![Jani Nikula](/assets/img/avatar_default.png)
Now that the fbops member of struct fb_info is const, we can start making the ops const as well. This does not cover all drivers; some actually modify the fbops struct, for example to adjust for different configurations, and others do more involved things that I'd rather not touch in practically obsolete drivers. Mostly this is the low hanging fruit where we can add "const" and be done with it. v3: - un-constify atyfb, mb862xx, nvidia and uvesabf (0day) v2: - fix typo (Christophe de Dinechin) - use "static const" instead of "const static" in mx3fb.c - also constify smscufx.c Cc: linux-fbdev@vger.kernel.org Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/ce67f14435f3af498f2e8bf35ce4be11f7504132.1575390740.git.jani.nikula@intel.com
558 lines
14 KiB
C
558 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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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#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.h>
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#include <linux/of.h>
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#include <linux/of_clk.h>
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#include <linux/of_platform.h>
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#include <linux/parser.h>
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#include <linux/regulator/consumer.h>
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static const 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 const 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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struct simplefb_par;
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static void simplefb_clocks_destroy(struct simplefb_par *par);
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static void simplefb_regulators_destroy(struct simplefb_par *par);
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static void simplefb_destroy(struct fb_info *info)
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{
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simplefb_regulators_destroy(info->par);
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simplefb_clocks_destroy(info->par);
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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 const 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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bool clks_enabled;
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unsigned int clk_count;
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struct clk **clks;
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#endif
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#if defined CONFIG_OF && defined CONFIG_REGULATOR
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bool regulators_enabled;
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u32 regulator_count;
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struct regulator **regulators;
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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_get(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;
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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)
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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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return 0;
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}
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static void simplefb_clocks_enable(struct simplefb_par *par,
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struct platform_device *pdev)
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{
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int i, ret;
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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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par->clks_enabled = true;
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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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if (par->clks_enabled)
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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_get(struct simplefb_par *par,
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struct platform_device *pdev) { return 0; }
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static void simplefb_clocks_enable(struct simplefb_par *par,
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struct platform_device *pdev) { }
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static void simplefb_clocks_destroy(struct simplefb_par *par) { }
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#endif
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#if defined CONFIG_OF && defined CONFIG_REGULATOR
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#define SUPPLY_SUFFIX "-supply"
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/*
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* Regulator handling code.
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*
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* Here we handle the num-supplies and vin*-supply properties of our
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* "simple-framebuffer" dt node. This is necessary so that we can make sure
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* that any regulators needed by the display hardware that the bootloader
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* set up for us (and for which it provided a simplefb dt node), stay up,
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* for the life of the simplefb driver.
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*
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* When the driver unloads, we cleanly disable, and then release the
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* regulators.
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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 regulator 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_regulators_get(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 property *prop;
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struct regulator *regulator;
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const char *p;
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int count = 0, i = 0;
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if (dev_get_platdata(&pdev->dev) || !np)
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return 0;
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/* Count the number of regulator supplies */
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for_each_property_of_node(np, prop) {
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p = strstr(prop->name, SUPPLY_SUFFIX);
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if (p && p != prop->name)
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count++;
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}
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if (!count)
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return 0;
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par->regulators = devm_kcalloc(&pdev->dev, count,
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sizeof(struct regulator *), GFP_KERNEL);
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if (!par->regulators)
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return -ENOMEM;
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/* Get all the regulators */
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for_each_property_of_node(np, prop) {
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char name[32]; /* 32 is max size of property name */
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p = strstr(prop->name, SUPPLY_SUFFIX);
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if (!p || p == prop->name)
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continue;
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strlcpy(name, prop->name,
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strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1);
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regulator = devm_regulator_get_optional(&pdev->dev, name);
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if (IS_ERR(regulator)) {
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if (PTR_ERR(regulator) == -EPROBE_DEFER)
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return -EPROBE_DEFER;
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dev_err(&pdev->dev, "regulator %s not found: %ld\n",
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name, PTR_ERR(regulator));
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continue;
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}
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par->regulators[i++] = regulator;
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}
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par->regulator_count = i;
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return 0;
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}
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static void simplefb_regulators_enable(struct simplefb_par *par,
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struct platform_device *pdev)
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{
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int i, ret;
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/* Enable all the regulators */
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for (i = 0; i < par->regulator_count; i++) {
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ret = regulator_enable(par->regulators[i]);
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if (ret) {
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dev_err(&pdev->dev,
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"failed to enable regulator %d: %d\n",
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i, ret);
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devm_regulator_put(par->regulators[i]);
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par->regulators[i] = NULL;
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}
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}
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par->regulators_enabled = true;
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}
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static void simplefb_regulators_destroy(struct simplefb_par *par)
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{
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int i;
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if (!par->regulators || !par->regulators_enabled)
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return;
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for (i = 0; i < par->regulator_count; i++)
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if (par->regulators[i])
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regulator_disable(par->regulators[i]);
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}
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#else
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static int simplefb_regulators_get(struct simplefb_par *par,
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struct platform_device *pdev) { return 0; }
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static void simplefb_regulators_enable(struct simplefb_par *par,
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struct platform_device *pdev) { }
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static void simplefb_regulators_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_get(par, pdev);
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if (ret < 0)
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goto error_unmap;
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ret = simplefb_regulators_get(par, pdev);
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if (ret < 0)
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goto error_clocks;
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simplefb_clocks_enable(par, pdev);
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simplefb_regulators_enable(par, pdev);
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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_regulators;
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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_regulators:
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simplefb_regulators_destroy(par);
|
|
error_clocks:
|
|
simplefb_clocks_destroy(par);
|
|
error_unmap:
|
|
iounmap(info->screen_base);
|
|
error_fb_release:
|
|
framebuffer_release(info);
|
|
return ret;
|
|
}
|
|
|
|
static int simplefb_remove(struct platform_device *pdev)
|
|
{
|
|
struct fb_info *info = platform_get_drvdata(pdev);
|
|
|
|
unregister_framebuffer(info);
|
|
framebuffer_release(info);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id simplefb_of_match[] = {
|
|
{ .compatible = "simple-framebuffer", },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, simplefb_of_match);
|
|
|
|
static struct platform_driver simplefb_driver = {
|
|
.driver = {
|
|
.name = "simple-framebuffer",
|
|
.of_match_table = simplefb_of_match,
|
|
},
|
|
.probe = simplefb_probe,
|
|
.remove = simplefb_remove,
|
|
};
|
|
|
|
static int __init simplefb_init(void)
|
|
{
|
|
int ret;
|
|
struct device_node *np;
|
|
|
|
ret = platform_driver_register(&simplefb_driver);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (IS_ENABLED(CONFIG_OF_ADDRESS) && of_chosen) {
|
|
for_each_child_of_node(of_chosen, np) {
|
|
if (of_device_is_compatible(np, "simple-framebuffer"))
|
|
of_platform_device_create(np, NULL, NULL);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(simplefb_init);
|
|
|
|
MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
|
|
MODULE_DESCRIPTION("Simple framebuffer driver");
|
|
MODULE_LICENSE("GPL v2");
|