x86: pcengines apuv2 gpio/leds/keys platform driver

Driver for PCengines APUv2 board's front LEDs and Button,
which are attached to AMD PCH GPIOs. Due to lack of dedicated
ACPI entry, detecting the board via DMI.

Cc: linux-gpio@vger.kernel.org
Cc: linus.walleij@linaro.org
Cc: bgolaszewski@baylibre.com
Cc: dvhart@infradead.org
Cc: platform-driver-x86@vger.kernel.org
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

MAINTAINERS

@@ -11522,6 +11522,11 @@ F:	lib/parman.c
 F:	lib/test_parman.c
 F:	include/linux/parman.h
 
+PC ENGINES APU BOARD DRIVER
+M:	Enrico Weigelt, metux IT consult <info@metux.net>
+S:	Maintained
+F:	drivers/platform/x86/pcengines-apuv2.c
+
 PC87360 HARDWARE MONITORING DRIVER
 M:	Jim Cromie <jim.cromie@gmail.com>
 L:	linux-hwmon@vger.kernel.org

drivers/platform/x86/Kconfig

@@ -1303,6 +1303,18 @@ config HUAWEI_WMI
 	  To compile this driver as a module, choose M here: the module
 	  will be called huawei-wmi.
 
+config PCENGINES_APU2
+	tristate "PC Engines APUv2/3 front button and LEDs driver"
+	select GPIO_AMD_FCH
+	select KEYBOARD_GPIO_POLLED
+	select LEDS_GPIO
+	help
+	  This driver provides support for the front button and LEDs on
+	  PC Engines APUv2/APUv3 board.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pcengines-apuv2.
+
 endif # X86_PLATFORM_DEVICES
 
 config PMC_ATOM

drivers/platform/x86/Makefile

@@ -96,3 +96,4 @@ obj-$(CONFIG_INTEL_TURBO_MAX_3) += intel_turbo_max_3.o
 obj-$(CONFIG_INTEL_CHTDC_TI_PWRBTN)	+= intel_chtdc_ti_pwrbtn.o
 obj-$(CONFIG_I2C_MULTI_INSTANTIATE)	+= i2c-multi-instantiate.o
 obj-$(CONFIG_INTEL_ATOMISP2_PM)	+= intel_atomisp2_pm.o
+obj-$(CONFIG_PCENGINES_APU2)	+= pcengines-apuv2.o

drivers/platform/x86/pcengines-apuv2.c

+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * PC-Engines APUv2/APUv3 board platform driver
+ * for gpio buttons and LEDs
+ *
+ * Copyright (C) 2018 metux IT consult
+ * Author: Enrico Weigelt <info@metux.net>
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/dmi.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/gpio_keys.h>
+#include <linux/gpio/machine.h>
+#include <linux/input.h>
+#include <linux/platform_data/gpio/gpio-amd-fch.h>
+
+/*
+ * NOTE: this driver only supports APUv2/3 - not APUv1, as this one
+ * has completely different register layouts
+ */
+
+/* register mappings */
+#define APU2_GPIO_REG_LED1		AMD_FCH_GPIO_REG_GPIO57
+#define APU2_GPIO_REG_LED2		AMD_FCH_GPIO_REG_GPIO58
+#define APU2_GPIO_REG_LED3		AMD_FCH_GPIO_REG_GPIO59_DEVSLP1
+#define APU2_GPIO_REG_MODESW		AMD_FCH_GPIO_REG_GPIO32_GE1
+#define APU2_GPIO_REG_SIMSWAP		AMD_FCH_GPIO_REG_GPIO33_GE2
+
+/* order in which the gpio lines are defined in the register list */
+#define APU2_GPIO_LINE_LED1		0
+#define APU2_GPIO_LINE_LED2		1
+#define APU2_GPIO_LINE_LED3		2
+#define APU2_GPIO_LINE_MODESW		3
+#define APU2_GPIO_LINE_SIMSWAP		4
+
+/* gpio device */
+
+static int apu2_gpio_regs[] = {
+	[APU2_GPIO_LINE_LED1]		= APU2_GPIO_REG_LED1,
+	[APU2_GPIO_LINE_LED2]		= APU2_GPIO_REG_LED2,
+	[APU2_GPIO_LINE_LED3]		= APU2_GPIO_REG_LED3,
+	[APU2_GPIO_LINE_MODESW]		= APU2_GPIO_REG_MODESW,
+	[APU2_GPIO_LINE_SIMSWAP]	= APU2_GPIO_REG_SIMSWAP,
+};
+
+static const char * const apu2_gpio_names[] = {
+	[APU2_GPIO_LINE_LED1]		= "front-led1",
+	[APU2_GPIO_LINE_LED2]		= "front-led2",
+	[APU2_GPIO_LINE_LED3]		= "front-led3",
+	[APU2_GPIO_LINE_MODESW]		= "front-button",
+	[APU2_GPIO_LINE_SIMSWAP]	= "simswap",
+};
+
+static const struct amd_fch_gpio_pdata board_apu2 = {
+	.gpio_num	= ARRAY_SIZE(apu2_gpio_regs),
+	.gpio_reg	= apu2_gpio_regs,
+	.gpio_names	= apu2_gpio_names,
+};
+
+/* gpio leds device */
+
+static const struct gpio_led apu2_leds[] = {
+	{ .name = "apu:green:1" },
+	{ .name = "apu:green:2" },
+	{ .name = "apu:green:3" }
+};
+
+static const struct gpio_led_platform_data apu2_leds_pdata = {
+	.num_leds	= ARRAY_SIZE(apu2_leds),
+	.leds		= apu2_leds,
+};
+
+struct gpiod_lookup_table gpios_led_table = {
+	.dev_id = "leds-gpio",
+	.table = {
+		GPIO_LOOKUP_IDX(AMD_FCH_GPIO_DRIVER_NAME, APU2_GPIO_LINE_LED1,
+				NULL, 0, GPIO_ACTIVE_LOW),
+		GPIO_LOOKUP_IDX(AMD_FCH_GPIO_DRIVER_NAME, APU2_GPIO_LINE_LED2,
+				NULL, 1, GPIO_ACTIVE_LOW),
+		GPIO_LOOKUP_IDX(AMD_FCH_GPIO_DRIVER_NAME, APU2_GPIO_LINE_LED3,
+				NULL, 2, GPIO_ACTIVE_LOW),
+	}
+};
+
+/* gpio keyboard device */
+
+static struct gpio_keys_button apu2_keys_buttons[] = {
+	{
+		.code			= KEY_SETUP,
+		.active_low		= 1,
+		.desc			= "front button",
+		.type			= EV_KEY,
+		.debounce_interval	= 10,
+		.value			= 1,
+	},
+};
+
+static const struct gpio_keys_platform_data apu2_keys_pdata = {
+	.buttons	= apu2_keys_buttons,
+	.nbuttons	= ARRAY_SIZE(apu2_keys_buttons),
+	.poll_interval	= 100,
+	.rep		= 0,
+	.name		= "apu2-keys",
+};
+
+struct gpiod_lookup_table gpios_key_table = {
+	.dev_id = "gpio-keys-polled",
+	.table = {
+		GPIO_LOOKUP_IDX(AMD_FCH_GPIO_DRIVER_NAME, APU2_GPIO_LINE_MODESW,
+				NULL, 0, GPIO_ACTIVE_LOW),
+	}
+};
+
+/* board setup */
+
+/* note: matching works on string prefix, so "apu2" must come before "apu" */
+static const struct dmi_system_id apu_gpio_dmi_table[] __initconst = {
+
+	/* APU2 w/ legacy bios < 4.0.8 */
+	{
+		.ident		= "apu2",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+			DMI_MATCH(DMI_BOARD_NAME, "APU2")
+		},
+		.driver_data	= (void *)&board_apu2,
+	},
+	/* APU2 w/ legacy bios >= 4.0.8 */
+	{
+		.ident		= "apu2",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+			DMI_MATCH(DMI_BOARD_NAME, "apu2")
+		},
+		.driver_data	= (void *)&board_apu2,
+	},
+	/* APU2 w/ maainline bios */
+	{
+		.ident		= "apu2",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+			DMI_MATCH(DMI_BOARD_NAME, "PC Engines apu2")
+		},
+		.driver_data	= (void *)&board_apu2,
+	},
+
+	/* APU3 w/ legacy bios < 4.0.8 */
+	{
+		.ident		= "apu3",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+			DMI_MATCH(DMI_BOARD_NAME, "APU3")
+		},
+		.driver_data = (void *)&board_apu2,
+	},
+	/* APU3 w/ legacy bios >= 4.0.8 */
+	{
+		.ident       = "apu3",
+		.matches     = {
+			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+			DMI_MATCH(DMI_BOARD_NAME, "apu3")
+		},
+		.driver_data = (void *)&board_apu2,
+	},
+	/* APU3 w/ mainline bios */
+	{
+		.ident       = "apu3",
+		.matches     = {
+			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
+			DMI_MATCH(DMI_BOARD_NAME, "PC Engines apu3")
+		},
+		.driver_data = (void *)&board_apu2,
+	},
+	{}
+};
+
+static struct platform_device *apu_gpio_pdev;
+static struct platform_device *apu_leds_pdev;
+static struct platform_device *apu_keys_pdev;
+
+static struct platform_device * __init apu_create_pdev(
+	const char *name,
+	const void *pdata,
+	size_t sz)
+{
+	struct platform_device *pdev;
+
+	pdev = platform_device_register_resndata(NULL,
+		name,
+		PLATFORM_DEVID_NONE,
+		NULL,
+		0,
+		pdata,
+		sz);
+
+	if (IS_ERR(pdev))
+		pr_err("failed registering %s: %ld\n", name, PTR_ERR(pdev));
+
+	return pdev;
+}
+
+static int __init apu_board_init(void)
+{
+	int rc;
+	const struct dmi_system_id *id;
+
+	id = dmi_first_match(apu_gpio_dmi_table);
+	if (!id) {
+		pr_err("failed to detect apu board via dmi\n");
+		return -ENODEV;
+	}
+
+	gpiod_add_lookup_table(&gpios_led_table);
+	gpiod_add_lookup_table(&gpios_key_table);
+
+	apu_gpio_pdev = apu_create_pdev(
+		AMD_FCH_GPIO_DRIVER_NAME,
+		id->driver_data,
+		sizeof(struct amd_fch_gpio_pdata));
+
+	apu_leds_pdev = apu_create_pdev(
+		"leds-gpio",
+		&apu2_leds_pdata,
+		sizeof(apu2_leds_pdata));
+
+	apu_keys_pdev = apu_create_pdev(
+		"gpio-keys-polled",
+		&apu2_keys_pdata,
+		sizeof(apu2_keys_pdata));
+
+	return 0;
+}
+
+static void __exit apu_board_exit(void)
+{
+	gpiod_remove_lookup_table(&gpios_led_table);
+	gpiod_remove_lookup_table(&gpios_key_table);
+
+	platform_device_unregister(apu_keys_pdev);
+	platform_device_unregister(apu_leds_pdev);
+	platform_device_unregister(apu_gpio_pdev);
+}
+
+module_init(apu_board_init);
+module_exit(apu_board_exit);
+
+MODULE_AUTHOR("Enrico Weigelt, metux IT consult <info@metux.net>");
+MODULE_DESCRIPTION("PC Engines APUv2/APUv3 board GPIO/LED/keys driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(dmi, apu_gpio_dmi_table);
+MODULE_ALIAS("platform:pcengines-apuv2");
+MODULE_SOFTDEP("pre: platform:" AMD_FCH_GPIO_DRIVER_NAME);
+MODULE_SOFTDEP("pre: platform:leds-gpio");
+MODULE_SOFTDEP("pre: platform:gpio_keys_polled");