You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
290 lines
6.4 KiB
290 lines
6.4 KiB
/* |
|
* 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/slab.h> |
|
#include <linux/delay.h> |
|
#include <linux/jiffies.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 <linux/io.h> |
|
|
|
#include <asm/irq.h> |
|
|
|
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; |
|
unsigned long timeout; |
|
long ret; |
|
|
|
if (i2c->irq) { |
|
ret = wait_event_timeout(i2c->wait, |
|
i2c->algo_data.read_byte(i2c, I2C_PCA_CON) |
|
& I2C_PCA_CON_SI, i2c->adap.timeout); |
|
} else { |
|
/* Do polling */ |
|
timeout = jiffies + i2c->adap.timeout; |
|
do { |
|
ret = time_before(jiffies, timeout); |
|
if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON) |
|
& I2C_PCA_CON_SI) |
|
break; |
|
udelay(100); |
|
} while (ret); |
|
} |
|
|
|
return ret > 0; |
|
} |
|
|
|
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(&i2c->wait); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
|
|
static int 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 = |
|
dev_get_platdata(&pdev->dev); |
|
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, resource_size(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, resource_size(res)); |
|
if (!i2c->reg_base) { |
|
ret = -ENOMEM; |
|
goto e_remap; |
|
} |
|
i2c->io_base = res->start; |
|
i2c->io_size = resource_size(res); |
|
i2c->irq = irq; |
|
|
|
i2c->adap.nr = pdev->id; |
|
i2c->adap.owner = THIS_MODULE; |
|
snprintf(i2c->adap.name, sizeof(i2c->adap.name), |
|
"PCA9564/PCA9665 at 0x%08lx", |
|
(unsigned long) res->start); |
|
i2c->adap.algo_data = &i2c->algo_data; |
|
i2c->adap.dev.parent = &pdev->dev; |
|
|
|
if (platform_data) { |
|
i2c->adap.timeout = platform_data->timeout; |
|
i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed; |
|
i2c->gpio = platform_data->gpio; |
|
} else { |
|
i2c->adap.timeout = HZ; |
|
i2c->algo_data.i2c_clock = 59000; |
|
i2c->gpio = -1; |
|
} |
|
|
|
i2c->algo_data.data = i2c; |
|
i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; |
|
i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset; |
|
|
|
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; |
|
} |
|
|
|
/* 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, pdev->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, resource_size(res)); |
|
e_print: |
|
printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret); |
|
return ret; |
|
} |
|
|
|
static int i2c_pca_pf_remove(struct platform_device *pdev) |
|
{ |
|
struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev); |
|
|
|
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 = i2c_pca_pf_remove, |
|
.driver = { |
|
.name = "i2c-pca-platform", |
|
}, |
|
}; |
|
|
|
module_platform_driver(i2c_pca_pf_driver); |
|
|
|
MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>"); |
|
MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); |
|
MODULE_LICENSE("GPL");
|
|
|