greybus: host controller additions

Also some gbuf functions starting to get fleshed out.

drivers/staging/greybus/core.c

@@ -449,6 +449,22 @@ void greybus_remove_device(struct greybus_device *gdev)
 	// FIXME - device_remove(&gdev->dev);
 }
 
+struct greybus_host_device *greybus_create_hd(struct greybus_host_driver *driver,
+					      struct device *parent)
+{
+	struct greybus_host_device *hd;
+
+	hd = kzalloc(sizeof(*hd) + driver->hd_priv_size, GFP_KERNEL);
+	if (!hd)
+		return NULL;
+
+	kref_init(&hd->kref);
+
+	return hd;
+}
+EXPORT_SYMBOL_GPL(greybus_create_hd);
+
+
 static int __init gb_init(void)
 {
 	int retval;

drivers/staging/greybus/es1-ap-usb.c

@@ -13,7 +13,7 @@
 #include "greybus.h"
 
 static const struct usb_device_id id_table[] = {
-	{ USB_DEVICE(0x0000, 0x0000) },		// FIXME
+	{ USB_DEVICE(0xffff, 0x0001) },		// FIXME
 	{ },
 };
 MODULE_DEVICE_TABLE(usb, id_table);
@@ -21,18 +21,73 @@ MODULE_DEVICE_TABLE(usb, id_table);
 struct es1_ap_dev {
 	struct usb_device *usb_dev;
 	struct usb_interface *usb_intf;
+	struct greybus_host_device *hd;
 
-	__u8 ap_in_endpoint;
-	__u8 ap_out_endpoint;
+	__u8 ap_comm_endpoint;		/* endpoint to talk to the AP */
+	__u8 ap_in_endpoint;		/* bulk in for CPort data */
+	__u8 ap_out_endpoint;		/* bulk out for CPort data */
 	u8 *ap_buffer;
 
 };
 
+static inline struct es1_ap_dev *hd_to_es1(struct greybus_host_device *hd)
+{
+	return (struct es1_ap_dev *)(hd->hd_priv);
+}
+
 /*
- * Hack, we "know" we will only have one of these at any one time, so only
- * create one static structure pointer.
+ * Allocate the actual buffer for this gbuf and device and cport
+ *
+ * We are responsible for setting the following fields in a struct gbuf:
+ *	void *hcpriv;
+ *	void *transfer_buffer;
+ *	u32 transfer_buffer_length;
  */
-static struct es1_ap_dev *es1_ap_dev;
+static int alloc_gbuf(struct gbuf *gbuf, unsigned int size, gfp_t gfp_mask)
+{
+	struct es1_ap_dev *es1 = hd_to_es1(gbuf->gdev->hd);
+	u8 *buffer;
+
+	/* For ES2 we need to figure out what cport is going to what endpoint,
+	 * but for ES1, it's so dirt simple, we don't have a choice...
+	 *
+	 * Also, do a "slow" allocation now, if we need speed, use a cache
+	 */
+	buffer = kmalloc(size + 1, gfp_mask);
+	if (!buffer)
+		return -ENOMEM;
+
+	/*
+	 * we will encode the cport number in the first byte of the buffer, so
+	 * set the second byte to be the "transfer buffer"
+	 */
+	buffer[0] = gbuf->cport->number;
+	gbuf->transfer_buffer = &buffer[1];
+	gbuf->transfer_buffer_length = size;
+
+	gbuf->hdpriv = es1;	/* really, we could do something else here... */
+
+	return 0;
+}
+
+/* Free the memory we allocated with a gbuf */
+static void free_gbuf(struct gbuf *gbuf)
+{
+	u8 *transfer_buffer;
+	u8 *buffer;
+
+	transfer_buffer = gbuf->transfer_buffer;
+	buffer = &transfer_buffer[-1];	/* yes, we mean -1 */
+	kfree(buffer);
+}
+
+
+static struct greybus_host_driver es1_driver = {
+	.hd_priv_size = sizeof(struct es1_ap_dev),
+	.alloc_gbuf = alloc_gbuf,
+	.free_gbuf = free_gbuf,
+};
+
 
 void ap_in_callback(struct urb *urb)
 {
@@ -100,19 +155,26 @@ void ap_out_callback(struct urb *urb)
 static int ap_probe(struct usb_interface *interface,
 		    const struct usb_device_id *id)
 {
+	struct es1_ap_dev *es1;
+	struct greybus_host_device *hd;
+	struct usb_device *udev;
 	struct usb_host_interface *iface_desc;
 	struct usb_endpoint_descriptor *endpoint;
-	size_t buffer_size;
 	int i;
 
-	if (es1_ap_dev) {
-		dev_err(&interface->dev, "Already have a es1_ap_dev???\n");
-		return -ENODEV;
-	}
-	es1_ap_dev = kzalloc(sizeof(*es1_ap_dev), GFP_KERNEL);
-	if (!es1_ap_dev)
+	udev = usb_get_dev(interface_to_usbdev(interface));
+
+	hd = greybus_create_hd(&es1_driver, &udev->dev);
+	if (!hd)
 		return -ENOMEM;
 
+	es1 = hd_to_es1(hd);
+	es1->hd = hd;
+
+	/* Control endpoint is the pipe to talk to this AP, so save it off */
+	endpoint = &udev->ep0.desc;
+	es1->ap_comm_endpoint = endpoint->bEndpointAddress;
+
 	// FIXME
 	// figure out endpoint for talking to the AP.
 	iface_desc = interface->cur_altsetting;
@@ -120,13 +182,10 @@ static int ap_probe(struct usb_interface *interface,
 		endpoint = &iface_desc->endpoint[i].desc;
 
 		if (usb_endpoint_is_bulk_in(endpoint)) {
-			buffer_size = usb_endpoint_maxp(endpoint);
-			// FIXME - Save buffer_size?
-			es1_ap_dev->ap_in_endpoint = endpoint->bEndpointAddress;
+			es1->ap_in_endpoint = endpoint->bEndpointAddress;
 		}
 		if (usb_endpoint_is_bulk_out(endpoint)) {
-			// FIXME - anything else about this we need?
-			es1_ap_dev->ap_out_endpoint = endpoint->bEndpointAddress;
+			es1->ap_out_endpoint = endpoint->bEndpointAddress;
 		}
 		// FIXME - properly exit once found the AP endpoint
 		// FIXME - set up cport endpoints
@@ -135,23 +194,25 @@ static int ap_probe(struct usb_interface *interface,
 	// FIXME - allocate buffer
 	// FIXME = start up talking, then create the gb "devices" based on what the AP tells us.
 
-	es1_ap_dev->usb_intf = interface;
-	es1_ap_dev->usb_dev = usb_get_dev(interface_to_usbdev(interface));
-	usb_set_intfdata(interface, es1_ap_dev);
+	es1->usb_intf = interface;
+	es1->usb_dev = udev;
+	usb_set_intfdata(interface, es1);
 	return 0;
 }
 
 static void ap_disconnect(struct usb_interface *interface)
 {
-	es1_ap_dev = usb_get_intfdata(interface);
+	struct es1_ap_dev *es1;
+
+	es1 = usb_get_intfdata(interface);
 
 	/* Tear down everything! */
 
-	usb_put_dev(es1_ap_dev->usb_dev);
-	kfree(es1_ap_dev->ap_buffer);
-	kfree(es1_ap_dev);
-	es1_ap_dev = NULL;
+	usb_put_dev(es1->usb_dev);
+	kfree(es1->ap_buffer);
 
+	// FIXME
+	//greybus_destroy_hd(es1->hd);
 }
 
 static struct usb_driver es1_ap_driver = {

drivers/staging/greybus/gbuf.c

@@ -12,21 +12,93 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/kernel.h>
+#include <linux/kref.h>
 #include <linux/device.h>
+#include <linux/slab.h>
 
 #include "greybus.h"
 
 
+/**
+ * greybus_alloc_gbuf - allocate a greybus buffer
+ *
+ * @gdev: greybus device that wants to allocate this
+ * @cport: cport to send the data to
+ * @complete: callback when the gbuf is finished with
+ * @size: size of the buffer
+ * @gfp_mask: allocation mask
+ * @context: context added to the gbuf by the driver
+ *
+ * TODO: someday it will be nice to handle DMA, but for now, due to the
+ * architecture we are stuck with, the greybus core has to allocate the buffer
+ * that the driver can then fill up with the data to be sent out.  Curse
+ * hardware designers for this issue...
+ */
 struct gbuf *greybus_alloc_gbuf(struct greybus_device *gdev,
 				struct gdev_cport *cport,
-				gfp_t mem_flags)
+				gbuf_complete_t complete,
+				unsigned int size,
+				gfp_t gfp_mask,
+				void *context)
 {
-	return NULL;
+	struct gbuf *gbuf;
+	int retval;
+
+	/*
+	 * change this to a slab allocation if it's too slow, but for now, let's
+	 * be dumb and simple.
+	 */
+	gbuf = kzalloc(sizeof(*gbuf), gfp_mask);
+	if (!gbuf)
+		return NULL;
+
+	kref_init(&gbuf->kref);
+	gbuf->gdev = gdev;
+	gbuf->cport = cport;
+	gbuf->complete = complete;
+	gbuf->context = context;
+
+	/* Host controller specific allocation for the actual buffer */
+	retval = gbuf->gdev->hd->driver->alloc_gbuf(gbuf, size, gfp_mask);
+	if (retval) {
+		kfree(gbuf);
+		return NULL;
+	}
+
+	return gbuf;
+}
+EXPORT_SYMBOL_GPL(greybus_alloc_gbuf);
+
+static DEFINE_MUTEX(gbuf_mutex);
+
+static void free_gbuf(struct kref *kref)
+{
+	struct gbuf *gbuf = container_of(kref, struct gbuf, kref);
+
+	/* let the host controller free what it wants to */
+	gbuf->gdev->hd->driver->free_gbuf(gbuf);
+
+	kfree(gbuf);
 }
 
 void greybus_free_gbuf(struct gbuf *gbuf)
 {
+	/* drop the reference count and get out of here */
+	kref_put_mutex(&gbuf->kref, free_gbuf, &gbuf_mutex);
+
 }
+EXPORT_SYMBOL_GPL(greybus_free_gbuf);
+
+struct gbuf *greybus_get_gbuf(struct gbuf *gbuf)
+{
+	mutex_lock(&gbuf_mutex);
+	kref_get(&gbuf->kref);
+	mutex_unlock(&gbuf_mutex);
+	return gbuf;
+}
+EXPORT_SYMBOL_GPL(greybus_get_gbuf);
+
+
 
 int greybus_submit_gbuf(struct gbuf *gbuf, gfp_t mem_flags)
 {

drivers/staging/greybus/greybus.h

@@ -52,10 +52,7 @@ typedef void (*gbuf_complete_t)(struct gbuf *gbuf);
 
 struct gbuf {
 	struct kref kref;
-	void *hcpriv;
-
-	struct list_head anchor_list;
-	struct gbuf_anchor *anchor;	// FIXME do we need?
+	void *hdpriv;
 
 	struct greybus_device *gdev;
 	struct gdev_cport *cport;
@@ -65,8 +62,10 @@ struct gbuf {
 	u32 transfer_buffer_length;
 	u32 actual_length;
 
+#if 0
 	struct scatterlist *sg;		// FIXME do we need?
 	int num_sgs;
+#endif
 
 	void *context;
 	gbuf_complete_t complete;
@@ -92,6 +91,31 @@ struct gb_gpio_device;
 struct gb_sdio_host;
 struct gb_tty;
 struct gb_usb_device;
+struct greybus_host_device;
+
+/* Greybus "Host driver" structure, needed by a host controller driver to be
+ * able to handle both SVC control as well as "real" greybus messages
+ */
+struct greybus_host_driver {
+	size_t	hd_priv_size;
+
+	int (*start)(struct greybus_host_device *hd);
+	int (*alloc_gbuf)(struct gbuf *gbuf, unsigned int size, gfp_t gfp_mask);
+	void (*free_gbuf)(struct gbuf *gbuf);
+};
+
+struct greybus_host_device {
+	struct kref	kref;
+	const struct greybus_host_driver *driver;
+	unsigned long hd_priv_size;
+
+	/* Private data for the host driver */
+	unsigned long hd_priv[0] __attribute__ ((aligned(sizeof(s64))));
+};
+
+struct greybus_host_device *greybus_create_hd(struct greybus_host_driver *host_driver,
+					      struct device *parent);
+
 
 /* Increase these values if needed */
 #define MAX_CPORTS_PER_MODULE	10
@@ -108,6 +132,8 @@ struct greybus_device {
 	struct gdev_cport *cport[MAX_CPORTS_PER_MODULE];
 	struct gdev_string *string[MAX_STRINGS_PER_MODULE];
 
+	struct greybus_host_device *hd;
+
 	struct gb_i2c_device *gb_i2c_dev;
 	struct gb_gpio_device *gb_gpio_dev;
 	struct gb_sdio_host *gb_sdio_host;
@@ -118,8 +144,13 @@ struct greybus_device {
 
 struct gbuf *greybus_alloc_gbuf(struct greybus_device *gdev,
 				struct gdev_cport *cport,
-				gfp_t mem_flags);
+				gbuf_complete_t complete,
+				unsigned int size,
+				gfp_t gfp_mask,
+				void *context);
 void greybus_free_gbuf(struct gbuf *gbuf);
+struct gbuf *greybus_get_gbuf(struct gbuf *gbuf);
+#define greybus_put_gbuf	greybus_free_gbuf
 
 int greybus_submit_gbuf(struct gbuf *gbuf, gfp_t mem_flags);
 int greybus_kill_gbuf(struct gbuf *gbuf);