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mcp2210-core.c
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mcp2210-core.c
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/*
* MCP2210 driver
*
* Copyright (c) 2013 Daniel Santos <[email protected]>
* 2013 Mathew King <[email protected]> for Trilithic, Inc
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*
* TODO:
* Incomplete list:
* - major number from maintainer?
* - honor cs_gpio and allow SPI where idle_cs == active_cs
* - missing mechanism to notify external entities of changes to gpio and
* the dedicated "interrupt counter" line.
* - honor cs_change
*
* Fix list:
* - While we wont see it on x86 & little-endian arm, the flipping
* ctl_complete_urb() may be broken when processing data from the request
* buffer.
* - Using the packed version of protocol structs is bloating code horribly,
* even worse than I had guessed it would!! So we need to have packed and
* unpacked versions of these structs replace the is_mcp_endianness and
* "flipping" functionality with conversions from packed (protocol-correct)
* little-endian structs to unpacked native-endianness structs.
* - When a command dies and can't be retried, we need to do something more
* than just log it. Re-implement device failure?
* - Change ioctl to netlink.
* - ioctl interface not friendly with ABIs where kernel & user space have
* different sized ptrs (x32, sparc64, etc.) (Maybe fix this when we convert
* to netlink)
* - obey struct spi_transfer cs_change
*
* Tweak list:
* - examine locking and possibly (hopefully) refine
* - better prediction of how long SPI transfers will take and appropriate
* scheduling so that we don't unnecessarily request a status (update: this
* has some stuff now, but it may need an audit)
* - include/linux/spi/spi.h: extend mode (to u16), spi_device, et. al. to
* accommodative missing features (timing, drop cs between words, etc.) (note
* current work with DUAL and QUAD on linux-spi)
* - update spidev driver & userspace to support
* - update mcp2210 driver to use them.
*
* @file
*
* Product page:
* https://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en556614
* Datasheet:
* https://www.microchip.com/downloads/en/DeviceDoc/22288A.pdf
*
* Background:
*
* The MCP2210 is a USB-to-SPI protocol converter with GPIO by Microchip. It
* uses a basic 64-byte request/response protocol for all operations, advertises
* its self as a generic HID device and can be used via the hid-generic driver
* from userspace using the hidraw /dev node. A more friendly interface is
* available via Kerry Wong's MCP2210-Library
* (https://github.com/kerrydwong/MCP2210-Library) which is built on top of
* Signal 11's hidapi library (http://www.signal11.us/oss/hidapi) which in turn
* uses libusb. All together, it gives you a pretty user-friendly userland
* interface to to the device, but carries the following drawbacks:
*
* - Extensive overhead: hid-core driver -> usbhid driver -> (hid-generic
* driver) -> libusb -> hidapi -> MCP2210-Library means lots of memory & CPU.
* (Note however that hid-generic is virtually non-existent.) Additionally,
* an embedded system will have to enable the input and HID layers that it
* otherwise may not require.
* - No way to use SPI protocol drivers to manage peripherals on the other side
* of the MCP2210.
* - No mechanism for auto-configuration outside of userland.
*
* This driver attempts to solve these shortcomings by eliminating all of these
* layers, including the kernel's input, hid, hid-core, usbhid, etc.,
* communicating with the MCP2210 directly via interrupt URBs and allowing your
* choice of spi protocol driver for each SPI device, with the standard option
* of spidev for interacting with the SPI device from userspace. In addition,
* it supplies an (optional) auto-configuration * scheme which utilizes the
* devices 256 bytes of user EEPROM to store the wiring * information for the
* board and a fairly complete ioctl interface for userland * configuration,
* testing and such.
*
* Theory of Operation:
* ===================
*
* Commands and The Command Queue
* ------------------------------
* The MCP2210 driver is a queue-driven USB interface driver. All commands are
* executed (or given the opportunity) serially, in FIFO order. Only one
* command may execute at a time. Each command represents a logically atomic
* operation (e.g., send SPI transfer or query settings) and (typically)
* exchanges at least one message with the device via via interrupt URBs.
*
* Commands are objects of either struct mcp2210_cmd or a derived-type using
* pseudo-inheritance -- embedding a struct mcp2210_cmd object as its first
* member and using a type field to specify the command type. There are three
* different types of "normal" commands that interact with the device directly.
* Each populate the cmd->type with a pointer to an appropriate struct
* mcp2210_cmd_type object:
*
* 1. Transfer SPI messages (mcp2210-spi.c)
* 2. Read/write to/from the device's user-EEPROM area (mcp2210-eeprom.c)
* 3. Query and change settings (mcp2210-ctl.c)
*
* General-purpose commands have have a NULL command type, but will populate
* cmd->complete and cmd->context to defer some work, possibly to execute in a
* non-atomic context. Currently, these are only used to probe spi and gpio,
* neither of which can be probed at the time the USB interface is probed
* because the information to do so is not yet available. This occurs either
* when the user- EEPROM area has been read and decoded (when
* CONFIG_MCP2210_CREEK is enabled) or when the configure ioctl command is
* called from userspace.
*
* Delayed & Non-Atomic Commands
* -----------------------------
* Due to the nature of the device, having:
*
* 1. a single USB interface,
* 2. potentially multiple SPI peripherals connected to it,
* 3. the need to poll its gpio values & interrupt counter, and
* 4. late arrival of wiring information to perform a complete probe (with SPI
* & GPIO),
*
* the driver requires a slightly more sophisticated mechanism for processing
* commands than a simple FIFO queue processed by URB completion handlers.
* Polling commands need to be delayed. SPI Transfers (especially on slower
* chips) often need to have delays between URBs to give the device time to
* complete transfers to the chip. Performing the configure (probing spi_master
* and gpio_chip) must occur in a context that can sleep. If a command needs to
* be delayed, its cmd->delayed bit is set and cmd->delay_until will specify a
* time (in jiffies) that the command is to run at. If the command must be able
* to sleep, it's cmd->nonatomic bit will be set.
*
* Note that there is no mechanism (at this time) to assure that a delayed
* command will execute at its requested time, although it is guaranteed not
* to execute prior to it. Delayed commands who's cmd->delay_until time has
* been reached still have to wait their turn in the queue to be eligible for
* execution. If a delayed command is popped from the queue but its
* cmd->delay_until time has not yet arrived, it is moved to the
* dev->delayed_list and an appropriate mechanism (either timer or
* delayed_work) is set to pick it up. If another command is executing when
* the timer expires or delayed_work runs, the delayed command is (effectively)
* moved to the head of the queue and will execute next.
*
* process_commands():
* ------------------
* Messages in the queue are processed via process_commands(). If dev->cur_cmd
* is NULL, it will attempt to retrieve a command from the queue, marking its
* state as new. How it processes commands differs between "normal" commands
* (which interact with the MCP2210) and general-purpose commands (which are
* simply some delayed work)
*
* -- Normal Commands
* If there is a normal command in the new state, submit_urbs() is called and
* its state is set to "submitted". Completion handlers for the in and out URBs
* will eventually be called (if the usb host driver behaves) marking the
* command as "completed" and calling process_commands() to have the completed
* command finalized. Finalization is performed by calling struct mcp2210_cmd's
* complete function (if non-NULL) and freeing it. Then, the next message is
* retrieved, and so forth.
*
* -- General-Purpose Commands
* For general-purpose commands, submit/complete_urbs() is bypassed and it is
* instead immediately marked as completed having its complete() function
* called, allowing any arbitrary work to be performed.
*
* -- Deferred Work
* A command may be deferred because:
* a. it needs to wait before starting,
* c. it needs to run again, but needs to wait before doing so, or
* b. it needs to run in a non-atomic state.
*
* submit_urbs():
* -------------
* This function will first call the command type's submit_prepare() function,
* which should perform any needed initialization, populate the 64-byte request
* message and return non-zero unless it has an error. However, there are two
* exceptions to this: submit_prepare() may return -ERESTARTSYS to have the
* command deleted w/o further processing or -EAGAIN to have the message
* restarted and submit_urbs() called again). It will then submit the URBS and
* change the command's state to "submitted".
*
* complete_urb():
* This function manages both the in & out URBs.
*
* Once both URBs have completed,
* the command type's complete_urb() function is called and the command's
* state is set to "completed".
*
#if 0
out of date info:
* When the in URB completes, complete_urb_in() performs the following:
* - basic sanity checks & URB status via check_urb_status()
* - sets command status to "sent"
* - calls the command type's complete_tx() function (if it has one)
*
* complete_urb_out():
* Similarly, when the out URB completes, complete_urb_out() performs
* the following:
* - calls check_urb_status() and exits upon error
* - checks for and handles out-of-order responses
* - sets the command status to "done"
* - checks the status field and general validity of the response message via
* check_response().
* - calls complete_rx()
* - if complete_rx() returns -EAGAIN, the command's state is reset to "new" so
* that the next call to process_commands will run it again.
* - calls process_commands() (in GFP_ATOMIC mode) to process the next command.
#endif
*
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/workqueue.h>
#include <linux/uaccess.h>
//#include <linux/completion.h>
#include "mcp2210.h"
#include "mcp2210-debug.h"
#ifdef CONFIG_MCP2210_CREEK
# include "mcp2210-creek.h"
#endif /* CONFIG_MCP2210_CREEK */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,34)
# define HAVE_USB_ALLOC_COHERENT 1
#endif
static void mcp2210_delete(struct kref *kref);
static int mcp2210_probe(struct usb_interface *intf,
const struct usb_device_id *id);
static void mcp2210_disconnect(struct usb_interface *intf);
static int report_status_error(struct mcp2210_device *dev, u8 status);
static bool reschedule_delayed_work(struct mcp2210_device *dev,
unsigned long _jiffies);
static inline bool reschedule_delayed_work_ms(struct mcp2210_device *dev,
unsigned int ms);
static void delayed_work_callback(struct work_struct *work);
static void timer_callback(unsigned long context);
static int unlink_urbs(struct mcp2210_device *dev);
static void kill_urbs(struct mcp2210_device *dev, unsigned long *irqflags);
static void complete_urb(struct urb *urb);
static int submit_urbs(struct mcp2210_cmd *cmd, gfp_t gfp_flags);
struct mcp2210_cmd_type mcp2210_cmd_types[MCP2210_CMD_TYPE_MAX];
/******************************************************************************
* Module parameters
*/
int debug_level = CONFIG_MCP2210_DEBUG_INITIAL;
int creek_enabled = IS_ENABLED(CONFIG_MCP2210_CREEK);
int dump_urbs = IS_ENABLED(CONFIG_MCP2210_DEBUG);
int dump_commands = IS_ENABLED(CONFIG_MCP2210_DEBUG_VERBOSE);
uint pending_bytes_wait_threshold = 45;
module_param(debug_level, int, 0664);
module_param(creek_enabled, int, 0664);
module_param(dump_urbs, int, 0664);
module_param(dump_commands, int, 0664);
module_param(pending_bytes_wait_threshold, uint, 0664);
/******************************************************************************
* USB Driver structs
*/
static const struct usb_device_id mcp2210_devices[] = {
{ USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2210)},
{ }
};
static struct usb_driver mcp2210_driver = {
.name = "mcp2210",
.probe = mcp2210_probe,
.disconnect = mcp2210_disconnect,
.suspend = NULL,
.resume = NULL,
.reset_resume = NULL,
.id_table = mcp2210_devices,
.supports_autosuspend = IS_ENABLED(CONFIG_MCP2210_AUTOPM),
};
/******************************************************************************
* Module functions
*/
static int __init mcp2210_init(void)
{
int ret;
printk("mcp2210_init\n");
msg_validate_size();
ret = usb_register_driver(&mcp2210_driver, THIS_MODULE, "mcp2210");
if (ret)
printk(KERN_ERR "can't register mcp2210 driver\n");
return ret;
}
static void __exit mcp2210_exit(void)
{
printk("mcp2210_exit\n");
usb_deregister(&mcp2210_driver);
}
module_init(mcp2210_init);
module_exit(mcp2210_exit);
MODULE_AUTHOR("Daniel Santos <[email protected]>");
MODULE_DESCRIPTION("Microchip MCP2210 USB-to-SPI protocol converter with GPIO");
MODULE_LICENSE("GPL");
/* TODO: I have no idea what this should say, this shouldn't be a "platform:"
* device if I understand correctly */
MODULE_ALIAS("mcp2210");
/******************************************************************************
* USB Class Driver & file ops
*/
static inline struct mcp2210_device *mcp2210_kref_to_dev(struct kref *kref)
{
return container_of(kref, struct mcp2210_device, kref);
}
#ifdef CONFIG_MCP2210_IOCTL
static int mcp2210_open(struct inode *inode, struct file *file)
{
struct mcp2210_device *dev;
struct usb_interface *intf;
int subminor = iminor(inode);
int ret;
if (!(intf = usb_find_interface(&mcp2210_driver, subminor))) {
pr_err("%s - error, can't find device for minor %d\n",
__func__, subminor);
return -ENODEV;
}
if (!(dev = usb_get_intfdata(intf)))
return -ENODEV;
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM)) {
ret = usb_autopm_get_interface(intf);
if (ret && ret != -EACCES) {
mcp2210_err("usb_autopm_get_interface() failed:%de", ret);
return ret;
}
}
kref_get(&dev->kref);
file->private_data = dev;
return 0;
}
static int mcp2210_release(struct inode *inode, struct file *file)
{
struct mcp2210_device *dev = file->private_data;
if (!dev)
return -ENODEV;
/* allow the device to be autosuspended */
mutex_lock(&dev->io_mutex);
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM) && dev->intf)
usb_autopm_put_interface(dev->intf);
mutex_unlock(&dev->io_mutex);
/* decrement the count on our device */
kref_put(&dev->kref, mcp2210_delete);
return 0;
}
static int mcp2210_flush (struct file *file, fl_owner_t id)
{
return 0;
}
static loff_t mcp2210_no_llseek (struct file *file, loff_t offset, int i)
{
return -EPERM;
}
static ssize_t mcp2210_no_read_write (struct file *file,
const char __user *data, size_t size,
loff_t *offset)
{
return -EPERM;
}
const struct file_operations mcp2210_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = mcp2210_ioctl,
.compat_ioctl = mcp2210_ioctl,
.llseek = mcp2210_no_llseek,
.read = (void*)mcp2210_no_read_write,
.write = mcp2210_no_read_write,
.open = mcp2210_open,
.flush = mcp2210_flush,
.release = mcp2210_release,
};
static struct usb_class_driver mcp2210_class = {
.name = "usb2spi_bridge%d",
.fops = &mcp2210_fops,
.minor_base = 0, /* FIXME: need a minor base from USB maintainer? */
};
#endif /* CONFIG_MCP2210_IOCTL */
/******************************************************************************
* USB Driver functions
*/
static inline void reset_endpoint(struct mcp2210_endpoint *ep)
{
ep->state = MCP2210_STATE_NEW;
ep->kill = 0;
}
/* init_endpoint - Initialize an endpoint proxy struct
*
* may sleep
*
* This is only called from one place now but the code is cleaner with it
* separated out in another function, so I'm marking inlining it for the
* possible reduction in size. (It's only called in probe, so performance isn't
* a big deal here.)
*/
static __always_inline int init_endpoint(struct mcp2210_device *dev,
const struct usb_host_endpoint *ep)
{
int is_dir_in = !!usb_endpoint_dir_in(&ep->desc);
struct mcp2210_endpoint *dest = &dev->eps[is_dir_in];
unsigned int pipe;
struct urb *urb;
if (is_dir_in)
pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
else
pipe = usb_sndintpipe(dev->udev, ep->desc.bEndpointAddress);
/* just another struct size sanity check */
BUILD_BUG_ON(sizeof(*dest->buffer) != 64);
if (unlikely(dest->ep)) {
mcp2210_warn("Unexpected: more than one interrupt %s endpoint "
"discovered, ingoring them\n",
urb_dir_str[is_dir_in]);
return 0;
}
dest->is_dir_in = is_dir_in;
dest->ep = ep;
reset_endpoint(dest);
//= ATOMIC_INIT(0);
atomic_set(&dest->unlink_in_process, 1);
urb = usb_alloc_urb(0, GFP_KERNEL);
if (unlikely(!urb)) {
mcp2210_err("Failed to alloc %s URB\n", urb_dir_str[is_dir_in]);
return -ENOMEM;
}
/* If we have usb_alloc_coherent, we'll use that. Otherwise, we'll let
* the usb host controller driver allocate a DMA buffer if it needs one
*/
#ifdef HAVE_USB_ALLOC_COHERENT
dest->buffer = usb_alloc_coherent(dev->udev, 64, GFP_KERNEL,
&urb->transfer_dma);
urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
#else
dest->buffer = kzalloc(64, GFP_KERNEL);
#endif
if (unlikely(!dest->buffer)) {
usb_free_urb(urb);
mcp2210_err("Failed to alloc %s URB DMA buffer\n",
urb_dir_str[is_dir_in]);
return -ENOMEM;
}
dest->urb = urb;
usb_fill_int_urb(urb,
dev->udev,
pipe,
dest->buffer,
64,
complete_urb,
dev,
ep->desc.bInterval);
/* well, this isn't really helpful, but usb_host_endpoint ptr will
* eventually replace pipe and usb_submit_urb() will have to
* populate this later anyway */
urb->ep = (struct usb_host_endpoint*)ep;
#if 0
/* apparently, this isn't reliable on all host controllers, so we'll
* just check acutal_length ourselves */
if (is_dir_in)
urb->transfer_flags |= URB_SHORT_NOT_OK;
#endif
return 0;
}
static void mcp2210_delete(struct kref *kref)
{
struct mcp2210_device *dev = mcp2210_kref_to_dev(kref);
struct mcp2210_endpoint *ep;
for (ep = dev->eps; ep < &dev->eps[2]; ++ep) {
if (ep->urb) {
if (ep->buffer)
#ifdef HAVE_USB_ALLOC_COHERENT
usb_free_coherent(dev->udev, 64, ep->buffer,
ep->urb->transfer_dma);
#else
kfree(ep->buffer);
#endif
usb_free_urb(ep->urb);
}
}
if (dev->config)
kfree(dev->config);
kfree(dev);
}
#ifdef CONFIG_MCP2210_CREEK
static int creek_configure(struct mcp2210_cmd *cmd, void *context) {
struct mcp2210_device *dev = cmd->dev;
struct mcp2210_board_config *board_config;
int ret;
board_config = mcp2210_creek_probe(dev, GFP_KERNEL);
BUG_ON(dev->config);
if (IS_ERR(board_config)) {
mcp2210_err("Failed to decode board config from MCP2210's user-EEPROM: %de", (int)PTR_ERR(board_config));
return 0;
}
ret = mcp2210_configure(dev, board_config);
/*
spin_lock_irqsave(&dev->eeprom_spinlock, irqflags);
magic = le32_to_cpu(*((u32*)dev->eeprom_cache));
spin_unlock_irqrestore(&dev->eeprom_spinlock, irqflags);
*/
return 0;
}
static int eeprom_read_complete(struct mcp2210_cmd *cmd_head, void *context)
{
struct mcp2210_device *dev = context;
struct mcp2210_cmd_eeprom *cmd = (void *)cmd_head;
unsigned long irqflags;
int ret;
mcp2210_debug();
BUG_ON(!cmd);
BUG_ON(!dev);
BUG_ON(!cmd_head->type);
BUG_ON(cmd_head->type->id != MCP2210_CMD_TYPE_EEPROM);
/* deal with fuck-ups */
if (cmd->head.status) {
mcp2210_err("RPi USB otg drivers are shit, trying "
"a-fucking-gain...");
ret = mcp2210_eeprom_read(dev, NULL, 0, cmd->size,
eeprom_read_complete, dev,
GFP_ATOMIC);
if (ret && ret != -EINPROGRESS)
mcp2210_err("Adding eeprom command failed with %de, fuck it", ret);
return 0;
}
/* We can get 0xfa (write failure) for writing to EEPROM, but we
* supposedly can't get a failure for reading, so we pertty much should
* always have a zero for the mcpstatus
*/
if (cmd->head.mcp_status) {
mcp2210_err("Unexpected failure of EEPROM read: 0x%02x",
cmd->head.mcp_status);
return 0;
}
if (cmd->size == 4) {
u8 magic[4];
spin_lock_irqsave(&dev->eeprom_spinlock, irqflags);
memcpy(magic, dev->eeprom_cache, 4);
//magic = le32_to_cpu(*((u32*)dev->eeprom_cache));
spin_unlock_irqrestore(&dev->eeprom_spinlock, irqflags);
if (memcmp(magic, CREEK_CONFIG_MAGIC, 4)) {
mcp2210_notice("creek magic not detected: 0x%08x != "
"0x%08x", *(u32*)magic, *(u32*)CREEK_CONFIG_MAGIC);
return 0;
}
mcp2210_notice("creek magic detected, reading config from EEPROM");
ret = mcp2210_eeprom_read(dev, NULL, 0, 0x100, eeprom_read_complete, dev, GFP_ATOMIC);
if (ret && ret != -EINPROGRESS)
mcp2210_err("Adding eeprom command failed with %de",
ret);
return 0;
} else if (cmd->size == 0x100) {
struct mcp2210_cmd *cmd;
if (!dev->s.have_power_up_chip_settings) {
mcp2210_err("Don't have power up chip settings, aborting probe... :(");
return 0;
}
cmd = mcp2210_alloc_cmd(dev, NULL, sizeof(struct mcp2210_cmd), GFP_ATOMIC);
if (!cmd) {
mcp2210_err("mcp2210_alloc_cmd failed (ENOMEM)");
return 0;
}
cmd->complete = creek_configure;
cmd->nonatomic = 1;
ret = mcp2210_add_cmd(cmd, true);
if (ret)
return 0;
}
#if 0
if (ret && ret != -EINPROGRESS) {
mcp2210_err("Adding eeprom command failed with %de", ret);
goto error2;
}
CREEK_CONFIG_MAGIC
le32_to_cpu(creek_get_bits(&bs, 32));
/* HACK: This is a hack for when URBs fail on the rpi, since we're not
* really even using these yet */
dev->have_power_up_chip_settings = 1;
dev->have_power_up_spi_settings = 1;
dev->do_spi_probe = 1;
#endif
return 0;
}
#else
static inline int eeprom_read_complete(struct mcp2210_cmd *cmd_head,
void *context)
{
return 0;
}
#endif /* CONFIG_MCP2210_CREEK */
/* mcp2210_probe
* can sleep, but keep it minimal as the USB core uses a single thread to probe
* & remove all USB devices.
*/
int mcp2210_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_host_interface *intf_desc = intf->cur_altsetting;
struct mcp2210_device *dev;
struct usb_host_endpoint *ep, *ep_end;
int ret = -ENODEV;
printk("mcp2210_probe\n");
if (!udev)
return -ENODEV;
dev = kzalloc(sizeof(struct mcp2210_device), GFP_KERNEL);
if (unlikely(!dev)) {
mcp2210_err("failed to allocate struct usb_device (%u bytes)",
(unsigned)sizeof(struct mcp2210_device));
return -ENOMEM;
}
dev->intf = intf;
dev->udev = udev;
kref_init(&dev->kref);
INIT_LIST_HEAD(&dev->cmd_queue);
INIT_LIST_HEAD(&dev->delayed_list);
spin_lock_init(&dev->dev_spinlock);
spin_lock_init(&dev->queue_spinlock);
#ifdef CONFIG_MCP2210_EEPROM
spin_lock_init(&dev->eeprom_spinlock);
#endif
mutex_init(&dev->io_mutex);
ctl_cmd_init(dev, &dev->ctl_cmd, 0, 0, NULL, 0, false);
INIT_DELAYED_WORK(&dev->delayed_work, delayed_work_callback);
init_timer(&dev->timer);
dev->timer.function = timer_callback;
dev->timer.data = (unsigned long)dev;
#ifdef CONFIG_MCP2210_DEBUG
atomic_set(&dev->manager_running, 0);
#endif
#ifdef CONFIG_MCP2210_GPIO
#endif
#ifdef CONFIG_MCP2210_SPI
/* mark current spi config as uninitialized */
dev->s.cur_spi_config = -1;
#endif
/* Set up interrupt endpoint information. */
ep_end = &intf_desc->endpoint[intf_desc->desc.bNumEndpoints];
for (ep = intf_desc->endpoint; ep != ep_end; ++ep) {
if (!usb_endpoint_xfer_int(&ep->desc))
continue;
if ((ret = init_endpoint(dev, ep)))
goto error_kref_put;
}
if (unlikely(!dev->eps[EP_OUT].ep || !dev->eps[EP_IN].ep)) {
mcp2210_err("could not find in and/or out interrupt endpoints");
goto error_kref_put;
}
usb_set_intfdata(intf, dev);
/* no sleeping until we're done with all of our probing */
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM))
usb_autopm_get_interface_no_resume(intf);
#ifdef CONFIG_MCP2210_IOCTL
/* TODO: Do I need a "major number" from maintainer?
* https://www.kernel.org/doc/htmldocs/usb/API-usb-register-dev.html
*/
ret = usb_register_dev(intf, &mcp2210_class);
if (unlikely(ret)) {
mcp2210_err("failed to register device %de\n", ret);
goto error_autopm_put;
}
#endif /* CONFIG_MCP2210_IOCTL */
/* TODO: set USB power to max until we know how much we need? */
dump_dev(KERN_INFO, 0, "This is the initial device state: ", dev);
/* Submit initial commands & queries. First, we have to cancel any SPI
* messages that were started (and not finished) prior the host machine
* rebooting since the chip fails to do this upon USB reset. */
if ((ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_SPI_CANCEL, 0,
NULL, 0, false, GFP_KERNEL))
/* current chip configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_CHIP_CONFIG, 0,
NULL, 0, false, GFP_KERNEL))
/* current SPI configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_SPI_CONFIG, 0,
NULL, 0, false, GFP_KERNEL))
/* power-up chip configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_NVRAM,
MCP2210_NVRAM_SPI,
NULL, 0, false, GFP_KERNEL))
/* power-up SPI configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_NVRAM,
MCP2210_NVRAM_CHIP,
NULL, 0, false, GFP_KERNEL))
/* user key parameters */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_NVRAM,
MCP2210_NVRAM_KEY_PARAMS,
NULL, 0, false, GFP_KERNEL))) {
mcp2210_err("Adding some command failed with %de", ret);
goto error_deregister_dev;
}
if (IS_ENABLED(CONFIG_MCP2210_CREEK) && creek_enabled) {
/* read the first 4 bytes to see if we have our magic number */
ret = mcp2210_eeprom_read(dev, NULL, 0, 4, eeprom_read_complete, dev, GFP_KERNEL);
if (ret && ret != -EINPROGRESS) {
mcp2210_err("Adding eeprom command failed with %de", ret);
goto error_deregister_dev;
}
}
/* start up background cleanup thread */
schedule_delayed_work(&dev->delayed_work, msecs_to_jiffies(1000));
/* Submit the first command's URB */
ret = process_commands(dev, false, true);
if (ret < 0)
goto error_deregister_dev;
mcp2210_info("success");
return 0;
error_deregister_dev:
if (IS_ENABLED(CONFIG_MCP2210_IOCTL))
usb_deregister_dev(intf, &mcp2210_class);
error_autopm_put:
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM))
usb_autopm_put_interface(intf);
usb_set_intfdata(intf, NULL);
error_kref_put:
kref_put(&dev->kref, mcp2210_delete);
return ret;
}
#if 0
static void fail_device(struct mcp2210_device *dev, int error)
{
mcp2210_err("failing mcp2210 with error %de", error);
*((volatile int *)&dev->dead) = 1;
unlink_urbs(dev);
cancel_delayed_work(&dev->delayed_work);
dev->cur_cmd->status = error;
}
#endif
/**
* eats new_config
*/
int mcp2210_configure(struct mcp2210_device *dev, struct mcp2210_board_config *new_config)
{
unsigned i;
struct mcp2210_chip_settings chip_settings;
int ret;
might_sleep();
if (IS_ENABLED(CONFIG_MCP2210_DEBUG)) {
BUG_ON(dev->spi_master);
BUG_ON(dev->s.is_gpio_probed);
BUG_ON(dev->config);
BUG_ON(!dev->s.have_chip_settings);
}
if (dev->config)
mcp2210_err("ERROR: already have dev->config!");
if (dev->spi_master)
mcp2210_err("ERROR: already have dev->spi_master!");
if (dev->s.is_gpio_probed)
mcp2210_err("ERROR: gpio already probed");
if (!dev->s.have_chip_settings)
mcp2210_err("ERROR: don't have dev->s.have_chip_settings!");
if (dev->config || dev->spi_master || dev->s.is_gpio_probed || !dev->s.have_chip_settings)
return -EPERM;
dev->s.cur_spi_config = -1;
dev->s.have_config = 1;
dev->config = new_config;
memcpy(&chip_settings, &dev->s.chip_settings, sizeof(chip_settings));
for (i = 0; i < MCP2210_NUM_PINS; ++i) {
u8 mode = dev->config->pins[i].mode;
chip_settings.pin_mode[i] = mode;
dev->names[i] = dev->config->pins[i].name;
}
mcp2210_add_ctl_cmd(dev, MCP2210_CMD_SET_CHIP_CONFIG, 0, &chip_settings,
sizeof(chip_settings), false, GFP_KERNEL);
if (IS_ENABLED(CONFIG_MCP2210_GPIO)) {
mcp2210_info("----------probing GPIO----------\n");
ret = mcp2210_gpio_probe(dev);
if (ret) {
mcp2210_err("gpio probe failed: %de", ret);
return 0;
}
}
if (IS_ENABLED(CONFIG_MCP2210_IRQ)) {
mcp2210_info("----------probing IRQ controller----------\n");
ret = mcp2210_irq_probe(dev);
if (ret) {
mcp2210_err("IRQ probe failed: %de", ret);
return 0;
}
}
if (IS_ENABLED(CONFIG_MCP2210_SPI)) {
mcp2210_info("----------probing SPI----------\n");
ret = mcp2210_spi_probe(dev);
if (ret) {
mcp2210_err("spi probe failed: %de", ret);
return 0;
}
}
if (!dev->cur_cmd)
process_commands(dev, false, true);
/* Allow the device to auto-sleep now */
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM))
usb_autopm_put_interface(dev->intf);
if (IS_ENABLED(CONFIG_MCP2210_DEBUG)) {
mcp2210_info("----------new dump----------\n");
dump_dev(KERN_INFO, 0, "", dev);
}
mcp2210_notice("Configure successful");
return 0;
}
// can sleep, like probe
void mcp2210_disconnect(struct usb_interface *intf)
{
unsigned long irqflags;
int ret;
struct mcp2210_device *dev = usb_get_intfdata(intf);
printk("mcp2210_disconnect\n");
*((volatile int *)&dev->dead) = -ESHUTDOWN;
spin_lock_irqsave(&dev->dev_spinlock, irqflags);
cancel_delayed_work(&dev->delayed_work);
del_timer(&dev->timer);
spin_unlock_irqrestore(&dev->dev_spinlock, irqflags);
/* disable interrupt generation early */
mcp2210_irq_remove(dev);
/* unlink any URBs in route and wait for their completion handlers to be
* called */
mcp2210_info("unlinking and killing all URBs...");
kill_urbs(dev, NULL);
mcp2210_info("emptying command queue...");
spin_lock_irqsave(&dev->queue_spinlock, irqflags);
while (!list_empty(&dev->cmd_queue)) {
struct mcp2210_cmd *cmd = list_first_entry(&dev->cmd_queue,
struct mcp2210_cmd,
node);
list_del(dev->cmd_queue.next);
if (cmd->complete) {
cmd->status = -ESHUTDOWN;
spin_unlock(&dev->queue_spinlock);
mcp2210_debug("calling completion handler for %p", cmd);
ret = cmd->complete(cmd, cmd->context);
mcp2210_debug("done");
spin_lock(&dev->queue_spinlock);
} else
ret = 0;
if (ret != -EINPROGRESS)
kfree(cmd);
};
spin_unlock_irqrestore(&dev->queue_spinlock, irqflags);
/* always let completion handler free dev->cur_cmd */
/* TODO: interrupt (? taken care of by interrupting URBs?) any SPI
* transfers & clear the queues */
/* TODO: put USB port power back to whatever "normal" is */
#ifdef CONFIG_MCP2210_SPI
if (dev->spi_master)
mcp2210_spi_remove(dev);
#endif
#ifdef CONFIG_MCP2210_GPIO
if (dev->s.is_gpio_probed)
mcp2210_gpio_remove(dev);
#endif
/* TODO: free GPIO resources here */