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>
46 #include <linux/i2c.h>
47 #include <linux/i2c-algo-ite.h>
48 #include <linux/i2c-adap-ite.h>
49 #include "../i2c-ite.h"
51 #define DEFAULT_BASE 0x14014030
52 #define ITE_IIC_IO_SIZE 0x40
54 #define DEFAULT_CLOCK 0x1b0e /* default 16MHz/(27+14) = 400KHz */
55 #define DEFAULT_OWN 0x55
62 static struct iic_ite gpi;
63 static wait_queue_head_t iic_wait;
64 static int iic_pending;
66 /* ----- local functions ---------------------------------------------- */
68 static void iic_ite_setiic(void *data, int ctl, short val)
70 unsigned long j = jiffies + 10;
72 pr_debug(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff);
74 while (time_before(jiffies, j))
80 static short iic_ite_getiic(void *data, int ctl)
85 pr_debug("Read 0x%02x from 0x%x\n",(unsigned short)val, ctl&0xff);
89 /* Return our slave address. This is the address
90 * put on the I2C bus when another master on the bus wants to address us
93 static int iic_ite_getown(void *data)
99 static int iic_ite_getclock(void *data)
101 return (gpi.iic_clock);
106 static void iic_ite_sleep(unsigned long timeout)
108 schedule_timeout( timeout * HZ);
113 /* Put this process to sleep. We will wake up when the
114 * IIC controller interrupts.
116 static void iic_ite_waitforpin(void) {
120 /* If interrupts are enabled (which they are), then put the process to
121 * sleep. This process will be awakened by two events -- either the
122 * the IIC peripheral interrupts or the timeout expires.
123 * If interrupts are not enabled then delay for a reasonable amount
124 * of time and return.
126 if (gpi.iic_irq > 0) {
128 if (iic_pending == 0) {
129 interruptible_sleep_on_timeout(&iic_wait, timeout*HZ );
139 static void iic_ite_handler(int this_irq, void *dev_id, struct pt_regs *regs)
144 wake_up_interruptible(&iic_wait);
148 /* Lock the region of memory where I/O registers exist. Request our
149 * interrupt line and register its associated handler.
151 static int iic_hw_resrc_init(void)
153 if (!request_region(gpi.iic_base, ITE_IIC_IO_SIZE, "i2c"))
156 if (gpi.iic_irq <= 0)
159 if (request_irq(gpi.iic_irq, iic_ite_handler, 0, "ITE IIC", 0) < 0)
162 enable_irq(gpi.iic_irq);
168 static void iic_ite_release(void)
170 if (gpi.iic_irq > 0) {
171 disable_irq(gpi.iic_irq);
172 free_irq(gpi.iic_irq, 0);
174 release_region(gpi.iic_base , 2);
177 /* ------------------------------------------------------------------------
178 * Encapsulate the above functions in the correct operations structure.
179 * This is only done when more than one hardware adapter is supported.
181 static struct i2c_algo_iic_data iic_ite_data = {
188 80, 80, 100, /* waits, timeout */
191 static struct i2c_adapter iic_ite_ops = {
192 .owner = THIS_MODULE,
194 .algo_data = &iic_ite_data,
196 .name = "ITE IIC adapter",
200 /* Called when the module is loaded. This function starts the
201 * cascade of calls up through the hierarchy of i2c modules (i.e. up to the
202 * algorithm layer and into to the core layer)
204 static int __init iic_ite_init(void)
207 struct iic_ite *piic = &gpi;
209 printk(KERN_INFO "Initialize ITE IIC adapter module\n");
211 piic->iic_base = DEFAULT_BASE;
213 piic->iic_base = base;
216 piic->iic_irq = DEFAULT_IRQ;
221 piic->iic_clock = DEFAULT_CLOCK;
223 piic->iic_clock = clock;
226 piic->iic_own = DEFAULT_OWN;
230 iic_ite_data.data = (void *)piic;
231 init_waitqueue_head(&iic_wait);
232 if (iic_hw_resrc_init() == 0) {
233 if (i2c_iic_add_bus(&iic_ite_ops) < 0)
238 printk(KERN_INFO " found device at %#x irq %d.\n",
239 piic->iic_base, piic->iic_irq);
244 static void iic_ite_exit(void)
246 i2c_iic_del_bus(&iic_ite_ops);
250 /* If modules is NOT defined when this file is compiled, then the MODULE_*
251 * macros will resolve to nothing
253 MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
254 MODULE_DESCRIPTION("I2C-Bus adapter routines for ITE IIC bus adapter");
255 MODULE_LICENSE("GPL");
257 MODULE_PARM(base, "i");
258 MODULE_PARM(irq, "i");
259 MODULE_PARM(clock, "i");
260 MODULE_PARM(own, "i");
263 /* Called when module is loaded or when kernel is initialized.
264 * If MODULES is defined when this file is compiled, then this function will
265 * resolve to init_module (the function called when insmod is invoked for a
266 * module). Otherwise, this function is called early in the boot, when the
267 * kernel is intialized. Check out /include/init.h to see how this works.
269 module_init(iic_ite_init);
271 /* Resolves to module_cleanup when MODULES is defined. */
272 module_exit(iic_ite_exit);