1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2007 Google, Inc.
4 * Copyright (C) 2012 Intel, Inc.
5 */
6
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/dma-mapping.h>
10#include <linux/errno.h>
11#include <linux/string.h>
12#include <linux/slab.h>
13#include <linux/delay.h>
14#include <linux/mm.h>
15#include <linux/fb.h>
16#include <linux/init.h>
17#include <linux/interrupt.h>
18#include <linux/ioport.h>
19#include <linux/platform_device.h>
20#include <linux/acpi.h>
21
22enum {
23	FB_GET_WIDTH        = 0x00,
24	FB_GET_HEIGHT       = 0x04,
25	FB_INT_STATUS       = 0x08,
26	FB_INT_ENABLE       = 0x0c,
27	FB_SET_BASE         = 0x10,
28	FB_SET_ROTATION     = 0x14,
29	FB_SET_BLANK        = 0x18,
30	FB_GET_PHYS_WIDTH   = 0x1c,
31	FB_GET_PHYS_HEIGHT  = 0x20,
32
33	FB_INT_VSYNC             = 1U << 0,
34	FB_INT_BASE_UPDATE_DONE  = 1U << 1
35};
36
37struct goldfish_fb {
38	void __iomem *reg_base;
39	int irq;
40	spinlock_t lock;
41	wait_queue_head_t wait;
42	int base_update_count;
43	int rotation;
44	struct fb_info fb;
45	u32 cmap[16];
46};
47
48static irqreturn_t goldfish_fb_interrupt(int irq, void *dev_id)
49{
50	unsigned long irq_flags;
51	struct goldfish_fb *fb = dev_id;
52	u32 status;
53
54	spin_lock_irqsave(&fb->lock, irq_flags);
55	status = readl(fb->reg_base + FB_INT_STATUS);
56	if (status & FB_INT_BASE_UPDATE_DONE) {
57		fb->base_update_count++;
58		wake_up(&fb->wait);
59	}
60	spin_unlock_irqrestore(&fb->lock, irq_flags);
61	return status ? IRQ_HANDLED : IRQ_NONE;
62}
63
64static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
65{
66	unsigned int mask = (1 << bf->length) - 1;
67
68	return (val >> (16 - bf->length) & mask) << bf->offset;
69}
70
71static int
72goldfish_fb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
73		 unsigned int blue, unsigned int transp, struct fb_info *info)
74{
75	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
76
77	if (regno < 16) {
78		fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) |
79				  convert_bitfield(blue, &fb->fb.var.blue) |
80				  convert_bitfield(green, &fb->fb.var.green) |
81				  convert_bitfield(red, &fb->fb.var.red);
82		return 0;
83	} else {
84		return 1;
85	}
86}
87
88static int goldfish_fb_check_var(struct fb_var_screeninfo *var,
89							struct fb_info *info)
90{
91	if ((var->rotate & 1) != (info->var.rotate & 1)) {
92		if ((var->xres != info->var.yres) ||
93				(var->yres != info->var.xres) ||
94				(var->xres_virtual != info->var.yres) ||
95				(var->yres_virtual > info->var.xres * 2) ||
96				(var->yres_virtual < info->var.xres)) {
97			return -EINVAL;
98		}
99	} else {
100		if ((var->xres != info->var.xres) ||
101		   (var->yres != info->var.yres) ||
102		   (var->xres_virtual != info->var.xres) ||
103		   (var->yres_virtual > info->var.yres * 2) ||
104		   (var->yres_virtual < info->var.yres)) {
105			return -EINVAL;
106		}
107	}
108	if ((var->xoffset != info->var.xoffset) ||
109			(var->bits_per_pixel != info->var.bits_per_pixel) ||
110			(var->grayscale != info->var.grayscale)) {
111		return -EINVAL;
112	}
113	return 0;
114}
115
116static int goldfish_fb_set_par(struct fb_info *info)
117{
118	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
119
120	if (fb->rotation != fb->fb.var.rotate) {
121		info->fix.line_length = info->var.xres * 2;
122		fb->rotation = fb->fb.var.rotate;
123		writel(fb->rotation, fb->reg_base + FB_SET_ROTATION);
124	}
125	return 0;
126}
127
128
129static int goldfish_fb_pan_display(struct fb_var_screeninfo *var,
130							struct fb_info *info)
131{
132	unsigned long irq_flags;
133	int base_update_count;
134	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
135
136	spin_lock_irqsave(&fb->lock, irq_flags);
137	base_update_count = fb->base_update_count;
138	writel(fb->fb.fix.smem_start + fb->fb.var.xres * 2 * var->yoffset,
139						fb->reg_base + FB_SET_BASE);
140	spin_unlock_irqrestore(&fb->lock, irq_flags);
141	wait_event_timeout(fb->wait,
142			fb->base_update_count != base_update_count, HZ / 15);
143	if (fb->base_update_count == base_update_count)
144		pr_err("%s: timeout waiting for base update\n", __func__);
145	return 0;
146}
147
148static int goldfish_fb_blank(int blank, struct fb_info *info)
149{
150	struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
151
152	switch (blank) {
153	case FB_BLANK_NORMAL:
154		writel(1, fb->reg_base + FB_SET_BLANK);
155		break;
156	case FB_BLANK_UNBLANK:
157		writel(0, fb->reg_base + FB_SET_BLANK);
158		break;
159	}
160	return 0;
161}
162
163static const struct fb_ops goldfish_fb_ops = {
164	.owner          = THIS_MODULE,
165	.fb_check_var   = goldfish_fb_check_var,
166	.fb_set_par     = goldfish_fb_set_par,
167	.fb_setcolreg   = goldfish_fb_setcolreg,
168	.fb_pan_display = goldfish_fb_pan_display,
169	.fb_blank	= goldfish_fb_blank,
170	.fb_fillrect    = cfb_fillrect,
171	.fb_copyarea    = cfb_copyarea,
172	.fb_imageblit   = cfb_imageblit,
173};
174
175
176static int goldfish_fb_probe(struct platform_device *pdev)
177{
178	int ret;
179	struct resource *r;
180	struct goldfish_fb *fb;
181	size_t framesize;
182	u32 width, height;
183	dma_addr_t fbpaddr;
184
185	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
186	if (fb == NULL) {
187		ret = -ENOMEM;
188		goto err_fb_alloc_failed;
189	}
190	spin_lock_init(&fb->lock);
191	init_waitqueue_head(&fb->wait);
192	platform_set_drvdata(pdev, fb);
193
194	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
195	if (r == NULL) {
196		ret = -ENODEV;
197		goto err_no_io_base;
198	}
199	fb->reg_base = ioremap(r->start, PAGE_SIZE);
200	if (fb->reg_base == NULL) {
201		ret = -ENOMEM;
202		goto err_no_io_base;
203	}
204
205	fb->irq = platform_get_irq(pdev, 0);
206	if (fb->irq <= 0) {
207		ret = -ENODEV;
208		goto err_no_irq;
209	}
210
211	width = readl(fb->reg_base + FB_GET_WIDTH);
212	height = readl(fb->reg_base + FB_GET_HEIGHT);
213
214	fb->fb.fbops		= &goldfish_fb_ops;
215	fb->fb.flags		= FBINFO_FLAG_DEFAULT;
216	fb->fb.pseudo_palette	= fb->cmap;
217	fb->fb.fix.type		= FB_TYPE_PACKED_PIXELS;
218	fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
219	fb->fb.fix.line_length = width * 2;
220	fb->fb.fix.accel	= FB_ACCEL_NONE;
221	fb->fb.fix.ypanstep = 1;
222
223	fb->fb.var.xres		= width;
224	fb->fb.var.yres		= height;
225	fb->fb.var.xres_virtual	= width;
226	fb->fb.var.yres_virtual	= height * 2;
227	fb->fb.var.bits_per_pixel = 16;
228	fb->fb.var.activate	= FB_ACTIVATE_NOW;
229	fb->fb.var.height	= readl(fb->reg_base + FB_GET_PHYS_HEIGHT);
230	fb->fb.var.width	= readl(fb->reg_base + FB_GET_PHYS_WIDTH);
231	fb->fb.var.pixclock	= 0;
232
233	fb->fb.var.red.offset = 11;
234	fb->fb.var.red.length = 5;
235	fb->fb.var.green.offset = 5;
236	fb->fb.var.green.length = 6;
237	fb->fb.var.blue.offset = 0;
238	fb->fb.var.blue.length = 5;
239
240	framesize = width * height * 2 * 2;
241	fb->fb.screen_base = (char __force __iomem *)dma_alloc_coherent(
242						&pdev->dev, framesize,
243						&fbpaddr, GFP_KERNEL);
244	pr_debug("allocating frame buffer %d * %d, got %p\n",
245					width, height, fb->fb.screen_base);
246	if (fb->fb.screen_base == NULL) {
247		ret = -ENOMEM;
248		goto err_alloc_screen_base_failed;
249	}
250	fb->fb.fix.smem_start = fbpaddr;
251	fb->fb.fix.smem_len = framesize;
252
253	ret = fb_set_var(&fb->fb, &fb->fb.var);
254	if (ret)
255		goto err_fb_set_var_failed;
256
257	ret = request_irq(fb->irq, goldfish_fb_interrupt, IRQF_SHARED,
258							pdev->name, fb);
259	if (ret)
260		goto err_request_irq_failed;
261
262	writel(FB_INT_BASE_UPDATE_DONE, fb->reg_base + FB_INT_ENABLE);
263	goldfish_fb_pan_display(&fb->fb.var, &fb->fb); /* updates base */
264
265	ret = register_framebuffer(&fb->fb);
266	if (ret)
267		goto err_register_framebuffer_failed;
268	return 0;
269
270err_register_framebuffer_failed:
271	free_irq(fb->irq, fb);
272err_request_irq_failed:
273err_fb_set_var_failed:
274	dma_free_coherent(&pdev->dev, framesize,
275				(void *)fb->fb.screen_base,
276				fb->fb.fix.smem_start);
277err_alloc_screen_base_failed:
278err_no_irq:
279	iounmap(fb->reg_base);
280err_no_io_base:
281	kfree(fb);
282err_fb_alloc_failed:
283	return ret;
284}
285
286static int goldfish_fb_remove(struct platform_device *pdev)
287{
288	size_t framesize;
289	struct goldfish_fb *fb = platform_get_drvdata(pdev);
290
291	framesize = fb->fb.var.xres_virtual * fb->fb.var.yres_virtual * 2;
292	unregister_framebuffer(&fb->fb);
293	free_irq(fb->irq, fb);
294
295	dma_free_coherent(&pdev->dev, framesize, (void *)fb->fb.screen_base,
296						fb->fb.fix.smem_start);
297	iounmap(fb->reg_base);
298	kfree(fb);
299	return 0;
300}
301
302static const struct of_device_id goldfish_fb_of_match[] = {
303	{ .compatible = "google,goldfish-fb", },
304	{},
305};
306MODULE_DEVICE_TABLE(of, goldfish_fb_of_match);
307
308static const struct acpi_device_id goldfish_fb_acpi_match[] = {
309	{ "GFSH0004", 0 },
310	{ },
311};
312MODULE_DEVICE_TABLE(acpi, goldfish_fb_acpi_match);
313
314static struct platform_driver goldfish_fb_driver = {
315	.probe		= goldfish_fb_probe,
316	.remove		= goldfish_fb_remove,
317	.driver = {
318		.name = "goldfish_fb",
319		.of_match_table = goldfish_fb_of_match,
320		.acpi_match_table = ACPI_PTR(goldfish_fb_acpi_match),
321	}
322};
323
324module_platform_driver(goldfish_fb_driver);
325
326MODULE_LICENSE("GPL v2");
327