291 lines
6.4 KiB
C
291 lines
6.4 KiB
C
/*
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* i2c_pca_platform.c
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*
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* Platform driver for the PCA9564 I2C controller.
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*
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* Copyright (C) 2008 Pengutronix
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/jiffies.h>
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/i2c-algo-pca.h>
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#include <linux/i2c-pca-platform.h>
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#include <linux/gpio.h>
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#include <linux/io.h>
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#include <asm/irq.h>
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struct i2c_pca_pf_data {
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void __iomem *reg_base;
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int irq; /* if 0, use polling */
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int gpio;
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wait_queue_head_t wait;
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struct i2c_adapter adap;
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struct i2c_algo_pca_data algo_data;
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unsigned long io_base;
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unsigned long io_size;
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};
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/* Read/Write functions for different register alignments */
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static int i2c_pca_pf_readbyte8(void *pd, int reg)
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{
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struct i2c_pca_pf_data *i2c = pd;
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return ioread8(i2c->reg_base + reg);
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}
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static int i2c_pca_pf_readbyte16(void *pd, int reg)
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{
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struct i2c_pca_pf_data *i2c = pd;
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return ioread8(i2c->reg_base + reg * 2);
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}
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static int i2c_pca_pf_readbyte32(void *pd, int reg)
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{
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struct i2c_pca_pf_data *i2c = pd;
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return ioread8(i2c->reg_base + reg * 4);
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}
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static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)
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{
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struct i2c_pca_pf_data *i2c = pd;
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iowrite8(val, i2c->reg_base + reg);
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}
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static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)
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{
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struct i2c_pca_pf_data *i2c = pd;
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iowrite8(val, i2c->reg_base + reg * 2);
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}
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static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
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{
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struct i2c_pca_pf_data *i2c = pd;
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iowrite8(val, i2c->reg_base + reg * 4);
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}
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static int i2c_pca_pf_waitforcompletion(void *pd)
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{
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struct i2c_pca_pf_data *i2c = pd;
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unsigned long timeout;
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long ret;
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if (i2c->irq) {
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ret = wait_event_timeout(i2c->wait,
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i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
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& I2C_PCA_CON_SI, i2c->adap.timeout);
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} else {
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/* Do polling */
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timeout = jiffies + i2c->adap.timeout;
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do {
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ret = time_before(jiffies, timeout);
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if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
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& I2C_PCA_CON_SI)
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break;
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udelay(100);
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} while (ret);
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}
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return ret > 0;
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}
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static void i2c_pca_pf_dummyreset(void *pd)
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{
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struct i2c_pca_pf_data *i2c = pd;
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printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n",
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i2c->adap.name);
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}
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static void i2c_pca_pf_resetchip(void *pd)
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{
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struct i2c_pca_pf_data *i2c = pd;
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gpio_set_value(i2c->gpio, 0);
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ndelay(100);
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gpio_set_value(i2c->gpio, 1);
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}
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static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)
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{
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struct i2c_pca_pf_data *i2c = dev_id;
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if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
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return IRQ_NONE;
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wake_up(&i2c->wait);
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return IRQ_HANDLED;
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}
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static int i2c_pca_pf_probe(struct platform_device *pdev)
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{
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struct i2c_pca_pf_data *i2c;
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struct resource *res;
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struct i2c_pca9564_pf_platform_data *platform_data =
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dev_get_platdata(&pdev->dev);
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int ret = 0;
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int irq;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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irq = platform_get_irq(pdev, 0);
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/* If irq is 0, we do polling. */
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if (res == NULL) {
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ret = -ENODEV;
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goto e_print;
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}
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if (!request_mem_region(res->start, resource_size(res), res->name)) {
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ret = -ENOMEM;
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goto e_print;
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}
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i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL);
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if (!i2c) {
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ret = -ENOMEM;
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goto e_alloc;
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}
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init_waitqueue_head(&i2c->wait);
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i2c->reg_base = ioremap(res->start, resource_size(res));
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if (!i2c->reg_base) {
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ret = -ENOMEM;
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goto e_remap;
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}
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i2c->io_base = res->start;
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i2c->io_size = resource_size(res);
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i2c->irq = irq;
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i2c->adap.nr = pdev->id;
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i2c->adap.owner = THIS_MODULE;
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snprintf(i2c->adap.name, sizeof(i2c->adap.name),
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"PCA9564/PCA9665 at 0x%08lx",
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(unsigned long) res->start);
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i2c->adap.algo_data = &i2c->algo_data;
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i2c->adap.dev.parent = &pdev->dev;
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if (platform_data) {
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i2c->adap.timeout = platform_data->timeout;
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i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
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i2c->gpio = platform_data->gpio;
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} else {
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i2c->adap.timeout = HZ;
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i2c->algo_data.i2c_clock = 59000;
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i2c->gpio = -1;
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}
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i2c->algo_data.data = i2c;
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i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
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i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
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switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
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case IORESOURCE_MEM_32BIT:
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i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;
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i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;
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break;
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case IORESOURCE_MEM_16BIT:
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i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;
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i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;
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break;
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case IORESOURCE_MEM_8BIT:
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default:
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i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;
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i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;
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break;
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}
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/* Use gpio_is_valid() when in mainline */
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if (i2c->gpio > -1) {
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ret = gpio_request(i2c->gpio, i2c->adap.name);
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if (ret == 0) {
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gpio_direction_output(i2c->gpio, 1);
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i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
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} else {
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printk(KERN_WARNING "%s: Registering gpio failed!\n",
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i2c->adap.name);
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i2c->gpio = ret;
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}
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}
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if (irq) {
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ret = request_irq(irq, i2c_pca_pf_handler,
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IRQF_TRIGGER_FALLING, pdev->name, i2c);
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if (ret)
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goto e_reqirq;
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}
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if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) {
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ret = -ENODEV;
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goto e_adapt;
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}
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platform_set_drvdata(pdev, i2c);
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printk(KERN_INFO "%s registered.\n", i2c->adap.name);
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return 0;
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e_adapt:
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if (irq)
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free_irq(irq, i2c);
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e_reqirq:
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if (i2c->gpio > -1)
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gpio_free(i2c->gpio);
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iounmap(i2c->reg_base);
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e_remap:
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kfree(i2c);
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e_alloc:
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release_mem_region(res->start, resource_size(res));
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e_print:
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printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret);
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return ret;
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}
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static int i2c_pca_pf_remove(struct platform_device *pdev)
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{
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struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);
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i2c_del_adapter(&i2c->adap);
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if (i2c->irq)
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free_irq(i2c->irq, i2c);
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if (i2c->gpio > -1)
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gpio_free(i2c->gpio);
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iounmap(i2c->reg_base);
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release_mem_region(i2c->io_base, i2c->io_size);
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kfree(i2c);
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return 0;
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}
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static struct platform_driver i2c_pca_pf_driver = {
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.probe = i2c_pca_pf_probe,
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.remove = i2c_pca_pf_remove,
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.driver = {
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.name = "i2c-pca-platform",
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},
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};
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module_platform_driver(i2c_pca_pf_driver);
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MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
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MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
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MODULE_LICENSE("GPL");
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