summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-amdpt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/gpio/gpio-amdpt.c')
-rw-r--r--drivers/gpio/gpio-amdpt.c155
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-amdpt.c b/drivers/gpio/gpio-amdpt.c
new file mode 100644
index 000000000..07c6d0900
--- /dev/null
+++ b/drivers/gpio/gpio-amdpt.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Promontory GPIO driver
+ *
+ * Copyright (C) 2015 ASMedia Technology Inc.
+ * Author: YD Tseng <yd_tseng@asmedia.com.tw>
+ */
+
+#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
+#define PT_TOTAL_GPIO_EX 24
+
+/* 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;
+};
+
+static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+ struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
+ unsigned long flags;
+ u32 using_pins;
+
+ dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset);
+
+ raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
+
+ using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
+ if (using_pins & BIT(offset)) {
+ dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n",
+ offset);
+ raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+ return -EINVAL;
+ }
+
+ writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);
+
+ raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+
+ return 0;
+}
+
+static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)
+{
+ struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
+ unsigned long flags;
+ u32 using_pins;
+
+ raw_spin_lock_irqsave(&gc->bgpio_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);
+
+ raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+
+ dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset);
+}
+
+static int pt_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct pt_gpio_chip *pt_gpio;
+ int ret = 0;
+
+ if (!ACPI_COMPANION(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;
+
+ pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pt_gpio->reg_base)) {
+ dev_err(dev, "Failed to map MMIO resource for PT GPIO.\n");
+ return PTR_ERR(pt_gpio->reg_base);
+ }
+
+ ret = bgpio_init(&pt_gpio->gc, dev, 4,
+ pt_gpio->reg_base + PT_INPUTDATA_REG,
+ pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL,
+ pt_gpio->reg_base + PT_DIRECTION_REG, NULL,
+ BGPIOF_READ_OUTPUT_REG_SET);
+ if (ret) {
+ dev_err(dev, "bgpio_init failed\n");
+ return ret;
+ }
+
+ pt_gpio->gc.owner = THIS_MODULE;
+ pt_gpio->gc.request = pt_gpio_request;
+ pt_gpio->gc.free = pt_gpio_free;
+ pt_gpio->gc.ngpio = (uintptr_t)device_get_match_data(dev);
+
+ ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio);
+ if (ret) {
+ dev_err(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(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", PT_TOTAL_GPIO },
+ { "AMDIF030", PT_TOTAL_GPIO },
+ { "AMDIF031", PT_TOTAL_GPIO_EX },
+ { },
+};
+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");