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: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 0a46348..26e7449 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -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 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 @@
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);
+ trf->state = TRF7970A_ST_IDLE;
- /* 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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
.driver = {
.name = "trf7970a",
.owner = THIS_MODULE,
+ .pm = &trf7970a_pm_ops,
},
};