wr-nic-gpio: filled, only I/O is missing now

kernel/wr-nic-gpio.c

+/*
+ * Copyright (C) 2012 CERN (www.cern.ch)
+ * Author: Alessandro Rubini <rubini@gnudd.com>
+ *
+ * Released according to the GNU GPL, version 2 or any later version.
+ *
+ * This work is part of the White Rabbit project, a research effort led
+ * by CERN, the European Institute for Nuclear Research.
+ */
 #include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/gpio.h>
 #include <linux/fmc.h>
 #include "spec.h"
 #include "wr-nic.h"
 
+static inline struct fmc_device *gc_to_fmc(struct gpio_chip *gc)
+{
+	struct device *dev = gc->dev;
+	return container_of(dev, struct fmc_device, dev);
+}
+
+static int wrn_gpio_input(struct gpio_chip *chip, unsigned offset)
+{
+	//struct fmc_device *fmc = gc_to_fmc(chip);
+	//struct wrn_drvdata *dd = fmc_get_drvdata(fmc);
+
+	//fmc_writel(fmc, ...); /*  FIXME  */
+	return -EAGAIN;
+}
+
+static int wrn_gpio_output(struct gpio_chip *chip, unsigned offset, int value)
+{
+	return -EAGAIN;
+}
+
+int wrn_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	return -EAGAIN;
+}
+
+void wrn_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	return;
+}
+
+static const char *wrn_gpio_names[] = {
+	"dire", "fare", "baciare", "lettera", "testamento"
+};
+
+static struct gpio_chip wrn_gpio_template = {
+	.label = "wr-nic",
+	.owner = THIS_MODULE,
+	/* FIXME: request, free, for multi-function operation */
+	.direction_input = wrn_gpio_input,
+	.direction_output = wrn_gpio_output,
+	.get = wrn_gpio_get,
+	.set = wrn_gpio_set,
+	.base = -1, /* request dynamic */
+	.ngpio = 5,
+	.names = wrn_gpio_names,
+};
+
 int wrn_gpio_init(struct fmc_device *fmc)
 {
+	struct wrn_drvdata *dd = fmc_get_drvdata(fmc);
+	struct gpio_chip *gc;
+	int ret;
+
+	gc = devm_kzalloc(&fmc->dev, sizeof(*gc), GFP_KERNEL);
+	if (!gc)
+		return -ENOMEM;
+	*gc = wrn_gpio_template;
+	gc->dev = &fmc->dev;
+
+	ret = gpiochip_add(gc);
+	if (ret < 0)
+		goto out_free;
+	dd->gc = gc;
+
+	/* FIXME: program the DAC for each port (sysfs attributes?) */
 	return 0;
+
+out_free:
+	kfree(gc);
+	return ret;
 }
 
 void wrn_gpio_exit(struct fmc_device *fmc)
 {
+	int ret;
+
+	struct wrn_drvdata *dd = fmc_get_drvdata(fmc);
+	struct gpio_chip *gc = dd->gc;
+	ret = gpiochip_remove(gc);
+	if (ret)
+		dev_err(fmc->hwdev, "DANGER %i! gpio chip can't be removed\n",
+			ret);
+	return;
 }