xref: /openbmc/linux/drivers/net/ethernet/ni/nixge.c (revision bdeeed09)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2016-2017, National Instruments Corp.
3  *
4  * Author: Moritz Fischer <mdf@kernel.org>
5  */
6 
7 #include <linux/etherdevice.h>
8 #include <linux/module.h>
9 #include <linux/netdevice.h>
10 #include <linux/of_address.h>
11 #include <linux/of_mdio.h>
12 #include <linux/of_net.h>
13 #include <linux/of_platform.h>
14 #include <linux/of_irq.h>
15 #include <linux/skbuff.h>
16 #include <linux/phy.h>
17 #include <linux/mii.h>
18 #include <linux/nvmem-consumer.h>
19 #include <linux/ethtool.h>
20 #include <linux/iopoll.h>
21 
22 #define TX_BD_NUM		64
23 #define RX_BD_NUM		128
24 
25 /* Axi DMA Register definitions */
26 #define XAXIDMA_TX_CR_OFFSET	0x00 /* Channel control */
27 #define XAXIDMA_TX_SR_OFFSET	0x04 /* Status */
28 #define XAXIDMA_TX_CDESC_OFFSET	0x08 /* Current descriptor pointer */
29 #define XAXIDMA_TX_TDESC_OFFSET	0x10 /* Tail descriptor pointer */
30 
31 #define XAXIDMA_RX_CR_OFFSET	0x30 /* Channel control */
32 #define XAXIDMA_RX_SR_OFFSET	0x34 /* Status */
33 #define XAXIDMA_RX_CDESC_OFFSET	0x38 /* Current descriptor pointer */
34 #define XAXIDMA_RX_TDESC_OFFSET	0x40 /* Tail descriptor pointer */
35 
36 #define XAXIDMA_CR_RUNSTOP_MASK	0x1 /* Start/stop DMA channel */
37 #define XAXIDMA_CR_RESET_MASK	0x4 /* Reset DMA engine */
38 
39 #define XAXIDMA_BD_CTRL_LENGTH_MASK	0x007FFFFF /* Requested len */
40 #define XAXIDMA_BD_CTRL_TXSOF_MASK	0x08000000 /* First tx packet */
41 #define XAXIDMA_BD_CTRL_TXEOF_MASK	0x04000000 /* Last tx packet */
42 #define XAXIDMA_BD_CTRL_ALL_MASK	0x0C000000 /* All control bits */
43 
44 #define XAXIDMA_DELAY_MASK		0xFF000000 /* Delay timeout counter */
45 #define XAXIDMA_COALESCE_MASK		0x00FF0000 /* Coalesce counter */
46 
47 #define XAXIDMA_DELAY_SHIFT		24
48 #define XAXIDMA_COALESCE_SHIFT		16
49 
50 #define XAXIDMA_IRQ_IOC_MASK		0x00001000 /* Completion intr */
51 #define XAXIDMA_IRQ_DELAY_MASK		0x00002000 /* Delay interrupt */
52 #define XAXIDMA_IRQ_ERROR_MASK		0x00004000 /* Error interrupt */
53 #define XAXIDMA_IRQ_ALL_MASK		0x00007000 /* All interrupts */
54 
55 /* Default TX/RX Threshold and waitbound values for SGDMA mode */
56 #define XAXIDMA_DFT_TX_THRESHOLD	24
57 #define XAXIDMA_DFT_TX_WAITBOUND	254
58 #define XAXIDMA_DFT_RX_THRESHOLD	24
59 #define XAXIDMA_DFT_RX_WAITBOUND	254
60 
61 #define XAXIDMA_BD_STS_ACTUAL_LEN_MASK	0x007FFFFF /* Actual len */
62 #define XAXIDMA_BD_STS_COMPLETE_MASK	0x80000000 /* Completed */
63 #define XAXIDMA_BD_STS_DEC_ERR_MASK	0x40000000 /* Decode error */
64 #define XAXIDMA_BD_STS_SLV_ERR_MASK	0x20000000 /* Slave error */
65 #define XAXIDMA_BD_STS_INT_ERR_MASK	0x10000000 /* Internal err */
66 #define XAXIDMA_BD_STS_ALL_ERR_MASK	0x70000000 /* All errors */
67 #define XAXIDMA_BD_STS_RXSOF_MASK	0x08000000 /* First rx pkt */
68 #define XAXIDMA_BD_STS_RXEOF_MASK	0x04000000 /* Last rx pkt */
69 #define XAXIDMA_BD_STS_ALL_MASK		0xFC000000 /* All status bits */
70 
71 #define NIXGE_REG_CTRL_OFFSET	0x4000
72 #define NIXGE_REG_INFO		0x00
73 #define NIXGE_REG_MAC_CTL	0x04
74 #define NIXGE_REG_PHY_CTL	0x08
75 #define NIXGE_REG_LED_CTL	0x0c
76 #define NIXGE_REG_MDIO_DATA	0x10
77 #define NIXGE_REG_MDIO_ADDR	0x14
78 #define NIXGE_REG_MDIO_OP	0x18
79 #define NIXGE_REG_MDIO_CTRL	0x1c
80 
81 #define NIXGE_ID_LED_CTL_EN	BIT(0)
82 #define NIXGE_ID_LED_CTL_VAL	BIT(1)
83 
84 #define NIXGE_MDIO_CLAUSE45	BIT(12)
85 #define NIXGE_MDIO_CLAUSE22	0
86 #define NIXGE_MDIO_OP(n)     (((n) & 0x3) << 10)
87 #define NIXGE_MDIO_OP_ADDRESS	0
88 #define NIXGE_MDIO_C45_WRITE	BIT(0)
89 #define NIXGE_MDIO_C45_READ	(BIT(1) | BIT(0))
90 #define NIXGE_MDIO_C22_WRITE	BIT(0)
91 #define NIXGE_MDIO_C22_READ	BIT(1)
92 #define NIXGE_MDIO_ADDR(n)   (((n) & 0x1f) << 5)
93 #define NIXGE_MDIO_MMD(n)    (((n) & 0x1f) << 0)
94 
95 #define NIXGE_REG_MAC_LSB	0x1000
96 #define NIXGE_REG_MAC_MSB	0x1004
97 
98 /* Packet size info */
99 #define NIXGE_HDR_SIZE		14 /* Size of Ethernet header */
100 #define NIXGE_TRL_SIZE		4 /* Size of Ethernet trailer (FCS) */
101 #define NIXGE_MTU		1500 /* Max MTU of an Ethernet frame */
102 #define NIXGE_JUMBO_MTU		9000 /* Max MTU of a jumbo Eth. frame */
103 
104 #define NIXGE_MAX_FRAME_SIZE	 (NIXGE_MTU + NIXGE_HDR_SIZE + NIXGE_TRL_SIZE)
105 #define NIXGE_MAX_JUMBO_FRAME_SIZE \
106 	(NIXGE_JUMBO_MTU + NIXGE_HDR_SIZE + NIXGE_TRL_SIZE)
107 
108 struct nixge_hw_dma_bd {
109 	u32 next;
110 	u32 reserved1;
111 	u32 phys;
112 	u32 reserved2;
113 	u32 reserved3;
114 	u32 reserved4;
115 	u32 cntrl;
116 	u32 status;
117 	u32 app0;
118 	u32 app1;
119 	u32 app2;
120 	u32 app3;
121 	u32 app4;
122 	u32 sw_id_offset;
123 	u32 reserved5;
124 	u32 reserved6;
125 };
126 
127 struct nixge_tx_skb {
128 	struct sk_buff *skb;
129 	dma_addr_t mapping;
130 	size_t size;
131 	bool mapped_as_page;
132 };
133 
134 struct nixge_priv {
135 	struct net_device *ndev;
136 	struct napi_struct napi;
137 	struct device *dev;
138 
139 	/* Connection to PHY device */
140 	struct device_node *phy_node;
141 	phy_interface_t		phy_mode;
142 
143 	int link;
144 	unsigned int speed;
145 	unsigned int duplex;
146 
147 	/* MDIO bus data */
148 	struct mii_bus *mii_bus;	/* MII bus reference */
149 
150 	/* IO registers, dma functions and IRQs */
151 	void __iomem *ctrl_regs;
152 	void __iomem *dma_regs;
153 
154 	struct tasklet_struct dma_err_tasklet;
155 
156 	int tx_irq;
157 	int rx_irq;
158 	u32 last_link;
159 
160 	/* Buffer descriptors */
161 	struct nixge_hw_dma_bd *tx_bd_v;
162 	struct nixge_tx_skb *tx_skb;
163 	dma_addr_t tx_bd_p;
164 
165 	struct nixge_hw_dma_bd *rx_bd_v;
166 	dma_addr_t rx_bd_p;
167 	u32 tx_bd_ci;
168 	u32 tx_bd_tail;
169 	u32 rx_bd_ci;
170 
171 	u32 coalesce_count_rx;
172 	u32 coalesce_count_tx;
173 };
174 
175 static void nixge_dma_write_reg(struct nixge_priv *priv, off_t offset, u32 val)
176 {
177 	writel(val, priv->dma_regs + offset);
178 }
179 
180 static u32 nixge_dma_read_reg(const struct nixge_priv *priv, off_t offset)
181 {
182 	return readl(priv->dma_regs + offset);
183 }
184 
185 static void nixge_ctrl_write_reg(struct nixge_priv *priv, off_t offset, u32 val)
186 {
187 	writel(val, priv->ctrl_regs + offset);
188 }
189 
190 static u32 nixge_ctrl_read_reg(struct nixge_priv *priv, off_t offset)
191 {
192 	return readl(priv->ctrl_regs + offset);
193 }
194 
195 #define nixge_ctrl_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
196 	readl_poll_timeout((priv)->ctrl_regs + (addr), (val), (cond), \
197 			   (sleep_us), (timeout_us))
198 
199 #define nixge_dma_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
200 	readl_poll_timeout((priv)->dma_regs + (addr), (val), (cond), \
201 			   (sleep_us), (timeout_us))
202 
203 static void nixge_hw_dma_bd_release(struct net_device *ndev)
204 {
205 	struct nixge_priv *priv = netdev_priv(ndev);
206 	int i;
207 
208 	for (i = 0; i < RX_BD_NUM; i++) {
209 		dma_unmap_single(ndev->dev.parent, priv->rx_bd_v[i].phys,
210 				 NIXGE_MAX_JUMBO_FRAME_SIZE, DMA_FROM_DEVICE);
211 		dev_kfree_skb((struct sk_buff *)
212 			      (priv->rx_bd_v[i].sw_id_offset));
213 	}
214 
215 	if (priv->rx_bd_v)
216 		dma_free_coherent(ndev->dev.parent,
217 				  sizeof(*priv->rx_bd_v) * RX_BD_NUM,
218 				  priv->rx_bd_v,
219 				  priv->rx_bd_p);
220 
221 	if (priv->tx_skb)
222 		devm_kfree(ndev->dev.parent, priv->tx_skb);
223 
224 	if (priv->tx_bd_v)
225 		dma_free_coherent(ndev->dev.parent,
226 				  sizeof(*priv->tx_bd_v) * TX_BD_NUM,
227 				  priv->tx_bd_v,
228 				  priv->tx_bd_p);
229 }
230 
231 static int nixge_hw_dma_bd_init(struct net_device *ndev)
232 {
233 	struct nixge_priv *priv = netdev_priv(ndev);
234 	struct sk_buff *skb;
235 	u32 cr;
236 	int i;
237 
238 	/* Reset the indexes which are used for accessing the BDs */
239 	priv->tx_bd_ci = 0;
240 	priv->tx_bd_tail = 0;
241 	priv->rx_bd_ci = 0;
242 
243 	/* Allocate the Tx and Rx buffer descriptors. */
244 	priv->tx_bd_v = dma_zalloc_coherent(ndev->dev.parent,
245 					    sizeof(*priv->tx_bd_v) * TX_BD_NUM,
246 					    &priv->tx_bd_p, GFP_KERNEL);
247 	if (!priv->tx_bd_v)
248 		goto out;
249 
250 	priv->tx_skb = devm_kzalloc(ndev->dev.parent,
251 				    sizeof(*priv->tx_skb) *
252 				    TX_BD_NUM,
253 				    GFP_KERNEL);
254 	if (!priv->tx_skb)
255 		goto out;
256 
257 	priv->rx_bd_v = dma_zalloc_coherent(ndev->dev.parent,
258 					    sizeof(*priv->rx_bd_v) * RX_BD_NUM,
259 					    &priv->rx_bd_p, GFP_KERNEL);
260 	if (!priv->rx_bd_v)
261 		goto out;
262 
263 	for (i = 0; i < TX_BD_NUM; i++) {
264 		priv->tx_bd_v[i].next = priv->tx_bd_p +
265 				      sizeof(*priv->tx_bd_v) *
266 				      ((i + 1) % TX_BD_NUM);
267 	}
268 
269 	for (i = 0; i < RX_BD_NUM; i++) {
270 		priv->rx_bd_v[i].next = priv->rx_bd_p +
271 				      sizeof(*priv->rx_bd_v) *
272 				      ((i + 1) % RX_BD_NUM);
273 
274 		skb = netdev_alloc_skb_ip_align(ndev,
275 						NIXGE_MAX_JUMBO_FRAME_SIZE);
276 		if (!skb)
277 			goto out;
278 
279 		priv->rx_bd_v[i].sw_id_offset = (u32)skb;
280 		priv->rx_bd_v[i].phys =
281 			dma_map_single(ndev->dev.parent,
282 				       skb->data,
283 				       NIXGE_MAX_JUMBO_FRAME_SIZE,
284 				       DMA_FROM_DEVICE);
285 		priv->rx_bd_v[i].cntrl = NIXGE_MAX_JUMBO_FRAME_SIZE;
286 	}
287 
288 	/* Start updating the Rx channel control register */
289 	cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
290 	/* Update the interrupt coalesce count */
291 	cr = ((cr & ~XAXIDMA_COALESCE_MASK) |
292 	      ((priv->coalesce_count_rx) << XAXIDMA_COALESCE_SHIFT));
293 	/* Update the delay timer count */
294 	cr = ((cr & ~XAXIDMA_DELAY_MASK) |
295 	      (XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
296 	/* Enable coalesce, delay timer and error interrupts */
297 	cr |= XAXIDMA_IRQ_ALL_MASK;
298 	/* Write to the Rx channel control register */
299 	nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
300 
301 	/* Start updating the Tx channel control register */
302 	cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
303 	/* Update the interrupt coalesce count */
304 	cr = (((cr & ~XAXIDMA_COALESCE_MASK)) |
305 	      ((priv->coalesce_count_tx) << XAXIDMA_COALESCE_SHIFT));
306 	/* Update the delay timer count */
307 	cr = (((cr & ~XAXIDMA_DELAY_MASK)) |
308 	      (XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
309 	/* Enable coalesce, delay timer and error interrupts */
310 	cr |= XAXIDMA_IRQ_ALL_MASK;
311 	/* Write to the Tx channel control register */
312 	nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET, cr);
313 
314 	/* Populate the tail pointer and bring the Rx Axi DMA engine out of
315 	 * halted state. This will make the Rx side ready for reception.
316 	 */
317 	nixge_dma_write_reg(priv, XAXIDMA_RX_CDESC_OFFSET, priv->rx_bd_p);
318 	cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
319 	nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET,
320 			    cr | XAXIDMA_CR_RUNSTOP_MASK);
321 	nixge_dma_write_reg(priv, XAXIDMA_RX_TDESC_OFFSET, priv->rx_bd_p +
322 			    (sizeof(*priv->rx_bd_v) * (RX_BD_NUM - 1)));
323 
324 	/* Write to the RS (Run-stop) bit in the Tx channel control register.
325 	 * Tx channel is now ready to run. But only after we write to the
326 	 * tail pointer register that the Tx channel will start transmitting.
327 	 */
328 	nixge_dma_write_reg(priv, XAXIDMA_TX_CDESC_OFFSET, priv->tx_bd_p);
329 	cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
330 	nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET,
331 			    cr | XAXIDMA_CR_RUNSTOP_MASK);
332 
333 	return 0;
334 out:
335 	nixge_hw_dma_bd_release(ndev);
336 	return -ENOMEM;
337 }
338 
339 static void __nixge_device_reset(struct nixge_priv *priv, off_t offset)
340 {
341 	u32 status;
342 	int err;
343 
344 	/* Reset Axi DMA. This would reset NIXGE Ethernet core as well.
345 	 * The reset process of Axi DMA takes a while to complete as all
346 	 * pending commands/transfers will be flushed or completed during
347 	 * this reset process.
348 	 */
349 	nixge_dma_write_reg(priv, offset, XAXIDMA_CR_RESET_MASK);
350 	err = nixge_dma_poll_timeout(priv, offset, status,
351 				     !(status & XAXIDMA_CR_RESET_MASK), 10,
352 				     1000);
353 	if (err)
354 		netdev_err(priv->ndev, "%s: DMA reset timeout!\n", __func__);
355 }
356 
357 static void nixge_device_reset(struct net_device *ndev)
358 {
359 	struct nixge_priv *priv = netdev_priv(ndev);
360 
361 	__nixge_device_reset(priv, XAXIDMA_TX_CR_OFFSET);
362 	__nixge_device_reset(priv, XAXIDMA_RX_CR_OFFSET);
363 
364 	if (nixge_hw_dma_bd_init(ndev))
365 		netdev_err(ndev, "%s: descriptor allocation failed\n",
366 			   __func__);
367 
368 	netif_trans_update(ndev);
369 }
370 
371 static void nixge_handle_link_change(struct net_device *ndev)
372 {
373 	struct nixge_priv *priv = netdev_priv(ndev);
374 	struct phy_device *phydev = ndev->phydev;
375 
376 	if (phydev->link != priv->link || phydev->speed != priv->speed ||
377 	    phydev->duplex != priv->duplex) {
378 		priv->link = phydev->link;
379 		priv->speed = phydev->speed;
380 		priv->duplex = phydev->duplex;
381 		phy_print_status(phydev);
382 	}
383 }
384 
385 static void nixge_tx_skb_unmap(struct nixge_priv *priv,
386 			       struct nixge_tx_skb *tx_skb)
387 {
388 	if (tx_skb->mapping) {
389 		if (tx_skb->mapped_as_page)
390 			dma_unmap_page(priv->ndev->dev.parent, tx_skb->mapping,
391 				       tx_skb->size, DMA_TO_DEVICE);
392 		else
393 			dma_unmap_single(priv->ndev->dev.parent,
394 					 tx_skb->mapping,
395 					 tx_skb->size, DMA_TO_DEVICE);
396 		tx_skb->mapping = 0;
397 	}
398 
399 	if (tx_skb->skb) {
400 		dev_kfree_skb_any(tx_skb->skb);
401 		tx_skb->skb = NULL;
402 	}
403 }
404 
405 static void nixge_start_xmit_done(struct net_device *ndev)
406 {
407 	struct nixge_priv *priv = netdev_priv(ndev);
408 	struct nixge_hw_dma_bd *cur_p;
409 	struct nixge_tx_skb *tx_skb;
410 	unsigned int status = 0;
411 	u32 packets = 0;
412 	u32 size = 0;
413 
414 	cur_p = &priv->tx_bd_v[priv->tx_bd_ci];
415 	tx_skb = &priv->tx_skb[priv->tx_bd_ci];
416 
417 	status = cur_p->status;
418 
419 	while (status & XAXIDMA_BD_STS_COMPLETE_MASK) {
420 		nixge_tx_skb_unmap(priv, tx_skb);
421 		cur_p->status = 0;
422 
423 		size += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
424 		packets++;
425 
426 		++priv->tx_bd_ci;
427 		priv->tx_bd_ci %= TX_BD_NUM;
428 		cur_p = &priv->tx_bd_v[priv->tx_bd_ci];
429 		tx_skb = &priv->tx_skb[priv->tx_bd_ci];
430 		status = cur_p->status;
431 	}
432 
433 	ndev->stats.tx_packets += packets;
434 	ndev->stats.tx_bytes += size;
435 
436 	if (packets)
437 		netif_wake_queue(ndev);
438 }
439 
440 static int nixge_check_tx_bd_space(struct nixge_priv *priv,
441 				   int num_frag)
442 {
443 	struct nixge_hw_dma_bd *cur_p;
444 
445 	cur_p = &priv->tx_bd_v[(priv->tx_bd_tail + num_frag) % TX_BD_NUM];
446 	if (cur_p->status & XAXIDMA_BD_STS_ALL_MASK)
447 		return NETDEV_TX_BUSY;
448 	return 0;
449 }
450 
451 static int nixge_start_xmit(struct sk_buff *skb, struct net_device *ndev)
452 {
453 	struct nixge_priv *priv = netdev_priv(ndev);
454 	struct nixge_hw_dma_bd *cur_p;
455 	struct nixge_tx_skb *tx_skb;
456 	dma_addr_t tail_p;
457 	skb_frag_t *frag;
458 	u32 num_frag;
459 	u32 ii;
460 
461 	num_frag = skb_shinfo(skb)->nr_frags;
462 	cur_p = &priv->tx_bd_v[priv->tx_bd_tail];
463 	tx_skb = &priv->tx_skb[priv->tx_bd_tail];
464 
465 	if (nixge_check_tx_bd_space(priv, num_frag)) {
466 		if (!netif_queue_stopped(ndev))
467 			netif_stop_queue(ndev);
468 		return NETDEV_TX_OK;
469 	}
470 
471 	cur_p->phys = dma_map_single(ndev->dev.parent, skb->data,
472 				     skb_headlen(skb), DMA_TO_DEVICE);
473 	if (dma_mapping_error(ndev->dev.parent, cur_p->phys))
474 		goto drop;
475 
476 	cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;
477 
478 	tx_skb->skb = NULL;
479 	tx_skb->mapping = cur_p->phys;
480 	tx_skb->size = skb_headlen(skb);
481 	tx_skb->mapped_as_page = false;
482 
483 	for (ii = 0; ii < num_frag; ii++) {
484 		++priv->tx_bd_tail;
485 		priv->tx_bd_tail %= TX_BD_NUM;
486 		cur_p = &priv->tx_bd_v[priv->tx_bd_tail];
487 		tx_skb = &priv->tx_skb[priv->tx_bd_tail];
488 		frag = &skb_shinfo(skb)->frags[ii];
489 
490 		cur_p->phys = skb_frag_dma_map(ndev->dev.parent, frag, 0,
491 					       skb_frag_size(frag),
492 					       DMA_TO_DEVICE);
493 		if (dma_mapping_error(ndev->dev.parent, cur_p->phys))
494 			goto frag_err;
495 
496 		cur_p->cntrl = skb_frag_size(frag);
497 
498 		tx_skb->skb = NULL;
499 		tx_skb->mapping = cur_p->phys;
500 		tx_skb->size = skb_frag_size(frag);
501 		tx_skb->mapped_as_page = true;
502 	}
503 
504 	/* last buffer of the frame */
505 	tx_skb->skb = skb;
506 
507 	cur_p->cntrl |= XAXIDMA_BD_CTRL_TXEOF_MASK;
508 	cur_p->app4 = (unsigned long)skb;
509 
510 	tail_p = priv->tx_bd_p + sizeof(*priv->tx_bd_v) * priv->tx_bd_tail;
511 	/* Start the transfer */
512 	nixge_dma_write_reg(priv, XAXIDMA_TX_TDESC_OFFSET, tail_p);
513 	++priv->tx_bd_tail;
514 	priv->tx_bd_tail %= TX_BD_NUM;
515 
516 	return NETDEV_TX_OK;
517 frag_err:
518 	for (; ii > 0; ii--) {
519 		if (priv->tx_bd_tail)
520 			priv->tx_bd_tail--;
521 		else
522 			priv->tx_bd_tail = TX_BD_NUM - 1;
523 
524 		tx_skb = &priv->tx_skb[priv->tx_bd_tail];
525 		nixge_tx_skb_unmap(priv, tx_skb);
526 
527 		cur_p = &priv->tx_bd_v[priv->tx_bd_tail];
528 		cur_p->status = 0;
529 	}
530 	dma_unmap_single(priv->ndev->dev.parent,
531 			 tx_skb->mapping,
532 			 tx_skb->size, DMA_TO_DEVICE);
533 drop:
534 	ndev->stats.tx_dropped++;
535 	return NETDEV_TX_OK;
536 }
537 
538 static int nixge_recv(struct net_device *ndev, int budget)
539 {
540 	struct nixge_priv *priv = netdev_priv(ndev);
541 	struct sk_buff *skb, *new_skb;
542 	struct nixge_hw_dma_bd *cur_p;
543 	dma_addr_t tail_p = 0;
544 	u32 packets = 0;
545 	u32 length = 0;
546 	u32 size = 0;
547 
548 	cur_p = &priv->rx_bd_v[priv->rx_bd_ci];
549 
550 	while ((cur_p->status & XAXIDMA_BD_STS_COMPLETE_MASK &&
551 		budget > packets)) {
552 		tail_p = priv->rx_bd_p + sizeof(*priv->rx_bd_v) *
553 			 priv->rx_bd_ci;
554 
555 		skb = (struct sk_buff *)(cur_p->sw_id_offset);
556 
557 		length = cur_p->status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
558 		if (length > NIXGE_MAX_JUMBO_FRAME_SIZE)
559 			length = NIXGE_MAX_JUMBO_FRAME_SIZE;
560 
561 		dma_unmap_single(ndev->dev.parent, cur_p->phys,
562 				 NIXGE_MAX_JUMBO_FRAME_SIZE,
563 				 DMA_FROM_DEVICE);
564 
565 		skb_put(skb, length);
566 
567 		skb->protocol = eth_type_trans(skb, ndev);
568 		skb_checksum_none_assert(skb);
569 
570 		/* For now mark them as CHECKSUM_NONE since
571 		 * we don't have offload capabilities
572 		 */
573 		skb->ip_summed = CHECKSUM_NONE;
574 
575 		napi_gro_receive(&priv->napi, skb);
576 
577 		size += length;
578 		packets++;
579 
580 		new_skb = netdev_alloc_skb_ip_align(ndev,
581 						    NIXGE_MAX_JUMBO_FRAME_SIZE);
582 		if (!new_skb)
583 			return packets;
584 
585 		cur_p->phys = dma_map_single(ndev->dev.parent, new_skb->data,
586 					     NIXGE_MAX_JUMBO_FRAME_SIZE,
587 					     DMA_FROM_DEVICE);
588 		if (dma_mapping_error(ndev->dev.parent, cur_p->phys)) {
589 			/* FIXME: bail out and clean up */
590 			netdev_err(ndev, "Failed to map ...\n");
591 		}
592 		cur_p->cntrl = NIXGE_MAX_JUMBO_FRAME_SIZE;
593 		cur_p->status = 0;
594 		cur_p->sw_id_offset = (u32)new_skb;
595 
596 		++priv->rx_bd_ci;
597 		priv->rx_bd_ci %= RX_BD_NUM;
598 		cur_p = &priv->rx_bd_v[priv->rx_bd_ci];
599 	}
600 
601 	ndev->stats.rx_packets += packets;
602 	ndev->stats.rx_bytes += size;
603 
604 	if (tail_p)
605 		nixge_dma_write_reg(priv, XAXIDMA_RX_TDESC_OFFSET, tail_p);
606 
607 	return packets;
608 }
609 
610 static int nixge_poll(struct napi_struct *napi, int budget)
611 {
612 	struct nixge_priv *priv = container_of(napi, struct nixge_priv, napi);
613 	int work_done;
614 	u32 status, cr;
615 
616 	work_done = 0;
617 
618 	work_done = nixge_recv(priv->ndev, budget);
619 	if (work_done < budget) {
620 		napi_complete_done(napi, work_done);
621 		status = nixge_dma_read_reg(priv, XAXIDMA_RX_SR_OFFSET);
622 
623 		if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) {
624 			/* If there's more, reschedule, but clear */
625 			nixge_dma_write_reg(priv, XAXIDMA_RX_SR_OFFSET, status);
626 			napi_reschedule(napi);
627 		} else {
628 			/* if not, turn on RX IRQs again ... */
629 			cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
630 			cr |= (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
631 			nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
632 		}
633 	}
634 
635 	return work_done;
636 }
637 
638 static irqreturn_t nixge_tx_irq(int irq, void *_ndev)
639 {
640 	struct nixge_priv *priv = netdev_priv(_ndev);
641 	struct net_device *ndev = _ndev;
642 	unsigned int status;
643 	u32 cr;
644 
645 	status = nixge_dma_read_reg(priv, XAXIDMA_TX_SR_OFFSET);
646 	if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) {
647 		nixge_dma_write_reg(priv, XAXIDMA_TX_SR_OFFSET, status);
648 		nixge_start_xmit_done(priv->ndev);
649 		goto out;
650 	}
651 	if (!(status & XAXIDMA_IRQ_ALL_MASK)) {
652 		netdev_err(ndev, "No interrupts asserted in Tx path\n");
653 		return IRQ_NONE;
654 	}
655 	if (status & XAXIDMA_IRQ_ERROR_MASK) {
656 		netdev_err(ndev, "DMA Tx error 0x%x\n", status);
657 		netdev_err(ndev, "Current BD is at: 0x%x\n",
658 			   (priv->tx_bd_v[priv->tx_bd_ci]).phys);
659 
660 		cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
661 		/* Disable coalesce, delay timer and error interrupts */
662 		cr &= (~XAXIDMA_IRQ_ALL_MASK);
663 		/* Write to the Tx channel control register */
664 		nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET, cr);
665 
666 		cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
667 		/* Disable coalesce, delay timer and error interrupts */
668 		cr &= (~XAXIDMA_IRQ_ALL_MASK);
669 		/* Write to the Rx channel control register */
670 		nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
671 
672 		tasklet_schedule(&priv->dma_err_tasklet);
673 		nixge_dma_write_reg(priv, XAXIDMA_TX_SR_OFFSET, status);
674 	}
675 out:
676 	return IRQ_HANDLED;
677 }
678 
679 static irqreturn_t nixge_rx_irq(int irq, void *_ndev)
680 {
681 	struct nixge_priv *priv = netdev_priv(_ndev);
682 	struct net_device *ndev = _ndev;
683 	unsigned int status;
684 	u32 cr;
685 
686 	status = nixge_dma_read_reg(priv, XAXIDMA_RX_SR_OFFSET);
687 	if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) {
688 		/* Turn of IRQs because NAPI */
689 		nixge_dma_write_reg(priv, XAXIDMA_RX_SR_OFFSET, status);
690 		cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
691 		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
692 		nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
693 
694 		if (napi_schedule_prep(&priv->napi))
695 			__napi_schedule(&priv->napi);
696 		goto out;
697 	}
698 	if (!(status & XAXIDMA_IRQ_ALL_MASK)) {
699 		netdev_err(ndev, "No interrupts asserted in Rx path\n");
700 		return IRQ_NONE;
701 	}
702 	if (status & XAXIDMA_IRQ_ERROR_MASK) {
703 		netdev_err(ndev, "DMA Rx error 0x%x\n", status);
704 		netdev_err(ndev, "Current BD is at: 0x%x\n",
705 			   (priv->rx_bd_v[priv->rx_bd_ci]).phys);
706 
707 		cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
708 		/* Disable coalesce, delay timer and error interrupts */
709 		cr &= (~XAXIDMA_IRQ_ALL_MASK);
710 		/* Finally write to the Tx channel control register */
711 		nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET, cr);
712 
713 		cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
714 		/* Disable coalesce, delay timer and error interrupts */
715 		cr &= (~XAXIDMA_IRQ_ALL_MASK);
716 		/* write to the Rx channel control register */
717 		nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET, cr);
718 
719 		tasklet_schedule(&priv->dma_err_tasklet);
720 		nixge_dma_write_reg(priv, XAXIDMA_RX_SR_OFFSET, status);
721 	}
722 out:
723 	return IRQ_HANDLED;
724 }
725 
726 static void nixge_dma_err_handler(unsigned long data)
727 {
728 	struct nixge_priv *lp = (struct nixge_priv *)data;
729 	struct nixge_hw_dma_bd *cur_p;
730 	struct nixge_tx_skb *tx_skb;
731 	u32 cr, i;
732 
733 	__nixge_device_reset(lp, XAXIDMA_TX_CR_OFFSET);
734 	__nixge_device_reset(lp, XAXIDMA_RX_CR_OFFSET);
735 
736 	for (i = 0; i < TX_BD_NUM; i++) {
737 		cur_p = &lp->tx_bd_v[i];
738 		tx_skb = &lp->tx_skb[i];
739 		nixge_tx_skb_unmap(lp, tx_skb);
740 
741 		cur_p->phys = 0;
742 		cur_p->cntrl = 0;
743 		cur_p->status = 0;
744 		cur_p->app0 = 0;
745 		cur_p->app1 = 0;
746 		cur_p->app2 = 0;
747 		cur_p->app3 = 0;
748 		cur_p->app4 = 0;
749 		cur_p->sw_id_offset = 0;
750 	}
751 
752 	for (i = 0; i < RX_BD_NUM; i++) {
753 		cur_p = &lp->rx_bd_v[i];
754 		cur_p->status = 0;
755 		cur_p->app0 = 0;
756 		cur_p->app1 = 0;
757 		cur_p->app2 = 0;
758 		cur_p->app3 = 0;
759 		cur_p->app4 = 0;
760 	}
761 
762 	lp->tx_bd_ci = 0;
763 	lp->tx_bd_tail = 0;
764 	lp->rx_bd_ci = 0;
765 
766 	/* Start updating the Rx channel control register */
767 	cr = nixge_dma_read_reg(lp, XAXIDMA_RX_CR_OFFSET);
768 	/* Update the interrupt coalesce count */
769 	cr = ((cr & ~XAXIDMA_COALESCE_MASK) |
770 	      (XAXIDMA_DFT_RX_THRESHOLD << XAXIDMA_COALESCE_SHIFT));
771 	/* Update the delay timer count */
772 	cr = ((cr & ~XAXIDMA_DELAY_MASK) |
773 	      (XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
774 	/* Enable coalesce, delay timer and error interrupts */
775 	cr |= XAXIDMA_IRQ_ALL_MASK;
776 	/* Finally write to the Rx channel control register */
777 	nixge_dma_write_reg(lp, XAXIDMA_RX_CR_OFFSET, cr);
778 
779 	/* Start updating the Tx channel control register */
780 	cr = nixge_dma_read_reg(lp, XAXIDMA_TX_CR_OFFSET);
781 	/* Update the interrupt coalesce count */
782 	cr = (((cr & ~XAXIDMA_COALESCE_MASK)) |
783 	      (XAXIDMA_DFT_TX_THRESHOLD << XAXIDMA_COALESCE_SHIFT));
784 	/* Update the delay timer count */
785 	cr = (((cr & ~XAXIDMA_DELAY_MASK)) |
786 	      (XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
787 	/* Enable coalesce, delay timer and error interrupts */
788 	cr |= XAXIDMA_IRQ_ALL_MASK;
789 	/* Finally write to the Tx channel control register */
790 	nixge_dma_write_reg(lp, XAXIDMA_TX_CR_OFFSET, cr);
791 
792 	/* Populate the tail pointer and bring the Rx Axi DMA engine out of
793 	 * halted state. This will make the Rx side ready for reception.
794 	 */
795 	nixge_dma_write_reg(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p);
796 	cr = nixge_dma_read_reg(lp, XAXIDMA_RX_CR_OFFSET);
797 	nixge_dma_write_reg(lp, XAXIDMA_RX_CR_OFFSET,
798 			    cr | XAXIDMA_CR_RUNSTOP_MASK);
799 	nixge_dma_write_reg(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p +
800 			    (sizeof(*lp->rx_bd_v) * (RX_BD_NUM - 1)));
801 
802 	/* Write to the RS (Run-stop) bit in the Tx channel control register.
803 	 * Tx channel is now ready to run. But only after we write to the
804 	 * tail pointer register that the Tx channel will start transmitting
805 	 */
806 	nixge_dma_write_reg(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p);
807 	cr = nixge_dma_read_reg(lp, XAXIDMA_TX_CR_OFFSET);
808 	nixge_dma_write_reg(lp, XAXIDMA_TX_CR_OFFSET,
809 			    cr | XAXIDMA_CR_RUNSTOP_MASK);
810 }
811 
812 static int nixge_open(struct net_device *ndev)
813 {
814 	struct nixge_priv *priv = netdev_priv(ndev);
815 	struct phy_device *phy;
816 	int ret;
817 
818 	nixge_device_reset(ndev);
819 
820 	phy = of_phy_connect(ndev, priv->phy_node,
821 			     &nixge_handle_link_change, 0, priv->phy_mode);
822 	if (!phy)
823 		return -ENODEV;
824 
825 	phy_start(phy);
826 
827 	/* Enable tasklets for Axi DMA error handling */
828 	tasklet_init(&priv->dma_err_tasklet, nixge_dma_err_handler,
829 		     (unsigned long)priv);
830 
831 	napi_enable(&priv->napi);
832 
833 	/* Enable interrupts for Axi DMA Tx */
834 	ret = request_irq(priv->tx_irq, nixge_tx_irq, 0, ndev->name, ndev);
835 	if (ret)
836 		goto err_tx_irq;
837 	/* Enable interrupts for Axi DMA Rx */
838 	ret = request_irq(priv->rx_irq, nixge_rx_irq, 0, ndev->name, ndev);
839 	if (ret)
840 		goto err_rx_irq;
841 
842 	netif_start_queue(ndev);
843 
844 	return 0;
845 
846 err_rx_irq:
847 	free_irq(priv->tx_irq, ndev);
848 err_tx_irq:
849 	phy_stop(phy);
850 	phy_disconnect(phy);
851 	tasklet_kill(&priv->dma_err_tasklet);
852 	netdev_err(ndev, "request_irq() failed\n");
853 	return ret;
854 }
855 
856 static int nixge_stop(struct net_device *ndev)
857 {
858 	struct nixge_priv *priv = netdev_priv(ndev);
859 	u32 cr;
860 
861 	netif_stop_queue(ndev);
862 	napi_disable(&priv->napi);
863 
864 	if (ndev->phydev) {
865 		phy_stop(ndev->phydev);
866 		phy_disconnect(ndev->phydev);
867 	}
868 
869 	cr = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
870 	nixge_dma_write_reg(priv, XAXIDMA_RX_CR_OFFSET,
871 			    cr & (~XAXIDMA_CR_RUNSTOP_MASK));
872 	cr = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
873 	nixge_dma_write_reg(priv, XAXIDMA_TX_CR_OFFSET,
874 			    cr & (~XAXIDMA_CR_RUNSTOP_MASK));
875 
876 	tasklet_kill(&priv->dma_err_tasklet);
877 
878 	free_irq(priv->tx_irq, ndev);
879 	free_irq(priv->rx_irq, ndev);
880 
881 	nixge_hw_dma_bd_release(ndev);
882 
883 	return 0;
884 }
885 
886 static int nixge_change_mtu(struct net_device *ndev, int new_mtu)
887 {
888 	if (netif_running(ndev))
889 		return -EBUSY;
890 
891 	if ((new_mtu + NIXGE_HDR_SIZE + NIXGE_TRL_SIZE) >
892 	     NIXGE_MAX_JUMBO_FRAME_SIZE)
893 		return -EINVAL;
894 
895 	ndev->mtu = new_mtu;
896 
897 	return 0;
898 }
899 
900 static s32 __nixge_hw_set_mac_address(struct net_device *ndev)
901 {
902 	struct nixge_priv *priv = netdev_priv(ndev);
903 
904 	nixge_ctrl_write_reg(priv, NIXGE_REG_MAC_LSB,
905 			     (ndev->dev_addr[2]) << 24 |
906 			     (ndev->dev_addr[3] << 16) |
907 			     (ndev->dev_addr[4] << 8) |
908 			     (ndev->dev_addr[5] << 0));
909 
910 	nixge_ctrl_write_reg(priv, NIXGE_REG_MAC_MSB,
911 			     (ndev->dev_addr[1] | (ndev->dev_addr[0] << 8)));
912 
913 	return 0;
914 }
915 
916 static int nixge_net_set_mac_address(struct net_device *ndev, void *p)
917 {
918 	int err;
919 
920 	err = eth_mac_addr(ndev, p);
921 	if (!err)
922 		__nixge_hw_set_mac_address(ndev);
923 
924 	return err;
925 }
926 
927 static const struct net_device_ops nixge_netdev_ops = {
928 	.ndo_open = nixge_open,
929 	.ndo_stop = nixge_stop,
930 	.ndo_start_xmit = nixge_start_xmit,
931 	.ndo_change_mtu	= nixge_change_mtu,
932 	.ndo_set_mac_address = nixge_net_set_mac_address,
933 	.ndo_validate_addr = eth_validate_addr,
934 };
935 
936 static void nixge_ethtools_get_drvinfo(struct net_device *ndev,
937 				       struct ethtool_drvinfo *ed)
938 {
939 	strlcpy(ed->driver, "nixge", sizeof(ed->driver));
940 	strlcpy(ed->bus_info, "platform", sizeof(ed->driver));
941 }
942 
943 static int nixge_ethtools_get_coalesce(struct net_device *ndev,
944 				       struct ethtool_coalesce *ecoalesce)
945 {
946 	struct nixge_priv *priv = netdev_priv(ndev);
947 	u32 regval = 0;
948 
949 	regval = nixge_dma_read_reg(priv, XAXIDMA_RX_CR_OFFSET);
950 	ecoalesce->rx_max_coalesced_frames = (regval & XAXIDMA_COALESCE_MASK)
951 					     >> XAXIDMA_COALESCE_SHIFT;
952 	regval = nixge_dma_read_reg(priv, XAXIDMA_TX_CR_OFFSET);
953 	ecoalesce->tx_max_coalesced_frames = (regval & XAXIDMA_COALESCE_MASK)
954 					     >> XAXIDMA_COALESCE_SHIFT;
955 	return 0;
956 }
957 
958 static int nixge_ethtools_set_coalesce(struct net_device *ndev,
959 				       struct ethtool_coalesce *ecoalesce)
960 {
961 	struct nixge_priv *priv = netdev_priv(ndev);
962 
963 	if (netif_running(ndev)) {
964 		netdev_err(ndev,
965 			   "Please stop netif before applying configuration\n");
966 		return -EBUSY;
967 	}
968 
969 	if (ecoalesce->rx_coalesce_usecs ||
970 	    ecoalesce->rx_coalesce_usecs_irq ||
971 	    ecoalesce->rx_max_coalesced_frames_irq ||
972 	    ecoalesce->tx_coalesce_usecs ||
973 	    ecoalesce->tx_coalesce_usecs_irq ||
974 	    ecoalesce->tx_max_coalesced_frames_irq ||
975 	    ecoalesce->stats_block_coalesce_usecs ||
976 	    ecoalesce->use_adaptive_rx_coalesce ||
977 	    ecoalesce->use_adaptive_tx_coalesce ||
978 	    ecoalesce->pkt_rate_low ||
979 	    ecoalesce->rx_coalesce_usecs_low ||
980 	    ecoalesce->rx_max_coalesced_frames_low ||
981 	    ecoalesce->tx_coalesce_usecs_low ||
982 	    ecoalesce->tx_max_coalesced_frames_low ||
983 	    ecoalesce->pkt_rate_high ||
984 	    ecoalesce->rx_coalesce_usecs_high ||
985 	    ecoalesce->rx_max_coalesced_frames_high ||
986 	    ecoalesce->tx_coalesce_usecs_high ||
987 	    ecoalesce->tx_max_coalesced_frames_high ||
988 	    ecoalesce->rate_sample_interval)
989 		return -EOPNOTSUPP;
990 	if (ecoalesce->rx_max_coalesced_frames)
991 		priv->coalesce_count_rx = ecoalesce->rx_max_coalesced_frames;
992 	if (ecoalesce->tx_max_coalesced_frames)
993 		priv->coalesce_count_tx = ecoalesce->tx_max_coalesced_frames;
994 
995 	return 0;
996 }
997 
998 static int nixge_ethtools_set_phys_id(struct net_device *ndev,
999 				      enum ethtool_phys_id_state state)
1000 {
1001 	struct nixge_priv *priv = netdev_priv(ndev);
1002 	u32 ctrl;
1003 
1004 	ctrl = nixge_ctrl_read_reg(priv, NIXGE_REG_LED_CTL);
1005 	switch (state) {
1006 	case ETHTOOL_ID_ACTIVE:
1007 		ctrl |= NIXGE_ID_LED_CTL_EN;
1008 		/* Enable identification LED override*/
1009 		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
1010 		return 2;
1011 
1012 	case ETHTOOL_ID_ON:
1013 		ctrl |= NIXGE_ID_LED_CTL_VAL;
1014 		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
1015 		break;
1016 
1017 	case ETHTOOL_ID_OFF:
1018 		ctrl &= ~NIXGE_ID_LED_CTL_VAL;
1019 		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
1020 		break;
1021 
1022 	case ETHTOOL_ID_INACTIVE:
1023 		/* Restore LED settings */
1024 		ctrl &= ~NIXGE_ID_LED_CTL_EN;
1025 		nixge_ctrl_write_reg(priv, NIXGE_REG_LED_CTL, ctrl);
1026 		break;
1027 	}
1028 
1029 	return 0;
1030 }
1031 
1032 static const struct ethtool_ops nixge_ethtool_ops = {
1033 	.get_drvinfo    = nixge_ethtools_get_drvinfo,
1034 	.get_coalesce   = nixge_ethtools_get_coalesce,
1035 	.set_coalesce   = nixge_ethtools_set_coalesce,
1036 	.set_phys_id    = nixge_ethtools_set_phys_id,
1037 	.get_link_ksettings     = phy_ethtool_get_link_ksettings,
1038 	.set_link_ksettings     = phy_ethtool_set_link_ksettings,
1039 	.get_link		= ethtool_op_get_link,
1040 };
1041 
1042 static int nixge_mdio_read(struct mii_bus *bus, int phy_id, int reg)
1043 {
1044 	struct nixge_priv *priv = bus->priv;
1045 	u32 status, tmp;
1046 	int err;
1047 	u16 device;
1048 
1049 	if (reg & MII_ADDR_C45) {
1050 		device = (reg >> 16) & 0x1f;
1051 
1052 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_ADDR, reg & 0xffff);
1053 
1054 		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_OP_ADDRESS)
1055 			| NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
1056 
1057 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
1058 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
1059 
1060 		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
1061 					      !status, 10, 1000);
1062 		if (err) {
1063 			dev_err(priv->dev, "timeout setting address");
1064 			return err;
1065 		}
1066 
1067 		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_C45_READ) |
1068 			NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
1069 	} else {
1070 		device = reg & 0x1f;
1071 
1072 		tmp = NIXGE_MDIO_CLAUSE22 | NIXGE_MDIO_OP(NIXGE_MDIO_C22_READ) |
1073 			NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
1074 	}
1075 
1076 	nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
1077 	nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
1078 
1079 	err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
1080 				      !status, 10, 1000);
1081 	if (err) {
1082 		dev_err(priv->dev, "timeout setting read command");
1083 		return err;
1084 	}
1085 
1086 	status = nixge_ctrl_read_reg(priv, NIXGE_REG_MDIO_DATA);
1087 
1088 	return status;
1089 }
1090 
1091 static int nixge_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
1092 {
1093 	struct nixge_priv *priv = bus->priv;
1094 	u32 status, tmp;
1095 	u16 device;
1096 	int err;
1097 
1098 	if (reg & MII_ADDR_C45) {
1099 		device = (reg >> 16) & 0x1f;
1100 
1101 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_ADDR, reg & 0xffff);
1102 
1103 		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_OP_ADDRESS)
1104 			| NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
1105 
1106 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
1107 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
1108 
1109 		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
1110 					      !status, 10, 1000);
1111 		if (err) {
1112 			dev_err(priv->dev, "timeout setting address");
1113 			return err;
1114 		}
1115 
1116 		tmp = NIXGE_MDIO_CLAUSE45 | NIXGE_MDIO_OP(NIXGE_MDIO_C45_WRITE)
1117 			| NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
1118 
1119 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_DATA, val);
1120 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
1121 		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
1122 					      !status, 10, 1000);
1123 		if (err)
1124 			dev_err(priv->dev, "timeout setting write command");
1125 	} else {
1126 		device = reg & 0x1f;
1127 
1128 		tmp = NIXGE_MDIO_CLAUSE22 |
1129 			NIXGE_MDIO_OP(NIXGE_MDIO_C22_WRITE) |
1130 			NIXGE_MDIO_ADDR(phy_id) | NIXGE_MDIO_MMD(device);
1131 
1132 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_DATA, val);
1133 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_OP, tmp);
1134 		nixge_ctrl_write_reg(priv, NIXGE_REG_MDIO_CTRL, 1);
1135 
1136 		err = nixge_ctrl_poll_timeout(priv, NIXGE_REG_MDIO_CTRL, status,
1137 					      !status, 10, 1000);
1138 		if (err)
1139 			dev_err(priv->dev, "timeout setting write command");
1140 	}
1141 
1142 	return err;
1143 }
1144 
1145 static int nixge_mdio_setup(struct nixge_priv *priv, struct device_node *np)
1146 {
1147 	struct mii_bus *bus;
1148 
1149 	bus = devm_mdiobus_alloc(priv->dev);
1150 	if (!bus)
1151 		return -ENOMEM;
1152 
1153 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(priv->dev));
1154 	bus->priv = priv;
1155 	bus->name = "nixge_mii_bus";
1156 	bus->read = nixge_mdio_read;
1157 	bus->write = nixge_mdio_write;
1158 	bus->parent = priv->dev;
1159 
1160 	priv->mii_bus = bus;
1161 
1162 	return of_mdiobus_register(bus, np);
1163 }
1164 
1165 static void *nixge_get_nvmem_address(struct device *dev)
1166 {
1167 	struct nvmem_cell *cell;
1168 	size_t cell_size;
1169 	char *mac;
1170 
1171 	cell = nvmem_cell_get(dev, "address");
1172 	if (IS_ERR(cell))
1173 		return cell;
1174 
1175 	mac = nvmem_cell_read(cell, &cell_size);
1176 	nvmem_cell_put(cell);
1177 
1178 	return mac;
1179 }
1180 
1181 static int nixge_probe(struct platform_device *pdev)
1182 {
1183 	struct nixge_priv *priv;
1184 	struct net_device *ndev;
1185 	struct resource *dmares;
1186 	const char *mac_addr;
1187 	int err;
1188 
1189 	ndev = alloc_etherdev(sizeof(*priv));
1190 	if (!ndev)
1191 		return -ENOMEM;
1192 
1193 	platform_set_drvdata(pdev, ndev);
1194 	SET_NETDEV_DEV(ndev, &pdev->dev);
1195 
1196 	ndev->features = NETIF_F_SG;
1197 	ndev->netdev_ops = &nixge_netdev_ops;
1198 	ndev->ethtool_ops = &nixge_ethtool_ops;
1199 
1200 	/* MTU range: 64 - 9000 */
1201 	ndev->min_mtu = 64;
1202 	ndev->max_mtu = NIXGE_JUMBO_MTU;
1203 
1204 	mac_addr = nixge_get_nvmem_address(&pdev->dev);
1205 	if (mac_addr && is_valid_ether_addr(mac_addr))
1206 		ether_addr_copy(ndev->dev_addr, mac_addr);
1207 	else
1208 		eth_hw_addr_random(ndev);
1209 
1210 	priv = netdev_priv(ndev);
1211 	priv->ndev = ndev;
1212 	priv->dev = &pdev->dev;
1213 
1214 	netif_napi_add(ndev, &priv->napi, nixge_poll, NAPI_POLL_WEIGHT);
1215 
1216 	dmares = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1217 	priv->dma_regs = devm_ioremap_resource(&pdev->dev, dmares);
1218 	if (IS_ERR(priv->dma_regs)) {
1219 		netdev_err(ndev, "failed to map dma regs\n");
1220 		return PTR_ERR(priv->dma_regs);
1221 	}
1222 	priv->ctrl_regs = priv->dma_regs + NIXGE_REG_CTRL_OFFSET;
1223 	__nixge_hw_set_mac_address(ndev);
1224 
1225 	priv->tx_irq = platform_get_irq_byname(pdev, "tx");
1226 	if (priv->tx_irq < 0) {
1227 		netdev_err(ndev, "could not find 'tx' irq");
1228 		return priv->tx_irq;
1229 	}
1230 
1231 	priv->rx_irq = platform_get_irq_byname(pdev, "rx");
1232 	if (priv->rx_irq < 0) {
1233 		netdev_err(ndev, "could not find 'rx' irq");
1234 		return priv->rx_irq;
1235 	}
1236 
1237 	priv->coalesce_count_rx = XAXIDMA_DFT_RX_THRESHOLD;
1238 	priv->coalesce_count_tx = XAXIDMA_DFT_TX_THRESHOLD;
1239 
1240 	err = nixge_mdio_setup(priv, pdev->dev.of_node);
1241 	if (err) {
1242 		netdev_err(ndev, "error registering mdio bus");
1243 		goto free_netdev;
1244 	}
1245 
1246 	priv->phy_mode = of_get_phy_mode(pdev->dev.of_node);
1247 	if (priv->phy_mode < 0) {
1248 		netdev_err(ndev, "not find \"phy-mode\" property\n");
1249 		err = -EINVAL;
1250 		goto unregister_mdio;
1251 	}
1252 
1253 	priv->phy_node = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
1254 	if (!priv->phy_node) {
1255 		netdev_err(ndev, "not find \"phy-handle\" property\n");
1256 		err = -EINVAL;
1257 		goto unregister_mdio;
1258 	}
1259 
1260 	err = register_netdev(priv->ndev);
1261 	if (err) {
1262 		netdev_err(ndev, "register_netdev() error (%i)\n", err);
1263 		goto unregister_mdio;
1264 	}
1265 
1266 	return 0;
1267 
1268 unregister_mdio:
1269 	mdiobus_unregister(priv->mii_bus);
1270 
1271 free_netdev:
1272 	free_netdev(ndev);
1273 
1274 	return err;
1275 }
1276 
1277 static int nixge_remove(struct platform_device *pdev)
1278 {
1279 	struct net_device *ndev = platform_get_drvdata(pdev);
1280 	struct nixge_priv *priv = netdev_priv(ndev);
1281 
1282 	unregister_netdev(ndev);
1283 
1284 	mdiobus_unregister(priv->mii_bus);
1285 
1286 	free_netdev(ndev);
1287 
1288 	return 0;
1289 }
1290 
1291 /* Match table for of_platform binding */
1292 static const struct of_device_id nixge_dt_ids[] = {
1293 	{ .compatible = "ni,xge-enet-2.00", },
1294 	{},
1295 };
1296 MODULE_DEVICE_TABLE(of, nixge_dt_ids);
1297 
1298 static struct platform_driver nixge_driver = {
1299 	.probe		= nixge_probe,
1300 	.remove		= nixge_remove,
1301 	.driver		= {
1302 		.name		= "nixge",
1303 		.of_match_table	= of_match_ptr(nixge_dt_ids),
1304 	},
1305 };
1306 module_platform_driver(nixge_driver);
1307 
1308 MODULE_LICENSE("GPL v2");
1309 MODULE_DESCRIPTION("National Instruments XGE Management MAC");
1310 MODULE_AUTHOR("Moritz Fischer <mdf@kernel.org>");
1311