--- /dev/null
+/*
+ * AMD Promontory GPIO driver
+ *
+ * Copyright (C) 2015 ASMedia Technology Inc.
+ * Author: YD Tseng <yd_tseng@asmedia.com.tw>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio/driver.h>
+#include <linux/spinlock.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+
+#define PT_TOTAL_GPIO 8
+
+/* PCI-E MMIO register offsets */
+#define PT_DIRECTION_REG 0x00
+#define PT_INPUTDATA_REG 0x04
+#define PT_OUTPUTDATA_REG 0x08
+#define PT_CLOCKRATE_REG 0x0C
+#define PT_SYNC_REG 0x28
+
+struct pt_gpio_chip {
+ struct gpio_chip gc;
+ void __iomem *reg_base;
+ spinlock_t lock;
+};
+
+#define to_pt_gpio(c) container_of(c, struct pt_gpio_chip, gc)
+
+static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+ struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+ unsigned long flags;
+ u32 using_pins;
+
+ dev_dbg(gc->dev, "pt_gpio_request offset=%x\n", offset);
+
+ spin_lock_irqsave(&pt_gpio->lock, flags);
+
+ using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
+ if (using_pins & BIT(offset)) {
+ dev_warn(gc->dev, "PT GPIO pin %x reconfigured\n",
+ offset);
+ spin_unlock_irqrestore(&pt_gpio->lock, flags);
+ return -EINVAL;
+ }
+
+ writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);
+
+ spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+ return 0;
+}
+
+static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)
+{
+ struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+ unsigned long flags;
+ u32 using_pins;
+
+ spin_lock_irqsave(&pt_gpio->lock, flags);
+
+ using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
+ using_pins &= ~BIT(offset);
+ writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);
+
+ spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+ dev_dbg(gc->dev, "pt_gpio_free offset=%x\n", offset);
+}
+
+static void pt_gpio_set_value(struct gpio_chip *gc, unsigned offset, int value)
+{
+ struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+ unsigned long flags;
+ u32 data;
+
+ dev_dbg(gc->dev, "pt_gpio_set_value offset=%x, value=%x\n",
+ offset, value);
+
+ spin_lock_irqsave(&pt_gpio->lock, flags);
+
+ data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+ data &= ~BIT(offset);
+ if (value)
+ data |= BIT(offset);
+ writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+
+ spin_unlock_irqrestore(&pt_gpio->lock, flags);
+}
+
+static int pt_gpio_get_value(struct gpio_chip *gc, unsigned offset)
+{
+ struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+ unsigned long flags;
+ u32 data;
+
+ spin_lock_irqsave(&pt_gpio->lock, flags);
+
+ data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
+
+ /* configure as output */
+ if (data & BIT(offset))
+ data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+ else /* configure as input */
+ data = readl(pt_gpio->reg_base + PT_INPUTDATA_REG);
+
+ spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+ data >>= offset;
+ data &= 1;
+
+ dev_dbg(gc->dev, "pt_gpio_get_value offset=%x, value=%x\n",
+ offset, data);
+
+ return data;
+}
+
+static int pt_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+ struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+ unsigned long flags;
+ u32 data;
+
+ dev_dbg(gc->dev, "pt_gpio_dirction_input offset=%x\n", offset);
+
+ spin_lock_irqsave(&pt_gpio->lock, flags);
+
+ data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
+ data &= ~BIT(offset);
+ writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);
+
+ spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+ return 0;
+}
+
+static int pt_gpio_direction_output(struct gpio_chip *gc,
+ unsigned offset, int value)
+{
+ struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);
+ unsigned long flags;
+ u32 data;
+
+ dev_dbg(gc->dev, "pt_gpio_direction_output offset=%x, value=%x\n",
+ offset, value);
+
+ spin_lock_irqsave(&pt_gpio->lock, flags);
+
+ data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+ if (value)
+ data |= BIT(offset);
+ else
+ data &= ~BIT(offset);
+ writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG);
+
+ data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);
+ data |= BIT(offset);
+ writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);
+
+ spin_unlock_irqrestore(&pt_gpio->lock, flags);
+
+ return 0;
+}
+
+static int pt_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct acpi_device *acpi_dev;
+ acpi_handle handle = ACPI_HANDLE(dev);
+ struct pt_gpio_chip *pt_gpio;
+ struct resource *res_mem;
+ int ret = 0;
+
+ if (acpi_bus_get_device(handle, &acpi_dev)) {
+ dev_err(dev, "PT GPIO device node not found\n");
+ return -ENODEV;
+ }
+
+ pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL);
+ if (!pt_gpio)
+ return -ENOMEM;
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res_mem) {
+ dev_err(&pdev->dev, "Failed to get MMIO resource for PT GPIO.\n");
+ return -EINVAL;
+ }
+ pt_gpio->reg_base = devm_ioremap_resource(dev, res_mem);
+ if (IS_ERR(pt_gpio->reg_base)) {
+ dev_err(&pdev->dev, "Failed to map MMIO resource for PT GPIO.\n");
+ return PTR_ERR(pt_gpio->reg_base);
+ }
+
+ spin_lock_init(&pt_gpio->lock);
+
+ pt_gpio->gc.label = pdev->name;
+ pt_gpio->gc.owner = THIS_MODULE;
+ pt_gpio->gc.dev = dev;
+ pt_gpio->gc.request = pt_gpio_request;
+ pt_gpio->gc.free = pt_gpio_free;
+ pt_gpio->gc.direction_input = pt_gpio_direction_input;
+ pt_gpio->gc.direction_output = pt_gpio_direction_output;
+ pt_gpio->gc.get = pt_gpio_get_value;
+ pt_gpio->gc.set = pt_gpio_set_value;
+ pt_gpio->gc.base = -1;
+ pt_gpio->gc.ngpio = PT_TOTAL_GPIO;
+#if defined(CONFIG_OF_GPIO)
+ pt_gpio->gc.of_node = pdev->dev.of_node;
+#endif
+ ret = gpiochip_add(&pt_gpio->gc);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to register GPIO lib\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, pt_gpio);
+
+ /* initialize register setting */
+ writel(0, pt_gpio->reg_base + PT_SYNC_REG);
+ writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);
+
+ dev_dbg(&pdev->dev, "PT GPIO driver loaded\n");
+ return ret;
+}
+
+static int pt_gpio_remove(struct platform_device *pdev)
+{
+ struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev);
+
+ gpiochip_remove(&pt_gpio->gc);
+
+ return 0;
+}
+
+static const struct acpi_device_id pt_gpio_acpi_match[] = {
+ { "AMDF030", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match);
+
+static struct platform_driver pt_gpio_driver = {
+ .driver = {
+ .name = "pt-gpio",
+ .acpi_match_table = ACPI_PTR(pt_gpio_acpi_match),
+ },
+ .probe = pt_gpio_probe,
+ .remove = pt_gpio_remove,
+};
+
+module_platform_driver(pt_gpio_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>");
+MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
Code Review / kvmfornfv.git / blobdiff