[PATCH v3 12/36] platform/x86: intel_scu_ipc: Split out SCU IPC functionality from the SCU driver

[Mika Westerberg <mika.westerberg@linux.intel.com>]

The SCU IPC functionality is usable outside of Intel MID devices. For
example modern Intel CPUs include the same thing but now it is called
PMC (Power Management Controller) instead of SCU. To make the IPC
available for those split the driver into library part (intel_scu_ipc.c)
and the SCU PCI driver part (intel_scu_pcidrv.c) which then calls the
former before it goes and creates rest of the SCU devices.

We also split the Kconfig symbols so that INTEL_SCU_IPC enables the SCU
IPC library and INTEL_SCU_PCI the SCU driver and convert the users
accordingly. While there remove default y from the INTEL_SCU_PCI symbol
as it is already selected by X86_INTEL_MID.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 arch/x86/Kconfig                        |  2 +-
 arch/x86/include/asm/intel_scu_ipc.h    | 14 +++++
 drivers/mfd/Kconfig                     |  4 +-
 drivers/platform/x86/Kconfig            | 26 ++++++---
 drivers/platform/x86/Makefile           |  1 +
 drivers/platform/x86/intel_scu_ipc.c    | 75 +++++++++----------------
 drivers/platform/x86/intel_scu_pcidrv.c | 61 ++++++++++++++++++++
 7 files changed, 122 insertions(+), 61 deletions(-)
 create mode 100644 drivers/platform/x86/intel_scu_pcidrv.c

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5e8949953660..aca17d1583c4 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -594,7 +594,7 @@ config X86_INTEL_MID
 	select I2C
 	select DW_APB_TIMER
 	select APB_TIMER
-	select INTEL_SCU_IPC
+	select INTEL_SCU_PCI
 	select MFD_INTEL_MSIC
 	---help---
 	  Select to build a kernel capable of supporting Intel MID (Mobile
diff --git a/arch/x86/include/asm/intel_scu_ipc.h b/arch/x86/include/asm/intel_scu_ipc.h
index 2a1442ba6e78..d6feb96d98e3 100644
--- a/arch/x86/include/asm/intel_scu_ipc.h
+++ b/arch/x86/include/asm/intel_scu_ipc.h
@@ -19,6 +19,20 @@
 	#define IPC_CMD_VRTC_SETTIME      1 /* Set time */
 	#define IPC_CMD_VRTC_SETALARM     2 /* Set alarm */
 
+struct device;
+
+/**
+ * struct intel_scu_ipc_pdata - Platform data for SCU IPC
+ * @ipc_regs: IPC regs MMIO address
+ * @irq: The IRQ number used for SCU (optional)
+ */
+struct intel_scu_ipc_pdata {
+	void __iomem *ipc_regs;
+	int irq;
+};
+
+int intel_scu_ipc_probe(struct device *dev, const struct intel_scu_ipc_pdata *pdata);
+
 /* Read single register */
 int intel_scu_ipc_ioread8(u16 addr, u8 *data);
 
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 420900852166..59515142438e 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -593,7 +593,7 @@ config INTEL_SOC_PMIC_MRFLD
 	tristate "Support for Intel Merrifield Basin Cove PMIC"
 	depends on GPIOLIB
 	depends on ACPI
-	depends on INTEL_SCU_IPC
+	depends on INTEL_SCU
 	select MFD_CORE
 	select REGMAP_IRQ
 	help
@@ -625,7 +625,7 @@ config MFD_INTEL_LPSS_PCI
 
 config MFD_INTEL_MSIC
 	bool "Intel MSIC"
-	depends on INTEL_SCU_IPC
+	depends on INTEL_SCU
 	select MFD_CORE
 	help
 	  Select this option to enable access to Intel MSIC (Avatele
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index dd4326736d11..50deff627b46 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -986,25 +986,33 @@ config INTEL_VBTN
 	  be called intel_vbtn.
 
 config INTEL_SCU_IPC
-	bool "Intel SCU IPC Support"
+	bool
+
+config INTEL_SCU
+	bool
+	select INTEL_SCU_IPC
+
+config INTEL_SCU_PCI
+	bool "Intel SCU PCI driver"
 	depends on X86_INTEL_MID
-	default y
-	---help---
-	  IPC is used to bridge the communications between kernel and SCU on
-	  some embedded Intel x86 platforms. This is not needed for PC-type
-	  machines.
+	select INTEL_SCU
+	help
+	  This driver is used to bridge the communications between kernel
+	  and SCU on some embedded Intel x86 platforms. It also creates
+	  devices that are connected to the SoC through the SCU. This is
+	  not needed for PC-type machines.
 
 config INTEL_SCU_IPC_UTIL
 	tristate "Intel SCU IPC utility driver"
-	depends on INTEL_SCU_IPC
-	---help---
+	depends on INTEL_SCU
+	help
 	  The IPC Util driver provides an interface with the SCU enabling
 	  low level access for debug work and updating the firmware. Say
 	  N unless you will be doing this on an Intel MID platform.
 
 config INTEL_MID_POWER_BUTTON
 	tristate "power button driver for Intel MID platforms"
-	depends on INTEL_SCU_IPC && INPUT
+	depends on INTEL_SCU && INPUT
 	help
 	  This driver handles the power button on the Intel MID platforms.
 
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 42d85a00be4e..c7a42feaa521 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -68,6 +68,7 @@ intel_cht_int33fe-objs		:= intel_cht_int33fe_common.o \
 obj-$(CONFIG_INTEL_INT0002_VGPIO) += intel_int0002_vgpio.o
 obj-$(CONFIG_INTEL_HID_EVENT)	+= intel-hid.o
 obj-$(CONFIG_INTEL_VBTN)	+= intel-vbtn.o
+obj-$(CONFIG_INTEL_SCU_PCI)	+= intel_scu_pcidrv.o
 obj-$(CONFIG_INTEL_SCU_IPC)	+= intel_scu_ipc.o
 obj-$(CONFIG_INTEL_SCU_IPC_UTIL) += intel_scu_ipcutil.o
 obj-$(CONFIG_INTEL_MFLD_THERMAL) += intel_mid_thermal.o
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 93a810fa6c8a..acd70b4f687f 100644
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -18,11 +18,8 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
-#include <linux/pci.h>
-#include <linux/pm.h>
-#include <linux/sfi.h>
+#include <linux/io.h>
 
-#include <asm/intel-mid.h>
 #include <asm/intel_scu_ipc.h>
 
 /* IPC defines the following message types */
@@ -58,7 +55,7 @@ struct intel_scu_ipc_dev {
 	struct device *dev;
 	void __iomem *ipc_base;
 	struct completion cmd_complete;
-	u8 irq_mode;
+	int irq;
 };
 
 static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
@@ -166,7 +163,7 @@ static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)
 
 static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)
 {
-	return scu->irq_mode ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
+	return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
 }
 
 /* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
@@ -402,60 +399,40 @@ static irqreturn_t ioc(int irq, void *dev_id)
 }
 
 /**
- *	ipc_probe	-	probe an Intel SCU IPC
- *	@pdev: the PCI device matching
- *	@id: entry in the match table
+ * intel_scu_ipc_probe() - Initializes SCU IPC mechanism
+ * @dev: SCU device
+ * @pdata: Platform specific data
  *
- *	Enable and install an intel SCU IPC. This appears in the PCI space
- *	but uses some hard coded addresses as well.
+ * Call this function to initialize SCU IPC mechanism. It is removed
+ * automatically when the calling driver is unbound from @dev.
  */
-static int ipc_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+int intel_scu_ipc_probe(struct device *dev, const struct intel_scu_ipc_pdata *pdata)
 {
 	int err;
 	struct intel_scu_ipc_dev *scu = &ipcdev;
 
-	if (scu->dev)		/* We support only one SCU */
+	mutex_lock(&ipclock);
+	/* We support only one IPC */
+	if (scu->dev) {
+		mutex_unlock(&ipclock);
 		return -EBUSY;
+	}
 
-	err = pcim_enable_device(pdev);
-	if (err)
-		return err;
-
-	err = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
-	if (err)
-		return err;
-
+	scu->ipc_base = pdata->ipc_regs;
+	scu->irq = pdata->irq;
 	init_completion(&scu->cmd_complete);
 
-	scu->ipc_base = pcim_iomap_table(pdev)[0];
-
-	err = devm_request_irq(&pdev->dev, pdev->irq, ioc, 0, "intel_scu_ipc",
-			       scu);
-	if (err)
-		return err;
+	if (scu->irq > 0) {
+		err = devm_request_irq(dev, scu->irq, ioc, 0, "intel_scu_ipc", scu);
+		if (err)
+			goto unlock;
+	}
 
 	/* Assign device at last */
-	scu->dev = &pdev->dev;
-
-	intel_scu_devices_create();
+	scu->dev = dev;
 
-	pci_set_drvdata(pdev, scu);
-	return 0;
+unlock:
+	mutex_unlock(&ipclock);
+	return err;
 }
-
-static const struct pci_device_id pci_ids[] = {
-	{ PCI_VDEVICE(INTEL, 0x080e) },
-	{ PCI_VDEVICE(INTEL, 0x08ea) },
-	{ PCI_VDEVICE(INTEL, 0x11a0) },
-	{ }
-};
-
-static struct pci_driver ipc_driver = {
-	.driver = {
-		.suppress_bind_attrs = true,
-	},
-	.name = "intel_scu_ipc",
-	.id_table = pci_ids,
-	.probe = ipc_probe,
-};
-builtin_pci_driver(ipc_driver);
+EXPORT_SYMBOL_GPL(intel_scu_ipc_probe);
diff --git a/drivers/platform/x86/intel_scu_pcidrv.c b/drivers/platform/x86/intel_scu_pcidrv.c
new file mode 100644
index 000000000000..47dd4d85bf2a
--- /dev/null
+++ b/drivers/platform/x86/intel_scu_pcidrv.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI driver for the Intel SCU.
+ *
+ * Copyright (C) 2008-2010, 2015, 2020 Intel Corporation
+ * Authors: Sreedhara DS (sreedhara.ds@intel.com)
+ *	    Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+
+#include <asm/intel-mid.h>
+#include <asm/intel_scu_ipc.h>
+
+static int intel_scu_pci_probe(struct pci_dev *pdev,
+			       const struct pci_device_id *id)
+{
+	struct intel_scu_ipc_pdata *pdata;
+	int ret;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
+	if (ret)
+		return ret;
+
+	pdata->ipc_regs = pcim_iomap_table(pdev)[0];
+	pdata->irq = pdev->irq;
+
+	ret = intel_scu_ipc_probe(&pdev->dev, pdata);
+	if (ret)
+		return ret;
+
+	intel_scu_devices_create();
+	return 0;
+}
+
+static const struct pci_device_id pci_ids[] = {
+	{ PCI_VDEVICE(INTEL, 0x080e) },
+	{ PCI_VDEVICE(INTEL, 0x08ea) },
+	{ PCI_VDEVICE(INTEL, 0x11a0) },
+	{}
+};
+
+static struct pci_driver intel_scu_pci_driver = {
+	.driver = {
+		.suppress_bind_attrs = true,
+	},
+	.name = "intel_scu",
+	.id_table = pci_ids,
+	.probe = intel_scu_pci_probe,
+};
+builtin_pci_driver(intel_scu_pci_driver);
-- 
2.24.1