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|
/*
* Greybus "AP" USB driver
*
* Copyright 2014 Google Inc.
*
* Released under the GPLv2 only.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/sizes.h>
#include <linux/usb.h>
#include "greybus.h"
#include "svc_msg.h"
#include "kernel_ver.h"
/* Memory sizes for the buffers sent to/from the ES1 controller */
#define ES1_SVC_MSG_SIZE (sizeof(struct svc_msg) + SZ_64K)
#define ES1_GBUF_MSG_SIZE PAGE_SIZE
static const struct usb_device_id id_table[] = {
/* Made up numbers for the SVC USB Bridge in ES1 */
{ USB_DEVICE(0xffff, 0x0001) },
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
/*
* Number of CPort IN urbs in flight at any point in time.
* Adjust if we are having stalls in the USB buffer due to not enough urbs in
* flight.
*/
#define NUM_CPORT_IN_URB 4
/* Number of CPort OUT urbs in flight at any point in time.
* Adjust if we get messages saying we are out of urbs in the system log.
*/
#define NUM_CPORT_OUT_URB 8
/**
* es1_ap_dev - ES1 USB Bridge to AP structure
* @usb_dev: pointer to the USB device we are.
* @usb_intf: pointer to the USB interface we are bound to.
* @hd: pointer to our greybus_host_device structure
* @control_endpoint: endpoint to send data to SVC
* @svc_endpoint: endpoint for SVC data in
* @cport_in_endpoint: bulk in endpoint for CPort data
* @cport-out_endpoint: bulk out endpoint for CPort data
* @svc_buffer: buffer for SVC messages coming in on @svc_endpoint
* @svc_urb: urb for SVC messages coming in on @svc_endpoint
* @cport_in_urb: array of urbs for the CPort in messages
* @cport_in_buffer: array of buffers for the @cport_in_urb urbs
* @cport_out_urb: array of urbs for the CPort out messages
* @cport_out_urb_busy: array of flags to see if the @cport_out_urb is busy or
* not.
* @cport_out_urb_lock: locks the @cport_out_urb_busy "list"
*/
struct es1_ap_dev {
struct usb_device *usb_dev;
struct usb_interface *usb_intf;
struct greybus_host_device *hd;
__u8 control_endpoint;
__u8 svc_endpoint;
__u8 cport_in_endpoint;
__u8 cport_out_endpoint;
u8 *svc_buffer;
struct urb *svc_urb;
struct urb *cport_in_urb[NUM_CPORT_IN_URB];
u8 *cport_in_buffer[NUM_CPORT_IN_URB];
struct urb *cport_out_urb[NUM_CPORT_OUT_URB];
bool cport_out_urb_busy[NUM_CPORT_OUT_URB];
spinlock_t cport_out_urb_lock;
};
static inline struct es1_ap_dev *hd_to_es1(struct greybus_host_device *hd)
{
return (struct es1_ap_dev *)&hd->hd_priv;
}
static void cport_out_callback(struct urb *urb);
/*
* 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 int alloc_gbuf_data(struct gbuf *gbuf, unsigned int size, gfp_t gfp_mask)
{
struct es1_ap_dev *es1 = hd_to_es1(gbuf->gmod->hd);
u8 *buffer;
if (size > ES1_GBUF_MSG_SIZE) {
pr_err("guf was asked to be bigger than %ld!\n",
ES1_GBUF_MSG_SIZE);
}
/* 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"
*/
BUG_ON(gbuf->cport_id > (u16)U8_MAX);
buffer[0] = gbuf->cport_id;
gbuf->transfer_buffer = &buffer[1];
gbuf->transfer_buffer_length = size;
gbuf->actual_length = size;
/* When we send the gbuf, we need this pointer to be here */
gbuf->hdpriv = es1;
return 0;
}
/* Free the memory we allocated with a gbuf */
static void free_gbuf_data(struct gbuf *gbuf)
{
u8 *transfer_buffer;
u8 *buffer;
transfer_buffer = gbuf->transfer_buffer;
/* Can be called with a NULL transfer_buffer on some error paths */
if (transfer_buffer) {
buffer = &transfer_buffer[-1]; /* yes, we mean -1 */
kfree(buffer);
}
}
#define ES1_TIMEOUT 500 /* 500 ms for the SVC to do something */
static int submit_svc(struct svc_msg *svc_msg, struct greybus_host_device *hd)
{
struct es1_ap_dev *es1 = hd_to_es1(hd);
int retval;
/* SVC messages go down our control pipe */
retval = usb_control_msg(es1->usb_dev,
usb_sndctrlpipe(es1->usb_dev,
es1->control_endpoint),
0x01, /* vendor request AP message */
USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
0x00, 0x00,
(char *)svc_msg,
sizeof(*svc_msg),
ES1_TIMEOUT);
if (retval != sizeof(*svc_msg))
return retval;
return 0;
}
static struct urb *next_free_urb(struct es1_ap_dev *es1, gfp_t gfp_mask)
{
struct urb *urb = NULL;
unsigned long flags;
int i;
spin_lock_irqsave(&es1->cport_out_urb_lock, flags);
/* Look in our pool of allocated urbs first, as that's the "fastest" */
for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
if (es1->cport_out_urb_busy[i] == false) {
es1->cport_out_urb_busy[i] = true;
urb = es1->cport_out_urb[i];
break;
}
}
spin_unlock_irqrestore(&es1->cport_out_urb_lock, flags);
if (urb)
return urb;
/*
* Crap, pool is empty, complain to the syslog and go allocate one
* dynamically as we have to succeed.
*/
dev_err(&es1->usb_dev->dev,
"No free CPort OUT urbs, having to dynamically allocate one!\n");
urb = usb_alloc_urb(0, gfp_mask);
if (!urb)
return NULL;
return urb;
}
static int submit_gbuf(struct gbuf *gbuf, struct greybus_host_device *hd,
gfp_t gfp_mask)
{
struct es1_ap_dev *es1 = hd_to_es1(hd);
struct usb_device *udev = es1->usb_dev;
int retval;
u8 *transfer_buffer;
u8 *buffer;
struct urb *urb;
transfer_buffer = gbuf->transfer_buffer;
buffer = &transfer_buffer[-1]; /* yes, we mean -1 */
/* Find a free urb */
urb = next_free_urb(es1, gfp_mask);
if (!urb)
return -ENOMEM;
usb_fill_bulk_urb(urb, udev,
usb_sndbulkpipe(udev, es1->cport_out_endpoint),
buffer, gbuf->transfer_buffer_length + 1,
cport_out_callback, gbuf);
retval = usb_submit_urb(urb, gfp_mask);
return retval;
}
static struct greybus_host_driver es1_driver = {
.hd_priv_size = sizeof(struct es1_ap_dev),
.alloc_gbuf_data = alloc_gbuf_data,
.free_gbuf_data = free_gbuf_data,
.submit_svc = submit_svc,
.submit_gbuf = submit_gbuf,
};
/* Common function to report consistent warnings based on URB status */
static int check_urb_status(struct urb *urb)
{
struct device *dev = &urb->dev->dev;
int status = urb->status;
switch (status) {
case 0:
return 0;
case -EOVERFLOW:
dev_err(dev, "%s: overflow actual length is %d\n",
__func__, urb->actual_length);
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
case -EILSEQ:
/* device is gone, stop sending */
return status;
}
dev_err(dev, "%s: unknown status %d\n", __func__, status);
return -EAGAIN;
}
/* Callback for when we get a SVC message */
static void svc_in_callback(struct urb *urb)
{
struct es1_ap_dev *es1 = urb->context;
struct device *dev = &urb->dev->dev;
int status = check_urb_status(urb);
int retval;
if (status == -EAGAIN)
goto exit;
if (status)
return;
/* We have a message, create a new message structure, add it to the
* list, and wake up our thread that will process the messages.
*/
greybus_svc_in(es1->hd, urb->transfer_buffer, urb->actual_length);
exit:
/* resubmit the urb to get more messages */
retval = usb_submit_urb(urb, GFP_ATOMIC);
if (retval)
dev_err(dev, "Can not submit urb for AP data: %d\n", retval);
}
static void cport_in_callback(struct urb *urb)
{
struct device *dev = &urb->dev->dev;
struct es1_ap_dev *es1 = urb->context;
int status = check_urb_status(urb);
int retval;
u8 cport;
u8 *data;
if (status == -EAGAIN)
goto exit;
if (status)
return;
/* The size has to be more then just an "empty" transfer */
if (urb->actual_length <= 2) {
dev_err(dev, "%s: \"short\" cport in transfer of %d bytes?\n",
__func__, urb->actual_length);
goto exit;
}
/*
* The CPort number is the first byte of the data stream, the rest of
* the stream is "real" data
*/
data = urb->transfer_buffer;
cport = data[0];
data = &data[1];
/* Pass this data to the greybus core */
greybus_cport_in(es1->hd, cport, data, urb->actual_length - 1);
exit:
/* put our urb back in the request pool */
retval = usb_submit_urb(urb, GFP_ATOMIC);
if (retval)
dev_err(dev, "%s: error %d in submitting urb.\n",
__func__, retval);
}
static void cport_out_callback(struct urb *urb)
{
struct gbuf *gbuf = urb->context;
struct es1_ap_dev *es1 = gbuf->hdpriv;
unsigned long flags;
int i;
/* If no error, tell the core the gbuf is properly sent */
if (!check_urb_status(urb))
greybus_gbuf_finished(gbuf);
/*
* See if this was an urb in our pool, if so mark it "free", otherwise
* we need to free it ourselves.
*/
spin_lock_irqsave(&es1->cport_out_urb_lock, flags);
for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
if (urb == es1->cport_out_urb[i]) {
es1->cport_out_urb_busy[i] = false;
urb = NULL;
break;
}
}
spin_unlock_irqrestore(&es1->cport_out_urb_lock, flags);
/* If urb is not NULL, then we need to free this urb */
usb_free_urb(urb);
}
/*
* The ES1 USB Bridge device contains 4 endpoints
* 1 Control - usual USB stuff + AP -> SVC messages
* 1 Interrupt IN - SVC -> AP messages
* 1 Bulk IN - CPort data in
* 1 Bulk OUT - CPort data out
*/
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;
bool int_in_found = false;
bool bulk_in_found = false;
bool bulk_out_found = false;
int retval = -ENOMEM;
int i;
u8 svc_interval = 0;
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;
es1->usb_intf = interface;
es1->usb_dev = udev;
spin_lock_init(&es1->cport_out_urb_lock);
usb_set_intfdata(interface, es1);
/* Control endpoint is the pipe to talk to this AP, so save it off */
endpoint = &udev->ep0.desc;
es1->control_endpoint = endpoint->bEndpointAddress;
/* find all 3 of our endpoints */
iface_desc = interface->cur_altsetting;
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
endpoint = &iface_desc->endpoint[i].desc;
if (usb_endpoint_is_int_in(endpoint)) {
es1->svc_endpoint = endpoint->bEndpointAddress;
svc_interval = endpoint->bInterval;
int_in_found = true;
} else if (usb_endpoint_is_bulk_in(endpoint)) {
es1->cport_in_endpoint = endpoint->bEndpointAddress;
bulk_in_found = true;
} else if (usb_endpoint_is_bulk_out(endpoint)) {
es1->cport_out_endpoint = endpoint->bEndpointAddress;
bulk_out_found = true;
} else {
dev_err(&udev->dev,
"Unknown endpoint type found, address %x\n",
endpoint->bEndpointAddress);
}
}
if ((int_in_found == false) ||
(bulk_in_found == false) ||
(bulk_out_found == false)) {
dev_err(&udev->dev, "Not enough endpoints found in device, aborting!\n");
goto error;
}
/* Create our buffer and URB to get SVC messages, and start it up */
es1->svc_buffer = kmalloc(ES1_SVC_MSG_SIZE, GFP_KERNEL);
if (!es1->svc_buffer)
goto error;
es1->svc_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!es1->svc_urb)
goto error_int_urb;
usb_fill_int_urb(es1->svc_urb, udev,
usb_rcvintpipe(udev, es1->svc_endpoint),
es1->svc_buffer, ES1_SVC_MSG_SIZE, svc_in_callback,
es1, svc_interval);
retval = usb_submit_urb(es1->svc_urb, GFP_KERNEL);
if (retval)
goto error_submit_urb;
/* Allocate buffers for our cport in messages and start them up */
for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
struct urb *urb;
u8 *buffer;
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb)
goto error_bulk_in_urb;
buffer = kmalloc(ES1_GBUF_MSG_SIZE, GFP_KERNEL);
if (!buffer)
goto error_bulk_in_urb;
usb_fill_bulk_urb(urb, udev,
usb_rcvbulkpipe(udev, es1->cport_in_endpoint),
buffer, PAGE_SIZE, cport_in_callback, es1);
es1->cport_in_urb[i] = urb;
es1->cport_in_buffer[i] = buffer;
retval = usb_submit_urb(urb, GFP_KERNEL);
if (retval)
goto error_bulk_in_urb;
}
/* Allocate urbs for our CPort OUT messages */
for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
struct urb *urb;
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb)
goto error_bulk_out_urb;
es1->cport_out_urb[i] = urb;
es1->cport_out_urb_busy[i] = false; /* just to be anal */
}
return 0;
error_bulk_out_urb:
for (i = 0; i < NUM_CPORT_OUT_URB; ++i)
usb_free_urb(es1->cport_out_urb[i]);
error_bulk_in_urb:
for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
usb_kill_urb(es1->cport_in_urb[i]);
usb_free_urb(es1->cport_in_urb[i]);
kfree(es1->cport_in_buffer[i]);
}
error_submit_urb:
usb_free_urb(es1->svc_urb);
error_int_urb:
kfree(es1->svc_buffer);
error:
greybus_remove_hd(es1->hd);
return retval;
}
static void ap_disconnect(struct usb_interface *interface)
{
struct es1_ap_dev *es1;
int i;
es1 = usb_get_intfdata(interface);
if (!es1)
return;
/* Tear down everything! */
for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
usb_kill_urb(es1->cport_out_urb[i]);
usb_free_urb(es1->cport_out_urb[i]);
}
for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
usb_kill_urb(es1->cport_in_urb[i]);
usb_free_urb(es1->cport_in_urb[i]);
kfree(es1->cport_in_buffer[i]);
}
usb_kill_urb(es1->svc_urb);
usb_free_urb(es1->svc_urb);
usb_put_dev(es1->usb_dev);
kfree(es1->svc_buffer);
greybus_remove_hd(es1->hd);
usb_set_intfdata(interface, NULL);
}
static struct usb_driver es1_ap_driver = {
.name = "es1_ap_driver",
.probe = ap_probe,
.disconnect = ap_disconnect,
.id_table = id_table,
};
module_usb_driver(es1_ap_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
|