[PATCH] drivers: add LCD support

Add support for auxiliary displays, the ks0108 LCD controller, the
cfag12864b LCD and adds a framebuffer device: cfag12864bfb.

- Add a "auxdisplay/" folder in "drivers/" for auxiliary display
  drivers.

- Add support for the ks0108 LCD Controller as a device driver.  (uses
  parport interface)

- Add support for the cfag12864b LCD as a device driver.  (uses ks0108
  LCD Controller driver)

- Add a framebuffer device called cfag12864bfb.  (uses cfag12864b LCD
  driver)

- Add the usual Documentation, includes, Makefiles, Kconfigs,
  MAINTAINERS, CREDITS...

- Miguel Ojeda will maintain all the stuff above.

[rdunlap@xenotime.net: workqueue fixups]
[akpm@osdl.org: kconfig fix]
Signed-off-by: Miguel Ojeda Sandonis <maxextreme@gmail.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 383 insertions, 0 deletions

diff --git a/drivers/auxdisplay/cfag12864b.c b/drivers/auxdisplay/cfag12864b.c
new file mode 100644
index 000000000000..889583dfc1a6
--- /dev/null
+++ b/drivers/auxdisplay/cfag12864b.c
@@ -0,0 +1,383 @@
+/*
+ *    Filename: cfag12864b.c
+ *     Version: 0.1.0
+ * Description: cfag12864b LCD driver
+ *     License: GPLv2
+ *     Depends: ks0108
+ *
+ *      Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
+ *        Date: 2006-10-31
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program 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 program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <linux/workqueue.h>
+#include <linux/ks0108.h>
+#include <linux/cfag12864b.h>
+
+
+#define CFAG12864B_NAME "cfag12864b"
+
+/*
+ * Module Parameters
+ */
+
+static unsigned int cfag12864b_rate = CONFIG_CFAG12864B_RATE;
+module_param(cfag12864b_rate, uint, S_IRUGO);
+MODULE_PARM_DESC(cfag12864b_rate,
+        "Refresh rate (hertzs)");
+
+unsigned int cfag12864b_getrate(void)
+{
+        return cfag12864b_rate;
+}
+
+/*
+ * cfag12864b Commands
+ *
+ *      E = Enable signal
+ *              Everytime E switch from low to high,
+ *              cfag12864b/ks0108 reads the command/data.
+ *
+ *      CS1 = First ks0108controller.
+ *              If high, the first ks0108 controller receives commands/data.
+ *
+ *      CS2 = Second ks0108 controller
+ *              If high, the second ks0108 controller receives commands/data.
+ *
+ *      DI = Data/Instruction
+ *              If low, cfag12864b will expect commands.
+ *              If high, cfag12864b will expect data.
+ *
+ */
+
+#define bit(n) (((unsigned char)1)<<(n))
+
+#define CFAG12864B_BIT_E        (0)
+#define CFAG12864B_BIT_CS1      (2)
+#define CFAG12864B_BIT_CS2      (1)
+#define CFAG12864B_BIT_DI       (3)
+
+static unsigned char cfag12864b_state;
+
+static void cfag12864b_set(void)
+{
+        ks0108_writecontrol(cfag12864b_state);
+}
+
+static void cfag12864b_setbit(unsigned char state, unsigned char n)
+{
+        if (state)
+                cfag12864b_state |= bit(n);
+        else
+                cfag12864b_state &= ~bit(n);
+}
+
+static void cfag12864b_e(unsigned char state)
+{
+        cfag12864b_setbit(state, CFAG12864B_BIT_E);
+        cfag12864b_set();
+}
+
+static void cfag12864b_cs1(unsigned char state)
+{
+        cfag12864b_setbit(state, CFAG12864B_BIT_CS1);
+}
+
+static void cfag12864b_cs2(unsigned char state)
+{
+        cfag12864b_setbit(state, CFAG12864B_BIT_CS2);
+}
+
+static void cfag12864b_di(unsigned char state)
+{
+        cfag12864b_setbit(state, CFAG12864B_BIT_DI);
+}
+
+static void cfag12864b_setcontrollers(unsigned char first,
+        unsigned char second)
+{
+        if (first)
+                cfag12864b_cs1(0);
+        else
+                cfag12864b_cs1(1);
+
+        if (second)
+                cfag12864b_cs2(0);
+        else
+                cfag12864b_cs2(1);
+}
+
+static void cfag12864b_controller(unsigned char which)
+{
+        if (which == 0)
+                cfag12864b_setcontrollers(1, 0);
+        else if (which == 1)
+                cfag12864b_setcontrollers(0, 1);
+}
+
+static void cfag12864b_displaystate(unsigned char state)
+{
+        cfag12864b_di(0);
+        cfag12864b_e(1);
+        ks0108_displaystate(state);
+        cfag12864b_e(0);
+}
+
+static void cfag12864b_address(unsigned char address)
+{
+        cfag12864b_di(0);
+        cfag12864b_e(1);
+        ks0108_address(address);
+        cfag12864b_e(0);
+}
+
+static void cfag12864b_page(unsigned char page)
+{
+        cfag12864b_di(0);
+        cfag12864b_e(1);
+        ks0108_page(page);
+        cfag12864b_e(0);
+}
+
+static void cfag12864b_startline(unsigned char startline)
+{
+        cfag12864b_di(0);
+        cfag12864b_e(1);
+        ks0108_startline(startline);
+        cfag12864b_e(0);
+}
+
+static void cfag12864b_writebyte(unsigned char byte)
+{
+        cfag12864b_di(1);
+        cfag12864b_e(1);
+        ks0108_writedata(byte);
+        cfag12864b_e(0);
+}
+
+static void cfag12864b_nop(void)
+{
+        cfag12864b_startline(0);
+}
+
+/*
+ * cfag12864b Internal Commands
+ */
+
+static void cfag12864b_on(void)
+{
+        cfag12864b_setcontrollers(1, 1);
+        cfag12864b_displaystate(1);
+}
+
+static void cfag12864b_off(void)
+{
+        cfag12864b_setcontrollers(1, 1);
+        cfag12864b_displaystate(0);
+}
+
+static void cfag12864b_clear(void)
+{
+        unsigned char i, j;
+
+        cfag12864b_setcontrollers(1, 1);
+        for (i = 0; i < CFAG12864B_PAGES; i++) {
+                cfag12864b_page(i);
+                cfag12864b_address(0);
+                for (j = 0; j < CFAG12864B_ADDRESSES; j++)
+                        cfag12864b_writebyte(0);
+        }
+}
+
+/*
+ * Update work
+ */
+
+unsigned char *cfag12864b_buffer;
+static unsigned char *cfag12864b_cache;
+static DEFINE_MUTEX(cfag12864b_mutex);
+static unsigned char cfag12864b_updating;
+static void cfag12864b_update(struct work_struct *delayed_work);
+static struct workqueue_struct *cfag12864b_workqueue;
+static DECLARE_DELAYED_WORK(cfag12864b_work, cfag12864b_update);
+
+static void cfag12864b_queue(void)
+{
+        queue_delayed_work(cfag12864b_workqueue, &cfag12864b_work,
+                HZ / cfag12864b_rate);
+}
+
+unsigned char cfag12864b_enable(void)
+{
+        unsigned char ret;
+
+        mutex_lock(&cfag12864b_mutex);
+
+        if (!cfag12864b_updating) {
+                cfag12864b_updating = 1;
+                cfag12864b_queue();
+                ret = 0;
+        } else
+                ret = 1;
+
+        mutex_unlock(&cfag12864b_mutex);
+
+        return ret;
+}
+
+void cfag12864b_disable(void)
+{
+        mutex_lock(&cfag12864b_mutex);
+
+        if (cfag12864b_updating) {
+                cfag12864b_updating = 0;
+                cancel_delayed_work(&cfag12864b_work);
+                flush_workqueue(cfag12864b_workqueue);
+        }
+
+        mutex_unlock(&cfag12864b_mutex);
+}
+
+unsigned char cfag12864b_isenabled(void)
+{
+        return cfag12864b_updating;
+}
+
+static void cfag12864b_update(struct work_struct *work)
+{
+        unsigned char c;
+        unsigned short i, j, k, b;
+
+        if (memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) {
+                for (i = 0; i < CFAG12864B_CONTROLLERS; i++) {
+                        cfag12864b_controller(i);
+                        cfag12864b_nop();
+                        for (j = 0; j < CFAG12864B_PAGES; j++) {
+                                cfag12864b_page(j);
+                                cfag12864b_nop();
+                                cfag12864b_address(0);
+                                cfag12864b_nop();
+                                for (k = 0; k < CFAG12864B_ADDRESSES; k++) {
+                                        for (c = 0, b = 0; b < 8; b++)
+                                                if (cfag12864b_buffer
+                                                        [i * CFAG12864B_ADDRESSES / 8
+                                                        + k / 8 + (j * 8 + b) *
+                                                        CFAG12864B_WIDTH / 8]
+                                                        & bit(k % 8))
+                                                        c |= bit(b);
+                                        cfag12864b_writebyte(c);
+                                }
+                        }
+                }
+
+                memcpy(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE);
+        }
+
+        if (cfag12864b_updating)
+                cfag12864b_queue();
+}
+
+/*
+ * cfag12864b Exported Symbols
+ */
+
+EXPORT_SYMBOL_GPL(cfag12864b_buffer);
+EXPORT_SYMBOL_GPL(cfag12864b_getrate);
+EXPORT_SYMBOL_GPL(cfag12864b_enable);
+EXPORT_SYMBOL_GPL(cfag12864b_disable);
+EXPORT_SYMBOL_GPL(cfag12864b_isenabled);
+
+/*
+ * Module Init & Exit
+ */
+
+static int __init cfag12864b_init(void)
+{
+        int ret = -EINVAL;
+
+        if (PAGE_SIZE < CFAG12864B_SIZE) {
+                printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+                        "page size (%i) < cfag12864b size (%i)\n",
+                        (unsigned int)PAGE_SIZE, CFAG12864B_SIZE);
+                ret = -ENOMEM;
+                goto none;
+        }
+
+        cfag12864b_buffer = (unsigned char *) __get_free_page(GFP_KERNEL);
+        if (cfag12864b_buffer == NULL) {
+                printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+                        "can't get a free page\n");
+                ret = -ENOMEM;
+                goto none;
+        }
+
+        cfag12864b_cache = kmalloc(sizeof(unsigned char) *
+                CFAG12864B_SIZE, GFP_KERNEL);
+        if (cfag12864b_buffer == NULL) {
+                printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
+                        "can't alloc cache buffer (%i bytes)\n",
+                        CFAG12864B_SIZE);
+                ret = -ENOMEM;
+                goto bufferalloced;
+        }
+
+        cfag12864b_workqueue = create_singlethread_workqueue(CFAG12864B_NAME);
+        if (cfag12864b_workqueue == NULL)
+                goto cachealloced;
+
+        memset(cfag12864b_buffer, 0, CFAG12864B_SIZE);
+
+        cfag12864b_clear();
+        cfag12864b_on();
+
+        return 0;
+
+cachealloced:
+        kfree(cfag12864b_cache);
+
+bufferalloced:
+        free_page((unsigned long) cfag12864b_buffer);
+
+none:
+        return ret;
+}
+
+static void __exit cfag12864b_exit(void)
+{
+        cfag12864b_disable();
+        cfag12864b_off();
+        destroy_workqueue(cfag12864b_workqueue);
+        kfree(cfag12864b_cache);
+        free_page((unsigned long) cfag12864b_buffer);
+}
+
+module_init(cfag12864b_init);
+module_exit(cfag12864b_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Miguel Ojeda Sandonis <maxextreme@gmail.com>");
+MODULE_DESCRIPTION("cfag12864b LCD driver");