[PATCH 9/9] gpio: Added timbgpio

[PATCH 9/9] gpio: Added timbgpio

[Richard Röjfors]

Supplied is a GPIO driver for the Timberdale FPGA found on the
Intel Atom board Russellville.

Signed-off-by: Richard Röjfors <richard.rojfors.ext@mocean-labs.com>
---
Index: linux-2.6.30-rc7/drivers/gpio/timbgpio.c
===================================================================
--- linux-2.6.30-rc7/drivers/gpio/timbgpio.c	(revision 0)
+++ linux-2.6.30-rc7/drivers/gpio/timbgpio.c	(revision 892)
@@ -0,0 +1,247 @@
+/*
+ * timbgpio.c timberdale FPGA GPIO driver
+ * Copyright (c) 2009 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* Supports:
+ * Timberdale FPGA GPIO
+ */
+
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+
+#define DRIVER_NAME "timb-gpio"
+
+#define TIMB_NR_GPIOS		16
+
+#define TGPIOVAL		0
+#define TGPIODIR		0x04
+#define TGPIOINT		0x08
+#define TGPIOINT_STATUS		0x0c
+#define TGPIOINT_PENDING	0x10
+#define TGPIOINT_CLR		0x14
+#define TGPIOFLK		0x18
+#define TGPIOLVL		0x1c
+
+struct timbgpio {
+	void __iomem		*membase;
+	struct mutex		lock; /* mutual exclusion */
+	struct pci_dev		*pdev;
+	struct gpio_chip	gpio;
+};
+
+static u32 timbgpio_configure(struct gpio_chip *gpio, unsigned nr,
+						unsigned off, unsigned val)
+{
+	struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
+
+	u32 config, oldconfig, wconfig;
+
+	mutex_lock(&tgpio->lock);
+	config = ioread32(tgpio->membase + off);
+	oldconfig = config;
+
+	if (val)
+		config |= (1 << nr);
+	else
+		config &= ~(1 << nr);
+
+	iowrite32(config, tgpio->membase + off);
+	wconfig = ioread32(tgpio->membase + off);
+	mutex_unlock(&tgpio->lock);
+
+	return oldconfig;
+}
+
+static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
+{
+	timbgpio_configure(gpio, nr, TGPIODIR, 1);
+	return 0;
+}
+
+static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
+{
+	struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
+	u32 value;
+
+	value = ioread32(tgpio->membase + TGPIOVAL);
+	return (value & (1 << nr)) ? 1 : 0;
+}
+
+static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
+						unsigned nr, int val)
+{
+	timbgpio_configure(gpio, nr, TGPIODIR, 0);
+	return 0;
+}
+
+
+
+static void timbgpio_gpio_set(struct gpio_chip *gpio,
+				unsigned nr, int val)
+{
+	timbgpio_configure(gpio, nr, TGPIOVAL, val);
+}
+
+static irqreturn_t timbgpio_handleinterrupt(int irq, void *devid)
+{
+	struct timbgpio *tgpio = (struct timbgpio *)devid;
+
+	iowrite32(0xffffffff, tgpio->membase + TGPIOINT_CLR);
+
+	return IRQ_HANDLED;
+}
+
+static int timbgpio_probe(struct platform_device *dev)
+{
+	int err, irq;
+	struct gpio_chip *gc;
+	struct timbgpio *tgpio;
+	struct resource *iomem;
+
+	iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!iomem) {
+		err = -EINVAL;
+		goto err_mem;
+	}
+
+	tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL);
+	if (!tgpio) {
+		err = -EINVAL;
+		goto err_mem;
+	}
+
+	mutex_init(&tgpio->lock);
+
+	if (!request_mem_region(iomem->start, resource_size(iomem),
+		DRIVER_NAME)) {
+		err = -EBUSY;
+		goto err_request;
+	}
+
+	tgpio->membase = ioremap(iomem->start, resource_size(iomem));
+	if (!tgpio->membase) {
+		err = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	gc = &tgpio->gpio;
+
+	gc->label = DRIVER_NAME;
+	gc->owner = THIS_MODULE;
+	gc->direction_input = timbgpio_gpio_direction_input;
+	gc->get = timbgpio_gpio_get;
+	gc->direction_output = timbgpio_gpio_direction_output;
+	gc->set = timbgpio_gpio_set;
+	gc->dbg_show = NULL;
+	gc->base = 0;
+	gc->ngpio = TIMB_NR_GPIOS;
+	gc->can_sleep = 0;
+
+	err = gpiochip_add(gc);
+	if (err)
+		goto err_chipadd;
+
+	platform_set_drvdata(dev, tgpio);
+
+	/* register interrupt */
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0)
+		goto err_get_irq;
+
+	/* clear pending interrupts */
+	iowrite32(0xffffffff, tgpio->membase + TGPIOINT_CLR);
+	iowrite32(0x0, tgpio->membase + TGPIOINT);
+
+	/* request IRQ */
+	err = request_irq(irq, timbgpio_handleinterrupt, IRQF_SHARED,
+		DRIVER_NAME, tgpio);
+	if (err) {
+		printk(KERN_ERR DRIVER_NAME": Failed to request IRQ\n");
+		goto err_get_irq;
+	}
+
+	return err;
+
+err_get_irq:
+	err = gpiochip_remove(&tgpio->gpio);
+	if (err)
+		printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n");
+err_chipadd:
+	iounmap(tgpio->membase);
+err_ioremap:
+	release_mem_region(iomem->start, resource_size(iomem));
+err_request:
+	kfree(tgpio);
+err_mem:
+	printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err);
+
+	return err;
+}
+
+static int timbgpio_remove(struct platform_device *dev)
+{
+	int err;
+	struct timbgpio *tgpio = platform_get_drvdata(dev);
+	struct resource *iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
+
+	/* disable interrupts */
+	iowrite32(0x0, tgpio->membase + TGPIOINT);
+
+	free_irq(platform_get_irq(dev, 0), tgpio);
+	err = gpiochip_remove(&tgpio->gpio);
+	if (err)
+		printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n");
+
+	iounmap(tgpio->membase);
+	release_mem_region(iomem->start, resource_size(iomem));
+	kfree(tgpio);
+
+	return 0;
+}
+
+static struct platform_driver timbgpio_platform_driver = {
+	.driver = {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= timbgpio_probe,
+	.remove		= timbgpio_remove,
+};
+
+/*--------------------------------------------------------------------------*/
+
+static int __init timbgpio_init(void)
+{
+	return platform_driver_register(&timbgpio_platform_driver);
+}
+
+static void __exit timbgpio_exit(void)
+{
+	platform_driver_unregister(&timbgpio_platform_driver);
+}
+
+module_init(timbgpio_init);
+module_exit(timbgpio_exit);
+
+MODULE_DESCRIPTION("Timberdale GPIO driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Mocean Laboratories");
+MODULE_ALIAS("platform:"DRIVER_NAME);
+
Index: linux-2.6.30-rc7/drivers/gpio/Kconfig
===================================================================
--- linux-2.6.30-rc7/drivers/gpio/Kconfig	(revision 861)
+++ linux-2.6.30-rc7/drivers/gpio/Kconfig	(working copy)
@@ -161,6 +161,12 @@

 	  If unsure, say N.

+config GPIO_TIMBERDALE
+	tristate "Support for timberdale GPIO"
+	depends on MFD_TIMBERDALE && GPIOLIB
+	---help---
+	Add support for GPIO usage of some pins of the timberdale FPGA.
+
 comment "SPI GPIO expanders:"

 config GPIO_MAX7301

Index: linux-2.6.30-rc7/drivers/gpio/Makefile
===================================================================
--- linux-2.6.30-rc7/drivers/gpio/Makefile	(revision 861)
+++ linux-2.6.30-rc7/drivers/gpio/Makefile	(working copy)
@@ -12,5 +12,6 @@
 obj-$(CONFIG_GPIO_TWL4030)	+= twl4030-gpio.o
 obj-$(CONFIG_GPIO_XILINX)	+= xilinx_gpio.o
 obj-$(CONFIG_GPIO_BT8XX)	+= bt8xxgpio.o
+obj-$(CONFIG_GPIO_TIMBERDALE)	+= timbgpio.o
 obj-$(CONFIG_GPIO_MC33880)	+= mc33880.o