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
- updated tests to variable "irq" to the convention that 0 is NO_IRQ
Signed-off-by: Wolfram Sang <[EMAIL PROTECTED]>
---
drivers/i2c/algos/i2c-algo-pca.c | 87 +++++++++++++++++++--------------------
drivers/i2c/algos/i2c-algo-pca.h | 26 -----------
drivers/i2c/busses/i2c-pca-isa.c | 59 ++++++++++----------------
include/linux/i2c-algo-pca.h | 37 ++++++++++++++--
4 files changed, 98 insertions(+), 111 deletions(-)
Index: linux-playground/include/linux/i2c-algo-pca.h
===================================================================
--- linux-playground.orig/include/linux/i2c-algo-pca.h 2008-02-06
20:15:37.000000000 +0100
+++ linux-playground/include/linux/i2c-algo-pca.h 2008-02-06
20:15:48.000000000 +0100
@@ -1,14 +1,41 @@
#ifndef _LINUX_I2C_ALGO_PCA_H
#define _LINUX_I2C_ALGO_PCA_H
+/* Clock speeds for the bus */
+#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
+
+/* PCA9564 registers */
+#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) */
+
struct i2c_algo_pca_data {
- int (*get_own) (struct i2c_algo_pca_data *adap); /*
Obtain own address */
- int (*get_clock) (struct i2c_algo_pca_data *adap);
- void (*write_byte) (struct i2c_algo_pca_data *adap, int
reg, int val);
- int (*read_byte) (struct i2c_algo_pca_data *adap, int
reg);
- int (*wait_for_interrupt) (struct i2c_algo_pca_data *adap);
+ void *data; /* private low level data */
+ void (*write_byte) (void *data, int reg, int val);
+ int (*read_byte) (void *data, int reg);
+ int (*wait_for_completion) (void *data);
+ void (*reset_chip) (void *data);
+ /* i2c_clock values are defined in linux/i2c-algo-pca.h */
+ unsigned int i2c_clock;
};
int i2c_pca_add_bus(struct i2c_adapter *);
+int i2c_pca_add_numbered_bus(struct i2c_adapter *);
#endif /* _LINUX_I2C_ALGO_PCA_H */
Index: linux-playground/drivers/i2c/algos/i2c-algo-pca.h
===================================================================
--- linux-playground.orig/drivers/i2c/algos/i2c-algo-pca.h 2008-02-06
20:15:37.000000000 +0100
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -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 */
Index: linux-playground/drivers/i2c/algos/i2c-algo-pca.c
===================================================================
--- linux-playground.orig/drivers/i2c/algos/i2c-algo-pca.c 2008-02-06
20:15:41.000000000 +0100
+++ linux-playground/drivers/i2c/algos/i2c-algo-pca.c 2008-02-06
20:15:48.000000000 +0100
@@ -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 @@
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 @@
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 @@
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 +325,64 @@
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) {
+ dev_warn(&adap->dev, "Invalid I2C clock speed selected. Trying
default.\n");
+ 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 <[EMAIL PROTECTED]>");
+MODULE_AUTHOR("Ian Campbell <[EMAIL PROTECTED]>, "
+ "Wolfram Sang <[EMAIL PROTECTED]>");
MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
MODULE_LICENSE("GPL");
Index: linux-playground/drivers/i2c/busses/i2c-pca-isa.c
===================================================================
--- linux-playground.orig/drivers/i2c/busses/i2c-pca-isa.c 2008-02-06
20:15:41.000000000 +0100
+++ linux-playground/drivers/i2c/busses/i2c-pca-isa.c 2008-02-06
20:15:48.000000000 +0100
@@ -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) {
+ if (irq) {
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)
@@ -130,13 +118,14 @@
goto out;
}
- if (irq > -1) {
+ if (irq) {
if (request_irq(irq, pca_handler, 0, "i2c-pca-isa",
&pca_isa_ops) < 0) {
dev_err(dev, "Request irq%d failed\n", irq);
goto out_region;
}
}
+ 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;
@@ -145,7 +134,7 @@
return 0;
out_irq:
- if (irq > -1)
+ if (irq)
free_irq(irq, &pca_isa_ops);
out_region:
release_region(base, IO_SIZE);
@@ -157,7 +146,7 @@
{
i2c_del_adapter(&pca_isa_ops);
- if (irq > 0) {
+ if (irq) {
disable_irq(irq);
free_irq(irq, &pca_isa_ops);
}
@@ -171,7 +160,7 @@
.remove = __devexit_p(pca_isa_remove),
.driver = {
.owner = THIS_MODULE,
- .name = "i2c-pca-isa",
+ .name = DRIVER,
}
};
@@ -197,7 +186,5 @@
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);
--
Dipl.-Ing. Wolfram Sang | http://www.pengutronix.de
Pengutronix - Linux Solutions for Science and Industry
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