HID: picolcd: Add minimal palette required by fbcon on 8bpp

Add a minimal palette so fbcon does not try to dereference
a NULL point when fb is set to 8bpp.

fbcon stores pixels the other way around in bytes for 1bpp
than intially implemented, correct this.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c
index 839a5ac..dc19501 100644 (file)
--- a/drivers/hid/hid-picolcd.c
+++ b/drivers/hid/hid-picolcd.c
@@ -127,6 +127,26 @@ static const struct fb_var_screeninfo picolcdfb_var = {
        .height         = 26,
        .bits_per_pixel = 1,
        .grayscale      = 1,
+       .red            = {
+               .offset = 0,
+               .length = 1,
+               .msb_right = 0,
+       },
+       .green          = {
+               .offset = 0,
+               .length = 1,
+               .msb_right = 0,
+       },
+       .blue           = {
+               .offset = 0,
+               .length = 1,
+               .msb_right = 0,
+       },
+       .transp         = {
+               .offset = 0,
+               .length = 0,
+               .msb_right = 0,
+       },
 };
 #endif /* CONFIG_HID_PICOLCD_FB */
 
@@ -188,6 +208,7 @@ struct picolcd_data {
        /* Framebuffer stuff */
        u8 fb_update_rate;
        u8 fb_bpp;
+       u8 fb_force;
        u8 *fb_vbitmap;         /* local copy of what was sent to PicoLCD */
        u8 *fb_bitmap;          /* framebuffer */
        struct fb_info *fb_info;
@@ -346,7 +367,7 @@ static int picolcd_fb_update_tile(u8 *vbitmap, const u8 *bitmap, int bpp,
                        const u8 *bdata = bitmap + tile * 256 + chip * 8 + b * 32;
                        for (i = 0; i < 64; i++) {
                                tdata[i] <<= 1;
-                               tdata[i] |= (bdata[i/8] >> (7 - i % 8)) & 0x01;
+                               tdata[i] |= (bdata[i/8] >> (i % 8)) & 0x01;
                        }
                }
        } else if (bpp == 8) {
@@ -399,13 +420,10 @@ static int picolcd_fb_reset(struct picolcd_data *data, int clear)
 
        if (data->fb_bitmap) {
                if (clear) {
-                       memset(data->fb_vbitmap, 0xff, PICOLCDFB_SIZE);
+                       memset(data->fb_vbitmap, 0, PICOLCDFB_SIZE);
                        memset(data->fb_bitmap, 0, PICOLCDFB_SIZE*data->fb_bpp);
-               } else {
-                       /* invert 1 byte in each tile to force resend */
-                       for (i = 0; i < PICOLCDFB_SIZE; i += 64)
-                               data->fb_vbitmap[i] = ~data->fb_vbitmap[i];
                }
+               data->fb_force = 1;
        }
 
        /* schedule first output of framebuffer */
@@ -440,7 +458,8 @@ static void picolcd_fb_update(struct picolcd_data *data)
        for (chip = 0; chip < 4; chip++)
                for (tile = 0; tile < 8; tile++)
                        if (picolcd_fb_update_tile(data->fb_vbitmap,
-                                       data->fb_bitmap, data->fb_bpp, chip, tile)) {
+                                       data->fb_bitmap, data->fb_bpp, chip, tile) ||
+                               data->fb_force) {
                                n += 2;
                                if (n >= HID_OUTPUT_FIFO_SIZE / 2) {
                                        usbhid_wait_io(data->hdev);
@@ -448,6 +467,7 @@ static void picolcd_fb_update(struct picolcd_data *data)
                                }
                                picolcd_fb_send_tile(data->hdev, chip, tile);
                        }
+       data->fb_force = false;
        if (n)
                usbhid_wait_io(data->hdev);
 }
@@ -526,10 +546,17 @@ static int picolcd_fb_check_var(struct fb_var_screeninfo *var, struct fb_info *i
        /* only allow 1/8 bit depth (8-bit is grayscale) */
        *var = picolcdfb_var;
        var->activate = activate;
-       if (bpp >= 8)
+       if (bpp >= 8) {
                var->bits_per_pixel = 8;
-       else
+               var->red.length     = 8;
+               var->green.length   = 8;
+               var->blue.length    = 8;
+       } else {
                var->bits_per_pixel = 1;
+               var->red.length     = 1;
+               var->green.length   = 1;
+               var->blue.length    = 1;
+       }
        return 0;
 }
 
@@ -660,9 +687,10 @@ static int picolcd_init_framebuffer(struct picolcd_data *data)
 {
        struct device *dev = &data->hdev->dev;
        struct fb_info *info = NULL;
-       int error = -ENOMEM;
+       int i, error = -ENOMEM;
        u8 *fb_vbitmap = NULL;
        u8 *fb_bitmap  = NULL;
+       u32 *palette;
 
        fb_bitmap = vmalloc(PICOLCDFB_SIZE*picolcdfb_var.bits_per_pixel);
        if (fb_bitmap == NULL) {
@@ -678,12 +706,23 @@ static int picolcd_init_framebuffer(struct picolcd_data *data)
 
        data->fb_update_rate = PICOLCDFB_UPDATE_RATE_DEFAULT;
        data->fb_defio = picolcd_fb_defio;
-       info = framebuffer_alloc(0, dev);
+       /* The extra memory is:
+        * - struct picolcd_fb_cleanup_item
+        * - u32 for ref_count
+        * - 256*u32 for pseudo_palette
+        */
+       info = framebuffer_alloc(257 * sizeof(u32), dev);
        if (info == NULL) {
                dev_err(dev, "failed to allocate a framebuffer\n");
                goto err_nomem;
        }
 
+       palette  = info->par;
+       *palette = 1;
+       palette++;
+       for (i = 0; i < 256; i++)
+               palette[i] = i > 0 && i < 16 ? 0xff : 0;
+       info->pseudo_palette = palette;
        info->fbdefio = &data->fb_defio;
        info->screen_base = (char __force __iomem *)fb_bitmap;
        info->fbops = &picolcdfb_ops;
@@ -715,6 +754,7 @@ static int picolcd_init_framebuffer(struct picolcd_data *data)
                goto err_sysfs;
        }
        /* schedule first output of framebuffer */
+       data->fb_force = 1;
        schedule_delayed_work(&info->deferred_work, 0);
        return 0;