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
30enum {
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
45struct 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
56static 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
72static 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
79static int
80goldfish_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
96static 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
124static 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
136static 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
155static 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
169static 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
182static 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
276err_register_framebuffer_failed:
277	free_irq(fb->irq, fb);
278err_request_irq_failed:
279err_fb_set_var_failed:
280	dma_free_coherent(&pdev->dev, framesize,
281				(void *)fb->fb.screen_base,
282				fb->fb.fix.smem_start);
283err_alloc_screen_base_failed:
284err_no_irq:
285	iounmap(fb->reg_base);
286err_no_io_base:
287	kfree(fb);
288err_fb_alloc_failed:
289	return ret;
290}
291
292static 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
308static struct platform_driver goldfish_fb_driver = {
309	.probe		= goldfish_fb_probe,
310	.remove		= goldfish_fb_remove,
311	.driver = {
312		.name = "goldfish_fb"
313	}
314};
315
316module_platform_driver(goldfish_fb_driver);
317
318MODULE_LICENSE("GPL v2");
319