[PATCH 2/2] gpio: Add a driver for Sodaville GPIO controller

From: Sebastian Andrzej Siewior
Date: Wed Apr 27 2011 - 10:37:26 EST


From: Hans J. Koch <hjk@xxxxxxxxxxxxx>

Sodaville has GPIO controller behind the PCI bus. To my suprissed it is
not the same as on PXA.

The interrupt & gpio chip can be referenced from the device tree like
from any other driver. Unfortunately the driver which uses the gpio
interrupt has to use irq_of_parse_and_map() instead of
platform_get_irq(). The problem is that the platform device (which is
created from the device tree) is most likely created before the
interrupt chip is registered and therefore irq_of_parse_and_map() fails.

In theory the driver works as module. In reality most of the irq
functions are not exported to modules and it is possible that _this_
module is unloaded while the provided irqs are still in use.

Signed-off-by: Hans J. Koch <hjk@xxxxxxxxxxxxx>
[torbenh@xxxxxxxxxxxxx: make it work after the irq namespace cleanup,
add some device tree entries.]
Signed-off-by: Torben Hohn <torbenh@xxxxxxxxxxxxx>
[bigeasy@xxxxxxxxxxxxx: some refactoring, a little documentation]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
.../devicetree/bindings/gpio/sodaville.txt | 8 +
arch/x86/platform/ce4100/falconfalls.dts | 7 +-
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/sodaville_gpio.c | 421 ++++++++++++++++++++
5 files changed, 441 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/sodaville.txt
create mode 100644 drivers/gpio/sodaville_gpio.c

diff --git a/Documentation/devicetree/bindings/gpio/sodaville.txt b/Documentation/devicetree/bindings/gpio/sodaville.txt
new file mode 100644
index 0000000..6610cf3
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/sodaville.txt
@@ -0,0 +1,8 @@
+GPIO controller on CE4100 / Sodaville SoCs
+==========================================
+
+The bindings for CE4100's GPIO controller match the generic description
+which is covered by the gpio.txt file in this folder.
+
+The only additional property is the muxctl property which holds the
+value which is written into the MUXCNTL register.
diff --git a/arch/x86/platform/ce4100/falconfalls.dts b/arch/x86/platform/ce4100/falconfalls.dts
index e70be38..751a9ec 100644
--- a/arch/x86/platform/ce4100/falconfalls.dts
+++ b/arch/x86/platform/ce4100/falconfalls.dts
@@ -208,16 +208,19 @@
interrupts = <14 1>;
};

- gpio@b,1 {
+ pcigpio: gpio@b,1 {
+ #gpio-cells = <2>;
+ #interrupt-cells = <2>;
compatible = "pci8086,2e67.2",
"pci8086,2e67",
"pciclassff0000",
"pciclassff00";

- #gpio-cells = <2>;
reg = <0x15900 0x0 0x0 0x0 0x0>;
interrupts = <15 1>;
+ interrupt-controller;
gpio-controller;
+ muxctl = <0>;
};

i2c-controller@b,2 {
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d3b2953..2a665de 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -345,6 +345,12 @@ config GPIO_ML_IOH
Hub) which is for IVI(In-Vehicle Infotainment) use.
This driver can access the IOH's GPIO device.

+config GPIO_SODAVILLE
+ bool "Intel Sodaville GPIO support"
+ depends on PCI
+ help
+ Say Y here to support Intel Sodaville GPIO.
+
config GPIO_TIMBERDALE
bool "Support for timberdale GPIO IP"
depends on MFD_TIMBERDALE && GPIOLIB && HAS_IOMEM
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index becef59..7fbc00d 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_GPIO_PCH) += pch_gpio.o
obj-$(CONFIG_GPIO_PL061) += pl061.o
obj-$(CONFIG_GPIO_STMPE) += stmpe-gpio.o
obj-$(CONFIG_GPIO_TC3589X) += tc3589x-gpio.o
+obj-$(CONFIG_GPIO_SODAVILLE) += sodaville_gpio.o
obj-$(CONFIG_GPIO_TIMBERDALE) += timbgpio.o
obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o
obj-$(CONFIG_GPIO_UCB1400) += ucb1400_gpio.o
diff --git a/drivers/gpio/sodaville_gpio.c b/drivers/gpio/sodaville_gpio.c
new file mode 100644
index 0000000..1fcdbb0
--- /dev/null
+++ b/drivers/gpio/sodaville_gpio.c
@@ -0,0 +1,421 @@
+/*
+ * GPIO interface for Intel Sodaville SoCs.
+ *
+ * Copyright (c) 2010, 2011 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 2 as published
+ * by the Free Software Foundation.
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/of_irq.h>
+
+static DEFINE_SPINLOCK(gpio_lock);
+
+#define DRV_NAME "sdv_gpio"
+#define SDV_NUM_PUB_GPIOS 12
+#define PCI_DEVICE_ID_SDV_GPIO 0x2e67
+#define GPIO_BAR 0
+
+#define GPOUTR 0x00
+#define GPOER 0x04
+#define GPINR 0x08
+#define GPSTR 0x0c
+#define GPIT1R0 0x10
+#define GPIO_INT 0x14
+#define GPIT1R1 0x18
+#define GPMUXCTL 0x1c
+
+void __iomem *gpio_pub_base;
+
+struct sdv_irq_chip_data {
+ int irq_base;
+ struct irq_domain id;
+};
+
+static void sdv_gpio_pub_mask_irq(struct irq_data *irq)
+{
+ struct sdv_irq_chip_data *data = irq_data_get_irq_chip_data(irq);
+ u32 reg;
+
+ reg = readl(gpio_pub_base + GPIO_INT);
+ reg &= ~BIT(irq->irq - data->irq_base);
+ writel(reg, gpio_pub_base + GPIO_INT);
+}
+
+static void sdv_gpio_pub_ack_irq(struct irq_data *irq)
+{
+ struct sdv_irq_chip_data *data = irq_data_get_irq_chip_data(irq);
+ u32 reg;
+
+ reg = (BIT(irq->irq - data->irq_base));
+ writel(reg, gpio_pub_base + GPSTR);
+}
+
+static void sdv_gpio_pub_unmask_irq(struct irq_data *irq)
+{
+ struct sdv_irq_chip_data *data = irq_data_get_irq_chip_data(irq);
+ u32 reg;
+
+ reg = readl(gpio_pub_base + GPIO_INT);
+ reg |= (BIT(irq->irq - data->irq_base));
+ writel(reg, gpio_pub_base + GPIO_INT);
+}
+
+static int sdv_gpio_pub_set_type(struct irq_data *irq, unsigned int type)
+{
+ struct sdv_irq_chip_data *data = irq_data_get_irq_chip_data(irq);
+ u32 irq_offs = irq->irq - data->irq_base;
+ u32 reg;
+
+ if (irq_offs < 8)
+ reg = readl(gpio_pub_base + GPIT1R0);
+ else
+ reg = readl(gpio_pub_base + GPIT1R1);
+
+ switch (type) {
+ case IRQ_TYPE_LEVEL_HIGH:
+ reg &= ~BIT(4 * (irq_offs % 8));
+ break;
+
+ case IRQ_TYPE_LEVEL_LOW:
+ reg |= BIT(4 * (irq_offs % 8));
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (irq_offs < 8)
+ writel(reg, gpio_pub_base + GPIT1R0);
+ else
+ writel(reg, gpio_pub_base + GPIT1R1);
+
+ return 0;
+}
+
+static irqreturn_t sdv_gpio_pub_irq_handler(int irq, void *data)
+{
+ struct sdv_irq_chip_data *sdv_data = data;
+ u32 irq_stat = readl(gpio_pub_base + GPSTR);
+
+ irq_stat &= readl(gpio_pub_base + GPIO_INT);
+ if (!irq_stat)
+ return IRQ_NONE;
+
+ while (irq_stat) {
+ int irq_bit = __fls(irq_stat);
+
+ generic_handle_irq(sdv_data->irq_base + irq_bit);
+ irq_stat &= ~BIT(irq_bit);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static struct irq_chip sdv_gpio_pub_irq_chip = {
+ .name = "sdv-gpio",
+ .irq_mask = sdv_gpio_pub_mask_irq,
+ .irq_eoi = sdv_gpio_pub_ack_irq,
+ .irq_unmask = sdv_gpio_pub_unmask_irq,
+ .irq_set_type = sdv_gpio_pub_set_type,
+};
+
+static int sdv_xlate(struct irq_domain *h, const u32 *intspec, u32 intsize,
+ u32 *out_hwirq, u32 *out_type)
+{
+ struct sdv_irq_chip_data *sdv_data = h->priv;
+ u32 line, type;
+
+ if (intsize < 2)
+ return -EINVAL;
+
+ /* irqs are offset by sdv_data->irq_base */
+ line = *intspec;
+ *out_hwirq = line + sdv_data->irq_base;
+
+ intspec++;
+ type = *intspec;
+
+ /* Only level interrupts are supported by the IRQ chip */
+ switch (type) {
+ case 1:
+ *out_type = IRQ_TYPE_LEVEL_LOW;
+ break;
+ case 2:
+ *out_type = IRQ_TYPE_LEVEL_HIGH;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static __devinit int register_irqsupport(struct pci_dev *pdev)
+{
+ struct sdv_irq_chip_data *sdv_data;
+ int irq;
+ int last_irq;
+ int ret = -1;
+
+ sdv_data = kzalloc(sizeof(struct sdv_irq_chip_data), GFP_KERNEL);
+ if (!sdv_data) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = irq_alloc_descs(-1, 0, SDV_NUM_PUB_GPIOS, -1);
+ if (ret < 0)
+ goto out_kfree;
+
+ sdv_data->irq_base = ret;
+
+ /* mask + ACK all interrupt sources */
+ writel(0, gpio_pub_base + GPIO_INT);
+ writel((1 << 11) - 1, gpio_pub_base + GPSTR);
+
+ ret = request_irq(pdev->irq, sdv_gpio_pub_irq_handler, IRQF_SHARED,
+ "sdv_gpio", sdv_data);
+ if (ret)
+ goto out_free_desc;
+
+ /*
+ * This gpio irq controller latches level irqs. Testing shows that if
+ * we unmask & ACK the IRQ before the source of the interrupt is gone
+ * then the interrupt is active again.
+ */
+ last_irq = sdv_data->irq_base + SDV_NUM_PUB_GPIOS;
+ for (irq = sdv_data->irq_base; irq < last_irq; irq++) {
+ irq_set_chip_and_handler_name(irq, &sdv_gpio_pub_irq_chip,
+ handle_fasteoi_irq, "fasteoi");
+ irq_set_chip_data(irq, sdv_data);
+ }
+
+ pci_set_drvdata(pdev, sdv_data);
+
+ sdv_data->id.controller = pdev->dev.of_node;
+ sdv_data->id.xlate = sdv_xlate;
+ sdv_data->id.priv = sdv_data;
+ irq_add_of_interrupt_host(&sdv_data->id);
+
+ return 0;
+
+out_free_desc:
+ irq_free_descs(sdv_data->irq_base, SDV_NUM_PUB_GPIOS);
+out_kfree:
+ kfree(sdv_data);
+out:
+ pdev->dev.p = 0;
+ return ret;
+}
+
+static void unregister_irqsupport(struct pci_dev *pdev)
+{
+ struct sdv_irq_chip_data *sdv_data = pci_get_drvdata(pdev);
+
+ if (sdv_data) {
+ irq_remove_of_interrupt_host(&sdv_data->id);
+ free_irq(pdev->irq, sdv_data);
+ irq_free_descs(sdv_data->irq_base, SDV_NUM_PUB_GPIOS);
+ kfree(sdv_data);
+ }
+}
+
+static int sdv_gpio_is_output(unsigned gpio_num)
+{
+ return readl(gpio_pub_base + GPOER) & BIT(gpio_num);
+}
+
+static int sdv_gpio_pub_get(struct gpio_chip *gc, unsigned gpio_num)
+{
+ u32 reg;
+
+ if (sdv_gpio_is_output(gpio_num))
+ reg = readl(gpio_pub_base + GPOUTR);
+ else
+ reg = readl(gpio_pub_base + GPINR);
+
+ return (reg & BIT(gpio_num)) ? 1 : 0;
+}
+
+static void sdv_gpio_pub_set(struct gpio_chip *gc,
+ unsigned gpio_num, int val)
+{
+ u32 curr_vals;
+
+ spin_lock(&gpio_lock);
+
+ curr_vals = readl(gpio_pub_base + GPOUTR);
+
+ if (val)
+ curr_vals |= BIT(gpio_num);
+ else
+ curr_vals &= ~BIT(gpio_num);
+
+ writel(curr_vals, gpio_pub_base + GPOUTR);
+ spin_unlock(&gpio_lock);
+}
+
+static int sdv_gpio_pub_direction_in(struct gpio_chip *gc,
+ unsigned gpio_num)
+{
+ u32 curr_dirs;
+
+ spin_lock(&gpio_lock);
+
+ curr_dirs = readl(gpio_pub_base + GPOER);
+
+ if (curr_dirs & BIT(gpio_num))
+ writel(curr_dirs & ~BIT(gpio_num), gpio_pub_base + GPOER);
+
+ spin_unlock(&gpio_lock);
+ return 0;
+}
+
+static int sdv_gpio_pub_direction_out(struct gpio_chip *gc,
+ unsigned gpio_num, int val)
+{
+ u32 curr_dirs;
+
+ sdv_gpio_pub_set(gc, gpio_num, val);
+
+ spin_lock(&gpio_lock);
+
+ curr_dirs = readl(gpio_pub_base + GPOER);
+
+ if (!(curr_dirs & BIT(gpio_num)))
+ writel(curr_dirs | BIT(gpio_num), gpio_pub_base + GPOER);
+
+ spin_unlock(&gpio_lock);
+ return 0;
+}
+
+static struct gpio_chip sdv_gpio_pub = {
+ .label = "sdv_gpio",
+ .owner = THIS_MODULE,
+ .get = sdv_gpio_pub_get,
+ .set = sdv_gpio_pub_set,
+ .direction_input = sdv_gpio_pub_direction_in,
+ .direction_output = sdv_gpio_pub_direction_out,
+};
+
+static int __devinit sdv_gpio_probe(struct pci_dev *pdev,
+ const struct pci_device_id *pci_id)
+{
+ unsigned long addr;
+ const void *prop;
+ int len;
+ int ret;
+ u32 mux_val;
+
+ if (gpio_pub_base) {
+ dev_err(&pdev->dev, KERN_ERR "Driver does not (yet) support "
+ "multiple devices.\n");
+ return -EBUSY;
+ }
+ ret = pci_enable_device(pdev);
+ if (ret) {
+ dev_err(&pdev->dev, "can't enable device.\n");
+ goto done;
+ }
+
+ ret = pci_request_region(pdev, GPIO_BAR, DRV_NAME);
+ if (ret) {
+ dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", GPIO_BAR);
+ goto disable_pci;
+ }
+
+ addr = pci_resource_start(pdev, GPIO_BAR);
+ if (!addr)
+ goto release_reg;
+ gpio_pub_base = ioremap(addr, pci_resource_len(pdev, GPIO_BAR));
+
+ prop = of_get_property(pdev->dev.of_node, "muxctl", &len);
+ if (prop && len == 4) {
+ mux_val = of_read_number(prop, 1);
+ writel(mux_val, gpio_pub_base + GPMUXCTL);
+ }
+
+ sdv_gpio_pub.base = -1;
+ sdv_gpio_pub.ngpio = SDV_NUM_PUB_GPIOS;
+ sdv_gpio_pub.dev = &pdev->dev;
+
+ ret = gpiochip_add(&sdv_gpio_pub);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "gpiochip_add() failed.\n");
+ goto unmap;
+ }
+
+ ret = register_irqsupport(pdev);
+ if (ret)
+ goto unmap;
+
+ dev_info(&pdev->dev, "Sodaville GPIO driver registered.\n");
+
+ return 0;
+
+unmap:
+ iounmap(gpio_pub_base);
+ gpio_pub_base = NULL;
+release_reg:
+ pci_release_region(pdev, GPIO_BAR);
+disable_pci:
+ pci_disable_device(pdev);
+done:
+ return ret;
+}
+
+static void sdv_gpio_remove(struct pci_dev *pdev)
+{
+ if (!gpio_pub_base)
+ return;
+
+ unregister_irqsupport(pdev);
+
+ if (gpiochip_remove(&sdv_gpio_pub))
+ dev_err(&pdev->dev, "gpiochip_remove() failed.\n");
+
+ pci_release_region(pdev, GPIO_BAR);
+ gpio_pub_base = NULL;
+ pci_disable_device(pdev);
+}
+
+static struct pci_device_id sdv_gpio_pci_ids[] __devinitdata = {
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_SDV_GPIO) },
+ { 0, },
+};
+
+static struct pci_driver sdv_gpio_driver = {
+ .name = DRV_NAME,
+ .id_table = sdv_gpio_pci_ids,
+ .probe = sdv_gpio_probe,
+ .remove = sdv_gpio_remove,
+};
+
+static int __init sdv_gpio_init(void)
+{
+ return pci_register_driver(&sdv_gpio_driver);
+}
+module_init(sdv_gpio_init);
+
+static void __exit sdv_gpio_exit(void)
+{
+ pci_unregister_driver(&sdv_gpio_driver);
+}
+module_exit(sdv_gpio_exit);
+
+MODULE_AUTHOR("Hans J. Koch <hjk@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("GPIO interface for Intel Sodaville SoCs");
+MODULE_LICENSE("GPL v2");
--
1.7.4.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/