/* * 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); /* * 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; } 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_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; memset(cfag12864b_buffer, 0, CFAG12864B_SIZE); 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 <maxextreme@gmail.com>"); MODULE_DESCRIPTION("cfag12864b LCD driver");