2 -------------------------------------------------------------------------
3 i2c-adap-ite.c i2c-hw access for the IIC peripheral on the ITE MIPS system
4 -------------------------------------------------------------------------
5 Hai-Pao Fan, MontaVista Software, Inc.
6 hpfan@mvista.com or source@mvista.com
8 Copyright 2001 MontaVista Software Inc.
10 ----------------------------------------------------------------------------
11 This file was highly leveraged from i2c-elektor.c, which was created
12 by Simon G. Vogl and Hans Berglund:
15 Copyright (C) 1995-97 Simon G. Vogl
18 This program is free software; you can redistribute it and/or modify
19 it under the terms of the GNU General Public License as published by
20 the Free Software Foundation; either version 2 of the License, or
21 (at your option) any later version.
23 This program is distributed in the hope that it will be useful,
24 but WITHOUT ANY WARRANTY; without even the implied warranty of
25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26 GNU General Public License for more details.
28 You should have received a copy of the GNU General Public License
29 along with this program; if not, write to the Free Software
30 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
31 /* ------------------------------------------------------------------------- */
33 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
34 Frodo Looijaard <frodol@dds.nl> */
36 #include <linux/config.h>
37 #include <linux/kernel.h>
38 #include <linux/ioport.h>
39 #include <linux/module.h>
40 #include <linux/delay.h>
41 #include <linux/slab.h>
42 #include <linux/init.h>
43 #include <linux/wait.h>
47 #include <linux/i2c.h>
48 #include <linux/i2c-algo-ite.h>
49 #include <linux/i2c-adap-ite.h>
50 #include "../i2c-ite.h"
52 #define DEFAULT_BASE 0x14014030
53 #define ITE_IIC_IO_SIZE 0x40
55 #define DEFAULT_CLOCK 0x1b0e /* default 16MHz/(27+14) = 400KHz */
56 #define DEFAULT_OWN 0x55
63 static struct iic_ite gpi;
64 static wait_queue_head_t iic_wait;
65 static int iic_pending;
66 static spinlock_t lock;
68 /* ----- local functions ---------------------------------------------- */
70 static void iic_ite_setiic(void *data, int ctl, short val)
72 unsigned long j = jiffies + 10;
74 pr_debug(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff);
76 while (time_before(jiffies, j))
82 static short iic_ite_getiic(void *data, int ctl)
87 pr_debug("Read 0x%02x from 0x%x\n",(unsigned short)val, ctl&0xff);
91 /* Return our slave address. This is the address
92 * put on the I2C bus when another master on the bus wants to address us
95 static int iic_ite_getown(void *data)
101 static int iic_ite_getclock(void *data)
103 return (gpi.iic_clock);
107 /* Put this process to sleep. We will wake up when the
108 * IIC controller interrupts.
110 static void iic_ite_waitforpin(void) {
115 /* If interrupts are enabled (which they are), then put the process to
116 * sleep. This process will be awakened by two events -- either the
117 * the IIC peripheral interrupts or the timeout expires.
118 * If interrupts are not enabled then delay for a reasonable amount
119 * of time and return.
121 if (gpi.iic_irq > 0) {
122 spin_lock_irqsave(&lock, flags);
123 if (iic_pending == 0) {
124 spin_unlock_irqrestore(&lock, flags);
125 prepare_to_wait(&iic_wait, &wait, TASK_INTERRUPTIBLE);
126 if (schedule_timeout(timeout*HZ)) {
127 spin_lock_irqsave(&lock, flags);
128 if (iic_pending == 1) {
131 spin_unlock_irqrestore(&lock, flags);
133 finish_wait(&iic_wait, &wait);
136 spin_unlock_irqrestore(&lock, flags);
144 static irqreturn_t iic_ite_handler(int this_irq, void *dev_id,
145 struct pt_regs *regs)
151 wake_up_interruptible(&iic_wait);
157 /* Lock the region of memory where I/O registers exist. Request our
158 * interrupt line and register its associated handler.
160 static int iic_hw_resrc_init(void)
162 if (!request_region(gpi.iic_base, ITE_IIC_IO_SIZE, "i2c"))
165 if (gpi.iic_irq <= 0)
168 if (request_irq(gpi.iic_irq, iic_ite_handler, 0, "ITE IIC", 0) < 0)
171 enable_irq(gpi.iic_irq);
177 static void iic_ite_release(void)
179 if (gpi.iic_irq > 0) {
180 disable_irq(gpi.iic_irq);
181 free_irq(gpi.iic_irq, 0);
183 release_region(gpi.iic_base , 2);
186 /* ------------------------------------------------------------------------
187 * Encapsulate the above functions in the correct operations structure.
188 * This is only done when more than one hardware adapter is supported.
190 static struct i2c_algo_iic_data iic_ite_data = {
197 80, 80, 100, /* waits, timeout */
200 static struct i2c_adapter iic_ite_ops = {
201 .owner = THIS_MODULE,
203 .algo_data = &iic_ite_data,
205 .name = "ITE IIC adapter",
209 /* Called when the module is loaded. This function starts the
210 * cascade of calls up through the hierarchy of i2c modules (i.e. up to the
211 * algorithm layer and into to the core layer)
213 static int __init iic_ite_init(void)
216 struct iic_ite *piic = &gpi;
218 printk(KERN_INFO "Initialize ITE IIC adapter module\n");
220 piic->iic_base = DEFAULT_BASE;
222 piic->iic_base = base;
225 piic->iic_irq = DEFAULT_IRQ;
230 piic->iic_clock = DEFAULT_CLOCK;
232 piic->iic_clock = clock;
235 piic->iic_own = DEFAULT_OWN;
239 iic_ite_data.data = (void *)piic;
240 init_waitqueue_head(&iic_wait);
241 spin_lock_init(&lock);
242 if (iic_hw_resrc_init() == 0) {
243 if (i2c_iic_add_bus(&iic_ite_ops) < 0)
248 printk(KERN_INFO " found device at %#x irq %d.\n",
249 piic->iic_base, piic->iic_irq);
254 static void iic_ite_exit(void)
256 i2c_iic_del_bus(&iic_ite_ops);
260 /* If modules is NOT defined when this file is compiled, then the MODULE_*
261 * macros will resolve to nothing
263 MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
264 MODULE_DESCRIPTION("I2C-Bus adapter routines for ITE IIC bus adapter");
265 MODULE_LICENSE("GPL");
267 module_param(base, int, 0);
268 module_param(irq, int, 0);
269 module_param(clock, int, 0);
270 module_param(own, int, 0);
273 /* Called when module is loaded or when kernel is initialized.
274 * If MODULES is defined when this file is compiled, then this function will
275 * resolve to init_module (the function called when insmod is invoked for a
276 * module). Otherwise, this function is called early in the boot, when the
277 * kernel is intialized. Check out /include/init.h to see how this works.
279 module_init(iic_ite_init);
281 /* Resolves to module_cleanup when MODULES is defined. */
282 module_exit(iic_ite_exit);