[PATCH linux dev-5.3 1/2] fsi: aspeed: Configure optional GPIOs

[Joel Stanley]

On Tacoma the enable and mux GPIOs allow the BMC to enable FSI and
control if the clock and data should come from the BMC, or from the
debug connector.

Configure these as optional GPIOs which will fail without error for
systems that do not have these GPIOs in their device tree.

Signed-off-by: Joel Stanley <joel at jms.id.au>
---
 drivers/fsi/fsi-master-aspeed.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
index 6496d2972944..2048e38e7200 100644
--- a/drivers/fsi/fsi-master-aspeed.c
+++ b/drivers/fsi/fsi-master-aspeed.c
@@ -14,6 +14,7 @@
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/iopoll.h>
+#include <linux/gpio/consumer.h>
 
 #include "fsi-master.h"
 
@@ -85,6 +86,9 @@ struct fsi_master_aspeed {
 	void __iomem		*base;
 	struct clk		*clk;
 
+	struct gpio_desc	*gpio_enable;
+	struct gpio_desc	*gpio_mux;
+
 	struct dentry		*debugfs_dir;
 	struct fsi_master_aspeed_debugfs_entry debugfs[FSI_NUM_DEBUGFS_ENTRIES];
 };
@@ -471,6 +475,30 @@ DEFINE_DEBUGFS_ATTRIBUTE(fsi_master_aspeed_debugfs_ops,
 			 fsi_master_aspeed_debugfs_get,
 			 fsi_master_aspeed_debugfs_set, "0x%08llx\n");
 
+static int aspeed_master_gpio_init(struct fsi_master_aspeed *master)
+{
+	struct device *dev = master->dev;
+	struct gpio_desc *gpio;
+
+	gpio = devm_gpiod_get_optional(dev, "fsi-enable", 0);
+	if (IS_ERR(gpio)) {
+		dev_err(dev, "failed to get fsi enable gpio\n");
+		return PTR_ERR(gpio);
+	}
+	master->gpio_enable = gpio;
+	gpiod_direction_output(master->gpio_enable, 1);
+
+	gpio = devm_gpiod_get_optional(dev, "fsi-mux", 0);
+	if (IS_ERR(gpio)) {
+		dev_err(dev, "failed to get fsi mux gpio\n");
+		return PTR_ERR(gpio);
+	}
+	master->gpio_mux = gpio;
+	gpiod_direction_output(master->gpio_mux, 1);
+
+	return 0;
+}
+
 static int fsi_master_aspeed_probe(struct platform_device *pdev)
 {
 	struct fsi_master_aspeed *aspeed;
@@ -540,6 +568,8 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(&pdev->dev, aspeed);
 
+	aspeed_master_gpio_init(aspeed);
+
 	aspeed_master_init(aspeed);
 
 	aspeed->debugfs_dir = debugfs_create_dir("fsi-master-aspeed", NULL);
-- 
2.23.0