info *info)
82 {
83 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
84 
85 	if (regno < 16) {
86 		fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) |
87 				  convert_bitfield(blue, &fb->fb.var.blue) |
88 				  convert_bitfield(green, &fb->fb.var.green) |
89 				  convert_bitfield(red, &fb->fb.var.red);
90 		return 0;
91 	} else {
92 		return 1;
93 	}
94 }
95 
96 static int goldfish_fb_check_var(struct fb_var_screeninfo *var,
97 							struct fb_info *info)
98 {
99 	if ((var->rotate & 1) != (info->var.rotate & 1)) {
100 		if ((var->xres != info->var.yres) ||
101 				(var->yres != info->var.xres) ||
102 				(var->xres_virtual != info->var.yres) ||
103 				(var->yres_virtual > info->var.xres * 2) ||
104 				(var->yres_virtual < info->var.xres)) {
105 			return -EINVAL;
106 		}
107 	} else {
108 		if ((var->xres != info->var.xres) ||
109 		   (var->yres != info->var.yres) ||
110 		   (var->xres_virtual != info->var.xres) ||
111 		   (var->yres_virtual > info->var.yres * 2) ||
112 		   (var->yres_virtual < info->var.yres)) {
113 			return -EINVAL;
114 		}
115 	}
116 	if ((var->xoffset != info->var.xoffset) ||
117 			(var->bits_per_pixel != info->var.bits_per_pixel) ||
118 			(var->grayscale != info->var.grayscale)) {
119 		return -EINVAL;
120 	}
121 	return 0;
122 }
123 
124 static int goldfish_fb_set_par(struct fb_info *info)
125 {
126 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
127 	if (fb->rotation != fb->fb.var.rotate) {
128 		info->fix.line_length = info->var.xres * 2;
129 		fb->rotation = fb->fb.var.rotate;
130 		writel(fb->rotation, fb->reg_base + FB_SET_ROTATION);
131 	}
132 	return 0;
133 }
134 
135 
136 static int goldfish_fb_pan_display(struct fb_var_screeninfo *var,
137 							struct fb_info *info)
138 {
139 	unsigned long irq_flags;
140 	int base_update_count;
141 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
142 
143 	spin_lock_irqsave(&fb->lock, irq_flags);
144 	base_update_count = fb->base_update_count;
145 	writel(fb->fb.fix.smem_start + fb->fb.var.xres * 2 * var->yoffset,
146 						fb->reg_base + FB_SET_BASE);
147 	spin_unlock_irqrestore(&fb->lock, irq_flags);
148 	wait_event_timeout(fb->wait,
149 			fb->base_update_count != base_update_count, HZ / 15);
150 	if (fb->base_update_count == base_update_count)
151 		pr_err("goldfish_fb_pan_display: timeout waiting for base update\n");
152 	return 0;
153 }
154 
155 static int goldfish_fb_blank(int blank, struct fb_info *info)
156 {
157 	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
158 	switch (blank) {
159 	case FB_BLANK_NORMAL:
160 		writel(1, fb->reg_base + FB_SET_BLANK);
161 		break;
162 	case FB_BLANK_UNBLANK:
163 		writel(0, fb->reg_base + FB_SET_BLANK);
164 		break;
165 	}
166 	return 0;
167 }
168 
169 static struct fb_ops goldfish_fb_ops = {
170 	.owner          = THIS_MODULE,
171 	.fb_check_var   = goldfish_fb_check_var,
172 	.fb_set_par     = goldfish_fb_set_par,
173 	.fb_setcolreg   = goldfish_fb_setcolreg,
174 	.fb_pan_display = goldfish_fb_pan_display,
175 	.fb_blank	= goldfish_fb_blank,
176 	.fb_fillrect    = cfb_fillrect,
177 	.fb_copyarea    = cfb_copyarea,
178 	.fb_imageblit   = cfb_imageblit,
179 };
180 
181 
182 static int goldfish_fb_probe(struct platform_device *pdev)
183 {
184 	int ret;
185 	struct resource *r;
186 	struct goldfish_fb *fb;
187 	size_t framesize;
188 	u32 width, height;
189 	dma_addr_t fbpaddr;
190 
191 	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
192 	if (fb == NULL) {
193 		ret = -ENOMEM;
194 		goto err_fb_alloc_failed;
195 	}
196 	spin_lock_init(&fb->lock);
197 	init_waitqueue_head(&fb->wait);
198 	platform_set_drvdata(pdev, fb);
199 
200 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
201 	if (r == NULL) {
202 		ret = -ENODEV;
203 		goto err_no_io_base;
204 	}
205 	fb->reg_base = ioremap(r->start, PAGE_SIZE);
206 	if (fb->reg_base == NULL) {
207 		ret = -ENOMEM;
208 		goto err_no_io_base;
209 	}
210 
211 	fb->irq = platform_get_irq(pdev, 0);
212 	if (fb->irq <= 0) {
213 		ret = -ENODEV;
214 		goto err_no_irq;
215 	}
216 
217 	width = readl(fb->reg_base + FB_GET_WIDTH);
218 	height = readl(fb->reg_base + FB_GET_HEIGHT);
219 
220 	fb->fb.fbops		= &goldfish_fb_ops;
221 	fb->fb.flags		= FBINFO_FLAG_DEFAULT;
222 	fb->fb.pseudo_palette	= fb->cmap;
223 	fb->fb.fix.type		= FB_TYPE_PACKED_PIXELS;
224 	fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
225 	fb->fb.fix.line_length = width * 2;
226 	fb->fb.fix.accel	= FB_ACCEL_NONE;
227 	fb->fb.fix.ypanstep = 1;
228 
229 	fb->fb.var.xres		= width;
230 	fb->fb.var.yres		= height;
231 	fb->fb.var.xres_virtual	= width;
232 	fb->fb.var.yres_virtual	= height * 2;
233 	fb->fb.var.bits_per_pixel = 16;
234 	fb->fb.var.activate	= FB_ACTIVATE_NOW;
235 	fb->fb.var.height	= readl(fb->reg_base + FB_GET_PHYS_HEIGHT);
236 	fb->fb.var.width	= readl(fb->reg_base + FB_GET_PHYS_WIDTH);
237 	fb->fb.var.pixclock	= 10000;
238 
239 	fb->fb.var.red.offset = 11;
240 	fb->fb.var.red.length = 5;
241 	fb->fb.var.green.offset = 5;
242 	fb->fb.var.green.length = 6;
243 	fb->fb.var.blue.offset = 0;
244 	fb->fb.var.blue.length = 5;
245 
246 	framesize = width * height * 2 * 2;
247 	fb->fb.screen_base = (char __force __iomem *)dma_alloc_coherent(
248 						&pdev->dev, framesize,
249 						&fbpaddr, GFP_KERNEL);
250 	pr_debug("allocating frame buffer %d * %d, got %p\n",
251 					width, height, fb->fb.screen_base);
252 	if (fb->fb.screen_base == NULL) {
253 		ret = -ENOMEM;
254 		goto err_alloc_screen_base_failed;
255 	}
256 	fb->fb.fix.smem_start = fbpaddr;
257 	fb->fb.fix.smem_len = framesize;
258 
259 	ret = fb_set_var(&fb->fb, &fb->fb.var);
260 	if (ret)
261 		goto err_fb_set_var_failed;
262 
263 	ret = request_irq(fb->irq, goldfish_fb_interrupt, IRQF_SHARED,
264 							pdev->name, fb);
265 	if (ret)
266 		goto err_request_irq_failed;
267 
268 	writel(FB_INT_BASE_UPDATE_DONE, fb->reg_base + FB_INT_ENABLE);
269 	goldfish_fb_pan_display(&fb->fb.var, &fb->fb); /* updates base */
270 
271 	ret = register_framebuffer(&fb->fb);
272 	if (ret)
273 		goto err_register_framebuffer_failed;
274 	return 0;
275 
276 err_register_framebuffer_failed:
277 	free_irq(fb->irq, fb);
278 err_request_irq_failed:
279 err_fb_set_var_failed:
280 	dma_free_coherent(&pdev->dev, framesize,
281 				(void *)fb->fb.screen_base,
282 				fb->fb.fix.smem_start);
283 err_alloc_screen_base_failed:
284 err_no_irq:
285 	iounmap(fb->reg_base);
286 err_no_io_base:
287 	kfree(fb);
288 err_fb_alloc_failed:
289 	return ret;
290 }
291 
292 static int goldfish_fb_remove(struct platform_device *pdev)
293 {
294 	size_t framesize;
295 	struct goldfish_fb *fb = platform_get_drvdata(pdev);
296 
297 	framesize = fb->fb.var.xres_virtual * fb->fb.var.yres_virtual * 2;
298 	unregister_framebuffer(&fb->fb);
299 	free_irq(fb->irq, fb);
300 
301 	dma_free_coherent(&pdev->dev, framesize, (void *)fb->fb.screen_base,
302 						fb->fb.fix.smem_start);
303 	iounmap(fb->reg_base);
304 	return 0;
305 }
306 
307 static const struct of_device_id goldfish_fb_of_match[] = {
308 	{ .compatible = "google,goldfish-fb", },
309 	{},
310 };
311 MODULE_DEVICE_TABLE(of, goldfish_fb_of_match);
312 
313 static struct platform_driver goldfish_fb_driver = {
314 	.probe		= goldfish_fb_probe,
315 	.remove		= goldfish_fb_remove,
316 	.driver = {
317 		.name = "goldfish_fb",
318 		.of_match_table = goldfish_fb_of_match,
319 	}
320 };
321 
322 module_platform_driver(goldfish_fb_driver);
323 
324 MODULE_LICENSE("GPL v2");
325