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Diffstat (limited to 'drivers/i2c/busses/i2c-ite.c')
-rw-r--r--drivers/i2c/busses/i2c-ite.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-ite.c b/drivers/i2c/busses/i2c-ite.c
new file mode 100644
index 00000000000..702e3def1b8
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ite.c
@@ -0,0 +1,282 @@
+/*
+ -------------------------------------------------------------------------
+ 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/config.h>
+#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 <linux/wait.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;
+static int irq;
+static int clock;
+static int own;
+
+static struct iic_ite gpi;
+static wait_queue_head_t iic_wait;
+static int iic_pending;
+static spinlock_t lock;
+
+/* ----- local functions ---------------------------------------------- */
+
+static void iic_ite_setiic(void *data, int ctl, short val)
+{
+ unsigned long j = jiffies + 10;
+
+ pr_debug(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff);
+#ifdef DEBUG
+ while (time_before(jiffies, j))
+ schedule();
+#endif
+ outw(val,ctl);
+}
+
+static short iic_ite_getiic(void *data, int ctl)
+{
+ short val;
+
+ val = inw(ctl);
+ pr_debug("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);
+}
+
+
+/* Put this process to sleep. We will wake up when the
+ * IIC controller interrupts.
+ */
+static void iic_ite_waitforpin(void) {
+ DEFINE_WAIT(wait);
+ int timeout = 2;
+ long flags;
+
+ /* 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) {
+ spin_lock_irqsave(&lock, flags);
+ if (iic_pending == 0) {
+ spin_unlock_irqrestore(&lock, flags);
+ prepare_to_wait(&iic_wait, &wait, TASK_INTERRUPTIBLE);
+ if (schedule_timeout(timeout*HZ)) {
+ spin_lock_irqsave(&lock, flags);
+ if (iic_pending == 1) {
+ iic_pending = 0;
+ }
+ spin_unlock_irqrestore(&lock, flags);
+ }
+ finish_wait(&iic_wait, &wait);
+ } else {
+ iic_pending = 0;
+ spin_unlock_irqrestore(&lock, flags);
+ }
+ } else {
+ udelay(100);
+ }
+}
+
+
+static irqreturn_t iic_ite_handler(int this_irq, void *dev_id,
+ struct pt_regs *regs)
+{
+ spin_lock(&lock);
+ iic_pending = 1;
+ spin_unlock(&lock);
+
+ wake_up_interruptible(&iic_wait);
+
+ return IRQ_HANDLED;
+}
+
+
+/* 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 (!request_region(gpi.iic_base, ITE_IIC_IO_SIZE, "i2c"))
+ return -ENODEV;
+
+ if (gpi.iic_irq <= 0)
+ return 0;
+
+ if (request_irq(gpi.iic_irq, iic_ite_handler, 0, "ITE IIC", 0) < 0)
+ gpi.iic_irq = 0;
+ else
+ 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);
+}
+
+/* ------------------------------------------------------------------------
+ * 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 = {
+ .owner = THIS_MODULE,
+ .id = I2C_HW_I_IIC,
+ .algo_data = &iic_ite_data,
+ .dev = {
+ .name = "ITE IIC adapter",
+ },
+};
+
+/* 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;
+ init_waitqueue_head(&iic_wait);
+ spin_lock_init(&lock);
+ 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();
+}
+
+/* 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_param(base, int, 0);
+module_param(irq, int, 0);
+module_param(clock, int, 0);
+module_param(own, int, 0);
+
+
+/* Called when module is loaded or when kernel is initialized.
+ * 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);