leds-apu2: Add PC Engines APU2 LED driver

This adds support for the PCB LEDs and Reset Button found on the PC
Engines APU2/APU3 embedded boards.

Signed-off-by: Chris Blake <[email protected]>

package/kernel/leds-apu2/Makefile

@@ -0,0 +1,52 @@
+#
+# Copyright (C) 2017 Chris Blake <[email protected]>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=leds-apu2
+PKG_RELEASE:=1
+
+PKG_MAINTAINER:=Chris Blake <[email protected]>
+PKG_LICENSE:=GPL-2.0
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/leds-apu2
+  SUBMENU:=LED modules
+  TITLE:= PC Engines APU2/APU3 LED support
+  DEPENDS:= @GPIO_SUPPORT @TARGET_x86
+  FILES:=$(PKG_BUILD_DIR)/leds-apu2.ko
+  AUTOLOAD:=$(call AutoLoad,41,leds-apu2,1)
+  KCONFIG:=
+endef
+
+define KernelPackage/leds-apu2/description
+  Driver for the PC Engines APU2/APU3 LEDs & Reset Button.
+endef
+
+EXTRA_KCONFIG:= \
+	CONFIG_LEDS_APU2=m
+
+EXTRA_CFLAGS:= \
+	$(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=m,%,$(filter %=m,$(EXTRA_KCONFIG)))) \
+	$(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=y,%,$(filter %=y,$(EXTRA_KCONFIG)))) \
+
+MAKE_OPTS:= \
+	ARCH="$(LINUX_KARCH)" \
+	CROSS_COMPILE="$(TARGET_CROSS)" \
+	SUBDIRS="$(PKG_BUILD_DIR)" \
+	EXTRA_CFLAGS="$(EXTRA_CFLAGS)" \
+	$(EXTRA_KCONFIG)
+
+define Build/Compile
+	 $(MAKE) -C "$(LINUX_DIR)" \
+		$(MAKE_OPTS) \
+		modules
+endef
+
+$(eval $(call KernelPackage,leds-apu2))

package/kernel/leds-apu2/src/Kconfig

@@ -0,0 +1,8 @@
+config LEDS_APU2
+        tristate "PC Engines APU2/APU3 LED support"
+        depends on LEDS_CLASS
+        depends on LEDS_GPIO
+        depends on GPIOLIB
+        help
+          Say yes here to enable support for the CPU GPIO pins on the PC Engines
+          APU2/APU3 board, which enables the front LEDs and Reset Button.

package/kernel/leds-apu2/src/Makefile

@@ -0,0 +1 @@
+obj-${CONFIG_LEDS_APU2}    += leds-apu2.o

package/kernel/leds-apu2/src/leds-apu2.c

@@ -0,0 +1,374 @@
+/*
+*  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;
+		}
+	}
+
+	gpio_apu2_chip.dev = &dev->dev;
+	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:power",
+                .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: 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);