[patch 04/32] greybus: host driver framework

From: Greg KH
Date: Fri Sep 16 2016 - 09:23:09 EST



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 */