leds: Add driver for PC Engines APU/APU2 LEDs

This patch implements the driver to support the front panel LEDs
for PC Engines APU and APU2 boards.

Signed-off-by: Alan Mizrahi <alan@mizrahi.com.ve>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

3 files changed, 289 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 52ea34e337cd..318a28fd58fe 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -57,6 +57,16 @@ config LEDS_AAT1290
         depends on PINCTRL
         help
          This option enables support for the LEDs on the AAT1290.
+config LEDS_APU
+        tristate "Front panel LED support for PC Engines APU/APU2 boards"
+        depends on LEDS_CLASS
+        depends on X86 && DMI
+        help
+          This driver makes the PC Engines APU/APU2 front panel LEDs
+          accessible from userspace programs through the LED subsystem.
+
+          To compile this driver as a module, choose M here: the
+          module will be called leds-apu.
 
 config LEDS_AS3645A
         tristate "AS3645A LED flash controller support"
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 7d7b26552923..6de49790255e 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_LEDS_TRIGGERS)		+= led-triggers.o
 # LED Platform Drivers
 obj-$(CONFIG_LEDS_88PM860X)             += leds-88pm860x.o
 obj-$(CONFIG_LEDS_AAT1290)              += leds-aat1290.o
+obj-$(CONFIG_LEDS_APU)                  += leds-apu.o
 obj-$(CONFIG_LEDS_AS3645A)              += leds-as3645a.o
 obj-$(CONFIG_LEDS_BCM6328)              += leds-bcm6328.o
 obj-$(CONFIG_LEDS_BCM6358)              += leds-bcm6358.o
diff --git a/drivers/leds/leds-apu.c b/drivers/leds/leds-apu.c
new file mode 100644
index 000000000000..74820aab9497
--- /dev/null
+++ b/drivers/leds/leds-apu.c
@@ -0,0 +1,278 @@
+/*
+ * drivers/leds/leds-apu.c
+ * Copyright (C) 2017 Alan Mizrahi, alan at mizrahi dot com dot ve
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/dmi.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define APU1_FCH_ACPI_MMIO_BASE 0xFED80000
+#define APU1_FCH_GPIO_BASE      (APU1_FCH_ACPI_MMIO_BASE + 0x01BD)
+#define APU1_LEDON              0x08
+#define APU1_LEDOFF             0xC8
+#define APU1_NUM_GPIO           3
+#define APU1_IOSIZE             sizeof(u8)
+
+#define APU2_FCH_ACPI_MMIO_BASE 0xFED80000
+#define APU2_FCH_GPIO_BASE      (APU2_FCH_ACPI_MMIO_BASE + 0x1500)
+#define APU2_GPIO_BIT_WRITE     22
+#define APU2_APU2_NUM_GPIO      4
+#define APU2_IOSIZE             sizeof(u32)
+
+/* LED access parameters */
+struct apu_param {
+        void __iomem *addr; /* for ioread/iowrite */
+};
+
+/* LED private data */
+struct apu_led_priv {
+        struct led_classdev cdev;
+        struct apu_param param;
+};
+#define cdev_to_priv(c) container_of(c, struct apu_led_priv, cdev)
+
+/* LED profile */
+struct apu_led_profile {
+        const char *name;
+        enum led_brightness brightness;
+        unsigned long offset; /* for devm_ioremap */
+};
+
+/* Supported platform types */
+enum apu_led_platform_types {
+        APU1_LED_PLATFORM,
+        APU2_LED_PLATFORM,
+};
+
+struct apu_led_pdata {
+        struct platform_device *pdev;
+        struct apu_led_priv *pled;
+        const struct apu_led_profile *profile;
+        enum apu_led_platform_types platform;
+        int num_led_instances;
+        int iosize; /* for devm_ioremap() */
+        spinlock_t lock;
+};
+
+static struct apu_led_pdata *apu_led;
+
+static const struct apu_led_profile apu1_led_profile[] = {
+        { "apu:green:1", LED_ON,  APU1_FCH_GPIO_BASE + 0 * APU1_IOSIZE },
+        { "apu:green:2", LED_OFF, APU1_FCH_GPIO_BASE + 1 * APU1_IOSIZE },
+        { "apu:green:3", LED_OFF, APU1_FCH_GPIO_BASE + 2 * APU1_IOSIZE },
+};
+
+static const struct apu_led_profile apu2_led_profile[] = {
+        { "apu2:green:1", LED_ON,  APU2_FCH_GPIO_BASE + 68 * APU2_IOSIZE },
+        { "apu2:green:2", LED_OFF, APU2_FCH_GPIO_BASE + 69 * APU2_IOSIZE },
+        { "apu2:green:3", LED_OFF, APU2_FCH_GPIO_BASE + 70 * APU2_IOSIZE },
+};
+
+static const struct dmi_system_id apu_led_dmi_table[] __initconst = {
+        {
+                .ident = "apu",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "APU")
+                }
+        },
+        {
+                .ident = "apu2",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+                        DMI_MATCH(DMI_BOARD_NAME, "APU2")
+                }
+        },
+        {}
+};
+MODULE_DEVICE_TABLE(dmi, apu_led_dmi_table);
+
+static void apu1_led_brightness_set(struct led_classdev *led, enum led_brightness value)
+{
+        struct apu_led_priv *pled = cdev_to_priv(led);
+
+        spin_lock(&apu_led->lock);
+        iowrite8(value ? APU1_LEDON : APU1_LEDOFF, pled->param.addr);
+        spin_unlock(&apu_led->lock);
+}
+
+static void apu2_led_brightness_set(struct led_classdev *led, enum led_brightness value)
+{
+        struct apu_led_priv *pled = cdev_to_priv(led);
+        u32 value_new;
+
+        spin_lock(&apu_led->lock);
+
+        value_new = ioread32(pled->param.addr);
+
+        if (value)
+                value_new &= ~BIT(APU2_GPIO_BIT_WRITE);
+        else
+                value_new |= BIT(APU2_GPIO_BIT_WRITE);
+
+        iowrite32(value_new, pled->param.addr);
+
+        spin_unlock(&apu_led->lock);
+}
+
+static int apu_led_config(struct device *dev, struct apu_led_pdata *apuld)
+{
+        int i;
+        int err;
+
+        apu_led->pled = devm_kzalloc(dev,
+                sizeof(struct apu_led_priv) * apu_led->num_led_instances,
+                GFP_KERNEL);
+
+        if (!apu_led->pled)
+                return -ENOMEM;
+
+        for (i = 0; i < apu_led->num_led_instances; i++) {
+                struct apu_led_priv *pled = &apu_led->pled[i];
+                struct led_classdev *led_cdev = &pled->cdev;
+
+                led_cdev->name = apu_led->profile[i].name;
+                led_cdev->brightness = apu_led->profile[i].brightness;
+                led_cdev->max_brightness = 1;
+                led_cdev->flags = LED_CORE_SUSPENDRESUME;
+                if (apu_led->platform == APU1_LED_PLATFORM)
+                        led_cdev->brightness_set = apu1_led_brightness_set;
+                else if (apu_led->platform == APU2_LED_PLATFORM)
+                        led_cdev->brightness_set = apu2_led_brightness_set;
+
+                pled->param.addr = devm_ioremap(dev,
+                                apu_led->profile[i].offset, apu_led->iosize);
+                if (!pled->param.addr) {
+                        err = -ENOMEM;
+                        goto error;
+                }
+
+                err = led_classdev_register(dev, led_cdev);
+                if (err)
+                        goto error;
+
+                led_cdev->brightness_set(led_cdev, apu_led->profile[i].brightness);
+        }
+
+        return 0;
+
+error:
+        while (i-- > 0)
+                led_classdev_unregister(&apu_led->pled[i].cdev);
+
+        return err;
+}
+
+static int __init apu_led_probe(struct platform_device *pdev)
+{
+        apu_led = devm_kzalloc(&pdev->dev, sizeof(*apu_led), GFP_KERNEL);
+
+        if (!apu_led)
+                return -ENOMEM;
+
+        apu_led->pdev = pdev;
+
+        if (dmi_match(DMI_BOARD_NAME, "APU")) {
+                apu_led->profile = apu1_led_profile;
+                apu_led->platform = APU1_LED_PLATFORM;
+                apu_led->num_led_instances = ARRAY_SIZE(apu1_led_profile);
+                apu_led->iosize = APU1_IOSIZE;
+        } else if (dmi_match(DMI_BOARD_NAME, "APU2")) {
+                apu_led->profile = apu2_led_profile;
+                apu_led->platform = APU2_LED_PLATFORM;
+                apu_led->num_led_instances = ARRAY_SIZE(apu2_led_profile);
+                apu_led->iosize = APU2_IOSIZE;
+        }
+
+        spin_lock_init(&apu_led->lock);
+        return apu_led_config(&pdev->dev, apu_led);
+}
+
+static struct platform_driver apu_led_driver = {
+        .driver = {
+                .name = KBUILD_MODNAME,
+        },
+};
+
+static int __init apu_led_init(void)
+{
+        struct platform_device *pdev;
+        int err;
+
+        if (!dmi_match(DMI_SYS_VENDOR, "PC Engines")) {
+                pr_err("No PC Engines board detected\n");
+                return -ENODEV;
+        }
+        if (!(dmi_match(DMI_PRODUCT_NAME, "APU") || dmi_match(DMI_PRODUCT_NAME, "APU2"))) {
+                pr_err("Unknown PC Engines board: %s\n",
+                                dmi_get_system_info(DMI_PRODUCT_NAME));
+                return -ENODEV;
+        }
+
+        pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
+        if (IS_ERR(pdev)) {
+                pr_err("Device allocation failed\n");
+                return PTR_ERR(pdev);
+        }
+
+        err = platform_driver_probe(&apu_led_driver, apu_led_probe);
+        if (err) {
+                pr_err("Probe platform driver failed\n");
+                platform_device_unregister(pdev);
+        }
+
+        return err;
+}
+
+static void __exit apu_led_exit(void)
+{
+        int i;
+
+        for (i = 0; i < apu_led->num_led_instances; i++)
+                led_classdev_unregister(&apu_led->pled[i].cdev);
+
+        platform_device_unregister(apu_led->pdev);
+        platform_driver_unregister(&apu_led_driver);
+}
+
+module_init(apu_led_init);
+module_exit(apu_led_exit);
+
+MODULE_AUTHOR("Alan Mizrahi");
+MODULE_DESCRIPTION("PC Engines APU family LED driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:leds_apu");