--- /dev/null
+/*
+ * 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/platform_device.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/timb_gpio.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#define DRIVER_NAME "timb-gpio"
+
+#define TGPIOVAL 0x00
+#define TGPIODIR 0x04
+#define TGPIO_IER 0x08
+#define TGPIO_ISR 0x0c
+#define TGPIO_IPR 0x10
+#define TGPIO_ICR 0x14
+#define TGPIO_FLR 0x18
+#define TGPIO_LVR 0x1c
+#define TGPIO_VER 0x20
+#define TGPIO_BFLR 0x24
+
+struct timbgpio {
+ void __iomem *membase;
+ spinlock_t lock; /* mutual exclusion */
+ struct gpio_chip gpio;
+ int irq_base;
+ unsigned long last_ier;
+};
+
+static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
+ unsigned offset, bool enabled)
+{
+ struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
+ u32 reg;
+
+ spin_lock(&tgpio->lock);
+ reg = ioread32(tgpio->membase + offset);
+
+ if (enabled)
+ reg |= (1 << index);
+ else
+ reg &= ~(1 << index);
+
+ iowrite32(reg, tgpio->membase + offset);
+ spin_unlock(&tgpio->lock);
+
+ return 0;
+}
+
+static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
+{
+ return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
+}
+
+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)
+{
+ return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
+}
+
+static void timbgpio_gpio_set(struct gpio_chip *gpio,
+ unsigned nr, int val)
+{
+ timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
+}
+
+static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
+{
+ struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
+
+ if (tgpio->irq_base <= 0)
+ return -EINVAL;
+
+ return tgpio->irq_base + offset;
+}
+
+/*
+ * GPIO IRQ
+ */
+static void timbgpio_irq_disable(struct irq_data *d)
+{
+ struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
+ int offset = d->irq - tgpio->irq_base;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tgpio->lock, flags);
+ tgpio->last_ier &= ~(1UL << offset);
+ iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
+ spin_unlock_irqrestore(&tgpio->lock, flags);
+}
+
+static void timbgpio_irq_enable(struct irq_data *d)
+{
+ struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
+ int offset = d->irq - tgpio->irq_base;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tgpio->lock, flags);
+ tgpio->last_ier |= 1UL << offset;
+ iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
+ spin_unlock_irqrestore(&tgpio->lock, flags);
+}
+
+static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
+{
+ struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
+ int offset = d->irq - tgpio->irq_base;
+ unsigned long flags;
+ u32 lvr, flr, bflr = 0;
+ u32 ver;
+ int ret = 0;
+
+ if (offset < 0 || offset > tgpio->gpio.ngpio)
+ return -EINVAL;
+
+ ver = ioread32(tgpio->membase + TGPIO_VER);
+
+ spin_lock_irqsave(&tgpio->lock, flags);
+
+ lvr = ioread32(tgpio->membase + TGPIO_LVR);
+ flr = ioread32(tgpio->membase + TGPIO_FLR);
+ if (ver > 2)
+ bflr = ioread32(tgpio->membase + TGPIO_BFLR);
+
+ if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
+ bflr &= ~(1 << offset);
+ flr &= ~(1 << offset);
+ if (trigger & IRQ_TYPE_LEVEL_HIGH)
+ lvr |= 1 << offset;
+ else
+ lvr &= ~(1 << offset);
+ }
+
+ if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
+ if (ver < 3) {
+ ret = -EINVAL;
+ goto out;
+ } else {
+ flr |= 1 << offset;
+ bflr |= 1 << offset;
+ }
+ } else {
+ bflr &= ~(1 << offset);
+ flr |= 1 << offset;
+ if (trigger & IRQ_TYPE_EDGE_FALLING)
+ lvr &= ~(1 << offset);
+ else
+ lvr |= 1 << offset;
+ }
+
+ iowrite32(lvr, tgpio->membase + TGPIO_LVR);
+ iowrite32(flr, tgpio->membase + TGPIO_FLR);
+ if (ver > 2)
+ iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
+
+ iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
+
+out:
+ spin_unlock_irqrestore(&tgpio->lock, flags);
+ return ret;
+}
+
+static void timbgpio_irq(unsigned int irq, struct irq_desc *desc)
+{
+ struct timbgpio *tgpio = irq_get_handler_data(irq);
+ unsigned long ipr;
+ int offset;
+
+ desc->irq_data.chip->irq_ack(irq_get_irq_data(irq));
+ ipr = ioread32(tgpio->membase + TGPIO_IPR);
+ iowrite32(ipr, tgpio->membase + TGPIO_ICR);
+
+ /*
+ * Some versions of the hardware trash the IER register if more than
+ * one interrupt is received simultaneously.
+ */
+ iowrite32(0, tgpio->membase + TGPIO_IER);
+
+ for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
+ generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
+
+ iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
+}
+
+static struct irq_chip timbgpio_irqchip = {
+ .name = "GPIO",
+ .irq_enable = timbgpio_irq_enable,
+ .irq_disable = timbgpio_irq_disable,
+ .irq_set_type = timbgpio_irq_type,
+};
+
+static int timbgpio_probe(struct platform_device *pdev)
+{
+ int err, i;
+ struct device *dev = &pdev->dev;
+ struct gpio_chip *gc;
+ struct timbgpio *tgpio;
+ struct resource *iomem;
+ struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ int irq = platform_get_irq(pdev, 0);
+
+ if (!pdata || pdata->nr_pins > 32) {
+ dev_err(dev, "Invalid platform data\n");
+ return -EINVAL;
+ }
+
+ iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!iomem) {
+ dev_err(dev, "Unable to get resource\n");
+ return -EINVAL;
+ }
+
+ tgpio = devm_kzalloc(dev, sizeof(struct timbgpio), GFP_KERNEL);
+ if (!tgpio) {
+ dev_err(dev, "Memory alloc failed\n");
+ return -EINVAL;
+ }
+ tgpio->irq_base = pdata->irq_base;
+
+ spin_lock_init(&tgpio->lock);
+
+ if (!devm_request_mem_region(dev, iomem->start, resource_size(iomem),
+ DRIVER_NAME)) {
+ dev_err(dev, "Region already claimed\n");
+ return -EBUSY;
+ }
+
+ tgpio->membase = devm_ioremap(dev, iomem->start, resource_size(iomem));
+ if (!tgpio->membase) {
+ dev_err(dev, "Cannot ioremap\n");
+ return -ENOMEM;
+ }
+
+ gc = &tgpio->gpio;
+
+ gc->label = dev_name(&pdev->dev);
+ gc->owner = THIS_MODULE;
+ gc->dev = &pdev->dev;
+ 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->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
+ gc->dbg_show = NULL;
+ gc->base = pdata->gpio_base;
+ gc->ngpio = pdata->nr_pins;
+ gc->can_sleep = false;
+
+ err = gpiochip_add(gc);
+ if (err)
+ return err;
+
+ platform_set_drvdata(pdev, tgpio);
+
+ /* make sure to disable interrupts */
+ iowrite32(0x0, tgpio->membase + TGPIO_IER);
+
+ if (irq < 0 || tgpio->irq_base <= 0)
+ return 0;
+
+ for (i = 0; i < pdata->nr_pins; i++) {
+ irq_set_chip_and_handler(tgpio->irq_base + i,
+ &timbgpio_irqchip, handle_simple_irq);
+ irq_set_chip_data(tgpio->irq_base + i, tgpio);
+#ifdef CONFIG_ARM
+ set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE);
+#endif
+ }
+
+ irq_set_handler_data(irq, tgpio);
+ irq_set_chained_handler(irq, timbgpio_irq);
+
+ return 0;
+}
+
+static int timbgpio_remove(struct platform_device *pdev)
+{
+ struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct timbgpio *tgpio = platform_get_drvdata(pdev);
+ int irq = platform_get_irq(pdev, 0);
+
+ if (irq >= 0 && tgpio->irq_base > 0) {
+ int i;
+ for (i = 0; i < pdata->nr_pins; i++) {
+ irq_set_chip(tgpio->irq_base + i, NULL);
+ irq_set_chip_data(tgpio->irq_base + i, NULL);
+ }
+
+ irq_set_handler(irq, NULL);
+ irq_set_handler_data(irq, NULL);
+ }
+
+ gpiochip_remove(&tgpio->gpio);
+
+ return 0;
+}
+
+static struct platform_driver timbgpio_platform_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ },
+ .probe = timbgpio_probe,
+ .remove = timbgpio_remove,
+};
+
+/*--------------------------------------------------------------------------*/
+
+module_platform_driver(timbgpio_platform_driver);
+
+MODULE_DESCRIPTION("Timberdale GPIO driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Mocean Laboratories");
+MODULE_ALIAS("platform:"DRIVER_NAME);
+
Code Review / kvmfornfv.git / blobdiff