| /* |
| * 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"); |