summaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/cadence/at91_ether.c
blob: 3becdb2deb46c8dbfb3faa4e2916e1cdf41bc6d3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
/*
 * Ethernet driver for the Atmel AT91RM9200 (Thunder)
 *
 *  Copyright (C) 2003 SAN People (Pty) Ltd
 *
 * Based on an earlier Atmel EMAC macrocell driver by Atmel and Lineo Inc.
 * Initial version by Rick Bronson 01/11/2003
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/dma-mapping.h>
#include <linux/ethtool.h>
#include <linux/platform_data/macb.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/gfp.h>
#include <linux/phy.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_net.h>
#include <linux/pinctrl/consumer.h>

#include "macb.h"

/* 1518 rounded up */
#define MAX_RBUFF_SZ	0x600
/* max number of receive buffers */
#define MAX_RX_DESCR	9

/* Initialize and start the Receiver and Transmit subsystems */
static int at91ether_start(struct net_device *dev)
{
	struct macb *lp = netdev_priv(dev);
	dma_addr_t addr;
	u32 ctl;
	int i;

	lp->rx_ring = dma_alloc_coherent(&lp->pdev->dev,
					MAX_RX_DESCR * sizeof(struct macb_dma_desc),
					&lp->rx_ring_dma, GFP_KERNEL);
	if (!lp->rx_ring) {
		netdev_err(dev, "unable to alloc rx ring DMA buffer\n");
		return -ENOMEM;
	}

	lp->rx_buffers = dma_alloc_coherent(&lp->pdev->dev,
					MAX_RX_DESCR * MAX_RBUFF_SZ,
					&lp->rx_buffers_dma, GFP_KERNEL);
	if (!lp->rx_buffers) {
		netdev_err(dev, "unable to alloc rx data DMA buffer\n");

		dma_free_coherent(&lp->pdev->dev,
					MAX_RX_DESCR * sizeof(struct macb_dma_desc),
					lp->rx_ring, lp->rx_ring_dma);
		lp->rx_ring = NULL;
		return -ENOMEM;
	}

	addr = lp->rx_buffers_dma;
	for (i = 0; i < MAX_RX_DESCR; i++) {
		lp->rx_ring[i].addr = addr;
		lp->rx_ring[i].ctrl = 0;
		addr += MAX_RBUFF_SZ;
	}

	/* Set the Wrap bit on the last descriptor */
	lp->rx_ring[MAX_RX_DESCR - 1].addr |= MACB_BIT(RX_WRAP);

	/* Reset buffer index */
	lp->rx_tail = 0;

	/* Program address of descriptor list in Rx Buffer Queue register */
	macb_writel(lp, RBQP, lp->rx_ring_dma);

	/* Enable Receive and Transmit */
	ctl = macb_readl(lp, NCR);
	macb_writel(lp, NCR, ctl | MACB_BIT(RE) | MACB_BIT(TE));

	return 0;
}

/* Open the ethernet interface */
static int at91ether_open(struct net_device *dev)
{
	struct macb *lp = netdev_priv(dev);
	u32 ctl;
	int ret;

	/* Clear internal statistics */
	ctl = macb_readl(lp, NCR);
	macb_writel(lp, NCR, ctl | MACB_BIT(CLRSTAT));

	macb_set_hwaddr(lp);

	ret = at91ether_start(dev);
	if (ret)
		return ret;

	/* Enable MAC interrupts */
	macb_writel(lp, IER, MACB_BIT(RCOMP)	|
			     MACB_BIT(RXUBR)	|
			     MACB_BIT(ISR_TUND)	|
			     MACB_BIT(ISR_RLE)	|
			     MACB_BIT(TCOMP)	|
			     MACB_BIT(ISR_ROVR)	|
			     MACB_BIT(HRESP));

	/* schedule a link state check */
	phy_start(lp->phy_dev);

	netif_start_queue(dev);

	return 0;
}

/* Close the interface */
static int at91ether_close(struct net_device *dev)
{
	struct macb *lp = netdev_priv(dev);
	u32 ctl;

	/* Disable Receiver and Transmitter */
	ctl = macb_readl(lp, NCR);
	macb_writel(lp, NCR, ctl & ~(MACB_BIT(TE) | MACB_BIT(RE)));

	/* Disable MAC interrupts */
	macb_writel(lp, IDR, MACB_BIT(RCOMP)	|
			     MACB_BIT(RXUBR)	|
			     MACB_BIT(ISR_TUND)	|
			     MACB_BIT(ISR_RLE)	|
			     MACB_BIT(TCOMP)	|
			     MACB_BIT(ISR_ROVR) |
			     MACB_BIT(HRESP));

	netif_stop_queue(dev);

	dma_free_coherent(&lp->pdev->dev,
				MAX_RX_DESCR * sizeof(struct macb_dma_desc),
				lp->rx_ring, lp->rx_ring_dma);
	lp->rx_ring = NULL;

	dma_free_coherent(&lp->pdev->dev,
				MAX_RX_DESCR * MAX_RBUFF_SZ,
				lp->rx_buffers, lp->rx_buffers_dma);
	lp->rx_buffers = NULL;

	return 0;
}

/* Transmit packet */
static int at91ether_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct macb *lp = netdev_priv(dev);

	if (macb_readl(lp, TSR) & MACB_BIT(RM9200_BNQ)) {
		netif_stop_queue(dev);

		/* Store packet information (to free when Tx completed) */
		lp->skb = skb;
		lp->skb_length = skb->len;
		lp->skb_physaddr = dma_map_single(NULL, skb->data, skb->len,
							DMA_TO_DEVICE);

		/* Set address of the data in the Transmit Address register */
		macb_writel(lp, TAR, lp->skb_physaddr);
		/* Set length of the packet in the Transmit Control register */
		macb_writel(lp, TCR, skb->len);

	} else {
		netdev_err(dev, "%s called, but device is busy!\n", __func__);
		return NETDEV_TX_BUSY;
	}

	return NETDEV_TX_OK;
}

/* Extract received frame from buffer descriptors and sent to upper layers.
 * (Called from interrupt context)
 */
static void at91ether_rx(struct net_device *dev)
{
	struct macb *lp = netdev_priv(dev);
	unsigned char *p_recv;
	struct sk_buff *skb;
	unsigned int pktlen;

	while (lp->rx_ring[lp->rx_tail].addr & MACB_BIT(RX_USED)) {
		p_recv = lp->rx_buffers + lp->rx_tail * MAX_RBUFF_SZ;
		pktlen = MACB_BF(RX_FRMLEN, lp->rx_ring[lp->rx_tail].ctrl);
		skb = netdev_alloc_skb(dev, pktlen + 2);
		if (skb) {
			skb_reserve(skb, 2);
			memcpy(skb_put(skb, pktlen), p_recv, pktlen);

			skb->protocol = eth_type_trans(skb, dev);
			lp->stats.rx_packets++;
			lp->stats.rx_bytes += pktlen;
			netif_rx(skb);
		} else {
			lp->stats.rx_dropped++;
			netdev_notice(dev, "Memory squeeze, dropping packet.\n");
		}

		if (lp->rx_ring[lp->rx_tail].ctrl & MACB_BIT(RX_MHASH_MATCH))
			lp->stats.multicast++;

		/* reset ownership bit */
		lp->rx_ring[lp->rx_tail].addr &= ~MACB_BIT(RX_USED);

		/* wrap after last buffer */
		if (lp->rx_tail == MAX_RX_DESCR - 1)
			lp->rx_tail = 0;
		else
			lp->rx_tail++;
	}
}

/* MAC interrupt handler */
static irqreturn_t at91ether_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct macb *lp = netdev_priv(dev);
	u32 intstatus, ctl;

	/* MAC Interrupt Status register indicates what interrupts are pending.
	 * It is automatically cleared once read.
	 */
	intstatus = macb_readl(lp, ISR);

	/* Receive complete */
	if (intstatus & MACB_BIT(RCOMP))
		at91ether_rx(dev);

	/* Transmit complete */
	if (intstatus & MACB_BIT(TCOMP)) {
		/* The TCOM bit is set even if the transmission failed */
		if (intstatus & (MACB_BIT(ISR_TUND) | MACB_BIT(ISR_RLE)))
			lp->stats.tx_errors++;

		if (lp->skb) {
			dev_kfree_skb_irq(lp->skb);
			lp->skb = NULL;
			dma_unmap_single(NULL, lp->skb_physaddr, lp->skb_length, DMA_TO_DEVICE);
			lp->stats.tx_packets++;
			lp->stats.tx_bytes += lp->skb_length;
		}
		netif_wake_queue(dev);
	}

	/* Work-around for EMAC Errata section 41.3.1 */
	if (intstatus & MACB_BIT(RXUBR)) {
		ctl = macb_readl(lp, NCR);
		macb_writel(lp, NCR, ctl & ~MACB_BIT(RE));
		macb_writel(lp, NCR, ctl | MACB_BIT(RE));
	}

	if (intstatus & MACB_BIT(ISR_ROVR))
		netdev_err(dev, "ROVR error\n");

	return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void at91ether_poll_controller(struct net_device *dev)
{
	unsigned long flags;

	local_irq_save(flags);
	at91ether_interrupt(dev->irq, dev);
	local_irq_restore(flags);
}
#endif

static const struct net_device_ops at91ether_netdev_ops = {
	.ndo_open		= at91ether_open,
	.ndo_stop		= at91ether_close,
	.ndo_start_xmit		= at91ether_start_xmit,
	.ndo_get_stats		= macb_get_stats,
	.ndo_set_rx_mode	= macb_set_rx_mode,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_do_ioctl		= macb_ioctl,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_change_mtu		= eth_change_mtu,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller	= at91ether_poll_controller,
#endif
};

#if defined(CONFIG_OF)
static const struct of_device_id at91ether_dt_ids[] = {
	{ .compatible = "cdns,at91rm9200-emac" },
	{ .compatible = "cdns,emac" },
	{ /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, at91ether_dt_ids);

static int at91ether_get_phy_mode_dt(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;

	if (np)
		return of_get_phy_mode(np);

	return -ENODEV;
}

static int at91ether_get_hwaddr_dt(struct macb *bp)
{
	struct device_node *np = bp->pdev->dev.of_node;

	if (np) {
		const char *mac = of_get_mac_address(np);
		if (mac) {
			memcpy(bp->dev->dev_addr, mac, ETH_ALEN);
			return 0;
		}
	}

	return -ENODEV;
}
#else
static int at91ether_get_phy_mode_dt(struct platform_device *pdev)
{
	return -ENODEV;
}
static int at91ether_get_hwaddr_dt(struct macb *bp)
{
	return -ENODEV;
}
#endif

/* Detect MAC & PHY and perform ethernet interface initialization */
static int __init at91ether_probe(struct platform_device *pdev)
{
	struct macb_platform_data *board_data = pdev->dev.platform_data;
	struct resource *regs;
	struct net_device *dev;
	struct phy_device *phydev;
	struct pinctrl *pinctrl;
	struct macb *lp;
	int res;
	u32 reg;

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!regs)
		return -ENOENT;

	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
	if (IS_ERR(pinctrl)) {
		res = PTR_ERR(pinctrl);
		if (res == -EPROBE_DEFER)
			return res;

		dev_warn(&pdev->dev, "No pinctrl provided\n");
	}

	dev = alloc_etherdev(sizeof(struct macb));
	if (!dev)
		return -ENOMEM;

	lp = netdev_priv(dev);
	lp->pdev = pdev;
	lp->dev = dev;
	spin_lock_init(&lp->lock);

	/* physical base address */
	dev->base_addr = regs->start;
	lp->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
	if (!lp->regs) {
		res = -ENOMEM;
		goto err_free_dev;
	}

	/* Clock */
	lp->pclk = devm_clk_get(&pdev->dev, "ether_clk");
	if (IS_ERR(lp->pclk)) {
		res = PTR_ERR(lp->pclk);
		goto err_free_dev;
	}
	clk_enable(lp->pclk);

	/* Install the interrupt handler */
	dev->irq = platform_get_irq(pdev, 0);
	res = devm_request_irq(&pdev->dev, dev->irq, at91ether_interrupt, 0, dev->name, dev);
	if (res)
		goto err_disable_clock;

	ether_setup(dev);
	dev->netdev_ops = &at91ether_netdev_ops;
	dev->ethtool_ops = &macb_ethtool_ops;
	platform_set_drvdata(pdev, dev);
	SET_NETDEV_DEV(dev, &pdev->dev);

	res = at91ether_get_hwaddr_dt(lp);
	if (res < 0)
		macb_get_hwaddr(lp);

	res = at91ether_get_phy_mode_dt(pdev);
	if (res < 0) {
		if (board_data && board_data->is_rmii)
			lp->phy_interface = PHY_INTERFACE_MODE_RMII;
		else
			lp->phy_interface = PHY_INTERFACE_MODE_MII;
	} else {
		lp->phy_interface = res;
	}

	macb_writel(lp, NCR, 0);

	reg = MACB_BF(CLK, MACB_CLK_DIV32) | MACB_BIT(BIG);
	if (lp->phy_interface == PHY_INTERFACE_MODE_RMII)
		reg |= MACB_BIT(RM9200_RMII);

	macb_writel(lp, NCFGR, reg);

	/* Register the network interface */
	res = register_netdev(dev);
	if (res)
		goto err_disable_clock;

	if (macb_mii_init(lp) != 0)
		goto err_out_unregister_netdev;

	/* will be enabled in open() */
	netif_carrier_off(dev);

	phydev = lp->phy_dev;
	netdev_info(dev, "attached PHY driver [%s] (mii_bus:phy_addr=%s, irq=%d)\n",
				phydev->drv->name, dev_name(&phydev->dev),
				phydev->irq);

	/* Display ethernet banner */
	netdev_info(dev, "AT91 ethernet at 0x%08lx int=%d (%pM)\n",
				dev->base_addr, dev->irq, dev->dev_addr);

	return 0;

err_out_unregister_netdev:
	unregister_netdev(dev);
err_disable_clock:
	clk_disable(lp->pclk);
err_free_dev:
	free_netdev(dev);
	return res;
}

static int at91ether_remove(struct platform_device *pdev)
{
	struct net_device *dev = platform_get_drvdata(pdev);
	struct macb *lp = netdev_priv(dev);

	if (lp->phy_dev)
		phy_disconnect(lp->phy_dev);

	mdiobus_unregister(lp->mii_bus);
	kfree(lp->mii_bus->irq);
	mdiobus_free(lp->mii_bus);
	unregister_netdev(dev);
	clk_disable(lp->pclk);
	free_netdev(dev);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

#ifdef CONFIG_PM
static int at91ether_suspend(struct platform_device *pdev, pm_message_t mesg)
{
	struct net_device *net_dev = platform_get_drvdata(pdev);
	struct macb *lp = netdev_priv(net_dev);

	if (netif_running(net_dev)) {
		netif_stop_queue(net_dev);
		netif_device_detach(net_dev);

		clk_disable(lp->pclk);
	}
	return 0;
}

static int at91ether_resume(struct platform_device *pdev)
{
	struct net_device *net_dev = platform_get_drvdata(pdev);
	struct macb *lp = netdev_priv(net_dev);

	if (netif_running(net_dev)) {
		clk_enable(lp->pclk);

		netif_device_attach(net_dev);
		netif_start_queue(net_dev);
	}
	return 0;
}
#else
#define at91ether_suspend	NULL
#define at91ether_resume	NULL
#endif

static struct platform_driver at91ether_driver = {
	.remove		= at91ether_remove,
	.suspend	= at91ether_suspend,
	.resume		= at91ether_resume,
	.driver		= {
		.name	= "at91_ether",
		.owner	= THIS_MODULE,
		.of_match_table	= of_match_ptr(at91ether_dt_ids),
	},
};

static int __init at91ether_init(void)
{
	return platform_driver_probe(&at91ether_driver, at91ether_probe);
}

static void __exit at91ether_exit(void)
{
	platform_driver_unregister(&at91ether_driver);
}

module_init(at91ether_init)
module_exit(at91ether_exit)

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("AT91RM9200 EMAC Ethernet driver");
MODULE_AUTHOR("Andrew Victor");
MODULE_ALIAS("platform:at91_ether");
OpenPOWER on IntegriCloud