fbdev: hecuba Framebuffer Driver
authorJaya Kumar <jayakumar.lkml@gmail.com>
Tue, 8 May 2007 07:37:43 +0000 (00:37 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 8 May 2007 18:15:27 +0000 (11:15 -0700)
This patch implements support for the E-Ink/hecuba display device.  It uses
deferred IO support.

[akpm@linux-foundation.org: linker section fixes]
Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/video/Kconfig
drivers/video/Makefile
drivers/video/hecubafb.c [new file with mode: 0644]

index 61c0a03..0aeab4e 100644 (file)
@@ -557,6 +557,20 @@ config FB_IMAC
        help
          This is the frame buffer device driver for the Intel-based Macintosh
 
+config FB_HECUBA
+       tristate "Hecuba board support"
+       depends on FB && X86 && MMU
+       select FB_CFB_FILLRECT
+       select FB_CFB_COPYAREA
+       select FB_CFB_IMAGEBLIT
+       select FB_DEFERRED_IO
+       help
+         This enables support for the Hecuba board. This driver was tested
+         with an E-Ink 800x600 display and x86 SBCs through a 16 bit GPIO
+         interface (8 bit data, 4 bit control). If you anticpate using
+         this driver, say Y or M; otherwise say N. You must specify the
+         GPIO IO address to be used for setting control and data.
+
 config FB_HGA
        tristate "Hercules mono graphics support"
        depends on FB && X86
index deb5fa5..49d01eb 100644 (file)
@@ -67,6 +67,7 @@ obj-$(CONFIG_FB_ACORN)            += acornfb.o
 obj-$(CONFIG_FB_ATARI)            += atafb.o c2p.o atafb_mfb.o \
                                      atafb_iplan2p2.o atafb_iplan2p4.o atafb_iplan2p8.o
 obj-$(CONFIG_FB_MAC)              += macfb.o
+obj-$(CONFIG_FB_HECUBA)           += hecubafb.o
 obj-$(CONFIG_FB_HGA)              += hgafb.o
 obj-$(CONFIG_FB_XVR500)           += sunxvr500.o
 obj-$(CONFIG_FB_XVR2500)          += sunxvr2500.o
diff --git a/drivers/video/hecubafb.c b/drivers/video/hecubafb.c
new file mode 100644 (file)
index 0000000..396dc27
--- /dev/null
@@ -0,0 +1,480 @@
+/*
+ * linux/drivers/video/hecubafb.c -- FB driver for Hecuba controller
+ *
+ * Copyright (C) 2006, Jaya Kumar
+ * This work was sponsored by CIS(M) Sdn Bhd
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ *
+ * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
+ * This work was possible because of apollo display code from E-Ink's website
+ * http://support.eink.com/community
+ * All information used to write this code is from public material made
+ * available by E-Ink on its support site. Some commands such as 0xA4
+ * were found by looping through cmd=0x00 thru 0xFF and supplying random
+ * values. There are other commands that the display is capable of,
+ * beyond the 5 used here but they are more complex.
+ *
+ * This driver is written to be used with the Hecuba display controller
+ * board, and tested with the EInk 800x600 display in 1 bit mode.
+ * The interface between Hecuba and the host is TTL based GPIO. The
+ * GPIO requirements are 8 writable data lines and 6 lines for control.
+ * Only 4 of the controls are actually used here but 6 for future use.
+ * The driver requires the IO addresses for data and control GPIO at
+ * load time. It is also possible to use this display with a standard
+ * PC parallel port.
+ *
+ * General notes:
+ * - User must set hecubafb_enable=1 to enable it
+ * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR c2io_addr=0xIOADDR
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <asm/uaccess.h>
+
+/* Apollo controller specific defines */
+#define APOLLO_START_NEW_IMG   0xA0
+#define APOLLO_STOP_IMG_DATA   0xA1
+#define APOLLO_DISPLAY_IMG     0xA2
+#define APOLLO_ERASE_DISPLAY   0xA3
+#define APOLLO_INIT_DISPLAY    0xA4
+
+/* Hecuba interface specific defines */
+/* WUP is inverted, CD is inverted, DS is inverted */
+#define HCB_NWUP_BIT   0x01
+#define HCB_NDS_BIT    0x02
+#define HCB_RW_BIT     0x04
+#define HCB_NCD_BIT    0x08
+#define HCB_ACK_BIT    0x80
+
+/* Display specific information */
+#define DPY_W 600
+#define DPY_H 800
+
+struct hecubafb_par {
+       unsigned long dio_addr;
+       unsigned long cio_addr;
+       unsigned long c2io_addr;
+       unsigned char ctl;
+       struct fb_info *info;
+       unsigned int irq;
+};
+
+static struct fb_fix_screeninfo hecubafb_fix __devinitdata = {
+       .id =           "hecubafb",
+       .type =         FB_TYPE_PACKED_PIXELS,
+       .visual =       FB_VISUAL_MONO01,
+       .xpanstep =     0,
+       .ypanstep =     0,
+       .ywrapstep =    0,
+       .accel =        FB_ACCEL_NONE,
+};
+
+static struct fb_var_screeninfo hecubafb_var __devinitdata = {
+       .xres           = DPY_W,
+       .yres           = DPY_H,
+       .xres_virtual   = DPY_W,
+       .yres_virtual   = DPY_H,
+       .bits_per_pixel = 1,
+       .nonstd         = 1,
+};
+
+static unsigned long dio_addr;
+static unsigned long cio_addr;
+static unsigned long c2io_addr;
+static unsigned long splashval;
+static unsigned int nosplash;
+static unsigned int hecubafb_enable;
+static unsigned int irq;
+
+static DECLARE_WAIT_QUEUE_HEAD(hecubafb_waitq);
+
+static void hcb_set_ctl(struct hecubafb_par *par)
+{
+       outb(par->ctl, par->cio_addr);
+}
+
+static unsigned char hcb_get_ctl(struct hecubafb_par *par)
+{
+       return inb(par->c2io_addr);
+}
+
+static void hcb_set_data(struct hecubafb_par *par, unsigned char value)
+{
+       outb(value, par->dio_addr);
+}
+
+static int __devinit apollo_init_control(struct hecubafb_par *par)
+{
+       unsigned char ctl;
+       /* for init, we want the following setup to be set:
+       WUP = lo
+       ACK = hi
+       DS = hi
+       RW = hi
+       CD = lo
+       */
+
+       /* write WUP to lo, DS to hi, RW to hi, CD to lo */
+       par->ctl = HCB_NWUP_BIT | HCB_RW_BIT | HCB_NCD_BIT ;
+       par->ctl &= ~HCB_NDS_BIT;
+       hcb_set_ctl(par);
+
+       /* check ACK is not lo */
+       ctl = hcb_get_ctl(par);
+       if ((ctl & HCB_ACK_BIT)) {
+               printk(KERN_ERR "Fail because ACK is already low\n");
+               return -ENXIO;
+       }
+
+       return 0;
+}
+
+void hcb_wait_for_ack(struct hecubafb_par *par)
+{
+
+       int timeout;
+       unsigned char ctl;
+
+       timeout=500;
+       do {
+               ctl = hcb_get_ctl(par);
+               if ((ctl & HCB_ACK_BIT))
+                       return;
+               udelay(1);
+       } while (timeout--);
+       printk(KERN_ERR "timed out waiting for ack\n");
+}
+
+void hcb_wait_for_ack_clear(struct hecubafb_par *par)
+{
+
+       int timeout;
+       unsigned char ctl;
+
+       timeout=500;
+       do {
+               ctl = hcb_get_ctl(par);
+               if (!(ctl & HCB_ACK_BIT))
+                       return;
+               udelay(1);
+       } while (timeout--);
+       printk(KERN_ERR "timed out waiting for clear\n");
+}
+
+void apollo_send_data(struct hecubafb_par *par, unsigned char data)
+{
+       /* set data */
+       hcb_set_data(par, data);
+
+       /* set DS low */
+       par->ctl |= HCB_NDS_BIT;
+       hcb_set_ctl(par);
+
+       hcb_wait_for_ack(par);
+
+       /* set DS hi */
+       par->ctl &= ~(HCB_NDS_BIT);
+       hcb_set_ctl(par);
+
+       hcb_wait_for_ack_clear(par);
+}
+
+void apollo_send_command(struct hecubafb_par *par, unsigned char data)
+{
+       /* command so set CD to high */
+       par->ctl &= ~(HCB_NCD_BIT);
+       hcb_set_ctl(par);
+
+       /* actually strobe with command */
+       apollo_send_data(par, data);
+
+       /* clear CD back to low */
+       par->ctl |= (HCB_NCD_BIT);
+       hcb_set_ctl(par);
+}
+
+/* main hecubafb functions */
+
+static void hecubafb_dpy_update(struct hecubafb_par *par)
+{
+       int i;
+       unsigned char *buf = par->info->screen_base;
+
+       apollo_send_command(par, 0xA0);
+
+       for (i=0; i < (DPY_W*DPY_H/8); i++) {
+               apollo_send_data(par, *(buf++));
+       }
+
+       apollo_send_command(par, 0xA1);
+       apollo_send_command(par, 0xA2);
+}
+
+/* this is called back from the deferred io workqueue */
+static void hecubafb_dpy_deferred_io(struct fb_info *info,
+                               struct list_head *pagelist)
+{
+       hecubafb_dpy_update(info->par);
+}
+
+static void hecubafb_fillrect(struct fb_info *info,
+                                  const struct fb_fillrect *rect)
+{
+       struct hecubafb_par *par = info->par;
+
+       cfb_fillrect(info, rect);
+
+       hecubafb_dpy_update(par);
+}
+
+static void hecubafb_copyarea(struct fb_info *info,
+                                  const struct fb_copyarea *area)
+{
+       struct hecubafb_par *par = info->par;
+
+       cfb_copyarea(info, area);
+
+       hecubafb_dpy_update(par);
+}
+
+static void hecubafb_imageblit(struct fb_info *info,
+                               const struct fb_image *image)
+{
+       struct hecubafb_par *par = info->par;
+
+       cfb_imageblit(info, image);
+
+       hecubafb_dpy_update(par);
+}
+
+/*
+ * 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 hecubafb_write(struct file *file, const char __user *buf,
+                               size_t count, loff_t *ppos)
+{
+       struct inode *inode;
+       int fbidx;
+       struct fb_info *info;
+       unsigned long p;
+       int err=-EINVAL;
+       struct hecubafb_par *par;
+       unsigned int xres;
+       unsigned int fbmemlength;
+
+       p = *ppos;
+       inode = file->f_dentry->d_inode;
+       fbidx = iminor(inode);
+       info = registered_fb[fbidx];
+
+       if (!info || !info->screen_base)
+               return -ENODEV;
+
+       par = info->par;
+       xres = info->var.xres;
+       fbmemlength = (xres * info->var.yres)/8;
+
+       if (p > fbmemlength)
+               return -ENOSPC;
+
+       err = 0;
+       if ((count + p) > fbmemlength) {
+               count = fbmemlength - p;
+               err = -ENOSPC;
+       }
+
+       if (count) {
+               char *base_addr;
+
+               base_addr = info->screen_base;
+               count -= copy_from_user(base_addr + p, buf, count);
+               *ppos += count;
+               err = -EFAULT;
+       }
+
+       hecubafb_dpy_update(par);
+
+       if (count)
+               return count;
+
+       return err;
+}
+
+static struct fb_ops hecubafb_ops = {
+       .owner          = THIS_MODULE,
+       .fb_write       = hecubafb_write,
+       .fb_fillrect    = hecubafb_fillrect,
+       .fb_copyarea    = hecubafb_copyarea,
+       .fb_imageblit   = hecubafb_imageblit,
+};
+
+static struct fb_deferred_io hecubafb_defio = {
+       .delay          = HZ,
+       .deferred_io    = hecubafb_dpy_deferred_io,
+};
+
+static int __devinit hecubafb_probe(struct platform_device *dev)
+{
+       struct fb_info *info;
+       int retval = -ENOMEM;
+       int videomemorysize;
+       unsigned char *videomemory;
+       struct hecubafb_par *par;
+
+       videomemorysize = (DPY_W*DPY_H)/8;
+
+       if (!(videomemory = vmalloc(videomemorysize)))
+               return retval;
+
+       memset(videomemory, 0, videomemorysize);
+
+       info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
+       if (!info)
+               goto err;
+
+       info->screen_base = (char __iomem *) videomemory;
+       info->fbops = &hecubafb_ops;
+
+       info->var = hecubafb_var;
+       info->fix = hecubafb_fix;
+       info->fix.smem_len = videomemorysize;
+       par = info->par;
+       par->info = info;
+
+       if (!dio_addr || !cio_addr || !c2io_addr) {
+               printk(KERN_WARNING "no IO addresses supplied\n");
+               goto err1;
+       }
+       par->dio_addr = dio_addr;
+       par->cio_addr = cio_addr;
+       par->c2io_addr = c2io_addr;
+       info->flags = FBINFO_FLAG_DEFAULT;
+
+       info->fbdefio = &hecubafb_defio;
+       fb_deferred_io_init(info);
+
+       retval = register_framebuffer(info);
+       if (retval < 0)
+               goto err1;
+       platform_set_drvdata(dev, info);
+
+       printk(KERN_INFO
+              "fb%d: Hecuba frame buffer device, using %dK of video memory\n",
+              info->node, videomemorysize >> 10);
+
+       /* this inits the dpy */
+       apollo_init_control(par);
+
+       apollo_send_command(par, APOLLO_INIT_DISPLAY);
+       apollo_send_data(par, 0x81);
+
+       /* have to wait while display resets */
+       udelay(1000);
+
+       /* if we were told to splash the screen, we just clear it */
+       if (!nosplash) {
+               apollo_send_command(par, APOLLO_ERASE_DISPLAY);
+               apollo_send_data(par, splashval);
+       }
+
+       return 0;
+err1:
+       framebuffer_release(info);
+err:
+       vfree(videomemory);
+       return retval;
+}
+
+static int __devexit hecubafb_remove(struct platform_device *dev)
+{
+       struct fb_info *info = platform_get_drvdata(dev);
+
+       if (info) {
+               fb_deferred_io_cleanup(info);
+               unregister_framebuffer(info);
+               vfree(info->screen_base);
+               framebuffer_release(info);
+       }
+       return 0;
+}
+
+static struct platform_driver hecubafb_driver = {
+       .probe  = hecubafb_probe,
+       .remove = hecubafb_remove,
+       .driver = {
+               .name   = "hecubafb",
+       },
+};
+
+static struct platform_device *hecubafb_device;
+
+static int __init hecubafb_init(void)
+{
+       int ret;
+
+       if (!hecubafb_enable) {
+               printk(KERN_ERR "Use hecubafb_enable to enable the device\n");
+               return -ENXIO;
+       }
+
+       ret = platform_driver_register(&hecubafb_driver);
+       if (!ret) {
+               hecubafb_device = platform_device_alloc("hecubafb", 0);
+               if (hecubafb_device)
+                       ret = platform_device_add(hecubafb_device);
+               else
+                       ret = -ENOMEM;
+
+               if (ret) {
+                       platform_device_put(hecubafb_device);
+                       platform_driver_unregister(&hecubafb_driver);
+               }
+       }
+       return ret;
+
+}
+
+static void __exit hecubafb_exit(void)
+{
+       platform_device_unregister(hecubafb_device);
+       platform_driver_unregister(&hecubafb_driver);
+}
+
+module_param(nosplash, uint, 0);
+MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
+module_param(hecubafb_enable, uint, 0);
+MODULE_PARM_DESC(hecubafb_enable, "Enable communication with Hecuba board");
+module_param(dio_addr, ulong, 0);
+MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
+module_param(cio_addr, ulong, 0);
+MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
+module_param(c2io_addr, ulong, 0);
+MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
+module_param(splashval, ulong, 0);
+MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");
+module_param(irq, uint, 0);
+MODULE_PARM_DESC(irq, "IRQ for the Hecuba board");
+
+module_init(hecubafb_init);
+module_exit(hecubafb_exit);
+
+MODULE_DESCRIPTION("fbdev driver for Hecuba board");
+MODULE_AUTHOR("Jaya Kumar");
+MODULE_LICENSE("GPL");