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380 lines
7.5 KiB
380 lines
7.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Filename: cfag12864b.c |
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* Version: 0.1.0 |
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* Description: cfag12864b LCD driver |
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* Depends: ks0108 |
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* |
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* Author: Copyright (C) Miguel Ojeda <[email protected]> |
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* Date: 2006-10-31 |
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*/ |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/fs.h> |
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#include <linux/slab.h> |
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#include <linux/cdev.h> |
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#include <linux/delay.h> |
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#include <linux/device.h> |
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#include <linux/jiffies.h> |
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#include <linux/mutex.h> |
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#include <linux/uaccess.h> |
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#include <linux/vmalloc.h> |
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#include <linux/workqueue.h> |
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#include <linux/ks0108.h> |
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#include <linux/cfag12864b.h> |
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#define CFAG12864B_NAME "cfag12864b" |
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/* |
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* Module Parameters |
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*/ |
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static unsigned int cfag12864b_rate = CONFIG_CFAG12864B_RATE; |
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module_param(cfag12864b_rate, uint, S_IRUGO); |
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MODULE_PARM_DESC(cfag12864b_rate, |
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"Refresh rate (hertz)"); |
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unsigned int cfag12864b_getrate(void) |
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{ |
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return cfag12864b_rate; |
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} |
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/* |
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* cfag12864b Commands |
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* |
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* E = Enable signal |
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* Every time E switch from low to high, |
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* cfag12864b/ks0108 reads the command/data. |
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* |
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* CS1 = First ks0108controller. |
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* If high, the first ks0108 controller receives commands/data. |
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* |
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* CS2 = Second ks0108 controller |
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* If high, the second ks0108 controller receives commands/data. |
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* |
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* DI = Data/Instruction |
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* If low, cfag12864b will expect commands. |
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* If high, cfag12864b will expect data. |
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* |
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*/ |
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#define bit(n) (((unsigned char)1)<<(n)) |
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#define CFAG12864B_BIT_E (0) |
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#define CFAG12864B_BIT_CS1 (2) |
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#define CFAG12864B_BIT_CS2 (1) |
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#define CFAG12864B_BIT_DI (3) |
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static unsigned char cfag12864b_state; |
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static void cfag12864b_set(void) |
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{ |
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ks0108_writecontrol(cfag12864b_state); |
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} |
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static void cfag12864b_setbit(unsigned char state, unsigned char n) |
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{ |
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if (state) |
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cfag12864b_state |= bit(n); |
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else |
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cfag12864b_state &= ~bit(n); |
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} |
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static void cfag12864b_e(unsigned char state) |
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{ |
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cfag12864b_setbit(state, CFAG12864B_BIT_E); |
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cfag12864b_set(); |
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} |
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static void cfag12864b_cs1(unsigned char state) |
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{ |
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cfag12864b_setbit(state, CFAG12864B_BIT_CS1); |
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} |
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static void cfag12864b_cs2(unsigned char state) |
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{ |
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cfag12864b_setbit(state, CFAG12864B_BIT_CS2); |
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} |
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static void cfag12864b_di(unsigned char state) |
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{ |
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cfag12864b_setbit(state, CFAG12864B_BIT_DI); |
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} |
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static void cfag12864b_setcontrollers(unsigned char first, |
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unsigned char second) |
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{ |
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if (first) |
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cfag12864b_cs1(0); |
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else |
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cfag12864b_cs1(1); |
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if (second) |
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cfag12864b_cs2(0); |
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else |
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cfag12864b_cs2(1); |
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} |
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static void cfag12864b_controller(unsigned char which) |
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{ |
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if (which == 0) |
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cfag12864b_setcontrollers(1, 0); |
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else if (which == 1) |
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cfag12864b_setcontrollers(0, 1); |
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} |
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static void cfag12864b_displaystate(unsigned char state) |
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{ |
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cfag12864b_di(0); |
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cfag12864b_e(1); |
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ks0108_displaystate(state); |
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cfag12864b_e(0); |
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} |
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static void cfag12864b_address(unsigned char address) |
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{ |
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cfag12864b_di(0); |
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cfag12864b_e(1); |
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ks0108_address(address); |
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cfag12864b_e(0); |
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} |
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static void cfag12864b_page(unsigned char page) |
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{ |
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cfag12864b_di(0); |
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cfag12864b_e(1); |
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ks0108_page(page); |
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cfag12864b_e(0); |
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} |
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static void cfag12864b_startline(unsigned char startline) |
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{ |
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cfag12864b_di(0); |
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cfag12864b_e(1); |
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ks0108_startline(startline); |
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cfag12864b_e(0); |
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} |
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static void cfag12864b_writebyte(unsigned char byte) |
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{ |
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cfag12864b_di(1); |
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cfag12864b_e(1); |
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ks0108_writedata(byte); |
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cfag12864b_e(0); |
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} |
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static void cfag12864b_nop(void) |
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{ |
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cfag12864b_startline(0); |
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} |
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/* |
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* cfag12864b Internal Commands |
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*/ |
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static void cfag12864b_on(void) |
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{ |
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cfag12864b_setcontrollers(1, 1); |
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cfag12864b_displaystate(1); |
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} |
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static void cfag12864b_off(void) |
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{ |
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cfag12864b_setcontrollers(1, 1); |
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cfag12864b_displaystate(0); |
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} |
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static void cfag12864b_clear(void) |
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{ |
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unsigned char i, j; |
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cfag12864b_setcontrollers(1, 1); |
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for (i = 0; i < CFAG12864B_PAGES; i++) { |
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cfag12864b_page(i); |
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cfag12864b_address(0); |
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for (j = 0; j < CFAG12864B_ADDRESSES; j++) |
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cfag12864b_writebyte(0); |
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} |
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} |
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/* |
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* Update work |
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*/ |
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unsigned char *cfag12864b_buffer; |
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static unsigned char *cfag12864b_cache; |
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static DEFINE_MUTEX(cfag12864b_mutex); |
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static unsigned char cfag12864b_updating; |
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static void cfag12864b_update(struct work_struct *delayed_work); |
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static struct workqueue_struct *cfag12864b_workqueue; |
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static DECLARE_DELAYED_WORK(cfag12864b_work, cfag12864b_update); |
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static void cfag12864b_queue(void) |
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{ |
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queue_delayed_work(cfag12864b_workqueue, &cfag12864b_work, |
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HZ / cfag12864b_rate); |
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} |
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unsigned char cfag12864b_enable(void) |
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{ |
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unsigned char ret; |
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mutex_lock(&cfag12864b_mutex); |
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if (!cfag12864b_updating) { |
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cfag12864b_updating = 1; |
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cfag12864b_queue(); |
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ret = 0; |
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} else |
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ret = 1; |
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mutex_unlock(&cfag12864b_mutex); |
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return ret; |
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} |
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void cfag12864b_disable(void) |
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{ |
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mutex_lock(&cfag12864b_mutex); |
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if (cfag12864b_updating) { |
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cfag12864b_updating = 0; |
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cancel_delayed_work(&cfag12864b_work); |
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flush_workqueue(cfag12864b_workqueue); |
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} |
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mutex_unlock(&cfag12864b_mutex); |
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} |
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unsigned char cfag12864b_isenabled(void) |
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{ |
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return cfag12864b_updating; |
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} |
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static void cfag12864b_update(struct work_struct *work) |
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{ |
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unsigned char c; |
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unsigned short i, j, k, b; |
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if (memcmp(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE)) { |
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for (i = 0; i < CFAG12864B_CONTROLLERS; i++) { |
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cfag12864b_controller(i); |
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cfag12864b_nop(); |
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for (j = 0; j < CFAG12864B_PAGES; j++) { |
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cfag12864b_page(j); |
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cfag12864b_nop(); |
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cfag12864b_address(0); |
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cfag12864b_nop(); |
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for (k = 0; k < CFAG12864B_ADDRESSES; k++) { |
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for (c = 0, b = 0; b < 8; b++) |
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if (cfag12864b_buffer |
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[i * CFAG12864B_ADDRESSES / 8 |
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+ k / 8 + (j * 8 + b) * |
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CFAG12864B_WIDTH / 8] |
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& bit(k % 8)) |
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c |= bit(b); |
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cfag12864b_writebyte(c); |
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} |
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} |
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} |
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memcpy(cfag12864b_cache, cfag12864b_buffer, CFAG12864B_SIZE); |
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} |
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if (cfag12864b_updating) |
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cfag12864b_queue(); |
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} |
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/* |
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* cfag12864b Exported Symbols |
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*/ |
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EXPORT_SYMBOL_GPL(cfag12864b_buffer); |
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EXPORT_SYMBOL_GPL(cfag12864b_getrate); |
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EXPORT_SYMBOL_GPL(cfag12864b_enable); |
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EXPORT_SYMBOL_GPL(cfag12864b_disable); |
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EXPORT_SYMBOL_GPL(cfag12864b_isenabled); |
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/* |
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* Is the module inited? |
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*/ |
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static unsigned char cfag12864b_inited; |
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unsigned char cfag12864b_isinited(void) |
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{ |
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return cfag12864b_inited; |
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} |
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EXPORT_SYMBOL_GPL(cfag12864b_isinited); |
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/* |
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* Module Init & Exit |
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*/ |
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static int __init cfag12864b_init(void) |
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{ |
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int ret = -EINVAL; |
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/* ks0108_init() must be called first */ |
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if (!ks0108_isinited()) { |
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printk(KERN_ERR CFAG12864B_NAME ": ERROR: " |
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"ks0108 is not initialized\n"); |
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goto none; |
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} |
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BUILD_BUG_ON(PAGE_SIZE < CFAG12864B_SIZE); |
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cfag12864b_buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL); |
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if (cfag12864b_buffer == NULL) { |
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printk(KERN_ERR CFAG12864B_NAME ": ERROR: " |
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"can't get a free page\n"); |
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ret = -ENOMEM; |
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goto none; |
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} |
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cfag12864b_cache = kmalloc(CFAG12864B_SIZE, |
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GFP_KERNEL); |
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if (cfag12864b_cache == NULL) { |
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printk(KERN_ERR CFAG12864B_NAME ": ERROR: " |
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"can't alloc cache buffer (%i bytes)\n", |
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CFAG12864B_SIZE); |
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ret = -ENOMEM; |
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goto bufferalloced; |
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} |
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cfag12864b_workqueue = create_singlethread_workqueue(CFAG12864B_NAME); |
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if (cfag12864b_workqueue == NULL) |
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goto cachealloced; |
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cfag12864b_clear(); |
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cfag12864b_on(); |
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cfag12864b_inited = 1; |
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return 0; |
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cachealloced: |
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kfree(cfag12864b_cache); |
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bufferalloced: |
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free_page((unsigned long) cfag12864b_buffer); |
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none: |
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return ret; |
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} |
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static void __exit cfag12864b_exit(void) |
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{ |
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cfag12864b_disable(); |
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cfag12864b_off(); |
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destroy_workqueue(cfag12864b_workqueue); |
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kfree(cfag12864b_cache); |
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free_page((unsigned long) cfag12864b_buffer); |
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} |
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module_init(cfag12864b_init); |
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module_exit(cfag12864b_exit); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_AUTHOR("Miguel Ojeda <[email protected]>"); |
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MODULE_DESCRIPTION("cfag12864b LCD driver");
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