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path: root/drivers/firmware/google/framebuffer-coreboot.c
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Diffstat (limited to 'drivers/firmware/google/framebuffer-coreboot.c')
-rw-r--r--drivers/firmware/google/framebuffer-coreboot.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/firmware/google/framebuffer-coreboot.c b/drivers/firmware/google/framebuffer-coreboot.c
new file mode 100644
index 000000000..c323a8188
--- /dev/null
+++ b/drivers/firmware/google/framebuffer-coreboot.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * framebuffer-coreboot.c
+ *
+ * Memory based framebuffer accessed through coreboot table.
+ *
+ * Copyright 2012-2013 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright 2017 Google Inc.
+ * Copyright 2017 Samuel Holland <samuel@sholland.org>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/platform_data/simplefb.h>
+#include <linux/platform_device.h>
+
+#include "coreboot_table.h"
+
+#define CB_TAG_FRAMEBUFFER 0x12
+
+static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;
+
+static int framebuffer_probe(struct coreboot_device *dev)
+{
+ int i;
+ u32 length;
+ struct lb_framebuffer *fb = &dev->framebuffer;
+ struct platform_device *pdev;
+ struct resource res;
+ struct simplefb_platform_data pdata = {
+ .width = fb->x_resolution,
+ .height = fb->y_resolution,
+ .stride = fb->bytes_per_line,
+ .format = NULL,
+ };
+
+ for (i = 0; i < ARRAY_SIZE(formats); ++i) {
+ if (fb->bits_per_pixel == formats[i].bits_per_pixel &&
+ fb->red_mask_pos == formats[i].red.offset &&
+ fb->red_mask_size == formats[i].red.length &&
+ fb->green_mask_pos == formats[i].green.offset &&
+ fb->green_mask_size == formats[i].green.length &&
+ fb->blue_mask_pos == formats[i].blue.offset &&
+ fb->blue_mask_size == formats[i].blue.length)
+ pdata.format = formats[i].name;
+ }
+ if (!pdata.format)
+ return -ENODEV;
+
+ memset(&res, 0, sizeof(res));
+ res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+ res.name = "Coreboot Framebuffer";
+ res.start = fb->physical_address;
+ length = PAGE_ALIGN(fb->y_resolution * fb->bytes_per_line);
+ res.end = res.start + length - 1;
+ if (res.end <= res.start)
+ return -EINVAL;
+
+ pdev = platform_device_register_resndata(&dev->dev,
+ "simple-framebuffer", 0,
+ &res, 1, &pdata,
+ sizeof(pdata));
+ if (IS_ERR(pdev))
+ pr_warn("coreboot: could not register framebuffer\n");
+ else
+ dev_set_drvdata(&dev->dev, pdev);
+
+ return PTR_ERR_OR_ZERO(pdev);
+}
+
+static void framebuffer_remove(struct coreboot_device *dev)
+{
+ struct platform_device *pdev = dev_get_drvdata(&dev->dev);
+
+ platform_device_unregister(pdev);
+}
+
+static struct coreboot_driver framebuffer_driver = {
+ .probe = framebuffer_probe,
+ .remove = framebuffer_remove,
+ .drv = {
+ .name = "framebuffer",
+ },
+ .tag = CB_TAG_FRAMEBUFFER,
+};
+module_coreboot_driver(framebuffer_driver);
+
+MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
+MODULE_LICENSE("GPL");