From 753375a881caa01112b7cec2c796749154e0bb23 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Tue, 18 Oct 2016 15:33:17 +0100 Subject: [PATCH] efifb: Show framebuffer layout as device attributes Userland sometimes needs to know what the framebuffer configuration was when the firmware was running. This enables us to render localized status strings during firmware updates using the data from the ACPI BGRT table and the protocol described at the url below: https://msdn.microsoft.com/en-us/windows/hardware/drivers/bringup/boot-screen-components This patch also fixes up efifb's printk() usage to use pr_warn() / pr_info() / pr_err() instead. Tested-by: Ard Biesheuvel Signed-off-by: Peter Jones Signed-off-by: Ard Biesheuvel Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20161018143318.15673-8-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar --- drivers/video/fbdev/efifb.c | 59 +++++++++++++++++++++++++++++-------- 1 file changed, 46 insertions(+), 13 deletions(-) diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c index 37a37c4d04cb..8c4dc1e1f94f 100644 --- a/drivers/video/fbdev/efifb.c +++ b/drivers/video/fbdev/efifb.c @@ -118,6 +118,31 @@ static inline bool fb_base_is_valid(void) return false; } +#define efifb_attr_decl(name, fmt) \ +static ssize_t name##_show(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ +{ \ + return sprintf(buf, fmt "\n", (screen_info.lfb_##name)); \ +} \ +static DEVICE_ATTR_RO(name) + +efifb_attr_decl(base, "0x%x"); +efifb_attr_decl(linelength, "%u"); +efifb_attr_decl(height, "%u"); +efifb_attr_decl(width, "%u"); +efifb_attr_decl(depth, "%u"); + +static struct attribute *efifb_attrs[] = { + &dev_attr_base.attr, + &dev_attr_linelength.attr, + &dev_attr_width.attr, + &dev_attr_height.attr, + &dev_attr_depth.attr, + NULL +}; +ATTRIBUTE_GROUPS(efifb); + static int efifb_probe(struct platform_device *dev) { struct fb_info *info; @@ -205,14 +230,13 @@ static int efifb_probe(struct platform_device *dev) } else { /* We cannot make this fatal. Sometimes this comes from magic spaces our resource handlers simply don't know about */ - printk(KERN_WARNING - "efifb: cannot reserve video memory at 0x%lx\n", + pr_warn("efifb: cannot reserve video memory at 0x%lx\n", efifb_fix.smem_start); } info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev); if (!info) { - printk(KERN_ERR "efifb: cannot allocate framebuffer\n"); + pr_err("efifb: cannot allocate framebuffer\n"); err = -ENOMEM; goto err_release_mem; } @@ -230,16 +254,15 @@ static int efifb_probe(struct platform_device *dev) info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len); if (!info->screen_base) { - printk(KERN_ERR "efifb: abort, cannot ioremap video memory " - "0x%x @ 0x%lx\n", + pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n", efifb_fix.smem_len, efifb_fix.smem_start); err = -EIO; goto err_release_fb; } - printk(KERN_INFO "efifb: framebuffer at 0x%lx, using %dk, total %dk\n", + pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n", efifb_fix.smem_start, size_remap/1024, size_total/1024); - printk(KERN_INFO "efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n", + pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n", efifb_defined.xres, efifb_defined.yres, efifb_defined.bits_per_pixel, efifb_fix.line_length, screen_info.pages); @@ -247,7 +270,7 @@ static int efifb_probe(struct platform_device *dev) efifb_defined.xres_virtual = efifb_defined.xres; efifb_defined.yres_virtual = efifb_fix.smem_len / efifb_fix.line_length; - printk(KERN_INFO "efifb: scrolling: redraw\n"); + pr_info("efifb: scrolling: redraw\n"); efifb_defined.yres_virtual = efifb_defined.yres; /* some dummy values for timing to make fbset happy */ @@ -265,7 +288,7 @@ static int efifb_probe(struct platform_device *dev) efifb_defined.transp.offset = screen_info.rsvd_pos; efifb_defined.transp.length = screen_info.rsvd_size; - printk(KERN_INFO "efifb: %s: " + pr_info("efifb: %s: " "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n", "Truecolor", screen_info.rsvd_size, @@ -285,12 +308,19 @@ static int efifb_probe(struct platform_device *dev) info->fix = efifb_fix; info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE; - if ((err = fb_alloc_cmap(&info->cmap, 256, 0)) < 0) { - printk(KERN_ERR "efifb: cannot allocate colormap\n"); + err = sysfs_create_groups(&dev->dev.kobj, efifb_groups); + if (err) { + pr_err("efifb: cannot add sysfs attrs\n"); goto err_unmap; } - if ((err = register_framebuffer(info)) < 0) { - printk(KERN_ERR "efifb: cannot register framebuffer\n"); + err = fb_alloc_cmap(&info->cmap, 256, 0); + if (err < 0) { + pr_err("efifb: cannot allocate colormap\n"); + goto err_groups; + } + err = register_framebuffer(info); + if (err < 0) { + pr_err("efifb: cannot register framebuffer\n"); goto err_fb_dealoc; } fb_info(info, "%s frame buffer device\n", info->fix.id); @@ -298,6 +328,8 @@ static int efifb_probe(struct platform_device *dev) err_fb_dealoc: fb_dealloc_cmap(&info->cmap); +err_groups: + sysfs_remove_groups(&dev->dev.kobj, efifb_groups); err_unmap: iounmap(info->screen_base); err_release_fb: @@ -313,6 +345,7 @@ static int efifb_remove(struct platform_device *pdev) struct fb_info *info = platform_get_drvdata(pdev); unregister_framebuffer(info); + sysfs_remove_groups(&pdev->dev.kobj, efifb_groups); framebuffer_release(info); return 0; -- 2.20.1