forked from luck/tmp_suning_uos_patched
a0d9c63d36
i2c-algo-bit: Discard the mdelay data struct member The i2c_algo_bit_data structure has an mdelay member, which is not used by the algorithm code (the code has always been ifdef'd out.) Let's discard it to save some code and memory. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br> Cc: Adrian Bunk <bunk@stusta.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
176 lines
4.8 KiB
C
176 lines
4.8 KiB
C
/* ------------------------------------------------------------------------ *
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* i2c-parport.c I2C bus over parallel port *
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* ------------------------------------------------------------------------ *
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Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org>
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Based on older i2c-velleman.c driver
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Copyright (C) 1995-2000 Simon G. Vogl
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With some changes from:
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Frodo Looijaard <frodol@dds.nl>
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Kyösti Mälkki <kmalkki@cc.hut.fi>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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* ------------------------------------------------------------------------ */
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-bit.h>
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#include <asm/io.h>
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#include "i2c-parport.h"
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#define DEFAULT_BASE 0x378
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static u16 base;
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module_param(base, ushort, 0);
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MODULE_PARM_DESC(base, "Base I/O address");
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/* ----- Low-level parallel port access ----------------------------------- */
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static inline void port_write(unsigned char p, unsigned char d)
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{
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outb(d, base+p);
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}
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static inline unsigned char port_read(unsigned char p)
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{
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return inb(base+p);
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}
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/* ----- Unified line operation functions --------------------------------- */
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static inline void line_set(int state, const struct lineop *op)
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{
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u8 oldval = port_read(op->port);
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/* Touch only the bit(s) needed */
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if ((op->inverted && !state) || (!op->inverted && state))
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port_write(op->port, oldval | op->val);
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else
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port_write(op->port, oldval & ~op->val);
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}
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static inline int line_get(const struct lineop *op)
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{
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u8 oldval = port_read(op->port);
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return ((op->inverted && (oldval & op->val) != op->val)
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|| (!op->inverted && (oldval & op->val) == op->val));
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}
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/* ----- I2C algorithm call-back functions and structures ----------------- */
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static void parport_setscl(void *data, int state)
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{
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line_set(state, &adapter_parm[type].setscl);
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}
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static void parport_setsda(void *data, int state)
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{
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line_set(state, &adapter_parm[type].setsda);
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}
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static int parport_getscl(void *data)
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{
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return line_get(&adapter_parm[type].getscl);
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}
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static int parport_getsda(void *data)
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{
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return line_get(&adapter_parm[type].getsda);
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}
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/* Encapsulate the functions above in the correct structure
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Note that getscl will be set to NULL by the attaching code for adapters
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that cannot read SCL back */
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static struct i2c_algo_bit_data parport_algo_data = {
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.setsda = parport_setsda,
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.setscl = parport_setscl,
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.getsda = parport_getsda,
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.getscl = parport_getscl,
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.udelay = 50,
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.timeout = HZ,
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};
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/* ----- I2c structure ---------------------------------------------------- */
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static struct i2c_adapter parport_adapter = {
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.owner = THIS_MODULE,
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.class = I2C_CLASS_HWMON,
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.id = I2C_HW_B_LP,
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.algo_data = &parport_algo_data,
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.name = "Parallel port adapter (light)",
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};
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/* ----- Module loading, unloading and information ------------------------ */
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static int __init i2c_parport_init(void)
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{
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if (type < 0) {
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printk(KERN_WARNING "i2c-parport: adapter type unspecified\n");
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return -ENODEV;
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}
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if (type >= ARRAY_SIZE(adapter_parm)) {
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printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type);
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return -ENODEV;
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}
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if (base == 0) {
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printk(KERN_INFO "i2c-parport: using default base 0x%x\n", DEFAULT_BASE);
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base = DEFAULT_BASE;
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}
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if (!request_region(base, 3, "i2c-parport"))
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return -ENODEV;
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if (!adapter_parm[type].getscl.val)
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parport_algo_data.getscl = NULL;
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/* Reset hardware to a sane state (SCL and SDA high) */
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parport_setsda(NULL, 1);
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parport_setscl(NULL, 1);
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/* Other init if needed (power on...) */
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if (adapter_parm[type].init.val)
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line_set(1, &adapter_parm[type].init);
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if (i2c_bit_add_bus(&parport_adapter) < 0) {
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printk(KERN_ERR "i2c-parport: Unable to register with I2C\n");
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release_region(base, 3);
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return -ENODEV;
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}
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return 0;
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}
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static void __exit i2c_parport_exit(void)
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{
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/* Un-init if needed (power off...) */
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if (adapter_parm[type].init.val)
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line_set(0, &adapter_parm[type].init);
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i2c_bit_del_bus(&parport_adapter);
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release_region(base, 3);
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}
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MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
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MODULE_DESCRIPTION("I2C bus over parallel port (light)");
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MODULE_LICENSE("GPL");
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module_init(i2c_parport_init);
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module_exit(i2c_parport_exit);
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