Return-Path: Sender: "Gustavo F. Padovan" Date: Thu, 14 Oct 2010 10:31:18 -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] Bluetooth: TI_ST bluetooth driver Message-ID: <20101014133118.GC9250@vigoh> References: <1286814803-6740-1-git-send-email-pavan_savoy@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1286814803-6740-1-git-send-email-pavan_savoy@ti.com> List-ID: Hi Pavan, * pavan_savoy@ti.com [2010-10-11 12:33:23 -0400]: > From: Pavan Savoy > > Gustavo, Marcel, > > I have taken care of most of the comments which you provided. > Couple of them like usage of goto's, I didn't handle since > I am not doing much error handling repeatedly there. > > I have also removed the 2 states like _REGISTERED, _RUNNING which > were not required and the flags associated with it. > I have taken care of other style comments. > > Please review and provide your comments, > > -- 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 > --- > drivers/bluetooth/Kconfig | 10 + > drivers/bluetooth/Makefile | 1 + > drivers/bluetooth/btwilink.c | 455 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 466 insertions(+), 0 deletions(-) > create mode 100644 drivers/bluetooth/btwilink.c > > diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig > index 02deef4..e0d67dd 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 "BlueZ bluetooth driver for TI ST" > + 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..5351b62 100644 > --- a/drivers/bluetooth/Makefile > +++ b/drivers/bluetooth/Makefile > @@ -28,3 +28,4 @@ hci_uart-$(CONFIG_BT_HCIUART_BCSP) += hci_bcsp.o > hci_uart-$(CONFIG_BT_HCIUART_LL) += hci_ll.o > hci_uart-$(CONFIG_BT_HCIUART_ATH3K) += hci_ath.o > hci_uart-objs := $(hci_uart-y) > +obj-$(CONFIG_BT_WILINK) := btwilink.o sort this after: obj-$(CONFIG_BT_MRVL_SDIO) += btmrvl_sdio.o > diff --git a/drivers/bluetooth/btwilink.c b/drivers/bluetooth/btwilink.c > new file mode 100644 > index 0000000..e0bde79 > --- /dev/null > +++ b/drivers/bluetooth/btwilink.c > @@ -0,0 +1,455 @@ > +/* > + * 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 */ > + > +/** > + * struct ti_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 ti_st_open > + * and ti_st_registration_completion_cb. > + */ > +struct ti_st { > + struct hci_dev *hdev; > + char streg_cbdata; > + long (*st_write) (struct sk_buff *); > + struct completion wait_for_btdrv_reg_completion; wait_for_btdrv_reg_completion is too big. > +}; > + > +static int reset; > + > +/* 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; > + 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 = (struct ti_st *)priv_data; > + /* ti_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 ti_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 st_receive(void *priv_data, struct sk_buff *skb) > +{ > + int err; > + struct ti_st *lhst = (struct ti_st *)priv_data; > + > + if (skb == NULL) { > + BT_ERR("Invalid SKB received from ST"); I don't think this error message is worth. > + return -EFAULT; > + } Make this (!skb) or the check below (lhst == NULL). Try to use only one pattern in your code. > + > + if (!lhst) { > + kfree_skb(skb); > + BT_ERR("Invalid ti_st memory,freeing SKB"); I don't think this error message is worth. > + return -EFAULT; > + } > + > + skb->dev = (struct net_device *)lhst->hdev; Blank line here. > + /* 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", Turn this message into: "Unable to push skb to HCI core(%d)" > + err); > + return err; > + } > + > + lhst->hdev->stat.byte_rx += skb->len; > + return 0; > +} > + > +/* ------- Interfaces to HCI layer ------ */ > + > +/* Called from HCI core to initialize the device */ > +static int ti_st_open(struct hci_dev *hdev) > +{ > + static struct st_proto_s ti_st_proto; Usually we declare this outside of the function like this: static struct usb_driver ath3k_driver = { .name = "ath3k", .probe = ath3k_probe, .disconnect = ath3k_disconnect, .id_table = ath3k_table, }; > + unsigned long timeleft; > + struct ti_st *hst; > + int err; > + err = 0; No need to set err to 0 here. > + > + BT_DBG("%s %p", hdev->name, hdev); Skip a line here. > + hst = hdev->driver_data; > + > + /* Populate BT driver info required by ST */ > + memset(&ti_st_proto, 0, sizeof(ti_st_proto)); > + > + /* BT driver ID */ > + ti_st_proto.type = ST_BT; > + > + /* Receive function which called from ST */ > + ti_st_proto.recv = st_receive; > + > + /* Callback to be called when registration is pending */ > + ti_st_proto.reg_complete_cb = st_registration_completion_cb; > + > + /* send in the hst to be received at registration complete callback > + * and during st's receive > + */ > + ti_st_proto.priv_data = hst; > + > + /* Register with ST layer */ No need for this comment, your function name already set that. > + err = st_register(&ti_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); > + > + /* 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->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__); BT_DBG already have __func__. > + > + timeleft = > + wait_for_completion_timeout this could be: 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 error macro instead of -1 > + BT_ERR("st_register failed %d", err); > + return -EAGAIN; > + } > + > + /* Do we have proper ST write function? */ > + if (ti_st_proto.write != NULL) { > + /* We need this pointer for sending any Bluetooth pkts */ > + hst->st_write = ti_st_proto.write; Didn't get this. Who sets ti_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 > + */ I don't think this comment is worth, your code already says that. But one can argue here that comments are always good. ;) > + set_bit(HCI_RUNNING, &hdev->flags); > + return err; > +} > + > +/* Close device */ > +static int ti_st_close(struct hci_dev *hdev) > +{ > + int err = 0; > + struct ti_st *hst; > + > + hst = hdev->driver_data; > + > + /* Clear HCI device RUNNING flag */ > + if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags)) > + BT_ERR("HCI not RUNNING?"); That's is not a error, just return 0. > + > + /* continue to unregister from transport */ > + err = st_unregister(ST_BT); > + if (err != 0) { > + hst->st_write = NULL; > + BT_ERR("st_unregister failed %d", err); > + return -EBUSY; > + } > + > + hst->st_write = NULL; > + return err; This should be better: if (err) BT_ERR("st_unregister failed %d", err); hst->st_write = NULL; return err; > +} > + > +/* Called from HCI CORE , Sends frames to Shared Transport */ > +static int ti_st_send_frame(struct sk_buff *skb) > +{ > + struct hci_dev *hdev; > + struct ti_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"); Remove the last 3 BT_ERR > + return -EBUSY; > + } > + > + hst = (struct ti_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) { > + 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; > + ti_st_tx_complete(hst, bt_cb(skb)->pkt_type); > + > + return 0; > +} > + > +static void ti_st_destruct(struct hci_dev *hdev) > +{ > + if (!hdev) { > + BT_ERR("Destruct called with invalid HCI Device" > + "(hdev=NULL)"); > + return; > + } > + > + BT_DBG("%s", hdev->name); > + > + /* free ti_st memory */ > + if (hdev->driver_data != NULL) > + kfree(hdev->driver_data); > + > + return; No return; here > +} > + > +/* Creates new HCI device */ > +static int ti_st_register_dev(struct ti_st *hst) > +{ > + struct hci_dev *hdev; > + > + /* Initialize and register HCI device */ > + hdev = hci_alloc_dev(); > + if (!hdev) { > + BT_ERR("Can't allocate HCI device"); > + return -ENOMEM; > + } > + BT_DBG(" HCI device allocated. 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; > + > + if (reset) > + set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks); > + > + if (hci_register_dev(hdev) < 0) { > + BT_ERR("Can't register HCI device"); > + hci_free_dev(hdev); > + return -ENODEV; > + } > + > + BT_DBG(" HCI device registered. hdev= %p", hdev); > + return 0; > +} > + > + > +static int bt_ti_probe(struct platform_device *pdev) > +{ > + int err; > + static struct ti_st *hst; > + err = 0; > + > + BT_DBG(" Bluetooth Driver Version %s", VERSION); > + > + /* Allocate local resource memory */ I don't think this comment is needed. > + hst = kzalloc(sizeof(struct ti_st), GFP_KERNEL); > + if (!hst) { > + BT_ERR("Can't allocate control structure"); remove the BT_ERR > + return -ENFILE; -ENOMEM > + } > + > + /* Expose "hciX" device to user space */ > + err = ti_st_register_dev(hst); > + if (err) { > + /* Release local resource memory */ I don't think this comment is needed. > + kfree(hst); > + > + BT_ERR("Unable to expose hci0 device(%d)", err); Are you sure that this is hci0? > + return err; > + } > + > + dev_set_drvdata(&pdev->dev, hst); > + return err; > +} > + > +static int bt_ti_remove(struct platform_device *pdev) > +{ > + struct ti_st *hst; > + > + hst = dev_get_drvdata(&pdev->dev); > + /* Deallocate local resource's memory */ > + if (hst) { > + struct hci_dev *hdev = hst->hdev; > + if (hdev == NULL) { > + BT_ERR("Invalid hdev memory"); > + kfree(hst); > + } else { > + ti_st_close(hdev); > + hci_unregister_dev(hdev); > + /* Free HCI device memory */ > + hci_free_dev(hdev); > + } > + } > + return 0; > +} > + > +static struct platform_driver bt_ti_driver = { > + .probe = bt_ti_probe, > + .remove = bt_ti_remove, > + .driver = { > + .name = "ti_st_bluetooth", > + .owner = THIS_MODULE, > + }, > +}; > + > +/* ------- Module Init/Exit interfaces ------ */ > +static int __init bt_drv_init(void) > +{ > +long ret = 0; Skip a line and don't set ret to 0. > + ret = platform_driver_register(&bt_ti_driver); > + if (ret != 0) { > + BT_ERR("bt_ti platform drv registration failed"); > + return -1; Why -1? > + } > + return 0; > +} > + > +static void __exit bt_drv_exit(void) > +{ > + platform_driver_unregister(&bt_ti_driver); > +} > + > +module_init(bt_drv_init); > +module_exit(bt_drv_exit); > + > +/* ------ Module Info ------ */ > + > +module_param(reset, bool, 0644); > +MODULE_PARM_DESC(reset, "Send HCI reset command on initialization"); > +MODULE_AUTHOR("Raja Mani "); > +MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION); > +MODULE_VERSION(VERSION); > +MODULE_LICENSE("GPL"); > -- > 1.6.5 > > -- > 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 -- Gustavo F. 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