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1// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause2/*3 *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.4 *   Copyright (c) 2014, I2SE GmbH5 */6 7/*   This module implements the Qualcomm Atheros SPI protocol for8 *   kernel-based SPI device; it is essentially an Ethernet-to-SPI9 *   serial converter;10 */11 12#include <linux/errno.h>13#include <linux/etherdevice.h>14#include <linux/if_arp.h>15#include <linux/if_ether.h>16#include <linux/init.h>17#include <linux/interrupt.h>18#include <linux/jiffies.h>19#include <linux/kernel.h>20#include <linux/kthread.h>21#include <linux/module.h>22#include <linux/moduleparam.h>23#include <linux/netdevice.h>24#include <linux/of.h>25#include <linux/of_net.h>26#include <linux/sched.h>27#include <linux/skbuff.h>28#include <linux/spi/spi.h>29#include <linux/types.h>30 31#include "qca_7k.h"32#include "qca_7k_common.h"33#include "qca_debug.h"34#include "qca_spi.h"35 36#define MAX_DMA_BURST_LEN 500037 38#define SPI_INTR 039 40/*   Modules parameters     */41#define QCASPI_CLK_SPEED_MIN 100000042#define QCASPI_CLK_SPEED_MAX 1600000043#define QCASPI_CLK_SPEED     800000044static int qcaspi_clkspeed;45module_param(qcaspi_clkspeed, int, 0);46MODULE_PARM_DESC(qcaspi_clkspeed, "SPI bus clock speed (Hz). Use 1000000-16000000.");47 48#define QCASPI_BURST_LEN_MIN 149#define QCASPI_BURST_LEN_MAX MAX_DMA_BURST_LEN50static int qcaspi_burst_len = MAX_DMA_BURST_LEN;51module_param(qcaspi_burst_len, int, 0);52MODULE_PARM_DESC(qcaspi_burst_len, "Number of data bytes per burst. Use 1-5000.");53 54#define QCASPI_PLUGGABLE_MIN 055#define QCASPI_PLUGGABLE_MAX 156static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;57module_param(qcaspi_pluggable, int, 0);58MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");59 60#define QCASPI_WRITE_VERIFY_MIN 061#define QCASPI_WRITE_VERIFY_MAX 362static int wr_verify = QCASPI_WRITE_VERIFY_MIN;63module_param(wr_verify, int, 0);64MODULE_PARM_DESC(wr_verify, "SPI register write verify trails. Use 0-3.");65 66#define QCASPI_TX_TIMEOUT (1 * HZ)67#define QCASPI_QCA7K_REBOOT_TIME_MS 100068 69static void70start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)71{72	*intr_cause = 0;73 74	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);75	qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);76	netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);77}78 79static void80end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)81{82	u16 intr_enable = (SPI_INT_CPU_ON |83			   SPI_INT_PKT_AVLBL |84			   SPI_INT_RDBUF_ERR |85			   SPI_INT_WRBUF_ERR);86 87	qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause, 0);88	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable, wr_verify);89	netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);90}91 92static u3293qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)94{95	__be16 cmd;96	struct spi_message msg;97	struct spi_transfer transfer[2];98	int ret;99 100	memset(&transfer, 0, sizeof(transfer));101	spi_message_init(&msg);102 103	cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);104	transfer[0].tx_buf = &cmd;105	transfer[0].len = QCASPI_CMD_LEN;106	transfer[1].tx_buf = src;107	transfer[1].len = len;108 109	spi_message_add_tail(&transfer[0], &msg);110	spi_message_add_tail(&transfer[1], &msg);111	ret = spi_sync(qca->spi_dev, &msg);112 113	if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {114		qcaspi_spi_error(qca);115		return 0;116	}117 118	return len;119}120 121static u32122qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)123{124	struct spi_message msg;125	struct spi_transfer transfer;126	int ret;127 128	memset(&transfer, 0, sizeof(transfer));129	spi_message_init(&msg);130 131	transfer.tx_buf = src;132	transfer.len = len;133 134	spi_message_add_tail(&transfer, &msg);135	ret = spi_sync(qca->spi_dev, &msg);136 137	if (ret || (msg.actual_length != len)) {138		qcaspi_spi_error(qca);139		return 0;140	}141 142	return len;143}144 145static u32146qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)147{148	struct spi_message msg;149	__be16 cmd;150	struct spi_transfer transfer[2];151	int ret;152 153	memset(&transfer, 0, sizeof(transfer));154	spi_message_init(&msg);155 156	cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);157	transfer[0].tx_buf = &cmd;158	transfer[0].len = QCASPI_CMD_LEN;159	transfer[1].rx_buf = dst;160	transfer[1].len = len;161 162	spi_message_add_tail(&transfer[0], &msg);163	spi_message_add_tail(&transfer[1], &msg);164	ret = spi_sync(qca->spi_dev, &msg);165 166	if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {167		qcaspi_spi_error(qca);168		return 0;169	}170 171	return len;172}173 174static u32175qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)176{177	struct spi_message msg;178	struct spi_transfer transfer;179	int ret;180 181	memset(&transfer, 0, sizeof(transfer));182	spi_message_init(&msg);183 184	transfer.rx_buf = dst;185	transfer.len = len;186 187	spi_message_add_tail(&transfer, &msg);188	ret = spi_sync(qca->spi_dev, &msg);189 190	if (ret || (msg.actual_length != len)) {191		qcaspi_spi_error(qca);192		return 0;193	}194 195	return len;196}197 198static int199qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)200{201	__be16 tx_data;202	struct spi_message msg;203	struct spi_transfer transfer;204	int ret;205 206	memset(&transfer, 0, sizeof(transfer));207 208	spi_message_init(&msg);209 210	tx_data = cpu_to_be16(cmd);211	transfer.len = sizeof(cmd);212	transfer.tx_buf = &tx_data;213	spi_message_add_tail(&transfer, &msg);214 215	ret = spi_sync(qca->spi_dev, &msg);216 217	if (!ret)218		ret = msg.status;219 220	if (ret)221		qcaspi_spi_error(qca);222 223	return ret;224}225 226static int227qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)228{229	u32 count;230	u32 written;231	u32 offset;232	u32 len;233 234	len = skb->len;235 236	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len, wr_verify);237	if (qca->legacy_mode)238		qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);239 240	offset = 0;241	while (len) {242		count = len;243		if (count > qca->burst_len)244			count = qca->burst_len;245 246		if (qca->legacy_mode) {247			written = qcaspi_write_legacy(qca,248						      skb->data + offset,249						      count);250		} else {251			written = qcaspi_write_burst(qca,252						     skb->data + offset,253						     count);254		}255 256		if (written != count)257			return -1;258 259		offset += count;260		len -= count;261	}262 263	return 0;264}265 266static int267qcaspi_transmit(struct qcaspi *qca)268{269	struct net_device_stats *n_stats = &qca->net_dev->stats;270	u16 available = 0;271	u32 pkt_len;272	u16 new_head;273	u16 packets = 0;274 275	if (qca->txr.skb[qca->txr.head] == NULL)276		return 0;277 278	qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);279 280	if (available > QCASPI_HW_BUF_LEN) {281		/* This could only happen by interferences on the SPI line.282		 * So retry later ...283		 */284		qca->stats.buf_avail_err++;285		return -1;286	}287 288	while (qca->txr.skb[qca->txr.head]) {289		pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;290 291		if (available < pkt_len) {292			if (packets == 0)293				qca->stats.write_buf_miss++;294			break;295		}296 297		if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {298			qca->stats.write_err++;299			return -1;300		}301 302		packets++;303		n_stats->tx_packets++;304		n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;305		available -= pkt_len;306 307		/* remove the skb from the queue */308		/* XXX After inconsistent lock states netif_tx_lock()309		 * has been replaced by netif_tx_lock_bh() and so on.310		 */311		netif_tx_lock_bh(qca->net_dev);312		dev_kfree_skb(qca->txr.skb[qca->txr.head]);313		qca->txr.skb[qca->txr.head] = NULL;314		qca->txr.size -= pkt_len;315		new_head = qca->txr.head + 1;316		if (new_head >= qca->txr.count)317			new_head = 0;318		qca->txr.head = new_head;319		if (netif_queue_stopped(qca->net_dev))320			netif_wake_queue(qca->net_dev);321		netif_tx_unlock_bh(qca->net_dev);322	}323 324	return 0;325}326 327static int328qcaspi_receive(struct qcaspi *qca)329{330	struct net_device *net_dev = qca->net_dev;331	struct net_device_stats *n_stats = &net_dev->stats;332	u16 available = 0;333	u32 bytes_read;334	u8 *cp;335 336	/* Allocate rx SKB if we don't have one available. */337	if (!qca->rx_skb) {338		qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,339							net_dev->mtu +340							VLAN_ETH_HLEN);341		if (!qca->rx_skb) {342			netdev_dbg(net_dev, "out of RX resources\n");343			qca->stats.out_of_mem++;344			return -1;345		}346	}347 348	/* Read the packet size. */349	qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);350 351	netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %04x\n",352		   available);353 354	if (available > QCASPI_HW_BUF_LEN + QCASPI_HW_PKT_LEN) {355		/* This could only happen by interferences on the SPI line.356		 * So retry later ...357		 */358		qca->stats.buf_avail_err++;359		return -1;360	} else if (available == 0) {361		netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");362		return -1;363	}364 365	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available, wr_verify);366 367	if (qca->legacy_mode)368		qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);369 370	while (available) {371		u32 count = available;372 373		if (count > qca->burst_len)374			count = qca->burst_len;375 376		if (qca->legacy_mode) {377			bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,378							count);379		} else {380			bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,381						       count);382		}383 384		netdev_dbg(net_dev, "available: %d, byte read: %d\n",385			   available, bytes_read);386 387		if (bytes_read) {388			available -= bytes_read;389		} else {390			qca->stats.read_err++;391			return -1;392		}393 394		cp = qca->rx_buffer;395 396		while ((bytes_read--) && (qca->rx_skb)) {397			s32 retcode;398 399			retcode = qcafrm_fsm_decode(&qca->frm_handle,400						    qca->rx_skb->data,401						    skb_tailroom(qca->rx_skb),402						    *cp);403			cp++;404			switch (retcode) {405			case QCAFRM_GATHER:406			case QCAFRM_NOHEAD:407				break;408			case QCAFRM_NOTAIL:409				netdev_dbg(net_dev, "no RX tail\n");410				n_stats->rx_errors++;411				n_stats->rx_dropped++;412				break;413			case QCAFRM_INVLEN:414				netdev_dbg(net_dev, "invalid RX length\n");415				n_stats->rx_errors++;416				n_stats->rx_dropped++;417				break;418			default:419				qca->rx_skb->dev = qca->net_dev;420				n_stats->rx_packets++;421				n_stats->rx_bytes += retcode;422				skb_put(qca->rx_skb, retcode);423				qca->rx_skb->protocol = eth_type_trans(424					qca->rx_skb, qca->rx_skb->dev);425				skb_checksum_none_assert(qca->rx_skb);426				netif_rx(qca->rx_skb);427				qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,428					net_dev->mtu + VLAN_ETH_HLEN);429				if (!qca->rx_skb) {430					netdev_dbg(net_dev, "out of RX resources\n");431					n_stats->rx_errors++;432					qca->stats.out_of_mem++;433					break;434				}435			}436		}437	}438 439	return 0;440}441 442/*   Check that tx ring stores only so much bytes443 *   that fit into the internal QCA buffer.444 */445 446static int447qcaspi_tx_ring_has_space(struct tx_ring *txr)448{449	if (txr->skb[txr->tail])450		return 0;451 452	return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;453}454 455/*   Flush the tx ring. This function is only safe to456 *   call from the qcaspi_spi_thread.457 */458 459static void460qcaspi_flush_tx_ring(struct qcaspi *qca)461{462	int i;463 464	/* XXX After inconsistent lock states netif_tx_lock()465	 * has been replaced by netif_tx_lock_bh() and so on.466	 */467	netif_tx_lock_bh(qca->net_dev);468	for (i = 0; i < QCASPI_TX_RING_MAX_LEN; i++) {469		if (qca->txr.skb[i]) {470			dev_kfree_skb(qca->txr.skb[i]);471			qca->txr.skb[i] = NULL;472			qca->net_dev->stats.tx_dropped++;473		}474	}475	qca->txr.tail = 0;476	qca->txr.head = 0;477	qca->txr.size = 0;478	netif_tx_unlock_bh(qca->net_dev);479}480 481static void482qcaspi_qca7k_sync(struct qcaspi *qca, int event)483{484	u16 signature = 0;485	u16 spi_config;486	u16 wrbuf_space = 0;487 488	if (event == QCASPI_EVENT_CPUON) {489		/* Read signature twice, if not valid490		 * go back to unknown state.491		 */492		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);493		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);494		if (signature != QCASPI_GOOD_SIGNATURE) {495			if (qca->sync == QCASPI_SYNC_READY)496				qca->stats.bad_signature++;497 498			qca->sync = QCASPI_SYNC_UNKNOWN;499			netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");500			return;501		} else {502			/* ensure that the WRBUF is empty */503			qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,504					     &wrbuf_space);505			if (wrbuf_space != QCASPI_HW_BUF_LEN) {506				netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");507				qca->sync = QCASPI_SYNC_UNKNOWN;508			} else {509				netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");510				qca->sync = QCASPI_SYNC_READY;511				return;512			}513		}514	}515 516	switch (qca->sync) {517	case QCASPI_SYNC_READY:518		/* Check signature twice, if not valid go to unknown state. */519		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);520		if (signature != QCASPI_GOOD_SIGNATURE)521			qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);522 523		if (signature != QCASPI_GOOD_SIGNATURE) {524			qca->sync = QCASPI_SYNC_UNKNOWN;525			qca->stats.bad_signature++;526			netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");527			/* don't reset right away */528			return;529		}530		break;531	case QCASPI_SYNC_UNKNOWN:532		/* Read signature, if not valid stay in unknown state */533		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);534		if (signature != QCASPI_GOOD_SIGNATURE) {535			netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");536			return;537		}538 539		/* TODO: use GPIO to reset QCA7000 in legacy mode*/540		netdev_dbg(qca->net_dev, "sync: resetting device.\n");541		qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);542		spi_config |= QCASPI_SLAVE_RESET_BIT;543		qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config, 0);544 545		qca->sync = QCASPI_SYNC_RESET;546		qca->stats.trig_reset++;547		qca->reset_count = 0;548		break;549	case QCASPI_SYNC_RESET:550		qca->reset_count++;551		netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",552			   qca->reset_count);553		if (qca->reset_count >= QCASPI_RESET_TIMEOUT) {554			/* reset did not seem to take place, try again */555			qca->sync = QCASPI_SYNC_UNKNOWN;556			qca->stats.reset_timeout++;557			netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");558		}559		break;560	}561}562 563static int564qcaspi_spi_thread(void *data)565{566	struct qcaspi *qca = data;567	u16 intr_cause = 0;568 569	netdev_info(qca->net_dev, "SPI thread created\n");570	while (!kthread_should_stop()) {571		set_current_state(TASK_INTERRUPTIBLE);572		if (kthread_should_park()) {573			netif_tx_disable(qca->net_dev);574			netif_carrier_off(qca->net_dev);575			qcaspi_flush_tx_ring(qca);576			kthread_parkme();577			if (qca->sync == QCASPI_SYNC_READY) {578				netif_carrier_on(qca->net_dev);579				netif_wake_queue(qca->net_dev);580			}581			continue;582		}583 584		if (!test_bit(SPI_INTR, &qca->intr) &&585		    !qca->txr.skb[qca->txr.head])586			schedule();587 588		set_current_state(TASK_RUNNING);589 590		netdev_dbg(qca->net_dev, "have work to do. int: %lu, tx_skb: %p\n",591			   qca->intr,592			   qca->txr.skb[qca->txr.head]);593 594		qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);595 596		if (qca->sync != QCASPI_SYNC_READY) {597			netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",598				   (unsigned int)qca->sync);599			netif_stop_queue(qca->net_dev);600			netif_carrier_off(qca->net_dev);601			qcaspi_flush_tx_ring(qca);602			msleep(QCASPI_QCA7K_REBOOT_TIME_MS);603		}604 605		if (test_and_clear_bit(SPI_INTR, &qca->intr)) {606			start_spi_intr_handling(qca, &intr_cause);607 608			if (intr_cause & SPI_INT_CPU_ON) {609				qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);610 611				/* Frame decoding in progress */612				if (qca->frm_handle.state != qca->frm_handle.init)613					qca->net_dev->stats.rx_dropped++;614 615				qcafrm_fsm_init_spi(&qca->frm_handle);616				qca->stats.device_reset++;617 618				/* not synced. */619				if (qca->sync != QCASPI_SYNC_READY)620					continue;621 622				netif_wake_queue(qca->net_dev);623				netif_carrier_on(qca->net_dev);624			}625 626			if (intr_cause & SPI_INT_RDBUF_ERR) {627				/* restart sync */628				netdev_dbg(qca->net_dev, "===> rdbuf error!\n");629				qca->stats.read_buf_err++;630				qca->sync = QCASPI_SYNC_UNKNOWN;631				continue;632			}633 634			if (intr_cause & SPI_INT_WRBUF_ERR) {635				/* restart sync */636				netdev_dbg(qca->net_dev, "===> wrbuf error!\n");637				qca->stats.write_buf_err++;638				qca->sync = QCASPI_SYNC_UNKNOWN;639				continue;640			}641 642			/* can only handle other interrupts643			 * if sync has occurred644			 */645			if (qca->sync == QCASPI_SYNC_READY) {646				if (intr_cause & SPI_INT_PKT_AVLBL)647					qcaspi_receive(qca);648			}649 650			end_spi_intr_handling(qca, intr_cause);651		}652 653		if (qca->sync == QCASPI_SYNC_READY)654			qcaspi_transmit(qca);655	}656	set_current_state(TASK_RUNNING);657	netdev_info(qca->net_dev, "SPI thread exit\n");658 659	return 0;660}661 662static irqreturn_t663qcaspi_intr_handler(int irq, void *data)664{665	struct qcaspi *qca = data;666 667	set_bit(SPI_INTR, &qca->intr);668	if (qca->spi_thread)669		wake_up_process(qca->spi_thread);670 671	return IRQ_HANDLED;672}673 674static int675qcaspi_netdev_open(struct net_device *dev)676{677	struct qcaspi *qca = netdev_priv(dev);678	struct task_struct *thread;679 680	if (!qca)681		return -EINVAL;682 683	set_bit(SPI_INTR, &qca->intr);684	qca->sync = QCASPI_SYNC_UNKNOWN;685	qcafrm_fsm_init_spi(&qca->frm_handle);686 687	thread = kthread_run((void *)qcaspi_spi_thread,688			     qca, "%s", dev->name);689 690	if (IS_ERR(thread)) {691		netdev_err(dev, "%s: unable to start kernel thread.\n",692			   QCASPI_DRV_NAME);693		return PTR_ERR(thread);694	}695 696	qca->spi_thread = thread;697 698	enable_irq(qca->spi_dev->irq);699 700	/* SPI thread takes care of TX queue */701 702	return 0;703}704 705static int706qcaspi_netdev_close(struct net_device *dev)707{708	struct qcaspi *qca = netdev_priv(dev);709 710	netif_stop_queue(dev);711 712	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);713	disable_irq(qca->spi_dev->irq);714 715	if (qca->spi_thread) {716		kthread_stop(qca->spi_thread);717		qca->spi_thread = NULL;718	}719	qcaspi_flush_tx_ring(qca);720 721	return 0;722}723 724static netdev_tx_t725qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)726{727	u32 frame_len;728	u8 *ptmp;729	struct qcaspi *qca = netdev_priv(dev);730	u16 new_tail;731	struct sk_buff *tskb;732	u8 pad_len = 0;733 734	if (skb->len < QCAFRM_MIN_LEN)735		pad_len = QCAFRM_MIN_LEN - skb->len;736 737	if (qca->txr.skb[qca->txr.tail]) {738		netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");739		netif_stop_queue(qca->net_dev);740		qca->stats.ring_full++;741		return NETDEV_TX_BUSY;742	}743 744	if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||745	    (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {746		tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,747				       QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);748		if (!tskb) {749			qca->stats.out_of_mem++;750			return NETDEV_TX_BUSY;751		}752		dev_kfree_skb(skb);753		skb = tskb;754	}755 756	frame_len = skb->len + pad_len;757 758	ptmp = skb_push(skb, QCAFRM_HEADER_LEN);759	qcafrm_create_header(ptmp, frame_len);760 761	if (pad_len) {762		ptmp = skb_put_zero(skb, pad_len);763	}764 765	ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);766	qcafrm_create_footer(ptmp);767 768	netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",769		   skb->len);770 771	qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;772 773	new_tail = qca->txr.tail + 1;774	if (new_tail >= qca->txr.count)775		new_tail = 0;776 777	qca->txr.skb[qca->txr.tail] = skb;778	qca->txr.tail = new_tail;779 780	if (!qcaspi_tx_ring_has_space(&qca->txr)) {781		netif_stop_queue(qca->net_dev);782		qca->stats.ring_full++;783	}784 785	netif_trans_update(dev);786 787	if (qca->spi_thread)788		wake_up_process(qca->spi_thread);789 790	return NETDEV_TX_OK;791}792 793static void794qcaspi_netdev_tx_timeout(struct net_device *dev, unsigned int txqueue)795{796	struct qcaspi *qca = netdev_priv(dev);797 798	netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",799		    jiffies, jiffies - dev_trans_start(dev));800	qca->net_dev->stats.tx_errors++;801	/* Trigger tx queue flush and QCA7000 reset */802	qca->sync = QCASPI_SYNC_UNKNOWN;803 804	if (qca->spi_thread)805		wake_up_process(qca->spi_thread);806}807 808static int809qcaspi_netdev_init(struct net_device *dev)810{811	struct qcaspi *qca = netdev_priv(dev);812 813	dev->mtu = QCAFRM_MAX_MTU;814	dev->type = ARPHRD_ETHER;815	qca->clkspeed = qcaspi_clkspeed;816	qca->burst_len = qcaspi_burst_len;817	qca->spi_thread = NULL;818	qca->buffer_size = (QCAFRM_MAX_MTU + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +819		QCAFRM_FOOTER_LEN + QCASPI_HW_PKT_LEN) * QCASPI_RX_MAX_FRAMES;820 821	memset(&qca->stats, 0, sizeof(struct qcaspi_stats));822 823	qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);824	if (!qca->rx_buffer)825		return -ENOBUFS;826 827	qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +828						VLAN_ETH_HLEN);829	if (!qca->rx_skb) {830		kfree(qca->rx_buffer);831		netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");832		return -ENOBUFS;833	}834 835	return 0;836}837 838static void839qcaspi_netdev_uninit(struct net_device *dev)840{841	struct qcaspi *qca = netdev_priv(dev);842 843	kfree(qca->rx_buffer);844	qca->buffer_size = 0;845	dev_kfree_skb(qca->rx_skb);846}847 848static const struct net_device_ops qcaspi_netdev_ops = {849	.ndo_init = qcaspi_netdev_init,850	.ndo_uninit = qcaspi_netdev_uninit,851	.ndo_open = qcaspi_netdev_open,852	.ndo_stop = qcaspi_netdev_close,853	.ndo_start_xmit = qcaspi_netdev_xmit,854	.ndo_set_mac_address = eth_mac_addr,855	.ndo_tx_timeout = qcaspi_netdev_tx_timeout,856	.ndo_validate_addr = eth_validate_addr,857};858 859static void860qcaspi_netdev_setup(struct net_device *dev)861{862	struct qcaspi *qca = NULL;863 864	dev->netdev_ops = &qcaspi_netdev_ops;865	qcaspi_set_ethtool_ops(dev);866	dev->watchdog_timeo = QCASPI_TX_TIMEOUT;867	dev->priv_flags &= ~IFF_TX_SKB_SHARING;868	dev->needed_tailroom = ALIGN(QCAFRM_FOOTER_LEN + QCAFRM_MIN_LEN, 4);869	dev->needed_headroom = ALIGN(QCAFRM_HEADER_LEN, 4);870	dev->tx_queue_len = 100;871 872	/* MTU range: 46 - 1500 */873	dev->min_mtu = QCAFRM_MIN_MTU;874	dev->max_mtu = QCAFRM_MAX_MTU;875 876	qca = netdev_priv(dev);877	memset(qca, 0, sizeof(struct qcaspi));878 879	memset(&qca->txr, 0, sizeof(qca->txr));880	qca->txr.count = QCASPI_TX_RING_MAX_LEN;881}882 883static const struct of_device_id qca_spi_of_match[] = {884	{ .compatible = "qca,qca7000" },885	{ /* sentinel */ }886};887MODULE_DEVICE_TABLE(of, qca_spi_of_match);888 889static int890qca_spi_probe(struct spi_device *spi)891{892	struct qcaspi *qca = NULL;893	struct net_device *qcaspi_devs = NULL;894	u8 legacy_mode = 0;895	u16 signature;896	int ret;897 898	if (!spi->dev.of_node) {899		dev_err(&spi->dev, "Missing device tree\n");900		return -EINVAL;901	}902 903	legacy_mode = of_property_read_bool(spi->dev.of_node,904					    "qca,legacy-mode");905 906	if (qcaspi_clkspeed == 0) {907		if (spi->max_speed_hz)908			qcaspi_clkspeed = spi->max_speed_hz;909		else910			qcaspi_clkspeed = QCASPI_CLK_SPEED;911	}912 913	if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||914	    (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {915		dev_err(&spi->dev, "Invalid clkspeed: %d\n",916			qcaspi_clkspeed);917		return -EINVAL;918	}919 920	if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||921	    (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {922		dev_err(&spi->dev, "Invalid burst len: %d\n",923			qcaspi_burst_len);924		return -EINVAL;925	}926 927	if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||928	    (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {929		dev_err(&spi->dev, "Invalid pluggable: %d\n",930			qcaspi_pluggable);931		return -EINVAL;932	}933 934	if (wr_verify < QCASPI_WRITE_VERIFY_MIN ||935	    wr_verify > QCASPI_WRITE_VERIFY_MAX) {936		dev_err(&spi->dev, "Invalid write verify: %d\n",937			wr_verify);938		return -EINVAL;939	}940 941	dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",942		 QCASPI_DRV_VERSION,943		 qcaspi_clkspeed,944		 qcaspi_burst_len,945		 qcaspi_pluggable);946 947	spi->mode = SPI_MODE_3;948	spi->max_speed_hz = qcaspi_clkspeed;949	if (spi_setup(spi) < 0) {950		dev_err(&spi->dev, "Unable to setup SPI device\n");951		return -EFAULT;952	}953 954	qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));955	if (!qcaspi_devs)956		return -ENOMEM;957 958	qcaspi_netdev_setup(qcaspi_devs);959	SET_NETDEV_DEV(qcaspi_devs, &spi->dev);960 961	qca = netdev_priv(qcaspi_devs);962	if (!qca) {963		free_netdev(qcaspi_devs);964		dev_err(&spi->dev, "Fail to retrieve private structure\n");965		return -ENOMEM;966	}967	qca->net_dev = qcaspi_devs;968	qca->spi_dev = spi;969	qca->legacy_mode = legacy_mode;970 971	spi_set_drvdata(spi, qcaspi_devs);972 973	ret = devm_request_irq(&spi->dev, spi->irq, qcaspi_intr_handler,974			       IRQF_NO_AUTOEN, qca->net_dev->name, qca);975	if (ret) {976		dev_err(&spi->dev, "Unable to get IRQ %d (irqval=%d).\n",977			spi->irq, ret);978		free_netdev(qcaspi_devs);979		return ret;980	}981 982	ret = of_get_ethdev_address(spi->dev.of_node, qca->net_dev);983	if (ret) {984		eth_hw_addr_random(qca->net_dev);985		dev_info(&spi->dev, "Using random MAC address: %pM\n",986			 qca->net_dev->dev_addr);987	}988 989	netif_carrier_off(qca->net_dev);990 991	if (!qcaspi_pluggable) {992		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);993		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);994 995		if (signature != QCASPI_GOOD_SIGNATURE) {996			dev_err(&spi->dev, "Invalid signature (expected 0x%04x, read 0x%04x)\n",997				QCASPI_GOOD_SIGNATURE, signature);998			free_netdev(qcaspi_devs);999			return -EFAULT;1000		}1001	}1002 1003	if (register_netdev(qcaspi_devs)) {1004		dev_err(&spi->dev, "Unable to register net device %s\n",1005			qcaspi_devs->name);1006		free_netdev(qcaspi_devs);1007		return -EFAULT;1008	}1009 1010	qcaspi_init_device_debugfs(qca);1011 1012	return 0;1013}1014 1015static void1016qca_spi_remove(struct spi_device *spi)1017{1018	struct net_device *qcaspi_devs = spi_get_drvdata(spi);1019	struct qcaspi *qca = netdev_priv(qcaspi_devs);1020 1021	qcaspi_remove_device_debugfs(qca);1022 1023	unregister_netdev(qcaspi_devs);1024	free_netdev(qcaspi_devs);1025}1026 1027static const struct spi_device_id qca_spi_id[] = {1028	{ "qca7000", 0 },1029	{ /* sentinel */ }1030};1031MODULE_DEVICE_TABLE(spi, qca_spi_id);1032 1033static struct spi_driver qca_spi_driver = {1034	.driver	= {1035		.name	= QCASPI_DRV_NAME,1036		.of_match_table = qca_spi_of_match,1037	},1038	.id_table = qca_spi_id,1039	.probe    = qca_spi_probe,1040	.remove   = qca_spi_remove,1041};1042module_spi_driver(qca_spi_driver);1043 1044MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");1045MODULE_AUTHOR("Qualcomm Atheros Communications");1046MODULE_AUTHOR("Stefan Wahren <wahrenst@gmx.net>");1047MODULE_LICENSE("Dual BSD/GPL");1048MODULE_VERSION(QCASPI_DRV_VERSION);1049