[PATCH] Framebuffer driver for Arc LCD board

Add support for the Arc monochrome LCD board.

The board uses KS108 controllers to drive individual 64x64 LCD matrices.
The board can be paneled in a variety of setups such as 2x1=128x64,
4x4=256x256 and so on.  The board/host interface is through GPIO.

Signed-off-by: Jaya Kumar <jayalk@intworks.biz>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: <linux-fbdev-devel@lists.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 684 insertions, 0 deletions

diff --git a/drivers/video/arcfb.c b/drivers/video/arcfb.c
new file mode 100644
index 000000000000..d28457e0c063
--- /dev/null
+++ b/drivers/video/arcfb.c
@@ -0,0 +1,684 @@
+/*
+ * linux/drivers/video/arcfb.c -- FB driver for Arc monochrome LCD board
+ *
+ * Copyright (C) 2005, Jaya Kumar <jayalk@intworks.biz>
+ * http://www.intworks.biz/arclcd
+ *
+ * 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 driver was written to be used with the Arc LCD board. Arc uses a
+ * set of KS108 chips that control individual 64x64 LCD matrices. The board
+ * can be paneled in a variety of setups such as 2x1=128x64, 4x4=256x256 and
+ * so on. The interface between the board and the host is TTL based GPIO. The
+ * GPIO requirements are 8 writable data lines and 4+n lines for control. On a
+ * GPIO-less system, the board can be tested by connecting the respective sigs
+ * up to a parallel port connector. The driver requires the IO addresses for
+ * data and control GPIO at load time. It is unable to probe for the
+ * existence of the LCD so it must be told at load time whether it should
+ * be enabled or not.
+ *
+ * Todo:
+ * - testing with 4x4
+ * - testing with interrupt hw
+ *
+ * General notes:
+ * - User must set tuhold. It's in microseconds. According to the 108 spec,
+ *   the hold time is supposed to be at least 1 microsecond.
+ * - User must set num_cols=x num_rows=y, eg: x=2 means 128
+ * - User must set arcfb_enable=1 to enable it
+ * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/tty.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/arcfb.h>
+
+#include <asm/uaccess.h>
+
+#define floor8(a) (a&(~0x07))
+#define floorXres(a,xres) (a&(~(xres - 1)))
+#define iceil8(a) (((int)((a+7)/8))*8)
+#define ceil64(a) (a|0x3F)
+#define ceilXres(a,xres) (a|(xres - 1))
+
+/* ks108 chipset specific defines and code */
+
+#define KS_SET_DPY_START_LINE   0xC0
+#define KS_SET_PAGE_NUM         0xB8
+#define KS_SET_X                0x40
+#define KS_CEHI                 0x01
+#define KS_CELO                 0x00
+#define KS_SEL_CMD              0x08
+#define KS_SEL_DATA             0x00
+#define KS_DPY_ON               0x3F
+#define KS_DPY_OFF              0x3E
+#define KS_INTACK               0x40
+#define KS_CLRINT               0x02
+
+struct arcfb_par {
+        unsigned long dio_addr;
+        unsigned long cio_addr;
+        unsigned long c2io_addr;
+        atomic_t ref_count;
+        unsigned char cslut[9];
+        struct fb_info *info;
+        unsigned int irq;
+        spinlock_t lock;
+};
+
+static struct fb_fix_screeninfo arcfb_fix __initdata = {
+        .id =           "arcfb",
+        .type =         FB_TYPE_PACKED_PIXELS,
+        .visual =       FB_VISUAL_MONO01,
+        .xpanstep =     0,
+        .ypanstep =     1,
+        .ywrapstep =    0,
+        .accel =        FB_ACCEL_NONE,
+};
+
+static struct fb_var_screeninfo arcfb_var __initdata = {
+        .xres           = 128,
+        .yres           = 64,
+        .xres_virtual   = 128,
+        .yres_virtual   = 64,
+        .bits_per_pixel = 1,
+        .nonstd         = 1,
+};
+
+static unsigned long num_cols;
+static unsigned long num_rows;
+static unsigned long dio_addr;
+static unsigned long cio_addr;
+static unsigned long c2io_addr;
+static unsigned long splashval;
+static unsigned long tuhold;
+static unsigned int nosplash;
+static unsigned int arcfb_enable;
+static unsigned int irq;
+
+static DECLARE_WAIT_QUEUE_HEAD(arcfb_waitq);
+
+static void ks108_writeb_ctl(struct arcfb_par *par,
+                                unsigned int chipindex, unsigned char value)
+{
+        unsigned char chipselval = par->cslut[chipindex];
+
+        outb(chipselval|KS_CEHI|KS_SEL_CMD, par->cio_addr);
+        outb(value, par->dio_addr);
+        udelay(tuhold);
+        outb(chipselval|KS_CELO|KS_SEL_CMD, par->cio_addr);
+}
+
+static void ks108_writeb_mainctl(struct arcfb_par *par, unsigned char value)
+{
+
+        outb(value, par->cio_addr);
+        udelay(tuhold);
+}
+
+static unsigned char ks108_readb_ctl2(struct arcfb_par *par)
+{
+        return inb(par->c2io_addr);
+}
+
+static void ks108_writeb_data(struct arcfb_par *par,
+                                unsigned int chipindex, unsigned char value)
+{
+        unsigned char chipselval = par->cslut[chipindex];
+
+        outb(chipselval|KS_CEHI|KS_SEL_DATA, par->cio_addr);
+        outb(value, par->dio_addr);
+        udelay(tuhold);
+        outb(chipselval|KS_CELO|KS_SEL_DATA, par->cio_addr);
+}
+
+static void ks108_set_start_line(struct arcfb_par *par,
+                                unsigned int chipindex, unsigned char y)
+{
+        ks108_writeb_ctl(par, chipindex, KS_SET_DPY_START_LINE|y);
+}
+
+static void ks108_set_yaddr(struct arcfb_par *par,
+                                unsigned int chipindex, unsigned char y)
+{
+        ks108_writeb_ctl(par, chipindex, KS_SET_PAGE_NUM|y);
+}
+
+static void ks108_set_xaddr(struct arcfb_par *par,
+                                unsigned int chipindex, unsigned char x)
+{
+        ks108_writeb_ctl(par, chipindex, KS_SET_X|x);
+}
+
+static void ks108_clear_lcd(struct arcfb_par *par, unsigned int chipindex)
+{
+        int i,j;
+
+        for (i = 0; i <= 8; i++) {
+                ks108_set_yaddr(par, chipindex, i);
+                ks108_set_xaddr(par, chipindex, 0);
+                for (j = 0; j < 64; j++) {
+                        ks108_writeb_data(par, chipindex,
+                                (unsigned char) splashval);
+                }
+        }
+}
+
+/* main arcfb functions */
+
+static int arcfb_open(struct fb_info *info, int user)
+{
+        struct arcfb_par *par = info->par;
+
+        atomic_inc(&par->ref_count);
+        return 0;
+}
+
+static int arcfb_release(struct fb_info *info, int user)
+{
+        struct arcfb_par *par = info->par;
+        int count = atomic_read(&par->ref_count);
+
+        if (!count)
+                return -EINVAL;
+        atomic_dec(&par->ref_count);
+        return 0;
+}
+
+static int arcfb_pan_display(struct fb_var_screeninfo *var,
+                                struct fb_info *info)
+{
+        int i;
+        struct arcfb_par *par = info->par;
+
+        if ((var->vmode & FB_VMODE_YWRAP) && (var->yoffset < 64)
+                && (info->var.yres <= 64)) {
+                for (i = 0; i < num_cols; i++) {
+                        ks108_set_start_line(par, i, var->yoffset);
+                }
+                info->var.yoffset = var->yoffset;
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+static irqreturn_t arcfb_interrupt(int vec, void *dev_instance,
+                struct pt_regs *regs)
+{
+        struct fb_info *info = dev_instance;
+        unsigned char ctl2status;
+        struct arcfb_par *par = info->par;
+
+        ctl2status = ks108_readb_ctl2(par);
+
+        if (!(ctl2status & KS_INTACK)) /* not arc generated interrupt */
+                return IRQ_NONE;
+
+        ks108_writeb_mainctl(par, KS_CLRINT);
+
+        spin_lock(&par->lock);
+        if (waitqueue_active(&arcfb_waitq)) {
+                wake_up(&arcfb_waitq);
+        }
+        spin_unlock(&par->lock);
+
+        return IRQ_HANDLED;
+}
+
+/*
+ * here we handle a specific page on the lcd. the complexity comes from
+ * the fact that the fb is laidout in 8xX vertical columns. we extract
+ * each write of 8 vertical pixels. then we shift out as we move along
+ * X. That's what rightshift does. bitmask selects the desired input bit.
+ */
+static void arcfb_lcd_update_page(struct arcfb_par *par, unsigned int upper,
+                unsigned int left, unsigned int right, unsigned int distance)
+{
+        unsigned char *src;
+        unsigned int xindex, yindex, chipindex, linesize;
+        int i, count;
+        unsigned char val;
+        unsigned char bitmask, rightshift;
+
+        xindex = left >> 6;
+        yindex = upper >> 6;
+        chipindex = (xindex + (yindex*num_cols));
+
+        ks108_set_yaddr(par, chipindex, upper/8);
+
+        linesize = par->info->var.xres/8;
+        src = par->info->screen_base + (left/8) + (upper * linesize);
+        ks108_set_xaddr(par, chipindex, left);
+
+        bitmask=1;
+        rightshift=0;
+        while (left <= right) {
+                val = 0;
+                for (i = 0; i < 8; i++) {
+                        if ( i > rightshift) {
+                                val |= (*(src + (i*linesize)) & bitmask)
+                                                << (i - rightshift);
+                        } else {
+                                val |= (*(src + (i*linesize)) & bitmask)
+                                                 >> (rightshift - i);
+                        }
+                }
+                ks108_writeb_data(par, chipindex, val);
+                left++;
+                count++;
+                if (bitmask == 0x80) {
+                        bitmask = 1;
+                        src++;
+                        rightshift=0;
+                } else {
+                        bitmask <<= 1;
+                        rightshift++;
+                }
+        }
+}
+
+/*
+ * here we handle the entire vertical page of the update. we write across
+ * lcd chips. update_page uses the upper/left values to decide which
+ * chip to select for the right. upper is needed for setting the page
+ * desired for the write.
+ */
+static void arcfb_lcd_update_vert(struct arcfb_par *par, unsigned int top,
+                unsigned int bottom, unsigned int left, unsigned int right)
+{
+        unsigned int distance, upper, lower;
+
+        distance = (bottom - top) + 1;
+        upper = top;
+        lower = top + 7;
+
+        while (distance > 0) {
+                distance -= 8;
+                arcfb_lcd_update_page(par, upper, left, right, 8);
+                upper = lower + 1;
+                lower = upper + 7;
+        }
+}
+
+/*
+ * here we handle horizontal blocks for the update. update_vert will
+ * handle spaning multiple pages. we break out each horizontal
+ * block in to individual blocks no taller than 64 pixels.
+ */
+static void arcfb_lcd_update_horiz(struct arcfb_par *par, unsigned int left,
+                        unsigned int right, unsigned int top, unsigned int h)
+{
+        unsigned int distance, upper, lower;
+
+        distance = h;
+        upper = floor8(top);
+        lower = min(upper + distance - 1, ceil64(upper));
+
+        while (distance > 0) {
+                distance -= ((lower - upper) + 1 );
+                arcfb_lcd_update_vert(par, upper, lower, left, right);
+                upper = lower + 1;
+                lower = min(upper + distance - 1, ceil64(upper));
+        }
+}
+
+/*
+ * here we start the process of spliting out the fb update into
+ * individual blocks of pixels. we end up spliting into 64x64 blocks
+ * and finally down to 64x8 pages.
+ */
+static void arcfb_lcd_update(struct arcfb_par *par, unsigned int dx,
+                        unsigned int dy, unsigned int w, unsigned int h)
+{
+        unsigned int left, right, distance, y;
+
+        /* align the request first */
+        y = floor8(dy);
+        h += dy - y;
+        h = iceil8(h);
+
+        distance = w;
+        left = dx;
+        right = min(left + w - 1, ceil64(left));
+
+        while (distance > 0) {
+                arcfb_lcd_update_horiz(par, left, right, y, h);
+                distance -= ((right - left) + 1);
+                left = right + 1;
+                right = min(left + distance - 1, ceil64(left));
+        }
+}
+
+void arcfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+        struct arcfb_par *par = info->par;
+
+        cfb_fillrect(info, rect);
+
+        /* update the physical lcd */
+        arcfb_lcd_update(par, rect->dx, rect->dy, rect->width, rect->height);
+}
+
+void arcfb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+        struct arcfb_par *par = info->par;
+
+        cfb_copyarea(info, area);
+
+        /* update the physical lcd */
+        arcfb_lcd_update(par, area->dx, area->dy, area->width, area->height);
+}
+
+void arcfb_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+        struct arcfb_par *par = info->par;
+
+        cfb_imageblit(info, image);
+
+        /* update the physical lcd */
+        arcfb_lcd_update(par, image->dx, image->dy, image->width,
+                                image->height);
+}
+
+static int arcfb_ioctl(struct inode *inode, struct file *file,
+                          unsigned int cmd, unsigned long arg,
+                          struct fb_info *info)
+{
+        void __user *argp = (void __user *)arg;
+        struct arcfb_par *par = info->par;
+        unsigned long flags;
+
+        switch (cmd) {
+                case FBIO_WAITEVENT:
+                {
+                        DEFINE_WAIT(wait);
+                        /* illegal to wait on arc if no irq will occur */
+                        if (!par->irq)
+                                return -EINVAL;
+
+                        /* wait until the Arc has generated an interrupt
+                         * which will wake us up */
+                        spin_lock_irqsave(&par->lock, flags);
+                        prepare_to_wait(&arcfb_waitq, &wait,
+                                        TASK_INTERRUPTIBLE);
+                        spin_unlock_irqrestore(&par->lock, flags);
+                        schedule();
+                        finish_wait(&arcfb_waitq, &wait);
+                }
+                case FBIO_GETCONTROL2:
+                {
+                        unsigned char ctl2;
+
+                        ctl2 = ks108_readb_ctl2(info->par);
+                        if (copy_to_user(argp, &ctl2, sizeof(ctl2)))
+                                return -EFAULT;
+                        return 0;
+                }
+                default:
+                        return -EINVAL;
+        }
+}
+
+/*
+ * this is the access path from userspace. they can seek and write to
+ * the fb. it's inefficient for them to do anything less than 64*8
+ * writes since we update the lcd in each write() anyway.
+ */
+static ssize_t arcfb_write(struct file *file, const char *buf, size_t count,
+                                loff_t *ppos)
+{
+        /* modded from epson 1355 */
+
+        struct inode *inode;
+        int fbidx;
+        struct fb_info *info;
+        unsigned long p;
+        int err=-EINVAL;
+        unsigned int fbmemlength,x,y,w,h, bitppos, startpos, endpos, bitcount;
+        struct arcfb_par *par;
+        unsigned int xres;
+
+        p = *ppos;
+        inode = file->f_dentry->d_inode;
+        fbidx = iminor(inode);
+        info = registered_fb[fbidx];
+        par = info->par;
+
+        if (!info || !info->screen_base)
+                return -ENODEV;
+
+        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;
+        }
+
+
+        bitppos = p*8;
+        startpos = floorXres(bitppos, xres);
+        endpos = ceilXres((bitppos + (count*8)), xres);
+        bitcount = endpos - startpos;
+
+        x = startpos % xres;
+        y = startpos / xres;
+        w = xres;
+        h = bitcount / xres;
+        arcfb_lcd_update(par, x, y, w, h);
+
+        if (count)
+                return count;
+        return err;
+}
+
+static void arcfb_platform_release(struct device *device)
+{
+}
+
+static struct fb_ops arcfb_ops = {
+        .owner          = THIS_MODULE,
+        .fb_open        = arcfb_open,
+        .fb_write       = arcfb_write,
+        .fb_release     = arcfb_release,
+        .fb_pan_display = arcfb_pan_display,
+        .fb_fillrect    = arcfb_fillrect,
+        .fb_copyarea    = arcfb_copyarea,
+        .fb_imageblit   = arcfb_imageblit,
+        .fb_cursor      = soft_cursor,
+        .fb_ioctl       = arcfb_ioctl,
+};
+
+static int __init arcfb_probe(struct device *device)
+{
+        struct platform_device *dev = to_platform_device(device);
+        struct fb_info *info;
+        int retval = -ENOMEM;
+        int videomemorysize;
+        unsigned char *videomemory;
+        struct arcfb_par *par;
+        int i;
+
+        videomemorysize = (((64*64)*num_cols)*num_rows)/8;
+
+        /* We need a flat backing store for the Arc's
+           less-flat actual paged framebuffer */
+        if (!(videomemory = vmalloc(videomemorysize)))
+                return retval;
+
+        memset(videomemory, 0, videomemorysize);
+
+        info = framebuffer_alloc(sizeof(struct arcfb_par), &dev->dev);
+        if (!info)
+                goto err;
+
+        info->screen_base = (char __iomem *)videomemory;
+        info->fbops = &arcfb_ops;
+
+        info->var = arcfb_var;
+        info->fix = arcfb_fix;
+        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;
+        par->cslut[0] = 0x00;
+        par->cslut[1] = 0x06;
+        info->flags = FBINFO_FLAG_DEFAULT;
+        spin_lock_init(&par->lock);
+        retval = register_framebuffer(info);
+        if (retval < 0)
+                goto err1;
+        dev_set_drvdata(&dev->dev, info);
+        if (irq) {
+                par->irq = irq;
+                if (request_irq(par->irq, &arcfb_interrupt, SA_SHIRQ,
+                                "arcfb", info)) {
+                        printk(KERN_INFO
+                                "arcfb: Failed req IRQ %d\n", par->irq);
+                        goto err1;
+                }
+        }
+        printk(KERN_INFO
+               "fb%d: Arc frame buffer device, using %dK of video memory\n",
+               info->node, videomemorysize >> 10);
+
+        /* this inits the lcd but doesn't clear dirty pixels */
+        for (i = 0; i < num_cols * num_rows; i++) {
+                ks108_writeb_ctl(par, i, KS_DPY_OFF);
+                ks108_set_start_line(par, i, 0);
+                ks108_set_yaddr(par, i, 0);
+                ks108_set_xaddr(par, i, 0);
+                ks108_writeb_ctl(par, i, KS_DPY_ON);
+        }
+
+        /* if we were told to splash the screen, we just clear it */
+        if (!nosplash) {
+                for (i = 0; i < num_cols * num_rows; i++) {
+                        printk(KERN_INFO "fb%d: splashing lcd %d\n",
+                                info->node, i);
+                        ks108_set_start_line(par, i, 0);
+                        ks108_clear_lcd(par, i);
+                }
+        }
+
+        return 0;
+err1:
+        framebuffer_release(info);
+err:
+        vfree(videomemory);
+        return retval;
+}
+
+static int arcfb_remove(struct device *device)
+{
+        struct fb_info *info = dev_get_drvdata(device);
+
+        if (info) {
+                unregister_framebuffer(info);
+                vfree(info->screen_base);
+                framebuffer_release(info);
+        }
+        return 0;
+}
+
+static struct device_driver arcfb_driver = {
+        .name   = "arcfb",
+        .bus    = &platform_bus_type,
+        .probe  = arcfb_probe,
+        .remove = arcfb_remove,
+};
+
+static struct platform_device arcfb_device = {
+        .name   = "arcfb",
+        .id     = 0,
+        .dev    = {
+                .release = arcfb_platform_release,
+        }
+};
+
+static int __init arcfb_init(void)
+{
+        int ret;
+
+        if (!arcfb_enable)
+                return -ENXIO;
+
+        ret = driver_register(&arcfb_driver);
+        if (!ret) {
+                ret = platform_device_register(&arcfb_device);
+                if (ret)
+                        driver_unregister(&arcfb_driver);
+        }
+        return ret;
+
+}
+
+static void __exit arcfb_exit(void)
+{
+        platform_device_unregister(&arcfb_device);
+        driver_unregister(&arcfb_driver);
+}
+
+module_param(num_cols, ulong, 0);
+MODULE_PARM_DESC(num_cols, "Num horiz panels, eg: 2 = 128 bit wide");
+module_param(num_rows, ulong, 0);
+MODULE_PARM_DESC(num_rows, "Num vert panels, eg: 1 = 64 bit high");
+module_param(nosplash, uint, 0);
+MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
+module_param(arcfb_enable, uint, 0);
+MODULE_PARM_DESC(arcfb_enable, "Enable communication with Arc 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: 0xFF is black, 0x00 is green");
+module_param(tuhold, ulong, 0);
+MODULE_PARM_DESC(tuhold, "Time to hold between strobing data to Arc board");
+module_param(irq, uint, 0);
+MODULE_PARM_DESC(irq, "IRQ for the Arc board");
+
+module_init(arcfb_init);
+module_exit(arcfb_exit);
+
+MODULE_DESCRIPTION("fbdev driver for Arc monochrome LCD board");
+MODULE_AUTHOR("Jaya Kumar");
+MODULE_LICENSE("GPL");
+