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Commit ca382f5b authored by Tim Sander's avatar Tim Sander Committed by Wolfram Sang
Browse files

i2c: designware: add i2c gpio recovery option 



This patch contains much input from Phil Reid and has been tested
on Intel/Altera Cyclone V SOC Hardware with Altera GPIO's for the
SCL and SDA GPIO's.

Acked-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarTim Sander <tim@krieglstein.org>
Signed-off-by: default avatarPhil Reid <preid@electromag.com.au>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 0326f9f8

drivers/i2c/busses/i2c-designware-common.c

+5 −1
Original line number Original line Diff line number Diff line
@@ -230,7 +230,11 @@ int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev) 
	while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {

	while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {

		if (timeout <= 0) {

		if (timeout <= 0) {

			dev_warn(dev->dev, "timeout waiting for bus ready\n");

			dev_warn(dev->dev, "timeout waiting for bus ready\n");

			i2c_recover_bus(&dev->adapter);



			if (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY)

				return -ETIMEDOUT;

				return -ETIMEDOUT;

			return 0;

		}

		}

		timeout--;

		timeout--;

		usleep_range(1000, 1100);

		usleep_range(1000, 1100);

drivers/i2c/busses/i2c-designware-core.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -286,6 +286,7 @@ struct dw_i2c_dev { 
	void			(*disable_int)(struct dw_i2c_dev *dev);

	void			(*disable_int)(struct dw_i2c_dev *dev);

	int			(*init)(struct dw_i2c_dev *dev);

	int			(*init)(struct dw_i2c_dev *dev);

	int			mode;

	int			mode;

	struct i2c_bus_recovery_info rinfo;

};

};





#define ACCESS_SWAP		0x00000001

#define ACCESS_SWAP		0x00000001

drivers/i2c/busses/i2c-designware-master.c

+57 −0
Original line number Original line Diff line number Diff line
@@ -25,11 +25,13 @@ 
#include <linux/err.h>

#include <linux/err.h>

#include <linux/errno.h>

#include <linux/errno.h>

#include <linux/export.h>

#include <linux/export.h>

#include <linux/gpio/consumer.h>

#include <linux/i2c.h>

#include <linux/i2c.h>

#include <linux/interrupt.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/module.h>

#include <linux/pm_runtime.h>

#include <linux/pm_runtime.h>

#include <linux/reset.h>





#include "i2c-designware-core.h"

#include "i2c-designware-core.h"
@@ -443,6 +445,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
	if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {

	if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {

		dev_err(dev->dev, "controller timed out\n");

		dev_err(dev->dev, "controller timed out\n");

		/* i2c_dw_init implicitly disables the adapter */

		/* i2c_dw_init implicitly disables the adapter */

		i2c_recover_bus(&dev->adapter);

		i2c_dw_init_master(dev);

		i2c_dw_init_master(dev);

		ret = -ETIMEDOUT;

		ret = -ETIMEDOUT;

		goto done;

		goto done;
@@ -613,6 +616,56 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) 
	return IRQ_HANDLED;

	return IRQ_HANDLED;

}

}





static void i2c_dw_prepare_recovery(struct i2c_adapter *adap)

{

	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);



	i2c_dw_disable(dev);

	reset_control_assert(dev->rst);

	i2c_dw_prepare_clk(dev, false);

}



static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)

{

	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);



	i2c_dw_prepare_clk(dev, true);

	reset_control_deassert(dev->rst);

	i2c_dw_init_master(dev);

}



static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)

{

	struct i2c_bus_recovery_info *rinfo = &dev->rinfo;

	struct i2c_adapter *adap = &dev->adapter;

	struct gpio_desc *gpio;

	int r;



	gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH);

	if (IS_ERR(gpio)) {

		r = PTR_ERR(gpio);

		if (r == -ENOENT)

			return 0;

		return r;

	}

	rinfo->scl_gpiod = gpio;



	gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);

	if (IS_ERR(gpio))

		return PTR_ERR(gpio);

	rinfo->sda_gpiod = gpio;



	rinfo->recover_bus = i2c_generic_scl_recovery;

	rinfo->prepare_recovery = i2c_dw_prepare_recovery;

	rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;

	adap->bus_recovery_info = rinfo;



	dev_info(dev->dev, "running with gpio recovery mode! scl%s",

		 rinfo->sda_gpiod ? ",sda" : "");



	return 0;

}



int i2c_dw_probe(struct dw_i2c_dev *dev)

int i2c_dw_probe(struct dw_i2c_dev *dev)

{

{

	struct i2c_adapter *adap = &dev->adapter;

	struct i2c_adapter *adap = &dev->adapter;
@@ -652,6 +705,10 @@ int i2c_dw_probe(struct dw_i2c_dev *dev) 
		return ret;

		return ret;

	}

	}





	ret = i2c_dw_init_recovery_info(dev);

	if (ret)

		return ret;



	/*

	/*

	 * Increment PM usage count during adapter registration in order to

	 * Increment PM usage count during adapter registration in order to

	 * avoid possible spurious runtime suspend when adapter device is

	 * avoid possible spurious runtime suspend when adapter device is