I'm aware of the drm-fbdev resolution, but CONFIG_DRM adds 100kb, which
is a complete blocker on a system with 8mb RAM.
Signed-off-by: Lauri Kasanen <cand@xxxxxxx>
---
arch/mips/n64/init.c | 10 +++
drivers/video/fbdev/Kconfig | 9 ++
drivers/video/fbdev/Makefile | 1 +
drivers/video/fbdev/n64rdp.c | 190 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 210 insertions(+)
create mode 100644 drivers/video/fbdev/n64rdp.c
diff --git a/arch/mips/n64/init.c b/arch/mips/n64/init.c
index 6fb622d..635e9ef 100644
--- a/arch/mips/n64/init.c
+++ b/arch/mips/n64/init.c
@@ -8,6 +8,7 @@
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/memblock.h>
+#include <linux/platform_device.h>
#include <linux/string.h>
#include <asm/bootinfo.h>
@@ -46,6 +47,15 @@ void __init prom_free_prom_memory(void)
{
}
+static int __init n64_platform_init(void)
+{
+ platform_device_register_simple("n64rdp", -1, NULL, 0);
+
+ return 0;
+}
+
+arch_initcall(n64_platform_init);
+
void __init plat_mem_setup(void)
{
iomem_resource_init();
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index cfb7f56..4dde2c7 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -2206,6 +2206,15 @@ config FB_SIMPLE
Configuration re: surface address, size, and format must be provided
through device tree, or plain old platform data.
+config FB_N64RDP
+ bool "Nintendo 64 RDP support"
+ depends on (FB = y) && MIPS_N64
+ select FB_CFB_FILLRECT
+ select FB_CFB_COPYAREA
+ select FB_CFB_IMAGEBLIT
+ help
+ Driver for the N64's display.
+
config FB_SSD1307
tristate "Solomon SSD1307 framebuffer support"
depends on FB && I2C
diff --git a/drivers/video/fbdev/Makefile b/drivers/video/fbdev/Makefile
index 477b962..86f1e22 100644
--- a/drivers/video/fbdev/Makefile
+++ b/drivers/video/fbdev/Makefile
@@ -129,6 +129,7 @@ obj-$(CONFIG_FB_MX3) += mx3fb.o
obj-$(CONFIG_FB_DA8XX) += da8xx-fb.o
obj-$(CONFIG_FB_SSD1307) += ssd1307fb.o
obj-$(CONFIG_FB_SIMPLE) += simplefb.o
+obj-$(CONFIG_FB_N64RDP) += n64rdp.o
# the test framebuffer is last
obj-$(CONFIG_FB_VIRTUAL) += vfb.o
diff --git a/drivers/video/fbdev/n64rdp.c b/drivers/video/fbdev/n64rdp.c
new file mode 100644
index 0000000..e5456b6
--- /dev/null
+++ b/drivers/video/fbdev/n64rdp.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * DRM driver for the N64's RDP
+ *
+ * Copyright (c) 2020 Lauri Kasanen
+ *
+ * Based on simplefb.c, which was:
+ * Copyright (c) 2013, Stephen Warren
+ *
+ * Based on q40fb.c, which was:
+ * Copyright (C) 2001 Richard Zidlicky <rz@xxxxxxxxxxxxxx>
+ *
+ * Also based on offb.c, which was:
+ * Copyright (C) 1997 Geert Uytterhoeven
+ * Copyright (C) 1996 Paul Mackerras
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/fb.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/parser.h>
+
+#include <asm/addrspace.h>
+
+static const struct fb_fix_screeninfo n64rdp_fix = {
+ .id = "default",
+ .type = FB_TYPE_PACKED_PIXELS,
+ .visual = FB_VISUAL_TRUECOLOR,
+ .accel = FB_ACCEL_NONE,
+};
+
+static const struct fb_var_screeninfo n64rdp_var = {
+ .height = -1,
+ .width = -1,
+ .activate = FB_ACTIVATE_NOW,
+ .vmode = FB_VMODE_NONINTERLACED,
+};
+
+#define PSEUDO_PALETTE_SIZE 16
+
+static int n64rdp_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+ u_int transp, struct fb_info *info)
+{
+ u32 *pal = info->pseudo_palette;
+ u32 cr = red >> (16 - info->var.red.length);
+ u32 cg = green >> (16 - info->var.green.length);
+ u32 cb = blue >> (16 - info->var.blue.length);
+ u32 value;
+
+ if (regno >= PSEUDO_PALETTE_SIZE)
+ return -EINVAL;
+
+ value = (cr << info->var.red.offset) |
+ (cg << info->var.green.offset) |
+ (cb << info->var.blue.offset);
+ if (info->var.transp.length > 0) {
+ u32 mask = (1 << info->var.transp.length) - 1;
+ mask <<= info->var.transp.offset;
+ value |= mask;
+ }
+ pal[regno] = value;
+
+ return 0;
+}
+
+static const struct fb_ops n64rdp_ops = {
+ .owner = THIS_MODULE,
+ .fb_setcolreg = n64rdp_setcolreg,
+ .fb_fillrect = cfb_fillrect,
+ .fb_copyarea = cfb_copyarea,
+ .fb_imageblit = cfb_imageblit,
+};
+
+struct n64rdp_par {
+ u32 palette[PSEUDO_PALETTE_SIZE];
+ dma_addr_t physaddr;
+};
+
+#define REG_BASE ((u32 *) CKSEG1ADDR(0xA4400000))
+
+static void n64rdp_write_reg(const u8 reg, const u32 value)
+{
+ __raw_writel(value, REG_BASE + reg);
+}
+
+#define W 320
+#define H 240
+
+static const u32 ntsc_320[] __initconst = {
+ 0x00013212, 0x00000000, 0x00000140, 0x00000200,
+ 0x00000000, 0x03e52239, 0x0000020d, 0x00000c15,
+ 0x0c150c15, 0x006c02ec, 0x002501ff, 0x000e0204,
+ 0x00000200, 0x00000400
+};
+
+static int __init n64rdp_probe(struct platform_device *pdev)
+{
+ int ret;
+ u32 i;
+ struct fb_info *info;
+ struct n64rdp_par *par;
+ dma_addr_t addr;
+
+ info = framebuffer_alloc(sizeof(struct n64rdp_par), &pdev->dev);
+ if (!info)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, info);
+
+ par = info->par;
+
+ info->fix = n64rdp_fix;
+ info->screen_base = dma_alloc_coherent(&pdev->dev, W * H * 2, &addr,
+ GFP_DMA | GFP_KERNEL);
+ if (!info->screen_base)
+ return -ENOMEM;
+
+ info->fix.smem_start = par->physaddr = addr;
+ info->fix.smem_len = W * H * 2;
+ info->fix.line_length = W * 2;
+
+ info->var = n64rdp_var;
+ info->var.xres = W;
+ info->var.yres = H;
+ info->var.xres_virtual = W;
+ info->var.yres_virtual = H;
+ info->var.bits_per_pixel = 16;
+ info->var.red = (struct fb_bitfield) {11, 5};
+ info->var.green = (struct fb_bitfield) {6, 5};
+ info->var.blue = (struct fb_bitfield) {1, 5};
+ info->var.transp = (struct fb_bitfield) {0, 1};
+
+ info->apertures = alloc_apertures(1);
+ if (!info->apertures) {
+ ret = -ENOMEM;
+ goto error_fb_release;
+ }
+ info->apertures->ranges[0].base = info->fix.smem_start;
+ info->apertures->ranges[0].size = info->fix.smem_len;
+
+ info->fbops = &n64rdp_ops;
+ info->flags = FBINFO_DEFAULT;
+ info->pseudo_palette = par->palette;
+
+ dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n",
+ info->fix.smem_start, info->fix.smem_len,
+ info->screen_base);
+
+ ret = register_framebuffer(info);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Unable to register n64rdp: %d\n", ret);
+ goto error_fb_release;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(ntsc_320); i++) {
+ if (i == 1)
+ n64rdp_write_reg(i, par->physaddr);
+ else
+ n64rdp_write_reg(i, ntsc_320[i]);
+ }
+
+ return 0;
+
+error_fb_release:
+ framebuffer_release(info);
+ return ret;
+}
+
+static struct platform_driver n64rdp_driver = {
+ .driver = {
+ .name = "n64rdp",
+ },
+};
+
+static int __init n64rdp_init(void)
+{
+ int ret;
+
+ ret = platform_driver_probe(&n64rdp_driver, n64rdp_probe);
+
+ return ret;
+}
+
+fs_initcall(n64rdp_init);
+
+MODULE_AUTHOR("Lauri Kasanen <cand@xxxxxxx>");
+MODULE_DESCRIPTION("Driver for the N64's display");
+MODULE_LICENSE("GPL v2");
--
2.6.2
