Am 2014-09-25 07:55, schrieb Shawn Guo:

On Tue, Sep 23, 2014 at 07:37:55PM +0200, Stefan Agner wrote:

quoted

diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
new file mode 100644
index 0000000..6649a13
--- /dev/null
+++ b/drivers/gpio/gpio-vf610.c

@@ -0,0 +1,284 @@
+/*
+ * vf610 GPIO support through PORT and GPIO module
+ *
+ * Copyright (c) 2014 Toradex AG.
+ *
+ * Author: Stefan Agner <stefan@agner.ch>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/bitops.h>
+#include <linux/gpio.h>

You might want to have the headers sort alphabetically.

quoted

+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/module.h>
+#include <asm-generic/bug.h>

Why do we need this header?

quoted

+
+

One new line is enough.

quoted

+#define VF610_GPIO_PER_PORT		32
+
+struct vf610_gpio_port {
+	struct gpio_chip gc;
+	void __iomem *base;
+	void __iomem *gpio_base;
+	u8 irqc[VF610_GPIO_PER_PORT];
+};
+
+#define GPIO_PDOR		0x00
+#define GPIO_PSOR		0x04
+#define GPIO_PCOR		0x08
+#define GPIO_PTOR		0x0c
+#define GPIO_PDIR		0x10
+
+#define PORT_PCR(n)		(n * 0x4)

s/n/(n)

...

quoted

+static int vf610_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct vf610_gpio_port *port;
+	struct resource *iores;
+	struct gpio_chip *gc;
+	int irq, ret;
+
+	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	port->base = devm_ioremap_resource(dev, iores);
+	if (IS_ERR(port->base))
+		return PTR_ERR(port->base);
+
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	port->gpio_base = devm_ioremap_resource(dev, iores);
+	if (IS_ERR(port->gpio_base))
+		return PTR_ERR(port->gpio_base);
+
+	irq = irq_of_parse_and_map(pdev->dev.of_node, 0);

Why not platform_get_irq()?

I thought we need that mapping, but this is done dynamically when using
gpiochip_irqchip_add.

quoted

+	if (irq == NO_IRQ)
+		return -ENODEV;

Instead of using NO_IRQ, we should check if irq is a negative value and
propagate the value as the return, something like:

	if (irq < 0)
		return irq;

Agreed on everything, will fix that.

quoted

+
+	gc = &port->gc;
+	gc->of_node = np;
+	gc->dev = dev;
+	gc->label = "vf610-gpio",
+	gc->ngpio = VF610_GPIO_PER_PORT,
+	gc->base = of_alias_get_id(np, "gpio") * VF610_GPIO_PER_PORT;
+
+	gc->request = vf610_gpio_request,
+	gc->free = vf610_gpio_free,
+	gc->direction_input = vf610_gpio_direction_input,
+	gc->get = vf610_gpio_get,
+	gc->direction_output = vf610_gpio_direction_output,
+	gc->set = vf610_gpio_set,
+
+	ret = gpiochip_add(gc);
+	if (ret < 0)
+		return ret;
+
+	/* Clear the interrupt status register for all GPIO's */
+	vf610_gpio_writel(~0, port->base + PORT_ISFR);
+
+	ret = gpiochip_irqchip_add(gc, &vf610_gpio_irq_chip, 0,
+				   handle_simple_irq, IRQ_TYPE_NONE);
+	if (ret) {
+		dev_err(dev, "failed to add irqchip\n");
+		gpiochip_remove(gc);
+		return ret;
+	}
+	gpiochip_set_chained_irqchip(gc, &vf610_gpio_irq_chip, irq,
+				     vf610_gpio_irq_handler);
+
+	return 0;
+}
+
+static struct platform_driver vf610_gpio_driver = {
+	.driver		= {
+		.name	= "gpio-vf610",
+		.owner	= THIS_MODULE,
+		.of_match_table = vf610_gpio_dt_ids,
+	},
+	.probe		= vf610_gpio_probe,
+};
+
+static int __init gpio_vf610_init(void)
+{
+	return platform_driver_register(&vf610_gpio_driver);
+}
+subsys_initcall(gpio_vf610_init);
+
+MODULE_AUTHOR("Stefan Agner [off-list ref]");
+MODULE_DESCRIPTION("Freescale VF610 GPIO");
+MODULE_LICENSE("GPL v2");
--
2.1.0