i2c-algo-pca: Extend for future drivers
The separation between algorithm and adapter was unsharp at places. This was
partly hidden by the fact, that the ISA-driver allowed just one instance and
had all private data in static variables. This patch makes neccessary
preparations to add a platform driver on top of the algorithm, while still
supporting ISA. Note: Due to lack of hardware, the ISA-driver could not be
tested except that it builds.
Concerning the core struct i2c_algo_pca_data:
- A private data field was added, all hardware dependant data may go here.
Similar to other algorithms, now a pointer to this data is passed to the
adapter's functions. In order to make as less changes as possible to the
ISA-driver, it leaves the private data empty and still only uses its static
variables.
- A "reset_chip" function pointer was added; such a functionality must come
from the adapter, not the algorithm.
- use a variable "i2c_clock" instead of a function pointer "get_clock",
allowing for write access to a default in case a wrong value was supplied.
In the algorithm-file:
- move "i2c-pca-algo.h" into "linux/i2c-algo-pca.h"
- now using per_instance timeout values (i2c_adap->timeout)
- error messages specify the device, not only the driver name
- restructure initialization to easily support "i2c_add_numbered_adapter"
- drop "retries" and "own" (i2c address) as they were unused
(The state-machine for I2C-communication was not touched.)
In the ISA-driver:
- adapt to new algorithm
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index 93ed325..a119784 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/drivers/i2c/busses/i2c-pca-isa.c
@@ -1,6 +1,7 @@
/*
* i2c-pca-isa.c driver for PCA9564 on ISA boards
* Copyright (C) 2004 Arcom Control Systems
+ * Copyright (C) 2008 Pengutronix
*
* 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
@@ -22,11 +23,9 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/delay.h>
-#include <linux/slab.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
-
#include <linux/isa.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-pca.h>
@@ -34,13 +33,9 @@
#include <asm/io.h>
#include <asm/irq.h>
-#include "../algos/i2c-algo-pca.h"
-
+#define DRIVER "i2c-pca-isa"
#define IO_SIZE 4
-#undef DEBUG_IO
-//#define DEBUG_IO
-
static unsigned long base = 0x330;
static int irq = 10;
@@ -48,22 +43,9 @@
* in the actual clock rate */
static int clock = I2C_PCA_CON_59kHz;
-static int own = 0x55;
-
static wait_queue_head_t pca_wait;
-static int pca_isa_getown(struct i2c_algo_pca_data *adap)
-{
- return (own);
-}
-
-static int pca_isa_getclock(struct i2c_algo_pca_data *adap)
-{
- return (clock);
-}
-
-static void
-pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val)
+static void pca_isa_writebyte(void *pd, int reg, int val)
{
#ifdef DEBUG_IO
static char *names[] = { "T/O", "DAT", "ADR", "CON" };
@@ -72,8 +54,7 @@
outb(val, base+reg);
}
-static int
-pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg)
+static int pca_isa_readbyte(void *pd, int reg)
{
int res = inb(base+reg);
#ifdef DEBUG_IO
@@ -85,31 +66,37 @@
return res;
}
-static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap)
+static int pca_isa_waitforcompletion(void *pd)
{
int ret = 0;
if (irq > -1) {
ret = wait_event_interruptible(pca_wait,
- pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI);
+ pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI);
} else {
- while ((pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
+ while ((pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
udelay(100);
}
return ret;
}
+static void pca_isa_resetchip(void *pd)
+{
+ /* apparently only an external reset will do it. not a lot can be done */
+ printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n");
+}
+
static irqreturn_t pca_handler(int this_irq, void *dev_id) {
wake_up_interruptible(&pca_wait);
return IRQ_HANDLED;
}
static struct i2c_algo_pca_data pca_isa_data = {
- .get_own = pca_isa_getown,
- .get_clock = pca_isa_getclock,
+ /* .data intentionally left NULL, not needed with ISA */
.write_byte = pca_isa_writebyte,
.read_byte = pca_isa_readbyte,
- .wait_for_interrupt = pca_isa_waitforinterrupt,
+ .wait_for_completion = pca_isa_waitforcompletion,
+ .reset_chip = pca_isa_resetchip,
};
static struct i2c_adapter pca_isa_ops = {
@@ -117,6 +104,7 @@
.id = I2C_HW_A_ISA,
.algo_data = &pca_isa_data,
.name = "PCA9564 ISA Adapter",
+ .timeout = 100,
};
static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
@@ -144,6 +132,7 @@
}
}
+ pca_isa_data.i2c_clock = clock;
if (i2c_pca_add_bus(&pca_isa_ops) < 0) {
dev_err(dev, "Failed to add i2c bus\n");
goto out_irq;
@@ -178,7 +167,7 @@
.remove = __devexit_p(pca_isa_remove),
.driver = {
.owner = THIS_MODULE,
- .name = "i2c-pca-isa",
+ .name = DRIVER,
}
};
@@ -204,7 +193,5 @@
module_param(clock, int, 0);
MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet");
-module_param(own, int, 0); /* the driver can't do slave mode, so there's no real point in this */
-
module_init(pca_isa_init);
module_exit(pca_isa_exit);