[U-Boot] [PATCH] i2c: muxes: pca954x: Add support for GPIO reset line

[Moritz Fischer]

This commit adds support for GPIO reset lines matching the
common linux "reset-gpios" devicetree binding.

Signed-off-by: Moritz Fischer <moritz.fischer at ettus.com>
Cc: Heiko Schocher <hs at denx.de>
Cc: Stefan Roese <sr at denx.de>
Cc: Marek Behún <marek.behun at nic.cz>
Cc: Simon Glass <sjg at chromium.org>
Cc: Michal Simek <monstr at monstr.eu>

---
 drivers/i2c/muxes/pca954x.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
index 383f72f552..dd28ff057b 100644
--- a/drivers/i2c/muxes/pca954x.c
+++ b/drivers/i2c/muxes/pca954x.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2015 - 2016 Xilinx, Inc.
+ * Copyright (C) 2017 National Instruments Corp
  * Written by Michal Simek
  *
  * SPDX-License-Identifier:	GPL-2.0+
@@ -9,7 +10,10 @@
 #include <dm.h>
 #include <errno.h>
 #include <i2c.h>
-#include <asm/gpio.h>
+
+#if CONFIG_DM_GPIO
+# include <asm-generic/gpio.h>
+#endif /* CONFIG_DM_GPIO */
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -30,6 +34,9 @@ struct chip_desc {
 struct pca954x_priv {
 	u32 addr; /* I2C mux address */
 	u32 width; /* I2C mux width - number of busses */
+#ifdef CONFIG_DM_GPIO
+	struct gpio_desc gpio_mux_reset;
+#endif /* CONFIG_DM_GPIO */
 };
 
 static const struct chip_desc chips[] = {
@@ -105,10 +112,45 @@ static int pca954x_ofdata_to_platdata(struct udevice *dev)
 	return 0;
 }
 
+static int pca954x_probe(struct udevice *dev)
+{
+#ifdef CONFIG_DM_GPIO
+	struct pca954x_priv *priv = dev_get_priv(dev);
+	int err;
+
+	err = gpio_request_by_name(dev, "reset-gpios", 0,
+			&priv->gpio_mux_reset, GPIOD_IS_OUT);
+
+	/* it's optional so only bail if we get a real error */
+	if (err && (err != -ENOENT))
+		return err;
+
+	/* dm will take care of polarity */
+	if (dm_gpio_is_valid(&priv->gpio_mux_reset))
+		dm_gpio_set_value(&priv->gpio_mux_reset, 0);
+
+#endif /* CONFIG_DM_GPIO */
+	return 0;
+}
+
+static int pca954x_remove(struct udevice *dev)
+{
+#ifdef CONFIG_DM_GPIO
+	struct pca954x_priv *priv = dev_get_priv(dev);
+
+	if (dm_gpio_is_valid(&priv->gpio_mux_reset))
+		dm_gpio_free(dev, &priv->gpio_mux_reset);
+
+#endif /* CONFIG_DM_GPIO */
+	return 0;
+}
+
 U_BOOT_DRIVER(pca954x) = {
 	.name = "pca954x",
 	.id = UCLASS_I2C_MUX,
 	.of_match = pca954x_ids,
+	.probe = pca954x_probe,
+	.remove = pca954x_remove,
 	.ops = &pca954x_ops,
 	.ofdata_to_platdata = pca954x_ofdata_to_platdata,
 	.priv_auto_alloc_size = sizeof(struct pca954x_priv),
-- 
2.14.1