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
22 enum {
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
37 struct 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
goldfish_fb_interrupt(int irq,void * dev_id)48 static 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
convert_bitfield(int val,struct fb_bitfield * bf)64 static 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
71 static int
goldfish_fb_setcolreg(unsigned int regno,unsigned int red,unsigned int green,unsigned int blue,unsigned int transp,struct fb_info * info)72 goldfish_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
goldfish_fb_check_var(struct fb_var_screeninfo * var,struct fb_info * info)88 static 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
goldfish_fb_set_par(struct fb_info * info)116 static 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
goldfish_fb_pan_display(struct fb_var_screeninfo * var,struct fb_info * info)129 static 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
goldfish_fb_blank(int blank,struct fb_info * info)148 static 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
163 static const struct fb_ops goldfish_fb_ops = {
164 .owner = THIS_MODULE,
165 FB_DEFAULT_IOMEM_OPS,
166 .fb_check_var = goldfish_fb_check_var,
167 .fb_set_par = goldfish_fb_set_par,
168 .fb_setcolreg = goldfish_fb_setcolreg,
169 .fb_pan_display = goldfish_fb_pan_display,
170 .fb_blank = goldfish_fb_blank,
171 };
172
173
goldfish_fb_probe(struct platform_device * pdev)174 static int goldfish_fb_probe(struct platform_device *pdev)
175 {
176 int ret;
177 struct resource *r;
178 struct goldfish_fb *fb;
179 size_t framesize;
180 u32 width, height;
181 dma_addr_t fbpaddr;
182
183 fb = kzalloc(sizeof(*fb), GFP_KERNEL);
184 if (fb == NULL) {
185 ret = -ENOMEM;
186 goto err_fb_alloc_failed;
187 }
188 spin_lock_init(&fb->lock);
189 init_waitqueue_head(&fb->wait);
190 platform_set_drvdata(pdev, fb);
191
192 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
193 if (r == NULL) {
194 ret = -ENODEV;
195 goto err_no_io_base;
196 }
197 fb->reg_base = ioremap(r->start, PAGE_SIZE);
198 if (fb->reg_base == NULL) {
199 ret = -ENOMEM;
200 goto err_no_io_base;
201 }
202
203 fb->irq = platform_get_irq(pdev, 0);
204 if (fb->irq < 0) {
205 ret = fb->irq;
206 goto err_no_irq;
207 }
208
209 width = readl(fb->reg_base + FB_GET_WIDTH);
210 height = readl(fb->reg_base + FB_GET_HEIGHT);
211
212 fb->fb.fbops = &goldfish_fb_ops;
213 fb->fb.pseudo_palette = fb->cmap;
214 fb->fb.fix.type = FB_TYPE_PACKED_PIXELS;
215 fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
216 fb->fb.fix.line_length = width * 2;
217 fb->fb.fix.accel = FB_ACCEL_NONE;
218 fb->fb.fix.ypanstep = 1;
219
220 fb->fb.var.xres = width;
221 fb->fb.var.yres = height;
222 fb->fb.var.xres_virtual = width;
223 fb->fb.var.yres_virtual = height * 2;
224 fb->fb.var.bits_per_pixel = 16;
225 fb->fb.var.activate = FB_ACTIVATE_NOW;
226 fb->fb.var.height = readl(fb->reg_base + FB_GET_PHYS_HEIGHT);
227 fb->fb.var.width = readl(fb->reg_base + FB_GET_PHYS_WIDTH);
228 fb->fb.var.pixclock = 0;
229
230 fb->fb.var.red.offset = 11;
231 fb->fb.var.red.length = 5;
232 fb->fb.var.green.offset = 5;
233 fb->fb.var.green.length = 6;
234 fb->fb.var.blue.offset = 0;
235 fb->fb.var.blue.length = 5;
236
237 framesize = width * height * 2 * 2;
238 fb->fb.screen_base = (char __force __iomem *)dma_alloc_coherent(
239 &pdev->dev, framesize,
240 &fbpaddr, GFP_KERNEL);
241 pr_debug("allocating frame buffer %d * %d, got %p\n",
242 width, height, fb->fb.screen_base);
243 if (fb->fb.screen_base == NULL) {
244 ret = -ENOMEM;
245 goto err_alloc_screen_base_failed;
246 }
247 fb->fb.fix.smem_start = fbpaddr;
248 fb->fb.fix.smem_len = framesize;
249
250 ret = fb_set_var(&fb->fb, &fb->fb.var);
251 if (ret)
252 goto err_fb_set_var_failed;
253
254 ret = request_irq(fb->irq, goldfish_fb_interrupt, IRQF_SHARED,
255 pdev->name, fb);
256 if (ret)
257 goto err_request_irq_failed;
258
259 writel(FB_INT_BASE_UPDATE_DONE, fb->reg_base + FB_INT_ENABLE);
260 goldfish_fb_pan_display(&fb->fb.var, &fb->fb); /* updates base */
261
262 ret = register_framebuffer(&fb->fb);
263 if (ret)
264 goto err_register_framebuffer_failed;
265 return 0;
266
267 err_register_framebuffer_failed:
268 free_irq(fb->irq, fb);
269 err_request_irq_failed:
270 err_fb_set_var_failed:
271 dma_free_coherent(&pdev->dev, framesize,
272 (void *)fb->fb.screen_base,
273 fb->fb.fix.smem_start);
274 err_alloc_screen_base_failed:
275 err_no_irq:
276 iounmap(fb->reg_base);
277 err_no_io_base:
278 kfree(fb);
279 err_fb_alloc_failed:
280 return ret;
281 }
282
goldfish_fb_remove(struct platform_device * pdev)283 static void goldfish_fb_remove(struct platform_device *pdev)
284 {
285 size_t framesize;
286 struct goldfish_fb *fb = platform_get_drvdata(pdev);
287
288 framesize = fb->fb.var.xres_virtual * fb->fb.var.yres_virtual * 2;
289 unregister_framebuffer(&fb->fb);
290 free_irq(fb->irq, fb);
291
292 dma_free_coherent(&pdev->dev, framesize, (void *)fb->fb.screen_base,
293 fb->fb.fix.smem_start);
294 iounmap(fb->reg_base);
295 kfree(fb);
296 }
297
298 static const struct of_device_id goldfish_fb_of_match[] = {
299 { .compatible = "google,goldfish-fb", },
300 {},
301 };
302 MODULE_DEVICE_TABLE(of, goldfish_fb_of_match);
303
304 #ifdef CONFIG_ACPI
305 static const struct acpi_device_id goldfish_fb_acpi_match[] = {
306 { "GFSH0004", 0 },
307 { },
308 };
309 MODULE_DEVICE_TABLE(acpi, goldfish_fb_acpi_match);
310 #endif
311
312 static struct platform_driver goldfish_fb_driver = {
313 .probe = goldfish_fb_probe,
314 .remove = goldfish_fb_remove,
315 .driver = {
316 .name = "goldfish_fb",
317 .of_match_table = goldfish_fb_of_match,
318 .acpi_match_table = ACPI_PTR(goldfish_fb_acpi_match),
319 }
320 };
321
322 module_platform_driver(goldfish_fb_driver);
323
324 MODULE_DESCRIPTION("Goldfish Virtual Platform Framebuffer driver");
325 MODULE_LICENSE("GPL v2");
326