Return-Path: Sender: "Gustavo F. Padovan" Date: Thu, 7 Oct 2010 15:45:34 -0300 From: "Gustavo F. Padovan" To: pavan_savoy@ti.com Cc: linux-bluetooth@vger.kernel.org, marcel@holtmann.org, greg@kroah.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] drivers:bluetooth: TI_ST bluetooth driver Message-ID: <20101007184534.GB13602@vigoh> References: <1286477237-7526-1-git-send-email-pavan_savoy@ti.com> <1286477237-7526-2-git-send-email-pavan_savoy@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1286477237-7526-2-git-send-email-pavan_savoy@ti.com> List-ID: Hi Pavan, Change the commit subject to "Bluetooth: TI_ST bluetooth driver" * pavan_savoy@ti.com [2010-10-07 14:47:16 -0400]: > From: Pavan Savoy > > 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. > > Signed-off-by: Pavan Savoy > --- > drivers/bluetooth/bt_ti.c | 489 +++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 489 insertions(+), 0 deletions(-) > create mode 100644 drivers/bluetooth/bt_ti.c We don't have filename with bt_.. in drivers/bluetooth/. Maybe ti_st.c should be a better name, or something like that. > > diff --git a/drivers/bluetooth/bt_ti.c b/drivers/bluetooth/bt_ti.c > new file mode 100644 > index 0000000..dffbb56 > --- /dev/null > +++ b/drivers/bluetooth/bt_ti.c > @@ -0,0 +1,489 @@ > +/* > + * 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 > + * Pavan Savoy > + * > + * 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 > +#include > +#include > + > +#include > + > +/* Bluetooth Driver Version */ > +#define VERSION "1.0" > + > +/* Defines number of seconds to wait for reg completion > + * callback getting called from ST (in case,registration > + * with ST returns PENDING status) > + */ > +#define BT_REGISTER_TIMEOUT 6000 /* 6 sec */ > + > +/* BT driver's local status */ > +#define BT_DRV_RUNNING 0 > +#define BT_ST_REGISTERED 1 > + > +/** > + * struct hci_st - BT driver operation structure > + * @hdev: hci device pointer which binds to bt driver > + * @flags: used locally,to maintain various BT driver status > + * @streg_cbdata: to hold ST registration callback status > + * @st_write: write function pointer of ST driver > + * @wait_for_btdrv_reg_completion - completion sync between hci_st_open > + * and hci_st_registration_completion_cb. > + */ > +struct hci_st { > + struct hci_dev *hdev; > + unsigned long flags; > + char streg_cbdata; > + long (*st_write) (struct sk_buff *); > + struct completion wait_for_btdrv_reg_completion; > +}; > + > +static int reset; > + > +/* Increments HCI counters based on pocket ID (cmd,acl,sco) */ > +static inline void hci_st_tx_complete(struct hci_st *hst, int pkt_type) > +{ > + struct hci_dev *hdev; > + 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.cmd_tx++; it should be sco_tx here. > + break; > + } > +} > + > +/* ------- Interfaces to Shared Transport ------ */ > + > +/* Called by ST layer to indicate protocol registration completion > + * status.hci_st_open() function will wait for signal from this > + * API when st_register() function returns ST_PENDING. > + */ > +static void hci_st_registration_completion_cb(void *priv_data, char data) That is not the hci layer, so rename this function (and the others) to something that reflect where they are really doing. > +{ > + struct hci_st *lhst = (struct hci_st *)priv_data; > + /* hci_st_open() function needs value of 'data' to know > + * the registration status(success/fail),So have a back > + * up of it. > + */ > + lhst->streg_cbdata = data; > + > + /* Got a feedback from ST for BT driver registration > + * request.Wackup hci_st_open() function to continue > + * it's open operation. > + */ > + complete(&lhst->wait_for_btdrv_reg_completion); > +} > + > +/* Called by Shared Transport layer when receive data is > + * available */ > +static long hci_st_receive(void *priv_data, struct sk_buff *skb) > +{ > + int err; > + int len; you can put err and len in the same line. > + struct hci_st *lhst = (struct hci_st *)priv_data; > + > + err = 0; > + len = 0; and no need to set them to 0 here. > + > + if (skb == NULL) { > + BT_ERR("Invalid SKB received from ST"); > + return -EFAULT; > + } We need a empty line here. > + if (!lhst) { > + kfree_skb(skb); > + BT_ERR("Invalid hci_st memory,freeing SKB"); > + return -EFAULT; > + } And also here. Check the rest of the code for similar issues. > + if (!test_bit(BT_DRV_RUNNING, &lhst->flags)) { > + kfree_skb(skb); > + BT_ERR("Device is not running,freeing SKB"); > + return -EINVAL; > + } If you are here, your device is running, right? Or am I missing something? > + > + len = skb->len; > + skb->dev = (struct net_device *)lhst->hdev; > + > + /* Forward skb to HCI CORE layer */ > + err = hci_recv_frame(skb); > + if (err) { > + kfree_skb(skb); > + BT_ERR("Unable to push skb to HCI CORE(%d),freeing SKB", > + err); > + return err; > + } > + lhst->hdev->stat.byte_rx += len; actually you even don't need len, just use skb->len > + > + return 0; > +} > + > +/* ------- Interfaces to HCI layer ------ */ > + > +/* Called from HCI core to initialize the device */ > +static int hci_st_open(struct hci_dev *hdev) > +{ > + static struct st_proto_s hci_st_proto; > + unsigned long timeleft; > + struct hci_st *hst; > + int err; > + err = 0; > + > + BT_DBG("%s %p", hdev->name, hdev); > + hst = hdev->driver_data; > + > + /* Populate BT driver info required by ST */ > + memset(&hci_st_proto, 0, sizeof(hci_st_proto)); > + > + /* BT driver ID */ > + hci_st_proto.type = ST_BT; > + > + /* Receive function which called from ST */ > + hci_st_proto.recv = hci_st_receive; > + > + /* Packet match function may used in future */ > + hci_st_proto.match_packet = NULL; It is already NULL, you dua a memset. > + > + /* Callback to be called when registration is pending */ > + hci_st_proto.reg_complete_cb = hci_st_registration_completion_cb; > + > + /* This is write function pointer of ST. BT driver will make use of this > + * for sending any packets to chip. ST will assign and give to us, so > + * make it as NULL */ > + hci_st_proto.write = NULL; Same here. > + > + /* send in the hst to be received at registration complete callback > + * and during st's receive > + */ > + hci_st_proto.priv_data = hst; > + > + /* Register with ST layer */ > + err = st_register(&hci_st_proto); > + if (err == -EINPROGRESS) { > + /* Prepare wait-for-completion handler data structures. > + * Needed to syncronize this and st_registration_completion_cb() > + * functions. > + */ > + init_completion(&hst->wait_for_btdrv_reg_completion); I'm not liking that, but I'll leave for Marcel and others comment. > + > + /* Reset ST registration callback status flag , this value > + * will be updated in hci_st_registration_completion_cb() > + * function whenever it called from ST driver. > + */ > + hst->streg_cbdata = -EINPROGRESS; > + > + /* ST is busy with other protocol registration(may be busy with > + * firmware download).So,Wait till the registration callback > + * (passed as a argument to st_register() function) getting > + * called from ST. > + */ > + BT_DBG(" %s waiting for reg completion signal from ST", > + __func__); > + > + timeleft = > + wait_for_completion_timeout > + (&hst->wait_for_btdrv_reg_completion, > + msecs_to_jiffies(BT_REGISTER_TIMEOUT)); > + if (!timeleft) { > + 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 value? */ > + if (hst->streg_cbdata != 0) { > + BT_ERR("ST reg completion CB called with invalid" > + "status %d", hst->streg_cbdata); > + return -EAGAIN; > + } > + err = 0; > + } else if (err == -1) { Use the proper error macro instead "-1" > + BT_ERR("st_register failed %d", err); > + return -EAGAIN; > + } > + > + /* Do we have proper ST write function? */ > + if (hci_st_proto.write != NULL) { > + /* We need this pointer for sending any Bluetooth pkts */ > + hst->st_write = hci_st_proto.write; > + } else { > + BT_ERR("failed to get ST write func pointer"); > + > + /* Undo registration with ST */ > + err = st_unregister(ST_BT); > + if (err < 0) > + BT_ERR("st_unregister failed %d", err); > + > + hst->st_write = NULL; > + return -EAGAIN; > + } > + > + /* Registration with ST layer is completed successfully, > + * now chip is ready to accept commands from HCI CORE. > + * Mark HCI Device flag as RUNNING > + */ > + set_bit(HCI_RUNNING, &hdev->flags); > + > + /* Registration with ST successful */ > + set_bit(BT_ST_REGISTERED, &hst->flags); > + > + return err; > +} > + > +/* Close device */ > +static int hci_st_close(struct hci_dev *hdev) > +{ > + int err; > + struct hci_st *hst; Skip a line after declarations. > + err = 0; you can set err to 0 in the declaration if you really need that. > + > + hst = hdev->driver_data; > + /* Unregister from ST layer */ > + if (test_and_clear_bit(BT_ST_REGISTERED, &hst->flags)) { > + err = st_unregister(ST_BT); > + if (err != 0) { > + BT_ERR("st_unregister failed %d", err); > + return -EBUSY; > + } > + } > + > + hst->st_write = NULL; > + > + /* ST layer would have moved chip to inactive state. > + * So,clear HCI device RUNNING flag. > + */ > + if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags)) > + return 0; Looks you are screwing up the flags here, if it fails on st_unregister() and returns HCI_RUNNING should keep set? > + > + return err; Rethink how you are doing error handling here, it should no be complicated like that. > +} > + > +/* Called from HCI CORE , Sends frames to Shared Transport */ > +static int hci_st_send_frame(struct sk_buff *skb) > +{ > + struct hci_dev *hdev; > + struct hci_st *hst; > + long len; > + > + if (skb == NULL) { > + BT_ERR("Invalid skb received from HCI CORE"); > + return -ENOMEM; > + } > + hdev = (struct hci_dev *)skb->dev; > + if (!hdev) { > + BT_ERR("SKB received for invalid HCI Device (hdev=NULL)"); > + return -ENODEV; > + } > + if (!test_bit(HCI_RUNNING, &hdev->flags)) { > + BT_ERR("Device is not running"); > + return -EBUSY; > + } > + > + hst = (struct hci_st *)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. > + */ > + if (!hst->st_write) { > + kfree_skb(skb); > + BT_ERR(" Can't write to ST, st_write null?"); > + return -EAGAIN; > + } > + len = hst->st_write(skb); > + if (len < 0) { > + /* Something went wrong in st write , free skb memory */ IMHO we don't need comments like that, clearly we now that something went wrong. > + kfree_skb(skb); > + BT_ERR(" ST write failed (%ld)", len); > + return -EAGAIN; > + } > + > + /* ST accepted our skb. So, Go ahead and do rest */ > + hdev->stat.byte_tx += len; > + hci_st_tx_complete(hst, bt_cb(skb)->pkt_type); > + > + return 0; goto might be better to handle error here. -- Gustavo F. Padovan ProFUSION embedded systems - http://profusion.mobi