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Subject[PATCH v2 2/2] gpio: Add a driver for Sodaville GPIO controller
Date
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@linutronix.de>
[torbenh@linutronix.de: make it work after the irq namespace cleanup,
add some device tree entries.]
Signed-off-by: Torben Hohn <torbenh@linutronix.de>
[bigeasy@linutronix.de: convert to generic irq & gpio chip]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
.../devicetree/bindings/gpio/sodaville.txt | 48 +++
arch/x86/platform/ce4100/falconfalls.dts | 7 +-
drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-sodaville.c | 302 ++++++++++++++++++++
5 files changed, 364 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/sodaville.txt
create mode 100644 drivers/gpio/gpio-sodaville.c
diff --git a/Documentation/devicetree/bindings/gpio/sodaville.txt b/Documentation/devicetree/bindings/gpio/sodaville.txt
new file mode 100644
index 0000000..563eff2
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/sodaville.txt
@@ -0,0 +1,48 @@
+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 intel,muxctl property which holds the
+value which is written into the MUXCNTL register.
+
+There is no compatible property for now because the driver is probed via
+PCI id (vendor 0x8086 device 0x2e67).
+
+The interrupt specifier consists of two cells encoded as follows:
+ - <1st cell>: The interrupt-number that identifies the interrupt source.
+ - <2nd cell>: The level-sense information, encoded as follows:
+ 4 - active high level-sensitive
+ 8 - active low level-sensitive
+
+Example of the GPIO device and one user:
+
+ pcigpio: gpio@b,1 {
+ /* two cells for GPIO and interrupt */
+ #gpio-cells = <2>;
+ #interrupt-cells = <2>;
+ compatible = "pci8086,2e67.2",
+ "pci8086,2e67",
+ "pciclassff0000",
+ "pciclassff00";
+
+ reg = <0x15900 0x0 0x0 0x0 0x0>;
+ /* Interrupt line of the gpio device */
+ interrupts = <15 1>;
+ /* It is an interrupt and GPIO controller itself */
+ interrupt-controller;
+ gpio-controller;
+ intel,muxctl = <0>;
+ };
+
+ testuser@20 {
+ compatible = "example,testuser";
+ /* User the 11th GPIO line as an active high triggered
+ * level interrupt
+ */
+ interrupts = <11 8>;
+ interrupt-parent = <&pcigpio>;
+ /* Use this GPIO also with the gpio functions */
+ gpios = <&pcigpio 11 0>;
+ };
diff --git a/arch/x86/platform/ce4100/falconfalls.dts b/arch/x86/platform/ce4100/falconfalls.dts
index e70be38..ce874f8 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;
+ intel,muxctl = <0>;
};

i2c-controller@b,2 {
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 9f06e63..4765f63 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -376,6 +376,14 @@ 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 && OF
+ select GPIO_GENERIC
+ select GENERIC_IRQ_CHIP
+ help
+ Say Y here to support Intel Sodaville GPIO.
+
config GPIO_TIMBERDALE
bool "Support for timberdale GPIO IP"
depends on MFD_TIMBERDALE && HAS_IOMEM
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 0fbdd75..cc6d662 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_GPIO_S5PV210) += gpio-s5pv210.o

obj-$(CONFIG_GPIO_SCH) += gpio-sch.o
obj-$(CONFIG_GPIO_STMPE) += gpio-stmpe.o
+obj-$(CONFIG_GPIO_SODAVILLE) += gpio-sodaville.o
obj-$(CONFIG_GPIO_SX150X) += gpio-sx150x.o
obj-$(CONFIG_GPIO_TC3589X) += gpio-tc3589x.o
obj-$(CONFIG_ARCH_TEGRA) += gpio-tegra.o
diff --git a/drivers/gpio/gpio-sodaville.c b/drivers/gpio/gpio-sodaville.c
new file mode 100644
index 0000000..9ba15d3
--- /dev/null
+++ b/drivers/gpio/gpio-sodaville.c
@@ -0,0 +1,302 @@
+/*
+ * 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>
+#include <linux/basic_mmio_gpio.h>
+
+#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
+
+struct sdv_gpio_chip_data {
+ int irq_base;
+ void __iomem *gpio_pub_base;
+ struct irq_domain id;
+ struct irq_chip_generic *gc;
+ struct bgpio_chip bgpio;
+};
+
+static int sdv_gpio_pub_set_type(struct irq_data *d, unsigned int type)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct sdv_gpio_chip_data *sd = gc->private;
+ void __iomem *type_reg;
+ u32 irq_offs = d->irq - sd->irq_base;
+ u32 reg;
+
+ if (irq_offs < 8)
+ type_reg = sd->gpio_pub_base + GPIT1R0;
+ else
+ type_reg = sd->gpio_pub_base + GPIT1R1;
+
+ reg = readl(type_reg);
+
+ 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;
+ }
+
+ writel(reg, type_reg);
+ return 0;
+}
+
+static irqreturn_t sdv_gpio_pub_irq_handler(int irq, void *data)
+{
+ struct sdv_gpio_chip_data *sd = data;
+ u32 irq_stat = readl(sd->gpio_pub_base + GPSTR);
+
+ irq_stat &= readl(sd->gpio_pub_base + GPIO_INT);
+ if (!irq_stat)
+ return IRQ_NONE;
+
+ while (irq_stat) {
+ u32 irq_bit = __fls(irq_stat);
+
+ irq_stat &= ~BIT(irq_bit);
+ generic_handle_irq(sd->irq_base + irq_bit);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int sdv_xlate(struct irq_domain *h, struct device_node *node,
+ const u32 *intspec, u32 intsize, irq_hw_number_t *out_hwirq,
+ u32 *out_type)
+{
+ u32 line, type;
+
+ if (node != h->of_node)
+ return -EINVAL;
+
+ if (intsize < 2)
+ return -EINVAL;
+
+ line = *intspec;
+ *out_hwirq = line;
+
+ intspec++;
+ type = *intspec;
+
+ switch (type) {
+ case IRQ_TYPE_LEVEL_LOW:
+ case IRQ_TYPE_LEVEL_HIGH:
+ *out_type = type;
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static struct irq_domain_ops irq_domain_sdv_ops = {
+ .dt_translate = sdv_xlate,
+};
+
+static __devinit int sdv_register_irqsupport(struct sdv_gpio_chip_data *sd,
+ struct pci_dev *pdev)
+{
+ struct irq_chip_type *ct;
+ int ret;
+
+ sd->irq_base = irq_alloc_descs(-1, 0, SDV_NUM_PUB_GPIOS, -1);
+ if (sd->irq_base < 0)
+ return sd->irq_base;
+
+ /* mask + ACK all interrupt sources */
+ writel(0, sd->gpio_pub_base + GPIO_INT);
+ writel((1 << 11) - 1, sd->gpio_pub_base + GPSTR);
+
+ ret = request_irq(pdev->irq, sdv_gpio_pub_irq_handler, IRQF_SHARED,
+ "sdv_gpio", sd);
+ if (ret)
+ goto out_free_desc;
+
+ sd->id.irq_base = sd->irq_base;
+ sd->id.of_node = of_node_get(pdev->dev.of_node);
+ sd->id.ops = &irq_domain_sdv_ops;
+
+ /*
+ * 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.
+ */
+ sd->gc = irq_alloc_generic_chip("sdv-gpio", 1, sd->irq_base,
+ sd->gpio_pub_base, handle_fasteoi_irq);
+ if (!sd->gc) {
+ ret = -ENOMEM;
+ goto out_free_irq;
+ }
+
+ sd->gc->private = sd;
+ ct = sd->gc->chip_types;
+ ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
+ ct->regs.eoi = GPSTR;
+ ct->regs.mask = GPIO_INT;
+ ct->chip.irq_mask = irq_gc_mask_clr_bit;
+ ct->chip.irq_unmask = irq_gc_mask_set_bit;
+ ct->chip.irq_eoi = irq_gc_eoi;
+ ct->chip.irq_set_type = sdv_gpio_pub_set_type;
+
+ irq_setup_generic_chip(sd->gc, IRQ_MSK(SDV_NUM_PUB_GPIOS),
+ IRQ_GC_INIT_MASK_CACHE, IRQ_NOREQUEST,
+ IRQ_LEVEL | IRQ_NOPROBE);
+
+ irq_domain_add(&sd->id);
+ return 0;
+out_free_irq:
+ free_irq(pdev->irq, sd);
+out_free_desc:
+ irq_free_descs(sd->irq_base, SDV_NUM_PUB_GPIOS);
+ return ret;
+}
+
+static int __devinit sdv_gpio_probe(struct pci_dev *pdev,
+ const struct pci_device_id *pci_id)
+{
+ struct sdv_gpio_chip_data *sd;
+ unsigned long addr;
+ const void *prop;
+ int len;
+ int ret;
+ u32 mux_val;
+
+ sd = kzalloc(sizeof(struct sdv_gpio_chip_data), GFP_KERNEL);
+ if (!sd)
+ return -ENOMEM;
+ 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;
+ sd->gpio_pub_base = ioremap(addr, pci_resource_len(pdev, GPIO_BAR));
+
+ prop = of_get_property(pdev->dev.of_node, "intel,muxctl", &len);
+ if (prop && len == 4) {
+ mux_val = of_read_number(prop, 1);
+ writel(mux_val, sd->gpio_pub_base + GPMUXCTL);
+ }
+
+ ret = bgpio_init(&sd->bgpio, &pdev->dev, 4,
+ sd->gpio_pub_base + GPINR, sd->gpio_pub_base + GPOUTR,
+ NULL, sd->gpio_pub_base + GPOER, NULL, false);
+ if (ret)
+ goto unmap;
+ sd->bgpio.gc.ngpio = SDV_NUM_PUB_GPIOS;
+
+ ret = gpiochip_add(&sd->bgpio.gc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "gpiochip_add() failed.\n");
+ goto unmap;
+ }
+
+ ret = sdv_register_irqsupport(sd, pdev);
+ if (ret)
+ goto unmap;
+
+ pci_set_drvdata(pdev, sd);
+ dev_info(&pdev->dev, "Sodaville GPIO driver registered.\n");
+ return 0;
+
+unmap:
+ iounmap(sd->gpio_pub_base);
+release_reg:
+ pci_release_region(pdev, GPIO_BAR);
+disable_pci:
+ pci_disable_device(pdev);
+done:
+ kfree(sd);
+ return ret;
+}
+
+static void sdv_gpio_remove(struct pci_dev *pdev)
+{
+ struct sdv_gpio_chip_data *sd = pci_get_drvdata(pdev);
+
+ irq_domain_del(&sd->id);
+ free_irq(pdev->irq, sd);
+ irq_free_descs(sd->irq_base, SDV_NUM_PUB_GPIOS);
+
+ if (gpiochip_remove(&sd->bgpio.gc))
+ dev_err(&pdev->dev, "gpiochip_remove() failed.\n");
+
+ pci_release_region(pdev, GPIO_BAR);
+ iounmap(sd->gpio_pub_base);
+ pci_disable_device(pdev);
+ kfree(sd);
+}
+
+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@linutronix.de>");
+MODULE_DESCRIPTION("GPIO interface for Intel Sodaville SoCs");
+MODULE_LICENSE("GPL v2");
--
1.7.4.4


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