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  1/*
  2 * Copyright(c) 2015 EZchip Technologies.
  3 *
  4 * This program is free software; you can redistribute it and/or modify it
  5 * under the terms and conditions of the GNU General Public License,
  6 * version 2, as published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope it will be useful, but WITHOUT
  9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 11 * more details.
 12 *
 13 * The full GNU General Public License is included in this distribution in
 14 * the file called "COPYING".
 15 */
 16
 17#include <linux/module.h>
 18#include <linux/etherdevice.h>
 19#include <linux/of_address.h>
 20#include <linux/of_irq.h>
 21#include <linux/of_net.h>
 22#include <linux/of_platform.h>
 23#include "nps_enet.h"
 24
 25#define DRV_NAME			"nps_mgt_enet"
 26
 27static void nps_enet_clean_rx_fifo(struct net_device *ndev, u32 frame_len)
 28{
 29	struct nps_enet_priv *priv = netdev_priv(ndev);
 30	u32 i, len = DIV_ROUND_UP(frame_len, sizeof(u32));
 31
 32	/* Empty Rx FIFO buffer by reading all words */
 33	for (i = 0; i < len; i++)
 34		nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
 35}
 36
 37static void nps_enet_read_rx_fifo(struct net_device *ndev,
 38				  unsigned char *dst, u32 length)
 39{
 40	struct nps_enet_priv *priv = netdev_priv(ndev);
 41	s32 i, last = length & (sizeof(u32) - 1);
 42	u32 *reg = (u32 *)dst, len = length / sizeof(u32);
 43	bool dst_is_aligned = IS_ALIGNED((unsigned long)dst, sizeof(u32));
 44
 45	/* In case dst is not aligned we need an intermediate buffer */
 46	if (dst_is_aligned) {
 47		ioread32_rep(priv->regs_base + NPS_ENET_REG_RX_BUF, reg, len);
 48		reg += len;
 49	}
 50	else { /* !dst_is_aligned */
 51		for (i = 0; i < len; i++, reg++) {
 52			u32 buf = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
 53			put_unaligned_be32(buf, reg);
 54		}
 55	}
 56	/* copy last bytes (if any) */
 57	if (last) {
 58		u32 buf;
 59		ioread32_rep(priv->regs_base + NPS_ENET_REG_RX_BUF, &buf, 1);
 60		memcpy((u8 *)reg, &buf, last);
 61	}
 62}
 63
 64static u32 nps_enet_rx_handler(struct net_device *ndev)
 65{
 66	u32 frame_len, err = 0;
 67	u32 work_done = 0;
 68	struct nps_enet_priv *priv = netdev_priv(ndev);
 69	struct sk_buff *skb;
 70	u32 rx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
 71	u32 rx_ctrl_cr = (rx_ctrl_value & RX_CTL_CR_MASK) >> RX_CTL_CR_SHIFT;
 72	u32 rx_ctrl_er = (rx_ctrl_value & RX_CTL_ER_MASK) >> RX_CTL_ER_SHIFT;
 73	u32 rx_ctrl_crc = (rx_ctrl_value & RX_CTL_CRC_MASK) >> RX_CTL_CRC_SHIFT;
 74
 75	frame_len = (rx_ctrl_value & RX_CTL_NR_MASK) >> RX_CTL_NR_SHIFT;
 76
 77	/* Check if we got RX */
 78	if (!rx_ctrl_cr)
 79		return work_done;
 80
 81	/* If we got here there is a work for us */
 82	work_done++;
 83
 84	/* Check Rx error */
 85	if (rx_ctrl_er) {
 86		ndev->stats.rx_errors++;
 87		err = 1;
 88	}
 89
 90	/* Check Rx CRC error */
 91	if (rx_ctrl_crc) {
 92		ndev->stats.rx_crc_errors++;
 93		ndev->stats.rx_dropped++;
 94		err = 1;
 95	}
 96
 97	/* Check Frame length Min 64b */
 98	if (unlikely(frame_len < ETH_ZLEN)) {
 99		ndev->stats.rx_length_errors++;
100		ndev->stats.rx_dropped++;
101		err = 1;
102	}
103
104	if (err)
105		goto rx_irq_clean;
106
107	/* Skb allocation */
108	skb = netdev_alloc_skb_ip_align(ndev, frame_len);
109	if (unlikely(!skb)) {
110		ndev->stats.rx_errors++;
111		ndev->stats.rx_dropped++;
112		goto rx_irq_clean;
113	}
114
115	/* Copy frame from Rx fifo into the skb */
116	nps_enet_read_rx_fifo(ndev, skb->data, frame_len);
117
118	skb_put(skb, frame_len);
119	skb->protocol = eth_type_trans(skb, ndev);
120	skb->ip_summed = CHECKSUM_UNNECESSARY;
121
122	ndev->stats.rx_packets++;
123	ndev->stats.rx_bytes += frame_len;
124	netif_receive_skb(skb);
125
126	goto rx_irq_frame_done;
127
128rx_irq_clean:
129	/* Clean Rx fifo */
130	nps_enet_clean_rx_fifo(ndev, frame_len);
131
132rx_irq_frame_done:
133	/* Ack Rx ctrl register */
134	nps_enet_reg_set(priv, NPS_ENET_REG_RX_CTL, 0);
135
136	return work_done;
137}
138
139static void nps_enet_tx_handler(struct net_device *ndev)
140{
141	struct nps_enet_priv *priv = netdev_priv(ndev);
142	u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
143	u32 tx_ctrl_ct = (tx_ctrl_value & TX_CTL_CT_MASK) >> TX_CTL_CT_SHIFT;
144	u32 tx_ctrl_et = (tx_ctrl_value & TX_CTL_ET_MASK) >> TX_CTL_ET_SHIFT;
145	u32 tx_ctrl_nt = (tx_ctrl_value & TX_CTL_NT_MASK) >> TX_CTL_NT_SHIFT;
146
147	/* Check if we got TX */
148	if (!priv->tx_skb || tx_ctrl_ct)
149		return;
150
151	/* Ack Tx ctrl register */
152	nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, 0);
153
154	/* Check Tx transmit error */
155	if (unlikely(tx_ctrl_et)) {
156		ndev->stats.tx_errors++;
157	} else {
158		ndev->stats.tx_packets++;
159		ndev->stats.tx_bytes += tx_ctrl_nt;
160	}
161
162	dev_kfree_skb(priv->tx_skb);
163	priv->tx_skb = NULL;
164
165	if (netif_queue_stopped(ndev))
166		netif_wake_queue(ndev);
167}
168
169/**
170 * nps_enet_poll - NAPI poll handler.
171 * @napi:       Pointer to napi_struct structure.
172 * @budget:     How many frames to process on one call.
173 *
174 * returns:     Number of processed frames
175 */
176static int nps_enet_poll(struct napi_struct *napi, int budget)
177{
178	struct net_device *ndev = napi->dev;
179	struct nps_enet_priv *priv = netdev_priv(ndev);
180	u32 work_done;
181
182	nps_enet_tx_handler(ndev);
183	work_done = nps_enet_rx_handler(ndev);
184	if (work_done < budget) {
185		u32 buf_int_enable_value = 0;
186		u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
187		u32 tx_ctrl_ct =
188			(tx_ctrl_value & TX_CTL_CT_MASK) >> TX_CTL_CT_SHIFT;
189
190		napi_complete(napi);
191
192		/* set tx_done and rx_rdy bits */
193		buf_int_enable_value |= NPS_ENET_ENABLE << RX_RDY_SHIFT;
194		buf_int_enable_value |= NPS_ENET_ENABLE << TX_DONE_SHIFT;
195
196		nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
197				 buf_int_enable_value);
198
199		/* in case we will get a tx interrupt while interrupts
200		 * are masked, we will lose it since the tx is edge interrupt.
201		 * specifically, while executing the code section above,
202		 * between nps_enet_tx_handler and the interrupts enable, all
203		 * tx requests will be stuck until we will get an rx interrupt.
204		 * the two code lines below will solve this situation by
205		 * re-adding ourselves to the poll list.
206		 */
207
208		if (priv->tx_skb && !tx_ctrl_ct)
209			napi_reschedule(napi);
210	}
211
212	return work_done;
213}
214
215/**
216 * nps_enet_irq_handler - Global interrupt handler for ENET.
217 * @irq:                irq number.
218 * @dev_instance:       device instance.
219 *
220 * returns: IRQ_HANDLED for all cases.
221 *
222 * EZchip ENET has 2 interrupt causes, and depending on bits raised in
223 * CTRL registers we may tell what is a reason for interrupt to fire up.
224 * We got one for RX and the other for TX (completion).
225 */
226static irqreturn_t nps_enet_irq_handler(s32 irq, void *dev_instance)
227{
228	struct net_device *ndev = dev_instance;
229	struct nps_enet_priv *priv = netdev_priv(ndev);
230	u32 rx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
231	u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
232	u32 tx_ctrl_ct = (tx_ctrl_value & TX_CTL_CT_MASK) >> TX_CTL_CT_SHIFT;
233	u32 rx_ctrl_cr = (rx_ctrl_value & RX_CTL_CR_MASK) >> RX_CTL_CR_SHIFT;
234
235	if ((!tx_ctrl_ct && priv->tx_skb) || rx_ctrl_cr)
236		if (likely(napi_schedule_prep(&priv->napi))) {
237			nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
238			__napi_schedule(&priv->napi);
239		}
240
241	return IRQ_HANDLED;
242}
243
244static void nps_enet_set_hw_mac_address(struct net_device *ndev)
245{
246	struct nps_enet_priv *priv = netdev_priv(ndev);
247	u32 ge_mac_cfg_1_value = 0;
248	u32 *ge_mac_cfg_2_value = &priv->ge_mac_cfg_2_value;
249
250	/* set MAC address in HW */
251	ge_mac_cfg_1_value |= ndev->dev_addr[0] << CFG_1_OCTET_0_SHIFT;
252	ge_mac_cfg_1_value |= ndev->dev_addr[1] << CFG_1_OCTET_1_SHIFT;
253	ge_mac_cfg_1_value |= ndev->dev_addr[2] << CFG_1_OCTET_2_SHIFT;
254	ge_mac_cfg_1_value |= ndev->dev_addr[3] << CFG_1_OCTET_3_SHIFT;
255	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_OCTET_4_MASK)
256		 | ndev->dev_addr[4] << CFG_2_OCTET_4_SHIFT;
257	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_OCTET_5_MASK)
258		 | ndev->dev_addr[5] << CFG_2_OCTET_5_SHIFT;
259
260	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_1,
261			 ge_mac_cfg_1_value);
262
263	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
264			 *ge_mac_cfg_2_value);
265}
266
267/**
268 * nps_enet_hw_reset - Reset the network device.
269 * @ndev:       Pointer to the network device.
270 *
271 * This function reset the PCS and TX fifo.
272 * The programming model is to set the relevant reset bits
273 * wait for some time for this to propagate and then unset
274 * the reset bits. This way we ensure that reset procedure
275 * is done successfully by device.
276 */
277static void nps_enet_hw_reset(struct net_device *ndev)
278{
279	struct nps_enet_priv *priv = netdev_priv(ndev);
280	u32 ge_rst_value = 0, phase_fifo_ctl_value = 0;
281
282	/* Pcs reset sequence*/
283	ge_rst_value |= NPS_ENET_ENABLE << RST_GMAC_0_SHIFT;
284	nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst_value);
285	usleep_range(10, 20);
286	nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst_value);
287
288	/* Tx fifo reset sequence */
289	phase_fifo_ctl_value |= NPS_ENET_ENABLE << PHASE_FIFO_CTL_RST_SHIFT;
290	phase_fifo_ctl_value |= NPS_ENET_ENABLE << PHASE_FIFO_CTL_INIT_SHIFT;
291	nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
292			 phase_fifo_ctl_value);
293	usleep_range(10, 20);
294	phase_fifo_ctl_value = 0;
295	nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
296			 phase_fifo_ctl_value);
297}
298
299static void nps_enet_hw_enable_control(struct net_device *ndev)
300{
301	struct nps_enet_priv *priv = netdev_priv(ndev);
302	u32 ge_mac_cfg_0_value = 0, buf_int_enable_value = 0;
303	u32 *ge_mac_cfg_2_value = &priv->ge_mac_cfg_2_value;
304	u32 *ge_mac_cfg_3_value = &priv->ge_mac_cfg_3_value;
305	s32 max_frame_length;
306
307	/* Enable Rx and Tx statistics */
308	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_STAT_EN_MASK)
309		 | NPS_ENET_GE_MAC_CFG_2_STAT_EN << CFG_2_STAT_EN_SHIFT;
310
311	/* Discard packets with different MAC address */
312	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
313		 | NPS_ENET_ENABLE << CFG_2_DISK_DA_SHIFT;
314
315	/* Discard multicast packets */
316	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
317		 | NPS_ENET_ENABLE << CFG_2_DISK_MC_SHIFT;
318
319	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
320			 *ge_mac_cfg_2_value);
321
322	/* Discard Packets bigger than max frame length */
323	max_frame_length = ETH_HLEN + ndev->mtu + ETH_FCS_LEN;
324	if (max_frame_length <= NPS_ENET_MAX_FRAME_LENGTH) {
325		*ge_mac_cfg_3_value =
326			 (*ge_mac_cfg_3_value & ~CFG_3_MAX_LEN_MASK)
327			 | max_frame_length << CFG_3_MAX_LEN_SHIFT;
328	}
329
330	/* Enable interrupts */
331	buf_int_enable_value |= NPS_ENET_ENABLE << RX_RDY_SHIFT;
332	buf_int_enable_value |= NPS_ENET_ENABLE << TX_DONE_SHIFT;
333	nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
334			 buf_int_enable_value);
335
336	/* Write device MAC address to HW */
337	nps_enet_set_hw_mac_address(ndev);
338
339	/* Rx and Tx HW features */
340	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_PAD_EN_SHIFT;
341	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_CRC_EN_SHIFT;
342	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_CRC_STRIP_SHIFT;
343
344	/* IFG configuration */
345	ge_mac_cfg_0_value |=
346		 NPS_ENET_GE_MAC_CFG_0_RX_IFG << CFG_0_RX_IFG_SHIFT;
347	ge_mac_cfg_0_value |=
348		 NPS_ENET_GE_MAC_CFG_0_TX_IFG << CFG_0_TX_IFG_SHIFT;
349
350	/* preamble configuration */
351	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_PR_CHECK_EN_SHIFT;
352	ge_mac_cfg_0_value |=
353		 NPS_ENET_GE_MAC_CFG_0_TX_PR_LEN << CFG_0_TX_PR_LEN_SHIFT;
354
355	/* enable flow control frames */
356	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_FC_EN_SHIFT;
357	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_FC_EN_SHIFT;
358	ge_mac_cfg_0_value |=
359		 NPS_ENET_GE_MAC_CFG_0_TX_FC_RETR << CFG_0_TX_FC_RETR_SHIFT;
360	*ge_mac_cfg_3_value = (*ge_mac_cfg_3_value & ~CFG_3_CF_DROP_MASK)
361		 | NPS_ENET_ENABLE << CFG_3_CF_DROP_SHIFT;
362
363	/* Enable Rx and Tx */
364	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_EN_SHIFT;
365	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_EN_SHIFT;
366
367	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_3,
368			 *ge_mac_cfg_3_value);
369	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0,
370			 ge_mac_cfg_0_value);
371}
372
373static void nps_enet_hw_disable_control(struct net_device *ndev)
374{
375	struct nps_enet_priv *priv = netdev_priv(ndev);
376
377	/* Disable interrupts */
378	nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
379
380	/* Disable Rx and Tx */
381	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0, 0);
382}
383
384static void nps_enet_send_frame(struct net_device *ndev,
385				struct sk_buff *skb)
386{
387	struct nps_enet_priv *priv = netdev_priv(ndev);
388	u32 tx_ctrl_value = 0;
389	short length = skb->len;
390	u32 i, len = DIV_ROUND_UP(length, sizeof(u32));
391	u32 *src = (void *)skb->data;
392	bool src_is_aligned = IS_ALIGNED((unsigned long)src, sizeof(u32));
393
394	/* In case src is not aligned we need an intermediate buffer */
395	if (src_is_aligned)
396		iowrite32_rep(priv->regs_base + NPS_ENET_REG_TX_BUF, src, len);
397	else /* !src_is_aligned */
398		for (i = 0; i < len; i++, src++)
399			nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF,
400					 get_unaligned_be32(src));
401
402	/* Write the length of the Frame */
403	tx_ctrl_value |= length << TX_CTL_NT_SHIFT;
404
405	tx_ctrl_value |= NPS_ENET_ENABLE << TX_CTL_CT_SHIFT;
406	/* Send Frame */
407	nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, tx_ctrl_value);
408}
409
410/**
411 * nps_enet_set_mac_address - Set the MAC address for this device.
412 * @ndev:       Pointer to net_device structure.
413 * @p:          6 byte Address to be written as MAC address.
414 *
415 * This function copies the HW address from the sockaddr structure to the
416 * net_device structure and updates the address in HW.
417 *
418 * returns:     -EBUSY if the net device is busy or 0 if the address is set
419 *              successfully.
420 */
421static s32 nps_enet_set_mac_address(struct net_device *ndev, void *p)
422{
423	struct sockaddr *addr = p;
424	s32 res;
425
426	if (netif_running(ndev))
427		return -EBUSY;
428
429	res = eth_mac_addr(ndev, p);
430	if (!res) {
431		ether_addr_copy(ndev->dev_addr, addr->sa_data);
432		nps_enet_set_hw_mac_address(ndev);
433	}
434
435	return res;
436}
437
438/**
439 * nps_enet_set_rx_mode - Change the receive filtering mode.
440 * @ndev:       Pointer to the network device.
441 *
442 * This function enables/disables promiscuous mode
443 */
444static void nps_enet_set_rx_mode(struct net_device *ndev)
445{
446	struct nps_enet_priv *priv = netdev_priv(ndev);
447	u32 ge_mac_cfg_2_value = priv->ge_mac_cfg_2_value;
448
449	if (ndev->flags & IFF_PROMISC) {
450		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
451			 | NPS_ENET_DISABLE << CFG_2_DISK_DA_SHIFT;
452		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
453			 | NPS_ENET_DISABLE << CFG_2_DISK_MC_SHIFT;
454
455	} else {
456		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
457			 | NPS_ENET_ENABLE << CFG_2_DISK_DA_SHIFT;
458		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
459			 | NPS_ENET_ENABLE << CFG_2_DISK_MC_SHIFT;
460
461	}
462
463	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2, ge_mac_cfg_2_value);
464}
465
466/**
467 * nps_enet_open - Open the network device.
468 * @ndev:       Pointer to the network device.
469 *
470 * returns: 0, on success or non-zero error value on failure.
471 *
472 * This function sets the MAC address, requests and enables an IRQ
473 * for the ENET device and starts the Tx queue.
474 */
475static s32 nps_enet_open(struct net_device *ndev)
476{
477	struct nps_enet_priv *priv = netdev_priv(ndev);
478	s32 err;
479
480	/* Reset private variables */
481	priv->tx_skb = NULL;
482	priv->ge_mac_cfg_2_value = 0;
483	priv->ge_mac_cfg_3_value = 0;
484
485	/* ge_mac_cfg_3 default values */
486	priv->ge_mac_cfg_3_value |=
487		 NPS_ENET_GE_MAC_CFG_3_RX_IFG_TH << CFG_3_RX_IFG_TH_SHIFT;
488
489	priv->ge_mac_cfg_3_value |=
490		 NPS_ENET_GE_MAC_CFG_3_MAX_LEN << CFG_3_MAX_LEN_SHIFT;
491
492	/* Disable HW device */
493	nps_enet_hw_disable_control(ndev);
494
495	/* irq Rx allocation */
496	err = request_irq(priv->irq, nps_enet_irq_handler,
497			  0, "enet-rx-tx", ndev);
498	if (err)
499		return err;
500
501	napi_enable(&priv->napi);
502
503	/* Enable HW device */
504	nps_enet_hw_reset(ndev);
505	nps_enet_hw_enable_control(ndev);
506
507	netif_start_queue(ndev);
508
509	return 0;
510}
511
512/**
513 * nps_enet_stop - Close the network device.
514 * @ndev:       Pointer to the network device.
515 *
516 * This function stops the Tx queue, disables interrupts for the ENET device.
517 */
518static s32 nps_enet_stop(struct net_device *ndev)
519{
520	struct nps_enet_priv *priv = netdev_priv(ndev);
521
522	napi_disable(&priv->napi);
523	netif_stop_queue(ndev);
524	nps_enet_hw_disable_control(ndev);
525	free_irq(priv->irq, ndev);
526
527	return 0;
528}
529
530/**
531 * nps_enet_start_xmit - Starts the data transmission.
532 * @skb:        sk_buff pointer that contains data to be Transmitted.
533 * @ndev:       Pointer to net_device structure.
534 *
535 * returns: NETDEV_TX_OK, on success
536 *              NETDEV_TX_BUSY, if any of the descriptors are not free.
537 *
538 * This function is invoked from upper layers to initiate transmission.
539 */
540static netdev_tx_t nps_enet_start_xmit(struct sk_buff *skb,
541				       struct net_device *ndev)
542{
543	struct nps_enet_priv *priv = netdev_priv(ndev);
544
545	/* This driver handles one frame at a time  */
546	netif_stop_queue(ndev);
547
548	priv->tx_skb = skb;
549
550	/* make sure tx_skb is actually written to the memory
551	 * before the HW is informed and the IRQ is fired.
552	 */
553	wmb();
554
555	nps_enet_send_frame(ndev, skb);
556
557	return NETDEV_TX_OK;
558}
559
560#ifdef CONFIG_NET_POLL_CONTROLLER
561static void nps_enet_poll_controller(struct net_device *ndev)
562{
563	disable_irq(ndev->irq);
564	nps_enet_irq_handler(ndev->irq, ndev);
565	enable_irq(ndev->irq);
566}
567#endif
568
569static const struct net_device_ops nps_netdev_ops = {
570	.ndo_open		= nps_enet_open,
571	.ndo_stop		= nps_enet_stop,
572	.ndo_start_xmit		= nps_enet_start_xmit,
573	.ndo_set_mac_address	= nps_enet_set_mac_address,
574	.ndo_set_rx_mode        = nps_enet_set_rx_mode,
575#ifdef CONFIG_NET_POLL_CONTROLLER
576	.ndo_poll_controller	= nps_enet_poll_controller,
577#endif
578};
579
580static s32 nps_enet_probe(struct platform_device *pdev)
581{
582	struct device *dev = &pdev->dev;
583	struct net_device *ndev;
584	struct nps_enet_priv *priv;
585	s32 err = 0;
586	const char *mac_addr;
587	struct resource *res_regs;
588
589	if (!dev->of_node)
590		return -ENODEV;
591
592	ndev = alloc_etherdev(sizeof(struct nps_enet_priv));
593	if (!ndev)
594		return -ENOMEM;
595
596	platform_set_drvdata(pdev, ndev);
597	SET_NETDEV_DEV(ndev, dev);
598	priv = netdev_priv(ndev);
599
600	/* The EZ NET specific entries in the device structure. */
601	ndev->netdev_ops = &nps_netdev_ops;
602	ndev->watchdog_timeo = (400 * HZ / 1000);
603	/* FIXME :: no multicast support yet */
604	ndev->flags &= ~IFF_MULTICAST;
605
606	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
607	priv->regs_base = devm_ioremap_resource(dev, res_regs);
608	if (IS_ERR(priv->regs_base)) {
609		err = PTR_ERR(priv->regs_base);
610		goto out_netdev;
611	}
612	dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs_base);
613
614	/* set kernel MAC address to dev */
615	mac_addr = of_get_mac_address(dev->of_node);
616	if (mac_addr)
617		ether_addr_copy(ndev->dev_addr, mac_addr);
618	else
619		eth_hw_addr_random(ndev);
620
621	/* Get IRQ number */
622	priv->irq = platform_get_irq(pdev, 0);
623	if (!priv->irq) {
624		dev_err(dev, "failed to retrieve <irq Rx-Tx> value from device tree\n");
625		err = -ENODEV;
626		goto out_netdev;
627	}
628
629	netif_napi_add(ndev, &priv->napi, nps_enet_poll,
630		       NPS_ENET_NAPI_POLL_WEIGHT);
631
632	/* Register the driver. Should be the last thing in probe */
633	err = register_netdev(ndev);
634	if (err) {
635		dev_err(dev, "Failed to register ndev for %s, err = 0x%08x\n",
636			ndev->name, (s32)err);
637		goto out_netif_api;
638	}
639
640	dev_info(dev, "(rx/tx=%d)\n", priv->irq);
641	return 0;
642
643out_netif_api:
644	netif_napi_del(&priv->napi);
645out_netdev:
646	if (err)
647		free_netdev(ndev);
648
649	return err;
650}
651
652static s32 nps_enet_remove(struct platform_device *pdev)
653{
654	struct net_device *ndev = platform_get_drvdata(pdev);
655	struct nps_enet_priv *priv = netdev_priv(ndev);
656
657	unregister_netdev(ndev);
658	free_netdev(ndev);
659	netif_napi_del(&priv->napi);
660
661	return 0;
662}
663
664static const struct of_device_id nps_enet_dt_ids[] = {
665	{ .compatible = "ezchip,nps-mgt-enet" },
666	{ /* Sentinel */ }
667};
668
669static struct platform_driver nps_enet_driver = {
670	.probe = nps_enet_probe,
671	.remove = nps_enet_remove,
672	.driver = {
673		.name = DRV_NAME,
674		.of_match_table  = nps_enet_dt_ids,
675	},
676};
677
678module_platform_driver(nps_enet_driver);
679
680MODULE_AUTHOR("EZchip Semiconductor");
681MODULE_LICENSE("GPL v2");