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>

1 files changed, 19 insertions, 32 deletions

diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index 93ed3251893d..a119784bae10 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 @@ static int irq 	  = 10;
  * 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 @@ pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val)
         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 @@ pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg)
         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 @@ static struct i2c_adapter pca_isa_ops = {
         .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 @@ static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
                 }
         }
 
+        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 @@ static struct isa_driver pca_isa_driver = {
         .remove         = __devexit_p(pca_isa_remove),
         .driver = {
                 .owner  = THIS_MODULE,
-                .name   = "i2c-pca-isa",
+                .name   = DRIVER,
         }
 };
 
@@ -204,7 +193,5 @@ MODULE_PARM_DESC(irq, "IRQ");
 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);