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Release 4.7 drivers/hid/hid-picolcd_fb.c

Directory: drivers/hid
/***************************************************************************
 *   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; }

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/* 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; }

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void picolcd_fb_refresh(struct picolcd_data *data) { if (data->fb_info) schedule_delayed_work(&data->fb_info->deferred_work, 0); }

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/* 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; }

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/* 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); }

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/* 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); }

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/* 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); }

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/* 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); }

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/* * 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; }

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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; }

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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); }

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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; }

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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; }

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/* 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); }

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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; }

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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; }

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static DEVICE_ATTR(fb_update_rate, 0664, 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; }

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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); }

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Directory: drivers/hid
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