[PATCH v3] gpio: add Intel Moorestown Platform Langwell chip gpio driver

Alek Du
2009-07-03T13:12:28Z

Changes from v2:
1. Add missed MODULE_DEVICE_TABLE

Changes from v1:
1. driver name changed from lnw.c ==> langwell_gpio.c
2. removed hard coded driver data, now we get it from PCI bar1 (platform init code fills it)
3. removed alternative function setting code, it should be called in platform init part.
4. misc. style clean

>From 8eaad3aac8cffda193adcfc4b9fcbb7c461fd4b9 Mon Sep 17 00:00:00 2001
From: Alek Du <alek.du@intel.com>
Date: Tue, 30 Jun 2009 12:13:27 +0800
Subject: [PATCH] gpio: add Intel Moorestown Platform Langwell chip gpio driver

The Langwell chip is the IO hub for Intel Moorestown platform which has a
64-pin gpio block device inside. It is exposed as a dedicated PCI device.
We use it to control outside peripheral as well as to do IRQ demuxing. The
gpio block uses MSI to send level type interrupt to IOAPIC.

Signed-off-by: Alek Du <alek.du@intel.com>
CC: David Brownell <david-b@pacbell.net>
---
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/langwell_gpio.c | 318 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 325 insertions(+), 0 deletions(-)
create mode 100644 drivers/gpio/langwell_gpio.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 3582c39..c9675de 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -167,6 +167,12 @@ config GPIO_BT8XX

If unsure, say N.

+config GPIO_LANGWELL
+ tristate "Intel Moorestown Platform Langwell GPIO support"
+ depends on PCI
+ help
+ Say Y here to support Intel Moorestown platform GPIO.
+
comment "SPI GPIO expanders:"

config GPIO_MAX7301
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index ef90203..a267d5d 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_GPIO_PL061) += pl061.o
obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o
obj-$(CONFIG_GPIO_XILINX) += xilinx_gpio.o
obj-$(CONFIG_GPIO_BT8XX) += bt8xxgpio.o
+obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o
diff --git a/drivers/gpio/langwell_gpio.c b/drivers/gpio/langwell_gpio.c
new file mode 100644
index 0000000..e338baa
--- /dev/null
+++ b/drivers/gpio/langwell_gpio.c
@@ -0,0 +1,318 @@
+/* langwell_gpio.c Moorestown platform Langwell chip GPIO driver
+ * Copyright (c) 2008 - 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:
+ * Moorestown platform Langwell chip.
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/stddef.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+
+struct lnw_gpio_register {
+ u32 GPLR[2];
+ u32 GPDR[2];
+ u32 GPSR[2];
+ u32 GPCR[2];
+ u32 GRER[2];
+ u32 GFER[2];
+ u32 GEDR[2];
+};
+
+struct lnw_gpio {
+ struct gpio_chip chip;
+ struct lnw_gpio_register *reg_base;
+ spinlock_t lock;
+ unsigned irq_base;
+};
+
+static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ u8 reg = offset / 32;
+ void __iomem *gplr;
+
+ gplr = (void __iomem *)(&lnw->reg_base->GPLR[reg]);
+ return readl(gplr) & BIT(offset % 32);
+}
+
+static void lnw_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ u8 reg = offset / 32;
+ void __iomem *gpsr, *gpcr;
+
+ if (value) {
+ gpsr = (void __iomem *)(&lnw->reg_base->GPSR[reg]);
+ writel(BIT(offset % 32), gpsr);
+ } else {
+ gpcr = (void __iomem *)(&lnw->reg_base->GPCR[reg]);
+ writel(BIT(offset % 32), gpcr);
+ }
+}
+
+static int lnw_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ u8 reg = offset / 32;
+ u32 value;
+ unsigned long flags;
+ void __iomem *gpdr;
+
+ gpdr = (void __iomem *)(&lnw->reg_base->GPDR[reg]);
+ spin_lock_irqsave(&lnw->lock, flags);
+ value = readl(gpdr);
+ value &= ~BIT(offset % 32);
+ writel(value, gpdr);
+ spin_unlock_irqrestore(&lnw->lock, flags);
+ return 0;
+}
+
+static int lnw_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ u8 reg = offset / 32;
+ unsigned long flags;
+ void __iomem *gpdr;
+
+ lnw_gpio_set(chip, offset, value);
+ gpdr = (void __iomem *)(&lnw->reg_base->GPDR[reg]);
+ spin_lock_irqsave(&lnw->lock, flags);
+ value = readl(gpdr);
+ value |= BIT(offset % 32);;
+ writel(value, gpdr);
+ spin_unlock_irqrestore(&lnw->lock, flags);
+ return 0;
+}
+
+static int lnw_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
+ return lnw->irq_base + offset;
+}
+
+static int lnw_irq_type(unsigned irq, unsigned type)
+{
+ struct lnw_gpio *lnw = get_irq_chip_data(irq);
+ u32 gpio = irq - lnw->irq_base;
+ u8 reg = gpio / 32;
+ unsigned long flags;
+ u32 value;
+ void __iomem *grer = (void __iomem *)(&lnw->reg_base->GRER[reg]);
+ void __iomem *gfer = (void __iomem *)(&lnw->reg_base->GFER[reg]);
+
+ if (gpio < 0 || gpio > lnw->chip.ngpio)
+ return -EINVAL;
+ spin_lock_irqsave(&lnw->lock, flags);
+ if (type & IRQ_TYPE_EDGE_RISING)
+ value = readl(grer) | BIT(gpio % 32);
+ else
+ value = readl(grer) & (~BIT(gpio % 32));
+ writel(value, grer);
+
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ value = readl(gfer) | BIT(gpio % 32);
+ else
+ value = readl(gfer) & (~BIT(gpio % 32));
+ writel(value, gfer);
+ spin_unlock_irqrestore(&lnw->lock, flags);
+
+ return 0;
+};
+
+static void lnw_irq_unmask(unsigned irq)
+{
+ struct lnw_gpio *lnw = get_irq_chip_data(irq);
+ u32 gpio = irq - lnw->irq_base;
+ u8 reg = gpio / 32;
+ void __iomem *gedr;
+
+ gedr = (void __iomem *)(&lnw->reg_base->GEDR[reg]);
+ writel(BIT(gpio % 32), gedr);
+};
+
+static struct irq_chip lnw_irqchip = {
+ .name = "LNW-GPIO",
+ .unmask = lnw_irq_unmask,
+ .set_type = lnw_irq_type,
+};
+
+static struct pci_device_id lnw_gpio_ids[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f) },
+ { 0, }
+};
+MODULE_DEVICE_TABLE(pci, lnw_gpio_ids);
+
+static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+ struct lnw_gpio *lnw = (struct lnw_gpio *)get_irq_data(irq);
+ u32 reg, gpio;
+ void __iomem *gedr;
+ u32 gedr_v;
+
+ /* check GPIO controller to check which pin triggered the interrupt */
+ for (reg = 0; reg < lnw->chip.ngpio / 32; reg++) {
+ gedr = (void __iomem *)(&lnw->reg_base->GEDR[reg]);
+ gedr_v = readl(gedr);
+ if (!gedr_v)
+ continue;
+ for (gpio = reg*32; gpio < reg*32+32; gpio++) {
+ gedr_v = readl(gedr);
+ if (gedr_v & BIT(gpio % 32)) {
+ pr_debug("pin %d triggered\n", gpio);
+ generic_handle_irq(lnw->irq_base + gpio);
+ }
+ }
+ /* clear the edge detect status bit */
+ writel(gedr_v, gedr);
+ }
+ desc->chip->eoi(irq);
+}
+
+static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ void *base;
+ int i;
+ resource_size_t start, len;
+ struct lnw_gpio *lnw;
+ u32 irq_base;
+ u32 gpio_base;
+ int retval = 0;
+
+ retval = pci_enable_device(pdev);
+ if (retval)
+ goto done;
+
+ retval = pci_request_regions(pdev, "langwell_gpio");
+ if (retval) {
+ dev_err(&pdev->dev, "error requesting resources\n");
+ goto err2;
+ }
+ /* get the irq_base from bar1 */
+ start = pci_resource_start(pdev, 1);
+ len = pci_resource_len(pdev, 1);
+ base = ioremap_nocache(start, len);
+ if (!base) {
+ dev_err(&pdev->dev, "error mapping bar1\n");
+ goto err3;
+ }
+ irq_base = *(u32 *)base;
+ gpio_base = *((u32 *)base + 1);
+ /* release the IO mapping, since we already get the info from bar1 */
+ iounmap(base);
+ /* get the register base from bar0 */
+ start = pci_resource_start(pdev, 0);
+ len = pci_resource_len(pdev, 0);
+ base = ioremap_nocache(start, len);
+ if (!base) {
+ dev_err(&pdev->dev, "error mapping bar0\n");
+ retval = -EFAULT;
+ goto err3;
+ }
+
+ lnw = kzalloc(sizeof(struct lnw_gpio), GFP_KERNEL);
+ if (!lnw) {
+ dev_err(&pdev->dev, "can't allocate langwell_gpio chip data\n");
+ retval = -ENOMEM;
+ goto err4;
+ }
+ lnw->reg_base = base;
+ lnw->irq_base = irq_base;
+ lnw->chip.label = dev_name(&pdev->dev);
+ lnw->chip.direction_input = lnw_gpio_direction_input;
+ lnw->chip.direction_output = lnw_gpio_direction_output;
+ lnw->chip.get = lnw_gpio_get;
+ lnw->chip.set = lnw_gpio_set;
+ lnw->chip.to_irq = lnw_gpio_to_irq;
+ lnw->chip.base = gpio_base;
+ lnw->chip.ngpio = 64;
+ lnw->chip.can_sleep = 0;
+ pci_set_drvdata(pdev, lnw);
+ retval = gpiochip_add(&lnw->chip);
+ if (retval) {
+ dev_err(&pdev->dev, "langwell gpiochip_add error %d\n", retval);
+ goto err5;
+ }
+ set_irq_data(pdev->irq, lnw);
+ set_irq_chained_handler(pdev->irq, lnw_irq_handler);
+ for (i = 0; i < lnw->chip.ngpio; i++) {
+ set_irq_chip_and_handler_name(i + lnw->irq_base, &lnw_irqchip,
+ handle_simple_irq, "demux");
+ set_irq_chip_data(i + lnw->irq_base, lnw);
+ }
+
+ spin_lock_init(&lnw->lock);
+ goto done;
+err5:
+ kfree(lnw);
+err4:
+ iounmap(base);
+err3:
+ pci_release_regions(pdev);
+err2:
+ pci_disable_device(pdev);
+done:
+ return retval;
+}
+
+static void __devexit lnw_gpio_remove(struct pci_dev *pdev)
+{
+ struct lnw_gpio *lnw = (struct lnw_gpio *)pci_get_drvdata(pdev);
+
+ if (gpiochip_remove(&lnw->chip)) {
+ dev_err(&pdev->dev, "langwell gpio driver remove error\n");
+ return;
+ }
+ pci_disable_device(pdev);
+ set_irq_chained_handler(pdev->irq, NULL);
+ pci_release_regions(pdev);
+ iounmap(lnw->reg_base);
+ pci_set_drvdata(pdev, NULL);
+ kfree(lnw);
+}
+
+static struct pci_driver lnw_gpio_driver = {
+ .name = "langwell_gpio",
+ .id_table = lnw_gpio_ids,
+ .probe = lnw_gpio_probe,
+ .remove = lnw_gpio_remove,
+};
+
+static int __init lnw_gpio_init(void)
+{
+ return pci_register_driver(&lnw_gpio_driver);
+}
+
+static void __exit lnw_gpio_exit(void)
+{
+ pci_unregister_driver(&lnw_gpio_driver);
+}
+
+MODULE_AUTHOR("Alek Du <alek.du@intel.com>");
+MODULE_DESCRIPTION("Intel Moorestown Platform Langwell chip GPIO driver");
+MODULE_LICENSE("GPL v2");
+
+module_init(lnw_gpio_init);
+module_exit(lnw_gpio_exit);
--
1.6.0.4