linux/drivers/video/goldfishfb.c
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   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
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