/*

* APU2 LED/GPIO Driver

* Copyright (c) 2016 Christian Lamparter <chunkeey (at) googlemail.com>

*

* Based on gpio-apu2.c - AMD FCH GPIO support for PC-Engines APU-2 board

*

* Copyright (c) 2015 Carsten Spiess <fli4l at carsten-spiess.de>

*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that 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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <linux/module.h>

#include <linux/types.h>

#include <linux/miscdevice.h>

#include <linux/gpio.h>

#include <linux/init.h>

#include <linux/pci.h>

#include <linux/ioport.h>

#include <linux/platform_device.h>

#include <linux/uaccess.h>

#include <linux/io.h>

#include <linux/version.h>

#include <linux/dmi.h>

#include <linux/string.h>

#include <linux/leds.h>

#include <linux/input.h>

#include <linux/gpio_keys.h>

#define DEVNAME "leds-apu2"

#define FCH_ACPI_MMIO_BASE 0xFED80000

#define FCH_GPIO_BASE (FCH_ACPI_MMIO_BASE + 0x1500)

#define FCH_GPIO_SIZE 0x300

#define APU_NUM_GPIO 4

#define GPIO_BIT_DIR 23

#define GPIO_BIT_WRITE 22

#define GPIO_BIT_READ 16

/* internal variables */

static struct pci_dev *gpio_apu2_pci;

static DEFINE_SPINLOCK (gpio_lock);

/* the watchdog platform device */

static struct platform_device *gpio_apu2_platform_device;

static struct platform_device *leddev;

static struct platform_device *keydev;

static const struct pci_device_id gpio_apu2_pci_tbl[] ={

{PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID, PCI_ANY_ID},

{ 0, } /* End of list */

};

MODULE_DEVICE_TABLE (pci, gpio_apu2_pci_tbl);

/* EGPIO89=GPIO32, AGPIO68=GPIO57, AGPIO69=GPIO58, AGPIO70=GPIO59 */

static u8 gpio_offset[APU_NUM_GPIO] = {89, 68, 69, 70};

static void __iomem *gpio_addr[APU_NUM_GPIO] = {NULL, NULL, NULL, NULL};

static int gpio_apu2_get_dir (struct gpio_chip *chip, unsigned offset)

{

u32 val;

val = ~ioread32 (gpio_addr[offset]);

return (val >> GPIO_BIT_DIR) & 1;

}

static int gpio_apu2_dir_in (struct gpio_chip *gc, unsigned offset)

{

u32 val;

spin_lock_bh (&gpio_lock);

val = ioread32 (gpio_addr[offset]);

val &= ~BIT(GPIO_BIT_DIR);

iowrite32 (val, gpio_addr[offset]);

spin_unlock_bh (&gpio_lock);

return 0;

}

static int gpio_apu2_dir_out (struct gpio_chip *chip, unsigned offset,

int value)

{

u32 val;

spin_lock_bh (&gpio_lock);

val = ioread32 (gpio_addr[offset]);

val |= BIT(GPIO_BIT_DIR);

iowrite32 (val, gpio_addr[offset]);

spin_unlock_bh (&gpio_lock);

return 0;

}

static int gpio_apu2_get_data (struct gpio_chip *chip, unsigned offset)

{

u32 val;

val = ioread32 (gpio_addr[offset]);

return (val >> GPIO_BIT_READ) & 1;

}

static void gpio_apu2_set_data (struct gpio_chip *chip, unsigned offset, int value)

{

u32 val;

spin_lock_bh (&gpio_lock);

val = ioread32 (gpio_addr[offset]);

if (value)

val |= BIT(GPIO_BIT_WRITE);

else

val &= ~BIT(GPIO_BIT_WRITE);

iowrite32 (val, gpio_addr[offset]);

spin_unlock_bh (&gpio_lock);

}

static struct gpio_chip gpio_apu2_chip = {

.label = DEVNAME,

.owner = THIS_MODULE,

.base = -1,

.ngpio = APU_NUM_GPIO,

.get_direction = gpio_apu2_get_dir,

.direction_input = gpio_apu2_dir_in,

.direction_output = gpio_apu2_dir_out,

.get = gpio_apu2_get_data,

.set = gpio_apu2_set_data,

};

/*

*

*/

static int gpio_apu2_probe (struct platform_device *dev)

{

int ret = 0;

int i;

struct pci_dev *pci_dev = NULL;

/* Match the PCI device */

for_each_pci_dev (pci_dev) {

if (pci_match_id (gpio_apu2_pci_tbl, pci_dev) != NULL) {

gpio_apu2_pci = pci_dev;

break;

}

}

if (!gpio_apu2_pci)

return -ENODEV;

pr_info ("%s: PCI Revision ID: 0x%x\n", DEVNAME, gpio_apu2_pci->revision);

/* Determine type of southbridge chipset */

if (gpio_apu2_pci->revision < 0x40) {

return -EACCES;

}

/* Request memory region for GPIO's */

if (!devm_request_mem_region (&dev->dev, FCH_GPIO_BASE,

FCH_GPIO_SIZE, DEVNAME)){

pr_err ("%s: request GPIO mem region failed\n", DEVNAME);

return -ENXIO;

}

/* Map IO's for GPIO's */

for (i = 0; i < APU_NUM_GPIO; i++) {

gpio_addr[i] = devm_ioremap (&dev->dev,

FCH_GPIO_BASE + (gpio_offset[i] * sizeof (u32)), sizeof (u32));

if (!gpio_addr[i]) {

pr_err ("%s: map GPIO%d address failed\n", DEVNAME, gpio_offset[i]);

return -ENXIO;

}

}

#if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)

gpio_apu2_chip.dev = &dev->dev;

#else

gpio_apu2_chip.parent = &dev->dev;

#endif

ret = gpiochip_add (&gpio_apu2_chip);

if (ret) {

pr_err ("%s: adding gpiochip failed\n", DEVNAME);

}

return ret;

}

static int gpio_apu2_remove (struct platform_device *dev)

{

#if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)

int ret;

ret = gpiochip_remove (&gpio_apu2_chip);

#else /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */

gpiochip_remove (&gpio_apu2_chip);

#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */

return 0;

}

static struct platform_driver gpio_apu2_driver = {

.probe = gpio_apu2_probe,

.remove = gpio_apu2_remove,

.driver = {

.owner = THIS_MODULE,

.name = DEVNAME

}

};

static struct gpio_led apu2_leds_gpio[] = {

{

.name = "apu2:green:led1",

.gpio = 509,

.active_low = 1,

},

{

.name = "apu2:green:led2",

.gpio = 510,

.active_low = 1,

},

{

.name = "apu2:green:led3",

.gpio = 511,

.active_low = 1,

},

};

static struct gpio_keys_button apu2_gpio_keys[] = {

{

.desc = "Reset button",

.type = EV_KEY,

.code = KEY_RESTART,

.debounce_interval = 60,

.gpio = 508,

.active_low = 1,

},

};

static void register_gpio_keys_polled(int id, unsigned poll_interval,

unsigned nbuttons,

struct gpio_keys_button *buttons)

{

struct gpio_keys_platform_data pdata = { };

int err;

keydev = platform_device_alloc("gpio-keys-polled", id);

if (!keydev) {

printk(KERN_ERR "Failed to allocate gpio-keys platform device\n");

return;

}

pdata.poll_interval = poll_interval;

pdata.nbuttons = nbuttons;

pdata.buttons = buttons;

err = platform_device_add_data(keydev, &pdata, sizeof(pdata));

if (err) {

dev_err(&keydev->dev, "failed to add platform data to key driver (%d)", err);

goto err_put_pdev;

}

err = platform_device_add(keydev);

if (err) {

dev_err(&keydev->dev, "failed to register key platform device (%d)", err);

goto err_put_pdev;

}

return;

err_put_pdev:

platform_device_put(keydev);

keydev = NULL;

}

static void register_leds_gpio(int id, unsigned num_leds, struct gpio_led *leds)

{

struct gpio_led_platform_data pdata = { };

int err;

leddev = platform_device_alloc("leds-gpio", id);

if (!leddev) {

printk(KERN_ERR "Failed to allocate leds-gpio platform device\n");

return;

}

pdata.num_leds = num_leds;

pdata.leds = leds;

err = platform_device_add_data(leddev, &pdata, sizeof(pdata));

if (err) {

dev_err(&leddev->dev, "failed to add platform data to key driver (%d)", err);

goto err_put_pdev;

}

err = platform_device_add(leddev);

if (err) {

dev_err(&leddev->dev, "failed to register key platform device (%d)", err);

goto err_put_pdev;

}

return;

err_put_pdev:

platform_device_put(leddev);

leddev = NULL;

}

static int __init gpio_apu2_init (void)

{

int err;

const char *board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);

const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);

/* Match the device name/model */

if (!board_name || !board_vendor || strcasecmp(board_vendor, "PC Engines") || strcasecmp(board_name, "apu2")) {

err = -ENODEV;

goto exit;

}

pr_info ("%s: request GPIO LED driver module\n", DEVNAME);

if (request_module("leds-gpio")) {

err = -ENODEV;

goto exit;

}

pr_info ("%s: request Polled GPIO Buttons driver module\n", DEVNAME);

if (request_module("gpio-keys-polled")) {

err = -ENODEV;

goto exit;

}

pr_info ("%s: load APU2/LED GPIO driver module\n", DEVNAME);

err = platform_driver_register (&gpio_apu2_driver);

if (err)

goto exit;

gpio_apu2_platform_device = platform_device_register_simple (DEVNAME, -1, NULL, 0);

if (IS_ERR(gpio_apu2_platform_device)) {

err = PTR_ERR(gpio_apu2_platform_device);

goto exit_driver;

}

pr_info ("%s: APU2 GPIO/LED driver module loaded\n", DEVNAME);

register_leds_gpio(-1, ARRAY_SIZE(apu2_leds_gpio), apu2_leds_gpio);

register_gpio_keys_polled(-1, 20, ARRAY_SIZE(apu2_gpio_keys), apu2_gpio_keys);

return 0;

exit_driver:

platform_driver_unregister (&gpio_apu2_driver);

exit:

return err;

}

static void __exit gpio_apu2_exit (void)

{

platform_device_unregister (gpio_apu2_platform_device);

platform_device_unregister (leddev);

platform_device_unregister (keydev);

platform_driver_unregister (&gpio_apu2_driver);

pr_info ("%s: APU2 GPIO/LED driver module unloaded\n", DEVNAME);

}

MODULE_AUTHOR ("Carsten Spiess <fli4l at carsten-spiess.de>");

MODULE_DESCRIPTION("GPIO driver for AMD FCH on PC-Engines APU-2");

MODULE_LICENSE("GPL");

module_init (gpio_apu2_init);

module_exit (gpio_apu2_exit);