1/*
2 * Ethernet driver for the Atmel AT91RM9200 (Thunder)
3 *
4 *  Copyright (C) 2003 SAN People (Pty) Ltd
5 *
6 * Based on an earlier Atmel EMAC macrocell driver by Atmel and Lineo Inc.
7 * Initial version by Rick Bronson 01/11/2003
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/interrupt.h>
18#include <linux/netdevice.h>
19#include <linux/etherdevice.h>
20#include <linux/skbuff.h>
21#include <linux/dma-mapping.h>
22#include <linux/ethtool.h>
23#include <linux/platform_data/macb.h>
24#include <linux/platform_device.h>
25#include <linux/clk.h>
26#include <linux/gfp.h>
27#include <linux/phy.h>
28#include <linux/io.h>
29#include <linux/of.h>
30#include <linux/of_device.h>
31#include <linux/of_net.h>
32
33#include "macb.h"
34
35/* 1518 rounded up */
36#define MAX_RBUFF_SZ	0x600
37/* max number of receive buffers */
38#define MAX_RX_DESCR	9
39
40/* Initialize and start the Receiver and Transmit subsystems */
41static int at91ether_start(struct net_device *dev)
42{
43	struct macb *lp = netdev_priv(dev);
44	dma_addr_t addr;
45	u32 ctl;
46	int i;
47
48	lp->rx_ring = dma_alloc_coherent(&lp->pdev->dev,
49					 (MAX_RX_DESCR *
50					  sizeof(struct macb_dma_desc)),
51					 &lp->rx_ring_dma, GFP_KERNEL);
52	if (!lp->rx_ring)
53		return -ENOMEM;
54
55	lp->rx_buffers = dma_alloc_coherent(&lp->pdev->dev,
56					    MAX_RX_DESCR * MAX_RBUFF_SZ,
57					    &lp->rx_buffers_dma, GFP_KERNEL);
58	if (!lp->rx_buffers) {
59		dma_free_coherent(&lp->pdev->dev,
60				  MAX_RX_DESCR * sizeof(struct macb_dma_desc),
61				  lp->rx_ring, lp->rx_ring_dma);
62		lp->rx_ring = NULL;
63		return -ENOMEM;
64	}
65
66	addr = lp->rx_buffers_dma;
67	for (i = 0; i < MAX_RX_DESCR; i++) {
68		lp->rx_ring[i].addr = addr;
69		lp->rx_ring[i].ctrl = 0;
70		addr += MAX_RBUFF_SZ;
71	}
72
73	/* Set the Wrap bit on the last descriptor */
74	lp->rx_ring[MAX_RX_DESCR - 1].addr |= MACB_BIT(RX_WRAP);
75
76	/* Reset buffer index */
77	lp->rx_tail = 0;
78
79	/* Program address of descriptor list in Rx Buffer Queue register */
80	macb_writel(lp, RBQP, lp->rx_ring_dma);
81
82	/* Enable Receive and Transmit */
83	ctl = macb_readl(lp, NCR);
84	macb_writel(lp, NCR, ctl | MACB_BIT(RE) | MACB_BIT(TE));
85
86	return 0;
87}
88
89/* Open the ethernet interface */
90static int at91ether_open(struct net_device *dev)
91{
92	struct macb *lp = netdev_priv(dev);
93	u32 ctl;
94	int ret;
95
96	/* Clear internal statistics */
97	ctl = macb_readl(lp, NCR);
98	macb_writel(lp, NCR, ctl | MACB_BIT(CLRSTAT));
99
100	macb_set_hwaddr(lp);
101
102	ret = at91ether_start(dev);
103	if (ret)
104		return ret;
105
106	/* Enable MAC interrupts */
107	macb_writel(lp, IER, MACB_BIT(RCOMP)	|
108			     MACB_BIT(RXUBR)	|
109			     MACB_BIT(ISR_TUND)	|
110			     MACB_BIT(ISR_RLE)	|
111			     MACB_BIT(TCOMP)	|
112			     MACB_BIT(ISR_ROVR)	|
113			     MACB_BIT(HRESP));
114
115	/* schedule a link state check */
116	phy_start(lp->phy_dev);
117
118	netif_start_queue(dev);
119
120	return 0;
121}
122
123/* Close the interface */
124static int at91ether_close(struct net_device *dev)
125{
126	struct macb *lp = netdev_priv(dev);
127	u32 ctl;
128
129	/* Disable Receiver and Transmitter */
130	ctl = macb_readl(lp, NCR);
131	macb_writel(lp, NCR, ctl & ~(MACB_BIT(TE) | MACB_BIT(RE)));
132
133	/* Disable MAC interrupts */
134	macb_writel(lp, IDR, MACB_BIT(RCOMP)	|
135			     MACB_BIT(RXUBR)	|
136			     MACB_BIT(ISR_TUND)	|
137			     MACB_BIT(ISR_RLE)	|
138			     MACB_BIT(TCOMP)	|
139			     MACB_BIT(ISR_ROVR) |
140			     MACB_BIT(HRESP));
141
142	netif_stop_queue(dev);
143
144	dma_free_coherent(&lp->pdev->dev,
145				MAX_RX_DESCR * sizeof(struct macb_dma_desc),
146				lp->rx_ring, lp->rx_ring_dma);
147	lp->rx_ring = NULL;
148
149	dma_free_coherent(&lp->pdev->dev,
150				MAX_RX_DESCR * MAX_RBUFF_SZ,
151				lp->rx_buffers, lp->rx_buffers_dma);
152	lp->rx_buffers = NULL;
153
154	return 0;
155}
156
157/* Transmit packet */
158static int at91ether_start_xmit(struct sk_buff *skb, struct net_device *dev)
159{
160	struct macb *lp = netdev_priv(dev);
161
162	if (macb_readl(lp, TSR) & MACB_BIT(RM9200_BNQ)) {
163		netif_stop_queue(dev);
164
165		/* Store packet information (to free when Tx completed) */
166		lp->skb = skb;
167		lp->skb_length = skb->len;
168		lp->skb_physaddr = dma_map_single(NULL, skb->data, skb->len,
169							DMA_TO_DEVICE);
170
171		/* Set address of the data in the Transmit Address register */
172		macb_writel(lp, TAR, lp->skb_physaddr);
173		/* Set length of the packet in the Transmit Control register */
174		macb_writel(lp, TCR, skb->len);
175
176	} else {
177		netdev_err(dev, "%s called, but device is busy!\n", __func__);
178		return NETDEV_TX_BUSY;
179	}
180
181	return NETDEV_TX_OK;
182}
183
184/* Extract received frame from buffer descriptors and sent to upper layers.
185 * (Called from interrupt context)
186 */
187static void at91ether_rx(struct net_device *dev)
188{
189	struct macb *lp = netdev_priv(dev);
190	unsigned char *p_recv;
191	struct sk_buff *skb;
192	unsigned int pktlen;
193
194	while (lp->rx_ring[lp->rx_tail].addr & MACB_BIT(RX_USED)) {
195		p_recv = lp->rx_buffers + lp->rx_tail * MAX_RBUFF_SZ;
196		pktlen = MACB_BF(RX_FRMLEN, lp->rx_ring[lp->rx_tail].ctrl);
197		skb = netdev_alloc_skb(dev, pktlen + 2);
198		if (skb) {
199			skb_reserve(skb, 2);
200			memcpy(skb_put(skb, pktlen), p_recv, pktlen);
201
202			skb->protocol = eth_type_trans(skb, dev);
203			lp->stats.rx_packets++;
204			lp->stats.rx_bytes += pktlen;
205			netif_rx(skb);
206		} else {
207			lp->stats.rx_dropped++;
208		}
209
210		if (lp->rx_ring[lp->rx_tail].ctrl & MACB_BIT(RX_MHASH_MATCH))
211			lp->stats.multicast++;
212
213		/* reset ownership bit */
214		lp->rx_ring[lp->rx_tail].addr &= ~MACB_BIT(RX_USED);
215
216		/* wrap after last buffer */
217		if (lp->rx_tail == MAX_RX_DESCR - 1)
218			lp->rx_tail = 0;
219		else
220			lp->rx_tail++;
221	}
222}
223
224/* MAC interrupt handler */
225static irqreturn_t at91ether_interrupt(int irq, void *dev_id)
226{
227	struct net_device *dev = dev_id;
228	struct macb *lp = netdev_priv(dev);
229	u32 intstatus, ctl;
230
231	/* MAC Interrupt Status register indicates what interrupts are pending.
232	 * It is automatically cleared once read.
233	 */
234	intstatus = macb_readl(lp, ISR);
235
236	/* Receive complete */
237	if (intstatus & MACB_BIT(RCOMP))
238		at91ether_rx(dev);
239
240	/* Transmit complete */
241	if (intstatus & MACB_BIT(TCOMP)) {
242		/* The TCOM bit is set even if the transmission failed */
243		if (intstatus & (MACB_BIT(ISR_TUND) | MACB_BIT(ISR_RLE)))
244			lp->stats.tx_errors++;
245
246		if (lp->skb) {
247			dev_kfree_skb_irq(lp->skb);
248			lp->skb = NULL;
249			dma_unmap_single(NULL, lp->skb_physaddr, lp->skb_length, DMA_TO_DEVICE);
250			lp->stats.tx_packets++;
251			lp->stats.tx_bytes += lp->skb_length;
252		}
253		netif_wake_queue(dev);
254	}
255
256	/* Work-around for EMAC Errata section 41.3.1 */
257	if (intstatus & MACB_BIT(RXUBR)) {
258		ctl = macb_readl(lp, NCR);
259		macb_writel(lp, NCR, ctl & ~MACB_BIT(RE));
260		macb_writel(lp, NCR, ctl | MACB_BIT(RE));
261	}
262
263	if (intstatus & MACB_BIT(ISR_ROVR))
264		netdev_err(dev, "ROVR error\n");
265
266	return IRQ_HANDLED;
267}
268
269#ifdef CONFIG_NET_POLL_CONTROLLER
270static void at91ether_poll_controller(struct net_device *dev)
271{
272	unsigned long flags;
273
274	local_irq_save(flags);
275	at91ether_interrupt(dev->irq, dev);
276	local_irq_restore(flags);
277}
278#endif
279
280static const struct net_device_ops at91ether_netdev_ops = {
281	.ndo_open		= at91ether_open,
282	.ndo_stop		= at91ether_close,
283	.ndo_start_xmit		= at91ether_start_xmit,
284	.ndo_get_stats		= macb_get_stats,
285	.ndo_set_rx_mode	= macb_set_rx_mode,
286	.ndo_set_mac_address	= eth_mac_addr,
287	.ndo_do_ioctl		= macb_ioctl,
288	.ndo_validate_addr	= eth_validate_addr,
289	.ndo_change_mtu		= eth_change_mtu,
290#ifdef CONFIG_NET_POLL_CONTROLLER
291	.ndo_poll_controller	= at91ether_poll_controller,
292#endif
293};
294
295#if defined(CONFIG_OF)
296static const struct of_device_id at91ether_dt_ids[] = {
297	{ .compatible = "cdns,at91rm9200-emac" },
298	{ .compatible = "cdns,emac" },
299	{ /* sentinel */ }
300};
301MODULE_DEVICE_TABLE(of, at91ether_dt_ids);
302#endif
303
304/* Detect MAC & PHY and perform ethernet interface initialization */
305static int __init at91ether_probe(struct platform_device *pdev)
306{
307	struct macb_platform_data *board_data = dev_get_platdata(&pdev->dev);
308	struct resource *regs;
309	struct net_device *dev;
310	struct phy_device *phydev;
311	struct macb *lp;
312	int res;
313	u32 reg;
314	const char *mac;
315
316	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
317	if (!regs)
318		return -ENOENT;
319
320	dev = alloc_etherdev(sizeof(struct macb));
321	if (!dev)
322		return -ENOMEM;
323
324	lp = netdev_priv(dev);
325	lp->pdev = pdev;
326	lp->dev = dev;
327	spin_lock_init(&lp->lock);
328
329	/* physical base address */
330	dev->base_addr = regs->start;
331	lp->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
332	if (!lp->regs) {
333		res = -ENOMEM;
334		goto err_free_dev;
335	}
336
337	/* Clock */
338	lp->pclk = devm_clk_get(&pdev->dev, "ether_clk");
339	if (IS_ERR(lp->pclk)) {
340		res = PTR_ERR(lp->pclk);
341		goto err_free_dev;
342	}
343	clk_enable(lp->pclk);
344
345	lp->hclk = ERR_PTR(-ENOENT);
346	lp->tx_clk = ERR_PTR(-ENOENT);
347
348	/* Install the interrupt handler */
349	dev->irq = platform_get_irq(pdev, 0);
350	res = devm_request_irq(&pdev->dev, dev->irq, at91ether_interrupt, 0, dev->name, dev);
351	if (res)
352		goto err_disable_clock;
353
354	dev->netdev_ops = &at91ether_netdev_ops;
355	dev->ethtool_ops = &macb_ethtool_ops;
356	platform_set_drvdata(pdev, dev);
357	SET_NETDEV_DEV(dev, &pdev->dev);
358
359	mac = of_get_mac_address(pdev->dev.of_node);
360	if (mac)
361		memcpy(lp->dev->dev_addr, mac, ETH_ALEN);
362	else
363		macb_get_hwaddr(lp);
364
365	res = of_get_phy_mode(pdev->dev.of_node);
366	if (res < 0) {
367		if (board_data && board_data->is_rmii)
368			lp->phy_interface = PHY_INTERFACE_MODE_RMII;
369		else
370			lp->phy_interface = PHY_INTERFACE_MODE_MII;
371	} else {
372		lp->phy_interface = res;
373	}
374
375	macb_writel(lp, NCR, 0);
376
377	reg = MACB_BF(CLK, MACB_CLK_DIV32) | MACB_BIT(BIG);
378	if (lp->phy_interface == PHY_INTERFACE_MODE_RMII)
379		reg |= MACB_BIT(RM9200_RMII);
380
381	macb_writel(lp, NCFGR, reg);
382
383	/* Register the network interface */
384	res = register_netdev(dev);
385	if (res)
386		goto err_disable_clock;
387
388	res = macb_mii_init(lp);
389	if (res)
390		goto err_out_unregister_netdev;
391
392	/* will be enabled in open() */
393	netif_carrier_off(dev);
394
395	phydev = lp->phy_dev;
396	netdev_info(dev, "attached PHY driver [%s] (mii_bus:phy_addr=%s, irq=%d)\n",
397				phydev->drv->name, dev_name(&phydev->dev),
398				phydev->irq);
399
400	/* Display ethernet banner */
401	netdev_info(dev, "AT91 ethernet at 0x%08lx int=%d (%pM)\n",
402				dev->base_addr, dev->irq, dev->dev_addr);
403
404	return 0;
405
406err_out_unregister_netdev:
407	unregister_netdev(dev);
408err_disable_clock:
409	clk_disable(lp->pclk);
410err_free_dev:
411	free_netdev(dev);
412	return res;
413}
414
415static int at91ether_remove(struct platform_device *pdev)
416{
417	struct net_device *dev = platform_get_drvdata(pdev);
418	struct macb *lp = netdev_priv(dev);
419
420	if (lp->phy_dev)
421		phy_disconnect(lp->phy_dev);
422
423	mdiobus_unregister(lp->mii_bus);
424	kfree(lp->mii_bus->irq);
425	mdiobus_free(lp->mii_bus);
426	unregister_netdev(dev);
427	clk_disable(lp->pclk);
428	free_netdev(dev);
429
430	return 0;
431}
432
433#ifdef CONFIG_PM
434static int at91ether_suspend(struct platform_device *pdev, pm_message_t mesg)
435{
436	struct net_device *net_dev = platform_get_drvdata(pdev);
437	struct macb *lp = netdev_priv(net_dev);
438
439	if (netif_running(net_dev)) {
440		netif_stop_queue(net_dev);
441		netif_device_detach(net_dev);
442
443		clk_disable(lp->pclk);
444	}
445	return 0;
446}
447
448static int at91ether_resume(struct platform_device *pdev)
449{
450	struct net_device *net_dev = platform_get_drvdata(pdev);
451	struct macb *lp = netdev_priv(net_dev);
452
453	if (netif_running(net_dev)) {
454		clk_enable(lp->pclk);
455
456		netif_device_attach(net_dev);
457		netif_start_queue(net_dev);
458	}
459	return 0;
460}
461#else
462#define at91ether_suspend	NULL
463#define at91ether_resume	NULL
464#endif
465
466static struct platform_driver at91ether_driver = {
467	.remove		= at91ether_remove,
468	.suspend	= at91ether_suspend,
469	.resume		= at91ether_resume,
470	.driver		= {
471		.name	= "at91_ether",
472		.owner	= THIS_MODULE,
473		.of_match_table	= of_match_ptr(at91ether_dt_ids),
474	},
475};
476
477module_platform_driver_probe(at91ether_driver, at91ether_probe);
478
479MODULE_LICENSE("GPL");
480MODULE_DESCRIPTION("AT91RM9200 EMAC Ethernet driver");
481MODULE_AUTHOR("Andrew Victor");
482MODULE_ALIAS("platform:at91_ether");
483