i2c-designware-platdrv.c

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/*
 * Synopsys DesignWare I2C adapter driver (master only).
 *
 * Based on the TI DAVINCI I2C adapter driver.
 *
 * Copyright (C) 2006 Texas Instruments.
 * Copyright (C) 2007 MontaVista Software Inc.
 * Copyright (C) 2009 Provigent Ltd.
 *
 * ----------------------------------------------------------------------------
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 * ----------------------------------------------------------------------------
 *
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/of_i2c.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "i2c-designware-core.h"

static struct i2c_algorithm i2c_dw_algo = {
    .master_xfer    = i2c_dw_xfer,
    .functionality  = i2c_dw_func,
};
static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
{
    return clk_get_rate(dev->clk)/1000;
}

static int __devinit dw_i2c_probe(struct platform_device *pdev)
{
    struct dw_i2c_dev *dev;
    struct i2c_adapter *adap;
    struct resource *mem, *ioarea;
    int irq, r;

    /* NOTE: driver uses the static register mapping */
    mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!mem) {
        dev_err(&pdev->dev, "no mem resource?\n");
        return -EINVAL;
    }

    irq = platform_get_irq(pdev, 0);
    if (irq < 0) {
        dev_err(&pdev->dev, "no irq resource?\n");
        return irq; /* -ENXIO */
    }

    ioarea = request_mem_region(mem->start, resource_size(mem),
            pdev->name);
    if (!ioarea) {
        dev_err(&pdev->dev, "I2C region already claimed\n");
        return -EBUSY;
    }

    dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
    if (!dev) {
        r = -ENOMEM;
        goto err_release_region;
    }

    init_completion(&dev->cmd_complete);
    mutex_init(&dev->lock);
    dev->dev = get_device(&pdev->dev);
    dev->irq = irq;
    platform_set_drvdata(pdev, dev);

    dev->clk = clk_get(&pdev->dev, NULL);
    dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;

    if (IS_ERR(dev->clk)) {
        r = -ENODEV;
        goto err_free_mem;
    }
    clk_prepare_enable(dev->clk);

    dev->functionality =
        I2C_FUNC_I2C |
        I2C_FUNC_10BIT_ADDR |
        I2C_FUNC_SMBUS_BYTE |
        I2C_FUNC_SMBUS_BYTE_DATA |
        I2C_FUNC_SMBUS_WORD_DATA |
        I2C_FUNC_SMBUS_I2C_BLOCK;
    dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
        DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;

    dev->base = ioremap(mem->start, resource_size(mem));
    if (dev->base == NULL) {
        dev_err(&pdev->dev, "failure mapping io resources\n");
        r = -EBUSY;
        goto err_unuse_clocks;
    }
    {
        u32 param1 = i2c_dw_read_comp_param(dev);

        dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
        dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
    }
    r = i2c_dw_init(dev);
    if (r)
        goto err_iounmap;

    i2c_dw_disable_int(dev);
    r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
    if (r) {
        dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
        goto err_iounmap;
    }

    adap = &dev->adapter;
    i2c_set_adapdata(adap, dev);
    adap->owner = THIS_MODULE;
    adap->class = I2C_CLASS_HWMON;
    strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
            sizeof(adap->name));
    adap->algo = &i2c_dw_algo;
    adap->dev.parent = &pdev->dev;
    adap->dev.of_node = pdev->dev.of_node;

    adap->nr = pdev->id;
    r = i2c_add_numbered_adapter(adap);
    if (r) {
        dev_err(&pdev->dev, "failure adding adapter\n");
        goto err_free_irq;
    }
    of_i2c_register_devices(adap);

    return 0;

err_free_irq:
    free_irq(dev->irq, dev);
err_iounmap:
    iounmap(dev->base);
err_unuse_clocks:
    clk_disable_unprepare(dev->clk);
    clk_put(dev->clk);
    dev->clk = NULL;
err_free_mem:
    platform_set_drvdata(pdev, NULL);
    put_device(&pdev->dev);
    kfree(dev);
err_release_region:
    release_mem_region(mem->start, resource_size(mem));

    return r;
}

static int __devexit dw_i2c_remove(struct platform_device *pdev)
{
    struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
    struct resource *mem;

    platform_set_drvdata(pdev, NULL);
    i2c_del_adapter(&dev->adapter);
    put_device(&pdev->dev);

    clk_disable_unprepare(dev->clk);
    clk_put(dev->clk);
    dev->clk = NULL;

    i2c_dw_disable(dev);
    free_irq(dev->irq, dev);
    kfree(dev);

    mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    release_mem_region(mem->start, resource_size(mem));
    return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id dw_i2c_of_match[] = {
    { .compatible = "snps,designware-i2c", },
    {},
};
MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
#endif

#ifdef CONFIG_PM
static int dw_i2c_suspend(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

    clk_disable_unprepare(i_dev->clk);

    return 0;
}

static int dw_i2c_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

    clk_prepare_enable(i_dev->clk);
    i2c_dw_init(i_dev);

    return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:i2c_designware");

static struct platform_driver dw_i2c_driver = {
    .remove     = __devexit_p(dw_i2c_remove),
    .driver     = {
        .name   = "i2c_designware",
        .owner  = THIS_MODULE,
        .of_match_table = of_match_ptr(dw_i2c_of_match),
        .pm = &dw_i2c_dev_pm_ops,
    },
};

static int __init dw_i2c_init_driver(void)
{
    return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
}
subsys_initcall(dw_i2c_init_driver);

static void __exit dw_i2c_exit_driver(void)
{
    platform_driver_unregister(&dw_i2c_driver);
}
module_exit(dw_i2c_exit_driver);

MODULE_AUTHOR("Baruch Siach <[email protected]>");
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
MODULE_LICENSE("GPL");