1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright(c) 2015 EZchip Technologies.
4 */
5
6 #include <linux/module.h>
7 #include <linux/etherdevice.h>
8 #include <linux/interrupt.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/of_net.h>
11 #include <linux/platform_device.h>
12 #include "nps_enet.h"
13
14 #define DRV_NAME "nps_mgt_enet"
15
nps_enet_is_tx_pending(struct nps_enet_priv * priv)16 static inline bool nps_enet_is_tx_pending(struct nps_enet_priv *priv)
17 {
18 u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
19 u32 tx_ctrl_ct = (tx_ctrl_value & TX_CTL_CT_MASK) >> TX_CTL_CT_SHIFT;
20
21 return (!tx_ctrl_ct && priv->tx_skb);
22 }
23
nps_enet_clean_rx_fifo(struct net_device * ndev,u32 frame_len)24 static void nps_enet_clean_rx_fifo(struct net_device *ndev, u32 frame_len)
25 {
26 struct nps_enet_priv *priv = netdev_priv(ndev);
27 u32 i, len = DIV_ROUND_UP(frame_len, sizeof(u32));
28
29 /* Empty Rx FIFO buffer by reading all words */
30 for (i = 0; i < len; i++)
31 nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
32 }
33
nps_enet_read_rx_fifo(struct net_device * ndev,unsigned char * dst,u32 length)34 static void nps_enet_read_rx_fifo(struct net_device *ndev,
35 unsigned char *dst, u32 length)
36 {
37 struct nps_enet_priv *priv = netdev_priv(ndev);
38 s32 i, last = length & (sizeof(u32) - 1);
39 u32 *reg = (u32 *)dst, len = length / sizeof(u32);
40 bool dst_is_aligned = IS_ALIGNED((unsigned long)dst, sizeof(u32));
41
42 /* In case dst is not aligned we need an intermediate buffer */
43 if (dst_is_aligned) {
44 ioread32_rep(priv->regs_base + NPS_ENET_REG_RX_BUF, reg, len);
45 reg += len;
46 } else { /* !dst_is_aligned */
47 for (i = 0; i < len; i++, reg++) {
48 u32 buf = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
49
50 put_unaligned_be32(buf, reg);
51 }
52 }
53 /* copy last bytes (if any) */
54 if (last) {
55 u32 buf;
56
57 ioread32_rep(priv->regs_base + NPS_ENET_REG_RX_BUF, &buf, 1);
58 memcpy((u8 *)reg, &buf, last);
59 }
60 }
61
nps_enet_rx_handler(struct net_device * ndev)62 static u32 nps_enet_rx_handler(struct net_device *ndev)
63 {
64 u32 frame_len, err = 0;
65 u32 work_done = 0;
66 struct nps_enet_priv *priv = netdev_priv(ndev);
67 struct sk_buff *skb;
68 u32 rx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
69 u32 rx_ctrl_cr = (rx_ctrl_value & RX_CTL_CR_MASK) >> RX_CTL_CR_SHIFT;
70 u32 rx_ctrl_er = (rx_ctrl_value & RX_CTL_ER_MASK) >> RX_CTL_ER_SHIFT;
71 u32 rx_ctrl_crc = (rx_ctrl_value & RX_CTL_CRC_MASK) >> RX_CTL_CRC_SHIFT;
72
73 frame_len = (rx_ctrl_value & RX_CTL_NR_MASK) >> RX_CTL_NR_SHIFT;
74
75 /* Check if we got RX */
76 if (!rx_ctrl_cr)
77 return work_done;
78
79 /* If we got here there is a work for us */
80 work_done++;
81
82 /* Check Rx error */
83 if (rx_ctrl_er) {
84 ndev->stats.rx_errors++;
85 err = 1;
86 }
87
88 /* Check Rx CRC error */
89 if (rx_ctrl_crc) {
90 ndev->stats.rx_crc_errors++;
91 ndev->stats.rx_dropped++;
92 err = 1;
93 }
94
95 /* Check Frame length Min 64b */
96 if (unlikely(frame_len < ETH_ZLEN)) {
97 ndev->stats.rx_length_errors++;
98 ndev->stats.rx_dropped++;
99 err = 1;
100 }
101
102 if (err)
103 goto rx_irq_clean;
104
105 /* Skb allocation */
106 skb = netdev_alloc_skb_ip_align(ndev, frame_len);
107 if (unlikely(!skb)) {
108 ndev->stats.rx_errors++;
109 ndev->stats.rx_dropped++;
110 goto rx_irq_clean;
111 }
112
113 /* Copy frame from Rx fifo into the skb */
114 nps_enet_read_rx_fifo(ndev, skb->data, frame_len);
115
116 skb_put(skb, frame_len);
117 skb->protocol = eth_type_trans(skb, ndev);
118 skb->ip_summed = CHECKSUM_UNNECESSARY;
119
120 ndev->stats.rx_packets++;
121 ndev->stats.rx_bytes += frame_len;
122 netif_receive_skb(skb);
123
124 goto rx_irq_frame_done;
125
126 rx_irq_clean:
127 /* Clean Rx fifo */
128 nps_enet_clean_rx_fifo(ndev, frame_len);
129
130 rx_irq_frame_done:
131 /* Ack Rx ctrl register */
132 nps_enet_reg_set(priv, NPS_ENET_REG_RX_CTL, 0);
133
134 return work_done;
135 }
136
nps_enet_tx_handler(struct net_device * ndev)137 static void nps_enet_tx_handler(struct net_device *ndev)
138 {
139 struct nps_enet_priv *priv = netdev_priv(ndev);
140 u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
141 u32 tx_ctrl_et = (tx_ctrl_value & TX_CTL_ET_MASK) >> TX_CTL_ET_SHIFT;
142 u32 tx_ctrl_nt = (tx_ctrl_value & TX_CTL_NT_MASK) >> TX_CTL_NT_SHIFT;
143
144 /* Check if we got TX */
145 if (!nps_enet_is_tx_pending(priv))
146 return;
147
148 /* Ack Tx ctrl register */
149 nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, 0);
150
151 /* Check Tx transmit error */
152 if (unlikely(tx_ctrl_et)) {
153 ndev->stats.tx_errors++;
154 } else {
155 ndev->stats.tx_packets++;
156 ndev->stats.tx_bytes += tx_ctrl_nt;
157 }
158
159 dev_kfree_skb(priv->tx_skb);
160 priv->tx_skb = NULL;
161
162 if (netif_queue_stopped(ndev))
163 netif_wake_queue(ndev);
164 }
165
166 /**
167 * nps_enet_poll - NAPI poll handler.
168 * @napi: Pointer to napi_struct structure.
169 * @budget: How many frames to process on one call.
170 *
171 * returns: Number of processed frames
172 */
nps_enet_poll(struct napi_struct * napi,int budget)173 static int nps_enet_poll(struct napi_struct *napi, int budget)
174 {
175 struct net_device *ndev = napi->dev;
176 struct nps_enet_priv *priv = netdev_priv(ndev);
177 u32 work_done;
178
179 nps_enet_tx_handler(ndev);
180 work_done = nps_enet_rx_handler(ndev);
181 if ((work_done < budget) && napi_complete_done(napi, work_done)) {
182 u32 buf_int_enable_value = 0;
183
184 /* set tx_done and rx_rdy bits */
185 buf_int_enable_value |= NPS_ENET_ENABLE << RX_RDY_SHIFT;
186 buf_int_enable_value |= NPS_ENET_ENABLE << TX_DONE_SHIFT;
187
188 nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
189 buf_int_enable_value);
190
191 /* in case we will get a tx interrupt while interrupts
192 * are masked, we will lose it since the tx is edge interrupt.
193 * specifically, while executing the code section above,
194 * between nps_enet_tx_handler and the interrupts enable, all
195 * tx requests will be stuck until we will get an rx interrupt.
196 * the two code lines below will solve this situation by
197 * re-adding ourselves to the poll list.
198 */
199 if (nps_enet_is_tx_pending(priv)) {
200 nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
201 napi_schedule(napi);
202 }
203 }
204
205 return work_done;
206 }
207
208 /**
209 * nps_enet_irq_handler - Global interrupt handler for ENET.
210 * @irq: irq number.
211 * @dev_instance: device instance.
212 *
213 * returns: IRQ_HANDLED for all cases.
214 *
215 * EZchip ENET has 2 interrupt causes, and depending on bits raised in
216 * CTRL registers we may tell what is a reason for interrupt to fire up.
217 * We got one for RX and the other for TX (completion).
218 */
nps_enet_irq_handler(s32 irq,void * dev_instance)219 static irqreturn_t nps_enet_irq_handler(s32 irq, void *dev_instance)
220 {
221 struct net_device *ndev = dev_instance;
222 struct nps_enet_priv *priv = netdev_priv(ndev);
223 u32 rx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
224 u32 rx_ctrl_cr = (rx_ctrl_value & RX_CTL_CR_MASK) >> RX_CTL_CR_SHIFT;
225
226 if (nps_enet_is_tx_pending(priv) || rx_ctrl_cr)
227 if (likely(napi_schedule_prep(&priv->napi))) {
228 nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
229 __napi_schedule(&priv->napi);
230 }
231
232 return IRQ_HANDLED;
233 }
234
nps_enet_set_hw_mac_address(struct net_device * ndev)235 static void nps_enet_set_hw_mac_address(struct net_device *ndev)
236 {
237 struct nps_enet_priv *priv = netdev_priv(ndev);
238 u32 ge_mac_cfg_1_value = 0;
239 u32 *ge_mac_cfg_2_value = &priv->ge_mac_cfg_2_value;
240
241 /* set MAC address in HW */
242 ge_mac_cfg_1_value |= ndev->dev_addr[0] << CFG_1_OCTET_0_SHIFT;
243 ge_mac_cfg_1_value |= ndev->dev_addr[1] << CFG_1_OCTET_1_SHIFT;
244 ge_mac_cfg_1_value |= ndev->dev_addr[2] << CFG_1_OCTET_2_SHIFT;
245 ge_mac_cfg_1_value |= ndev->dev_addr[3] << CFG_1_OCTET_3_SHIFT;
246 *ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_OCTET_4_MASK)
247 | ndev->dev_addr[4] << CFG_2_OCTET_4_SHIFT;
248 *ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_OCTET_5_MASK)
249 | ndev->dev_addr[5] << CFG_2_OCTET_5_SHIFT;
250
251 nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_1,
252 ge_mac_cfg_1_value);
253
254 nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
255 *ge_mac_cfg_2_value);
256 }
257
258 /**
259 * nps_enet_hw_reset - Reset the network device.
260 * @ndev: Pointer to the network device.
261 *
262 * This function reset the PCS and TX fifo.
263 * The programming model is to set the relevant reset bits
264 * wait for some time for this to propagate and then unset
265 * the reset bits. This way we ensure that reset procedure
266 * is done successfully by device.
267 */
nps_enet_hw_reset(struct net_device * ndev)268 static void nps_enet_hw_reset(struct net_device *ndev)
269 {
270 struct nps_enet_priv *priv = netdev_priv(ndev);
271 u32 ge_rst_value = 0, phase_fifo_ctl_value = 0;
272
273 /* Pcs reset sequence*/
274 ge_rst_value |= NPS_ENET_ENABLE << RST_GMAC_0_SHIFT;
275 nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst_value);
276 usleep_range(10, 20);
277 ge_rst_value = 0;
278 nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst_value);
279
280 /* Tx fifo reset sequence */
281 phase_fifo_ctl_value |= NPS_ENET_ENABLE << PHASE_FIFO_CTL_RST_SHIFT;
282 phase_fifo_ctl_value |= NPS_ENET_ENABLE << PHASE_FIFO_CTL_INIT_SHIFT;
283 nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
284 phase_fifo_ctl_value);
285 usleep_range(10, 20);
286 phase_fifo_ctl_value = 0;
287 nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
288 phase_fifo_ctl_value);
289 }
290
nps_enet_hw_enable_control(struct net_device * ndev)291 static void nps_enet_hw_enable_control(struct net_device *ndev)
292 {
293 struct nps_enet_priv *priv = netdev_priv(ndev);
294 u32 ge_mac_cfg_0_value = 0, buf_int_enable_value = 0;
295 u32 *ge_mac_cfg_2_value = &priv->ge_mac_cfg_2_value;
296 u32 *ge_mac_cfg_3_value = &priv->ge_mac_cfg_3_value;
297 s32 max_frame_length;
298
299 /* Enable Rx and Tx statistics */
300 *ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_STAT_EN_MASK)
301 | NPS_ENET_GE_MAC_CFG_2_STAT_EN << CFG_2_STAT_EN_SHIFT;
302
303 /* Discard packets with different MAC address */
304 *ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
305 | NPS_ENET_ENABLE << CFG_2_DISK_DA_SHIFT;
306
307 /* Discard multicast packets */
308 *ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
309 | NPS_ENET_ENABLE << CFG_2_DISK_MC_SHIFT;
310
311 nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
312 *ge_mac_cfg_2_value);
313
314 /* Discard Packets bigger than max frame length */
315 max_frame_length = ETH_HLEN + ndev->mtu + ETH_FCS_LEN;
316 if (max_frame_length <= NPS_ENET_MAX_FRAME_LENGTH) {
317 *ge_mac_cfg_3_value =
318 (*ge_mac_cfg_3_value & ~CFG_3_MAX_LEN_MASK)
319 | max_frame_length << CFG_3_MAX_LEN_SHIFT;
320 }
321
322 /* Enable interrupts */
323 buf_int_enable_value |= NPS_ENET_ENABLE << RX_RDY_SHIFT;
324 buf_int_enable_value |= NPS_ENET_ENABLE << TX_DONE_SHIFT;
325 nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
326 buf_int_enable_value);
327
328 /* Write device MAC address to HW */
329 nps_enet_set_hw_mac_address(ndev);
330
331 /* Rx and Tx HW features */
332 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_PAD_EN_SHIFT;
333 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_CRC_EN_SHIFT;
334 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_CRC_STRIP_SHIFT;
335
336 /* IFG configuration */
337 ge_mac_cfg_0_value |=
338 NPS_ENET_GE_MAC_CFG_0_RX_IFG << CFG_0_RX_IFG_SHIFT;
339 ge_mac_cfg_0_value |=
340 NPS_ENET_GE_MAC_CFG_0_TX_IFG << CFG_0_TX_IFG_SHIFT;
341
342 /* preamble configuration */
343 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_PR_CHECK_EN_SHIFT;
344 ge_mac_cfg_0_value |=
345 NPS_ENET_GE_MAC_CFG_0_TX_PR_LEN << CFG_0_TX_PR_LEN_SHIFT;
346
347 /* enable flow control frames */
348 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_FC_EN_SHIFT;
349 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_FC_EN_SHIFT;
350 ge_mac_cfg_0_value |=
351 NPS_ENET_GE_MAC_CFG_0_TX_FC_RETR << CFG_0_TX_FC_RETR_SHIFT;
352 *ge_mac_cfg_3_value = (*ge_mac_cfg_3_value & ~CFG_3_CF_DROP_MASK)
353 | NPS_ENET_ENABLE << CFG_3_CF_DROP_SHIFT;
354
355 /* Enable Rx and Tx */
356 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_EN_SHIFT;
357 ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_EN_SHIFT;
358
359 nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_3,
360 *ge_mac_cfg_3_value);
361 nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0,
362 ge_mac_cfg_0_value);
363 }
364
nps_enet_hw_disable_control(struct net_device * ndev)365 static void nps_enet_hw_disable_control(struct net_device *ndev)
366 {
367 struct nps_enet_priv *priv = netdev_priv(ndev);
368
369 /* Disable interrupts */
370 nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
371
372 /* Disable Rx and Tx */
373 nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0, 0);
374 }
375
nps_enet_send_frame(struct net_device * ndev,struct sk_buff * skb)376 static void nps_enet_send_frame(struct net_device *ndev,
377 struct sk_buff *skb)
378 {
379 struct nps_enet_priv *priv = netdev_priv(ndev);
380 u32 tx_ctrl_value = 0;
381 short length = skb->len;
382 u32 i, len = DIV_ROUND_UP(length, sizeof(u32));
383 u32 *src = (void *)skb->data;
384 bool src_is_aligned = IS_ALIGNED((unsigned long)src, sizeof(u32));
385
386 /* In case src is not aligned we need an intermediate buffer */
387 if (src_is_aligned)
388 iowrite32_rep(priv->regs_base + NPS_ENET_REG_TX_BUF, src, len);
389 else /* !src_is_aligned */
390 for (i = 0; i < len; i++, src++)
391 nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF,
392 get_unaligned_be32(src));
393
394 /* Write the length of the Frame */
395 tx_ctrl_value |= length << TX_CTL_NT_SHIFT;
396
397 tx_ctrl_value |= NPS_ENET_ENABLE << TX_CTL_CT_SHIFT;
398 /* Send Frame */
399 nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, tx_ctrl_value);
400 }
401
402 /**
403 * nps_enet_set_mac_address - Set the MAC address for this device.
404 * @ndev: Pointer to net_device structure.
405 * @p: 6 byte Address to be written as MAC address.
406 *
407 * This function copies the HW address from the sockaddr structure to the
408 * net_device structure and updates the address in HW.
409 *
410 * returns: -EBUSY if the net device is busy or 0 if the address is set
411 * successfully.
412 */
nps_enet_set_mac_address(struct net_device * ndev,void * p)413 static s32 nps_enet_set_mac_address(struct net_device *ndev, void *p)
414 {
415 struct sockaddr *addr = p;
416 s32 res;
417
418 if (netif_running(ndev))
419 return -EBUSY;
420
421 res = eth_mac_addr(ndev, p);
422 if (!res) {
423 eth_hw_addr_set(ndev, addr->sa_data);
424 nps_enet_set_hw_mac_address(ndev);
425 }
426
427 return res;
428 }
429
430 /**
431 * nps_enet_set_rx_mode - Change the receive filtering mode.
432 * @ndev: Pointer to the network device.
433 *
434 * This function enables/disables promiscuous mode
435 */
nps_enet_set_rx_mode(struct net_device * ndev)436 static void nps_enet_set_rx_mode(struct net_device *ndev)
437 {
438 struct nps_enet_priv *priv = netdev_priv(ndev);
439 u32 ge_mac_cfg_2_value = priv->ge_mac_cfg_2_value;
440
441 if (ndev->flags & IFF_PROMISC) {
442 ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
443 | NPS_ENET_DISABLE << CFG_2_DISK_DA_SHIFT;
444 ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
445 | NPS_ENET_DISABLE << CFG_2_DISK_MC_SHIFT;
446
447 } else {
448 ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
449 | NPS_ENET_ENABLE << CFG_2_DISK_DA_SHIFT;
450 ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
451 | NPS_ENET_ENABLE << CFG_2_DISK_MC_SHIFT;
452 }
453
454 nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2, ge_mac_cfg_2_value);
455 }
456
457 /**
458 * nps_enet_open - Open the network device.
459 * @ndev: Pointer to the network device.
460 *
461 * returns: 0, on success or non-zero error value on failure.
462 *
463 * This function sets the MAC address, requests and enables an IRQ
464 * for the ENET device and starts the Tx queue.
465 */
nps_enet_open(struct net_device * ndev)466 static s32 nps_enet_open(struct net_device *ndev)
467 {
468 struct nps_enet_priv *priv = netdev_priv(ndev);
469 s32 err;
470
471 /* Reset private variables */
472 priv->tx_skb = NULL;
473 priv->ge_mac_cfg_2_value = 0;
474 priv->ge_mac_cfg_3_value = 0;
475
476 /* ge_mac_cfg_3 default values */
477 priv->ge_mac_cfg_3_value |=
478 NPS_ENET_GE_MAC_CFG_3_RX_IFG_TH << CFG_3_RX_IFG_TH_SHIFT;
479
480 priv->ge_mac_cfg_3_value |=
481 NPS_ENET_GE_MAC_CFG_3_MAX_LEN << CFG_3_MAX_LEN_SHIFT;
482
483 /* Disable HW device */
484 nps_enet_hw_disable_control(ndev);
485
486 /* irq Rx allocation */
487 err = request_irq(priv->irq, nps_enet_irq_handler,
488 0, "enet-rx-tx", ndev);
489 if (err)
490 return err;
491
492 napi_enable(&priv->napi);
493
494 /* Enable HW device */
495 nps_enet_hw_reset(ndev);
496 nps_enet_hw_enable_control(ndev);
497
498 netif_start_queue(ndev);
499
500 return 0;
501 }
502
503 /**
504 * nps_enet_stop - Close the network device.
505 * @ndev: Pointer to the network device.
506 *
507 * This function stops the Tx queue, disables interrupts for the ENET device.
508 */
nps_enet_stop(struct net_device * ndev)509 static s32 nps_enet_stop(struct net_device *ndev)
510 {
511 struct nps_enet_priv *priv = netdev_priv(ndev);
512
513 napi_disable(&priv->napi);
514 netif_stop_queue(ndev);
515 nps_enet_hw_disable_control(ndev);
516 free_irq(priv->irq, ndev);
517
518 return 0;
519 }
520
521 /**
522 * nps_enet_start_xmit - Starts the data transmission.
523 * @skb: sk_buff pointer that contains data to be Transmitted.
524 * @ndev: Pointer to net_device structure.
525 *
526 * returns: NETDEV_TX_OK, on success
527 * NETDEV_TX_BUSY, if any of the descriptors are not free.
528 *
529 * This function is invoked from upper layers to initiate transmission.
530 */
nps_enet_start_xmit(struct sk_buff * skb,struct net_device * ndev)531 static netdev_tx_t nps_enet_start_xmit(struct sk_buff *skb,
532 struct net_device *ndev)
533 {
534 struct nps_enet_priv *priv = netdev_priv(ndev);
535
536 /* This driver handles one frame at a time */
537 netif_stop_queue(ndev);
538
539 priv->tx_skb = skb;
540
541 /* make sure tx_skb is actually written to the memory
542 * before the HW is informed and the IRQ is fired.
543 */
544 wmb();
545
546 nps_enet_send_frame(ndev, skb);
547
548 return NETDEV_TX_OK;
549 }
550
551 #ifdef CONFIG_NET_POLL_CONTROLLER
nps_enet_poll_controller(struct net_device * ndev)552 static void nps_enet_poll_controller(struct net_device *ndev)
553 {
554 disable_irq(ndev->irq);
555 nps_enet_irq_handler(ndev->irq, ndev);
556 enable_irq(ndev->irq);
557 }
558 #endif
559
560 static const struct net_device_ops nps_netdev_ops = {
561 .ndo_open = nps_enet_open,
562 .ndo_stop = nps_enet_stop,
563 .ndo_start_xmit = nps_enet_start_xmit,
564 .ndo_set_mac_address = nps_enet_set_mac_address,
565 .ndo_set_rx_mode = nps_enet_set_rx_mode,
566 #ifdef CONFIG_NET_POLL_CONTROLLER
567 .ndo_poll_controller = nps_enet_poll_controller,
568 #endif
569 };
570
nps_enet_probe(struct platform_device * pdev)571 static s32 nps_enet_probe(struct platform_device *pdev)
572 {
573 struct device *dev = &pdev->dev;
574 struct net_device *ndev;
575 struct nps_enet_priv *priv;
576 s32 err = 0;
577
578 if (!dev->of_node)
579 return -ENODEV;
580
581 ndev = alloc_etherdev(sizeof(struct nps_enet_priv));
582 if (!ndev)
583 return -ENOMEM;
584
585 platform_set_drvdata(pdev, ndev);
586 SET_NETDEV_DEV(ndev, dev);
587 priv = netdev_priv(ndev);
588
589 /* The EZ NET specific entries in the device structure. */
590 ndev->netdev_ops = &nps_netdev_ops;
591 ndev->watchdog_timeo = (400 * HZ / 1000);
592 /* FIXME :: no multicast support yet */
593 ndev->flags &= ~IFF_MULTICAST;
594
595 priv->regs_base = devm_platform_ioremap_resource(pdev, 0);
596 if (IS_ERR(priv->regs_base)) {
597 err = PTR_ERR(priv->regs_base);
598 goto out_netdev;
599 }
600 dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs_base);
601
602 /* set kernel MAC address to dev */
603 err = of_get_ethdev_address(dev->of_node, ndev);
604 if (err)
605 eth_hw_addr_random(ndev);
606
607 /* Get IRQ number */
608 priv->irq = platform_get_irq(pdev, 0);
609 if (priv->irq < 0) {
610 err = -ENODEV;
611 goto out_netdev;
612 }
613
614 netif_napi_add_weight(ndev, &priv->napi, nps_enet_poll,
615 NPS_ENET_NAPI_POLL_WEIGHT);
616
617 /* Register the driver. Should be the last thing in probe */
618 err = register_netdev(ndev);
619 if (err) {
620 dev_err(dev, "Failed to register ndev for %s, err = 0x%08x\n",
621 ndev->name, (s32)err);
622 goto out_netif_api;
623 }
624
625 dev_info(dev, "(rx/tx=%d)\n", priv->irq);
626 return 0;
627
628 out_netif_api:
629 netif_napi_del(&priv->napi);
630 out_netdev:
631 free_netdev(ndev);
632
633 return err;
634 }
635
nps_enet_remove(struct platform_device * pdev)636 static void nps_enet_remove(struct platform_device *pdev)
637 {
638 struct net_device *ndev = platform_get_drvdata(pdev);
639 struct nps_enet_priv *priv = netdev_priv(ndev);
640
641 unregister_netdev(ndev);
642 netif_napi_del(&priv->napi);
643 free_netdev(ndev);
644 }
645
646 static const struct of_device_id nps_enet_dt_ids[] = {
647 { .compatible = "ezchip,nps-mgt-enet" },
648 { /* Sentinel */ }
649 };
650 MODULE_DEVICE_TABLE(of, nps_enet_dt_ids);
651
652 static struct platform_driver nps_enet_driver = {
653 .probe = nps_enet_probe,
654 .remove_new = nps_enet_remove,
655 .driver = {
656 .name = DRV_NAME,
657 .of_match_table = nps_enet_dt_ids,
658 },
659 };
660
661 module_platform_driver(nps_enet_driver);
662
663 MODULE_AUTHOR("EZchip Semiconductor");
664 MODULE_DESCRIPTION("EZchip NPS Ethernet driver");
665 MODULE_LICENSE("GPL v2");
666