377 lines
8.4 KiB
C
377 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
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*
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* Copyright (C) 2011 Weinmann Medical GmbH
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* Author: Nikolaus Voss <n.voss@weinmann.de>
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*
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* Evolved from original work by:
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* Copyright (C) 2004 Rick Bronson
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* Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
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*
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* Borrowed heavily from original work by:
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* Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
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*/
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/pinctrl/consumer.h>
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#include "i2c-at91.h"
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unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
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{
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return readl_relaxed(dev->base + reg);
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}
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void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
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{
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writel_relaxed(val, dev->base + reg);
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}
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void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
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{
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at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
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}
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void at91_twi_irq_save(struct at91_twi_dev *dev)
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{
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dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
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at91_disable_twi_interrupts(dev);
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}
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void at91_twi_irq_restore(struct at91_twi_dev *dev)
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{
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at91_twi_write(dev, AT91_TWI_IER, dev->imr);
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}
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void at91_init_twi_bus(struct at91_twi_dev *dev)
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{
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at91_disable_twi_interrupts(dev);
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at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
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if (dev->slave_detected)
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at91_init_twi_bus_slave(dev);
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else
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at91_init_twi_bus_master(dev);
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}
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static struct at91_twi_pdata at91rm9200_config = {
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.clk_max_div = 5,
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.clk_offset = 3,
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.has_unre_flag = true,
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.has_alt_cmd = false,
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.has_hold_field = false,
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};
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static struct at91_twi_pdata at91sam9261_config = {
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.clk_max_div = 5,
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.clk_offset = 4,
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.has_unre_flag = false,
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.has_alt_cmd = false,
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.has_hold_field = false,
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};
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static struct at91_twi_pdata at91sam9260_config = {
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.clk_max_div = 7,
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.clk_offset = 4,
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.has_unre_flag = false,
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.has_alt_cmd = false,
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.has_hold_field = false,
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};
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static struct at91_twi_pdata at91sam9g20_config = {
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.clk_max_div = 7,
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.clk_offset = 4,
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.has_unre_flag = false,
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.has_alt_cmd = false,
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.has_hold_field = false,
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};
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static struct at91_twi_pdata at91sam9g10_config = {
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.clk_max_div = 7,
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.clk_offset = 4,
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.has_unre_flag = false,
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.has_alt_cmd = false,
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.has_hold_field = false,
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};
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static const struct platform_device_id at91_twi_devtypes[] = {
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{
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.name = "i2c-at91rm9200",
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.driver_data = (unsigned long) &at91rm9200_config,
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}, {
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.name = "i2c-at91sam9261",
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.driver_data = (unsigned long) &at91sam9261_config,
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}, {
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.name = "i2c-at91sam9260",
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.driver_data = (unsigned long) &at91sam9260_config,
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}, {
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.name = "i2c-at91sam9g20",
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.driver_data = (unsigned long) &at91sam9g20_config,
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}, {
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.name = "i2c-at91sam9g10",
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.driver_data = (unsigned long) &at91sam9g10_config,
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}, {
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/* sentinel */
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}
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};
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#if defined(CONFIG_OF)
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static struct at91_twi_pdata at91sam9x5_config = {
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.clk_max_div = 7,
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.clk_offset = 4,
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.has_unre_flag = false,
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.has_alt_cmd = false,
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.has_hold_field = false,
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};
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static struct at91_twi_pdata sama5d4_config = {
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.clk_max_div = 7,
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.clk_offset = 4,
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.has_unre_flag = false,
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.has_alt_cmd = false,
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.has_hold_field = true,
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};
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static struct at91_twi_pdata sama5d2_config = {
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.clk_max_div = 7,
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.clk_offset = 3,
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.has_unre_flag = true,
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.has_alt_cmd = true,
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.has_hold_field = true,
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};
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static const struct of_device_id atmel_twi_dt_ids[] = {
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{
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.compatible = "atmel,at91rm9200-i2c",
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.data = &at91rm9200_config,
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}, {
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.compatible = "atmel,at91sam9260-i2c",
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.data = &at91sam9260_config,
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}, {
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.compatible = "atmel,at91sam9261-i2c",
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.data = &at91sam9261_config,
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}, {
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.compatible = "atmel,at91sam9g20-i2c",
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.data = &at91sam9g20_config,
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}, {
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.compatible = "atmel,at91sam9g10-i2c",
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.data = &at91sam9g10_config,
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}, {
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.compatible = "atmel,at91sam9x5-i2c",
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.data = &at91sam9x5_config,
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}, {
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.compatible = "atmel,sama5d4-i2c",
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.data = &sama5d4_config,
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}, {
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.compatible = "atmel,sama5d2-i2c",
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.data = &sama5d2_config,
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}, {
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/* sentinel */
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}
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};
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MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
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#endif
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static struct at91_twi_pdata *at91_twi_get_driver_data(
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struct platform_device *pdev)
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{
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if (pdev->dev.of_node) {
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const struct of_device_id *match;
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match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
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if (!match)
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return NULL;
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return (struct at91_twi_pdata *)match->data;
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}
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return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
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}
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static int at91_twi_probe(struct platform_device *pdev)
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{
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struct at91_twi_dev *dev;
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struct resource *mem;
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int rc;
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u32 phy_addr;
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dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
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if (!dev)
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return -ENOMEM;
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dev->dev = &pdev->dev;
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!mem)
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return -ENODEV;
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phy_addr = mem->start;
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dev->pdata = at91_twi_get_driver_data(pdev);
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if (!dev->pdata)
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return -ENODEV;
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dev->base = devm_ioremap_resource(&pdev->dev, mem);
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if (IS_ERR(dev->base))
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return PTR_ERR(dev->base);
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dev->irq = platform_get_irq(pdev, 0);
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if (dev->irq < 0)
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return dev->irq;
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platform_set_drvdata(pdev, dev);
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dev->clk = devm_clk_get(dev->dev, NULL);
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if (IS_ERR(dev->clk)) {
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dev_err(dev->dev, "no clock defined\n");
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return -ENODEV;
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}
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clk_prepare_enable(dev->clk);
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snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
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i2c_set_adapdata(&dev->adapter, dev);
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dev->adapter.owner = THIS_MODULE;
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dev->adapter.class = I2C_CLASS_DEPRECATED;
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dev->adapter.dev.parent = dev->dev;
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dev->adapter.nr = pdev->id;
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dev->adapter.timeout = AT91_I2C_TIMEOUT;
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dev->adapter.dev.of_node = pdev->dev.of_node;
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dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
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if (dev->slave_detected)
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rc = at91_twi_probe_slave(pdev, phy_addr, dev);
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else
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rc = at91_twi_probe_master(pdev, phy_addr, dev);
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if (rc)
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return rc;
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at91_init_twi_bus(dev);
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pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
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pm_runtime_use_autosuspend(dev->dev);
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pm_runtime_set_active(dev->dev);
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pm_runtime_enable(dev->dev);
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rc = i2c_add_numbered_adapter(&dev->adapter);
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if (rc) {
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clk_disable_unprepare(dev->clk);
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pm_runtime_disable(dev->dev);
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pm_runtime_set_suspended(dev->dev);
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return rc;
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}
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dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
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at91_twi_read(dev, AT91_TWI_VER));
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return 0;
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}
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static int at91_twi_remove(struct platform_device *pdev)
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{
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struct at91_twi_dev *dev = platform_get_drvdata(pdev);
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i2c_del_adapter(&dev->adapter);
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clk_disable_unprepare(dev->clk);
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pm_runtime_disable(dev->dev);
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pm_runtime_set_suspended(dev->dev);
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return 0;
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}
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#ifdef CONFIG_PM
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static int at91_twi_runtime_suspend(struct device *dev)
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{
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struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
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clk_disable_unprepare(twi_dev->clk);
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pinctrl_pm_select_sleep_state(dev);
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return 0;
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}
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static int at91_twi_runtime_resume(struct device *dev)
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{
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struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
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pinctrl_pm_select_default_state(dev);
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return clk_prepare_enable(twi_dev->clk);
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}
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static int at91_twi_suspend_noirq(struct device *dev)
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{
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if (!pm_runtime_status_suspended(dev))
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at91_twi_runtime_suspend(dev);
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return 0;
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}
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static int at91_twi_resume_noirq(struct device *dev)
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{
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struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
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int ret;
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if (!pm_runtime_status_suspended(dev)) {
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ret = at91_twi_runtime_resume(dev);
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if (ret)
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return ret;
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}
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pm_runtime_mark_last_busy(dev);
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pm_request_autosuspend(dev);
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at91_init_twi_bus(twi_dev);
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return 0;
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}
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static const struct dev_pm_ops at91_twi_pm = {
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.suspend_noirq = at91_twi_suspend_noirq,
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.resume_noirq = at91_twi_resume_noirq,
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.runtime_suspend = at91_twi_runtime_suspend,
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.runtime_resume = at91_twi_runtime_resume,
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};
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#define at91_twi_pm_ops (&at91_twi_pm)
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#else
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#define at91_twi_pm_ops NULL
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#endif
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static struct platform_driver at91_twi_driver = {
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.probe = at91_twi_probe,
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.remove = at91_twi_remove,
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.id_table = at91_twi_devtypes,
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.driver = {
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.name = "at91_i2c",
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.of_match_table = of_match_ptr(atmel_twi_dt_ids),
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.pm = at91_twi_pm_ops,
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},
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};
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static int __init at91_twi_init(void)
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{
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return platform_driver_register(&at91_twi_driver);
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}
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static void __exit at91_twi_exit(void)
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{
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platform_driver_unregister(&at91_twi_driver);
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}
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subsys_initcall(at91_twi_init);
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module_exit(at91_twi_exit);
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MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
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MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:at91_i2c");
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