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Subject[PATCH 2/3] drivers:staging:ti-st: cleanup code comments
Date
From: Pavan Savoy <pavan_savoy@ti.com>

cleanup the code commenting in the headers/structures,
also cleanup few inline commenting in the function

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
---
drivers/staging/ti-st/st.h | 44 +++++++++++------------
drivers/staging/ti-st/st_core.c | 54 ++++++++++++++-------------
drivers/staging/ti-st/st_core.h | 74 ++++++++++++++++++++++++++------------
drivers/staging/ti-st/st_kim.c | 52 ++++++++++++++++++---------
drivers/staging/ti-st/st_kim.h | 77 +++++++++++++++++++++++++--------------
drivers/staging/ti-st/st_ll.h | 9 ++++-
6 files changed, 193 insertions(+), 117 deletions(-)
diff --git a/drivers/staging/ti-st/st.h b/drivers/staging/ti-st/st.h
index c4288aa..c96c01e 100644
--- a/drivers/staging/ti-st/st.h
+++ b/drivers/staging/ti-st/st.h
@@ -24,24 +24,24 @@
#define ST_H

#include <linux/skbuff.h>
-/*
- * st.h
- */

/* TODO:
* Move the following to tty.h upon acceptance
*/
#define N_TI_WL 20 /* Ldisc for TI's WL BT, FM, GPS combo chips */

-/* some gpios have active high, others like fm have
- * active low
+/**
+ * enum kim_gpio_state - Few protocols such as FM have ACTIVE LOW
+ * gpio states for their chip/core enable gpios
*/
enum kim_gpio_state {
KIM_GPIO_INACTIVE,
KIM_GPIO_ACTIVE,
};
-/*
- * the list of protocols on chip
+
+/**
+ * enum proto-type - The protocol on WiLink chips which share a
+ * common physical interface like UART.
*/
enum proto_type {
ST_BT,
@@ -50,28 +50,26 @@ enum proto_type {
ST_MAX,
};

-/* per protocol structure
- * for BT/FM and GPS
+/**
+ * struct st_proto_s - Per Protocol structure from BT/FM/GPS to ST
+ * @type: type of the protocol being registered among the
+ * available proto_type(BT, FM, GPS the protocol which share TTY).
+ * @recv: the receiver callback pointing to a function in the
+ * protocol drivers called by the ST driver upon receiving
+ * relevant data.
+ * @match_packet: reserved for future use, to make ST more generic
+ * @reg_complete_cb: callback handler pointing to a function in protocol
+ * handler called by ST when the pending registrations are complete.
+ * The registrations are marked pending, in situations when fw
+ * download is in progress.
+ * @write: pointer to function in ST provided to protocol drivers from ST,
+ * to be made use when protocol drivers have data to send to TTY.
*/
struct st_proto_s {
enum proto_type type;
-/*
- * to be called by ST when data arrives
- */
long (*recv) (struct sk_buff *);
-/*
- * for future use, logic now to be in ST
- */
unsigned char (*match_packet) (const unsigned char *data);
-/*
- * subsequent registration return PENDING,
- * signalled complete by this callback function
- */
void (*reg_complete_cb) (char data);
-/*
- * write function, sent in as NULL and to be returned to
- * protocol drivers
- */
long (*write) (struct sk_buff *skb);
};

diff --git a/drivers/staging/ti-st/st_core.c b/drivers/staging/ti-st/st_core.c
index 7806843..b20ab73 100644
--- a/drivers/staging/ti-st/st_core.c
+++ b/drivers/staging/ti-st/st_core.c
@@ -72,6 +72,7 @@ bool is_protocol_list_empty(void)
return ST_EMPTY;
}
#endif
+
/* can be called in from
* -- KIM (during fw download)
* -- ST Core (during st_write)
@@ -131,7 +132,8 @@ void st_send_frame(enum proto_type protoid, struct st_data_s *st_gdata)
return;
}

-/*
+/**
+ * st_reg_complete -
* to call registration complete callbacks
* of all protocol stack drivers
*/
@@ -185,8 +187,9 @@ static inline int st_check_data_len(struct st_data_s *st_gdata,
return 0;
}

-/* internal function for action when wake-up ack
- * received
+/**
+ * st_wakeup_ack - internal function for action when wake-up ack
+ * received
*/
static inline void st_wakeup_ack(struct st_data_s *st_gdata,
unsigned char cmd)
@@ -209,9 +212,13 @@ static inline void st_wakeup_ack(struct st_data_s *st_gdata,
st_tx_wakeup(st_gdata);
}

-/* Decodes received RAW data and forwards to corresponding
- * client drivers (Bluetooth,FM,GPS..etc).
- *
+/**
+ * st_int_recv - ST's internal receive function.
+ * Decodes received RAW data and forwards to corresponding
+ * client drivers (Bluetooth,FM,GPS..etc).
+ * This can receive various types of packets,
+ * HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
+ * CH-8 packets from FM, CH-9 packets from GPS cores.
*/
void st_int_recv(void *disc_data,
const unsigned char *data, long count)
@@ -438,41 +445,39 @@ void st_int_recv(void *disc_data,
return;
}

-/* internal de-Q function
- * -- return previous in-completely written skb
- * or return the skb in the txQ
+/**
+ * st_int_dequeue - internal de-Q function.
+ * If the previous data set was not written
+ * completely, return that skb which has the pending data.
+ * In normal cases, return top of txq.
*/
struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
{
struct sk_buff *returning_skb;

pr_debug("%s", __func__);
- /* if the previous skb wasn't written completely
- */
if (st_gdata->tx_skb != NULL) {
returning_skb = st_gdata->tx_skb;
st_gdata->tx_skb = NULL;
return returning_skb;
}
-
- /* de-Q from the txQ always if previous write is complete */
return skb_dequeue(&st_gdata->txq);
}

-/* internal Q-ing function
- * will either Q the skb to txq or the tx_waitq
- * depending on the ST LL state
- *
- * lock the whole func - since ll_getstate and Q-ing should happen
- * in one-shot
+/**
+ * st_int_enqueue - internal Q-ing function.
+ * Will either Q the skb to txq or the tx_waitq
+ * depending on the ST LL state.
+ * If the chip is asleep, then Q it onto waitq and
+ * wakeup the chip.
+ * txq and waitq needs protection since the other contexts
+ * may be sending data, waking up chip.
*/
void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
{
unsigned long flags = 0;

pr_debug("%s", __func__);
- /* this function can be invoked in more then one context.
- * so have a lock */
spin_lock_irqsave(&st_gdata->lock, flags);

switch (st_ll_getstate(st_gdata)) {
@@ -483,16 +488,12 @@ void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
case ST_LL_ASLEEP_TO_AWAKE:
skb_queue_tail(&st_gdata->tx_waitq, skb);
break;
- case ST_LL_AWAKE_TO_ASLEEP: /* host cannot be in this state */
+ case ST_LL_AWAKE_TO_ASLEEP:
pr_err("ST LL is illegal state(%ld),"
"purging received skb.", st_ll_getstate(st_gdata));
kfree_skb(skb);
break;
-
case ST_LL_ASLEEP:
- /* call a function of ST LL to put data
- * in tx_waitQ and wake_ind in txQ
- */
skb_queue_tail(&st_gdata->tx_waitq, skb);
st_ll_wakeup(st_gdata);
break;
@@ -502,6 +503,7 @@ void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
kfree_skb(skb);
break;
}
+
spin_unlock_irqrestore(&st_gdata->lock, flags);
pr_debug("done %s", __func__);
return;
diff --git a/drivers/staging/ti-st/st_core.h b/drivers/staging/ti-st/st_core.h
index 53369f2..e0c32d1 100644
--- a/drivers/staging/ti-st/st_core.h
+++ b/drivers/staging/ti-st/st_core.h
@@ -36,59 +36,87 @@
#define ST_REG_PENDING 3
#define ST_WAITING_FOR_RESP 4

-/*
- * local data required for ST/KIM/ST-HCI-LL
+/**
+ * struct st_data_s - ST core internal structure
+ * @st_state: different states of ST like initializing, registration
+ * in progress, this is mainly used to return relevant err codes
+ * when protocol drivers are registering. It is also used to track
+ * the recv function, as in during fw download only HCI events
+ * can occur , where as during other times other events CH8, CH9
+ * can occur.
+ * @tty: tty provided by the TTY core for line disciplines.
+ * @ldisc_ops: the procedures that this line discipline registers with TTY.
+ * @tx_skb: If for some reason the tty's write returns lesser bytes written
+ * then to maintain the rest of data to be written on next instance.
+ * This needs to be protected, hence the lock inside wakeup func.
+ * @tx_state: if the data is being written onto the TTY and protocol driver
+ * wants to send more, queue up data and mark that there is
+ * more data to send.
+ * @list: the list of protocols registered, only MAX can exist, one protocol
+ * can register only once.
+ * @rx_state: states to be maintained inside st's tty receive
+ * @rx_count: count to be maintained inside st's tty receieve
+ * @rx_skb: the skb where all data for a protocol gets accumulated,
+ * since tty might not call receive when a complete event packet
+ * is received, the states, count and the skb needs to be maintained.
+ * @txq: the list of skbs which needs to be sent onto the TTY.
+ * @tx_waitq: if the chip is not in AWAKE state, the skbs needs to be queued
+ * up in here, PM(WAKEUP_IND) data needs to be sent and then the skbs
+ * from waitq can be moved onto the txq.
+ * Needs locking too.
+ * @lock: the lock to protect skbs, queues, and ST states.
+ * @protos_registered: count of the protocols registered, also when 0 the
+ * chip enable gpio can be toggled, and when it changes to 1 the fw
+ * needs to be downloaded to initialize chip side ST.
+ * @ll_state: the various PM states the chip can be, the states are notified
+ * to us, when the chip sends relevant PM packets(SLEEP_IND, WAKE_IND).
+ * @kim_data: reference to the parent encapsulating structure.
+ *
*/
struct st_data_s {
unsigned long st_state;
-/*
- * an instance of tty_struct & ldisc ops to move around
- */
struct tty_struct *tty;
struct tty_ldisc_ops *ldisc_ops;
-/*
- * the tx skb -
- * if the skb is already dequeued and the tty failed to write the same
- * maintain the skb to write in the next transaction
- */
struct sk_buff *tx_skb;
#define ST_TX_SENDING 1
#define ST_TX_WAKEUP 2
unsigned long tx_state;
-/*
- * list of protocol registered
- */
struct st_proto_s *list[ST_MAX];
-/*
- * lock
- */
unsigned long rx_state;
unsigned long rx_count;
struct sk_buff *rx_skb;
struct sk_buff_head txq, tx_waitq;
- spinlock_t lock; /* ST LL state lock */
+ spinlock_t lock;
unsigned char protos_registered;
- unsigned long ll_state; /* ST LL power state */
-/* device reference to kim data */
+ unsigned long ll_state;
void *kim_data;
};

-/* point this to tty->driver->write or tty->ops->write
+/**
+ * st_int_write -
+ * point this to tty->driver->write or tty->ops->write
* depending upon the kernel version
*/
int st_int_write(struct st_data_s*, const unsigned char*, int);
-/* internal write function, passed onto protocol drivers
+
+/**
+ * st_write -
+ * internal write function, passed onto protocol drivers
* via the write function ptr of protocol struct
*/
long st_write(struct sk_buff *);
-/* function to be called from ST-LL
- */
+
+/* function to be called from ST-LL */
void st_ll_send_frame(enum proto_type, struct sk_buff *);
+
/* internal wake up function */
void st_tx_wakeup(struct st_data_s *st_data);

+/* init, exit entry funcs called from KIM */
int st_core_init(struct st_data_s **);
void st_core_exit(struct st_data_s *);
+
+/* ask for reference from KIM */
void st_kim_ref(struct st_data_s **);

#define GPS_STUB_TEST
diff --git a/drivers/staging/ti-st/st_kim.c b/drivers/staging/ti-st/st_kim.c
index 5ab69d1..7e34e4d 100644
--- a/drivers/staging/ti-st/st_kim.c
+++ b/drivers/staging/ti-st/st_kim.c
@@ -104,10 +104,11 @@ const unsigned char *protocol_names[] = {
/**********************************************************************/
/* internal functions */

-/*
- * function to return whether the firmware response was proper
- * in case of error don't complete so that waiting for proper
- * response times out
+/**
+ * validate_firmware_response -
+ * function to return whether the firmware response was proper
+ * in case of error don't complete so that waiting for proper
+ * response times out
*/
void validate_firmware_response(struct kim_data_s *kim_gdata)
{
@@ -158,10 +159,11 @@ static inline int kim_check_data_len(struct kim_data_s *kim_gdata, int len)
return 0;
}

-/* receive function called during firmware download
- * - firmware download responses on different UART drivers
- * have been observed to come in bursts of different
- * tty_receive and hence the logic
+/**
+ * kim_int_recv - receive function called during firmware download
+ * firmware download responses on different UART drivers
+ * have been observed to come in bursts of different
+ * tty_receive and hence the logic
*/
void kim_int_recv(struct kim_data_s *kim_gdata,
const unsigned char *data, long count)
@@ -220,7 +222,7 @@ void kim_int_recv(struct kim_data_s *kim_gdata,
ptr++;
count--;
continue;
- } /* end of switch *ptr */
+ }
ptr++;
count--;
kim_gdata->rx_skb =
@@ -230,9 +232,9 @@ void kim_int_recv(struct kim_data_s *kim_gdata,
kim_gdata->rx_state = ST_W4_PACKET_TYPE;
kim_gdata->rx_count = 0;
return;
- } /* not necessary in this case */
+ }
bt_cb(kim_gdata->rx_skb)->pkt_type = type;
- } /* end of while count */
+ }
pr_info("done %s", __func__);
return;
}
@@ -278,8 +280,10 @@ static long read_local_version(struct kim_data_s *kim_gdata, char *bts_scr_name)
return 0;
}

-/* internal function which parses through the .bts firmware script file
- * intreprets SEND, DELAY actions only as of now
+/**
+ * download_firmware -
+ * internal function which parses through the .bts firmware
+ * script file intreprets SEND, DELAY actions only as of now
*/
static long download_firmware(struct kim_data_s *kim_gdata)
{
@@ -445,8 +449,13 @@ void st_kim_complete(void *kim_data)
complete(&kim_gdata->ldisc_installed);
}

-/* called from ST Core upon 1st registration
-*/
+/**
+ * st_kim_start - called from ST Core upon 1st registration
+ * This involves toggling the chip enable gpio, reading
+ * the firmware version from chip, forming the fw file name
+ * based on the chip version, requesting the fw, parsing it
+ * and perform download(send/recv).
+ */
long st_kim_start(void *kim_data)
{
long err = 0;
@@ -501,8 +510,10 @@ long st_kim_start(void *kim_data)
return err;
}

-/* called from ST Core, on the last un-registration
-*/
+/**
+ * st_kim_stop - called from ST Core, on the last un-registration
+ * toggle low the chip enable gpio
+ */
long st_kim_stop(void *kim_data)
{
long err = 0;
@@ -607,6 +618,13 @@ static int kim_toggle_radio(void *data, bool blocked)
return 0;
}

+/**
+ * st_kim_ref - reference the core's data
+ * This references the per-ST platform device in the arch/xx/
+ * board-xx.c file.
+ * This would enable multiple such platform devices to exist
+ * on a given platform
+ */
void st_kim_ref(struct st_data_s **core_data)
{
struct platform_device *pdev;
diff --git a/drivers/staging/ti-st/st_kim.h b/drivers/staging/ti-st/st_kim.h
index d5685f4..225cacd 100644
--- a/drivers/staging/ti-st/st_kim.h
+++ b/drivers/staging/ti-st/st_kim.h
@@ -43,13 +43,9 @@
* since the self-test for chip takes a while
*/
#define POR_RETRY_COUNT 5
-/*
- * legacy rfkill support where-in 3 rfkill
- * devices are created for the 3 gpios
- * that ST has requested
- */

-/* chip version storage
+/**
+ * struct chip_version - save the chip version
*/
struct chip_version {
unsigned short full;
@@ -58,18 +54,40 @@ struct chip_version {
unsigned short maj_ver;
};

-/*
- * header file for ST provided by KIM
+/**
+ * struct kim_data_s - the KIM internal data, embedded as the
+ * platform's drv data. One for each ST device in the system.
+ * @uim_pid: KIM needs to communicate with UIM to request to install
+ * the ldisc by opening UART when protocol drivers register.
+ * @kim_pdev: the platform device added in one of the board-XX.c file
+ * in arch/XX/ directory, 1 for each ST device.
+ * @kim_rcvd: completion handler to notify when data was received,
+ * mainly used during fw download, which involves multiple send/wait
+ * for each of the HCI-VS commands.
+ * @ldisc_installed: completion handler to notify that the UIM accepted
+ * the request to install ldisc, notify from tty_open which suggests
+ * the ldisc was properly installed.
+ * @resp_buffer: data buffer for the .bts fw file name.
+ * @fw_entry: firmware class struct to request/release the fw.
+ * @gpios: the list of core/chip enable gpios for BT, FM and GPS cores.
+ * @rx_state: the rx state for kim's receive func during fw download.
+ * @rx_count: the rx count for the kim's receive func during fw download.
+ * @rx_skb: all of fw data might not come at once, and hence data storage for
+ * whole of the fw response, only HCI_EVENTs and hence diff from ST's
+ * response.
+ * @rfkill: rfkill data for each of the cores to be registered with rfkill.
+ * @rf_protos: proto types of the data registered with rfkill sub-system.
+ * @core_data: ST core's data, which mainly is the tty's disc_data
+ * @version: chip version available via a sysfs entry.
+ *
*/
struct kim_data_s {
long uim_pid;
struct platform_device *kim_pdev;
struct completion kim_rcvd, ldisc_installed;
- /* MAX len of the .bts firmware script name */
char resp_buffer[30];
const struct firmware *fw_entry;
long gpios[ST_MAX];
-/* used by kim_int_recv to validate fw response */
unsigned long rx_state;
unsigned long rx_count;
struct sk_buff *rx_skb;
@@ -79,20 +97,17 @@ struct kim_data_s {
struct chip_version version;
};

+/**
+ * functions called when 1 of the protocol drivers gets
+ * registered, these need to communicate with UIM to request
+ * ldisc installed, read chip_version, download relevant fw
+ */
long st_kim_start(void *);
long st_kim_stop(void *);
-/*
- * called from st_tty_receive to authenticate fw_download
- */
-void st_kim_recv(void *, const unsigned char *, long count);

+void st_kim_recv(void *, const unsigned char *, long count);
void st_kim_chip_toggle(enum proto_type, enum kim_gpio_state);
-
void st_kim_complete(void *);
-
-/* function called from ST KIM to ST Core, to
- * list out the protocols registered
- */
void kim_st_list_protocols(struct st_data_s *, char *);

/*
@@ -105,9 +120,13 @@ void kim_st_list_protocols(struct st_data_s *, char *);
#define ACTION_RUN_SCRIPT 5
#define ACTION_REMARKS 6

-/*
- * * BRF Firmware header
- * */
+/**
+ * struct bts_header - the fw file is NOT binary which can
+ * be sent onto TTY as is. The .bts is more a script
+ * file which has different types of actions.
+ * Each such action needs to be parsed by the KIM and
+ * relevant procedure to be called.
+ */
struct bts_header {
uint32_t magic;
uint32_t version;
@@ -115,9 +134,10 @@ struct bts_header {
uint8_t actions[0];
} __attribute__ ((packed));

-/*
- * * BRF Actions structure
- * */
+/**
+ * struct bts_action - Each .bts action has its own type of
+ * data.
+ */
struct bts_action {
uint16_t type;
uint16_t size;
@@ -143,8 +163,11 @@ struct bts_action_serial {
uint32_t flow_control;
} __attribute__ ((packed));

-/* for identifying the change speed HCI VS
- * command
+/**
+ * struct hci_command - the HCI-VS for intrepreting
+ * the change baud rate of host-side UART, which
+ * needs to be ignored, since UIM would do that
+ * when it receives request from KIM for ldisc installation.
*/
struct hci_command {
uint8_t prefix;
diff --git a/drivers/staging/ti-st/st_ll.h b/drivers/staging/ti-st/st_ll.h
index 77dfbf0..e4dfacd 100644
--- a/drivers/staging/ti-st/st_ll.h
+++ b/drivers/staging/ti-st/st_ll.h
@@ -41,6 +41,7 @@
#define ST_LL_AWAKE_TO_ASLEEP 3
#define ST_LL_INVALID 4

+/* different PM notifications coming from chip */
#define LL_SLEEP_IND 0x30
#define LL_SLEEP_ACK 0x31
#define LL_WAKE_UP_IND 0x32
@@ -50,13 +51,19 @@
long st_ll_init(struct st_data_s *);
long st_ll_deinit(struct st_data_s *);

-/* enable/disable ST LL along with KIM start/stop
+/**
+ * enable/disable ST LL along with KIM start/stop
* called by ST Core
*/
void st_ll_enable(struct st_data_s *);
void st_ll_disable(struct st_data_s *);

+/**
+ * various funcs used by ST core to set/get the various PM states
+ * of the chip.
+ */
unsigned long st_ll_getstate(struct st_data_s *);
unsigned long st_ll_sleep_state(struct st_data_s *, unsigned char);
void st_ll_wakeup(struct st_data_s *);
+
#endif /* ST_LL_H */
--
1.5.6.3


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