From 35411c3fa3ca975c70357408b108e4b0d77429d4 Mon Sep 17 00:00:00 2001 From: Nick Pelly Date: Tue, 10 Aug 2010 14:46:06 -0700 Subject: [PATCH] mdm6600: Use pre-allocated, dma-coherent bulk buffer pool. The generic bulk handlers use dynamic buffer allocation. This is likely to be a performance issue. Change-Id: I9a66131d500b6152d9af118d739f3a2f3dea97c9 Signed-off-by: Nick Pelly --- drivers/usb/serial/mdm6600.c | 553 ++++++++++++++++++++++++++++++++++- 1 file changed, 542 insertions(+), 11 deletions(-) diff --git a/drivers/usb/serial/mdm6600.c b/drivers/usb/serial/mdm6600.c index c20a4137716e..6b03d86f4d04 100644 --- a/drivers/usb/serial/mdm6600.c +++ b/drivers/usb/serial/mdm6600.c @@ -1,6 +1,7 @@ /* * Copyright (C) 2010 Google, Inc. - * Re-write of Motorola's mdm6600_modem driver + * Author: Nick Pelly + * Based on Motorola's mdm6600_modem driver * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -18,16 +19,35 @@ */ /* - * TODO check suspend/resume/LP0/LP1 - * TODO remove dummy tiocmget handler + * TODO check if we need to implement throttling + * TODO handle suspend/resume/LP0/LP1 */ +#include #include #include #include +#include +#include #include +#include #include #include +#include + +static bool debug = false; +static bool debug_data = false; + +#define BP_MODEM_STATUS 0x20a1 +#define BP_RSP_AVAIL 0x01a1 +#define BP_SPEED_CHANGE 0x2aa1 + +#define BP_STATUS_CAR 0x01 +#define BP_STATUS_DSR 0x02 +#define BP_STATUS_BREAK 0x04 +#define BP_STATUS_RNG 0x08 + +#define POOL_SZ 16 #define MODEM_INTERFACE_NUM 4 @@ -37,6 +57,338 @@ static const struct usb_device_id mdm6600_id_table[] = { }; MODULE_DEVICE_TABLE(usb, mdm6600_id_table); +struct mdm6600_urb_write_pool { + spinlock_t busy_lock; /* protects busy flags */ + bool busy[POOL_SZ]; + struct urb *urb[POOL_SZ]; + struct usb_anchor in_flight; + int buffer_sz; /* allocated urb buffer size */ +}; + +struct mdm6600_urb_read_pool { + struct urb *urb[POOL_SZ]; + struct usb_anchor in_flight; /* urb's owned by USB core */ + struct work_struct work; /* bottom half */ + struct usb_anchor pending; /* urb's waiting for driver bottom half */ + int buffer_sz; /* allocated urb buffer size */ +}; + +struct mdm6600_port { + struct usb_serial *serial; + struct usb_serial_port *port; + + struct mdm6600_urb_write_pool write; + struct mdm6600_urb_read_pool read; + + u16 tiocm_status; +}; + +static void mdm6600_read_bulk_work(struct work_struct *work); +static void mdm6600_read_bulk_cb(struct urb *urb); +static void mdm6600_write_bulk_cb(struct urb *urb); + +/* called after probe for each of 5 usb_serial interfaces */ +static int mdm6600_attach(struct usb_serial *serial) +{ + int i; + struct mdm6600_port *modem; + struct usb_host_interface *host_iface = + serial->interface->cur_altsetting; + struct usb_endpoint_descriptor *epwrite = NULL; + struct usb_endpoint_descriptor *epread = NULL; + + modem = kzalloc(sizeof(*modem), GFP_KERNEL); + if (!modem) + return -ENOMEM; + usb_set_serial_data(serial, modem); + + modem->serial = serial; + modem->port = modem->serial->port[0]; /* always 1 port per usb_serial */ + modem->tiocm_status = 0; + + /* find endpoints */ + for (i = 0; i < host_iface->desc.bNumEndpoints; i++) { + struct usb_endpoint_descriptor *ep = + &host_iface->endpoint[i].desc; + if (usb_endpoint_is_bulk_out(ep)) + epwrite = ep; + if (usb_endpoint_is_bulk_in(ep)) + epread = ep; + } + if (!epwrite) { + dev_err(&serial->dev->dev, "%s No bulk out endpoint\n", + __func__); + return -EIO; + } + if (!epread) { + dev_err(&serial->dev->dev, "%s No bulk in endpoint\n", + __func__); + return -EIO; + } + + /* setup write pool */ + spin_lock_init(&modem->write.busy_lock); + init_usb_anchor(&modem->write.in_flight); + /* The * 20 calculation is from Motorola's original driver, I do not + * know the reasoning */ + modem->write.buffer_sz = le16_to_cpu(epwrite->wMaxPacketSize) * 20; + for (i = 0; i < POOL_SZ; i++) { + struct urb *u = usb_alloc_urb(0, GFP_KERNEL); + if (!u) + return -ENOMEM; + u->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; + u->transfer_buffer = usb_alloc_coherent(serial->dev, + modem->write.buffer_sz, GFP_KERNEL, &u->transfer_dma); + if (!u->transfer_buffer) + return -ENOMEM; + usb_fill_bulk_urb(u, serial->dev, + usb_sndbulkpipe(serial->dev, epwrite->bEndpointAddress), + u->transfer_buffer, modem->write.buffer_sz, + mdm6600_write_bulk_cb, modem); + modem->write.urb[i] = u; + modem->write.busy[i] = false; + } + + /* read pool */ + INIT_WORK(&modem->read.work, mdm6600_read_bulk_work); + init_usb_anchor(&modem->read.in_flight); + init_usb_anchor(&modem->read.pending); + /* The * 2 calculation is from Motorola's original driver, I do not + * know the reasoning */ + modem->read.buffer_sz = le16_to_cpu(epwrite->wMaxPacketSize) * 2; + for (i = 0; i < POOL_SZ; i++) { + struct urb *u = usb_alloc_urb(0, GFP_KERNEL); + if (!u) + return -ENOMEM; + u->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; + u->transfer_buffer = usb_alloc_coherent(serial->dev, + modem->read.buffer_sz, GFP_KERNEL, &u->transfer_dma); + if (!u->transfer_buffer) + return -ENOMEM; + usb_fill_bulk_urb(u, serial->dev, + usb_rcvbulkpipe(serial->dev, epread->bEndpointAddress), + u->transfer_buffer, modem->read.buffer_sz, + mdm6600_read_bulk_cb, modem); + modem->read.urb[i] = u; + } + + return 0; +} + +static void mdm6600_disconnect(struct usb_serial *serial) +{ + struct mdm6600_port *modem = usb_get_serial_data(serial); + + dbg("%s: port %d", __func__, modem->port->number); + + /* cancel pending writes */ + usb_kill_anchored_urbs(&modem->write.in_flight); + + /* stop reading from mdm6600 */ + usb_kill_anchored_urbs(&modem->read.in_flight); + usb_kill_urb(modem->port->interrupt_in_urb); + + /* cancel read bottom half */ + cancel_work_sync(&modem->read.work); + + /* drop pending reads */ + usb_scuttle_anchored_urbs(&modem->read.pending); + + modem->tiocm_status = 0; +} + +static void mdm6600_release_urb(struct urb *u, int sz) +{ + usb_free_coherent(u->dev, sz, u->transfer_buffer, u->transfer_dma); + u->transfer_buffer = NULL; + usb_free_urb(u); +} + +static void mdm6600_release(struct usb_serial *serial) +{ + struct mdm6600_port *modem = usb_get_serial_data(serial); + int i; + + for (i = 0; i < POOL_SZ; i++) { + mdm6600_release_urb(modem->write.urb[i], + modem->write.buffer_sz); + modem->write.urb[i] = NULL; + mdm6600_release_urb(modem->read.urb[i], modem->read.buffer_sz); + modem->read.urb[i] = NULL; + } +} + +/* called when tty is opened */ +static int mdm6600_open(struct tty_struct *tty, struct usb_serial_port *port) +{ + int i; + int rc = 0; + struct mdm6600_port *modem = usb_get_serial_data(port->serial); + + dbg("%s: port %d", __func__, port->number); + + BUG_ON(modem->port != port); + + modem->tiocm_status = 0; + + if (port->number == MODEM_INTERFACE_NUM) { + BUG_ON(!port->interrupt_in_urb); + rc = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); + if (rc) { + dev_err(&port->dev, + "%s: failed to submit interrupt urb, error %d\n", + __func__, rc); + return rc; + } + } + for (i = 0; i < POOL_SZ; i++) { + rc = usb_submit_urb(modem->read.urb[i], GFP_KERNEL); + if (rc) { + dev_err(&port->dev, + "%s: failed to submit bulk read urb, error %d\n", + __func__, rc); + return rc; + } + } + + return rc; +} + +static void mdm6600_close(struct usb_serial_port *port) +{ + struct mdm6600_port *modem = usb_get_serial_data(port->serial); + + dbg("%s: port %d", __func__, port->number); + + /* cancel pending writes */ + usb_kill_anchored_urbs(&modem->write.in_flight); + + /* stop reading from mdm6600 */ + usb_kill_anchored_urbs(&modem->read.in_flight); + usb_kill_urb(port->interrupt_in_urb); + + /* cancel read bottom half */ + cancel_work_sync(&modem->read.work); + + /* drop pending reads */ + usb_scuttle_anchored_urbs(&modem->read.pending); + + modem->tiocm_status = 0; +} + +static struct urb *mdm6600_get_unused_write_urb( + struct mdm6600_urb_write_pool *p) +{ + int i; + unsigned long flags; + struct urb *u = NULL; + + spin_lock_irqsave(&p->busy_lock, flags); + + for (i = 0; i < POOL_SZ; i++) + if (!p->busy[i]) + break; + if (i >= POOL_SZ) + goto out; + + u = p->urb[i]; + p->busy[i] = true; + +out: + spin_unlock_irqrestore(&p->busy_lock, flags); + return u; +} + +static int mdm6600_mark_write_urb_unused(struct mdm6600_urb_write_pool *p, + struct urb *u) +{ + int i; + unsigned long flags; + int rc = -EINVAL; + + spin_lock_irqsave(&p->busy_lock, flags); + + for (i = 0; i < POOL_SZ; i++) + if (p->urb[i] == u) + break; + if (i >= POOL_SZ) + goto out; + + p->busy[i] = false; + rc = 0; + +out: + spin_unlock_irqrestore(&p->busy_lock, flags); + return rc; +} + +static void mdm6600_write_bulk_cb(struct urb *u) +{ + int status; + struct mdm6600_port *modem = u->context; + + dbg("%s: urb %p status %d", __func__, u, u->status); + + status = u->status; + if (status) + dev_warn(&modem->serial->dev->dev, "%s non-zero status %d\n", + __func__, u->status); + + if (mdm6600_mark_write_urb_unused(&modem->write, u)) + dev_warn(&modem->serial->dev->dev, "%s unknown urb %p\n", + __func__, u); + + if (!status) + usb_serial_port_softint(modem->port); +} + +static int mdm6600_write(struct tty_struct *tty, struct usb_serial_port *port, + const unsigned char *buf, int count) +{ + int rc; + struct urb *u; + struct usb_serial *serial = port->serial; + struct mdm6600_port *modem = usb_get_serial_data(port->serial); + + dbg("%s: port %d count %d pool %p", __func__, port->number, count, + &modem->write); + + if (!count || !serial->num_bulk_out) + return 0; + + u = mdm6600_get_unused_write_urb(&modem->write); + if (!u) { + dev_info(&port->dev, "%s: all buffers busy!\n", __func__); + return 0; + } + + count = min(count, modem->write.buffer_sz); + memcpy(u->transfer_buffer, buf, count); + u->transfer_buffer_length = count; + usb_serial_debug_data(debug_data, &port->dev, __func__, + u->transfer_buffer_length, u->transfer_buffer); + + rc = usb_submit_urb(u, GFP_ATOMIC); + if (rc < 0) { + dev_err(&port->dev, "%s: submit bulk urb failed %d\n", + __func__, rc); + return rc; + } + + return count; +} + +static int mdm6600_tiocmget(struct tty_struct *tty, struct file *file) +{ + struct usb_serial_port *port = tty->driver_data; + struct mdm6600_port *modem = usb_get_serial_data(port->serial); + + dbg("%s: port %d modem_status %x\n", __func__, port->number, + modem->tiocm_status); + + return modem->tiocm_status; +} + static int mdm6600_dtr_control(struct usb_serial_port *port, int ctrl) { struct usb_device *dev = port->serial->dev; @@ -61,17 +413,14 @@ static int mdm6600_dtr_control(struct usb_serial_port *port, int ctrl) return rc; } -static int mdm6600_tiocmget(struct tty_struct *tty, struct file *file) -{ - /* testing if this ever really gets called */ - BUG_ON(1); -} - static int mdm6600_tiocmset(struct tty_struct *tty, struct file *file, - unsigned int set, unsigned int clear) + unsigned int set, unsigned int clear) { struct usb_serial_port *port = tty->driver_data; + dbg("%s: port %d set %x clear %x\n", __func__, port->number, set, + clear); + if (port->number != MODEM_INTERFACE_NUM) return 0; if (clear & TIOCM_DTR) @@ -81,6 +430,176 @@ static int mdm6600_tiocmset(struct tty_struct *tty, struct file *file, return 0; } +static void mdm6600_apply_bp_status(u8 bp_status, u16 *tiocm_status) +{ + if (bp_status & BP_STATUS_CAR) + *tiocm_status |= TIOCM_CAR; + else + *tiocm_status &= ~TIOCM_CAR; + if (bp_status & BP_STATUS_DSR) + *tiocm_status |= TIOCM_DSR; + else + *tiocm_status &= ~TIOCM_DSR; + if (bp_status & BP_STATUS_RNG) + *tiocm_status |= TIOCM_RNG; + else + *tiocm_status &= ~TIOCM_RNG; +} + +static void mdm6600_read_int_callback(struct urb *u) +{ + int rc; + u16 request; + u8 *data = u->transfer_buffer; + struct usb_serial_port *port = u->context; + struct mdm6600_port *modem = usb_get_serial_data(port->serial); + + dbg("%s: urb %p", __func__, u); + + switch (u->status) { + case 0: + /* success */ + break; + case -ECONNRESET: + case -ENOENT: + case -ESHUTDOWN: + dbg("%s: urb terminated, status %d", __func__, u->status); + goto exit; + default: + dbg("%s: urb status non-zero %d", __func__, u->status); + goto exit; + } + + usb_serial_debug_data(debug_data, &port->dev, __func__, + u->actual_length, data); + + if (u->actual_length < 2) { + dbg("%s: interrupt transfer too small %d", + __func__, u->actual_length); + goto exit; + } + request = *((u16 *)data); + + switch (request) { + case BP_MODEM_STATUS: + if (u->actual_length < 9) { + dev_err(&port->dev, + "%s: modem status urb too small %d\n", + __func__, u->actual_length); + break; + } + if (port->number != MODEM_INTERFACE_NUM) + break; + mdm6600_apply_bp_status(data[8], &modem->tiocm_status); + dbg("%s: modem_status now %x", __func__, modem->tiocm_status); + break; + case BP_RSP_AVAIL: + dbg("%s: BP_RSP_AVAIL", __func__); + break; + case BP_SPEED_CHANGE: + dbg("%s: BP_SPEED_CHANGE", __func__); + break; + default: + dbg("%s: undefined BP request type %d", __func__, request); + break; + } + +exit: + rc = usb_submit_urb(u, GFP_ATOMIC); + if (rc) + dev_err(&u->dev->dev, + "%s: Error %d re-submitting interrupt urb\n", + __func__, rc); +} + +static size_t mdm6600_pass_to_tty(struct tty_struct *tty, void *buf, size_t sz) +{ + unsigned char *b = buf; + size_t c; + size_t s = sz; + + tty_buffer_request_room(tty, sz); + while (s > 0) { + c = tty_insert_flip_string(tty, b, s); + if (c != s) + dbg("%s passed only %u of %u bytes\n", + __func__, c, s); + if (c == 0) + break; + tty_flip_buffer_push(tty); + s -= c; + b += c; + } + + return sz - s; +} + +static void mdm6600_read_bulk_work(struct work_struct *work) +{ + int rc; + size_t c; + struct urb *u; + struct tty_struct *tty; + struct mdm6600_port *modem = container_of(work, struct mdm6600_port, + read.work); + + dbg("%s", __func__); + + while (true) { + u = usb_get_from_anchor(&modem->read.pending); + if (!u) + break; + dbg("%s: processing urb %p len %u", __func__, u, + u->actual_length); + usb_serial_debug_data(debug_data, &modem->port->dev, __func__, + u->actual_length, u->transfer_buffer); + tty = tty_port_tty_get(&modem->port->port); + if (!tty) { + dev_warn(&modem->port->dev, "%s: could not find tty\n", + __func__); + goto next; + } + c = mdm6600_pass_to_tty(tty, u->transfer_buffer, + u->actual_length); + if (c != u->actual_length) + dev_warn(&modem->port->dev, + "%s: dropped %u of %u bytes\n", + __func__, u->actual_length - c, + u->actual_length); + tty_kref_put(tty); + +next: + rc = usb_submit_urb(u, GFP_KERNEL); + if (rc) + dev_err(&u->dev->dev, + "%s: Error %d re-submitting read urb\n", + __func__, rc); + } +} + +static void mdm6600_read_bulk_cb(struct urb *u) +{ + struct mdm6600_port *modem = u->context; + + dbg("%s: urb %p", __func__, u); + + if (u->status) { + int rc; + dev_warn(&modem->serial->dev->dev, "%s non-zero status %d\n", + __func__, u->status); + /* straight back into use */ + rc = usb_submit_urb(u, GFP_ATOMIC); + if (rc) + dev_err(&u->dev->dev, + "%s: Error %d re-submitting read urb\n", + __func__, rc); + return; + } + + usb_anchor_urb(u, &modem->read.pending); + schedule_work(&modem->read.work); +} + static struct usb_driver mdm6600_usb_driver = { .name = "mdm6600", .probe = usb_serial_probe, @@ -94,12 +613,19 @@ static struct usb_serial_driver mdm6600_usb_serial_driver = { .owner = THIS_MODULE, .name = "mdm6600", }, + .num_ports = 1, .description = "MDM 6600 modem usb-serial driver", .id_table = mdm6600_id_table, - .num_ports = 1, /* TODO: confirm this number is useless */ .usb_driver = &mdm6600_usb_driver, + .attach = mdm6600_attach, + .disconnect = mdm6600_disconnect, + .release = mdm6600_release, + .open = mdm6600_open, + .close = mdm6600_close, + .write = mdm6600_write, .tiocmset = mdm6600_tiocmset, .tiocmget = mdm6600_tiocmget, + .read_int_callback = mdm6600_read_int_callback, }; static int __init mdm6600_init(void) @@ -124,3 +650,8 @@ static void __exit mdm6600_exit(void) module_init(mdm6600_init); module_exit(mdm6600_exit); MODULE_LICENSE("GPL"); + +module_param(debug, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(debug, "Debug enabled or not"); +module_param(debug_data, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(debug_data, "Debug enabled or not"); -- 2.34.1