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Commit 24e9e157 authored by Patrice Chotard's avatar Patrice Chotard Committed by Wolfram Sang
Browse files

i2c: nomadik: adopt pinctrl support 



Amend the I2C nomadik pin controller to optionally take a pin control
handle and set the state of the pins to:

- "default" on boot, resume and before performing an i2c transfer
- "idle" after initial default, after resume default, and after each
   i2c xfer
- "sleep" on suspend()

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle, and for runtime cases inbetween
I2C transfers.

Signed-off-by: default avatarPatrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
[wsa: fixed braces on one else-branch]
Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent 631056c3

drivers/i2c/busses/i2c-nomadik.c

+89 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/platform_data/i2c-nomadik.h>

#include <linux/of.h>

#include <linux/of_i2c.h>

#include <linux/pinctrl/consumer.h>



#define DRIVER_NAME "nmk-i2c"
@@ -147,6 +148,10 @@ struct i2c_nmk_client { 
 * @stop: stop condition.

 * @xfer_complete: acknowledge completion for a I2C message.

 * @result: controller propogated result.

 * @pinctrl: pinctrl handle.

 * @pins_default: default state for the pins.

 * @pins_idle: idle state for the pins.

 * @pins_sleep: sleep state for the pins.

 * @busy: Busy doing transfer.

 */

struct nmk_i2c_dev {
@@ -160,6 +165,11 @@ struct nmk_i2c_dev { 
	int				stop;

	struct completion		xfer_complete;

	int				result;

	/* Three pin states - default, idle & sleep */

	struct pinctrl			*pinctrl;

	struct pinctrl_state		*pins_default;

	struct pinctrl_state		*pins_idle;

	struct pinctrl_state		*pins_sleep;

	bool				busy;

};
@@ -636,6 +646,15 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, 
		goto out_clk;

	}



	/* Optionaly enable pins to be muxed in and configured */

	if (!IS_ERR(dev->pins_default)) {

		status = pinctrl_select_state(dev->pinctrl,

				dev->pins_default);

		if (status)

			dev_err(&dev->adev->dev,

				"could not set default pins\n");

	}



	status = init_hw(dev);

	if (status)

		goto out;
@@ -663,6 +682,15 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, 
out:

	clk_disable_unprepare(dev->clk);

out_clk:

	/* Optionally let pins go into idle state */

	if (!IS_ERR(dev->pins_idle)) {

		status = pinctrl_select_state(dev->pinctrl,

				dev->pins_idle);

		if (status)

			dev_err(&dev->adev->dev,

				"could not set pins to idle state\n");

	}



	pm_runtime_put_sync(&dev->adev->dev);



	dev->busy = false;
@@ -857,15 +885,41 @@ static int nmk_i2c_suspend(struct device *dev) 
{

	struct amba_device *adev = to_amba_device(dev);

	struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);

	int ret;



	if (nmk_i2c->busy)

		return -EBUSY;



	if (!IS_ERR(nmk_i2c->pins_sleep)) {

		ret = pinctrl_select_state(nmk_i2c->pinctrl,

				nmk_i2c->pins_sleep);

		if (ret)

			dev_err(dev, "could not set pins to sleep state\n");

	}



	return 0;

}



static int nmk_i2c_resume(struct device *dev)

{

	struct amba_device *adev = to_amba_device(dev);

	struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);

	int ret;



	/* First go to the default state */

	if (!IS_ERR(nmk_i2c->pins_default)) {

		ret = pinctrl_select_state(nmk_i2c->pinctrl,

				nmk_i2c->pins_default);

		if (ret)

			dev_err(dev, "could not set pins to default state\n");

	}

	/* Then let's idle the pins until the next transfer happens */

	if (!IS_ERR(nmk_i2c->pins_idle)) {

		ret = pinctrl_select_state(nmk_i2c->pinctrl,

				nmk_i2c->pins_idle);

		if (ret)

			dev_err(dev, "could not set pins to idle state\n");

	}

	return 0;

}

#else
@@ -953,6 +1007,40 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id) 
	dev->adev = adev;

	amba_set_drvdata(adev, dev);



	dev->pinctrl = devm_pinctrl_get(&adev->dev);

	if (IS_ERR(dev->pinctrl)) {

		ret = PTR_ERR(dev->pinctrl);

		goto err_pinctrl;

	}



	dev->pins_default = pinctrl_lookup_state(dev->pinctrl,

						 PINCTRL_STATE_DEFAULT);

	if (IS_ERR(dev->pins_default)) {

		dev_err(&adev->dev, "could not get default pinstate\n");

	} else {

		ret = pinctrl_select_state(dev->pinctrl,

					   dev->pins_default);

		if (ret)

			dev_dbg(&adev->dev, "could not set default pinstate\n");

	}



	dev->pins_idle = pinctrl_lookup_state(dev->pinctrl,

					      PINCTRL_STATE_IDLE);

	if (IS_ERR(dev->pins_idle)) {

		dev_dbg(&adev->dev, "could not get idle pinstate\n");

	} else {

		/* If possible, let's go to idle until the first transfer */

		ret = pinctrl_select_state(dev->pinctrl,

					   dev->pins_idle);

		if (ret)

			dev_dbg(&adev->dev, "could not set idle pinstate\n");

	}



	dev->pins_sleep = pinctrl_lookup_state(dev->pinctrl,

					       PINCTRL_STATE_SLEEP);

	if (IS_ERR(dev->pins_sleep))

		dev_dbg(&adev->dev, "could not get sleep pinstate\n");



	dev->virtbase = ioremap(adev->res.start, resource_size(&adev->res));

	if (!dev->virtbase) {

		ret = -ENOMEM;
@@ -1022,6 +1110,7 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id) 
 err_no_ioremap:

	amba_set_drvdata(adev, NULL);

	kfree(dev);

 err_pinctrl:

 err_no_mem:



	return ret;