drivers/i2c/busses/i2c-octeon-platdrv.c - arm/linux - Git at Google

 /*
  * (C) Copyright 2009-2010
  * Nokia Siemens Networks, michael.lawnick.ext@nsn.com
  *
  * Portions Copyright (C) 2010 - 2016 Cavium, Inc.
  *
  * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2. This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */

 #include <linux/atomic.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/sched.h>
 #include <linux/slab.h>

 #include <asm/octeon/octeon.h>
 #include "i2c-octeon-core.h"

 #define DRV_NAME "i2c-octeon"

 /**
  * octeon_i2c_int_enable - enable the CORE interrupt
  * @i2c: The struct octeon_i2c
  *
  * The interrupt will be asserted when there is non-STAT_IDLE state in
  * the SW_TWSI_EOP_TWSI_STAT register.
  */
 static void octeon_i2c_int_enable(struct octeon_i2c *i2c)
 {
 	octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN);
 }

 /* disable the CORE interrupt */
 static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
 {
 	/* clear TS/ST/IFLG events */
 	octeon_i2c_write_int(i2c, 0);
 }

 /**
  * octeon_i2c_int_enable78 - enable the CORE interrupt
  * @i2c: The struct octeon_i2c
  *
  * The interrupt will be asserted when there is non-STAT_IDLE state in the
  * SW_TWSI_EOP_TWSI_STAT register.
  */
 static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)
 {
 	atomic_inc_return(&i2c->int_enable_cnt);
 	enable_irq(i2c->irq);
 }

 static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)
 {
 	int count;

 	/*
 	 * The interrupt can be disabled in two places, but we only
 	 * want to make the disable_irq_nosync() call once, so keep
 	 * track with the atomic variable.
 	 */
 	count = atomic_dec_if_positive(cnt);
 	if (count >= 0)
 		disable_irq_nosync(irq);
 }

 /* disable the CORE interrupt */
 static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)
 {
 	__octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq);
 }

 /**
  * octeon_i2c_hlc_int_enable78 - enable the ST interrupt
  * @i2c: The struct octeon_i2c
  *
  * The interrupt will be asserted when there is non-STAT_IDLE state in
  * the SW_TWSI_EOP_TWSI_STAT register.
  */
 static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)
 {
 	atomic_inc_return(&i2c->hlc_int_enable_cnt);
 	enable_irq(i2c->hlc_irq);
 }

 /* disable the ST interrupt */
 static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
 {
 	__octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);
 }

 /* HLC interrupt service routine */
 static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
 {
 	struct octeon_i2c *i2c = dev_id;

 	i2c->hlc_int_disable(i2c);
 	wake_up(&i2c->queue);

 	return IRQ_HANDLED;
 }

 static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
 {
 	octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
 }

 static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
 	       I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
 }

 static const struct i2c_algorithm octeon_i2c_algo = {
 	.master_xfer = octeon_i2c_xfer,
 	.functionality = octeon_i2c_functionality,
 };

 static const struct i2c_adapter octeon_i2c_ops = {
 	.owner = THIS_MODULE,
 	.name = "OCTEON adapter",
 	.algo = &octeon_i2c_algo,
 };

 static int octeon_i2c_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
 	int irq, result = 0, hlc_irq = 0;
 	struct resource *res_mem;
 	struct octeon_i2c *i2c;
 	bool cn78xx_style;

 	cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");
 	if (cn78xx_style) {
 		hlc_irq = platform_get_irq(pdev, 0);
 		if (hlc_irq < 0)
 			return hlc_irq;

 		irq = platform_get_irq(pdev, 2);
 		if (irq < 0)
 			return irq;
 	} else {
 		/* All adaptors have an irq.  */
 		irq = platform_get_irq(pdev, 0);
 		if (irq < 0)
 			return irq;
 	}

 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
 	if (!i2c) {
 		result = -ENOMEM;
 		goto out;
 	}
 	i2c->dev = &pdev->dev;

 	i2c->roff.sw_twsi = 0x00;
 	i2c->roff.twsi_int = 0x10;
 	i2c->roff.sw_twsi_ext = 0x18;

 	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	i2c->twsi_base = devm_ioremap_resource(&pdev->dev, res_mem);
 	if (IS_ERR(i2c->twsi_base)) {
 		result = PTR_ERR(i2c->twsi_base);
 		goto out;
 	}

 	/*
 	 * "clock-rate" is a legacy binding, the official binding is
 	 * "clock-frequency".  Try the official one first and then
 	 * fall back if it doesn't exist.
 	 */
 	if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) &&
 	    of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) {
 		dev_err(i2c->dev,
 			"no I2C 'clock-rate' or 'clock-frequency' property\n");
 		result = -ENXIO;
 		goto out;
 	}

 	i2c->sys_freq = octeon_get_io_clock_rate();

 	init_waitqueue_head(&i2c->queue);

 	i2c->irq = irq;

 	if (cn78xx_style) {
 		i2c->hlc_irq = hlc_irq;

 		i2c->int_enable = octeon_i2c_int_enable78;
 		i2c->int_disable = octeon_i2c_int_disable78;
 		i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78;
 		i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78;

 		irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
 		irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);

 		result = devm_request_irq(&pdev->dev, i2c->hlc_irq,
 					  octeon_i2c_hlc_isr78, 0,
 					  DRV_NAME, i2c);
 		if (result < 0) {
 			dev_err(i2c->dev, "failed to attach interrupt\n");
 			goto out;
 		}
 	} else {
 		i2c->int_enable = octeon_i2c_int_enable;
 		i2c->int_disable = octeon_i2c_int_disable;
 		i2c->hlc_int_enable = octeon_i2c_hlc_int_enable;
 		i2c->hlc_int_disable = octeon_i2c_int_disable;
 	}

 	result = devm_request_irq(&pdev->dev, i2c->irq,
 				  octeon_i2c_isr, 0, DRV_NAME, i2c);
 	if (result < 0) {
 		dev_err(i2c->dev, "failed to attach interrupt\n");
 		goto out;
 	}

 	if (OCTEON_IS_MODEL(OCTEON_CN38XX))
 		i2c->broken_irq_check = true;

 	result = octeon_i2c_init_lowlevel(i2c);
 	if (result) {
 		dev_err(i2c->dev, "init low level failed\n");
 		goto  out;
 	}

 	octeon_i2c_set_clock(i2c);

 	i2c->adap = octeon_i2c_ops;
 	i2c->adap.timeout = msecs_to_jiffies(2);
 	i2c->adap.retries = 5;
 	i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
 	i2c->adap.dev.parent = &pdev->dev;
 	i2c->adap.dev.of_node = node;
 	i2c_set_adapdata(&i2c->adap, i2c);
 	platform_set_drvdata(pdev, i2c);

 	result = i2c_add_adapter(&i2c->adap);
 	if (result < 0)
 		goto out;
 	dev_info(i2c->dev, "probed\n");
 	return 0;

 out:
 	return result;
 };

 static int octeon_i2c_remove(struct platform_device *pdev)
 {
 	struct octeon_i2c *i2c = platform_get_drvdata(pdev);

 	i2c_del_adapter(&i2c->adap);
 	return 0;
 };

 static const struct of_device_id octeon_i2c_match[] = {
 	{ .compatible = "cavium,octeon-3860-twsi", },
 	{ .compatible = "cavium,octeon-7890-twsi", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, octeon_i2c_match);

 static struct platform_driver octeon_i2c_driver = {
 	.probe		= octeon_i2c_probe,
 	.remove		= octeon_i2c_remove,
 	.driver		= {
 		.name	= DRV_NAME,
 		.of_match_table = octeon_i2c_match,
 	},
 };

 module_platform_driver(octeon_i2c_driver);

 MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>");
 MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
 MODULE_LICENSE("GPL");
	/*
	* (C) Copyright 2009-2010
	* Nokia Siemens Networks, michael.lawnick.ext@nsn.com
	*
	* Portions Copyright (C) 2010 - 2016 Cavium, Inc.
	*
	* This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*/

	#include <linux/atomic.h>
	#include <linux/delay.h>
	#include <linux/i2c.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/sched.h>
	#include <linux/slab.h>

	#include <asm/octeon/octeon.h>
	#include "i2c-octeon-core.h"

	#define DRV_NAME "i2c-octeon"

	/**
	* octeon_i2c_int_enable - enable the CORE interrupt
	* @i2c: The struct octeon_i2c
	*
	* The interrupt will be asserted when there is non-STAT_IDLE state in
	* the SW_TWSI_EOP_TWSI_STAT register.
	*/
	static void octeon_i2c_int_enable(struct octeon_i2c *i2c)
	{
	octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN);
	}

	/* disable the CORE interrupt */
	static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
	{
	/* clear TS/ST/IFLG events */
	octeon_i2c_write_int(i2c, 0);
	}

	/**
	* octeon_i2c_int_enable78 - enable the CORE interrupt
	* @i2c: The struct octeon_i2c
	*
	* The interrupt will be asserted when there is non-STAT_IDLE state in the
	* SW_TWSI_EOP_TWSI_STAT register.
	*/
	static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)
	{
	atomic_inc_return(&i2c->int_enable_cnt);
	enable_irq(i2c->irq);
	}

	static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)
	{
	int count;

	/*
	* The interrupt can be disabled in two places, but we only
	* want to make the disable_irq_nosync() call once, so keep
	* track with the atomic variable.
	*/
	count = atomic_dec_if_positive(cnt);
	if (count >= 0)
	disable_irq_nosync(irq);
	}

	/* disable the CORE interrupt */
	static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)
	{
	__octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq);
	}

	/**
	* octeon_i2c_hlc_int_enable78 - enable the ST interrupt
	* @i2c: The struct octeon_i2c
	*
	* The interrupt will be asserted when there is non-STAT_IDLE state in
	* the SW_TWSI_EOP_TWSI_STAT register.
	*/
	static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)
	{
	atomic_inc_return(&i2c->hlc_int_enable_cnt);
	enable_irq(i2c->hlc_irq);
	}

	/* disable the ST interrupt */
	static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
	{
	__octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);
	}

	/* HLC interrupt service routine */
	static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
	{
	struct octeon_i2c *i2c = dev_id;

	i2c->hlc_int_disable(i2c);
	wake_up(&i2c->queue);

	return IRQ_HANDLED;
	}

	static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
	{
	octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
	}

	static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
	{
	return I2C_FUNC_I2C \| (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) \|
	I2C_FUNC_SMBUS_READ_BLOCK_DATA \| I2C_SMBUS_BLOCK_PROC_CALL;
	}

	static const struct i2c_algorithm octeon_i2c_algo = {
	.master_xfer = octeon_i2c_xfer,
	.functionality = octeon_i2c_functionality,
	};

	static const struct i2c_adapter octeon_i2c_ops = {
	.owner = THIS_MODULE,
	.name = "OCTEON adapter",
	.algo = &octeon_i2c_algo,
	};

	static int octeon_i2c_probe(struct platform_device *pdev)
	{
	struct device_node *node = pdev->dev.of_node;
	int irq, result = 0, hlc_irq = 0;
	struct resource *res_mem;
	struct octeon_i2c *i2c;
	bool cn78xx_style;

	cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");
	if (cn78xx_style) {
	hlc_irq = platform_get_irq(pdev, 0);
	if (hlc_irq < 0)
	return hlc_irq;

	irq = platform_get_irq(pdev, 2);
	if (irq < 0)
	return irq;
	} else {
	/* All adaptors have an irq. */
	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;
	}

	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
	if (!i2c) {
	result = -ENOMEM;
	goto out;
	}
	i2c->dev = &pdev->dev;

	i2c->roff.sw_twsi = 0x00;
	i2c->roff.twsi_int = 0x10;
	i2c->roff.sw_twsi_ext = 0x18;

	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	i2c->twsi_base = devm_ioremap_resource(&pdev->dev, res_mem);
	if (IS_ERR(i2c->twsi_base)) {
	result = PTR_ERR(i2c->twsi_base);
	goto out;
	}

	/*
	* "clock-rate" is a legacy binding, the official binding is
	* "clock-frequency". Try the official one first and then
	* fall back if it doesn't exist.
	*/
	if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) &&
	of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) {
	dev_err(i2c->dev,
	"no I2C 'clock-rate' or 'clock-frequency' property\n");
	result = -ENXIO;
	goto out;
	}

	i2c->sys_freq = octeon_get_io_clock_rate();

	init_waitqueue_head(&i2c->queue);

	i2c->irq = irq;

	if (cn78xx_style) {
	i2c->hlc_irq = hlc_irq;

	i2c->int_enable = octeon_i2c_int_enable78;
	i2c->int_disable = octeon_i2c_int_disable78;
	i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78;
	i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78;

	irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
	irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);

	result = devm_request_irq(&pdev->dev, i2c->hlc_irq,
	octeon_i2c_hlc_isr78, 0,
	DRV_NAME, i2c);
	if (result < 0) {
	dev_err(i2c->dev, "failed to attach interrupt\n");
	goto out;
	}
	} else {
	i2c->int_enable = octeon_i2c_int_enable;
	i2c->int_disable = octeon_i2c_int_disable;
	i2c->hlc_int_enable = octeon_i2c_hlc_int_enable;
	i2c->hlc_int_disable = octeon_i2c_int_disable;
	}

	result = devm_request_irq(&pdev->dev, i2c->irq,
	octeon_i2c_isr, 0, DRV_NAME, i2c);
	if (result < 0) {
	dev_err(i2c->dev, "failed to attach interrupt\n");
	goto out;
	}

	if (OCTEON_IS_MODEL(OCTEON_CN38XX))
	i2c->broken_irq_check = true;

	result = octeon_i2c_init_lowlevel(i2c);
	if (result) {
	dev_err(i2c->dev, "init low level failed\n");
	goto out;
	}

	octeon_i2c_set_clock(i2c);

	i2c->adap = octeon_i2c_ops;
	i2c->adap.timeout = msecs_to_jiffies(2);
	i2c->adap.retries = 5;
	i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
	i2c->adap.dev.parent = &pdev->dev;
	i2c->adap.dev.of_node = node;
	i2c_set_adapdata(&i2c->adap, i2c);
	platform_set_drvdata(pdev, i2c);

	result = i2c_add_adapter(&i2c->adap);
	if (result < 0)
	goto out;
	dev_info(i2c->dev, "probed\n");
	return 0;

	out:
	return result;
	};

	static int octeon_i2c_remove(struct platform_device *pdev)
	{
	struct octeon_i2c *i2c = platform_get_drvdata(pdev);

	i2c_del_adapter(&i2c->adap);
	return 0;
	};

	static const struct of_device_id octeon_i2c_match[] = {
	{ .compatible = "cavium,octeon-3860-twsi", },
	{ .compatible = "cavium,octeon-7890-twsi", },
	{},
	};
	MODULE_DEVICE_TABLE(of, octeon_i2c_match);

	static struct platform_driver octeon_i2c_driver = {
	.probe = octeon_i2c_probe,
	.remove = octeon_i2c_remove,
	.driver = {
	.name = DRV_NAME,
	.of_match_table = octeon_i2c_match,
	},
	};

	module_platform_driver(octeon_i2c_driver);

	MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>");
	MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
	MODULE_LICENSE("GPL");