diff options
Diffstat (limited to 'drivers/gpio/gpio-amdpt.c')
| -rw-r--r-- | drivers/gpio/gpio-amdpt.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-amdpt.c b/drivers/gpio/gpio-amdpt.c new file mode 100644 index 000000000000..8458a6949c65 --- /dev/null +++ b/drivers/gpio/gpio-amdpt.c @@ -0,0 +1,147 @@ +// 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/gpio/generic.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_generic_chip chip; + void __iomem *reg_base; +}; + +static int pt_gpio_request(struct gpio_chip *gc, unsigned offset) +{ + struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc); + struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); + u32 using_pins; + + dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset); + + guard(gpio_generic_lock_irqsave)(gen_gc); + + 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); + return -EINVAL; + } + + writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG); + + return 0; +} + +static void pt_gpio_free(struct gpio_chip *gc, unsigned offset) +{ + struct gpio_generic_chip *gen_gc = to_gpio_generic_chip(gc); + struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); + u32 using_pins; + + guard(gpio_generic_lock_irqsave)(gen_gc); + + using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); + using_pins &= ~BIT(offset); + writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG); + + dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset); +} + +static int pt_gpio_probe(struct platform_device *pdev) +{ + struct gpio_generic_chip_config config; + 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); + } + + config = (struct gpio_generic_chip_config) { + .dev = dev, + .sz = 4, + .dat = pt_gpio->reg_base + PT_INPUTDATA_REG, + .set = pt_gpio->reg_base + PT_OUTPUTDATA_REG, + .dirout = pt_gpio->reg_base + PT_DIRECTION_REG, + .flags = GPIO_GENERIC_READ_OUTPUT_REG_SET, + }; + + ret = gpio_generic_chip_init(&pt_gpio->chip, &config); + if (ret) { + dev_err(dev, "failed to initialize the generic GPIO chip\n"); + return ret; + } + + pt_gpio->chip.gc.owner = THIS_MODULE; + pt_gpio->chip.gc.request = pt_gpio_request; + pt_gpio->chip.gc.free = pt_gpio_free; + pt_gpio->chip.gc.ngpio = (uintptr_t)device_get_match_data(dev); + + ret = devm_gpiochip_add_data(dev, &pt_gpio->chip.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 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, +}; + +module_platform_driver(pt_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>"); +MODULE_DESCRIPTION("AMD Promontory GPIO Driver"); |