1 files changed, 416 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-sch.c b/drivers/gpio/gpio-sch.c
new file mode 100644
index 000000000..8a83f7bf4
--- /dev/null
+++ b/drivers/gpio/gpio-sch.c
@@ -0,0 +1,416 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPIO interface for Intel Poulsbo SCH
+ *
+ *  Copyright (c) 2010 CompuLab Ltd
+ *  Author: Denis Turischev <denis@compulab.co.il>
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci_ids.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#define GEN	0x00
+#define GIO	0x04
+#define GLV	0x08
+#define GTPE	0x0c
+#define GTNE	0x10
+#define GGPE	0x14
+#define GSMI	0x18
+#define GTS	0x1c
+
+#define CORE_BANK_OFFSET	0x00
+#define RESUME_BANK_OFFSET	0x20
+
+/*
+ * iLB datasheet describes GPE0BLK registers, in particular GPE0E.GPIO bit.
+ * Document Number: 328195-001
+ */
+#define GPE0E_GPIO	14
+
+struct sch_gpio {
+	struct gpio_chip chip;
+	spinlock_t lock;
+	unsigned short iobase;
+	unsigned short resume_base;
+
+	/* GPE handling */
+	u32 gpe;
+	acpi_gpe_handler gpe_handler;
+};
+
+static unsigned int sch_gpio_offset(struct sch_gpio *sch, unsigned int gpio,
+				unsigned int reg)
+{
+	unsigned int base = CORE_BANK_OFFSET;
+
+	if (gpio >= sch->resume_base) {
+		gpio -= sch->resume_base;
+		base = RESUME_BANK_OFFSET;
+	}
+
+	return base + reg + gpio / 8;
+}
+
+static unsigned int sch_gpio_bit(struct sch_gpio *sch, unsigned int gpio)
+{
+	if (gpio >= sch->resume_base)
+		gpio -= sch->resume_base;
+	return gpio % 8;
+}
+
+static int sch_gpio_reg_get(struct sch_gpio *sch, unsigned int gpio, unsigned int reg)
+{
+	unsigned short offset, bit;
+	u8 reg_val;
+
+	offset = sch_gpio_offset(sch, gpio, reg);
+	bit = sch_gpio_bit(sch, gpio);
+
+	reg_val = !!(inb(sch->iobase + offset) & BIT(bit));
+
+	return reg_val;
+}
+
+static void sch_gpio_reg_set(struct sch_gpio *sch, unsigned int gpio, unsigned int reg,
+			     int val)
+{
+	unsigned short offset, bit;
+	u8 reg_val;
+
+	offset = sch_gpio_offset(sch, gpio, reg);
+	bit = sch_gpio_bit(sch, gpio);
+
+	reg_val = inb(sch->iobase + offset);
+
+	if (val)
+		outb(reg_val | BIT(bit), sch->iobase + offset);
+	else
+		outb((reg_val & ~BIT(bit)), sch->iobase + offset);
+}
+
+static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned int gpio_num)
+{
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sch->lock, flags);
+	sch_gpio_reg_set(sch, gpio_num, GIO, 1);
+	spin_unlock_irqrestore(&sch->lock, flags);
+	return 0;
+}
+
+static int sch_gpio_get(struct gpio_chip *gc, unsigned int gpio_num)
+{
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+
+	return sch_gpio_reg_get(sch, gpio_num, GLV);
+}
+
+static void sch_gpio_set(struct gpio_chip *gc, unsigned int gpio_num, int val)
+{
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sch->lock, flags);
+	sch_gpio_reg_set(sch, gpio_num, GLV, val);
+	spin_unlock_irqrestore(&sch->lock, flags);
+}
+
+static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned int gpio_num,
+				  int val)
+{
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sch->lock, flags);
+	sch_gpio_reg_set(sch, gpio_num, GIO, 0);
+	spin_unlock_irqrestore(&sch->lock, flags);
+
+	/*
+	 * according to the datasheet, writing to the level register has no
+	 * effect when GPIO is programmed as input.
+	 * Actually the level register is read-only when configured as input.
+	 * Thus presetting the output level before switching to output is _NOT_ possible.
+	 * Hence we set the level after configuring the GPIO as output.
+	 * But we cannot prevent a short low pulse if direction is set to high
+	 * and an external pull-up is connected.
+	 */
+	sch_gpio_set(gc, gpio_num, val);
+	return 0;
+}
+
+static int sch_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio_num)
+{
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+
+	if (sch_gpio_reg_get(sch, gpio_num, GIO))
+		return GPIO_LINE_DIRECTION_IN;
+
+	return GPIO_LINE_DIRECTION_OUT;
+}
+
+static const struct gpio_chip sch_gpio_chip = {
+	.label			= "sch_gpio",
+	.owner			= THIS_MODULE,
+	.direction_input	= sch_gpio_direction_in,
+	.get			= sch_gpio_get,
+	.direction_output	= sch_gpio_direction_out,
+	.set			= sch_gpio_set,
+	.get_direction		= sch_gpio_get_direction,
+};
+
+static int sch_irq_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+	irq_hw_number_t gpio_num = irqd_to_hwirq(d);
+	unsigned long flags;
+	int rising, falling;
+
+	switch (type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_EDGE_RISING:
+		rising = 1;
+		falling = 0;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		rising = 0;
+		falling = 1;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		rising = 1;
+		falling = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&sch->lock, flags);
+
+	sch_gpio_reg_set(sch, gpio_num, GTPE, rising);
+	sch_gpio_reg_set(sch, gpio_num, GTNE, falling);
+
+	irq_set_handler_locked(d, handle_edge_irq);
+
+	spin_unlock_irqrestore(&sch->lock, flags);
+
+	return 0;
+}
+
+static void sch_irq_ack(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+	irq_hw_number_t gpio_num = irqd_to_hwirq(d);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sch->lock, flags);
+	sch_gpio_reg_set(sch, gpio_num, GTS, 1);
+	spin_unlock_irqrestore(&sch->lock, flags);
+}
+
+static void sch_irq_mask_unmask(struct gpio_chip *gc, irq_hw_number_t gpio_num, int val)
+{
+	struct sch_gpio *sch = gpiochip_get_data(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sch->lock, flags);
+	sch_gpio_reg_set(sch, gpio_num, GGPE, val);
+	spin_unlock_irqrestore(&sch->lock, flags);
+}
+
+static void sch_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t gpio_num = irqd_to_hwirq(d);
+
+	sch_irq_mask_unmask(gc, gpio_num, 0);
+	gpiochip_disable_irq(gc, gpio_num);
+}
+
+static void sch_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t gpio_num = irqd_to_hwirq(d);
+
+	gpiochip_enable_irq(gc, gpio_num);
+	sch_irq_mask_unmask(gc, gpio_num, 1);
+}
+
+static const struct irq_chip sch_irqchip = {
+	.name = "sch_gpio",
+	.irq_ack = sch_irq_ack,
+	.irq_mask = sch_irq_mask,
+	.irq_unmask = sch_irq_unmask,
+	.irq_set_type = sch_irq_type,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static u32 sch_gpio_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
+{
+	struct sch_gpio *sch = context;
+	struct gpio_chip *gc = &sch->chip;
+	unsigned long core_status, resume_status;
+	unsigned long pending;
+	unsigned long flags;
+	int offset;
+	u32 ret;
+
+	spin_lock_irqsave(&sch->lock, flags);
+
+	core_status = inl(sch->iobase + CORE_BANK_OFFSET + GTS);
+	resume_status = inl(sch->iobase + RESUME_BANK_OFFSET + GTS);
+
+	spin_unlock_irqrestore(&sch->lock, flags);
+
+	pending = (resume_status << sch->resume_base) | core_status;
+	for_each_set_bit(offset, &pending, sch->chip.ngpio)
+		generic_handle_domain_irq(gc->irq.domain, offset);
+
+	/* Set returning value depending on whether we handled an interrupt */
+	ret = pending ? ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
+
+	/* Acknowledge GPE to ACPICA */
+	ret |= ACPI_REENABLE_GPE;
+
+	return ret;
+}
+
+static void sch_gpio_remove_gpe_handler(void *data)
+{
+	struct sch_gpio *sch = data;
+
+	acpi_disable_gpe(NULL, sch->gpe);
+	acpi_remove_gpe_handler(NULL, sch->gpe, sch->gpe_handler);
+}
+
+static int sch_gpio_install_gpe_handler(struct sch_gpio *sch)
+{
+	struct device *dev = sch->chip.parent;
+	acpi_status status;
+
+	status = acpi_install_gpe_handler(NULL, sch->gpe, ACPI_GPE_LEVEL_TRIGGERED,
+					  sch->gpe_handler, sch);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "Failed to install GPE handler for %u: %s\n",
+			sch->gpe, acpi_format_exception(status));
+		return -ENODEV;
+	}
+
+	status = acpi_enable_gpe(NULL, sch->gpe);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "Failed to enable GPE handler for %u: %s\n",
+			sch->gpe, acpi_format_exception(status));
+		acpi_remove_gpe_handler(NULL, sch->gpe, sch->gpe_handler);
+		return -ENODEV;
+	}
+
+	return devm_add_action_or_reset(dev, sch_gpio_remove_gpe_handler, sch);
+}
+
+static int sch_gpio_probe(struct platform_device *pdev)
+{
+	struct gpio_irq_chip *girq;
+	struct sch_gpio *sch;
+	struct resource *res;
+	int ret;
+
+	sch = devm_kzalloc(&pdev->dev, sizeof(*sch), GFP_KERNEL);
+	if (!sch)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!res)
+		return -EBUSY;
+
+	if (!devm_request_region(&pdev->dev, res->start, resource_size(res),
+				 pdev->name))
+		return -EBUSY;
+
+	spin_lock_init(&sch->lock);
+	sch->iobase = res->start;
+	sch->chip = sch_gpio_chip;
+	sch->chip.label = dev_name(&pdev->dev);
+	sch->chip.parent = &pdev->dev;
+
+	switch (pdev->id) {
+	case PCI_DEVICE_ID_INTEL_SCH_LPC:
+		sch->resume_base = 10;
+		sch->chip.ngpio = 14;
+
+		/*
+		 * GPIO[6:0] enabled by default
+		 * GPIO7 is configured by the CMC as SLPIOVR
+		 * Enable GPIO[9:8] core powered gpios explicitly
+		 */
+		sch_gpio_reg_set(sch, 8, GEN, 1);
+		sch_gpio_reg_set(sch, 9, GEN, 1);
+		/*
+		 * SUS_GPIO[2:0] enabled by default
+		 * Enable SUS_GPIO3 resume powered gpio explicitly
+		 */
+		sch_gpio_reg_set(sch, 13, GEN, 1);
+		break;
+
+	case PCI_DEVICE_ID_INTEL_ITC_LPC:
+		sch->resume_base = 5;
+		sch->chip.ngpio = 14;
+		break;
+
+	case PCI_DEVICE_ID_INTEL_CENTERTON_ILB:
+		sch->resume_base = 21;
+		sch->chip.ngpio = 30;
+		break;
+
+	case PCI_DEVICE_ID_INTEL_QUARK_X1000_ILB:
+		sch->resume_base = 2;
+		sch->chip.ngpio = 8;
+		break;
+
+	default:
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, sch);
+
+	girq = &sch->chip.irq;
+	gpio_irq_chip_set_chip(girq, &sch_irqchip);
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->parent_handler = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_bad_irq;
+
+	/* GPE setup is optional */
+	sch->gpe = GPE0E_GPIO;
+	sch->gpe_handler = sch_gpio_gpe_handler;
+
+	ret = sch_gpio_install_gpe_handler(sch);
+	if (ret)
+		dev_warn(&pdev->dev, "Can't setup GPE, no IRQ support\n");
+
+	return devm_gpiochip_add_data(&pdev->dev, &sch->chip, sch);
+}
+
+static struct platform_driver sch_gpio_driver = {
+	.driver = {
+		.name = "sch_gpio",
+	},
+	.probe		= sch_gpio_probe,
+};
+
+module_platform_driver(sch_gpio_driver);
+
+MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
+MODULE_DESCRIPTION("GPIO interface for Intel Poulsbo SCH");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:sch_gpio");