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2023-12-06 08f87f769b595151be1afeff53e144f543faa614 
 kernel/drivers/misc/ti-st/st_core.c
....@@ -1,22 +1,9 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
12 /*
23  *  Shared Transport Line discipline driver Core
34  *	This hooks up ST KIM driver and ST LL driver
45  *  Copyright (C) 2009-2010 Texas Instruments
56  *  Author: Pavan Savoy <pavan_savoy@ti.com>
6
- *
7
- *  This program is free software; you can redistribute it and/or modify
8
- *  it under the terms of the GNU General Public License version 2 as
9
- *  published by the Free Software Foundation.
10
- *
11
- *  This program is distributed in the hope that it will be useful,
12
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14
- *  GNU General Public License for more details.
15
- *
16
- *  You should have received a copy of the GNU General Public License
17
- *  along with this program; if not, write to the Free Software
18
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19
- *
207  */
218 
229 #define pr_fmt(fmt)	"(stc): " fmt
....@@ -31,7 +18,8 @@
3118 
3219 extern void st_kim_recv(void *, const unsigned char *, long);
3320 void st_int_recv(void *, const unsigned char *, long);
34
-/* function pointer pointing to either,
21
+/*
22
+ * function pointer pointing to either,
3523  * st_kim_recv during registration to receive fw download responses
3624  * st_int_recv after registration to receive proto stack responses
3725  */
....@@ -73,7 +61,8 @@
7361 	return tty->ops->write_room(tty);
7462 }
7563 
76
-/* can be called in from
64
+/*
65
+ * can be called in from
7766  * -- KIM (during fw download)
7867  * -- ST Core (during st_write)
7968  *
....@@ -113,7 +102,8 @@
113102 		kfree_skb(st_gdata->rx_skb);
114103 		return;
115104 	}
116
-	/* this cannot fail
105
+	/*
106
+	 * this cannot fail
117107 	 * this shouldn't take long
118108 	 * - should be just skb_queue_tail for the
119109 	 *   protocol stack driver
....@@ -134,9 +124,8 @@
134124 	return;
135125 }
136126 
137
-/**
138
- * st_reg_complete -
139
- * to call registration complete callbacks
127
+/*
128
+ * st_reg_complete - to call registration complete callbacks
140129  * of all protocol stack drivers
141130  * This function is being called with spin lock held, protocol drivers are
142131  * only expected to complete their waits and do nothing more than that.
....@@ -169,21 +158,24 @@
169158 	pr_debug("len %d room %d", len, room);
170159 
171160 	if (!len) {
172
-		/* Received packet has only packet header and
161
+		/*
162
+		 * Received packet has only packet header and
173163 		 * has zero length payload. So, ask ST CORE to
174164 		 * forward the packet to protocol driver (BT/FM/GPS)
175165 		 */
176166 		st_send_frame(chnl_id, st_gdata);
177167 
178168 	} else if (len > room) {
179
-		/* Received packet's payload length is larger.
169
+		/*
170
+		 * Received packet's payload length is larger.
180171 		 * We can't accommodate it in created skb.
181172 		 */
182173 		pr_err("Data length is too large len %d room %d", len,
183174 			   room);
184175 		kfree_skb(st_gdata->rx_skb);
185176 	} else {
186
-		/* Packet header has non-zero payload length and
177
+		/*
178
+		 * Packet header has non-zero payload length and
187179 		 * we have enough space in created skb. Lets read
188180 		 * payload data */
189181 		st_gdata->rx_state = ST_W4_DATA;
....@@ -191,8 +183,7 @@
191183 		return len;
192184 	}
193185 
194
-	/* Change ST state to continue to process next
195
-	 * packet */
186
+	/* Change ST state to continue to process next packet */
196187 	st_gdata->rx_state = ST_W4_PACKET_TYPE;
197188 	st_gdata->rx_skb = NULL;
198189 	st_gdata->rx_count = 0;
....@@ -201,7 +192,7 @@
201192 	return 0;
202193 }
203194 
204
-/**
195
+/*
205196  * st_wakeup_ack - internal function for action when wake-up ack
206197  *	received
207198  */
....@@ -212,7 +203,8 @@
212203 	unsigned long flags = 0;
213204 
214205 	spin_lock_irqsave(&st_gdata->lock, flags);
215
-	/* de-Q from waitQ and Q in txQ now that the
206
+	/*
207
+	 * de-Q from waitQ and Q in txQ now that the
216208 	 * chip is awake
217209 	 */
218210 	while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
....@@ -226,7 +218,7 @@
226218 	st_tx_wakeup(st_gdata);
227219 }
228220 
229
-/**
221
+/*
230222  * st_int_recv - ST's internal receive function.
231223  *	Decodes received RAW data and forwards to corresponding
232224  *	client drivers (Bluetooth,FM,GPS..etc).
....@@ -275,8 +267,10 @@
275267 			/* Waiting for complete packet ? */
276268 			case ST_W4_DATA:
277269 				pr_debug("Complete pkt received");
278
-				/* Ask ST CORE to forward
279
-				 * the packet to protocol driver */
270
+				/*
271
+				 * Ask ST CORE to forward
272
+				 * the packet to protocol driver
273
+				 */
280274 				st_send_frame(st_gdata->rx_chnl, st_gdata);
281275 
282276 				st_gdata->rx_state = ST_W4_PACKET_TYPE;
....@@ -289,7 +283,7 @@
289283 				&st_gdata->rx_skb->data
290284 				[proto->offset_len_in_hdr];
291285 				pr_debug("plen pointing to %x\n", *plen);
292
-				if (proto->len_size == 1)/* 1 byte len field */
286
+				if (proto->len_size == 1) /* 1 byte len field */
293287 					payload_len = *(unsigned char *)plen;
294288 				else if (proto->len_size == 2)
295289 					payload_len =
....@@ -307,18 +301,23 @@
307301 		}
308302 
309303 		/* end of if rx_count */
310
-		/* Check first byte of packet and identify module
311
-		 * owner (BT/FM/GPS) */
304
+
305
+		/*
306
+		 * Check first byte of packet and identify module
307
+		 * owner (BT/FM/GPS)
308
+		 */
312309 		switch (*ptr) {
313310 		case LL_SLEEP_IND:
314311 		case LL_SLEEP_ACK:
315312 		case LL_WAKE_UP_IND:
316313 			pr_debug("PM packet");
317
-			/* this takes appropriate action based on
314
+			/*
315
+			 * this takes appropriate action based on
318316 			 * sleep state received --
319317 			 */
320318 			st_ll_sleep_state(st_gdata, *ptr);
321
-			/* if WAKEUP_IND collides copy from waitq to txq
319
+			/*
320
+			 * if WAKEUP_IND collides copy from waitq to txq
322321 			 * and assume chip awake
323322 			 */
324323 			spin_unlock_irqrestore(&st_gdata->lock, flags);
....@@ -344,7 +343,8 @@
344343 		default:
345344 			type = *ptr;
346345 
347
-			/* Default case means non-HCILL packets,
346
+			/*
347
+			 * Default case means non-HCILL packets,
348348 			 * possibilities are packets for:
349349 			 * (a) valid protocol -  Supported Protocols within
350350 			 *     the ST_MAX_CHANNELS.
....@@ -390,7 +390,7 @@
390390 	return;
391391 }
392392 
393
-/**
393
+/*
394394  * st_int_dequeue - internal de-Q function.
395395  *	If the previous data set was not written
396396  *	completely, return that skb which has the pending data.
....@@ -409,7 +409,7 @@
409409 	return skb_dequeue(&st_gdata->txq);
410410 }
411411 
412
-/**
412
+/*
413413  * st_int_enqueue - internal Q-ing function.
414414  *	Will either Q the skb to txq or the tx_waitq
415415  *	depending on the ST LL state.
....@@ -574,7 +574,8 @@
574574 		/* release lock previously held - re-locked below */
575575 		spin_unlock_irqrestore(&st_gdata->lock, flags);
576576 
577
-		/* this may take a while to complete
577
+		/*
578
+		 * this may take a while to complete
578579 		 * since it involves BT fw download
579580 		 */
580581 		err = st_kim_start(st_gdata->kim_data);
....@@ -596,7 +597,8 @@
596597 		clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
597598 		st_recv = st_int_recv;
598599 
599
-		/* this is where all pending registration
600
+		/*
601
+		 * this is where all pending registration
600602 		 * are signalled to be complete by calling callback functions
601603 		 */
602604 		if ((st_gdata->protos_registered != ST_EMPTY) &&
....@@ -606,7 +608,8 @@
606608 		}
607609 		clear_bit(ST_REG_PENDING, &st_gdata->st_state);
608610 
609
-		/* check for already registered once more,
611
+		/*
612
+		 * check for already registered once more,
610613 		 * since the above check is old
611614 		 */
612615 		if (st_gdata->is_registered[new_proto->chnl_id] == true) {
....@@ -635,7 +638,8 @@
635638 }
636639 EXPORT_SYMBOL_GPL(st_register);
637640 
638
-/* to unregister a protocol -
641
+/*
642
+ * to unregister a protocol -
639643  * to be called from protocol stack driver
640644  */
641645 long st_unregister(struct st_proto_s *proto)
....@@ -721,7 +725,6 @@
721725  */
722726 static int st_tty_open(struct tty_struct *tty)
723727 {
724
-	int err = 0;
725728 	struct st_data_s *st_gdata;
726729 	pr_info("%s ", __func__);
727730 
....@@ -744,18 +747,20 @@
744747 	 */
745748 	st_kim_complete(st_gdata->kim_data);
746749 	pr_debug("done %s", __func__);
747
-	return err;
750
+
751
+	return 0;
748752 }
749753 
750754 static void st_tty_close(struct tty_struct *tty)
751755 {
752
-	unsigned char i = ST_MAX_CHANNELS;
753
-	unsigned long flags = 0;
756
+	unsigned char i;
757
+	unsigned long flags;
754758 	struct	st_data_s *st_gdata = tty->disc_data;
755759 
756760 	pr_info("%s ", __func__);
757761 
758
-	/* TODO:
762
+	/*
763
+	 * TODO:
759764 	 * if a protocol has been registered & line discipline
760765 	 * un-installed for some reason - what should be done ?
761766 	 */
....@@ -808,7 +813,8 @@
808813 	pr_debug("done %s", __func__);
809814 }
810815 
811
-/* wake-up function called in from the TTY layer
816
+/*
817
+ * wake-up function called in from the TTY layer
812818  * inside the internal wakeup function will be called
813819  */
814820 static void st_tty_wakeup(struct tty_struct *tty)