video: ARM CLCD: Add DT support

This patch adds basic DT bindings for the PL11x CLCD cells
and make their fbdev driver use them.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

2 files changed, 264 insertions, 0 deletions

diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 4a7098fb32c3..6f451ad34afc 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -280,6 +280,7 @@ config FB_ARMCLCD
         select FB_CFB_FILLRECT
         select FB_CFB_COPYAREA
         select FB_CFB_IMAGEBLIT
+        select VIDEOMODE_HELPERS if OF
         help
           This framebuffer device driver is for the ARM PrimeCell PL110
           Colour LCD controller.  ARM PrimeCells provide the building
diff --git a/drivers/video/fbdev/amba-clcd.c b/drivers/video/fbdev/amba-clcd.c
index 14d6b3793e0a..23b35194dee3 100644
--- a/drivers/video/fbdev/amba-clcd.c
+++ b/drivers/video/fbdev/amba-clcd.c
@@ -26,6 +26,13 @@
 #include <linux/amba/clcd.h>
 #include <linux/clk.h>
 #include <linux/hardirq.h>
+#include <linux/dma-mapping.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_graph.h>
+#include <video/display_timing.h>
+#include <video/of_display_timing.h>
+#include <video/videomode.h>
 
 #include <asm/sizes.h>
 
@@ -543,6 +550,259 @@ static int clcdfb_register(struct clcd_fb *fb)
         return ret;
 }
 
+#ifdef CONFIG_OF
+static int clcdfb_of_get_dpi_panel_mode(struct device_node *node,
+                struct fb_videomode *mode)
+{
+        int err;
+        struct display_timing timing;
+        struct videomode video;
+
+        err = of_get_display_timing(node, "panel-timing", &timing);
+        if (err)
+                return err;
+
+        videomode_from_timing(&timing, &video);
+
+        err = fb_videomode_from_videomode(&video, mode);
+        if (err)
+                return err;
+
+        return 0;
+}
+
+static int clcdfb_snprintf_mode(char *buf, int size, struct fb_videomode *mode)
+{
+        return snprintf(buf, size, "%ux%u@%u", mode->xres, mode->yres,
+                        mode->refresh);
+}
+
+static int clcdfb_of_get_mode(struct device *dev, struct device_node *endpoint,
+                struct fb_videomode *mode)
+{
+        int err;
+        struct device_node *panel;
+        char *name;
+        int len;
+
+        panel = of_graph_get_remote_port_parent(endpoint);
+        if (!panel)
+                return -ENODEV;
+
+        /* Only directly connected DPI panels supported for now */
+        if (of_device_is_compatible(panel, "panel-dpi"))
+                err = clcdfb_of_get_dpi_panel_mode(panel, mode);
+        else
+                err = -ENOENT;
+        if (err)
+                return err;
+
+        len = clcdfb_snprintf_mode(NULL, 0, mode);
+        name = devm_kzalloc(dev, len + 1, GFP_KERNEL);
+        clcdfb_snprintf_mode(name, len + 1, mode);
+        mode->name = name;
+
+        return 0;
+}
+
+static int clcdfb_of_init_tft_panel(struct clcd_fb *fb, u32 r0, u32 g0, u32 b0)
+{
+        static struct {
+                unsigned int part;
+                u32 r0, g0, b0;
+                u32 caps;
+        } panels[] = {
+                { 0x110, 1,  7, 13, CLCD_CAP_5551 },
+                { 0x110, 0,  8, 16, CLCD_CAP_888 },
+                { 0x111, 4, 14, 20, CLCD_CAP_444 },
+                { 0x111, 3, 11, 19, CLCD_CAP_444 | CLCD_CAP_5551 },
+                { 0x111, 3, 10, 19, CLCD_CAP_444 | CLCD_CAP_5551 |
+                                    CLCD_CAP_565 },
+                { 0x111, 0,  8, 16, CLCD_CAP_444 | CLCD_CAP_5551 |
+                                    CLCD_CAP_565 | CLCD_CAP_888 },
+        };
+        int i;
+
+        /* Bypass pixel clock divider, data output on the falling edge */
+        fb->panel->tim2 = TIM2_BCD | TIM2_IPC;
+
+        /* TFT display, vert. comp. interrupt at the start of the back porch */
+        fb->panel->cntl |= CNTL_LCDTFT | CNTL_LCDVCOMP(1);
+
+        fb->panel->caps = 0;
+
+        /* Match the setup with known variants */
+        for (i = 0; i < ARRAY_SIZE(panels) && !fb->panel->caps; i++) {
+                if (amba_part(fb->dev) != panels[i].part)
+                        continue;
+                if (g0 != panels[i].g0)
+                        continue;
+                if (r0 == panels[i].r0 && b0 == panels[i].b0)
+                        fb->panel->caps = panels[i].caps & CLCD_CAP_RGB;
+                if (r0 == panels[i].b0 && b0 == panels[i].r0)
+                        fb->panel->caps = panels[i].caps & CLCD_CAP_BGR;
+        }
+
+        return fb->panel->caps ? 0 : -EINVAL;
+}
+
+static int clcdfb_of_init_display(struct clcd_fb *fb)
+{
+        struct device_node *endpoint;
+        int err;
+        u32 max_bandwidth;
+        u32 tft_r0b0g0[3];
+
+        fb->panel = devm_kzalloc(&fb->dev->dev, sizeof(*fb->panel), GFP_KERNEL);
+        if (!fb->panel)
+                return -ENOMEM;
+
+        endpoint = of_graph_get_next_endpoint(fb->dev->dev.of_node, NULL);
+        if (!endpoint)
+                return -ENODEV;
+
+        err = clcdfb_of_get_mode(&fb->dev->dev, endpoint, &fb->panel->mode);
+        if (err)
+                return err;
+
+        err = of_property_read_u32(fb->dev->dev.of_node, "max-memory-bandwidth",
+                        &max_bandwidth);
+        if (!err)
+                fb->panel->bpp = 8 * max_bandwidth / (fb->panel->mode.xres *
+                                fb->panel->mode.yres * fb->panel->mode.refresh);
+        else
+                fb->panel->bpp = 32;
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+        fb->panel->cntl |= CNTL_BEBO;
+#endif
+        fb->panel->width = -1;
+        fb->panel->height = -1;
+
+        if (of_property_read_u32_array(endpoint,
+                        "arm,pl11x,tft-r0g0b0-pads",
+                        tft_r0b0g0, ARRAY_SIZE(tft_r0b0g0)) == 0)
+                return clcdfb_of_init_tft_panel(fb, tft_r0b0g0[0],
+                                 tft_r0b0g0[1],  tft_r0b0g0[2]);
+
+        return -ENOENT;
+}
+
+static int clcdfb_of_vram_setup(struct clcd_fb *fb)
+{
+        int err;
+        struct device_node *memory;
+        u64 size;
+
+        err = clcdfb_of_init_display(fb);
+        if (err)
+                return err;
+
+        memory = of_parse_phandle(fb->dev->dev.of_node, "memory-region", 0);
+        if (!memory)
+                return -ENODEV;
+
+        fb->fb.screen_base = of_iomap(memory, 0);
+        if (!fb->fb.screen_base)
+                return -ENOMEM;
+
+        fb->fb.fix.smem_start = of_translate_address(memory,
+                        of_get_address(memory, 0, &size, NULL));
+        fb->fb.fix.smem_len = size;
+
+        return 0;
+}
+
+static int clcdfb_of_vram_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
+{
+        unsigned long off, user_size, kernel_size;
+
+
+        off = vma->vm_pgoff << PAGE_SHIFT;
+        user_size = vma->vm_end - vma->vm_start;
+        kernel_size = fb->fb.fix.smem_len;
+
+        if (off >= kernel_size || user_size > (kernel_size - off))
+                return -ENXIO;
+
+        return remap_pfn_range(vma, vma->vm_start,
+                        __phys_to_pfn(fb->fb.fix.smem_start) + vma->vm_pgoff,
+                        user_size,
+                        pgprot_writecombine(vma->vm_page_prot));
+}
+
+static void clcdfb_of_vram_remove(struct clcd_fb *fb)
+{
+        iounmap(fb->fb.screen_base);
+}
+
+static int clcdfb_of_dma_setup(struct clcd_fb *fb)
+{
+        unsigned long framesize;
+        dma_addr_t dma;
+        int err;
+
+        err = clcdfb_of_init_display(fb);
+        if (err)
+                return err;
+
+        framesize = fb->panel->mode.xres * fb->panel->mode.yres *
+                        fb->panel->bpp / 8;
+        fb->fb.screen_base = dma_alloc_coherent(&fb->dev->dev, framesize,
+                        &dma, GFP_KERNEL);
+        if (!fb->fb.screen_base)
+                return -ENOMEM;
+
+        fb->fb.fix.smem_start = dma;
+        fb->fb.fix.smem_len = framesize;
+
+        return 0;
+}
+
+static int clcdfb_of_dma_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
+{
+        return dma_mmap_writecombine(&fb->dev->dev, vma, fb->fb.screen_base,
+                        fb->fb.fix.smem_start, fb->fb.fix.smem_len);
+}
+
+static void clcdfb_of_dma_remove(struct clcd_fb *fb)
+{
+        dma_free_coherent(&fb->dev->dev, fb->fb.fix.smem_len,
+                        fb->fb.screen_base, fb->fb.fix.smem_start);
+}
+
+static struct clcd_board *clcdfb_of_get_board(struct amba_device *dev)
+{
+        struct clcd_board *board = devm_kzalloc(&dev->dev, sizeof(*board),
+                        GFP_KERNEL);
+        struct device_node *node = dev->dev.of_node;
+
+        if (!board)
+                return NULL;
+
+        board->name = of_node_full_name(node);
+        board->caps = CLCD_CAP_ALL;
+        board->check = clcdfb_check;
+        board->decode = clcdfb_decode;
+        if (of_find_property(node, "memory-region", NULL)) {
+                board->setup = clcdfb_of_vram_setup;
+                board->mmap = clcdfb_of_vram_mmap;
+                board->remove = clcdfb_of_vram_remove;
+        } else {
+                board->setup = clcdfb_of_dma_setup;
+                board->mmap = clcdfb_of_dma_mmap;
+                board->remove = clcdfb_of_dma_remove;
+        }
+
+        return board;
+}
+#else
+static struct clcd_board *clcdfb_of_get_board(struct amba_dev *dev)
+{
+        return NULL;
+}
+#endif
+
 static int clcdfb_probe(struct amba_device *dev, const struct amba_id *id)
 {
         struct clcd_board *board = dev_get_platdata(&dev->dev);
@@ -550,6 +810,9 @@ static int clcdfb_probe(struct amba_device *dev, const struct amba_id *id)
         int ret;
 
         if (!board)
+                board = clcdfb_of_get_board(dev);
+
+        if (!board)
                 return -EINVAL;
 
         ret = dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));