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

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
......@@ -632,8 +632,8 @@ config I2C_PCA_ISA
select I2C_ALGOPCA
default n
help
This driver supports ISA boards using the Philips PCA 9564
Parallel bus to I2C bus controller
This driver supports ISA boards using the 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-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
......
......@@ -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
......
/*
* 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);
#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 */
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