[patch 04/32] greybus: host driver framework

[Greg KH]

This is the Greybus host driver framework files and logic.

Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/greybus/hd.c |  257 +++++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/greybus/hd.h |   90 +++++++++++++++++
 2 files changed, 347 insertions(+)

--- /dev/null
+++ b/drivers/greybus/hd.c
@@ -0,0 +1,257 @@
+/*
+ * Greybus Host Device
+ *
+ * Copyright 2014-2015 Google Inc.
+ * Copyright 2014-2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "greybus.h"
+#include "greybus_trace.h"
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_create);
+EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_release);
+EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_add);
+EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_del);
+EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_in);
+EXPORT_TRACEPOINT_SYMBOL_GPL(gb_message_submit);
+
+static struct ida gb_hd_bus_id_map;
+
+int gb_hd_output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
+		 bool async)
+{
+	if (!hd || !hd->driver || !hd->driver->output)
+		return -EINVAL;
+	return hd->driver->output(hd, req, size, cmd, async);
+}
+EXPORT_SYMBOL_GPL(gb_hd_output);
+
+static ssize_t bus_id_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct gb_host_device *hd = to_gb_host_device(dev);
+
+	return sprintf(buf, "%d\n", hd->bus_id);
+}
+static DEVICE_ATTR_RO(bus_id);
+
+static struct attribute *bus_attrs[] = {
+	&dev_attr_bus_id.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(bus);
+
+int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id)
+{
+	struct ida *id_map = &hd->cport_id_map;
+	int ret;
+
+	ret = ida_simple_get(id_map, cport_id, cport_id + 1, GFP_KERNEL);
+	if (ret < 0) {
+		dev_err(&hd->dev, "failed to reserve cport %u\n", cport_id);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gb_hd_cport_reserve);
+
+void gb_hd_cport_release_reserved(struct gb_host_device *hd, u16 cport_id)
+{
+	struct ida *id_map = &hd->cport_id_map;
+
+	ida_simple_remove(id_map, cport_id);
+}
+EXPORT_SYMBOL_GPL(gb_hd_cport_release_reserved);
+
+/* Locking: Caller guarantees serialisation */
+int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id,
+				unsigned long flags)
+{
+	struct ida *id_map = &hd->cport_id_map;
+	int ida_start, ida_end;
+
+	if (hd->driver->cport_allocate)
+		return hd->driver->cport_allocate(hd, cport_id, flags);
+
+	if (cport_id < 0) {
+		ida_start = 0;
+		ida_end = hd->num_cports;
+	} else if (cport_id < hd->num_cports) {
+		ida_start = cport_id;
+		ida_end = cport_id + 1;
+	} else {
+		dev_err(&hd->dev, "cport %d not available\n", cport_id);
+		return -EINVAL;
+	}
+
+	return ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
+}
+
+/* Locking: Caller guarantees serialisation */
+void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id)
+{
+	if (hd->driver->cport_release) {
+		hd->driver->cport_release(hd, cport_id);
+		return;
+	}
+
+	ida_simple_remove(&hd->cport_id_map, cport_id);
+}
+
+static void gb_hd_release(struct device *dev)
+{
+	struct gb_host_device *hd = to_gb_host_device(dev);
+
+	trace_gb_hd_release(hd);
+
+	if (hd->svc)
+		gb_svc_put(hd->svc);
+	ida_simple_remove(&gb_hd_bus_id_map, hd->bus_id);
+	ida_destroy(&hd->cport_id_map);
+	kfree(hd);
+}
+
+struct device_type greybus_hd_type = {
+	.name		= "greybus_host_device",
+	.release	= gb_hd_release,
+};
+
+struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
+					struct device *parent,
+					size_t buffer_size_max,
+					size_t num_cports)
+{
+	struct gb_host_device *hd;
+	int ret;
+
+	/*
+	 * Validate that the driver implements all of the callbacks
+	 * so that we don't have to every time we make them.
+	 */
+	if ((!driver->message_send) || (!driver->message_cancel)) {
+		dev_err(parent, "mandatory hd-callbacks missing\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (buffer_size_max < GB_OPERATION_MESSAGE_SIZE_MIN) {
+		dev_err(parent, "greybus host-device buffers too small\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (num_cports == 0 || num_cports > CPORT_ID_MAX + 1) {
+		dev_err(parent, "Invalid number of CPorts: %zu\n", num_cports);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/*
+	 * Make sure to never allocate messages larger than what the Greybus
+	 * protocol supports.
+	 */
+	if (buffer_size_max > GB_OPERATION_MESSAGE_SIZE_MAX) {
+		dev_warn(parent, "limiting buffer size to %u\n",
+			 GB_OPERATION_MESSAGE_SIZE_MAX);
+		buffer_size_max = GB_OPERATION_MESSAGE_SIZE_MAX;
+	}
+
+	hd = kzalloc(sizeof(*hd) + driver->hd_priv_size, GFP_KERNEL);
+	if (!hd)
+		return ERR_PTR(-ENOMEM);
+
+	ret = ida_simple_get(&gb_hd_bus_id_map, 1, 0, GFP_KERNEL);
+	if (ret < 0) {
+		kfree(hd);
+		return ERR_PTR(ret);
+	}
+	hd->bus_id = ret;
+
+	hd->driver = driver;
+	INIT_LIST_HEAD(&hd->modules);
+	INIT_LIST_HEAD(&hd->connections);
+	ida_init(&hd->cport_id_map);
+	hd->buffer_size_max = buffer_size_max;
+	hd->num_cports = num_cports;
+
+	hd->dev.parent = parent;
+	hd->dev.bus = &greybus_bus_type;
+	hd->dev.type = &greybus_hd_type;
+	hd->dev.groups = bus_groups;
+	hd->dev.dma_mask = hd->dev.parent->dma_mask;
+	device_initialize(&hd->dev);
+	dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
+
+	trace_gb_hd_create(hd);
+
+	hd->svc = gb_svc_create(hd);
+	if (!hd->svc) {
+		dev_err(&hd->dev, "failed to create svc\n");
+		put_device(&hd->dev);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return hd;
+}
+EXPORT_SYMBOL_GPL(gb_hd_create);
+
+int gb_hd_add(struct gb_host_device *hd)
+{
+	int ret;
+
+	ret = device_add(&hd->dev);
+	if (ret)
+		return ret;
+
+	ret = gb_svc_add(hd->svc);
+	if (ret) {
+		device_del(&hd->dev);
+		return ret;
+	}
+
+	trace_gb_hd_add(hd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gb_hd_add);
+
+void gb_hd_del(struct gb_host_device *hd)
+{
+	trace_gb_hd_del(hd);
+
+	/*
+	 * Tear down the svc and flush any on-going hotplug processing before
+	 * removing the remaining interfaces.
+	 */
+	gb_svc_del(hd->svc);
+
+	device_del(&hd->dev);
+}
+EXPORT_SYMBOL_GPL(gb_hd_del);
+
+void gb_hd_shutdown(struct gb_host_device *hd)
+{
+	gb_svc_del(hd->svc);
+}
+EXPORT_SYMBOL_GPL(gb_hd_shutdown);
+
+void gb_hd_put(struct gb_host_device *hd)
+{
+	put_device(&hd->dev);
+}
+EXPORT_SYMBOL_GPL(gb_hd_put);
+
+int __init gb_hd_init(void)
+{
+	ida_init(&gb_hd_bus_id_map);
+
+	return 0;
+}
+
+void gb_hd_exit(void)
+{
+	ida_destroy(&gb_hd_bus_id_map);
+}
--- /dev/null
+++ b/drivers/greybus/hd.h
@@ -0,0 +1,90 @@
+/*
+ * Greybus Host Device
+ *
+ * Copyright 2014-2015 Google Inc.
+ * Copyright 2014-2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#ifndef __HD_H
+#define __HD_H
+
+struct gb_host_device;
+struct gb_message;
+
+struct gb_hd_driver {
+	size_t	hd_priv_size;
+
+	int (*cport_allocate)(struct gb_host_device *hd, int cport_id,
+				unsigned long flags);
+	void (*cport_release)(struct gb_host_device *hd, u16 cport_id);
+	int (*cport_enable)(struct gb_host_device *hd, u16 cport_id,
+				unsigned long flags);
+	int (*cport_disable)(struct gb_host_device *hd, u16 cport_id);
+	int (*cport_connected)(struct gb_host_device *hd, u16 cport_id);
+	int (*cport_flush)(struct gb_host_device *hd, u16 cport_id);
+	int (*cport_shutdown)(struct gb_host_device *hd, u16 cport_id,
+				u8 phase, unsigned int timeout);
+	int (*cport_quiesce)(struct gb_host_device *hd, u16 cport_id,
+				size_t peer_space, unsigned int timeout);
+	int (*cport_clear)(struct gb_host_device *hd, u16 cport_id);
+
+	int (*message_send)(struct gb_host_device *hd, u16 dest_cport_id,
+			struct gb_message *message, gfp_t gfp_mask);
+	void (*message_cancel)(struct gb_message *message);
+	int (*latency_tag_enable)(struct gb_host_device *hd, u16 cport_id);
+	int (*latency_tag_disable)(struct gb_host_device *hd, u16 cport_id);
+	int (*output)(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
+		      bool async);
+	int (*timesync_enable)(struct gb_host_device *hd, u8 count,
+			       u64 frame_time, u32 strobe_delay, u32 refclk);
+	int (*timesync_disable)(struct gb_host_device *hd);
+	int (*timesync_authoritative)(struct gb_host_device *hd,
+				      u64 *frame_time);
+	int (*timesync_get_last_event)(struct gb_host_device *hd,
+				       u64 *frame_time);
+};
+
+struct gb_host_device {
+	struct device dev;
+	int bus_id;
+	const struct gb_hd_driver *driver;
+
+	struct list_head modules;
+	struct list_head connections;
+	struct ida cport_id_map;
+
+	/* Number of CPorts supported by the UniPro IP */
+	size_t num_cports;
+
+	/* Host device buffer constraints */
+	size_t buffer_size_max;
+
+	struct gb_svc *svc;
+	/* Private data for the host driver */
+	unsigned long hd_priv[0] __aligned(sizeof(s64));
+};
+#define to_gb_host_device(d) container_of(d, struct gb_host_device, dev)
+
+int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id);
+void gb_hd_cport_release_reserved(struct gb_host_device *hd, u16 cport_id);
+int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id,
+					unsigned long flags);
+void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id);
+
+struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
+					struct device *parent,
+					size_t buffer_size_max,
+					size_t num_cports);
+int gb_hd_add(struct gb_host_device *hd);
+void gb_hd_del(struct gb_host_device *hd);
+void gb_hd_shutdown(struct gb_host_device *hd);
+void gb_hd_put(struct gb_host_device *hd);
+int gb_hd_output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
+		 bool in_irq);
+
+int gb_hd_init(void);
+void gb_hd_exit(void);
+
+#endif	/* __HD_H */