mirror of https://gitee.com/openkylin/linux.git
421 lines
10 KiB
C
421 lines
10 KiB
C
/*
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* Simplest possible simple frame-buffer driver, as a platform device
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*
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* Copyright (c) 2013, Stephen Warren
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*
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* Based on q40fb.c, which was:
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* Copyright (C) 2001 Richard Zidlicky <rz@linux-m68k.org>
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*
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* Also based on offb.c, which was:
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* Copyright (C) 1997 Geert Uytterhoeven
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* Copyright (C) 1996 Paul Mackerras
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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#include <linux/errno.h>
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#include <linux/fb.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/platform_data/simplefb.h>
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#include <linux/platform_device.h>
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#include <linux/clk-provider.h>
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#include <linux/of_platform.h>
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static struct fb_fix_screeninfo simplefb_fix = {
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.id = "simple",
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.type = FB_TYPE_PACKED_PIXELS,
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.visual = FB_VISUAL_TRUECOLOR,
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.accel = FB_ACCEL_NONE,
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};
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static struct fb_var_screeninfo simplefb_var = {
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.height = -1,
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.width = -1,
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.activate = FB_ACTIVATE_NOW,
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.vmode = FB_VMODE_NONINTERLACED,
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};
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#define PSEUDO_PALETTE_SIZE 16
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static int simplefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
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u_int transp, struct fb_info *info)
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{
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u32 *pal = info->pseudo_palette;
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u32 cr = red >> (16 - info->var.red.length);
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u32 cg = green >> (16 - info->var.green.length);
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u32 cb = blue >> (16 - info->var.blue.length);
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u32 value;
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if (regno >= PSEUDO_PALETTE_SIZE)
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return -EINVAL;
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value = (cr << info->var.red.offset) |
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(cg << info->var.green.offset) |
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(cb << info->var.blue.offset);
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if (info->var.transp.length > 0) {
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u32 mask = (1 << info->var.transp.length) - 1;
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mask <<= info->var.transp.offset;
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value |= mask;
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}
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pal[regno] = value;
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return 0;
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}
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static void simplefb_destroy(struct fb_info *info)
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{
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if (info->screen_base)
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iounmap(info->screen_base);
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}
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static struct fb_ops simplefb_ops = {
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.owner = THIS_MODULE,
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.fb_destroy = simplefb_destroy,
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.fb_setcolreg = simplefb_setcolreg,
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.fb_fillrect = cfb_fillrect,
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.fb_copyarea = cfb_copyarea,
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.fb_imageblit = cfb_imageblit,
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};
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static struct simplefb_format simplefb_formats[] = SIMPLEFB_FORMATS;
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struct simplefb_params {
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u32 width;
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u32 height;
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u32 stride;
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struct simplefb_format *format;
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};
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static int simplefb_parse_dt(struct platform_device *pdev,
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struct simplefb_params *params)
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{
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struct device_node *np = pdev->dev.of_node;
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int ret;
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const char *format;
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int i;
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ret = of_property_read_u32(np, "width", ¶ms->width);
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if (ret) {
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dev_err(&pdev->dev, "Can't parse width property\n");
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return ret;
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}
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ret = of_property_read_u32(np, "height", ¶ms->height);
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if (ret) {
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dev_err(&pdev->dev, "Can't parse height property\n");
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return ret;
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}
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ret = of_property_read_u32(np, "stride", ¶ms->stride);
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if (ret) {
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dev_err(&pdev->dev, "Can't parse stride property\n");
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return ret;
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}
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ret = of_property_read_string(np, "format", &format);
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if (ret) {
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dev_err(&pdev->dev, "Can't parse format property\n");
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return ret;
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}
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params->format = NULL;
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for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {
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if (strcmp(format, simplefb_formats[i].name))
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continue;
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params->format = &simplefb_formats[i];
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break;
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}
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if (!params->format) {
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dev_err(&pdev->dev, "Invalid format value\n");
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return -EINVAL;
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}
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return 0;
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}
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static int simplefb_parse_pd(struct platform_device *pdev,
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struct simplefb_params *params)
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{
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struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);
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int i;
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params->width = pd->width;
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params->height = pd->height;
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params->stride = pd->stride;
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params->format = NULL;
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for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {
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if (strcmp(pd->format, simplefb_formats[i].name))
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continue;
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params->format = &simplefb_formats[i];
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break;
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}
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if (!params->format) {
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dev_err(&pdev->dev, "Invalid format value\n");
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return -EINVAL;
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}
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return 0;
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}
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struct simplefb_par {
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u32 palette[PSEUDO_PALETTE_SIZE];
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#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
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int clk_count;
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struct clk **clks;
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#endif
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};
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#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
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/*
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* Clock handling code.
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*
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* Here we handle the clocks property of our "simple-framebuffer" dt node.
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* This is necessary so that we can make sure that any clocks needed by
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* the display engine that the bootloader set up for us (and for which it
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* provided a simplefb dt node), stay up, for the life of the simplefb
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* driver.
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*
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* When the driver unloads, we cleanly disable, and then release the clocks.
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*
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* We only complain about errors here, no action is taken as the most likely
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* error can only happen due to a mismatch between the bootloader which set
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* up simplefb, and the clock definitions in the device tree. Chances are
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* that there are no adverse effects, and if there are, a clean teardown of
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* the fb probe will not help us much either. So just complain and carry on,
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* and hope that the user actually gets a working fb at the end of things.
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*/
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static int simplefb_clocks_init(struct simplefb_par *par,
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struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct clk *clock;
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int i, ret;
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if (dev_get_platdata(&pdev->dev) || !np)
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return 0;
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par->clk_count = of_clk_get_parent_count(np);
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if (par->clk_count <= 0)
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return 0;
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par->clks = kcalloc(par->clk_count, sizeof(struct clk *), GFP_KERNEL);
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if (!par->clks)
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return -ENOMEM;
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for (i = 0; i < par->clk_count; i++) {
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clock = of_clk_get(np, i);
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if (IS_ERR(clock)) {
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if (PTR_ERR(clock) == -EPROBE_DEFER) {
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while (--i >= 0) {
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if (par->clks[i])
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clk_put(par->clks[i]);
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}
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kfree(par->clks);
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return -EPROBE_DEFER;
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}
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dev_err(&pdev->dev, "%s: clock %d not found: %ld\n",
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__func__, i, PTR_ERR(clock));
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continue;
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}
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par->clks[i] = clock;
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}
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for (i = 0; i < par->clk_count; i++) {
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if (par->clks[i]) {
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ret = clk_prepare_enable(par->clks[i]);
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if (ret) {
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dev_err(&pdev->dev,
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"%s: failed to enable clock %d: %d\n",
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__func__, i, ret);
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clk_put(par->clks[i]);
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par->clks[i] = NULL;
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}
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}
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}
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return 0;
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}
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static void simplefb_clocks_destroy(struct simplefb_par *par)
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{
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int i;
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if (!par->clks)
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return;
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for (i = 0; i < par->clk_count; i++) {
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if (par->clks[i]) {
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clk_disable_unprepare(par->clks[i]);
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clk_put(par->clks[i]);
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}
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}
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kfree(par->clks);
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}
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#else
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static int simplefb_clocks_init(struct simplefb_par *par,
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struct platform_device *pdev) { return 0; }
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static void simplefb_clocks_destroy(struct simplefb_par *par) { }
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#endif
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static int simplefb_probe(struct platform_device *pdev)
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{
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int ret;
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struct simplefb_params params;
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struct fb_info *info;
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struct simplefb_par *par;
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struct resource *mem;
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if (fb_get_options("simplefb", NULL))
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return -ENODEV;
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ret = -ENODEV;
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if (dev_get_platdata(&pdev->dev))
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ret = simplefb_parse_pd(pdev, ¶ms);
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else if (pdev->dev.of_node)
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ret = simplefb_parse_dt(pdev, ¶ms);
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if (ret)
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return ret;
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!mem) {
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dev_err(&pdev->dev, "No memory resource\n");
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return -EINVAL;
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}
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info = framebuffer_alloc(sizeof(struct simplefb_par), &pdev->dev);
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if (!info)
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return -ENOMEM;
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platform_set_drvdata(pdev, info);
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par = info->par;
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info->fix = simplefb_fix;
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info->fix.smem_start = mem->start;
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info->fix.smem_len = resource_size(mem);
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info->fix.line_length = params.stride;
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info->var = simplefb_var;
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info->var.xres = params.width;
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info->var.yres = params.height;
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info->var.xres_virtual = params.width;
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info->var.yres_virtual = params.height;
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info->var.bits_per_pixel = params.format->bits_per_pixel;
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info->var.red = params.format->red;
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info->var.green = params.format->green;
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info->var.blue = params.format->blue;
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info->var.transp = params.format->transp;
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info->apertures = alloc_apertures(1);
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if (!info->apertures) {
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ret = -ENOMEM;
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goto error_fb_release;
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}
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info->apertures->ranges[0].base = info->fix.smem_start;
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info->apertures->ranges[0].size = info->fix.smem_len;
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info->fbops = &simplefb_ops;
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info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE;
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info->screen_base = ioremap_wc(info->fix.smem_start,
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info->fix.smem_len);
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if (!info->screen_base) {
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ret = -ENOMEM;
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goto error_fb_release;
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}
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info->pseudo_palette = par->palette;
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ret = simplefb_clocks_init(par, pdev);
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if (ret < 0)
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goto error_unmap;
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dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n",
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info->fix.smem_start, info->fix.smem_len,
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info->screen_base);
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dev_info(&pdev->dev, "format=%s, mode=%dx%dx%d, linelength=%d\n",
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params.format->name,
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info->var.xres, info->var.yres,
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info->var.bits_per_pixel, info->fix.line_length);
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ret = register_framebuffer(info);
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if (ret < 0) {
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dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret);
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goto error_clocks;
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}
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dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node);
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return 0;
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error_clocks:
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simplefb_clocks_destroy(par);
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error_unmap:
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iounmap(info->screen_base);
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error_fb_release:
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framebuffer_release(info);
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return ret;
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}
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static int simplefb_remove(struct platform_device *pdev)
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{
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struct fb_info *info = platform_get_drvdata(pdev);
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struct simplefb_par *par = info->par;
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unregister_framebuffer(info);
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simplefb_clocks_destroy(par);
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framebuffer_release(info);
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return 0;
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}
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static const struct of_device_id simplefb_of_match[] = {
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{ .compatible = "simple-framebuffer", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, simplefb_of_match);
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static struct platform_driver simplefb_driver = {
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.driver = {
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.name = "simple-framebuffer",
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.owner = THIS_MODULE,
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.of_match_table = simplefb_of_match,
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},
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.probe = simplefb_probe,
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.remove = simplefb_remove,
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};
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static int __init simplefb_init(void)
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{
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int ret;
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struct device_node *np;
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ret = platform_driver_register(&simplefb_driver);
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if (ret)
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return ret;
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if (IS_ENABLED(CONFIG_OF) && of_chosen) {
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for_each_child_of_node(of_chosen, np) {
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if (of_device_is_compatible(np, "simple-framebuffer"))
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of_platform_device_create(np, NULL, NULL);
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}
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}
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return 0;
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}
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fs_initcall(simplefb_init);
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MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
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MODULE_DESCRIPTION("Simple framebuffer driver");
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MODULE_LICENSE("GPL v2");
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