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Commit e6403b7c authored by Mark A. Greer's avatar Mark A. Greer Committed by Samuel Ortiz
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NFC: trf7970a: Add pm_runtime support 



Add pm_runtime support by moving the code that enables the trf7970a to
the pm_runtime hook routines. The pm_runtime 'autosuspend' feature is
used so that the device isn't disabled until at least 30 seconds have
passed since trf7970a_switch_rf_off() was last called.

The result is that when trf7970a_switch_rf_on() is called, the device
will be enabled and initialized (if it isn't already).  When
trf7970a_switch_rf_off() is called, it will turn off the RF immediately
but leave the device enabled for at least 30 seconds.
If 30 seconds have passed and the pm_runtime facility decides to suspend
the driver, the device will be disabled then.

Signed-off-by: default avatarMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent a1d2dc5b

drivers/nfc/trf7970a.c

+85 −37
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/device.h>

#include <linux/netdevice.h>

#include <linux/interrupt.h>

#include <linux/pm_runtime.h>

#include <linux/nfc.h>

#include <linux/skbuff.h>

#include <linux/delay.h>
@@ -106,6 +107,8 @@ 
		(NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |	\

		 NFC_PROTO_ISO15693_MASK)



#define TRF7970A_AUTOSUSPEND_DELAY		30000 /* 30 seconds */



/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends

 * on what the current framing is, the address of the TX length byte 1

 * register (0x1d), and the 2 byte length of the data to be transmitted.
@@ -330,7 +333,6 @@ struct trf7970a { 
	struct regulator		*regulator;

	struct nfc_digital_dev		*ddev;

	u32				quirks;

	bool				powering_up;

	bool				aborting;

	struct sk_buff			*tx_skb;

	struct sk_buff			*rx_skb;
@@ -795,47 +797,22 @@ static void trf7970a_switch_rf_off(struct trf7970a *trf) 


	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);



	gpio_set_value(trf->en_gpio, 0);

	gpio_set_value(trf->en2_gpio, 0);



	trf->aborting = false;

	trf->state = TRF7970A_ST_OFF;



	pm_runtime_mark_last_busy(trf->dev);

	pm_runtime_put_autosuspend(trf->dev);

}



static int trf7970a_switch_rf_on(struct trf7970a *trf)

{

	unsigned long delay;

	int ret;



	dev_dbg(trf->dev, "Switching rf on\n");



	if (trf->powering_up)

		usleep_range(5000, 6000);

	pm_runtime_get_sync(trf->dev);



	gpio_set_value(trf->en2_gpio, 1);

	usleep_range(1000, 2000);

	gpio_set_value(trf->en_gpio, 1);



	/* The delay between enabling the trf7970a and issuing the first

	 * command is significantly longer the very first time after powering

	 * up.  Make sure the longer delay is only done the first time.

	 */

	if (trf->powering_up) {

		delay = 20000;

		trf->powering_up = false;

	} else {

		delay = 5000;

	}



	usleep_range(delay, delay + 1000);



	ret = trf7970a_init(trf);

	if (ret)

		trf7970a_switch_rf_off(trf);

	else

	trf->state = TRF7970A_ST_IDLE;



	return ret;

	return 0;

}



static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
@@ -1331,8 +1308,6 @@ static int trf7970a_probe(struct spi_device *spi) 
	if (uvolts > 4000000)

		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;



	trf->powering_up = true;



	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,

			TRF7970A_SUPPORTED_PROTOCOLS,

			NFC_DIGITAL_DRV_CAPS_IN_CRC, TRF7970A_TX_SKB_HEADROOM,
@@ -1347,6 +1322,10 @@ static int trf7970a_probe(struct spi_device *spi) 
	nfc_digital_set_drvdata(trf->ddev, trf);

	spi_set_drvdata(spi, trf);



	pm_runtime_set_autosuspend_delay(trf->dev, TRF7970A_AUTOSUSPEND_DELAY);

	pm_runtime_use_autosuspend(trf->dev);

	pm_runtime_enable(trf->dev);



	ret = nfc_digital_register_device(trf->ddev);

	if (ret) {

		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
@@ -1357,6 +1336,7 @@ static int trf7970a_probe(struct spi_device *spi) 
	return 0;



err_free_ddev:

	pm_runtime_disable(trf->dev);

	nfc_digital_free_device(trf->ddev);

err_disable_regulator:

	regulator_disable(trf->regulator);
@@ -1371,15 +1351,16 @@ static int trf7970a_remove(struct spi_device *spi) 


	mutex_lock(&trf->lock);



	trf7970a_switch_rf_off(trf);

	trf7970a_init(trf);



	switch (trf->state) {

	case TRF7970A_ST_WAIT_FOR_TX_FIFO:

	case TRF7970A_ST_WAIT_FOR_RX_DATA:

	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:

	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:

		trf7970a_send_err_upstream(trf, -ECANCELED);

		/* FALLTHROUGH */

	case TRF7970A_ST_IDLE:

	case TRF7970A_ST_IDLE_RX_BLOCKED:

		pm_runtime_put_sync(trf->dev);

		break;

	default:

		break;
@@ -1387,6 +1368,8 @@ static int trf7970a_remove(struct spi_device *spi) 


	mutex_unlock(&trf->lock);



	pm_runtime_disable(trf->dev);



	nfc_digital_unregister_device(trf->ddev);

	nfc_digital_free_device(trf->ddev);
@@ -1397,6 +1380,70 @@ static int trf7970a_remove(struct spi_device *spi) 
	return 0;

}



#ifdef CONFIG_PM_RUNTIME

static int trf7970a_pm_runtime_suspend(struct device *dev)

{

	struct spi_device *spi = container_of(dev, struct spi_device, dev);

	struct trf7970a *trf = spi_get_drvdata(spi);

	int ret;



	dev_dbg(dev, "Runtime suspend\n");



	if (trf->state != TRF7970A_ST_OFF) {

		dev_dbg(dev, "Can't suspend - not in OFF state (%d)\n",

				trf->state);

		return -EBUSY;

	}



	gpio_set_value(trf->en_gpio, 0);

	gpio_set_value(trf->en2_gpio, 0);



	ret = regulator_disable(trf->regulator);

	if (ret)

		dev_err(dev, "%s - Can't disable VIN: %d\n", __func__, ret);



	return ret;

}



static int trf7970a_pm_runtime_resume(struct device *dev)

{

	struct spi_device *spi = container_of(dev, struct spi_device, dev);

	struct trf7970a *trf = spi_get_drvdata(spi);

	int ret;



	dev_dbg(dev, "Runtime resume\n");



	ret = regulator_enable(trf->regulator);

	if (ret) {

		dev_err(dev, "%s - Can't enable VIN: %d\n", __func__, ret);

		return ret;

	}



	usleep_range(5000, 6000);



	gpio_set_value(trf->en2_gpio, 1);

	usleep_range(1000, 2000);

	gpio_set_value(trf->en_gpio, 1);



	usleep_range(20000, 21000);



	ret = trf7970a_init(trf);

	if (ret) {

		dev_err(dev, "%s - Can't initialize: %d\n", __func__, ret);

		return ret;

	}



	pm_runtime_mark_last_busy(dev);



	return 0;

}

#endif



static const struct dev_pm_ops trf7970a_pm_ops = {

	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,

			trf7970a_pm_runtime_resume, NULL)

};



static const struct spi_device_id trf7970a_id_table[] = {

	{ "trf7970a", TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA },

	{ }
@@ -1410,6 +1457,7 @@ static struct spi_driver trf7970a_spi_driver = { 
	.driver		= {

		.name	= "trf7970a",

		.owner	= THIS_MODULE,

		.pm	= &trf7970a_pm_ops,

	},

};