cregit-Linux how code gets into the kernel

Release 4.14 drivers/auxdisplay/cfag12864b.c

/*
 *    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 (hertz)");


unsigned int cfag12864b_getrate(void) { return cfag12864b_rate; }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis11100.00%1100.00%
Total11100.00%1100.00%

/* * cfag12864b Commands * * E = Enable signal * Every time 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); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis13100.00%1100.00%
Total13100.00%1100.00%


static void cfag12864b_setbit(unsigned char state, unsigned char n) { if (state) cfag12864b_state |= bit(n); else cfag12864b_state &= ~bit(n); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis34100.00%1100.00%
Total34100.00%1100.00%


static void cfag12864b_e(unsigned char state) { cfag12864b_setbit(state, CFAG12864B_BIT_E); cfag12864b_set(); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis20100.00%1100.00%
Total20100.00%1100.00%


static void cfag12864b_cs1(unsigned char state) { cfag12864b_setbit(state, CFAG12864B_BIT_CS1); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis17100.00%1100.00%
Total17100.00%1100.00%


static void cfag12864b_cs2(unsigned char state) { cfag12864b_setbit(state, CFAG12864B_BIT_CS2); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis17100.00%1100.00%
Total17100.00%1100.00%


static void cfag12864b_di(unsigned char state) { cfag12864b_setbit(state, CFAG12864B_BIT_DI); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis17100.00%1100.00%
Total17100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis44100.00%1100.00%
Total44100.00%1100.00%


static void cfag12864b_controller(unsigned char which) { if (which == 0) cfag12864b_setcontrollers(1, 0); else if (which == 1) cfag12864b_setcontrollers(0, 1); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis37100.00%1100.00%
Total37100.00%1100.00%


static void cfag12864b_displaystate(unsigned char state) { cfag12864b_di(0); cfag12864b_e(1); ks0108_displaystate(state); cfag12864b_e(0); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis30100.00%1100.00%
Total30100.00%1100.00%


static void cfag12864b_address(unsigned char address) { cfag12864b_di(0); cfag12864b_e(1); ks0108_address(address); cfag12864b_e(0); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis30100.00%1100.00%
Total30100.00%1100.00%


static void cfag12864b_page(unsigned char page) { cfag12864b_di(0); cfag12864b_e(1); ks0108_page(page); cfag12864b_e(0); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis30100.00%1100.00%
Total30100.00%1100.00%


static void cfag12864b_startline(unsigned char startline) { cfag12864b_di(0); cfag12864b_e(1); ks0108_startline(startline); cfag12864b_e(0); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis30100.00%1100.00%
Total30100.00%1100.00%


static void cfag12864b_writebyte(unsigned char byte) { cfag12864b_di(1); cfag12864b_e(1); ks0108_writedata(byte); cfag12864b_e(0); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis30100.00%1100.00%
Total30100.00%1100.00%


static void cfag12864b_nop(void) { cfag12864b_startline(0); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis13100.00%1100.00%
Total13100.00%1100.00%

/* * cfag12864b Internal Commands */
static void cfag12864b_on(void) { cfag12864b_setcontrollers(1, 1); cfag12864b_displaystate(1); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis20100.00%1100.00%
Total20100.00%1100.00%


static void cfag12864b_off(void) { cfag12864b_setcontrollers(1, 1); cfag12864b_displaystate(0); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis20100.00%1100.00%
Total20100.00%1100.00%


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); } }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis64100.00%1100.00%
Total64100.00%1100.00%

/* * 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); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis20100.00%1100.00%
Total20100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis50100.00%1100.00%
Total50100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis40100.00%1100.00%
Total40100.00%1100.00%


unsigned char cfag12864b_isenabled(void) { return cfag12864b_updating; }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis11100.00%1100.00%
Total11100.00%1100.00%


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(); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis186100.00%1100.00%
Total186100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis11100.00%1100.00%
Total11100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis16598.21%375.00%
Akinobu Mita31.79%125.00%
Total168100.00%4100.00%


static void __exit cfag12864b_exit(void) { cfag12864b_disable(); cfag12864b_off(); destroy_workqueue(cfag12864b_workqueue); kfree(cfag12864b_cache); free_page((unsigned long) cfag12864b_buffer); }

Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis34100.00%1100.00%
Total34100.00%1100.00%

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");

Overall Contributors

PersonTokensPropCommitsCommitProp
Miguel Ojeda Sandonis120199.17%342.86%
Tejun Heo30.25%114.29%
Akinobu Mita30.25%114.29%
Miguel Ojeda20.17%114.29%
Lucas De Marchi20.17%114.29%
Total1211100.00%7100.00%
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