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Commit 244fbbb8 authored by Wolfram Sang's avatar Wolfram Sang Committed by Jean Delvare
Browse files

i2c: Add platform driver on top of the new pca-algorithm 



Tested on a blackfin.

Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent c01b0831

drivers/i2c/busses/Kconfig

+13 −2
Original line number Diff line number Diff line
@@ -633,7 +633,7 @@ config I2C_PCA_ISA 
	default n

	help

	  This driver supports ISA boards using the Philips PCA9564

	  Parallel bus to I2C bus controller

	  parallel bus to I2C bus controller.

	  

	  This driver can also be built as a module.  If so, the module

	  will be called i2c-pca-isa.
@@ -643,6 +643,17 @@ config I2C_PCA_ISA 
	  delays when I2C/SMBus chip drivers are loaded (e.g. at boot

	  time).  If unsure, say N.



config I2C_PCA_PLATFORM

	tristate "PCA9564 as platform device"

	select I2C_ALGOPCA

	default n

	help

	  This driver supports a memory mapped Philips PCA9564

	  parallel bus to I2C bus controller.



	  This driver can also be built as a module.  If so, the module

	  will be called i2c-pca-platform.



config I2C_MV64XXX

	tristate "Marvell mv64xxx I2C Controller"

	depends on (MV64X60 || PLAT_ORION) && EXPERIMENTAL

drivers/i2c/busses/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o 
obj-$(CONFIG_I2C_PARPORT_LIGHT)	+= i2c-parport-light.o

obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o

obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o

obj-$(CONFIG_I2C_PCA_PLATFORM)	+= i2c-pca-platform.o

obj-$(CONFIG_I2C_PIIX4)		+= i2c-piix4.o

obj-$(CONFIG_I2C_PMCMSP)	+= i2c-pmcmsp.o

obj-$(CONFIG_I2C_PNX)		+= i2c-pnx.o

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

0 → 100644
+298 −0
Original line number Diff line number Diff line 
/*

 *  i2c_pca_platform.c

 *

 *  Platform driver for the PCA9564 I2C controller.

 *

 *  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 version 2 as

 *  published by the Free Software Foundation.



 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/delay.h>

#include <linux/errno.h>

#include <linux/i2c.h>

#include <linux/interrupt.h>

#include <linux/platform_device.h>

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

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

#include <linux/gpio.h>



#include <asm/irq.h>

#include <asm/io.h>



#define res_len(r)		((r)->end - (r)->start + 1)



struct i2c_pca_pf_data {

	void __iomem			*reg_base;

	int				irq;	/* if 0, use polling */

	int				gpio;

	wait_queue_head_t		wait;

	struct i2c_adapter		adap;

	struct i2c_algo_pca_data	algo_data;

	unsigned long			io_base;

	unsigned long			io_size;

};



/* Read/Write functions for different register alignments */



static int i2c_pca_pf_readbyte8(void *pd, int reg)

{

	struct i2c_pca_pf_data *i2c = pd;

	return ioread8(i2c->reg_base + reg);

}



static int i2c_pca_pf_readbyte16(void *pd, int reg)

{

	struct i2c_pca_pf_data *i2c = pd;

	return ioread8(i2c->reg_base + reg * 2);

}



static int i2c_pca_pf_readbyte32(void *pd, int reg)

{

	struct i2c_pca_pf_data *i2c = pd;

	return ioread8(i2c->reg_base + reg * 4);

}



static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)

{

	struct i2c_pca_pf_data *i2c = pd;

	iowrite8(val, i2c->reg_base + reg);

}



static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)

{

	struct i2c_pca_pf_data *i2c = pd;

	iowrite8(val, i2c->reg_base + reg * 2);

}



static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)

{

	struct i2c_pca_pf_data *i2c = pd;

	iowrite8(val, i2c->reg_base + reg * 4);

}





static int i2c_pca_pf_waitforcompletion(void *pd)

{

	struct i2c_pca_pf_data *i2c = pd;

	int ret = 0;



	if (i2c->irq) {

		ret = wait_event_interruptible(i2c->wait,

			i2c->algo_data.read_byte(i2c, I2C_PCA_CON)

			& I2C_PCA_CON_SI);

	} else {

		/*

		 * Do polling...

		 * XXX: Could get stuck in extreme cases!

		 *      Maybe add timeout, but using irqs is preferred anyhow.

		 */

		while ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)

				& I2C_PCA_CON_SI) == 0)

			udelay(100);

	}



	return ret;

}



static void i2c_pca_pf_dummyreset(void *pd)

{

	struct i2c_pca_pf_data *i2c = pd;

	printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n",

		i2c->adap.name);

}



static void i2c_pca_pf_resetchip(void *pd)

{

	struct i2c_pca_pf_data *i2c = pd;



	gpio_set_value(i2c->gpio, 0);

	ndelay(100);

	gpio_set_value(i2c->gpio, 1);

}



static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)

{

	struct i2c_pca_pf_data *i2c = dev_id;



	if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)

		return IRQ_NONE;



	wake_up_interruptible(&i2c->wait);



	return IRQ_HANDLED;

}





static int __devinit i2c_pca_pf_probe(struct platform_device *pdev)

{

	struct i2c_pca_pf_data *i2c;

	struct resource *res;

	struct i2c_pca9564_pf_platform_data *platform_data =

				pdev->dev.platform_data;

	int ret = 0;

	int irq;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	irq = platform_get_irq(pdev, 0);

	/* If irq is 0, we do polling. */



	if (res == NULL) {

		ret = -ENODEV;

		goto e_print;

	}



	if (!request_mem_region(res->start, res_len(res), res->name)) {

		ret = -ENOMEM;

		goto e_print;

	}



	i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL);

	if (!i2c) {

		ret = -ENOMEM;

		goto e_alloc;

	}



	init_waitqueue_head(&i2c->wait);



	i2c->reg_base = ioremap(res->start, res_len(res));

	if (!i2c->reg_base) {

		ret = -EIO;

		goto e_remap;

	}

	i2c->io_base = res->start;

	i2c->io_size = res_len(res);

	i2c->irq = irq;



	i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0;

	i2c->adap.owner = THIS_MODULE;

	snprintf(i2c->adap.name, sizeof(i2c->adap.name), "PCA9564 at 0x%08lx",

		(unsigned long) res->start);

	i2c->adap.algo_data = &i2c->algo_data;

	i2c->adap.dev.parent = &pdev->dev;

	i2c->adap.timeout = platform_data->timeout;



	i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;

	i2c->algo_data.data = i2c;



	switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {

	case IORESOURCE_MEM_32BIT:

		i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;

		i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;

		break;

	case IORESOURCE_MEM_16BIT:

		i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;

		i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;

		break;

	case IORESOURCE_MEM_8BIT:

	default:

		i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;

		i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;

		break;

	}



	i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;



	i2c->gpio = platform_data->gpio;

	i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;



	/* Use gpio_is_valid() when in mainline */

	if (i2c->gpio > -1) {

		ret = gpio_request(i2c->gpio, i2c->adap.name);

		if (ret == 0) {

			gpio_direction_output(i2c->gpio, 1);

			i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;

		} else {

			printk(KERN_WARNING "%s: Registering gpio failed!\n",

				i2c->adap.name);

			i2c->gpio = ret;

		}

	}



	if (irq) {

		ret = request_irq(irq, i2c_pca_pf_handler,

			IRQF_TRIGGER_FALLING, i2c->adap.name, i2c);

		if (ret)

			goto e_reqirq;

	}



	if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) {

		ret = -ENODEV;

		goto e_adapt;

	}



	platform_set_drvdata(pdev, i2c);



	printk(KERN_INFO "%s registered.\n", i2c->adap.name);



	return 0;



e_adapt:

	if (irq)

		free_irq(irq, i2c);

e_reqirq:

	if (i2c->gpio > -1)

		gpio_free(i2c->gpio);



	iounmap(i2c->reg_base);

e_remap:

	kfree(i2c);

e_alloc:

	release_mem_region(res->start, res_len(res));

e_print:

	printk(KERN_ERR "Registering PCA9564 FAILED! (%d)\n", ret);

	return ret;

}



static int __devexit i2c_pca_pf_remove(struct platform_device *pdev)

{

	struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);

	platform_set_drvdata(pdev, NULL);



	i2c_del_adapter(&i2c->adap);



	if (i2c->irq)

		free_irq(i2c->irq, i2c);



	if (i2c->gpio > -1)

		gpio_free(i2c->gpio);



	iounmap(i2c->reg_base);

	release_mem_region(i2c->io_base, i2c->io_size);

	kfree(i2c);



	return 0;

}



static struct platform_driver i2c_pca_pf_driver = {

	.probe = i2c_pca_pf_probe,

	.remove = __devexit_p(i2c_pca_pf_remove),

	.driver = {

		.name = "i2c-pca-platform",

		.owner = THIS_MODULE,

	},

};



static int __init i2c_pca_pf_init(void)

{

	return platform_driver_register(&i2c_pca_pf_driver);

}



static void __exit i2c_pca_pf_exit(void)

{

	platform_driver_unregister(&i2c_pca_pf_driver);

}



MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");

MODULE_DESCRIPTION("I2C-PCA9564 platform driver");

MODULE_LICENSE("GPL");



module_init(i2c_pca_pf_init);

module_exit(i2c_pca_pf_exit);

include/linux/i2c-pca-platform.h

0 → 100644
+12 −0
Original line number Diff line number Diff line 
#ifndef I2C_PCA9564_PLATFORM_H

#define I2C_PCA9564_PLATFORM_H



struct i2c_pca9564_pf_platform_data {

	int gpio;		/* pin to reset chip. driver will work when

				 * not supplied (negative value), but it

				 * cannot exit some error conditions then */

	int i2c_clock_speed;	/* values are defined in linux/i2c-algo-pca.h */

	int timeout;		/* timeout = this value * 10us */

};



#endif /* I2C_PCA9564_PLATFORM_H */