spi: sc18is602: Add reset control via gpio pin.

This sc18is602 has a reset pin that may need to be deasserted.
Add optional binding to specifiy the reset pin via a gpio and deassert
during probe.

Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-sc18is602.c b/drivers/spi/spi-sc18is602.c
index 36af4d48a700520bc3bdea7aaf987b1cf9dff057..5666b5d20b874625143610edf3e7e6c0922a75a2 100644 (file)
--- a/drivers/spi/spi-sc18is602.c
+++ b/drivers/spi/spi-sc18is602.c
@@ -23,6 +23,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
 #include <linux/platform_data/sc18is602.h>
+#include <linux/gpio/consumer.h>
 
 enum chips { sc18is602, sc18is602b, sc18is603 };
 
@@ -50,6 +51,8 @@ struct sc18is602 {
        u8                      buffer[SC18IS602_BUFSIZ + 1];
        int                     tlen;   /* Data queued for tx in buffer */
        int                     rindex; /* Receive data index in buffer */
+
+       struct gpio_desc        *reset;
 };
 
 static int sc18is602_wait_ready(struct sc18is602 *hw, int len)
@@ -257,6 +260,12 @@ static int sc18is602_probe(struct i2c_client *client,
        hw = spi_master_get_devdata(master);
        i2c_set_clientdata(client, hw);
 
+       /* assert reset and then release */
+       hw->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+       if (IS_ERR(hw->reset))
+               return PTR_ERR(hw->reset);
+       gpiod_set_value(hw->reset, 0);
+
        hw->master = master;
        hw->client = client;
        hw->dev = dev;