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Commit c01b0831 authored by Wolfram Sang's avatar Wolfram Sang Committed by Jean Delvare
Browse files

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: default avatarWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 3d438291

drivers/i2c/algos/i2c-algo-pca.c

+44 −44
Original line number Original line Diff line number Diff line 
/*

/*

 *  i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters

 *  i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters

 *    Copyright (C) 2004 Arcom Control Systems

 *    Copyright (C) 2004 Arcom Control Systems

 *    Copyright (C) 2008 Pengutronix

 *

 *

 *  This program is free software; you can redistribute it and/or modify

 *  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

 *  it under the terms of the GNU General Public License as published by
@@ -21,14 +22,10 @@ 
#include <linux/module.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/moduleparam.h>

#include <linux/delay.h>

#include <linux/delay.h>

#include <linux/slab.h>

#include <linux/init.h>

#include <linux/init.h>

#include <linux/errno.h>

#include <linux/errno.h>

#include <linux/i2c.h>

#include <linux/i2c.h>

#include <linux/i2c-algo-pca.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 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)

#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
@@ -36,15 +33,15 @@ 




static int i2c_debug;

static int i2c_debug;





#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)

#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)

#define pca_inw(adap, reg) adap->read_byte(adap, reg)

#define pca_inw(adap, reg) adap->read_byte(adap->data, reg)





#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)

#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)

#define pca_clock(adap) adap->get_clock(adap)

#define pca_clock(adap) adap->i2c_clock

#define pca_own(adap) adap->get_own(adap)

#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)

#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_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.

 * 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);

	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,

static int pca_xfer(struct i2c_adapter *i2c_adap,

                    struct i2c_msg *msgs,

                    struct i2c_msg *msgs,

                    int num)

                    int num)
@@ -187,7 +175,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap, 
	int numbytes = 0;

	int numbytes = 0;

	int state;

	int state;

	int ret;

	int ret;

	int timeout = 100;

	int timeout = i2c_adap->timeout;





	while ((state = pca_status(adap)) != 0xf8 && timeout--) {

	while ((state = pca_status(adap)) != 0xf8 && timeout--) {

		msleep(10);

		msleep(10);
@@ -317,7 +305,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap, 
			pca_reset(adap);

			pca_reset(adap);

			goto out;

			goto out;

		default:

		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;

			break;

		}

		}
@@ -337,53 +325,65 @@ static u32 pca_func(struct i2c_adapter *adap) 
        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;

        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};

	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);

	pca_reset(pca_data);

	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_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 */

	udelay(500); /* 500 us for oscilator to stabilise */





	return 0;

	return 0;

}

}





static const struct i2c_algorithm pca_algo = {

	.master_xfer	= pca_xfer,

	.functionality	= pca_func,

};



/*

/*

 * registering functions to load algorithms at runtime

 * registering functions to load algorithms at runtime

 */

 */

int i2c_pca_add_bus(struct i2c_adapter *adap)

int i2c_pca_add_bus(struct i2c_adapter *adap)

{

{

	struct i2c_algo_pca_data *pca_adap = adap->algo_data;

	int rval;

	int rval;





	/* register new adapter to i2c module... */

	rval = pca_init(adap);

	adap->algo = &pca_algo;

	if (rval)



	adap->timeout = 100;		/* default values, should	*/

	adap->retries = 3;		/* be replaced by defines	*/



	if ((rval = pca_init(pca_adap)))

		return rval;

		return rval;





	rval = i2c_add_adapter(adap);

	return i2c_add_adapter(adap);

}

EXPORT_SYMBOL(i2c_pca_add_bus);





int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)

{

	int rval;



	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_DESCRIPTION("I2C-Bus PCA9564 algorithm");

MODULE_LICENSE("GPL");

MODULE_LICENSE("GPL");

drivers/i2c/algos/i2c-algo-pca.h

deleted100644 → 0
+0 −26
Original line number Original line Diff line number Diff line 
#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 */

drivers/i2c/busses/i2c-pca-isa.c

+19 −32
Original line number Original line Diff line number Diff line 
/*

/*

 *  i2c-pca-isa.c driver for PCA9564 on ISA boards

 *  i2c-pca-isa.c driver for PCA9564 on ISA boards

 *    Copyright (C) 2004 Arcom Control Systems

 *    Copyright (C) 2004 Arcom Control Systems

 *    Copyright (C) 2008 Pengutronix

 *

 *

 *  This program is free software; you can redistribute it and/or modify

 *  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

 *  it under the terms of the GNU General Public License as published by
@@ -22,11 +23,9 @@ 
#include <linux/module.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/moduleparam.h>

#include <linux/delay.h>

#include <linux/delay.h>

#include <linux/slab.h>

#include <linux/init.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/interrupt.h>

#include <linux/wait.h>

#include <linux/wait.h>



#include <linux/isa.h>

#include <linux/isa.h>

#include <linux/i2c.h>

#include <linux/i2c.h>

#include <linux/i2c-algo-pca.h>

#include <linux/i2c-algo-pca.h>
@@ -34,13 +33,9 @@ 
#include <asm/io.h>

#include <asm/io.h>

#include <asm/irq.h>

#include <asm/irq.h>





#include "../algos/i2c-algo-pca.h"

#define DRIVER "i2c-pca-isa"



#define IO_SIZE 4

#define IO_SIZE 4





#undef DEBUG_IO

//#define DEBUG_IO



static unsigned long base   = 0x330;

static unsigned long base   = 0x330;

static int irq 	  = 10;

static int irq 	  = 10;
@@ -48,22 +43,9 @@ static int irq = 10; 
 * in the actual clock rate */

 * in the actual clock rate */

static int clock  = I2C_PCA_CON_59kHz;

static int clock  = I2C_PCA_CON_59kHz;





static int own    = 0x55;



static wait_queue_head_t pca_wait;

static wait_queue_head_t pca_wait;





static int pca_isa_getown(struct i2c_algo_pca_data *adap)

static void pca_isa_writebyte(void *pd, int reg, int val)

{

	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)

{

{

#ifdef DEBUG_IO

#ifdef DEBUG_IO

	static char *names[] = { "T/O", "DAT", "ADR", "CON" };

	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);

	outb(val, base+reg);

}

}





static int

static int pca_isa_readbyte(void *pd, int reg)

pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg)

{

{

	int res = inb(base+reg);

	int res = inb(base+reg);

#ifdef DEBUG_IO

#ifdef DEBUG_IO
@@ -85,31 +66,37 @@ pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg) 
	return res;

	return res;

}

}





static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap)

static int pca_isa_waitforcompletion(void *pd)

{

{

	int ret = 0;

	int ret = 0;





	if (irq > -1) {

	if (irq > -1) {

		ret = wait_event_interruptible(pca_wait,

		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 {

	} 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);

			udelay(100);

	}

	}

	return ret;

	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) {

static irqreturn_t pca_handler(int this_irq, void *dev_id) {

	wake_up_interruptible(&pca_wait);

	wake_up_interruptible(&pca_wait);

	return IRQ_HANDLED;

	return IRQ_HANDLED;

}

}





static struct i2c_algo_pca_data pca_isa_data = {

static struct i2c_algo_pca_data pca_isa_data = {

	.get_own		= pca_isa_getown,

	/* .data intentionally left NULL, not needed with ISA */

	.get_clock		= pca_isa_getclock,

	.write_byte		= pca_isa_writebyte,

	.write_byte		= pca_isa_writebyte,

	.read_byte		= pca_isa_readbyte,

	.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 = {

static struct i2c_adapter pca_isa_ops = {
@@ -117,6 +104,7 @@ static struct i2c_adapter pca_isa_ops = { 
	.id		= I2C_HW_A_ISA,

	.id		= I2C_HW_A_ISA,

	.algo_data	= &pca_isa_data,

	.algo_data	= &pca_isa_data,

	.name		= "PCA9564 ISA Adapter",

	.name		= "PCA9564 ISA Adapter",

	.timeout	= 100,

};

};





static int __devinit pca_isa_probe(struct device *dev, unsigned int id)

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) {

	if (i2c_pca_add_bus(&pca_isa_ops) < 0) {

		dev_err(dev, "Failed to add i2c bus\n");

		dev_err(dev, "Failed to add i2c bus\n");

		goto out_irq;

		goto out_irq;
@@ -178,7 +167,7 @@ static struct isa_driver pca_isa_driver = { 
	.remove		= __devexit_p(pca_isa_remove),

	.remove		= __devexit_p(pca_isa_remove),

	.driver = {

	.driver = {

		.owner	= THIS_MODULE,

		.owner	= THIS_MODULE,

		.name	= "i2c-pca-isa",

		.name	= DRIVER,

	}

	}

};

};
@@ -204,7 +193,5 @@ MODULE_PARM_DESC(irq, "IRQ"); 
module_param(clock, int, 0);

module_param(clock, int, 0);

MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet");

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_init(pca_isa_init);

module_exit(pca_isa_exit);
 
module_exit(pca_isa_exit);

include/linux/i2c-algo-pca.h

+32 −5
Original line number Original line Diff line number Diff line 
#ifndef _LINUX_I2C_ALGO_PCA_H

#ifndef _LINUX_I2C_ALGO_PCA_H

#define _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 {

struct i2c_algo_pca_data {

	int  (*get_own)			(struct i2c_algo_pca_data *adap); /* Obtain own address */

	void 				*data;	/* private low level data */

	int  (*get_clock)		(struct i2c_algo_pca_data *adap);

	void (*write_byte)		(void *data, int reg, int val);

	void (*write_byte)		(struct i2c_algo_pca_data *adap, int reg, int val);

	int  (*read_byte)		(void *data, int reg);

	int  (*read_byte)		(struct i2c_algo_pca_data *adap, int reg);

	int  (*wait_for_completion)	(void *data);

	int  (*wait_for_interrupt)	(struct i2c_algo_pca_data *adap);

	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_bus(struct i2c_adapter *);

int i2c_pca_add_numbered_bus(struct i2c_adapter *);





#endif /* _LINUX_I2C_ALGO_PCA_H */
 
#endif /* _LINUX_I2C_ALGO_PCA_H */