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>

2 files changed, 44 insertions, 70 deletions

diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index ebec91d71e1e..e954a20b97a6 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -1,6 +1,7 @@
 /*
  *  i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
  *    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
@@ -21,14 +22,10 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/delay.h>
-#include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-pca.h>
-#include "i2c-algo-pca.h"
-
-#define DRIVER "i2c-algo-pca"
 
 #define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
 #define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
@@ -36,15 +33,15 @@
 
 static int i2c_debug;
 
-#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)
-#define pca_inw(adap, reg) adap->read_byte(adap, reg)
+#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
+#define pca_inw(adap, reg) adap->read_byte(adap->data, reg)
 
 #define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
-#define pca_clock(adap) adap->get_clock(adap)
-#define pca_own(adap) adap->get_own(adap)
+#define pca_clock(adap) adap->i2c_clock
 #define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
 #define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
-#define pca_wait(adap) adap->wait_for_interrupt(adap)
+#define pca_wait(adap) adap->wait_for_completion(adap->data)
+#define pca_reset(adap) adap->reset_chip(adap->data)
 
 /*
  * Generate a start condition on the i2c bus.
@@ -168,15 +165,6 @@ static void pca_rx_ack(struct i2c_algo_pca_data *adap,
         pca_wait(adap);
 }
 
-/*
- * Reset the i2c bus / SIO
- */
-static void pca_reset(struct i2c_algo_pca_data *adap)
-{
-        /* apparently only an external reset will do it. not a lot can be done */
-        printk(KERN_ERR DRIVER ": Haven't figured out how to do a reset yet\n");
-}
-
 static int pca_xfer(struct i2c_adapter *i2c_adap,
                     struct i2c_msg *msgs,
                     int num)
@@ -187,7 +175,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
         int numbytes = 0;
         int state;
         int ret;
-        int timeout = 100;
+        int timeout = i2c_adap->timeout;
 
         while ((state = pca_status(adap)) != 0xf8 && timeout--) {
                 msleep(10);
@@ -317,7 +305,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
                         pca_reset(adap);
                         goto out;
                 default:
-                        printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
+                        dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
                         break;
                 }
 
@@ -337,53 +325,65 @@ static u32 pca_func(struct i2c_adapter *adap)
         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }
 
-static int pca_init(struct i2c_algo_pca_data *adap)
+static const struct i2c_algorithm pca_algo = {
+        .master_xfer    = pca_xfer,
+        .functionality  = pca_func,
+};
+
+static int pca_init(struct i2c_adapter *adap)
 {
         static int freqs[] = {330,288,217,146,88,59,44,36};
-        int own, clock;
+        int clock;
+        struct i2c_algo_pca_data *pca_data = adap->algo_data;
+
+        if (pca_data->i2c_clock > 7) {
+                printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",
+                        adap->name);
+                pca_data->i2c_clock = I2C_PCA_CON_59kHz;
+        }
+
+        adap->algo = &pca_algo;
 
-        own = pca_own(adap);
-        clock = pca_clock(adap);
-        DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
-        DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);
+        pca_reset(pca_data);
 
-        pca_outw(adap, I2C_PCA_ADR, own << 1);
+        clock = pca_clock(pca_data);
+        DEB1(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name, freqs[clock]);
 
-        pca_set_con(adap, I2C_PCA_CON_ENSIO | clock);
+        pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
         udelay(500); /* 500 us for oscilator to stabilise */
 
         return 0;
 }
 
-static const struct i2c_algorithm pca_algo = {
-        .master_xfer    = pca_xfer,
-        .functionality  = pca_func,
-};
-
 /*
  * registering functions to load algorithms at runtime
  */
 int i2c_pca_add_bus(struct i2c_adapter *adap)
 {
-        struct i2c_algo_pca_data *pca_adap = adap->algo_data;
         int rval;
 
-        /* register new adapter to i2c module... */
-        adap->algo = &pca_algo;
+        rval = pca_init(adap);
+        if (rval)
+                return rval;
 
-        adap->timeout = 100;            /* default values, should       */
-        adap->retries = 3;              /* be replaced by defines       */
+        return i2c_add_adapter(adap);
+}
+EXPORT_SYMBOL(i2c_pca_add_bus);
 
-        if ((rval = pca_init(pca_adap)))
-                return rval;
+int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
+{
+        int rval;
 
-        rval = i2c_add_adapter(adap);
+        rval = pca_init(adap);
+        if (rval)
+                return rval;
 
-        return rval;
+        return i2c_add_numbered_adapter(adap);
 }
-EXPORT_SYMBOL(i2c_pca_add_bus);
+EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
 
-MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
+MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
+        "Wolfram Sang <w.sang@pengutronix.de>");
 MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
 MODULE_LICENSE("GPL");
 
diff --git a/drivers/i2c/algos/i2c-algo-pca.h b/drivers/i2c/algos/i2c-algo-pca.h
deleted file mode 100644
index 2fee07e05211..000000000000
--- a/drivers/i2c/algos/i2c-algo-pca.h
+++ /dev/null
@@ -1,26 +0,0 @@
-#ifndef I2C_PCA9564_H
-#define I2C_PCA9564_H 1
-
-#define I2C_PCA_STA             0x00 /* STATUS  Read Only  */
-#define I2C_PCA_TO              0x00 /* TIMEOUT Write Only */
-#define I2C_PCA_DAT             0x01 /* DATA    Read/Write */
-#define I2C_PCA_ADR             0x02 /* OWN ADR Read/Write */
-#define I2C_PCA_CON             0x03 /* CONTROL Read/Write */
-
-#define I2C_PCA_CON_AA          0x80 /* Assert Acknowledge */
-#define I2C_PCA_CON_ENSIO       0x40 /* Enable */
-#define I2C_PCA_CON_STA         0x20 /* Start */
-#define I2C_PCA_CON_STO         0x10 /* Stop */
-#define I2C_PCA_CON_SI          0x08 /* Serial Interrupt */
-#define I2C_PCA_CON_CR          0x07 /* Clock Rate (MASK) */
-
-#define I2C_PCA_CON_330kHz      0x00
-#define I2C_PCA_CON_288kHz      0x01
-#define I2C_PCA_CON_217kHz      0x02
-#define I2C_PCA_CON_146kHz      0x03
-#define I2C_PCA_CON_88kHz       0x04
-#define I2C_PCA_CON_59kHz       0x05
-#define I2C_PCA_CON_44kHz       0x06
-#define I2C_PCA_CON_36kHz       0x07
-
-#endif /* I2C_PCA9564_H */