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/*
* Virtual GPIO controller driver
* Copyright (c) 2014, Intel Corporation.
*
* Author: Dyut Kumar Sil <dyut.k.sil@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/irq.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/workqueue.h>
#define VIRTUAL_GPIO_DRIVER_VERSION "1.1.0"
#define VIRTUAL_GPIO_DRIVER_NAME "virtual_gpio"
#define GPE0A_PME_STS_BIT 0x2000
#define GPE0A_PME_EN_BIT 0x2000
#define GPE0A_STS_PORT 0x420
#define GPE0A_EN_PORT 0x428
#define BYT_MODEL 0x37
struct workqueue_struct *vgpio_wq;
struct virtual_gpio_data {
int irq;
struct platform_device *pdev;
struct work_struct periodic_work;
struct mutex vg_mutex;
};
static irqreturn_t virtual_gpio_irq_handler(int irq, void *data)
{
struct virtual_gpio_data *gd;
gd = data;
queue_work(vgpio_wq, &gd->periodic_work);
return IRQ_HANDLED;
}
void virtual_gpio_irq_handler_isr(struct work_struct *work)
{
u32 gpe_sts_reg = inl(GPE0A_STS_PORT);
u32 gpe_en_reg = inl(GPE0A_EN_PORT), temp = 0;
acpi_status status;
u64 tmp;
acpi_handle handle;
struct virtual_gpio_data *gd =
container_of(work, struct virtual_gpio_data, periodic_work);
struct device *dev = &gd->pdev->dev;
handle = ACPI_HANDLE(dev);
if (!handle)
return;
mutex_lock(&gd->vg_mutex);
if (gpe_en_reg & GPE0A_PME_EN_BIT) {
/* Clear the STS Bit */
temp = gpe_en_reg&(~GPE0A_PME_EN_BIT);
outl(temp, GPE0A_EN_PORT);
}
if (boot_cpu_data.x86_model != BYT_MODEL) {
status = acpi_evaluate_object(handle,
"_E02", NULL, NULL);
if (ACPI_FAILURE(status))
dev_err(dev, "_E02 call failed in virtual gpio\n");
}
if (gpe_sts_reg & GPE0A_PME_STS_BIT)
outl(GPE0A_PME_STS_BIT, GPE0A_STS_PORT);
if (gpe_en_reg & GPE0A_PME_EN_BIT)
outl(gpe_en_reg, GPE0A_EN_PORT);
mutex_unlock(&gd->vg_mutex);
return;
}
static void acpi_virtual_gpio_request_interrupts(struct virtual_gpio_data *gd)
{
struct device *dev = &gd->pdev->dev;
struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
struct acpi_resource *res;
acpi_handle handle, ev_handle;
acpi_status status;
unsigned int pin;
int ret;
char ev_name[5];
unsigned long irq_flags;
handle = ACPI_HANDLE(dev);
if (!handle)
return;
status = acpi_get_event_resources(handle, &buf);
if (ACPI_FAILURE(status)) {
if (buf.pointer)
ACPI_FREE(buf.pointer);
return;
}
/*
* If a GPIO interrupt has an ACPI event handler method, set
* up an interrupt handler that calls the ACPI event handler.
*/
for (res = buf.pointer;
res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
res = ACPI_NEXT_RESOURCE(res)) {
if (res->type != ACPI_RESOURCE_TYPE_GPIO ||
res->data.gpio.connection_type !=
ACPI_RESOURCE_GPIO_TYPE_INT)
continue;
pin = res->data.gpio.pin_table[0];
dev_info(dev, "virtual gpio pin = %d\n", pin);
if (pin > 255)
continue;
sprintf(ev_name, "_%c%02X",
res->data.gpio.triggering ? 'E' : 'L', pin);
status = acpi_get_handle(handle, ev_name, &ev_handle);
if (ACPI_FAILURE(status))
continue;
irq_flags = IRQF_SHARED | IRQF_NO_SUSPEND;
if (acpi_gbl_reduced_hardware)
irq_flags = 0;
ret = devm_request_irq(dev, gd->irq,
virtual_gpio_irq_handler,
irq_flags,
VIRTUAL_GPIO_DRIVER_NAME,
gd);
if (ret)
dev_err(dev,
"Failed to request IRQ %d ACPI event handler\n",
gd->irq);
}
if (buf.pointer)
ACPI_FREE(buf.pointer);
}
static int virtual_gpio_probe(struct platform_device *pdev)
{
struct virtual_gpio_data *gd;
struct device *dev = &pdev->dev;
u32 gpe_en_reg = inl(GPE0A_EN_PORT);
u32 ret = 0;
gd = devm_kzalloc(dev, sizeof(struct virtual_gpio_data), GFP_KERNEL);
if (!gd) {
dev_err(dev, "can't allocate memory for virtual_gpio\n");
return -ENOMEM;
}
gd->pdev = pdev;
platform_set_drvdata(pdev, gd);
/* set up interrupt */
gd->irq = platform_get_irq(pdev, 0);
INIT_WORK(&gd->periodic_work, virtual_gpio_irq_handler_isr);
vgpio_wq = create_singlethread_workqueue(dev_name(dev));
if (!vgpio_wq) {
dev_err(dev, "virtual gpio worker thread create failed\n");
ret = -ENOMEM;
return ret;
}
acpi_virtual_gpio_request_interrupts(gd);
mutex_init(&gd->vg_mutex);
pm_runtime_enable(dev);
gpe_en_reg |= GPE0A_PME_EN_BIT;
outl(gpe_en_reg, GPE0A_EN_PORT);
return ret;
}
static int virtual_gpio_runtime_suspend(struct device *dev)
{
return 0;
}
static int virtual_gpio_runtime_resume(struct device *dev)
{
return 0;
}
static const struct dev_pm_ops virtual_gpio_pm_ops = {
.runtime_suspend = virtual_gpio_runtime_suspend,
.runtime_resume = virtual_gpio_runtime_resume,
};
static const struct acpi_device_id virtual_gpio_acpi_ids[] = {
{ "INT0002", 0 },
{ },
};
MODULE_DEVICE_TABLE(acpi, virtual_gpio_acpi_ids);
static int virtual_gpio_remove(struct platform_device *pdev)
{
destroy_workqueue(vgpio_wq);
platform_set_drvdata(pdev, NULL);
return 0;
}
static void virtual_gpio_shutdown(struct platform_device *pdev)
{
}
static struct platform_driver virtual_gpio_driver = {
.driver = {
.name = VIRTUAL_GPIO_DRIVER_NAME,
.owner = THIS_MODULE,
.pm = &virtual_gpio_pm_ops,
.acpi_match_table = ACPI_PTR(virtual_gpio_acpi_ids),
},
.probe = virtual_gpio_probe,
.remove = virtual_gpio_remove,
.shutdown = virtual_gpio_shutdown,
};
module_platform_driver(virtual_gpio_driver);
MODULE_AUTHOR("Dyut Kumar Sil <dyut.k.sil@intel.com>");
MODULE_DESCRIPTION("Intel (R) Virtual GPIO Controller Driver");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(VIRTUAL_GPIO_DRIVER_VERSION);
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