From f587027e793cf8947c7cc408a2167db2b8218b15 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 21 Jan 2015 10:24:15 +0800 Subject: [PATCH] greybus: es2: add ES2 Greybus Host driver This is just a copy of ES1 for now, things will start to diverge soon. Any common functionality will be factored out over time. Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/Makefile | 1 + drivers/staging/greybus/gb-es2.c | 618 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 619 insertions(+) create mode 100644 drivers/staging/greybus/gb-es2.c diff --git a/drivers/staging/greybus/Makefile b/drivers/staging/greybus/Makefile index 5a7c58d..a5d5470 100644 --- a/drivers/staging/greybus/Makefile +++ b/drivers/staging/greybus/Makefile @@ -22,6 +22,7 @@ obj-m += gb-phy.o obj-m += gb-vibrator.o obj-m += gb-battery.o obj-m += gb-es1.o +obj-m += gb-es2.o KERNELVER ?= $(shell uname -r) KERNELDIR ?= /lib/modules/$(KERNELVER)/build diff --git a/drivers/staging/greybus/gb-es2.c b/drivers/staging/greybus/gb-es2.c new file mode 100644 index 0000000..4154cce --- /dev/null +++ b/drivers/staging/greybus/gb-es2.c @@ -0,0 +1,618 @@ +/* + * Greybus "AP" USB driver for "ES2" controller chips + * + * Copyright 2014 Google Inc. + * Copyright 2014 Linaro Ltd. + * + * Released under the GPLv2 only. + */ +#include +#include +#include +#include +#include +#include + +#include "greybus.h" +#include "svc_msg.h" +#include "kernel_ver.h" + +/* + * Macros for making pointers explicitly opaque, such that the result + * isn't valid but also can't be mistaken for an ERR_PTR() value. + */ +#define conceal_urb(urb) ((void *)((uintptr_t)(urb) ^ 0xbad)) +#define reveal_urb(cookie) ((void *)((uintptr_t)(cookie) ^ 0xbad)) + +/* 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_MAX 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); + +/* + * Buffer constraints for the host driver. + * + * A "buffer" is used to hold data to be transferred for Greybus by + * the host driver. A buffer is represented by a "buffer pointer", + * which defines a region of memory used by the host driver for + * transferring the data. When Greybus allocates a buffer, it must + * do so subject to the constraints associated with the host driver. + * These constraints are specified by two parameters: the + * headroom; and the maximum buffer size. + * + * +------------------+ + * | Host driver | \ + * | reserved area | }- headroom + * | . . . | / + * buffer pointer ---> +------------------+ + * | Buffer space for | \ + * | transferred data | }- buffer size + * | . . . | / (limited to size_max) + * +------------------+ + * + * headroom: Every buffer must have at least this much space + * *before* the buffer pointer, reserved for use by the + * host driver. I.e., ((char *)buffer - headroom) must + * point to valid memory, usable only by the host driver. + * size_max: The maximum size of a buffer (not including the + * headroom) must not exceed this. + */ +static void hd_buffer_constraints(struct greybus_host_device *hd) +{ + /* + * Only one byte is required, but this produces a result + * that's better aligned for the user. + */ + hd->buffer_headroom = sizeof(u32); /* For cport id */ + hd->buffer_size_max = ES1_GBUF_MSG_SIZE_MAX; + BUILD_BUG_ON(hd->buffer_headroom > GB_BUFFER_HEADROOM_MAX); +} + +#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"); + return usb_alloc_urb(0, gfp_mask); +} + +static void free_urb(struct es1_ap_dev *es1, struct urb *urb) +{ + unsigned long flags; + int i; + /* + * 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); +} + +/* + * Returns an opaque cookie value if successful, or a pointer coded + * error otherwise. If the caller wishes to cancel the in-flight + * buffer, it must supply the returned cookie to the cancel routine. + */ +static void *buffer_send(struct greybus_host_device *hd, u16 cport_id, + void *buffer, size_t buffer_size, gfp_t gfp_mask) +{ + struct es1_ap_dev *es1 = hd_to_es1(hd); + struct usb_device *udev = es1->usb_dev; + u8 *transfer_buffer = buffer; + int transfer_buffer_size; + int retval; + struct urb *urb; + + if (!buffer) { + pr_err("null buffer supplied to send\n"); + return ERR_PTR(-EINVAL); + } + if (buffer_size > (size_t)INT_MAX) { + pr_err("bad buffer size (%zu) supplied to send\n", buffer_size); + return ERR_PTR(-EINVAL); + } + transfer_buffer--; + transfer_buffer_size = buffer_size + 1; + + /* + * The data actually transferred will include an indication + * of where the data should be sent. Do one last check of + * the target CPort id before filling it in. + */ + if (cport_id == CPORT_ID_BAD) { + pr_err("request to send inbound data buffer\n"); + return ERR_PTR(-EINVAL); + } + if (cport_id > (u16)U8_MAX) { + pr_err("cport_id (%hd) is out of range for ES1\n", cport_id); + return ERR_PTR(-EINVAL); + } + /* OK, the destination is fine; record it in the transfer buffer */ + *transfer_buffer = cport_id; + + /* Find a free urb */ + urb = next_free_urb(es1, gfp_mask); + if (!urb) + return ERR_PTR(-ENOMEM); + + usb_fill_bulk_urb(urb, udev, + usb_sndbulkpipe(udev, es1->cport_out_endpoint), + transfer_buffer, transfer_buffer_size, + cport_out_callback, hd); + retval = usb_submit_urb(urb, gfp_mask); + if (retval) { + pr_err("error %d submitting URB\n", retval); + free_urb(es1, urb); + return ERR_PTR(retval); + } + + return conceal_urb(urb); +} + +/* + * The cookie value supplied is the value that buffer_send() + * returned to its caller. It identifies the buffer that should be + * canceled. This function must also handle (which is to say, + * ignore) a null cookie value. + */ +static void buffer_cancel(void *cookie) +{ + + /* + * We really should be defensive and track all outstanding + * (sent) buffers rather than trusting the cookie provided + * is valid. For the time being, this will do. + */ + if (cookie) + usb_kill_urb(reveal_urb(cookie)); +} + +static struct greybus_host_driver es1_driver = { + .hd_priv_size = sizeof(struct es1_ap_dev), + .buffer_send = buffer_send, + .buffer_cancel = buffer_cancel, + .submit_svc = submit_svc, +}; + +/* 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: + case -EPROTO: + /* device is gone, stop sending */ + return status; + } + dev_err(dev, "%s: unknown status %d\n", __func__, status); + + return -EAGAIN; +} + +static void ap_disconnect(struct usb_interface *interface) +{ + struct es1_ap_dev *es1; + struct usb_device *udev; + int i; + + es1 = usb_get_intfdata(interface); + if (!es1) + return; + + /* Tear down everything! */ + for (i = 0; i < NUM_CPORT_OUT_URB; ++i) { + struct urb *urb = es1->cport_out_urb[i]; + + if (!urb) + break; + usb_kill_urb(urb); + usb_free_urb(urb); + es1->cport_out_urb[i] = NULL; + es1->cport_out_urb_busy[i] = false; /* just to be anal */ + } + + for (i = 0; i < NUM_CPORT_IN_URB; ++i) { + struct urb *urb = es1->cport_in_urb[i]; + + if (!urb) + break; + usb_kill_urb(urb); + usb_free_urb(urb); + kfree(es1->cport_in_buffer[i]); + es1->cport_in_buffer[i] = NULL; + } + + usb_kill_urb(es1->svc_urb); + usb_free_urb(es1->svc_urb); + es1->svc_urb = NULL; + kfree(es1->svc_buffer); + es1->svc_buffer = NULL; + + usb_set_intfdata(interface, NULL); + udev = es1->usb_dev; + greybus_remove_hd(es1->hd); + + usb_put_dev(udev); +} + +/* Callback for when we get a SVC message */ +static void svc_in_callback(struct urb *urb) +{ + struct greybus_host_device *hd = urb->context; + struct device *dev = &urb->dev->dev; + int status = check_urb_status(urb); + int retval; + + if (status) { + if ((status == -EAGAIN) || (status == -EPROTO)) + goto exit; + dev_err(dev, "urb svc in error %d (dropped)\n", 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(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 greybus_host_device *hd = urb->context; + struct device *dev = &urb->dev->dev; + int status = check_urb_status(urb); + int retval; + u16 cport_id; + u8 *data; + + if (status) { + if ((status == -EAGAIN) || (status == -EPROTO)) + goto exit; + dev_err(dev, "urb cport in error %d (dropped)\n", status); + return; + } + + /* The size has to be at least one, for the cport id */ + if (!urb->actual_length) { + dev_err(dev, "%s: no cport id in input buffer?\n", __func__); + goto exit; + } + + /* + * Our CPort number is the first byte of the data stream, + * the rest of the stream is "real" data + */ + data = urb->transfer_buffer; + cport_id = (u16)data[0]; + data = &data[1]; + + /* Pass this data to the greybus core */ + greybus_data_rcvd(hd, cport_id, 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 greybus_host_device *hd = urb->context; + struct es1_ap_dev *es1 = hd_to_es1(hd); + int status = check_urb_status(urb); + u8 *data = urb->transfer_buffer + 1; + + /* + * Tell the submitter that the buffer send (attempt) is + * complete, and report the status. The submitter's buffer + * starts after the one-byte CPort id we inserted. + */ + data = urb->transfer_buffer + 1; + greybus_data_sent(hd, data, status); + + free_urb(es1, urb); + /* + * Rest assured Greg, this craziness is getting fixed. + * + * Yes, you are right, we aren't telling anyone that the urb finished. + * "That's crazy! How does this all even work?" you might be saying. + * The "magic" is the idea that greybus works on the "operation" level, + * not the "send a buffer" level. All operations are "round-trip" with + * a response from the device that the operation finished, or it will + * time out. Because of that, we don't care that this urb finished, or + * failed, or did anything else, as higher levels of the protocol stack + * will handle completions and timeouts and the rest. + * + * This protocol is "needed" due to some hardware restrictions on the + * current generation of Unipro controllers. Think about it for a + * minute, this is a USB driver, talking to a Unipro bridge, impedance + * mismatch is huge, yet the Unipro controller are even more + * underpowered than this little USB controller. We rely on the round + * trip to keep stalls in the Unipro controllers from happening so that + * we can keep data flowing properly, no matter how slow it might be. + * + * Once again, a wonderful bus protocol cut down in its prime by a naive + * controller chip. We dream of the day we have a "real" HCD for + * Unipro. Until then, we suck it up and make the hardware work, as + * that's the job of the firmware and kernel. + * + */ +} + +/* + * 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) { + usb_put_dev(udev); + return -ENOMEM; + } + + /* Fill in the buffer allocation constraints */ + hd_buffer_constraints(hd); + + 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; + + usb_fill_int_urb(es1->svc_urb, udev, + usb_rcvintpipe(udev, es1->svc_endpoint), + es1->svc_buffer, ES1_SVC_MSG_SIZE, svc_in_callback, + hd, svc_interval); + retval = usb_submit_urb(es1->svc_urb, GFP_KERNEL); + if (retval) + goto error; + + /* 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; + buffer = kmalloc(ES1_GBUF_MSG_SIZE_MAX, GFP_KERNEL); + if (!buffer) + goto error; + + usb_fill_bulk_urb(urb, udev, + usb_rcvbulkpipe(udev, es1->cport_in_endpoint), + buffer, ES1_GBUF_MSG_SIZE_MAX, + cport_in_callback, hd); + es1->cport_in_urb[i] = urb; + es1->cport_in_buffer[i] = buffer; + retval = usb_submit_urb(urb, GFP_KERNEL); + if (retval) + goto error; + } + + /* 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; + + es1->cport_out_urb[i] = urb; + es1->cport_out_urb_busy[i] = false; /* just to be anal */ + } + + return 0; +error: + ap_disconnect(interface); + + return retval; +} + +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 "); -- 2.7.4