xref: /rk3399_rockchip-uboot/drivers/net/davinci_emac.c (revision 09cdd1b9b01450e91786d26ff3c866dc9c8d8d6b)
1 /*
2  * Ethernet driver for TI TMS320DM644x (DaVinci) chips.
3  *
4  * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
5  *
6  * Parts shamelessly stolen from TI's dm644x_emac.c. Original copyright
7  * follows:
8  *
9  * ----------------------------------------------------------------------------
10  *
11  * dm644x_emac.c
12  *
13  * TI DaVinci (DM644X) EMAC peripheral driver source for DV-EVM
14  *
15  * Copyright (C) 2005 Texas Instruments.
16  *
17  * ----------------------------------------------------------------------------
18  *
19  * This program is free software; you can redistribute it and/or modify
20  * it under the terms of the GNU General Public License as published by
21  * the Free Software Foundation; either version 2 of the License, or
22  * (at your option) any later version.
23  *
24  * This program is distributed in the hope that it will be useful,
25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
27  * GNU General Public License for more details.
28  *
29  *  You should have received a copy of the GNU General Public License
30  *  along with this program; if not, write to the Free Software
31  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32  * ----------------------------------------------------------------------------
33 
34  * Modifications:
35  * ver. 1.0: Sep 2005, Anant Gole - Created EMAC version for uBoot.
36  * ver  1.1: Nov 2005, Anant Gole - Extended the RX logic for multiple descriptors
37  *
38  */
39 #include <common.h>
40 #include <command.h>
41 #include <net.h>
42 #include <miiphy.h>
43 #include <asm/arch/emac_defs.h>
44 
45 #ifdef CONFIG_DRIVER_TI_EMAC
46 
47 #ifdef CONFIG_CMD_NET
48 
49 unsigned int	emac_dbg = 0;
50 #define debug_emac(fmt,args...)	if (emac_dbg) printf(fmt,##args)
51 
52 /* Internal static functions */
53 static int davinci_eth_hw_init (void);
54 static int davinci_eth_open (void);
55 static int davinci_eth_close (void);
56 static int davinci_eth_send_packet (volatile void *packet, int length);
57 static int davinci_eth_rcv_packet (void);
58 static void davinci_eth_mdio_enable(void);
59 
60 static int gen_init_phy(int phy_addr);
61 static int gen_is_phy_connected(int phy_addr);
62 static int gen_get_link_speed(int phy_addr);
63 static int gen_auto_negotiate(int phy_addr);
64 
65 /* Wrappers exported to the U-Boot proper */
66 int eth_hw_init(void)
67 {
68 	return(davinci_eth_hw_init());
69 }
70 
71 int eth_init(bd_t * bd)
72 {
73 	return(davinci_eth_open());
74 }
75 
76 void eth_halt(void)
77 {
78 	davinci_eth_close();
79 }
80 
81 int eth_send(volatile void *packet, int length)
82 {
83 	return(davinci_eth_send_packet(packet, length));
84 }
85 
86 int eth_rx(void)
87 {
88 	return(davinci_eth_rcv_packet());
89 }
90 
91 void eth_mdio_enable(void)
92 {
93 	davinci_eth_mdio_enable();
94 }
95 /* End of wrappers */
96 
97 
98 static u_int8_t davinci_eth_mac_addr[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
99 
100 /*
101  * This function must be called before emac_open() if you want to override
102  * the default mac address.
103  */
104 void davinci_eth_set_mac_addr(const u_int8_t *addr)
105 {
106 	int i;
107 
108 	for (i = 0; i < sizeof (davinci_eth_mac_addr); i++) {
109 		davinci_eth_mac_addr[i] = addr[i];
110 	}
111 }
112 
113 /* EMAC Addresses */
114 static volatile emac_regs	*adap_emac = (emac_regs *)EMAC_BASE_ADDR;
115 static volatile ewrap_regs	*adap_ewrap = (ewrap_regs *)EMAC_WRAPPER_BASE_ADDR;
116 static volatile mdio_regs	*adap_mdio = (mdio_regs *)EMAC_MDIO_BASE_ADDR;
117 
118 /* EMAC descriptors */
119 static volatile emac_desc	*emac_rx_desc = (emac_desc *)(EMAC_WRAPPER_RAM_ADDR + EMAC_RX_DESC_BASE);
120 static volatile emac_desc	*emac_tx_desc = (emac_desc *)(EMAC_WRAPPER_RAM_ADDR + EMAC_TX_DESC_BASE);
121 static volatile emac_desc	*emac_rx_active_head = 0;
122 static volatile emac_desc	*emac_rx_active_tail = 0;
123 static int			emac_rx_queue_active = 0;
124 
125 /* Receive packet buffers */
126 static unsigned char		emac_rx_buffers[EMAC_MAX_RX_BUFFERS * (EMAC_MAX_ETHERNET_PKT_SIZE + EMAC_PKT_ALIGN)];
127 
128 /* PHY address for a discovered PHY (0xff - not found) */
129 static volatile u_int8_t	active_phy_addr = 0xff;
130 
131 phy_t				phy;
132 
133 static void davinci_eth_mdio_enable(void)
134 {
135 	u_int32_t	clkdiv;
136 
137 	clkdiv = (EMAC_MDIO_BUS_FREQ / EMAC_MDIO_CLOCK_FREQ) - 1;
138 
139 	adap_mdio->CONTROL = (clkdiv & 0xff) |
140 		MDIO_CONTROL_ENABLE |
141 		MDIO_CONTROL_FAULT |
142 		MDIO_CONTROL_FAULT_ENABLE;
143 
144 	while (adap_mdio->CONTROL & MDIO_CONTROL_IDLE) {;}
145 }
146 
147 /*
148  * Tries to find an active connected PHY. Returns 1 if address if found.
149  * If no active PHY (or more than one PHY) found returns 0.
150  * Sets active_phy_addr variable.
151  */
152 static int davinci_eth_phy_detect(void)
153 {
154 	u_int32_t	phy_act_state;
155 	int		i;
156 
157 	active_phy_addr = 0xff;
158 
159 	if ((phy_act_state = adap_mdio->ALIVE) == 0)
160 		return(0);				/* No active PHYs */
161 
162 	debug_emac("davinci_eth_phy_detect(), ALIVE = 0x%08x\n", phy_act_state);
163 
164 	for (i = 0; i < 32; i++) {
165 		if (phy_act_state & (1 << i)) {
166 			if (phy_act_state & ~(1 << i))
167 				return(0);		/* More than one PHY */
168 			else {
169 				active_phy_addr = i;
170 				return(1);
171 			}
172 		}
173 	}
174 
175 	return(0);	/* Just to make GCC happy */
176 }
177 
178 
179 /* Read a PHY register via MDIO inteface. Returns 1 on success, 0 otherwise */
180 int davinci_eth_phy_read(u_int8_t phy_addr, u_int8_t reg_num, u_int16_t *data)
181 {
182 	int	tmp;
183 
184 	while (adap_mdio->USERACCESS0 & MDIO_USERACCESS0_GO) {;}
185 
186 	adap_mdio->USERACCESS0 = MDIO_USERACCESS0_GO |
187 				MDIO_USERACCESS0_WRITE_READ |
188 				((reg_num & 0x1f) << 21) |
189 				((phy_addr & 0x1f) << 16);
190 
191 	/* Wait for command to complete */
192 	while ((tmp = adap_mdio->USERACCESS0) & MDIO_USERACCESS0_GO) {;}
193 
194 	if (tmp & MDIO_USERACCESS0_ACK) {
195 		*data = tmp & 0xffff;
196 		return(1);
197 	}
198 
199 	*data = -1;
200 	return(0);
201 }
202 
203 /* Write to a PHY register via MDIO inteface. Blocks until operation is complete. */
204 int davinci_eth_phy_write(u_int8_t phy_addr, u_int8_t reg_num, u_int16_t data)
205 {
206 
207 	while (adap_mdio->USERACCESS0 & MDIO_USERACCESS0_GO) {;}
208 
209 	adap_mdio->USERACCESS0 = MDIO_USERACCESS0_GO |
210 				MDIO_USERACCESS0_WRITE_WRITE |
211 				((reg_num & 0x1f) << 21) |
212 				((phy_addr & 0x1f) << 16) |
213 				(data & 0xffff);
214 
215 	/* Wait for command to complete */
216 	while (adap_mdio->USERACCESS0 & MDIO_USERACCESS0_GO) {;}
217 
218 	return(1);
219 }
220 
221 /* PHY functions for a generic PHY */
222 static int gen_init_phy(int phy_addr)
223 {
224 	int	ret = 1;
225 
226 	if (gen_get_link_speed(phy_addr)) {
227 		/* Try another time */
228 		ret = gen_get_link_speed(phy_addr);
229 	}
230 
231 	return(ret);
232 }
233 
234 static int gen_is_phy_connected(int phy_addr)
235 {
236 	u_int16_t	dummy;
237 
238 	return(davinci_eth_phy_read(phy_addr, PHY_PHYIDR1, &dummy));
239 }
240 
241 static int gen_get_link_speed(int phy_addr)
242 {
243 	u_int16_t	tmp;
244 
245 	if (davinci_eth_phy_read(phy_addr, MII_STATUS_REG, &tmp) && (tmp & 0x04))
246 		return(1);
247 
248 	return(0);
249 }
250 
251 static int gen_auto_negotiate(int phy_addr)
252 {
253 	u_int16_t	tmp;
254 
255 	if (!davinci_eth_phy_read(phy_addr, PHY_BMCR, &tmp))
256 		return(0);
257 
258 	/* Restart Auto_negotiation  */
259 	tmp |= PHY_BMCR_AUTON;
260 	davinci_eth_phy_write(phy_addr, PHY_BMCR, tmp);
261 
262 	/*check AutoNegotiate complete */
263 	udelay (10000);
264 	if (!davinci_eth_phy_read(phy_addr, PHY_BMSR, &tmp))
265 		return(0);
266 
267 	if (!(tmp & PHY_BMSR_AUTN_COMP))
268 		return(0);
269 
270 	return(gen_get_link_speed(phy_addr));
271 }
272 /* End of generic PHY functions */
273 
274 
275 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
276 static int davinci_mii_phy_read(char *devname, unsigned char addr, unsigned char reg, unsigned short *value)
277 {
278 	return(davinci_eth_phy_read(addr, reg, value) ? 0 : 1);
279 }
280 
281 static int davinci_mii_phy_write(char *devname, unsigned char addr, unsigned char reg, unsigned short value)
282 {
283 	return(davinci_eth_phy_write(addr, reg, value) ? 0 : 1);
284 }
285 
286 int davinci_eth_miiphy_initialize(bd_t *bis)
287 {
288 	miiphy_register(phy.name, davinci_mii_phy_read, davinci_mii_phy_write);
289 
290 	return(1);
291 }
292 #endif
293 
294 /*
295  * This function initializes the emac hardware. It does NOT initialize
296  * EMAC modules power or pin multiplexors, that is done by board_init()
297  * much earlier in bootup process. Returns 1 on success, 0 otherwise.
298  */
299 static int davinci_eth_hw_init(void)
300 {
301 	u_int32_t	phy_id;
302 	u_int16_t	tmp;
303 	int		i;
304 
305 	davinci_eth_mdio_enable();
306 
307 	for (i = 0; i < 256; i++) {
308 		if (adap_mdio->ALIVE)
309 			break;
310 		udelay(10);
311 	}
312 
313 	if (i >= 256) {
314 		printf("No ETH PHY detected!!!\n");
315 		return(0);
316 	}
317 
318 	/* Find if a PHY is connected and get it's address */
319 	if (!davinci_eth_phy_detect())
320 		return(0);
321 
322 	/* Get PHY ID and initialize phy_ops for a detected PHY */
323 	if (!davinci_eth_phy_read(active_phy_addr, PHY_PHYIDR1, &tmp)) {
324 		active_phy_addr = 0xff;
325 		return(0);
326 	}
327 
328 	phy_id = (tmp << 16) & 0xffff0000;
329 
330 	if (!davinci_eth_phy_read(active_phy_addr, PHY_PHYIDR2, &tmp)) {
331 		active_phy_addr = 0xff;
332 		return(0);
333 	}
334 
335 	phy_id |= tmp & 0x0000ffff;
336 
337 	switch (phy_id) {
338 		case PHY_LXT972:
339 			sprintf(phy.name, "LXT972 @ 0x%02x", active_phy_addr);
340 			phy.init = lxt972_init_phy;
341 			phy.is_phy_connected = lxt972_is_phy_connected;
342 			phy.get_link_speed = lxt972_get_link_speed;
343 			phy.auto_negotiate = lxt972_auto_negotiate;
344 			break;
345 		case PHY_DP83848:
346 			sprintf(phy.name, "DP83848 @ 0x%02x", active_phy_addr);
347 			phy.init = dp83848_init_phy;
348 			phy.is_phy_connected = dp83848_is_phy_connected;
349 			phy.get_link_speed = dp83848_get_link_speed;
350 			phy.auto_negotiate = dp83848_auto_negotiate;
351 			break;
352 		default:
353 			sprintf(phy.name, "GENERIC @ 0x%02x", active_phy_addr);
354 			phy.init = gen_init_phy;
355 			phy.is_phy_connected = gen_is_phy_connected;
356 			phy.get_link_speed = gen_get_link_speed;
357 			phy.auto_negotiate = gen_auto_negotiate;
358 	}
359 
360 	printf("Ethernet PHY: %s\n", phy.name);
361 
362 	return(1);
363 }
364 
365 
366 /* Eth device open */
367 static int davinci_eth_open(void)
368 {
369 	dv_reg_p		addr;
370 	u_int32_t		clkdiv, cnt;
371 	volatile emac_desc	*rx_desc;
372 
373 	debug_emac("+ emac_open\n");
374 
375 	/* Reset EMAC module and disable interrupts in wrapper */
376 	adap_emac->SOFTRESET = 1;
377 	while (adap_emac->SOFTRESET != 0) {;}
378 	adap_ewrap->EWCTL = 0;
379 	for (cnt = 0; cnt < 5; cnt++) {
380 		clkdiv = adap_ewrap->EWCTL;
381 	}
382 
383 	rx_desc = emac_rx_desc;
384 
385 	adap_emac->TXCONTROL = 0x01;
386 	adap_emac->RXCONTROL = 0x01;
387 
388 	/* Set MAC Addresses & Init multicast Hash to 0 (disable any multicast receive) */
389 	/* Using channel 0 only - other channels are disabled */
390 	adap_emac->MACINDEX = 0;
391 	adap_emac->MACADDRHI =
392 		(davinci_eth_mac_addr[3] << 24) |
393 		(davinci_eth_mac_addr[2] << 16) |
394 		(davinci_eth_mac_addr[1] << 8)  |
395 		(davinci_eth_mac_addr[0]);
396 	adap_emac->MACADDRLO =
397 		(davinci_eth_mac_addr[5] << 8) |
398 		(davinci_eth_mac_addr[4]);
399 
400 	adap_emac->MACHASH1 = 0;
401 	adap_emac->MACHASH2 = 0;
402 
403 	/* Set source MAC address - REQUIRED */
404 	adap_emac->MACSRCADDRHI =
405 		(davinci_eth_mac_addr[3] << 24) |
406 		(davinci_eth_mac_addr[2] << 16) |
407 		(davinci_eth_mac_addr[1] << 8)  |
408 		(davinci_eth_mac_addr[0]);
409 	adap_emac->MACSRCADDRLO =
410 		(davinci_eth_mac_addr[4] << 8) |
411 		(davinci_eth_mac_addr[5]);
412 
413 	/* Set DMA 8 TX / 8 RX Head pointers to 0 */
414 	addr = &adap_emac->TX0HDP;
415 	for(cnt = 0; cnt < 16; cnt++)
416 		*addr++ = 0;
417 
418 	addr = &adap_emac->RX0HDP;
419 	for(cnt = 0; cnt < 16; cnt++)
420 		*addr++ = 0;
421 
422 	/* Clear Statistics (do this before setting MacControl register) */
423 	addr = &adap_emac->RXGOODFRAMES;
424 	for(cnt = 0; cnt < EMAC_NUM_STATS; cnt++)
425 		*addr++ = 0;
426 
427 	/* No multicast addressing */
428 	adap_emac->MACHASH1 = 0;
429 	adap_emac->MACHASH2 = 0;
430 
431 	/* Create RX queue and set receive process in place */
432 	emac_rx_active_head = emac_rx_desc;
433 	for (cnt = 0; cnt < EMAC_MAX_RX_BUFFERS; cnt++) {
434 		rx_desc->next = (u_int32_t)(rx_desc + 1);
435 		rx_desc->buffer = &emac_rx_buffers[cnt * (EMAC_MAX_ETHERNET_PKT_SIZE + EMAC_PKT_ALIGN)];
436 		rx_desc->buff_off_len = EMAC_MAX_ETHERNET_PKT_SIZE;
437 		rx_desc->pkt_flag_len = EMAC_CPPI_OWNERSHIP_BIT;
438 		rx_desc++;
439 	}
440 
441 	/* Set the last descriptor's "next" parameter to 0 to end the RX desc list */
442 	rx_desc--;
443 	rx_desc->next = 0;
444 	emac_rx_active_tail = rx_desc;
445 	emac_rx_queue_active = 1;
446 
447 	/* Enable TX/RX */
448 	adap_emac->RXMAXLEN = EMAC_MAX_ETHERNET_PKT_SIZE;
449 	adap_emac->RXBUFFEROFFSET = 0;
450 
451 	/* No fancy configs - Use this for promiscous for debug - EMAC_RXMBPENABLE_RXCAFEN_ENABLE */
452 	adap_emac->RXMBPENABLE = EMAC_RXMBPENABLE_RXBROADEN;
453 
454 	/* Enable ch 0 only */
455 	adap_emac->RXUNICASTSET = 0x01;
456 
457 	/* Enable MII interface and Full duplex mode */
458 	adap_emac->MACCONTROL = (EMAC_MACCONTROL_MIIEN_ENABLE | EMAC_MACCONTROL_FULLDUPLEX_ENABLE);
459 
460 	/* Init MDIO & get link state */
461 	clkdiv = (EMAC_MDIO_BUS_FREQ / EMAC_MDIO_CLOCK_FREQ) - 1;
462 	adap_mdio->CONTROL = ((clkdiv & 0xff) | MDIO_CONTROL_ENABLE | MDIO_CONTROL_FAULT);
463 
464 	if (!phy.get_link_speed(active_phy_addr))
465 		return(0);
466 
467 	/* Start receive process */
468 	adap_emac->RX0HDP = (u_int32_t)emac_rx_desc;
469 
470 	debug_emac("- emac_open\n");
471 
472 	return(1);
473 }
474 
475 /* EMAC Channel Teardown */
476 static void davinci_eth_ch_teardown(int ch)
477 {
478 	dv_reg		dly = 0xff;
479 	dv_reg		cnt;
480 
481 	debug_emac("+ emac_ch_teardown\n");
482 
483 	if (ch == EMAC_CH_TX) {
484 		/* Init TX channel teardown */
485 		adap_emac->TXTEARDOWN = 1;
486 		for(cnt = 0; cnt != 0xfffffffc; cnt = adap_emac->TX0CP) {
487 			/* Wait here for Tx teardown completion interrupt to occur
488 			 * Note: A task delay can be called here to pend rather than
489 			 * occupying CPU cycles - anyway it has been found that teardown
490 			 * takes very few cpu cycles and does not affect functionality */
491 			 dly--;
492 			 udelay(1);
493 			 if (dly == 0)
494 				break;
495 		}
496 		adap_emac->TX0CP = cnt;
497 		adap_emac->TX0HDP = 0;
498 	} else {
499 		/* Init RX channel teardown */
500 		adap_emac->RXTEARDOWN = 1;
501 		for(cnt = 0; cnt != 0xfffffffc; cnt = adap_emac->RX0CP) {
502 			/* Wait here for Rx teardown completion interrupt to occur
503 			 * Note: A task delay can be called here to pend rather than
504 			 * occupying CPU cycles - anyway it has been found that teardown
505 			 * takes very few cpu cycles and does not affect functionality */
506 			 dly--;
507 			 udelay(1);
508 			 if (dly == 0)
509 				break;
510 		}
511 		adap_emac->RX0CP = cnt;
512 		adap_emac->RX0HDP = 0;
513 	}
514 
515 	debug_emac("- emac_ch_teardown\n");
516 }
517 
518 /* Eth device close */
519 static int davinci_eth_close(void)
520 {
521 	debug_emac("+ emac_close\n");
522 
523 	davinci_eth_ch_teardown(EMAC_CH_TX);	/* TX Channel teardown */
524 	davinci_eth_ch_teardown(EMAC_CH_RX);	/* RX Channel teardown */
525 
526 	/* Reset EMAC module and disable interrupts in wrapper */
527 	adap_emac->SOFTRESET = 1;
528 	adap_ewrap->EWCTL = 0;
529 
530 	debug_emac("- emac_close\n");
531 	return(1);
532 }
533 
534 static int tx_send_loop = 0;
535 
536 /*
537  * This function sends a single packet on the network and returns
538  * positive number (number of bytes transmitted) or negative for error
539  */
540 static int davinci_eth_send_packet (volatile void *packet, int length)
541 {
542 	int ret_status = -1;
543 
544 	tx_send_loop = 0;
545 
546 	/* Return error if no link */
547 	if (!phy.get_link_speed (active_phy_addr)) {
548 		printf ("WARN: emac_send_packet: No link\n");
549 		return (ret_status);
550 	}
551 
552 	/* Check packet size and if < EMAC_MIN_ETHERNET_PKT_SIZE, pad it up */
553 	if (length < EMAC_MIN_ETHERNET_PKT_SIZE) {
554 		length = EMAC_MIN_ETHERNET_PKT_SIZE;
555 	}
556 
557 	/* Populate the TX descriptor */
558 	emac_tx_desc->next = 0;
559 	emac_tx_desc->buffer = (u_int8_t *) packet;
560 	emac_tx_desc->buff_off_len = (length & 0xffff);
561 	emac_tx_desc->pkt_flag_len = ((length & 0xffff) |
562 				      EMAC_CPPI_SOP_BIT |
563 				      EMAC_CPPI_OWNERSHIP_BIT |
564 				      EMAC_CPPI_EOP_BIT);
565 	/* Send the packet */
566 	adap_emac->TX0HDP = (unsigned int) emac_tx_desc;
567 
568 	/* Wait for packet to complete or link down */
569 	while (1) {
570 		if (!phy.get_link_speed (active_phy_addr)) {
571 			davinci_eth_ch_teardown (EMAC_CH_TX);
572 			return (ret_status);
573 		}
574 		if (adap_emac->TXINTSTATRAW & 0x01) {
575 			ret_status = length;
576 			break;
577 		}
578 		tx_send_loop++;
579 	}
580 
581 	return (ret_status);
582 }
583 
584 /*
585  * This function handles receipt of a packet from the network
586  */
587 static int davinci_eth_rcv_packet (void)
588 {
589 	volatile emac_desc *rx_curr_desc;
590 	volatile emac_desc *curr_desc;
591 	volatile emac_desc *tail_desc;
592 	int status, ret = -1;
593 
594 	rx_curr_desc = emac_rx_active_head;
595 	status = rx_curr_desc->pkt_flag_len;
596 	if ((rx_curr_desc) && ((status & EMAC_CPPI_OWNERSHIP_BIT) == 0)) {
597 		if (status & EMAC_CPPI_RX_ERROR_FRAME) {
598 			/* Error in packet - discard it and requeue desc */
599 			printf ("WARN: emac_rcv_pkt: Error in packet\n");
600 		} else {
601 			NetReceive (rx_curr_desc->buffer,
602 				    (rx_curr_desc->buff_off_len & 0xffff));
603 			ret = rx_curr_desc->buff_off_len & 0xffff;
604 		}
605 
606 		/* Ack received packet descriptor */
607 		adap_emac->RX0CP = (unsigned int) rx_curr_desc;
608 		curr_desc = rx_curr_desc;
609 		emac_rx_active_head =
610 			(volatile emac_desc *) rx_curr_desc->next;
611 
612 		if (status & EMAC_CPPI_EOQ_BIT) {
613 			if (emac_rx_active_head) {
614 				adap_emac->RX0HDP =
615 					(unsigned int) emac_rx_active_head;
616 			} else {
617 				emac_rx_queue_active = 0;
618 				printf ("INFO:emac_rcv_packet: RX Queue not active\n");
619 			}
620 		}
621 
622 		/* Recycle RX descriptor */
623 		rx_curr_desc->buff_off_len = EMAC_MAX_ETHERNET_PKT_SIZE;
624 		rx_curr_desc->pkt_flag_len = EMAC_CPPI_OWNERSHIP_BIT;
625 		rx_curr_desc->next = 0;
626 
627 		if (emac_rx_active_head == 0) {
628 			printf ("INFO: emac_rcv_pkt: active queue head = 0\n");
629 			emac_rx_active_head = curr_desc;
630 			emac_rx_active_tail = curr_desc;
631 			if (emac_rx_queue_active != 0) {
632 				adap_emac->RX0HDP =
633 					(unsigned int) emac_rx_active_head;
634 				printf ("INFO: emac_rcv_pkt: active queue head = 0, HDP fired\n");
635 				emac_rx_queue_active = 1;
636 			}
637 		} else {
638 			tail_desc = emac_rx_active_tail;
639 			emac_rx_active_tail = curr_desc;
640 			tail_desc->next = (unsigned int) curr_desc;
641 			status = tail_desc->pkt_flag_len;
642 			if (status & EMAC_CPPI_EOQ_BIT) {
643 				adap_emac->RX0HDP = (unsigned int) curr_desc;
644 				status &= ~EMAC_CPPI_EOQ_BIT;
645 				tail_desc->pkt_flag_len = status;
646 			}
647 		}
648 		return (ret);
649 	}
650 	return (0);
651 }
652 
653 #endif /* CONFIG_CMD_NET */
654 
655 #endif /* CONFIG_DRIVER_TI_EMAC */
656