| /* |
| ------------------------------------------------------------------------- |
| i2c-adap-ite.c i2c-hw access for the IIC peripheral on the ITE MIPS system |
| ------------------------------------------------------------------------- |
| Hai-Pao Fan, MontaVista Software, Inc. |
| hpfan@mvista.com or source@mvista.com |
| |
| Copyright 2001 MontaVista Software Inc. |
| |
| ---------------------------------------------------------------------------- |
| This file was highly leveraged from i2c-elektor.c, which was created |
| by Simon G. Vogl and Hans Berglund: |
| |
| |
| Copyright (C) 1995-97 Simon G. Vogl |
| 1998-99 Hans Berglund |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| /* ------------------------------------------------------------------------- */ |
| |
| /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even |
| Frodo Looijaard <frodol@dds.nl> */ |
| |
| #include <linux/kernel.h> |
| #include <linux/ioport.h> |
| #include <linux/module.h> |
| #include <linux/delay.h> |
| #include <linux/slab.h> |
| #include <linux/init.h> |
| #include <asm/irq.h> |
| #include <asm/io.h> |
| |
| #include <linux/i2c.h> |
| #include <linux/i2c-algo-ite.h> |
| #include <linux/i2c-adap-ite.h> |
| #include "i2c-ite.h" |
| |
| #define DEFAULT_BASE 0x14014030 |
| #define ITE_IIC_IO_SIZE 0x40 |
| #define DEFAULT_IRQ 0 |
| #define DEFAULT_CLOCK 0x1b0e /* default 16MHz/(27+14) = 400KHz */ |
| #define DEFAULT_OWN 0x55 |
| |
| static int base = 0; |
| static int irq = 0; |
| static int clock = 0; |
| static int own = 0; |
| |
| static int i2c_debug=0; |
| static struct iic_ite gpi; |
| static wait_queue_head_t iic_wait; |
| static int iic_pending; |
| |
| /* ----- global defines ----------------------------------------------- */ |
| #define DEB(x) if (i2c_debug>=1) x |
| #define DEB2(x) if (i2c_debug>=2) x |
| #define DEB3(x) if (i2c_debug>=3) x |
| #define DEBE(x) x /* error messages */ |
| |
| |
| /* ----- local functions ---------------------------------------------- */ |
| |
| static void iic_ite_setiic(void *data, int ctl, short val) |
| { |
| unsigned long j = jiffies + 10; |
| |
| DEB3(printk(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff)); |
| DEB3({while (jiffies < j) schedule();}) |
| outw(val,ctl); |
| } |
| |
| static short iic_ite_getiic(void *data, int ctl) |
| { |
| short val; |
| |
| val = inw(ctl); |
| DEB3(printk("Read 0x%02x from 0x%x\n",(unsigned short)val, ctl&0xff)); |
| return (val); |
| } |
| |
| /* Return our slave address. This is the address |
| * put on the I2C bus when another master on the bus wants to address us |
| * as a slave |
| */ |
| static int iic_ite_getown(void *data) |
| { |
| return (gpi.iic_own); |
| } |
| |
| |
| static int iic_ite_getclock(void *data) |
| { |
| return (gpi.iic_clock); |
| } |
| |
| |
| #if 0 |
| static void iic_ite_sleep(unsigned long timeout) |
| { |
| schedule_timeout( timeout * HZ); |
| } |
| #endif |
| |
| |
| /* Put this process to sleep. We will wake up when the |
| * IIC controller interrupts. |
| */ |
| static void iic_ite_waitforpin(void) { |
| |
| int timeout = 2; |
| |
| /* If interrupts are enabled (which they are), then put the process to |
| * sleep. This process will be awakened by two events -- either the |
| * the IIC peripheral interrupts or the timeout expires. |
| * If interrupts are not enabled then delay for a reasonable amount |
| * of time and return. |
| */ |
| if (gpi.iic_irq > 0) { |
| cli(); |
| if (iic_pending == 0) { |
| interruptible_sleep_on_timeout(&iic_wait, timeout*HZ ); |
| } else |
| iic_pending = 0; |
| sti(); |
| } else { |
| udelay(100); |
| } |
| } |
| |
| |
| static void iic_ite_handler(int this_irq, void *dev_id, struct pt_regs *regs) |
| { |
| |
| iic_pending = 1; |
| |
| DEB2(printk("iic_ite_handler: in interrupt handler\n")); |
| wake_up_interruptible(&iic_wait); |
| } |
| |
| |
| /* Lock the region of memory where I/O registers exist. Request our |
| * interrupt line and register its associated handler. |
| */ |
| static int iic_hw_resrc_init(void) |
| { |
| if (check_region(gpi.iic_base, ITE_IIC_IO_SIZE) < 0 ) { |
| return -ENODEV; |
| } else { |
| request_region(gpi.iic_base, ITE_IIC_IO_SIZE, |
| "i2c (i2c bus adapter)"); |
| } |
| if (gpi.iic_irq > 0) { |
| if (request_irq(gpi.iic_irq, iic_ite_handler, 0, "ITE IIC", 0) < 0) { |
| gpi.iic_irq = 0; |
| } else |
| DEB3(printk("Enabled IIC IRQ %d\n", gpi.iic_irq)); |
| enable_irq(gpi.iic_irq); |
| } |
| return 0; |
| } |
| |
| |
| static void iic_ite_release(void) |
| { |
| if (gpi.iic_irq > 0) { |
| disable_irq(gpi.iic_irq); |
| free_irq(gpi.iic_irq, 0); |
| } |
| release_region(gpi.iic_base , 2); |
| } |
| |
| |
| static int iic_ite_reg(struct i2c_client *client) |
| { |
| return 0; |
| } |
| |
| |
| static int iic_ite_unreg(struct i2c_client *client) |
| { |
| return 0; |
| } |
| |
| |
| static void iic_ite_inc_use(struct i2c_adapter *adap) |
| { |
| #ifdef MODULE |
| MOD_INC_USE_COUNT; |
| #endif |
| } |
| |
| |
| static void iic_ite_dec_use(struct i2c_adapter *adap) |
| { |
| #ifdef MODULE |
| MOD_DEC_USE_COUNT; |
| #endif |
| } |
| |
| |
| /* ------------------------------------------------------------------------ |
| * Encapsulate the above functions in the correct operations structure. |
| * This is only done when more than one hardware adapter is supported. |
| */ |
| static struct i2c_algo_iic_data iic_ite_data = { |
| NULL, |
| iic_ite_setiic, |
| iic_ite_getiic, |
| iic_ite_getown, |
| iic_ite_getclock, |
| iic_ite_waitforpin, |
| 80, 80, 100, /* waits, timeout */ |
| }; |
| |
| static struct i2c_adapter iic_ite_ops = { |
| "ITE IIC adapter", |
| I2C_HW_I_IIC, |
| NULL, |
| &iic_ite_data, |
| iic_ite_inc_use, |
| iic_ite_dec_use, |
| iic_ite_reg, |
| iic_ite_unreg, |
| }; |
| |
| /* Called when the module is loaded. This function starts the |
| * cascade of calls up through the hierarchy of i2c modules (i.e. up to the |
| * algorithm layer and into to the core layer) |
| */ |
| static int __init iic_ite_init(void) |
| { |
| |
| struct iic_ite *piic = &gpi; |
| |
| printk(KERN_INFO "Initialize ITE IIC adapter module\n"); |
| if (base == 0) |
| piic->iic_base = DEFAULT_BASE; |
| else |
| piic->iic_base = base; |
| |
| if (irq == 0) |
| piic->iic_irq = DEFAULT_IRQ; |
| else |
| piic->iic_irq = irq; |
| |
| if (clock == 0) |
| piic->iic_clock = DEFAULT_CLOCK; |
| else |
| piic->iic_clock = clock; |
| |
| if (own == 0) |
| piic->iic_own = DEFAULT_OWN; |
| else |
| piic->iic_own = own; |
| |
| iic_ite_data.data = (void *)piic; |
| if (iic_hw_resrc_init() == 0) { |
| if (i2c_iic_add_bus(&iic_ite_ops) < 0) |
| return -ENODEV; |
| } else { |
| return -ENODEV; |
| } |
| printk(KERN_INFO " found device at %#x irq %d.\n", |
| piic->iic_base, piic->iic_irq); |
| return 0; |
| } |
| |
| |
| static void iic_ite_exit(void) |
| { |
| i2c_iic_del_bus(&iic_ite_ops); |
| iic_ite_release(); |
| } |
| |
| EXPORT_NO_SYMBOLS; |
| |
| /* If modules is NOT defined when this file is compiled, then the MODULE_* |
| * macros will resolve to nothing |
| */ |
| MODULE_AUTHOR("MontaVista Software <www.mvista.com>"); |
| MODULE_DESCRIPTION("I2C-Bus adapter routines for ITE IIC bus adapter"); |
| MODULE_LICENSE("GPL"); |
| |
| MODULE_PARM(base, "i"); |
| MODULE_PARM(irq, "i"); |
| MODULE_PARM(clock, "i"); |
| MODULE_PARM(own, "i"); |
| MODULE_PARM(i2c_debug,"i"); |
| |
| |
| /* Called when module is loaded or when kernel is intialized. |
| * If MODULES is defined when this file is compiled, then this function will |
| * resolve to init_module (the function called when insmod is invoked for a |
| * module). Otherwise, this function is called early in the boot, when the |
| * kernel is intialized. Check out /include/init.h to see how this works. |
| */ |
| module_init(iic_ite_init); |
| |
| /* Resolves to module_cleanup when MODULES is defined. */ |
| module_exit(iic_ite_exit); |