drivers/auxdisplay/cfag12864b.c - third_party/linux - Git at Google

 /*
  *    Filename: cfag12864b.c
  *     Version: 0.1.0
  * Description: cfag12864b LCD driver
  *     License: GPLv2
  *     Depends: ks0108
  *
  *      Author: Copyright (C) Miguel Ojeda Sandonis
  *        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/slab.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);

 /*
  * Is the module inited?
  */

 static unsigned char cfag12864b_inited;
 unsigned char cfag12864b_isinited(void)
 {
 	return cfag12864b_inited;
 }
 EXPORT_SYMBOL_GPL(cfag12864b_isinited);

 /*
  * Module Init & Exit
  */

 static int __init cfag12864b_init(void)
 {
 	int ret = -EINVAL;

 	/* ks0108_init() must be called first */
 	if (!ks0108_isinited()) {
 		printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
 			"ks0108 is not initialized\n");
 		goto none;
 	}
 	BUILD_BUG_ON(PAGE_SIZE < CFAG12864B_SIZE);

 	cfag12864b_buffer = (unsigned char *) get_zeroed_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_cache == 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;

 	cfag12864b_clear();
 	cfag12864b_on();

 	cfag12864b_inited = 1;
 	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 <miguel.ojeda.sandonis@gmail.com>");
 MODULE_DESCRIPTION("cfag12864b LCD driver");
	/*
	* Filename: cfag12864b.c
	* Version: 0.1.0
	* Description: cfag12864b LCD driver
	* License: GPLv2
	* Depends: ks0108
	*
	* Author: Copyright (C) Miguel Ojeda Sandonis
	* 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/slab.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);

	/*
	* Is the module inited?
	*/

	static unsigned char cfag12864b_inited;
	unsigned char cfag12864b_isinited(void)
	{
	return cfag12864b_inited;
	}
	EXPORT_SYMBOL_GPL(cfag12864b_isinited);

	/*
	* Module Init & Exit
	*/

	static int __init cfag12864b_init(void)
	{
	int ret = -EINVAL;

	/* ks0108_init() must be called first */
	if (!ks0108_isinited()) {
	printk(KERN_ERR CFAG12864B_NAME ": ERROR: "
	"ks0108 is not initialized\n");
	goto none;
	}
	BUILD_BUG_ON(PAGE_SIZE < CFAG12864B_SIZE);

	cfag12864b_buffer = (unsigned char *) get_zeroed_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_cache == 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;

	cfag12864b_clear();
	cfag12864b_on();

	cfag12864b_inited = 1;
	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 <miguel.ojeda.sandonis@gmail.com>");
	MODULE_DESCRIPTION("cfag12864b LCD driver");