[PATCH] Make EN2 pin optional in the TRF7970A driver

[Heiko Schocher]

From: Guan Ben <ben.g...@cn.bosch.com>

Make the EN2 pin optional. This is useful for boards,
which have this pin fix wired, for example to ground.

Signed-off-by: Guan Ben <ben.g...@cn.bosch.com>
Signed-off-by: Mark Jonas <mark.jo...@de.bosch.com>
Signed-off-by: Heiko Schocher <h...@denx.de>

---

 .../devicetree/bindings/net/nfc/trf7970a.txt       |  4 ++--
 drivers/nfc/trf7970a.c                             | 26 ++++++++++++----------
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt 
b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
index 32b35a0..5889a3d 100644
--- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
+++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
@@ -5,8 +5,8 @@ Required properties:
 - spi-max-frequency: Maximum SPI frequency (<= 2000000).
 - interrupt-parent: phandle of parent interrupt handler.
 - interrupts: A single interrupt specifier.
-- ti,enable-gpios: Two GPIO entries used for 'EN' and 'EN2' pins on the
-  TRF7970A.
+- ti,enable-gpios: One or two GPIO entries used for 'EN' and 'EN2' pins on the
+  TRF7970A. EN2 is optional.
 - vin-supply: Regulator for supply voltage to VIN pin
 
 Optional SoC Specific Properties:
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 26c9dbb..75079fb 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -1885,8 +1885,10 @@ static int trf7970a_power_up(struct trf7970a *trf)
        usleep_range(5000, 6000);
 
        if (!(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
-               gpio_set_value(trf->en2_gpio, 1);
-               usleep_range(1000, 2000);
+               if (gpio_is_valid(trf->en2_gpio)) {
+                       gpio_set_value(trf->en2_gpio, 1);
+                       usleep_range(1000, 2000);
+               }
        }
 
        gpio_set_value(trf->en_gpio, 1);
@@ -1914,7 +1916,8 @@ static int trf7970a_power_down(struct trf7970a *trf)
        }
 
        gpio_set_value(trf->en_gpio, 0);
-       gpio_set_value(trf->en2_gpio, 0);
+       if (gpio_is_valid(trf->en2_gpio))
+               gpio_set_value(trf->en2_gpio, 0);
 
        ret = regulator_disable(trf->regulator);
        if (ret)
@@ -2032,15 +2035,14 @@ static int trf7970a_probe(struct spi_device *spi)
 
        trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
        if (!gpio_is_valid(trf->en2_gpio)) {
-               dev_err(trf->dev, "No EN2 GPIO property\n");
-               return trf->en2_gpio;
-       }
-
-       ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
-                       GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN2");
-       if (ret) {
-               dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
-               return ret;
+               dev_info(trf->dev, "No EN2 GPIO property\n");
+       } else {
+               ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
+                               GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN2");
+               if (ret) {
+                       dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
+                       return ret;
+               }
        }
 
        if (of_property_read_bool(np, "en2-rf-quirk"))
-- 
2.7.4