ACPI: add AMD ACPI2Platform device support for x86 system

This new feature is to interpret AMD specific ACPI device to
platform device such as I2C, UART, GPIO found on AMD CZ and
later chipsets. It based on example intel LPSS. Now, it can
support AMD I2C, UART and GPIO.

Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

arch/x86/Kconfig

@@ -496,6 +496,17 @@ config X86_INTEL_LPSS
 	  things like clock tree (common clock framework) and pincontrol
 	  which are needed by the LPSS peripheral drivers.
 
+config X86_AMD_PLATFORM_DEVICE
+	bool "AMD ACPI2Platform devices support"
+	depends on ACPI
+	select COMMON_CLK
+	select PINCTRL
+	---help---
+	  Select to interpret AMD specific ACPI device to platform device
+	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
+	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
+	  implemented under PINCTRL subsystem.
+
 config IOSF_MBI
 	tristate "Intel SoC IOSF Sideband support for SoC platforms"
 	depends on PCI

drivers/acpi/Makefile

@@ -40,7 +40,7 @@ acpi-$(CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC) += processor_pdc.o
 acpi-y				+= ec.o
 acpi-$(CONFIG_ACPI_DOCK)	+= dock.o
 acpi-y				+= pci_root.o pci_link.o pci_irq.o
-acpi-y				+= acpi_lpss.o
+acpi-y				+= acpi_lpss.o acpi_apd.o
 acpi-y				+= acpi_platform.o
 acpi-y				+= acpi_pnp.o
 acpi-y				+= int340x_thermal.o

drivers/acpi/acpi_apd.c

@@ -0,0 +1,150 @@
+/*
+ * AMD ACPI support for ACPI2platform device.
+ *
+ * Copyright (c) 2014,2015 AMD Corporation.
+ * Authors: Ken Xue <Ken.Xue@amd.com>
+ *	Wu, Jeff <Jeff.Wu@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/clkdev.h>
+#include <linux/acpi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/pm.h>
+
+#include "internal.h"
+
+ACPI_MODULE_NAME("acpi_apd");
+struct apd_private_data;
+
+/**
+ * ACPI_APD_SYSFS : add device attributes in sysfs
+ * ACPI_APD_PM : attach power domain to device
+ */
+#define ACPI_APD_SYSFS	BIT(0)
+#define ACPI_APD_PM	BIT(1)
+
+/**
+ * struct apd_device_desc - a descriptor for apd device
+ * @flags: device flags like %ACPI_APD_SYSFS, %ACPI_APD_PM
+ * @fixed_clk_rate: fixed rate input clock source for acpi device;
+ *			0 means no fixed rate input clock source
+ * @setup: a hook routine to set device resource during create platform device
+ *
+ * Device description defined as acpi_device_id.driver_data
+ */
+struct apd_device_desc {
+	unsigned int flags;
+	unsigned int fixed_clk_rate;
+	int (*setup)(struct apd_private_data *pdata);
+};
+
+struct apd_private_data {
+	struct clk *clk;
+	struct acpi_device *adev;
+	const struct apd_device_desc *dev_desc;
+};
+
+#ifdef CONFIG_X86_AMD_PLATFORM_DEVICE
+#define APD_ADDR(desc)	((unsigned long)&desc)
+
+static int acpi_apd_setup(struct apd_private_data *pdata)
+{
+	const struct apd_device_desc *dev_desc = pdata->dev_desc;
+	struct clk *clk = ERR_PTR(-ENODEV);
+
+	if (dev_desc->fixed_clk_rate) {
+		clk = clk_register_fixed_rate(&pdata->adev->dev,
+					dev_name(&pdata->adev->dev),
+					NULL, CLK_IS_ROOT,
+					dev_desc->fixed_clk_rate);
+		clk_register_clkdev(clk, NULL, dev_name(&pdata->adev->dev));
+		pdata->clk = clk;
+	}
+
+	return 0;
+}
+
+static struct apd_device_desc cz_i2c_desc = {
+	.setup = acpi_apd_setup,
+	.fixed_clk_rate = 133000000,
+};
+
+static struct apd_device_desc cz_uart_desc = {
+	.setup = acpi_apd_setup,
+	.fixed_clk_rate = 48000000,
+};
+
+#else
+
+#define APD_ADDR(desc) (0UL)
+
+#endif /* CONFIG_X86_AMD_PLATFORM_DEVICE */
+
+/**
+* Create platform device during acpi scan attach handle.
+* Return value > 0 on success of creating device.
+*/
+static int acpi_apd_create_device(struct acpi_device *adev,
+				   const struct acpi_device_id *id)
+{
+	const struct apd_device_desc *dev_desc = (void *)id->driver_data;
+	struct apd_private_data *pdata;
+	struct platform_device *pdev;
+	int ret;
+
+	if (!dev_desc) {
+		pdev = acpi_create_platform_device(adev);
+		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
+	}
+
+	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	pdata->adev = adev;
+	pdata->dev_desc = dev_desc;
+
+	if (dev_desc->setup) {
+		ret = dev_desc->setup(pdata);
+		if (ret)
+			goto err_out;
+	}
+
+	adev->driver_data = pdata;
+	pdev = acpi_create_platform_device(adev);
+	if (!IS_ERR_OR_NULL(pdev))
+		return 1;
+
+	ret = PTR_ERR(pdev);
+	adev->driver_data = NULL;
+
+ err_out:
+	kfree(pdata);
+	return ret;
+}
+
+static const struct acpi_device_id acpi_apd_device_ids[] = {
+	/* Generic apd devices */
+	{ "AMD0010", APD_ADDR(cz_i2c_desc) },
+	{ "AMD0020", APD_ADDR(cz_uart_desc) },
+	{ "AMD0030", },
+	{ }
+};
+
+static struct acpi_scan_handler apd_handler = {
+	.ids = acpi_apd_device_ids,
+	.attach = acpi_apd_create_device,
+};
+
+void __init acpi_apd_init(void)
+{
+	acpi_scan_add_handler(&apd_handler);
+}

drivers/acpi/internal.h

@@ -68,6 +68,8 @@ static inline void acpi_debugfs_init(void) { return; }
 #endif
 void acpi_lpss_init(void);
 
+void acpi_apd_init(void);
+
 acpi_status acpi_hotplug_schedule(struct acpi_device *adev, u32 src);
 bool acpi_queue_hotplug_work(struct work_struct *work);
 void acpi_device_hotplug(struct acpi_device *adev, u32 src);

drivers/acpi/scan.c

@@ -2544,6 +2544,7 @@ int __init acpi_scan_init(void)
 	acpi_pci_link_init();
 	acpi_processor_init();
 	acpi_lpss_init();
+	acpi_apd_init();
 	acpi_cmos_rtc_init();
 	acpi_container_init();
 	acpi_memory_hotplug_init();