568 lines
14 KiB
C
568 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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u32 palette[PSEUDO_PALETTE_SIZE];
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struct resource *mem;
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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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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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/*
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* fb_ops.fb_destroy is called by the last put_fb_info() call at the end
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* of unregister_framebuffer() or fb_release(). Do any cleanup here.
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*/
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static void simplefb_destroy(struct fb_info *info)
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{
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struct simplefb_par *par = info->par;
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struct resource *mem = par->mem;
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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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framebuffer_release(info);
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if (mem)
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release_mem_region(mem->start, resource_size(mem));
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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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#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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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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strscpy(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 *res, *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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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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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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mem = request_mem_region(res->start, resource_size(res), "simplefb");
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if (!mem) {
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/*
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* We cannot make this fatal. Sometimes this comes from magic
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* spaces our resource handlers simply don't know about. Use
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* the I/O-memory resource as-is and try to map that instead.
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*/
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dev_warn(&pdev->dev, "simplefb: cannot reserve video memory at %pR\n", res);
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mem = res;
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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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ret = -ENOMEM;
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goto error_release_mem_region;
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}
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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\n",
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info->fix.smem_start, info->fix.smem_len);
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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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if (mem != res)
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par->mem = mem; /* release in clean-up handler */
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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);
|
|
goto error_regulators;
|
|
}
|
|
|
|
dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node);
|
|
|
|
return 0;
|
|
|
|
error_regulators:
|
|
simplefb_regulators_destroy(par);
|
|
error_clocks:
|
|
simplefb_clocks_destroy(par);
|
|
error_unmap:
|
|
iounmap(info->screen_base);
|
|
error_fb_release:
|
|
framebuffer_release(info);
|
|
error_release_mem_region:
|
|
if (mem != res)
|
|
release_mem_region(mem->start, resource_size(mem));
|
|
return ret;
|
|
}
|
|
|
|
static int simplefb_remove(struct platform_device *pdev)
|
|
{
|
|
struct fb_info *info = platform_get_drvdata(pdev);
|
|
|
|
/* simplefb_destroy takes care of info cleanup */
|
|
unregister_framebuffer(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,
|
|
};
|
|
|
|
module_platform_driver(simplefb_driver);
|
|
|
|
MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
|
|
MODULE_DESCRIPTION("Simple framebuffer driver");
|
|
MODULE_LICENSE("GPL v2");
|