/***************************************************************************
* Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> *
* *
* Based on Logitech G13 driver (v0.4) *
* Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> *
* *
* This program is free software: you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation, version 2 of the License. *
* *
* This driver is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this software. If not see <http://www.gnu.org/licenses/>. *
***************************************************************************/
#include <linux/hid.h>
#include <linux/vmalloc.h>
#include <linux/fb.h>
#include <linux/module.h>
#include "hid-picolcd.h"
/* Framebuffer
*
* The PicoLCD use a Topway LCD module of 256x64 pixel
* This display area is tiled over 4 controllers with 8 tiles
* each. Each tile has 8x64 pixel, each data byte representing
* a 1-bit wide vertical line of the tile.
*
* The display can be updated at a tile granularity.
*
* Chip 1 Chip 2 Chip 3 Chip 4
* +----------------+----------------+----------------+----------------+
* | Tile 1 | Tile 1 | Tile 1 | Tile 1 |
* +----------------+----------------+----------------+----------------+
* | Tile 2 | Tile 2 | Tile 2 | Tile 2 |
* +----------------+----------------+----------------+----------------+
* ...
* +----------------+----------------+----------------+----------------+
* | Tile 8 | Tile 8 | Tile 8 | Tile 8 |
* +----------------+----------------+----------------+----------------+
*/
#define PICOLCDFB_NAME "picolcdfb"
#define PICOLCDFB_WIDTH (256)
#define PICOLCDFB_HEIGHT (64)
#define PICOLCDFB_SIZE (PICOLCDFB_WIDTH * PICOLCDFB_HEIGHT / 8)
#define PICOLCDFB_UPDATE_RATE_LIMIT 10
#define PICOLCDFB_UPDATE_RATE_DEFAULT 2
/* Framebuffer visual structures */
static const struct fb_fix_screeninfo picolcdfb_fix = {
.id = PICOLCDFB_NAME,
.type = FB_TYPE_PACKED_PIXELS,
.visual = FB_VISUAL_MONO01,
.xpanstep = 0,
.ypanstep = 0,
.ywrapstep = 0,
.line_length = PICOLCDFB_WIDTH / 8,
.accel = FB_ACCEL_NONE,
};
static const struct fb_var_screeninfo picolcdfb_var = {
.xres = PICOLCDFB_WIDTH,
.yres = PICOLCDFB_HEIGHT,
.xres_virtual = PICOLCDFB_WIDTH,
.yres_virtual = PICOLCDFB_HEIGHT,
.width = 103,
.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,
},
};
/* Send a given tile to PicoLCD */
static int picolcd_fb_send_tile(struct picolcd_data *data, u8 *vbitmap,
int chip, int tile)
{
struct hid_report *report1, *report2;
unsigned long flags;
u8 *tdata;
int i;
report1 = picolcd_out_report(REPORT_LCD_CMD_DATA, data->hdev);
if (!report1 || report1->maxfield != 1)
return -ENODEV;
report2 = picolcd_out_report(REPORT_LCD_DATA, data->hdev);
if (!report2 || report2->maxfield != 1)
return -ENODEV;
spin_lock_irqsave(&data->lock, flags);
if ((data->status & PICOLCD_FAILED)) {
spin_unlock_irqrestore(&data->lock, flags);
return -ENODEV;
}
hid_set_field(report1->field[0], 0, chip << 2);
hid_set_field(report1->field[0], 1, 0x02);
hid_set_field(report1->field[0], 2, 0x00);
hid_set_field(report1->field[0], 3, 0x00);
hid_set_field(report1->field[0], 4, 0xb8 | tile);
hid_set_field(report1->field[0], 5, 0x00);
hid_set_field(report1->field[0], 6, 0x00);
hid_set_field(report1->field[0], 7, 0x40);
hid_set_field(report1->field[0], 8, 0x00);
hid_set_field(report1->field[0], 9, 0x00);
hid_set_field(report1->field[0], 10, 32);
hid_set_field(report2->field[0], 0, (chip << 2) | 0x01);
hid_set_field(report2->field[0], 1, 0x00);
hid_set_field(report2->field[0], 2, 0x00);
hid_set_field(report2->field[0], 3, 32);
tdata = vbitmap + (tile * 4 + chip) * 64;
for (i = 0; i < 64; i++)
if (i < 32)
hid_set_field(report1->field[0], 11 + i, tdata[i]);
else
hid_set_field(report2->field[0], 4 + i - 32, tdata[i]);
hid_hw_request(data->hdev, report1, HID_REQ_SET_REPORT);
hid_hw_request(data->hdev, report2, HID_REQ_SET_REPORT);
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
/* Translate a single tile*/
static int picolcd_fb_update_tile(u8 *vbitmap, const u8 *bitmap, int bpp,
int chip, int tile)
{
int i, b, changed = 0;
u8 tdata[64];
u8 *vdata = vbitmap + (tile * 4 + chip) * 64;
if (bpp == 1) {
for (b = 7; b >= 0; b--) {
const u8 *bdata = bitmap + tile * 256 + chip * 8 + b * 32;
for (i = 0; i < 64; i++) {
tdata[i] <<= 1;
tdata[i] |= (bdata[i/8] >> (i % 8)) & 0x01;
}
}
} else if (bpp == 8) {
for (b = 7; b >= 0; b--) {
const u8 *bdata = bitmap + (tile * 256 + chip * 8 + b * 32) * 8;
for (i = 0; i < 64; i++) {
tdata[i] <<= 1;
tdata[i] |= (bdata[i] & 0x80) ? 0x01 : 0x00;
}
}
} else {
/* Oops, we should never get here! */
WARN_ON(1);
return 0;
}
for (i = 0; i < 64; i++)
if (tdata[i] != vdata[i]) {
changed = 1;
vdata[i] = tdata[i];
}
return changed;
}
void picolcd_fb_refresh(struct picolcd_data *data)
{
if (data->fb_info)
schedule_delayed_work(&data->fb_info->deferred_work, 0);
}
/* Reconfigure LCD display */
int picolcd_fb_reset(struct picolcd_data *data, int clear)
{
struct hid_report *report = picolcd_out_report(REPORT_LCD_CMD, data->hdev);
struct picolcd_fb_data *fbdata = data->fb_info->par;
int i, j;
unsigned long flags;
static const u8 mapcmd[8] = { 0x00, 0x02, 0x00, 0x64, 0x3f, 0x00, 0x64, 0xc0 };
if (!report || report->maxfield != 1)
return -ENODEV;
spin_lock_irqsave(&data->lock, flags);
for (i = 0; i < 4; i++) {
for (j = 0; j < report->field[0]->maxusage; j++)
if (j == 0)
hid_set_field(report->field[0], j, i << 2);
else if (j < sizeof(mapcmd))
hid_set_field(report->field[0], j, mapcmd[j]);
else
hid_set_field(report->field[0], j, 0);
hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
}
spin_unlock_irqrestore(&data->lock, flags);
if (clear) {
memset(fbdata->vbitmap, 0, PICOLCDFB_SIZE);
memset(fbdata->bitmap, 0, PICOLCDFB_SIZE*fbdata->bpp);
}
fbdata->force = 1;
/* schedule first output of framebuffer */
if (fbdata->ready)
schedule_delayed_work(&data->fb_info->deferred_work, 0);
else
fbdata->ready = 1;
return 0;
}
/* Update fb_vbitmap from the screen_base and send changed tiles to device */
static void picolcd_fb_update(struct fb_info *info)
{
int chip, tile, n;
unsigned long flags;
struct picolcd_fb_data *fbdata = info->par;
struct picolcd_data *data;
mutex_lock(&info->lock);
spin_lock_irqsave(&fbdata->lock, flags);
if (!fbdata->ready && fbdata->picolcd)
picolcd_fb_reset(fbdata->picolcd, 0);
spin_unlock_irqrestore(&fbdata->lock, flags);
/*
* Translate the framebuffer into the format needed by the PicoLCD.
* See display layout above.
* Do this one tile after the other and push those tiles that changed.
*
* Wait for our IO to complete as otherwise we might flood the queue!
*/
n = 0;
for (chip = 0; chip < 4; chip++)
for (tile = 0; tile < 8; tile++) {
if (!fbdata->force && !picolcd_fb_update_tile(
fbdata->vbitmap, fbdata->bitmap,
fbdata->bpp, chip, tile))
continue;
n += 2;
if (n >= HID_OUTPUT_FIFO_SIZE / 2) {
spin_lock_irqsave(&fbdata->lock, flags);
data = fbdata->picolcd;
spin_unlock_irqrestore(&fbdata->lock, flags);
mutex_unlock(&info->lock);
if (!data)
return;
hid_hw_wait(data->hdev);
mutex_lock(&info->lock);
n = 0;
}
spin_lock_irqsave(&fbdata->lock, flags);
data = fbdata->picolcd;
spin_unlock_irqrestore(&fbdata->lock, flags);
if (!data || picolcd_fb_send_tile(data,
fbdata->vbitmap, chip, tile))
goto out;
}
fbdata->force = false;
if (n) {
spin_lock_irqsave(&fbdata->lock, flags);
data = fbdata->picolcd;
spin_unlock_irqrestore(&fbdata->lock, flags);
mutex_unlock(&info->lock);
if (data)
hid_hw_wait(data->hdev);
return;
}
out:
mutex_unlock(&info->lock);
}
/* Stub to call the system default and update the image on the picoLCD */
static void picolcd_fb_fillrect(struct fb_info *info,
const struct fb_fillrect *rect)
{
if (!info->par)
return;
sys_fillrect(info, rect);
schedule_delayed_work(&info->deferred_work, 0);
}
/* Stub to call the system default and update the image on the picoLCD */
static void picolcd_fb_copyarea(struct fb_info *info,
const struct fb_copyarea *area)
{
if (!info->par)
return;
sys_copyarea(info, area);
schedule_delayed_work(&info->deferred_work, 0);
}
/* Stub to call the system default and update the image on the picoLCD */
static void picolcd_fb_imageblit(struct fb_info *info, const struct fb_image *image)
{
if (!info->par)
return;
sys_imageblit(info, image);
schedule_delayed_work(&info->deferred_work, 0);
}
/*
* this is the slow path from userspace. they can seek and write to
* the fb. it's inefficient to do anything less than a full screen draw
*/
static ssize_t picolcd_fb_write(struct fb_info *info, const char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t ret;
if (!info->par)
return -ENODEV;
ret = fb_sys_write(info, buf, count, ppos);
if (ret >= 0)
schedule_delayed_work(&info->deferred_work, 0);
return ret;
}
static int picolcd_fb_blank(int blank, struct fb_info *info)
{
/* We let fb notification do this for us via lcd/backlight device */
return 0;
}
static void picolcd_fb_destroy(struct fb_info *info)
{
struct picolcd_fb_data *fbdata = info->par;
/* make sure no work is deferred */
fb_deferred_io_cleanup(info);
/* No thridparty should ever unregister our framebuffer! */
WARN_ON(fbdata->picolcd != NULL);
vfree((u8 *)info->fix.smem_start);
framebuffer_release(info);
}
static int picolcd_fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
__u32 bpp = var->bits_per_pixel;
__u32 activate = var->activate;
/* only allow 1/8 bit depth (8-bit is grayscale) */
*var = picolcdfb_var;
var->activate = activate;
if (bpp >= 8) {
var->bits_per_pixel = 8;
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;
}
static int picolcd_set_par(struct fb_info *info)
{
struct picolcd_fb_data *fbdata = info->par;
u8 *tmp_fb, *o_fb;
if (info->var.bits_per_pixel == fbdata->bpp)
return 0;
/* switch between 1/8 bit depths */
if (info->var.bits_per_pixel != 1 && info->var.bits_per_pixel != 8)
return -EINVAL;
o_fb = fbdata->bitmap;
tmp_fb = kmalloc(PICOLCDFB_SIZE*info->var.bits_per_pixel, GFP_KERNEL);
if (!tmp_fb)
return -ENOMEM;
/* translate FB content to new bits-per-pixel */
if (info->var.bits_per_pixel == 1) {
int i, b;
for (i = 0; i < PICOLCDFB_SIZE; i++) {
u8 p = 0;
for (b = 0; b < 8; b++) {
p <<= 1;
p |= o_fb[i*8+b] ? 0x01 : 0x00;
}
tmp_fb[i] = p;
}
memcpy(o_fb, tmp_fb, PICOLCDFB_SIZE);
info->fix.visual = FB_VISUAL_MONO01;
info->fix.line_length = PICOLCDFB_WIDTH / 8;
} else {
int i;
memcpy(tmp_fb, o_fb, PICOLCDFB_SIZE);
for (i = 0; i < PICOLCDFB_SIZE * 8; i++)
o_fb[i] = tmp_fb[i/8] & (0x01 << (7 - i % 8)) ? 0xff : 0x00;
info->fix.visual = FB_VISUAL_DIRECTCOLOR;
info->fix.line_length = PICOLCDFB_WIDTH;
}
kfree(tmp_fb);
fbdata->bpp = info->var.bits_per_pixel;
return 0;
}
/* Note this can't be const because of struct fb_info definition */
static struct fb_ops picolcdfb_ops = {
.owner = THIS_MODULE,
.fb_destroy = picolcd_fb_destroy,
.fb_read = fb_sys_read,
.fb_write = picolcd_fb_write,
.fb_blank = picolcd_fb_blank,
.fb_fillrect = picolcd_fb_fillrect,
.fb_copyarea = picolcd_fb_copyarea,
.fb_imageblit = picolcd_fb_imageblit,
.fb_check_var = picolcd_fb_check_var,
.fb_set_par = picolcd_set_par,
};
/* Callback from deferred IO workqueue */
static void picolcd_fb_deferred_io(struct fb_info *info, struct list_head *pagelist)
{
picolcd_fb_update(info);
}
static const struct fb_deferred_io picolcd_fb_defio = {
.delay = HZ / PICOLCDFB_UPDATE_RATE_DEFAULT,
.deferred_io = picolcd_fb_deferred_io,
};
/*
* The "fb_update_rate" sysfs attribute
*/
static ssize_t picolcd_fb_update_rate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct picolcd_data *data = dev_get_drvdata(dev);
struct picolcd_fb_data *fbdata = data->fb_info->par;
unsigned i, fb_update_rate = fbdata->update_rate;
size_t ret = 0;
for (i = 1; i <= PICOLCDFB_UPDATE_RATE_LIMIT; i++)
if (ret >= PAGE_SIZE)
break;
else if (i == fb_update_rate)
ret += snprintf(buf+ret, PAGE_SIZE-ret, "[%u] ", i);
else
ret += snprintf(buf+ret, PAGE_SIZE-ret, "%u ", i);
if (ret > 0)
buf[min(ret, (size_t)PAGE_SIZE)-1] = '\n';
return ret;
}
static ssize_t picolcd_fb_update_rate_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct picolcd_data *data = dev_get_drvdata(dev);
struct picolcd_fb_data *fbdata = data->fb_info->par;
int i;
unsigned u;
if (count < 1 || count > 10)
return -EINVAL;
i = sscanf(buf, "%u", &u);
if (i != 1)
return -EINVAL;
if (u > PICOLCDFB_UPDATE_RATE_LIMIT)
return -ERANGE;
else if (u == 0)
u = PICOLCDFB_UPDATE_RATE_DEFAULT;
fbdata->update_rate = u;
data->fb_info->fbdefio->delay = HZ / fbdata->update_rate;
return count;
}
static DEVICE_ATTR(fb_update_rate, 0666, picolcd_fb_update_rate_show,
picolcd_fb_update_rate_store);
/* initialize Framebuffer device */
int picolcd_init_framebuffer(struct picolcd_data *data)
{
struct device *dev = &data->hdev->dev;
struct fb_info *info = NULL;
struct picolcd_fb_data *fbdata = NULL;
int i, error = -ENOMEM;
u32 *palette;
/* The extra memory is:
* - 256*u32 for pseudo_palette
* - struct fb_deferred_io
*/
info = framebuffer_alloc(256 * sizeof(u32) +
sizeof(struct fb_deferred_io) +
sizeof(struct picolcd_fb_data) +
PICOLCDFB_SIZE, dev);
if (info == NULL) {
dev_err(dev, "failed to allocate a framebuffer\n");
goto err_nomem;
}
info->fbdefio = info->par;
*info->fbdefio = picolcd_fb_defio;
info->par += sizeof(struct fb_deferred_io);
palette = info->par;
info->par += 256 * sizeof(u32);
for (i = 0; i < 256; i++)
palette[i] = i > 0 && i < 16 ? 0xff : 0;
info->pseudo_palette = palette;
info->fbops = &picolcdfb_ops;
info->var = picolcdfb_var;
info->fix = picolcdfb_fix;
info->fix.smem_len = PICOLCDFB_SIZE*8;
info->flags = FBINFO_FLAG_DEFAULT;
fbdata = info->par;
spin_lock_init(&fbdata->lock);
fbdata->picolcd = data;
fbdata->update_rate = PICOLCDFB_UPDATE_RATE_DEFAULT;
fbdata->bpp = picolcdfb_var.bits_per_pixel;
fbdata->force = 1;
fbdata->vbitmap = info->par + sizeof(struct picolcd_fb_data);
fbdata->bitmap = vmalloc(PICOLCDFB_SIZE*8);
if (fbdata->bitmap == NULL) {
dev_err(dev, "can't get a free page for framebuffer\n");
goto err_nomem;
}
info->screen_base = (char __force __iomem *)fbdata->bitmap;
info->fix.smem_start = (unsigned long)fbdata->bitmap;
memset(fbdata->vbitmap, 0xff, PICOLCDFB_SIZE);
data->fb_info = info;
error = picolcd_fb_reset(data, 1);
if (error) {
dev_err(dev, "failed to configure display\n");
goto err_cleanup;
}
error = device_create_file(dev, &dev_attr_fb_update_rate);
if (error) {
dev_err(dev, "failed to create sysfs attributes\n");
goto err_cleanup;
}
fb_deferred_io_init(info);
error = register_framebuffer(info);
if (error) {
dev_err(dev, "failed to register framebuffer\n");
goto err_sysfs;
}
return 0;
err_sysfs:
device_remove_file(dev, &dev_attr_fb_update_rate);
fb_deferred_io_cleanup(info);
err_cleanup:
data->fb_info = NULL;
err_nomem:
if (fbdata)
vfree(fbdata->bitmap);
framebuffer_release(info);
return error;
}
void picolcd_exit_framebuffer(struct picolcd_data *data)
{
struct fb_info *info = data->fb_info;
struct picolcd_fb_data *fbdata;
unsigned long flags;
if (!info)
return;
device_remove_file(&data->hdev->dev, &dev_attr_fb_update_rate);
fbdata = info->par;
/* disconnect framebuffer from HID dev */
spin_lock_irqsave(&fbdata->lock, flags);
fbdata->picolcd = NULL;
spin_unlock_irqrestore(&fbdata->lock, flags);
/* make sure there is no running update - thus that fbdata->picolcd
* once obtained under lock is guaranteed not to get free() under
* the feet of the deferred work */
flush_delayed_work(&info->deferred_work);
data->fb_info = NULL;
unregister_framebuffer(info);
}
