--- /dev/null
+/*
+ * GPIO controller driver for Intel Lynxpoint PCH chipset>
+ * Copyright (c) 2012, Intel Corporation.
+ *
+ * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/io.h>
+
+/* LynxPoint chipset has support for 94 gpio pins */
+
+#define LP_NUM_GPIO 94
+
+/* Bitmapped register offsets */
+#define LP_ACPI_OWNED 0x00 /* Bitmap, set by bios, 0: pin reserved for ACPI */
+#define LP_GC 0x7C /* set APIC IRQ to IRQ14 or IRQ15 for all pins */
+#define LP_INT_STAT 0x80
+#define LP_INT_ENABLE 0x90
+
+/* Each pin has two 32 bit config registers, starting at 0x100 */
+#define LP_CONFIG1 0x100
+#define LP_CONFIG2 0x104
+
+/* LP_CONFIG1 reg bits */
+#define OUT_LVL_BIT BIT(31)
+#define IN_LVL_BIT BIT(30)
+#define TRIG_SEL_BIT BIT(4) /* 0: Edge, 1: Level */
+#define INT_INV_BIT BIT(3) /* Invert interrupt triggering */
+#define DIR_BIT BIT(2) /* 0: Output, 1: Input */
+#define USE_SEL_BIT BIT(0) /* 0: Native, 1: GPIO */
+
+/* LP_CONFIG2 reg bits */
+#define GPINDIS_BIT BIT(2) /* disable input sensing */
+#define GPIWP_BIT (BIT(0) | BIT(1)) /* weak pull options */
+
+struct lp_gpio {
+ struct gpio_chip chip;
+ struct platform_device *pdev;
+ spinlock_t lock;
+ unsigned long reg_base;
+};
+
+/*
+ * Lynxpoint gpios are controlled through both bitmapped registers and
+ * per gpio specific registers. The bitmapped registers are in chunks of
+ * 3 x 32bit registers to cover all 94 gpios
+ *
+ * per gpio specific registers consist of two 32bit registers per gpio
+ * (LP_CONFIG1 and LP_CONFIG2), with 94 gpios there's a total of
+ * 188 config registes.
+ *
+ * A simplified view of the register layout look like this:
+ *
+ * LP_ACPI_OWNED[31:0] gpio ownerships for gpios 0-31 (bitmapped registers)
+ * LP_ACPI_OWNED[63:32] gpio ownerships for gpios 32-63
+ * LP_ACPI_OWNED[94:64] gpio ownerships for gpios 63-94
+ * ...
+ * LP_INT_ENABLE[31:0] ...
+ * LP_INT_ENABLE[63:31] ...
+ * LP_INT_ENABLE[94:64] ...
+ * LP0_CONFIG1 (gpio 0) config1 reg for gpio 0 (per gpio registers)
+ * LP0_CONFIG2 (gpio 0) config2 reg for gpio 0
+ * LP1_CONFIG1 (gpio 1) config1 reg for gpio 1
+ * LP1_CONFIG2 (gpio 1) config2 reg for gpio 1
+ * LP2_CONFIG1 (gpio 2) ...
+ * LP2_CONFIG2 (gpio 2) ...
+ * ...
+ * LP94_CONFIG1 (gpio 94) ...
+ * LP94_CONFIG2 (gpio 94) ...
+ */
+
+static unsigned long lp_gpio_reg(struct gpio_chip *chip, unsigned offset,
+ int reg)
+{
+ struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
+ int reg_offset;
+
+ if (reg == LP_CONFIG1 || reg == LP_CONFIG2)
+ /* per gpio specific config registers */
+ reg_offset = offset * 8;
+ else
+ /* bitmapped registers */
+ reg_offset = (offset / 32) * 4;
+
+ return lg->reg_base + reg + reg_offset;
+}
+
+static int lp_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
+ unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
+ unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2);
+ unsigned long acpi_use = lp_gpio_reg(chip, offset, LP_ACPI_OWNED);
+
+ pm_runtime_get(&lg->pdev->dev); /* should we put if failed */
+
+ /* Fail if BIOS reserved pin for ACPI use */
+ if (!(inl(acpi_use) & BIT(offset % 32))) {
+ dev_err(&lg->pdev->dev, "gpio %d reserved for ACPI\n", offset);
+ return -EBUSY;
+ }
+ /* Fail if pin is in alternate function mode (not GPIO mode) */
+ if (!(inl(reg) & USE_SEL_BIT))
+ return -ENODEV;
+
+ /* enable input sensing */
+ outl(inl(conf2) & ~GPINDIS_BIT, conf2);
+
+
+ return 0;
+}
+
+static void lp_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+ struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
+ unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2);
+
+ /* disable input sensing */
+ outl(inl(conf2) | GPINDIS_BIT, conf2);
+
+ pm_runtime_put(&lg->pdev->dev);
+}
+
+static int lp_irq_type(struct irq_data *d, unsigned type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip);
+ u32 hwirq = irqd_to_hwirq(d);
+ unsigned long flags;
+ u32 value;
+ unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_CONFIG1);
+
+ if (hwirq >= lg->chip.ngpio)
+ return -EINVAL;
+
+ spin_lock_irqsave(&lg->lock, flags);
+ value = inl(reg);
+
+ /* set both TRIG_SEL and INV bits to 0 for rising edge */
+ if (type & IRQ_TYPE_EDGE_RISING)
+ value &= ~(TRIG_SEL_BIT | INT_INV_BIT);
+
+ /* TRIG_SEL bit 0, INV bit 1 for falling edge */
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ value = (value | INT_INV_BIT) & ~TRIG_SEL_BIT;
+
+ /* TRIG_SEL bit 1, INV bit 0 for level low */
+ if (type & IRQ_TYPE_LEVEL_LOW)
+ value = (value | TRIG_SEL_BIT) & ~INT_INV_BIT;
+
+ /* TRIG_SEL bit 1, INV bit 1 for level high */
+ if (type & IRQ_TYPE_LEVEL_HIGH)
+ value |= TRIG_SEL_BIT | INT_INV_BIT;
+
+ outl(value, reg);
+ spin_unlock_irqrestore(&lg->lock, flags);
+
+ return 0;
+}
+
+static int lp_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
+ return !!(inl(reg) & IN_LVL_BIT);
+}
+
+static void lp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
+ unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
+ unsigned long flags;
+
+ spin_lock_irqsave(&lg->lock, flags);
+
+ if (value)
+ outl(inl(reg) | OUT_LVL_BIT, reg);
+ else
+ outl(inl(reg) & ~OUT_LVL_BIT, reg);
+
+ spin_unlock_irqrestore(&lg->lock, flags);
+}
+
+static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
+ unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
+ unsigned long flags;
+
+ spin_lock_irqsave(&lg->lock, flags);
+ outl(inl(reg) | DIR_BIT, reg);
+ spin_unlock_irqrestore(&lg->lock, flags);
+
+ return 0;
+}
+
+static int lp_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
+ unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
+ unsigned long flags;
+
+ lp_gpio_set(chip, offset, value);
+
+ spin_lock_irqsave(&lg->lock, flags);
+ outl(inl(reg) & ~DIR_BIT, reg);
+ spin_unlock_irqrestore(&lg->lock, flags);
+
+ return 0;
+}
+
+static void lp_gpio_irq_handler(unsigned hwirq, struct irq_desc *desc)
+{
+ struct irq_data *data = irq_desc_get_irq_data(desc);
+ struct gpio_chip *gc = irq_desc_get_handler_data(desc);
+ struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip);
+ struct irq_chip *chip = irq_data_get_irq_chip(data);
+ u32 base, pin, mask;
+ unsigned long reg, ena, pending;
+
+ /* check from GPIO controller which pin triggered the interrupt */
+ for (base = 0; base < lg->chip.ngpio; base += 32) {
+ reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);
+ ena = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE);
+
+ while ((pending = (inl(reg) & inl(ena)))) {
+ unsigned irq;
+
+ pin = __ffs(pending);
+ mask = BIT(pin);
+ /* Clear before handling so we don't lose an edge */
+ outl(mask, reg);
+ irq = irq_find_mapping(lg->chip.irqdomain, base + pin);
+ generic_handle_irq(irq);
+ }
+ }
+ chip->irq_eoi(data);
+}
+
+static void lp_irq_unmask(struct irq_data *d)
+{
+}
+
+static void lp_irq_mask(struct irq_data *d)
+{
+}
+
+static void lp_irq_enable(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip);
+ u32 hwirq = irqd_to_hwirq(d);
+ unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
+ unsigned long flags;
+
+ spin_lock_irqsave(&lg->lock, flags);
+ outl(inl(reg) | BIT(hwirq % 32), reg);
+ spin_unlock_irqrestore(&lg->lock, flags);
+}
+
+static void lp_irq_disable(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip);
+ u32 hwirq = irqd_to_hwirq(d);
+ unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
+ unsigned long flags;
+
+ spin_lock_irqsave(&lg->lock, flags);
+ outl(inl(reg) & ~BIT(hwirq % 32), reg);
+ spin_unlock_irqrestore(&lg->lock, flags);
+}
+
+static struct irq_chip lp_irqchip = {
+ .name = "LP-GPIO",
+ .irq_mask = lp_irq_mask,
+ .irq_unmask = lp_irq_unmask,
+ .irq_enable = lp_irq_enable,
+ .irq_disable = lp_irq_disable,
+ .irq_set_type = lp_irq_type,
+ .flags = IRQCHIP_SKIP_SET_WAKE,
+};
+
+static void lp_gpio_irq_init_hw(struct lp_gpio *lg)
+{
+ unsigned long reg;
+ unsigned base;
+
+ for (base = 0; base < lg->chip.ngpio; base += 32) {
+ /* disable gpio pin interrupts */
+ reg = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE);
+ outl(0, reg);
+ /* Clear interrupt status register */
+ reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);
+ outl(0xffffffff, reg);
+ }
+}
+
+static int lp_gpio_probe(struct platform_device *pdev)
+{
+ struct lp_gpio *lg;
+ struct gpio_chip *gc;
+ struct resource *io_rc, *irq_rc;
+ struct device *dev = &pdev->dev;
+ unsigned long reg_len;
+ int ret = -ENODEV;
+
+ lg = devm_kzalloc(dev, sizeof(struct lp_gpio), GFP_KERNEL);
+ if (!lg)
+ return -ENOMEM;
+
+ lg->pdev = pdev;
+ platform_set_drvdata(pdev, lg);
+
+ io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ irq_rc = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+
+ if (!io_rc) {
+ dev_err(dev, "missing IO resources\n");
+ return -EINVAL;
+ }
+
+ lg->reg_base = io_rc->start;
+ reg_len = resource_size(io_rc);
+
+ if (!devm_request_region(dev, lg->reg_base, reg_len, "lp-gpio")) {
+ dev_err(dev, "failed requesting IO region 0x%x\n",
+ (unsigned int)lg->reg_base);
+ return -EBUSY;
+ }
+
+ spin_lock_init(&lg->lock);
+
+ gc = &lg->chip;
+ gc->label = dev_name(dev);
+ gc->owner = THIS_MODULE;
+ gc->request = lp_gpio_request;
+ gc->free = lp_gpio_free;
+ gc->direction_input = lp_gpio_direction_input;
+ gc->direction_output = lp_gpio_direction_output;
+ gc->get = lp_gpio_get;
+ gc->set = lp_gpio_set;
+ gc->base = -1;
+ gc->ngpio = LP_NUM_GPIO;
+ gc->can_sleep = false;
+ gc->dev = dev;
+
+ ret = gpiochip_add(gc);
+ if (ret) {
+ dev_err(dev, "failed adding lp-gpio chip\n");
+ return ret;
+ }
+
+ /* set up interrupts */
+ if (irq_rc && irq_rc->start) {
+ lp_gpio_irq_init_hw(lg);
+ ret = gpiochip_irqchip_add(gc, &lp_irqchip, 0,
+ handle_simple_irq, IRQ_TYPE_NONE);
+ if (ret) {
+ dev_err(dev, "failed to add irqchip\n");
+ gpiochip_remove(gc);
+ return ret;
+ }
+
+ gpiochip_set_chained_irqchip(gc, &lp_irqchip,
+ (unsigned)irq_rc->start,
+ lp_gpio_irq_handler);
+ }
+
+ pm_runtime_enable(dev);
+
+ return 0;
+}
+
+static int lp_gpio_runtime_suspend(struct device *dev)
+{
+ return 0;
+}
+
+static int lp_gpio_runtime_resume(struct device *dev)
+{
+ return 0;
+}
+
+static int lp_gpio_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct lp_gpio *lg = platform_get_drvdata(pdev);
+ unsigned long reg;
+ int i;
+
+ /* on some hardware suspend clears input sensing, re-enable it here */
+ for (i = 0; i < lg->chip.ngpio; i++) {
+ if (gpiochip_is_requested(&lg->chip, i) != NULL) {
+ reg = lp_gpio_reg(&lg->chip, i, LP_CONFIG2);
+ outl(inl(reg) & ~GPINDIS_BIT, reg);
+ }
+ }
+ return 0;
+}
+
+static const struct dev_pm_ops lp_gpio_pm_ops = {
+ .runtime_suspend = lp_gpio_runtime_suspend,
+ .runtime_resume = lp_gpio_runtime_resume,
+ .resume = lp_gpio_resume,
+};
+
+static const struct acpi_device_id lynxpoint_gpio_acpi_match[] = {
+ { "INT33C7", 0 },
+ { "INT3437", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, lynxpoint_gpio_acpi_match);
+
+static int lp_gpio_remove(struct platform_device *pdev)
+{
+ struct lp_gpio *lg = platform_get_drvdata(pdev);
+ pm_runtime_disable(&pdev->dev);
+ gpiochip_remove(&lg->chip);
+ return 0;
+}
+
+static struct platform_driver lp_gpio_driver = {
+ .probe = lp_gpio_probe,
+ .remove = lp_gpio_remove,
+ .driver = {
+ .name = "lp_gpio",
+ .pm = &lp_gpio_pm_ops,
+ .acpi_match_table = ACPI_PTR(lynxpoint_gpio_acpi_match),
+ },
+};
+
+static int __init lp_gpio_init(void)
+{
+ return platform_driver_register(&lp_gpio_driver);
+}
+
+static void __exit lp_gpio_exit(void)
+{
+ platform_driver_unregister(&lp_gpio_driver);
+}
+
+subsys_initcall(lp_gpio_init);
+module_exit(lp_gpio_exit);
+
+MODULE_AUTHOR("Mathias Nyman (Intel)");
+MODULE_DESCRIPTION("GPIO interface for Intel Lynxpoint");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lp_gpio");
Code Review / kvmfornfv.git / blobdiff