fpga: dfl: create a dfl bus type to support DFL devices

A new bus type "dfl" is introduced for private features which are not
initialized by DFL feature drivers (dfl-fme & dfl-afu drivers). So these
private features could be handled by separate driver modules.

DFL feature drivers (dfl-fme, dfl-port) will create DFL devices on
enumeration. DFL drivers could be registered on this bus to match these
DFL devices. They are matched by dfl type & feature_id.

[mdf@kernel.org: Add missing Documentation part to MAINTAINERS file]

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Acked-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

1 files changed, 86 insertions, 0 deletions

diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 5973769430a7..5dc758f655b7 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -236,6 +236,7 @@ struct dfl_feature_irq_ctx {
  * @irq_ctx: interrupt context list.
  * @nr_irqs: number of interrupt contexts.
  * @ops: ops of this sub feature.
+ * @ddev: ptr to the dfl device of this sub feature.
  * @priv: priv data of this feature.
  */
 struct dfl_feature {
@@ -246,6 +247,7 @@ struct dfl_feature {
 	struct dfl_feature_irq_ctx *irq_ctx;
 	unsigned int nr_irqs;
 	const struct dfl_feature_ops *ops;
+	struct dfl_device *ddev;
 	void *priv;
 };
 
@@ -514,4 +516,88 @@ long dfl_feature_ioctl_set_irq(struct platform_device *pdev,
 			       struct dfl_feature *feature,
 			       unsigned long arg);
 
+/**
+ * enum dfl_id_type - define the DFL FIU types
+ */
+enum dfl_id_type {
+	FME_ID,
+	PORT_ID,
+	DFL_ID_MAX,
+};
+
+/**
+ * struct dfl_device_id -  dfl device identifier
+ * @type: contains 4 bits DFL FIU type of the device. See enum dfl_id_type.
+ * @feature_id: contains 12 bits feature identifier local to its DFL FIU type.
+ * @driver_data: driver specific data.
+ */
+struct dfl_device_id {
+	u8 type;
+	u16 feature_id;
+	unsigned long driver_data;
+};
+
+/**
+ * struct dfl_device - represent an dfl device on dfl bus
+ *
+ * @dev: generic device interface.
+ * @id: id of the dfl device.
+ * @type: type of DFL FIU of the device. See enum dfl_id_type.
+ * @feature_id: 16 bits feature identifier local to its DFL FIU type.
+ * @mmio_res: mmio resource of this dfl device.
+ * @irqs: list of Linux IRQ numbers of this dfl device.
+ * @num_irqs: number of IRQs supported by this dfl device.
+ * @cdev: pointer to DFL FPGA container device this dfl device belongs to.
+ * @id_entry: matched id entry in dfl driver's id table.
+ */
+struct dfl_device {
+	struct device dev;
+	int id;
+	u8 type;
+	u16 feature_id;
+	struct resource mmio_res;
+	int *irqs;
+	unsigned int num_irqs;
+	struct dfl_fpga_cdev *cdev;
+	const struct dfl_device_id *id_entry;
+};
+
+/**
+ * struct dfl_driver - represent an dfl device driver
+ *
+ * @drv: driver model structure.
+ * @id_table: pointer to table of device IDs the driver is interested in.
+ *	      { } member terminated.
+ * @probe: mandatory callback for device binding.
+ * @remove: callback for device unbinding.
+ */
+struct dfl_driver {
+	struct device_driver drv;
+	const struct dfl_device_id *id_table;
+
+	int (*probe)(struct dfl_device *dfl_dev);
+	void (*remove)(struct dfl_device *dfl_dev);
+};
+
+#define to_dfl_dev(d) container_of(d, struct dfl_device, dev)
+#define to_dfl_drv(d) container_of(d, struct dfl_driver, drv)
+
+/*
+ * use a macro to avoid include chaining to get THIS_MODULE.
+ */
+#define dfl_driver_register(drv) \
+	__dfl_driver_register(drv, THIS_MODULE)
+int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner);
+void dfl_driver_unregister(struct dfl_driver *dfl_drv);
+
+/*
+ * module_dfl_driver() - Helper macro for drivers that don't do
+ * anything special in module init/exit.  This eliminates a lot of
+ * boilerplate.  Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit().
+ */
+#define module_dfl_driver(__dfl_driver) \
+	module_driver(__dfl_driver, dfl_driver_register, \
+		      dfl_driver_unregister)
+
 #endif /* __FPGA_DFL_H */