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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 if (!wait_event_timeout(fb->wait,
142 fb->base_update_count != base_update_count,
143 HZ / 15)) {
144 pr_err("%s: timeout waiting for base update\n", __func__);
145 return -ETIMEDOUT;
146 }
147 return 0;
148}
149
150static int goldfish_fb_blank(int blank, struct fb_info *info)
151{
152 struct goldfish_fb *fb = container_of(info, struct goldfish_fb, fb);
153
154 switch (blank) {
155 case FB_BLANK_NORMAL:
156 writel(1, fb->reg_base + FB_SET_BLANK);
157 break;
158 case FB_BLANK_UNBLANK:
159 writel(0, fb->reg_base + FB_SET_BLANK);
160 break;
161 }
162 return 0;
163}
164
165static const struct fb_ops goldfish_fb_ops = {
166 .owner = THIS_MODULE,
167 FB_DEFAULT_IOMEM_OPS,
168 .fb_check_var = goldfish_fb_check_var,
169 .fb_set_par = goldfish_fb_set_par,
170 .fb_setcolreg = goldfish_fb_setcolreg,
171 .fb_pan_display = goldfish_fb_pan_display,
172 .fb_blank = goldfish_fb_blank,
173};
174
175
176static int goldfish_fb_probe(struct platform_device *pdev)
177{
178 int ret;
179 struct goldfish_fb *fb;
180 size_t framesize;
181 u32 width, height;
182 dma_addr_t fbpaddr;
183
184 fb = kzalloc_obj(*fb);
185 if (fb == NULL) {
186 ret = -ENOMEM;
187 goto err_fb_alloc_failed;
188 }
189 spin_lock_init(&fb->lock);
190 init_waitqueue_head(&fb->wait);
191 platform_set_drvdata(pdev, fb);
192
193 fb->reg_base = devm_platform_ioremap_resource(pdev, 0);
194 if (IS_ERR(fb->reg_base)) {
195 ret = PTR_ERR(fb->reg_base);
196 goto err_no_io_base;
197 }
198
199 fb->irq = platform_get_irq(pdev, 0);
200 if (fb->irq < 0) {
201 ret = fb->irq;
202 goto err_no_irq;
203 }
204
205 width = readl(fb->reg_base + FB_GET_WIDTH);
206 height = readl(fb->reg_base + FB_GET_HEIGHT);
207
208 fb->fb.fbops = &goldfish_fb_ops;
209 fb->fb.pseudo_palette = fb->cmap;
210 fb->fb.fix.type = FB_TYPE_PACKED_PIXELS;
211 fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
212 fb->fb.fix.line_length = width * 2;
213 fb->fb.fix.accel = FB_ACCEL_NONE;
214 fb->fb.fix.ypanstep = 1;
215
216 fb->fb.var.xres = width;
217 fb->fb.var.yres = height;
218 fb->fb.var.xres_virtual = width;
219 fb->fb.var.yres_virtual = height * 2;
220 fb->fb.var.bits_per_pixel = 16;
221 fb->fb.var.activate = FB_ACTIVATE_NOW;
222 fb->fb.var.height = readl(fb->reg_base + FB_GET_PHYS_HEIGHT);
223 fb->fb.var.width = readl(fb->reg_base + FB_GET_PHYS_WIDTH);
224 fb->fb.var.pixclock = 0;
225
226 fb->fb.var.red.offset = 11;
227 fb->fb.var.red.length = 5;
228 fb->fb.var.green.offset = 5;
229 fb->fb.var.green.length = 6;
230 fb->fb.var.blue.offset = 0;
231 fb->fb.var.blue.length = 5;
232
233 framesize = width * height * 2 * 2;
234 fb->fb.screen_base = (char __force __iomem *)dma_alloc_coherent(
235 &pdev->dev, framesize,
236 &fbpaddr, GFP_KERNEL);
237 pr_debug("allocating frame buffer %d * %d, got %p\n",
238 width, height, fb->fb.screen_base);
239 if (fb->fb.screen_base == NULL) {
240 ret = -ENOMEM;
241 goto err_alloc_screen_base_failed;
242 }
243 fb->fb.fix.smem_start = fbpaddr;
244 fb->fb.fix.smem_len = framesize;
245
246 ret = fb_set_var(&fb->fb, &fb->fb.var);
247 if (ret)
248 goto err_fb_set_var_failed;
249
250 ret = request_irq(fb->irq, goldfish_fb_interrupt, IRQF_SHARED,
251 pdev->name, fb);
252 if (ret)
253 goto err_request_irq_failed;
254
255 writel(FB_INT_BASE_UPDATE_DONE, fb->reg_base + FB_INT_ENABLE);
256 ret = goldfish_fb_pan_display(&fb->fb.var, &fb->fb); /* updates base */
257 if (ret)
258 goto err_pan_display_failed;
259
260 ret = register_framebuffer(&fb->fb);
261 if (ret)
262 goto err_register_framebuffer_failed;
263 return 0;
264
265err_register_framebuffer_failed:
266err_pan_display_failed:
267 free_irq(fb->irq, fb);
268err_request_irq_failed:
269err_fb_set_var_failed:
270 dma_free_coherent(&pdev->dev, framesize,
271 (void *)fb->fb.screen_base,
272 fb->fb.fix.smem_start);
273err_alloc_screen_base_failed:
274err_no_irq:
275err_no_io_base:
276 kfree(fb);
277err_fb_alloc_failed:
278 return ret;
279}
280
281static void goldfish_fb_remove(struct platform_device *pdev)
282{
283 size_t framesize;
284 struct goldfish_fb *fb = platform_get_drvdata(pdev);
285
286 framesize = fb->fb.var.xres_virtual * fb->fb.var.yres_virtual * 2;
287 unregister_framebuffer(&fb->fb);
288 free_irq(fb->irq, fb);
289
290 dma_free_coherent(&pdev->dev, framesize, (void *)fb->fb.screen_base,
291 fb->fb.fix.smem_start);
292 kfree(fb);
293}
294
295static const struct of_device_id goldfish_fb_of_match[] = {
296 { .compatible = "google,goldfish-fb", },
297 {},
298};
299MODULE_DEVICE_TABLE(of, goldfish_fb_of_match);
300
301#ifdef CONFIG_ACPI
302static const struct acpi_device_id goldfish_fb_acpi_match[] = {
303 { "GFSH0004", 0 },
304 { },
305};
306MODULE_DEVICE_TABLE(acpi, goldfish_fb_acpi_match);
307#endif
308
309static struct platform_driver goldfish_fb_driver = {
310 .probe = goldfish_fb_probe,
311 .remove = goldfish_fb_remove,
312 .driver = {
313 .name = "goldfish_fb",
314 .of_match_table = goldfish_fb_of_match,
315 .acpi_match_table = ACPI_PTR(goldfish_fb_acpi_match),
316 }
317};
318
319module_platform_driver(goldfish_fb_driver);
320
321MODULE_DESCRIPTION("Goldfish Virtual Platform Framebuffer driver");
322MODULE_LICENSE("GPL v2");