[PATCH 2/4] HID: picolcd: Add minimal palette required by fbcon on 8bpp

Bruno Prémont
2010-06-28T20:34:49Z

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>
---
drivers/hid/hid-picolcd.c | 62 +++++++++++++++++++++++++++++++++++++--------
1 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c
index 883d720..ac7aece 100644
--- 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;

--
1.7.1