diff options
Diffstat (limited to 'drivers/auxdisplay/cfag12864b.c')
| -rw-r--r-- | drivers/auxdisplay/cfag12864b.c | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/drivers/auxdisplay/cfag12864b.c b/drivers/auxdisplay/cfag12864b.c new file mode 100644 index 0000000..eacb175 --- /dev/null +++ b/drivers/auxdisplay/cfag12864b.c @@ -0,0 +1,393 @@ +/* + * 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/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"); |
