Messages in this thread | | | Date | Tue, 30 Nov 2010 12:59:52 +0530 | Subject | Re: [PATCH v7] Bluetooth: btwilink driver | From | Pavan Savoy <> |
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On Fri, Nov 26, 2010 at 2:50 PM, <pavan_savoy@ti.com> wrote: > From: Pavan Savoy <pavan_savoy@ti.com> > Marcel, Gustavo,
Please find some time to comment and also answer some of the concerns I have below,
Thanks & Regards, Pavan Savoy.
> comments attended to from v5 and v6, > > 1. Inside ti_st_open, I previously only checked for EINPROGRESS & EPERM, > Now I handle for EINPROGRESS - which is not really an error and > return during all other error cases. > > 2. _write is still a function pointer and not an exported function, I > need to change the underlying driver's code for this. > However, previous lkml comments on the underlying driver's code > suggested it to be kept as a function pointer and not EXPORT. > Gustavo, Marcel - Please comment on this. > Is this absolutely required? If so why? > > 3. test_and_set_bit of HCI_RUNNING is done at beginning of > ti_st_open, and did not see issues during firmware download. > However ideally I would still like to set HCI_RUNNING once the firmware > download is done, because I don't want to allow a _send_frame during > firmware download - Marcel, Gustavo - Please comment. > > 4. test_and_clear of HCI_RUNNING now done @ beginning of close. > > 5. EAGAIN on failure of st_write is to suggest to try and write again. > I have never this happen - However only if UART goes bad this case may > occur. > > 6. ti_st_tx_complete is very similar to hci_ldisc's tx_complete - in > fact the code is pretty much borrowed from there. > Marcel, Gustavo - Please suggest where should it be done? If not here. > > 7. comments cleaned-up + hst memory leak fixed when hci_alloc_dev fails. > > 8. platform_driver registration inside module_init now is similar to > other drivers. > > 9. Dan Carpenter's comments on leaking hst memory on failed > hci_register_dev and empty space after quotes in debug statements > fixed. > > Thanks for the comments... > Sorry, for previously not being very clear on which comments were > handled and which were not. > > -- patch description -- > > This is the bluetooth protocol driver for the TI WiLink7 chipsets. > Texas Instrument's WiLink chipsets combine wireless technologies > like BT, FM, GPS and WLAN onto a single chip. > > This Bluetooth driver works on top of the TI_ST shared transport > line discipline driver which also allows other drivers like > FM V4L2 and GPS character driver to make use of the same UART interface. > > Kconfig and Makefile modifications to enable the Bluetooth > driver for Texas Instrument's WiLink 7 chipset. > > Signed-off-by: Pavan Savoy <pavan_savoy@ti.com> > --- > drivers/bluetooth/Kconfig | 10 ++ > drivers/bluetooth/Makefile | 1 + > drivers/bluetooth/btwilink.c | 363 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 374 insertions(+), 0 deletions(-) > create mode 100644 drivers/bluetooth/btwilink.c > > diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig > index 02deef4..8e0de9a 100644 > --- a/drivers/bluetooth/Kconfig > +++ b/drivers/bluetooth/Kconfig > @@ -219,4 +219,14 @@ config BT_ATH3K > Say Y here to compile support for "Atheros firmware download driver" > into the kernel or say M to compile it as module (ath3k). > > +config BT_WILINK > + tristate "Texas Instruments WiLink7 driver" > + depends on TI_ST > + help > + This enables the Bluetooth driver for Texas Instrument's BT/FM/GPS > + combo devices. This makes use of shared transport line discipline > + core driver to communicate with the BT core of the combo chip. > + > + Say Y here to compile support for Texas Instrument's WiLink7 driver > + into the kernel or say M to compile it as module. > endmenu > diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile > index 71bdf13..f4460f4 100644 > --- a/drivers/bluetooth/Makefile > +++ b/drivers/bluetooth/Makefile > @@ -18,6 +18,7 @@ obj-$(CONFIG_BT_HCIBTSDIO) += btsdio.o > obj-$(CONFIG_BT_ATH3K) += ath3k.o > obj-$(CONFIG_BT_MRVL) += btmrvl.o > obj-$(CONFIG_BT_MRVL_SDIO) += btmrvl_sdio.o > +obj-$(CONFIG_BT_WILINK) += btwilink.o > > btmrvl-y := btmrvl_main.o > btmrvl-$(CONFIG_DEBUG_FS) += btmrvl_debugfs.o > diff --git a/drivers/bluetooth/btwilink.c b/drivers/bluetooth/btwilink.c > new file mode 100644 > index 0000000..71e69f8 > --- /dev/null > +++ b/drivers/bluetooth/btwilink.c > @@ -0,0 +1,363 @@ > +/* > + * Texas Instrument's Bluetooth Driver For Shared Transport. > + * > + * Bluetooth Driver acts as interface between HCI core and > + * TI Shared Transport Layer. > + * > + * Copyright (C) 2009-2010 Texas Instruments > + * Author: Raja Mani <raja_mani@ti.com> > + * Pavan Savoy <pavan_savoy@ti.com> > + * > + * 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 > + * published by the Free Software Foundation. > + * > + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA > + * > + */ > + > +#include <linux/platform_device.h> > +#include <net/bluetooth/bluetooth.h> > +#include <net/bluetooth/hci_core.h> > + > +#include <linux/ti_wilink_st.h> > + > +/* Bluetooth Driver Version */ > +#define VERSION "1.0" > + > +/* Number of seconds to wait for registration completion > + * when ST returns PENDING status. > + */ > +#define BT_REGISTER_TIMEOUT 6000 /* 6 sec */ > + > +/** > + * struct ti_st - driver operation structure > + * @hdev: hci device pointer which binds to bt driver > + * @reg_status: ST registration callback status > + * @st_write: write function provided by the ST driver > + * to be used by the driver during send_frame. > + * @wait_reg_completion - completion sync between ti_st_open > + * and ti_st_registration_completion_cb. > + */ > +struct ti_st { > + struct hci_dev *hdev; > + char reg_status; > + long (*st_write) (struct sk_buff *); > + struct completion wait_reg_completion; > +}; > + > +/* Increments HCI counters based on pocket ID (cmd,acl,sco) */ > +static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type) > +{ > + struct hci_dev *hdev = hst->hdev; > + > + /* Update HCI stat counters */ > + switch (pkt_type) { > + case HCI_COMMAND_PKT: > + hdev->stat.cmd_tx++; > + break; > + > + case HCI_ACLDATA_PKT: > + hdev->stat.acl_tx++; > + break; > + > + case HCI_SCODATA_PKT: > + hdev->stat.sco_tx++; > + break; > + } > +} > + > +/* ------- Interfaces to Shared Transport ------ */ > + > +/* Called by ST layer to indicate protocol registration completion > + * status.ti_st_open() function will wait for signal from this > + * API when st_register() function returns ST_PENDING. > + */ > +static void st_registration_completion_cb(void *priv_data, char data) > +{ > + struct ti_st *lhst = priv_data; > + > + /* Save registration status for use in ti_st_open() */ > + lhst->reg_status = data; > + /* complete the wait in ti_st_open() */ > + complete(&lhst->wait_reg_completion); > +} > + > +/* Called by Shared Transport layer when receive data is > + * available */ > +static long st_receive(void *priv_data, struct sk_buff *skb) > +{ > + struct ti_st *lhst = priv_data; > + int err; > + > + if (!skb) > + return -EFAULT; > + > + if (!lhst) { > + kfree_skb(skb); > + return -EFAULT; > + } > + > + skb->dev = (void *) lhst->hdev; > + > + /* Forward skb to HCI core layer */ > + err = hci_recv_frame(skb); > + if (err < 0) { > + BT_ERR("Unable to push skb to HCI core(%d)", err); > + return err; > + } > + > + lhst->hdev->stat.byte_rx += skb->len; > + > + return 0; > +} > + > +/* ------- Interfaces to HCI layer ------ */ > +/* protocol structure registered with shared transport */ > +static struct st_proto_s ti_st_proto = { > + .type = ST_BT, > + .recv = st_receive, > + .reg_complete_cb = st_registration_completion_cb, > +}; > + > +/* Called from HCI core to initialize the device */ > +static int ti_st_open(struct hci_dev *hdev) > +{ > + unsigned long timeleft; > + struct ti_st *hst; > + int err; > + > + BT_DBG("%s %p", hdev->name, hdev); > + if (test_and_set_bit(HCI_RUNNING, &hdev->flags)) { > + BT_ERR("btwilink already opened"); > + return -EBUSY; > + } > + > + /* provide contexts for callbacks from ST */ > + hst = hdev->driver_data; > + ti_st_proto.priv_data = hst; > + > + err = st_register(&ti_st_proto); > + if (err == -EINPROGRESS) { > + /* ST is busy with either protocol registration or firmware > + * download. > + */ > + /* Prepare wait-for-completion handler data structures. > + */ > + init_completion(&hst->wait_reg_completion); > + > + /* Reset ST registration callback status flag , this value > + * will be updated in ti_st_registration_completion_cb() > + * function whenever it called from ST driver. > + */ > + hst->reg_status = -EINPROGRESS; > + > + BT_DBG("waiting for registration completion signal from ST"); > + timeleft = wait_for_completion_timeout > + (&hst->wait_reg_completion, > + msecs_to_jiffies(BT_REGISTER_TIMEOUT)); > + if (!timeleft) { > + clear_bit(HCI_RUNNING, &hdev->flags); > + BT_ERR("Timeout(%d sec),didn't get reg " > + "completion signal from ST", > + BT_REGISTER_TIMEOUT / 1000); > + return -ETIMEDOUT; > + } > + > + /* Is ST registration callback called with ERROR status? */ > + if (hst->reg_status != 0) { > + clear_bit(HCI_RUNNING, &hdev->flags); > + BT_ERR("ST registration completed with invalid " > + "status %d", hst->reg_status); > + return -EAGAIN; > + } > + err = 0; > + } else if (err != 0) { > + clear_bit(HCI_RUNNING, &hdev->flags); > + BT_ERR("st_register failed %d", err); > + return err; > + } > + > + /* ti_st_proto.write is filled up by the underlying shared > + * transport driver upon registration > + */ > + hst->st_write = ti_st_proto.write; > + if (!hst->st_write) { > + BT_ERR("undefined ST write function"); > + clear_bit(HCI_RUNNING, &hdev->flags); > + > + /* Undo registration with ST */ > + err = st_unregister(ST_BT); > + if (err) > + BT_ERR("st_unregister() failed with error %d", err); > + > + hst->st_write = NULL; > + return err; > + } > + > + return err; > +} > + > +/* Close device */ > +static int ti_st_close(struct hci_dev *hdev) > +{ > + int err; > + struct ti_st *hst = hdev->driver_data; > + > + if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags)) > + return 0; > + > + /* continue to unregister from transport */ > + err = st_unregister(ST_BT); > + if (err) > + BT_ERR("st_unregister() failed with error %d", err); > + > + hst->st_write = NULL; > + > + return err; > +} > + > +static int ti_st_send_frame(struct sk_buff *skb) > +{ > + struct hci_dev *hdev; > + struct ti_st *hst; > + long len; > + > + hdev = (struct hci_dev *)skb->dev; > + > + if (!test_bit(HCI_RUNNING, &hdev->flags)) > + return -EBUSY; > + > + hst = hdev->driver_data; > + > + /* Prepend skb with frame type */ > + memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1); > + > + BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, > + skb->len); > + > + /* Insert skb to shared transport layer's transmit queue. > + * Freeing skb memory is taken care in shared transport layer, > + * so don't free skb memory here. > + */ > + len = hst->st_write(skb); > + if (len < 0) { > + kfree_skb(skb); > + BT_ERR("ST write failed (%ld)", len); > + /* Try Again, would only fail if UART has gone bad */ > + return -EAGAIN; > + } > + > + /* ST accepted our skb. So, Go ahead and do rest */ > + hdev->stat.byte_tx += len; > + ti_st_tx_complete(hst, bt_cb(skb)->pkt_type); > + > + return 0; > +} > + > +static void ti_st_destruct(struct hci_dev *hdev) > +{ > + BT_DBG("%s", hdev->name); > + kfree(hdev->driver_data); > +} > + > +static int bt_ti_probe(struct platform_device *pdev) > +{ > + static struct ti_st *hst; > + struct hci_dev *hdev; > + int err; > + > + hst = kzalloc(sizeof(struct ti_st), GFP_KERNEL); > + if (!hst) > + return -ENOMEM; > + > + /* Expose "hciX" device to user space */ > + hdev = hci_alloc_dev(); > + if (!hdev) { > + kfree(hst); > + return -ENOMEM; > + } > + > + BT_DBG("hdev %p", hdev); > + > + hst->hdev = hdev; > + hdev->bus = HCI_UART; > + hdev->driver_data = hst; > + hdev->open = ti_st_open; > + hdev->close = ti_st_close; > + hdev->flush = NULL; > + hdev->send = ti_st_send_frame; > + hdev->destruct = ti_st_destruct; > + hdev->owner = THIS_MODULE; > + > + err = hci_register_dev(hdev); > + if (err < 0) { > + BT_ERR("Can't register HCI device error %d", err); > + kfree(hst); > + hci_free_dev(hdev); > + return err; > + } > + > + BT_DBG("HCI device registered (hdev %p)", hdev); > + > + dev_set_drvdata(&pdev->dev, hst); > + return err; > +} > + > +static int bt_ti_remove(struct platform_device *pdev) > +{ > + struct hci_dev *hdev; > + struct ti_st *hst = dev_get_drvdata(&pdev->dev); > + > + if (!hst) > + return -EFAULT; > + > + hdev = hst->hdev; > + ti_st_close(hdev); > + hci_unregister_dev(hdev); > + > + hci_free_dev(hdev); > + kfree(hst); > + > + dev_set_drvdata(&pdev->dev, NULL); > + return 0; > +} > + > +static struct platform_driver btwilink_driver = { > + .probe = bt_ti_probe, > + .remove = bt_ti_remove, > + .driver = { > + .name = "btwilink", > + .owner = THIS_MODULE, > + }, > +}; > + > +/* ------- Module Init/Exit interfaces ------ */ > +static int __init btwilink_init(void) > +{ > + BT_INFO("Bluetooth Driver for TI WiLink - Version %s", VERSION); > + > + return platform_driver_register(&btwilink_driver); > +} > + > +static void __exit btwilink_exit(void) > +{ > + platform_driver_unregister(&btwilink_driver); > +} > + > +module_init(btwilink_init); > +module_exit(btwilink_exit); > + > +/* ------ Module Info ------ */ > + > +MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>"); > +MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION); > +MODULE_VERSION(VERSION); > +MODULE_LICENSE("GPL"); > -- > 1.5.6.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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