I'm playing around with a PIC based project at home (not an Intel
activity) and found I needed a usb driver to talk to the boot loader
so I can program my USB Bitwhacker with new custom firmware. The
following adds the pic18bl driver to the kernel. Its pretty simple
and is somewhat based on bits of a libusb driver that does some of
what this driver does.
What do you think?
--mgross
Singed-off-by: Mark Gross <[email protected]>
---
Index: linux-2.6.24-rc6/drivers/usb/misc/pic18bl.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.24-rc6/drivers/usb/misc/pic18bl.c 2007-12-29 11:21:14.000000000 -0800
@@ -0,0 +1,627 @@
+/*
+ * PIC18 usb boot loader driver based on the MicroChip firmware, and a user
+ * mode libusb driver that does some of the same operations only different.
+ * Based on the skeleton driver
+ *
+ * --mgross
+ *
+ * USB Skeleton driver - 2.2
+ *
+ * Copyright (C) 2001-2004 Greg Kroah-Hartman ([email protected])
+ *
+ * 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, version 2.
+ *
+ * This driver is based on the 2.6.3 version of drivers/usb/usb-pic18bleton.c
+ * but has been rewritten to be easier to read and use.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kref.h>
+#include <asm/uaccess.h>
+#include <linux/usb.h>
+#include <linux/mutex.h>
+
+/* Define these values to match your devices */
+#define USB_PIC18BL_VENDOR_ID 0x04d8
+#define USB_PIC18BL_PRODUCT_ID 0x000b
+
+/* table of devices that work with this driver */
+static struct usb_device_id pic18bl_table [] = {
+ { USB_DEVICE(USB_PIC18BL_VENDOR_ID, USB_PIC18BL_PRODUCT_ID) },
+ { } /* Terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, pic18bl_table);
+
+
+/* Get a minor range for your devices from the usb maintainer */
+#define USB_PIC18BL_MINOR_BASE 192
+
+/* our private defines. if this grows any larger, use your own .h file */
+#define MAX_TRANSFER (PAGE_SIZE - 512)
+/* MAX_TRANSFER is chosen so that the VM is not stressed by
+ allocations > PAGE_SIZE and the number of packets in a page
+ is an integer 512 is the largest possible packet on EHCI */
+#define WRITES_IN_FLIGHT 8
+/* arbitrarily chosen */
+
+/* structs and information based on boot loader firmware */
+#define BOOT_EP_SIZE 64
+#define OVER_HEAD 5 /*Overhead: <CMD_CODE><LEN><ADDR:3>*/
+#define DATA_SIZE (BOOT_EP_SIZE - OVER_HEAD)
+
+#define READ_VERSION 0x00
+#define READ_FLASH 0x01
+#define WRITE_FLASH 0x02
+#define ERASE_FLASH 0x03
+#define READ_EEDATA 0x04
+#define WRITE_EEDATA 0x05
+#define READ_CONFIG 0x06
+#define WRITE_CONFIG 0x07
+#define UPDATE_LED 0x32
+#define RESET 0xFF
+
+struct address {
+ u8 low;
+ u8 high;
+ u8 upper;
+} __attribute__ ((packed));
+
+union boot_data_buffer {
+ u8 buffer[BOOT_EP_SIZE];
+ struct {
+ u8 cmd;
+ u8 len;
+ struct address addr;
+ u8 data[DATA_SIZE];
+ } __attribute__ ((packed)) data;
+ struct {
+ u8 cmd; /* should always == 32 */
+ u8 led_num; /* should only be 3 or 4 */
+ u8 led_status;
+ } __attribute__ ((packed)) led;
+};
+
+
+/* Structure to hold all of our device specific stuff */
+struct usb_pic18bl {
+ struct usb_device *udev;
+ struct usb_interface *interface;
+ struct semaphore limit_sem;
+ struct usb_anchor submitted;
+ unsigned char *bulk_in_buffer;
+ size_t bulk_in_size;
+ __u8 bulk_in_endpointAddr;
+ __u8 bulk_out_endpointAddr;
+ int errors;
+ int open_count;
+ spinlock_t err_lock;
+ struct kref kref;
+ struct mutex io_mutex;
+};
+#define to_pic18bl_dev(d) container_of(d, struct usb_pic18bl, kref)
+
+static struct usb_driver pic18bl_driver;
+static void pic18bl_draw_down(struct usb_pic18bl *dev);
+
+static void pic18bl_delete(struct kref *kref)
+{
+ struct usb_pic18bl *dev = to_pic18bl_dev(kref);
+
+ usb_put_dev(dev->udev);
+ kfree(dev->bulk_in_buffer);
+ kfree(dev);
+}
+
+static int pic18bl_open(struct inode *inode, struct file *file)
+{
+ struct usb_pic18bl *dev;
+ struct usb_interface *interface;
+ int subminor;
+ int retval = 0;
+
+ subminor = iminor(inode);
+
+ interface = usb_find_interface(&pic18bl_driver, subminor);
+ if (!interface) {
+ err("%s - error, can't find device for minor %d",
+ __FUNCTION__, subminor);
+ retval = -ENODEV;
+ goto exit;
+ }
+
+ dev = usb_get_intfdata(interface);
+ if (!dev) {
+ retval = -ENODEV;
+ goto exit;
+ }
+
+ /* increment our usage count for the device */
+ kref_get(&dev->kref);
+
+ /* lock the device to allow correctly handling errors
+ * in resumption */
+ mutex_lock(&dev->io_mutex);
+
+ if (!dev->open_count++) {
+ retval = usb_autopm_get_interface(interface);
+ if (retval) {
+ dev->open_count--;
+ mutex_unlock(&dev->io_mutex);
+ kref_put(&dev->kref, pic18bl_delete);
+ goto exit;
+ }
+ } else {
+ retval = -EBUSY;
+ dev->open_count--;
+ mutex_unlock(&dev->io_mutex);
+ kref_put(&dev->kref, pic18bl_delete);
+ goto exit;
+ }
+ /* prevent the device from being autosuspended */
+ /* save our object in the file's private structure */
+ file->private_data = dev;
+
+ mutex_unlock(&dev->io_mutex);
+exit:
+ return retval;
+}
+
+static int pic18bl_release(struct inode *inode, struct file *file)
+{
+ struct usb_pic18bl *dev;
+
+ dev = (struct usb_pic18bl *)file->private_data;
+ if (dev == NULL)
+ return -ENODEV;
+
+ /* allow the device to be autosuspended */
+ mutex_lock(&dev->io_mutex);
+ if (!--dev->open_count && dev->interface)
+ usb_autopm_put_interface(dev->interface);
+ mutex_unlock(&dev->io_mutex);
+
+ /* decrement the count on our device */
+ kref_put(&dev->kref, pic18bl_delete);
+ return 0;
+}
+
+static int pic18bl_flush(struct file *file, fl_owner_t id)
+{
+ struct usb_pic18bl *dev;
+ int res;
+
+ dev = (struct usb_pic18bl *)file->private_data;
+ if (dev == NULL)
+ return -ENODEV;
+
+ /* wait for io to stop */
+ mutex_lock(&dev->io_mutex);
+ pic18bl_draw_down(dev);
+
+ /* read out errors, leave subsequent opens a clean slate */
+ spin_lock_irq(&dev->err_lock);
+ res = dev->errors ? (dev->errors == -EPIPE ? -EPIPE : -EIO) : 0;
+ dev->errors = 0;
+ spin_unlock_irq(&dev->err_lock);
+
+ mutex_unlock(&dev->io_mutex);
+
+ return res;
+}
+
+static ssize_t pic18bl_read(struct file *file, char *buffer, size_t count,
+ loff_t *ppos)
+{
+ struct usb_pic18bl *dev;
+ int retval;
+ int bytes_read;
+
+ dev = (struct usb_pic18bl *)file->private_data;
+
+ mutex_lock(&dev->io_mutex);
+ if (!dev->interface) {
+ /* disconnect() was called */
+ retval = -ENODEV;
+ goto exit;
+ }
+
+ /* do a blocking bulk read to get data from the device */
+ retval = usb_bulk_msg(dev->udev,
+ usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
+ dev->bulk_in_buffer,
+ min(dev->bulk_in_size, count),
+ &bytes_read, 10000);
+
+ /* if the read was successful, copy the data to userspace */
+ if (!retval) {
+ if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
+ retval = -EFAULT;
+ else
+ retval = bytes_read;
+ }
+
+exit:
+ mutex_unlock(&dev->io_mutex);
+ return retval;
+}
+
+static void pic18bl_write_bulk_callback(struct urb *urb)
+{
+ struct usb_pic18bl *dev;
+
+ dev = (struct usb_pic18bl *)urb->context;
+
+ /* sync/async unlink faults aren't errors */
+ if (urb->status) {
+ if (!(urb->status == -ENOENT ||
+ urb->status == -ECONNRESET ||
+ urb->status == -ESHUTDOWN))
+ err("%s - nonzero write bulk status received: %d",
+ __FUNCTION__, urb->status);
+
+ spin_lock(&dev->err_lock);
+ dev->errors = urb->status;
+ spin_unlock(&dev->err_lock);
+ }
+
+ /* free up our allocated buffer */
+ usb_buffer_free(urb->dev, urb->transfer_buffer_length,
+ urb->transfer_buffer, urb->transfer_dma);
+ up(&dev->limit_sem);
+}
+
+static ssize_t pic18bl_write(struct file *file, const char *user_buffer,
+ size_t count, loff_t *ppos)
+{
+ struct usb_pic18bl *dev;
+ int retval = -1;
+ struct urb *urb = NULL;
+ union boot_data_buffer *buf = NULL;
+ size_t writesize = min(count, sizeof(union boot_data_buffer));
+ int address = 0;
+
+ dev = (struct usb_pic18bl *)file->private_data;
+
+ /* verify that we actually have some data to write */
+ if (count == 0 || count > sizeof(union boot_data_buffer))
+ goto exit;
+
+ /* limit the number of URBs in flight to stop a user from using up all
+ * RAM
+ */
+ if (down_interruptible(&dev->limit_sem)) {
+ retval = -ERESTARTSYS;
+ goto exit;
+ }
+
+ spin_lock_irq(&dev->err_lock);
+ retval = dev->errors;
+ if (retval < 0) {
+ /* any error is reported once */
+ dev->errors = 0;
+ /* to preserve notifications about reset */
+ retval = (retval == -EPIPE) ? retval : -EIO;
+ }
+ spin_unlock_irq(&dev->err_lock);
+ if (retval < 0)
+ goto error;
+
+ /* create a urb, and a buffer for it, and copy the data to the urb */
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb) {
+ retval = -ENOMEM;
+ goto error;
+ }
+
+ buf = usb_buffer_alloc(dev->udev, writesize, GFP_KERNEL,
+ &urb->transfer_dma);
+ if (!buf) {
+ retval = -ENOMEM;
+ goto error;
+ }
+
+ if (copy_from_user(buf, user_buffer, writesize)) {
+ retval = -EFAULT;
+ goto error;
+ }
+ /* check buffer for invalid noise */
+ address = buf->data.addr.low +
+ 256*(buf->data.addr.high + 256 * buf->data.addr.upper);
+ printk(KERN_ERR "pic18bl_write: writesize = %d cmd = %d, len = %d,\
+ add = 0x%02x%02x%02x\n",writesize, buf->data.cmd, buf->data.len,
+ buf->data.addr.upper, buf->data.addr.high, buf->data.addr.low);
+
+ switch (buf->data.cmd) {
+ /*TODO add more checks for bogus data */
+ /* TODO add code to make read / write transactions impossible to
+ * step on each other. i.e. starting a write transaction while
+ * a read is in flight would be bad.
+ */
+ case READ_VERSION:
+ case RESET:
+ if (buf->data.len + 5 != writesize) {
+ retval = -EINVAL;
+ goto error;
+ }
+ break;
+ case WRITE_FLASH:
+ case ERASE_FLASH:
+ if (address < 0x800) {
+ printk(KERN_ERR "pic18bl: attempt to step on boot "
+ "loader memory blocked by driver \n");
+ retval = -EINVAL;
+ goto error;
+ }
+ case READ_EEDATA:
+ case WRITE_EEDATA:
+ case WRITE_CONFIG:
+ case READ_FLASH:
+ case READ_CONFIG:
+ break;
+ case UPDATE_LED:
+ /* boot.c in the fw code looks like this
+ * command is somewhat of a no-op. perhaps
+ * i should remove this guy????
+ */
+ if (buf->led.led_num != 3 ||
+ buf->led.led_num != 4)
+ goto error;
+
+ default:
+ /*free buf */
+ goto error;
+ }
+
+ /* this lock makes sure we don't submit URBs to gone devices */
+ mutex_lock(&dev->io_mutex);
+ if (!dev->interface) {
+ /* disconnect() was called */
+ mutex_unlock(&dev->io_mutex);
+ retval = -ENODEV;
+ goto error;
+ }
+
+ /* initialize the urb properly */
+ usb_fill_bulk_urb(urb, dev->udev,
+ usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
+ buf, writesize, pic18bl_write_bulk_callback, dev);
+ urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+ usb_anchor_urb(urb, &dev->submitted);
+
+ /* send the data out the bulk port */
+ retval = usb_submit_urb(urb, GFP_KERNEL);
+ mutex_unlock(&dev->io_mutex);
+ if (retval) {
+ err("%s - failed submitting write urb, error %d", __FUNCTION__,
+ retval);
+ goto error_unanchor;
+ }
+
+ /* release our reference to this urb, the USB core will eventually free
+ * it entirely */
+ usb_free_urb(urb);
+
+
+ return writesize;
+
+error_unanchor:
+ usb_unanchor_urb(urb);
+error:
+ if (urb) {
+ usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma);
+ usb_free_urb(urb);
+ }
+ up(&dev->limit_sem);
+
+exit:
+ return retval;
+}
+
+static const struct file_operations pic18bl_fops = {
+ .owner = THIS_MODULE,
+ .read = pic18bl_read,
+ .write = pic18bl_write,
+ .open = pic18bl_open,
+ .release = pic18bl_release,
+ .flush = pic18bl_flush,
+};
+
+/*
+ * usb class driver info in order to get a minor number from the usb core,
+ * and to have the device registered with the driver core
+ */
+static struct usb_class_driver pic18bl_class = {
+ .name = "pic18bl%d",
+ .fops = &pic18bl_fops,
+ .minor_base = USB_PIC18BL_MINOR_BASE,
+};
+
+static int pic18bl_probe(struct usb_interface *interface,
+ const struct usb_device_id *id)
+{
+ struct usb_pic18bl *dev;
+ struct usb_host_interface *iface_desc;
+ struct usb_endpoint_descriptor *endpoint;
+ size_t buffer_size;
+ int i;
+ int retval = -ENOMEM;
+
+ /* allocate memory for our device state and initialize it */
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ err("Out of memory");
+ goto error;
+ }
+ kref_init(&dev->kref);
+ sema_init(&dev->limit_sem, WRITES_IN_FLIGHT);
+ mutex_init(&dev->io_mutex);
+ spin_lock_init(&dev->err_lock);
+ init_usb_anchor(&dev->submitted);
+
+ dev->udev = usb_get_dev(interface_to_usbdev(interface));
+ dev->interface = interface;
+
+ /* set up the endpoint information */
+ /* use only the first bulk-in and bulk-out endpoints */
+ iface_desc = interface->cur_altsetting;
+ for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+ endpoint = &iface_desc->endpoint[i].desc;
+
+ if (!dev->bulk_in_endpointAddr &&
+ usb_endpoint_is_bulk_in(endpoint)) {
+ /* we found a bulk in endpoint */
+ buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
+ dev->bulk_in_size = buffer_size;
+ dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
+ dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
+ if (!dev->bulk_in_buffer) {
+ err("Could not allocate bulk_in_buffer");
+ goto error;
+ }
+ }
+
+ if (!dev->bulk_out_endpointAddr &&
+ usb_endpoint_is_bulk_out(endpoint)) {
+ /* we found a bulk out endpoint */
+ dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
+ }
+ }
+ if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
+ err("Could not find both bulk-in and bulk-out endpoints");
+ goto error;
+ }
+
+ /* save our data pointer in this interface device */
+ usb_set_intfdata(interface, dev);
+
+ /* we can register the device now, as it is ready */
+ retval = usb_register_dev(interface, &pic18bl_class);
+ if (retval) {
+ /* something prevented us from registering this driver */
+ err("Not able to get a minor for this device.");
+ usb_set_intfdata(interface, NULL);
+ goto error;
+ }
+
+ /* let the user know what node this device is now attached to */
+ info("USB bit whaker device now attached to pic18bl-%d",
+ interface->minor);
+ return 0;
+
+error:
+ if (dev)
+ /* this frees allocated memory */
+ kref_put(&dev->kref, pic18bl_delete);
+ return retval;
+}
+
+static void pic18bl_disconnect(struct usb_interface *interface)
+{
+ struct usb_pic18bl *dev;
+ int minor = interface->minor;
+
+ dev = usb_get_intfdata(interface);
+ usb_set_intfdata(interface, NULL);
+
+ /* give back our minor */
+ usb_deregister_dev(interface, &pic18bl_class);
+
+ /* prevent more I/O from starting */
+ mutex_lock(&dev->io_mutex);
+ dev->interface = NULL;
+ mutex_unlock(&dev->io_mutex);
+
+ usb_kill_anchored_urbs(&dev->submitted);
+
+ /* decrement our usage count */
+ kref_put(&dev->kref, pic18bl_delete);
+
+ info("USB pic18bl #%d now disconnected", minor);
+}
+
+static void pic18bl_draw_down(struct usb_pic18bl *dev)
+{
+ int time;
+
+ time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
+ if (!time)
+ usb_kill_anchored_urbs(&dev->submitted);
+}
+
+static int pic18bl_suspend(struct usb_interface *intf, pm_message_t message)
+{
+ struct usb_pic18bl *dev = usb_get_intfdata(intf);
+
+ if (!dev)
+ return 0;
+ pic18bl_draw_down(dev);
+ return 0;
+}
+
+static int pic18bl_resume(struct usb_interface *intf)
+{
+ return 0;
+}
+
+static int pic18bl_pre_reset(struct usb_interface *intf)
+{
+ struct usb_pic18bl *dev = usb_get_intfdata(intf);
+
+ mutex_lock(&dev->io_mutex);
+ pic18bl_draw_down(dev);
+
+ return 0;
+}
+
+static int pic18bl_post_reset(struct usb_interface *intf)
+{
+ struct usb_pic18bl *dev = usb_get_intfdata(intf);
+
+ /* we are sure no URBs are active - no locking needed */
+ dev->errors = -EPIPE;
+ mutex_unlock(&dev->io_mutex);
+
+ return 0;
+}
+
+static struct usb_driver pic18bl_driver = {
+ .name = "pic18bl",
+ .probe = pic18bl_probe,
+ .disconnect = pic18bl_disconnect,
+ .suspend = pic18bl_suspend,
+ .resume = pic18bl_resume,
+ .pre_reset = pic18bl_pre_reset,
+ .post_reset = pic18bl_post_reset,
+ .id_table = pic18bl_table,
+ .supports_autosuspend = 0,
+};
+
+static int __init usb_pic18bl_init(void)
+{
+ int result;
+
+ /* register this driver with the USB subsystem */
+ result = usb_register(&pic18bl_driver);
+ if (result)
+ err("usb_register failed. Error number %d", result);
+
+ return result;
+}
+
+static void __exit usb_pic18bl_exit(void)
+{
+ /* deregister this driver with the USB subsystem */
+ usb_deregister(&pic18bl_driver);
+}
+
+module_init(usb_pic18bl_init);
+module_exit(usb_pic18bl_exit);
+
+MODULE_LICENSE("GPL");
Index: linux-2.6.24-rc6/MAINTAINERS
===================================================================
--- linux-2.6.24-rc6.orig/MAINTAINERS 2007-12-29 11:04:05.000000000 -0800
+++ linux-2.6.24-rc6/MAINTAINERS 2007-12-29 11:14:19.000000000 -0800
@@ -3906,6 +3906,13 @@
W: http://pegasus2.sourceforge.net/
S: Maintained
+USB PIC18 BOOT LOADER DRIVER
+P: Mark Gross
+M: [email protected]
+L: [email protected]
+W: http://www.thegnar.org/bitwhacker/bitwhacker.html
+S: Maintained
+
USB PRINTER DRIVER (usblp)
P: Pete Zaitcev
M: [email protected]
Index: linux-2.6.24-rc6/drivers/usb/misc/Kconfig
===================================================================
--- linux-2.6.24-rc6.orig/drivers/usb/misc/Kconfig 2007-12-29 11:04:05.000000000 -0800
+++ linux-2.6.24-rc6/drivers/usb/misc/Kconfig 2007-12-29 11:19:54.000000000 -0800
@@ -258,6 +258,16 @@
To compile this driver as a module, choose M here: the
module will be called iowarrior.
+config USB_PIC18_BOOTLOADER
+ tristate "PIC 18 boot load driver support"
+ depends on USB
+ help
+ Say Y here if you want to support the programming PIC18 usb
+ devices that have the Microchip boot loader firmware on them.
+
+ To compile this driver as a module, choose M here: the
+ module will be called pic18bl.
+
config USB_TEST
tristate "USB testing driver (DEVELOPMENT)"
depends on USB && USB_DEVICEFS && EXPERIMENTAL
Index: linux-2.6.24-rc6/drivers/usb/misc/Makefile
===================================================================
--- linux-2.6.24-rc6.orig/drivers/usb/misc/Makefile 2007-12-29 11:04:05.000000000 -0800
+++ linux-2.6.24-rc6/drivers/usb/misc/Makefile 2007-12-29 11:18:46.000000000 -0800
@@ -22,6 +22,7 @@
obj-$(CONFIG_USB_PHIDGETKIT) += phidgetkit.o
obj-$(CONFIG_USB_PHIDGETMOTORCONTROL) += phidgetmotorcontrol.o
obj-$(CONFIG_USB_PHIDGETSERVO) += phidgetservo.o
+obj-$(CONFIG_USB_PIC18_BOOTLOADER) += pic18bl.o
obj-$(CONFIG_USB_RIO500) += rio500.o
obj-$(CONFIG_USB_TEST) += usbtest.o
obj-$(CONFIG_USB_TRANCEVIBRATOR) += trancevibrator.o
--
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