cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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if_spi.c (31308B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *	linux/drivers/net/wireless/libertas/if_spi.c
      4 *
      5 *	Driver for Marvell SPI WLAN cards.
      6 *
      7 *	Copyright 2008 Analog Devices Inc.
      8 *
      9 *	Authors:
     10 *	Andrey Yurovsky <andrey@cozybit.com>
     11 *	Colin McCabe <colin@cozybit.com>
     12 *
     13 *	Inspired by if_sdio.c, Copyright 2007-2008 Pierre Ossman
     14 */
     15
     16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
     17
     18#include <linux/hardirq.h>
     19#include <linux/interrupt.h>
     20#include <linux/module.h>
     21#include <linux/firmware.h>
     22#include <linux/jiffies.h>
     23#include <linux/list.h>
     24#include <linux/netdevice.h>
     25#include <linux/slab.h>
     26#include <linux/spi/libertas_spi.h>
     27#include <linux/spi/spi.h>
     28
     29#include "host.h"
     30#include "decl.h"
     31#include "defs.h"
     32#include "dev.h"
     33#include "if_spi.h"
     34
     35struct if_spi_packet {
     36	struct list_head		list;
     37	u16				blen;
     38	u8				buffer[] __aligned(4);
     39};
     40
     41struct if_spi_card {
     42	struct spi_device		*spi;
     43	struct lbs_private		*priv;
     44	struct libertas_spi_platform_data *pdata;
     45
     46	/* The card ID and card revision, as reported by the hardware. */
     47	u16				card_id;
     48	u8				card_rev;
     49
     50	/* The last time that we initiated an SPU operation */
     51	unsigned long			prev_xfer_time;
     52
     53	int				use_dummy_writes;
     54	unsigned long			spu_port_delay;
     55	unsigned long			spu_reg_delay;
     56
     57	/* Handles all SPI communication (except for FW load) */
     58	struct workqueue_struct		*workqueue;
     59	struct work_struct		packet_work;
     60	struct work_struct		resume_work;
     61
     62	u8				cmd_buffer[IF_SPI_CMD_BUF_SIZE];
     63
     64	/* A buffer of incoming packets from libertas core.
     65	 * Since we can't sleep in hw_host_to_card, we have to buffer
     66	 * them. */
     67	struct list_head		cmd_packet_list;
     68	struct list_head		data_packet_list;
     69
     70	/* Protects cmd_packet_list and data_packet_list */
     71	spinlock_t			buffer_lock;
     72
     73	/* True is card suspended */
     74	u8				suspended;
     75};
     76
     77static void free_if_spi_card(struct if_spi_card *card)
     78{
     79	struct list_head *cursor, *next;
     80	struct if_spi_packet *packet;
     81
     82	list_for_each_safe(cursor, next, &card->cmd_packet_list) {
     83		packet = container_of(cursor, struct if_spi_packet, list);
     84		list_del(&packet->list);
     85		kfree(packet);
     86	}
     87	list_for_each_safe(cursor, next, &card->data_packet_list) {
     88		packet = container_of(cursor, struct if_spi_packet, list);
     89		list_del(&packet->list);
     90		kfree(packet);
     91	}
     92	kfree(card);
     93}
     94
     95#define MODEL_8385	0x04
     96#define MODEL_8686	0x0b
     97#define MODEL_8688	0x10
     98
     99static const struct lbs_fw_table fw_table[] = {
    100	{ MODEL_8385, "libertas/gspi8385_helper.bin", "libertas/gspi8385.bin" },
    101	{ MODEL_8385, "libertas/gspi8385_hlp.bin", "libertas/gspi8385.bin" },
    102	{ MODEL_8686, "libertas/gspi8686_v9_helper.bin", "libertas/gspi8686_v9.bin" },
    103	{ MODEL_8686, "libertas/gspi8686_hlp.bin", "libertas/gspi8686.bin" },
    104	{ MODEL_8688, "libertas/gspi8688_helper.bin", "libertas/gspi8688.bin" },
    105	{ 0, NULL, NULL }
    106};
    107MODULE_FIRMWARE("libertas/gspi8385_helper.bin");
    108MODULE_FIRMWARE("libertas/gspi8385_hlp.bin");
    109MODULE_FIRMWARE("libertas/gspi8385.bin");
    110MODULE_FIRMWARE("libertas/gspi8686_v9_helper.bin");
    111MODULE_FIRMWARE("libertas/gspi8686_v9.bin");
    112MODULE_FIRMWARE("libertas/gspi8686_hlp.bin");
    113MODULE_FIRMWARE("libertas/gspi8686.bin");
    114MODULE_FIRMWARE("libertas/gspi8688_helper.bin");
    115MODULE_FIRMWARE("libertas/gspi8688.bin");
    116
    117
    118/*
    119 * SPI Interface Unit Routines
    120 *
    121 * The SPU sits between the host and the WLAN module.
    122 * All communication with the firmware is through SPU transactions.
    123 *
    124 * First we have to put a SPU register name on the bus. Then we can
    125 * either read from or write to that register.
    126 *
    127 */
    128
    129static void spu_transaction_init(struct if_spi_card *card)
    130{
    131	if (!time_after(jiffies, card->prev_xfer_time + 1)) {
    132		/* Unfortunately, the SPU requires a delay between successive
    133		 * transactions. If our last transaction was more than a jiffy
    134		 * ago, we have obviously already delayed enough.
    135		 * If not, we have to busy-wait to be on the safe side. */
    136		ndelay(400);
    137	}
    138}
    139
    140static void spu_transaction_finish(struct if_spi_card *card)
    141{
    142	card->prev_xfer_time = jiffies;
    143}
    144
    145/*
    146 * Write out a byte buffer to an SPI register,
    147 * using a series of 16-bit transfers.
    148 */
    149static int spu_write(struct if_spi_card *card, u16 reg, const u8 *buf, int len)
    150{
    151	int err = 0;
    152	__le16 reg_out = cpu_to_le16(reg | IF_SPI_WRITE_OPERATION_MASK);
    153	struct spi_message m;
    154	struct spi_transfer reg_trans;
    155	struct spi_transfer data_trans;
    156
    157	spi_message_init(&m);
    158	memset(&reg_trans, 0, sizeof(reg_trans));
    159	memset(&data_trans, 0, sizeof(data_trans));
    160
    161	/* You must give an even number of bytes to the SPU, even if it
    162	 * doesn't care about the last one.  */
    163	BUG_ON(len & 0x1);
    164
    165	spu_transaction_init(card);
    166
    167	/* write SPU register index */
    168	reg_trans.tx_buf = &reg_out;
    169	reg_trans.len = sizeof(reg_out);
    170
    171	data_trans.tx_buf = buf;
    172	data_trans.len = len;
    173
    174	spi_message_add_tail(&reg_trans, &m);
    175	spi_message_add_tail(&data_trans, &m);
    176
    177	err = spi_sync(card->spi, &m);
    178	spu_transaction_finish(card);
    179	return err;
    180}
    181
    182static inline int spu_write_u16(struct if_spi_card *card, u16 reg, u16 val)
    183{
    184	__le16 buff;
    185
    186	buff = cpu_to_le16(val);
    187	return spu_write(card, reg, (u8 *)&buff, sizeof(u16));
    188}
    189
    190static inline int spu_reg_is_port_reg(u16 reg)
    191{
    192	switch (reg) {
    193	case IF_SPI_IO_RDWRPORT_REG:
    194	case IF_SPI_CMD_RDWRPORT_REG:
    195	case IF_SPI_DATA_RDWRPORT_REG:
    196		return 1;
    197	default:
    198		return 0;
    199	}
    200}
    201
    202static int spu_read(struct if_spi_card *card, u16 reg, u8 *buf, int len)
    203{
    204	unsigned int delay;
    205	int err = 0;
    206	__le16 reg_out = cpu_to_le16(reg | IF_SPI_READ_OPERATION_MASK);
    207	struct spi_message m;
    208	struct spi_transfer reg_trans;
    209	struct spi_transfer dummy_trans;
    210	struct spi_transfer data_trans;
    211
    212	/*
    213	 * You must take an even number of bytes from the SPU, even if you
    214	 * don't care about the last one.
    215	 */
    216	BUG_ON(len & 0x1);
    217
    218	spu_transaction_init(card);
    219
    220	spi_message_init(&m);
    221	memset(&reg_trans, 0, sizeof(reg_trans));
    222	memset(&dummy_trans, 0, sizeof(dummy_trans));
    223	memset(&data_trans, 0, sizeof(data_trans));
    224
    225	/* write SPU register index */
    226	reg_trans.tx_buf = &reg_out;
    227	reg_trans.len = sizeof(reg_out);
    228	spi_message_add_tail(&reg_trans, &m);
    229
    230	delay = spu_reg_is_port_reg(reg) ? card->spu_port_delay :
    231						card->spu_reg_delay;
    232	if (card->use_dummy_writes) {
    233		/* Clock in dummy cycles while the SPU fills the FIFO */
    234		dummy_trans.len = delay / 8;
    235		spi_message_add_tail(&dummy_trans, &m);
    236	} else {
    237		/* Busy-wait while the SPU fills the FIFO */
    238		reg_trans.delay.value =
    239			DIV_ROUND_UP((100 + (delay * 10)), 1000);
    240		reg_trans.delay.unit = SPI_DELAY_UNIT_USECS;
    241	}
    242
    243	/* read in data */
    244	data_trans.rx_buf = buf;
    245	data_trans.len = len;
    246	spi_message_add_tail(&data_trans, &m);
    247
    248	err = spi_sync(card->spi, &m);
    249	spu_transaction_finish(card);
    250	return err;
    251}
    252
    253/* Read 16 bits from an SPI register */
    254static inline int spu_read_u16(struct if_spi_card *card, u16 reg, u16 *val)
    255{
    256	__le16 buf;
    257	int ret;
    258
    259	ret = spu_read(card, reg, (u8 *)&buf, sizeof(buf));
    260	if (ret == 0)
    261		*val = le16_to_cpup(&buf);
    262	return ret;
    263}
    264
    265/*
    266 * Read 32 bits from an SPI register.
    267 * The low 16 bits are read first.
    268 */
    269static int spu_read_u32(struct if_spi_card *card, u16 reg, u32 *val)
    270{
    271	__le32 buf;
    272	int err;
    273
    274	err = spu_read(card, reg, (u8 *)&buf, sizeof(buf));
    275	if (!err)
    276		*val = le32_to_cpup(&buf);
    277	return err;
    278}
    279
    280/*
    281 * Keep reading 16 bits from an SPI register until you get the correct result.
    282 *
    283 * If mask = 0, the correct result is any non-zero number.
    284 * If mask != 0, the correct result is any number where
    285 * number & target_mask == target
    286 *
    287 * Returns -ETIMEDOUT if a second passes without the correct result.
    288 */
    289static int spu_wait_for_u16(struct if_spi_card *card, u16 reg,
    290			u16 target_mask, u16 target)
    291{
    292	int err;
    293	unsigned long timeout = jiffies + 5*HZ;
    294	while (1) {
    295		u16 val;
    296		err = spu_read_u16(card, reg, &val);
    297		if (err)
    298			return err;
    299		if (target_mask) {
    300			if ((val & target_mask) == target)
    301				return 0;
    302		} else {
    303			if (val)
    304				return 0;
    305		}
    306		udelay(100);
    307		if (time_after(jiffies, timeout)) {
    308			pr_err("%s: timeout with val=%02x, target_mask=%02x, target=%02x\n",
    309			       __func__, val, target_mask, target);
    310			return -ETIMEDOUT;
    311		}
    312	}
    313}
    314
    315/*
    316 * Read 16 bits from an SPI register until you receive a specific value.
    317 * Returns -ETIMEDOUT if a 4 tries pass without success.
    318 */
    319static int spu_wait_for_u32(struct if_spi_card *card, u32 reg, u32 target)
    320{
    321	int err, try;
    322	for (try = 0; try < 4; ++try) {
    323		u32 val = 0;
    324		err = spu_read_u32(card, reg, &val);
    325		if (err)
    326			return err;
    327		if (val == target)
    328			return 0;
    329		mdelay(100);
    330	}
    331	return -ETIMEDOUT;
    332}
    333
    334static int spu_set_interrupt_mode(struct if_spi_card *card,
    335			   int suppress_host_int,
    336			   int auto_int)
    337{
    338	int err = 0;
    339
    340	/*
    341	 * We can suppress a host interrupt by clearing the appropriate
    342	 * bit in the "host interrupt status mask" register
    343	 */
    344	if (suppress_host_int) {
    345		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_MASK_REG, 0);
    346		if (err)
    347			return err;
    348	} else {
    349		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_MASK_REG,
    350			      IF_SPI_HISM_TX_DOWNLOAD_RDY |
    351			      IF_SPI_HISM_RX_UPLOAD_RDY |
    352			      IF_SPI_HISM_CMD_DOWNLOAD_RDY |
    353			      IF_SPI_HISM_CARDEVENT |
    354			      IF_SPI_HISM_CMD_UPLOAD_RDY);
    355		if (err)
    356			return err;
    357	}
    358
    359	/*
    360	 * If auto-interrupts are on, the completion of certain transactions
    361	 * will trigger an interrupt automatically. If auto-interrupts
    362	 * are off, we need to set the "Card Interrupt Cause" register to
    363	 * trigger a card interrupt.
    364	 */
    365	if (auto_int) {
    366		err = spu_write_u16(card, IF_SPI_HOST_INT_CTRL_REG,
    367				IF_SPI_HICT_TX_DOWNLOAD_OVER_AUTO |
    368				IF_SPI_HICT_RX_UPLOAD_OVER_AUTO |
    369				IF_SPI_HICT_CMD_DOWNLOAD_OVER_AUTO |
    370				IF_SPI_HICT_CMD_UPLOAD_OVER_AUTO);
    371		if (err)
    372			return err;
    373	} else {
    374		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_MASK_REG, 0);
    375		if (err)
    376			return err;
    377	}
    378	return err;
    379}
    380
    381static int spu_get_chip_revision(struct if_spi_card *card,
    382				  u16 *card_id, u8 *card_rev)
    383{
    384	int err = 0;
    385	u32 dev_ctrl;
    386	err = spu_read_u32(card, IF_SPI_DEVICEID_CTRL_REG, &dev_ctrl);
    387	if (err)
    388		return err;
    389	*card_id = IF_SPI_DEVICEID_CTRL_REG_TO_CARD_ID(dev_ctrl);
    390	*card_rev = IF_SPI_DEVICEID_CTRL_REG_TO_CARD_REV(dev_ctrl);
    391	return err;
    392}
    393
    394static int spu_set_bus_mode(struct if_spi_card *card, u16 mode)
    395{
    396	int err = 0;
    397	u16 rval;
    398	/* set bus mode */
    399	err = spu_write_u16(card, IF_SPI_SPU_BUS_MODE_REG, mode);
    400	if (err)
    401		return err;
    402	/* Check that we were able to read back what we just wrote. */
    403	err = spu_read_u16(card, IF_SPI_SPU_BUS_MODE_REG, &rval);
    404	if (err)
    405		return err;
    406	if ((rval & 0xF) != mode) {
    407		pr_err("Can't read bus mode register\n");
    408		return -EIO;
    409	}
    410	return 0;
    411}
    412
    413static int spu_init(struct if_spi_card *card, int use_dummy_writes)
    414{
    415	int err = 0;
    416	u32 delay;
    417
    418	/*
    419	 * We have to start up in timed delay mode so that we can safely
    420	 * read the Delay Read Register.
    421	 */
    422	card->use_dummy_writes = 0;
    423	err = spu_set_bus_mode(card,
    424				IF_SPI_BUS_MODE_SPI_CLOCK_PHASE_RISING |
    425				IF_SPI_BUS_MODE_DELAY_METHOD_TIMED |
    426				IF_SPI_BUS_MODE_16_BIT_ADDRESS_16_BIT_DATA);
    427	if (err)
    428		return err;
    429	card->spu_port_delay = 1000;
    430	card->spu_reg_delay = 1000;
    431	err = spu_read_u32(card, IF_SPI_DELAY_READ_REG, &delay);
    432	if (err)
    433		return err;
    434	card->spu_port_delay = delay & 0x0000ffff;
    435	card->spu_reg_delay = (delay & 0xffff0000) >> 16;
    436
    437	/* If dummy clock delay mode has been requested, switch to it now */
    438	if (use_dummy_writes) {
    439		card->use_dummy_writes = 1;
    440		err = spu_set_bus_mode(card,
    441				IF_SPI_BUS_MODE_SPI_CLOCK_PHASE_RISING |
    442				IF_SPI_BUS_MODE_DELAY_METHOD_DUMMY_CLOCK |
    443				IF_SPI_BUS_MODE_16_BIT_ADDRESS_16_BIT_DATA);
    444		if (err)
    445			return err;
    446	}
    447
    448	lbs_deb_spi("Initialized SPU unit. "
    449		    "spu_port_delay=0x%04lx, spu_reg_delay=0x%04lx\n",
    450		    card->spu_port_delay, card->spu_reg_delay);
    451	return err;
    452}
    453
    454/*
    455 * Firmware Loading
    456 */
    457
    458static int if_spi_prog_helper_firmware(struct if_spi_card *card,
    459					const struct firmware *firmware)
    460{
    461	int err = 0;
    462	int bytes_remaining;
    463	const u8 *fw;
    464	u8 temp[HELPER_FW_LOAD_CHUNK_SZ];
    465
    466	err = spu_set_interrupt_mode(card, 1, 0);
    467	if (err)
    468		goto out;
    469
    470	bytes_remaining = firmware->size;
    471	fw = firmware->data;
    472
    473	/* Load helper firmware image */
    474	while (bytes_remaining > 0) {
    475		/*
    476		 * Scratch pad 1 should contain the number of bytes we
    477		 * want to download to the firmware
    478		 */
    479		err = spu_write_u16(card, IF_SPI_SCRATCH_1_REG,
    480					HELPER_FW_LOAD_CHUNK_SZ);
    481		if (err)
    482			goto out;
    483
    484		err = spu_wait_for_u16(card, IF_SPI_HOST_INT_STATUS_REG,
    485					IF_SPI_HIST_CMD_DOWNLOAD_RDY,
    486					IF_SPI_HIST_CMD_DOWNLOAD_RDY);
    487		if (err)
    488			goto out;
    489
    490		/*
    491		 * Feed the data into the command read/write port reg
    492		 * in chunks of 64 bytes
    493		 */
    494		memset(temp, 0, sizeof(temp));
    495		memcpy(temp, fw,
    496		       min(bytes_remaining, HELPER_FW_LOAD_CHUNK_SZ));
    497		mdelay(10);
    498		err = spu_write(card, IF_SPI_CMD_RDWRPORT_REG,
    499					temp, HELPER_FW_LOAD_CHUNK_SZ);
    500		if (err)
    501			goto out;
    502
    503		/* Interrupt the boot code */
    504		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG, 0);
    505		if (err)
    506			goto out;
    507		err = spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG,
    508				       IF_SPI_CIC_CMD_DOWNLOAD_OVER);
    509		if (err)
    510			goto out;
    511		bytes_remaining -= HELPER_FW_LOAD_CHUNK_SZ;
    512		fw += HELPER_FW_LOAD_CHUNK_SZ;
    513	}
    514
    515	/*
    516	 * Once the helper / single stage firmware download is complete,
    517	 * write 0 to scratch pad 1 and interrupt the
    518	 * bootloader. This completes the helper download.
    519	 */
    520	err = spu_write_u16(card, IF_SPI_SCRATCH_1_REG, FIRMWARE_DNLD_OK);
    521	if (err)
    522		goto out;
    523	err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG, 0);
    524	if (err)
    525		goto out;
    526	err = spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG,
    527				IF_SPI_CIC_CMD_DOWNLOAD_OVER);
    528out:
    529	if (err)
    530		pr_err("failed to load helper firmware (err=%d)\n", err);
    531
    532	return err;
    533}
    534
    535/*
    536 * Returns the length of the next packet the firmware expects us to send.
    537 * Sets crc_err if the previous transfer had a CRC error.
    538 */
    539static int if_spi_prog_main_firmware_check_len(struct if_spi_card *card,
    540						int *crc_err)
    541{
    542	u16 len;
    543	int err = 0;
    544
    545	/*
    546	 * wait until the host interrupt status register indicates
    547	 * that we are ready to download
    548	 */
    549	err = spu_wait_for_u16(card, IF_SPI_HOST_INT_STATUS_REG,
    550				IF_SPI_HIST_CMD_DOWNLOAD_RDY,
    551				IF_SPI_HIST_CMD_DOWNLOAD_RDY);
    552	if (err) {
    553		pr_err("timed out waiting for host_int_status\n");
    554		return err;
    555	}
    556
    557	/* Ask the device how many bytes of firmware it wants. */
    558	err = spu_read_u16(card, IF_SPI_SCRATCH_1_REG, &len);
    559	if (err)
    560		return err;
    561
    562	if (len > IF_SPI_CMD_BUF_SIZE) {
    563		pr_err("firmware load device requested a larger transfer than we are prepared to handle (len = %d)\n",
    564		       len);
    565		return -EIO;
    566	}
    567	if (len & 0x1) {
    568		lbs_deb_spi("%s: crc error\n", __func__);
    569		len &= ~0x1;
    570		*crc_err = 1;
    571	} else
    572		*crc_err = 0;
    573
    574	return len;
    575}
    576
    577static int if_spi_prog_main_firmware(struct if_spi_card *card,
    578					const struct firmware *firmware)
    579{
    580	struct lbs_private *priv = card->priv;
    581	int len, prev_len;
    582	int bytes, crc_err = 0, err = 0;
    583	const u8 *fw;
    584	u16 num_crc_errs;
    585
    586	err = spu_set_interrupt_mode(card, 1, 0);
    587	if (err)
    588		goto out;
    589
    590	err = spu_wait_for_u16(card, IF_SPI_SCRATCH_1_REG, 0, 0);
    591	if (err) {
    592		netdev_err(priv->dev,
    593			   "%s: timed out waiting for initial scratch reg = 0\n",
    594			   __func__);
    595		goto out;
    596	}
    597
    598	num_crc_errs = 0;
    599	prev_len = 0;
    600	bytes = firmware->size;
    601	fw = firmware->data;
    602	while ((len = if_spi_prog_main_firmware_check_len(card, &crc_err))) {
    603		if (len < 0) {
    604			err = len;
    605			goto out;
    606		}
    607		if (bytes < 0) {
    608			/*
    609			 * If there are no more bytes left, we would normally
    610			 * expect to have terminated with len = 0
    611			 */
    612			netdev_err(priv->dev,
    613				   "Firmware load wants more bytes than we have to offer.\n");
    614			break;
    615		}
    616		if (crc_err) {
    617			/* Previous transfer failed. */
    618			if (++num_crc_errs > MAX_MAIN_FW_LOAD_CRC_ERR) {
    619				pr_err("Too many CRC errors encountered in firmware load.\n");
    620				err = -EIO;
    621				goto out;
    622			}
    623		} else {
    624			/* Previous transfer succeeded. Advance counters. */
    625			bytes -= prev_len;
    626			fw += prev_len;
    627		}
    628		if (bytes < len) {
    629			memset(card->cmd_buffer, 0, len);
    630			memcpy(card->cmd_buffer, fw, bytes);
    631		} else
    632			memcpy(card->cmd_buffer, fw, len);
    633
    634		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG, 0);
    635		if (err)
    636			goto out;
    637		err = spu_write(card, IF_SPI_CMD_RDWRPORT_REG,
    638				card->cmd_buffer, len);
    639		if (err)
    640			goto out;
    641		err = spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG ,
    642					IF_SPI_CIC_CMD_DOWNLOAD_OVER);
    643		if (err)
    644			goto out;
    645		prev_len = len;
    646	}
    647	if (bytes > prev_len) {
    648		pr_err("firmware load wants fewer bytes than we have to offer\n");
    649	}
    650
    651	/* Confirm firmware download */
    652	err = spu_wait_for_u32(card, IF_SPI_SCRATCH_4_REG,
    653					SUCCESSFUL_FW_DOWNLOAD_MAGIC);
    654	if (err) {
    655		pr_err("failed to confirm the firmware download\n");
    656		goto out;
    657	}
    658
    659out:
    660	if (err)
    661		pr_err("failed to load firmware (err=%d)\n", err);
    662
    663	return err;
    664}
    665
    666/*
    667 * SPI Transfer Thread
    668 *
    669 * The SPI worker handles all SPI transfers, so there is no need for a lock.
    670 */
    671
    672/* Move a command from the card to the host */
    673static int if_spi_c2h_cmd(struct if_spi_card *card)
    674{
    675	struct lbs_private *priv = card->priv;
    676	unsigned long flags;
    677	int err = 0;
    678	u16 len;
    679	u8 i;
    680
    681	/*
    682	 * We need a buffer big enough to handle whatever people send to
    683	 * hw_host_to_card
    684	 */
    685	BUILD_BUG_ON(IF_SPI_CMD_BUF_SIZE < LBS_CMD_BUFFER_SIZE);
    686	BUILD_BUG_ON(IF_SPI_CMD_BUF_SIZE < LBS_UPLD_SIZE);
    687
    688	/*
    689	 * It's just annoying if the buffer size isn't a multiple of 4, because
    690	 * then we might have len < IF_SPI_CMD_BUF_SIZE but
    691	 * ALIGN(len, 4) > IF_SPI_CMD_BUF_SIZE
    692	 */
    693	BUILD_BUG_ON(IF_SPI_CMD_BUF_SIZE % 4 != 0);
    694
    695	/* How many bytes are there to read? */
    696	err = spu_read_u16(card, IF_SPI_SCRATCH_2_REG, &len);
    697	if (err)
    698		goto out;
    699	if (!len) {
    700		netdev_err(priv->dev, "%s: error: card has no data for host\n",
    701			   __func__);
    702		err = -EINVAL;
    703		goto out;
    704	} else if (len > IF_SPI_CMD_BUF_SIZE) {
    705		netdev_err(priv->dev,
    706			   "%s: error: response packet too large: %d bytes, but maximum is %d\n",
    707			   __func__, len, IF_SPI_CMD_BUF_SIZE);
    708		err = -EINVAL;
    709		goto out;
    710	}
    711
    712	/* Read the data from the WLAN module into our command buffer */
    713	err = spu_read(card, IF_SPI_CMD_RDWRPORT_REG,
    714				card->cmd_buffer, ALIGN(len, 4));
    715	if (err)
    716		goto out;
    717
    718	spin_lock_irqsave(&priv->driver_lock, flags);
    719	i = (priv->resp_idx == 0) ? 1 : 0;
    720	BUG_ON(priv->resp_len[i]);
    721	priv->resp_len[i] = len;
    722	memcpy(priv->resp_buf[i], card->cmd_buffer, len);
    723	lbs_notify_command_response(priv, i);
    724	spin_unlock_irqrestore(&priv->driver_lock, flags);
    725
    726out:
    727	if (err)
    728		netdev_err(priv->dev, "%s: err=%d\n", __func__, err);
    729
    730	return err;
    731}
    732
    733/* Move data from the card to the host */
    734static int if_spi_c2h_data(struct if_spi_card *card)
    735{
    736	struct lbs_private *priv = card->priv;
    737	struct sk_buff *skb;
    738	char *data;
    739	u16 len;
    740	int err = 0;
    741
    742	/* How many bytes are there to read? */
    743	err = spu_read_u16(card, IF_SPI_SCRATCH_1_REG, &len);
    744	if (err)
    745		goto out;
    746	if (!len) {
    747		netdev_err(priv->dev, "%s: error: card has no data for host\n",
    748			   __func__);
    749		err = -EINVAL;
    750		goto out;
    751	} else if (len > MRVDRV_ETH_RX_PACKET_BUFFER_SIZE) {
    752		netdev_err(priv->dev,
    753			   "%s: error: card has %d bytes of data, but our maximum skb size is %zu\n",
    754			   __func__, len, MRVDRV_ETH_RX_PACKET_BUFFER_SIZE);
    755		err = -EINVAL;
    756		goto out;
    757	}
    758
    759	/* TODO: should we allocate a smaller skb if we have less data? */
    760	skb = dev_alloc_skb(MRVDRV_ETH_RX_PACKET_BUFFER_SIZE);
    761	if (!skb) {
    762		err = -ENOBUFS;
    763		goto out;
    764	}
    765	skb_reserve(skb, IPFIELD_ALIGN_OFFSET);
    766	data = skb_put(skb, len);
    767
    768	/* Read the data from the WLAN module into our skb... */
    769	err = spu_read(card, IF_SPI_DATA_RDWRPORT_REG, data, ALIGN(len, 4));
    770	if (err) {
    771		dev_kfree_skb(skb);
    772		goto out;
    773	}
    774
    775	/* pass the SKB to libertas */
    776	err = lbs_process_rxed_packet(card->priv, skb);
    777	/* lbs_process_rxed_packet() consumes the skb */
    778
    779out:
    780	if (err)
    781		netdev_err(priv->dev, "%s: err=%d\n", __func__, err);
    782
    783	return err;
    784}
    785
    786/* Move data or a command from the host to the card. */
    787static void if_spi_h2c(struct if_spi_card *card,
    788			struct if_spi_packet *packet, int type)
    789{
    790	struct lbs_private *priv = card->priv;
    791	int err = 0;
    792	u16 port_reg;
    793
    794	switch (type) {
    795	case MVMS_DAT:
    796		port_reg = IF_SPI_DATA_RDWRPORT_REG;
    797		break;
    798	case MVMS_CMD:
    799		port_reg = IF_SPI_CMD_RDWRPORT_REG;
    800		break;
    801	default:
    802		netdev_err(priv->dev, "can't transfer buffer of type %d\n",
    803			   type);
    804		err = -EINVAL;
    805		goto out;
    806	}
    807
    808	/* Write the data to the card */
    809	err = spu_write(card, port_reg, packet->buffer, packet->blen);
    810	if (err)
    811		goto out;
    812
    813out:
    814	kfree(packet);
    815
    816	if (err)
    817		netdev_err(priv->dev, "%s: error %d\n", __func__, err);
    818}
    819
    820/* Inform the host about a card event */
    821static void if_spi_e2h(struct if_spi_card *card)
    822{
    823	int err = 0;
    824	u32 cause;
    825	struct lbs_private *priv = card->priv;
    826
    827	err = spu_read_u32(card, IF_SPI_SCRATCH_3_REG, &cause);
    828	if (err)
    829		goto out;
    830
    831	/* re-enable the card event interrupt */
    832	spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG,
    833			~IF_SPI_HICU_CARD_EVENT);
    834
    835	/* generate a card interrupt */
    836	spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG, IF_SPI_CIC_HOST_EVENT);
    837
    838	lbs_queue_event(priv, cause & 0xff);
    839out:
    840	if (err)
    841		netdev_err(priv->dev, "%s: error %d\n", __func__, err);
    842}
    843
    844static void if_spi_host_to_card_worker(struct work_struct *work)
    845{
    846	int err;
    847	struct if_spi_card *card;
    848	u16 hiStatus;
    849	unsigned long flags;
    850	struct if_spi_packet *packet;
    851	struct lbs_private *priv;
    852
    853	card = container_of(work, struct if_spi_card, packet_work);
    854	priv = card->priv;
    855
    856	/*
    857	 * Read the host interrupt status register to see what we
    858	 * can do.
    859	 */
    860	err = spu_read_u16(card, IF_SPI_HOST_INT_STATUS_REG,
    861				&hiStatus);
    862	if (err) {
    863		netdev_err(priv->dev, "I/O error\n");
    864		goto err;
    865	}
    866
    867	if (hiStatus & IF_SPI_HIST_CMD_UPLOAD_RDY) {
    868		err = if_spi_c2h_cmd(card);
    869		if (err)
    870			goto err;
    871	}
    872	if (hiStatus & IF_SPI_HIST_RX_UPLOAD_RDY) {
    873		err = if_spi_c2h_data(card);
    874		if (err)
    875			goto err;
    876	}
    877
    878	/*
    879	 * workaround: in PS mode, the card does not set the Command
    880	 * Download Ready bit, but it sets TX Download Ready.
    881	 */
    882	if (hiStatus & IF_SPI_HIST_CMD_DOWNLOAD_RDY ||
    883	   (card->priv->psstate != PS_STATE_FULL_POWER &&
    884	    (hiStatus & IF_SPI_HIST_TX_DOWNLOAD_RDY))) {
    885		/*
    886		 * This means two things. First of all,
    887		 * if there was a previous command sent, the card has
    888		 * successfully received it.
    889		 * Secondly, it is now ready to download another
    890		 * command.
    891		 */
    892		lbs_host_to_card_done(card->priv);
    893
    894		/* Do we have any command packets from the host to send? */
    895		packet = NULL;
    896		spin_lock_irqsave(&card->buffer_lock, flags);
    897		if (!list_empty(&card->cmd_packet_list)) {
    898			packet = (struct if_spi_packet *)(card->
    899					cmd_packet_list.next);
    900			list_del(&packet->list);
    901		}
    902		spin_unlock_irqrestore(&card->buffer_lock, flags);
    903
    904		if (packet)
    905			if_spi_h2c(card, packet, MVMS_CMD);
    906	}
    907	if (hiStatus & IF_SPI_HIST_TX_DOWNLOAD_RDY) {
    908		/* Do we have any data packets from the host to send? */
    909		packet = NULL;
    910		spin_lock_irqsave(&card->buffer_lock, flags);
    911		if (!list_empty(&card->data_packet_list)) {
    912			packet = (struct if_spi_packet *)(card->
    913					data_packet_list.next);
    914			list_del(&packet->list);
    915		}
    916		spin_unlock_irqrestore(&card->buffer_lock, flags);
    917
    918		if (packet)
    919			if_spi_h2c(card, packet, MVMS_DAT);
    920	}
    921	if (hiStatus & IF_SPI_HIST_CARD_EVENT)
    922		if_spi_e2h(card);
    923
    924err:
    925	if (err)
    926		netdev_err(priv->dev, "%s: got error %d\n", __func__, err);
    927}
    928
    929/*
    930 * Host to Card
    931 *
    932 * Called from Libertas to transfer some data to the WLAN device
    933 * We can't sleep here.
    934 */
    935static int if_spi_host_to_card(struct lbs_private *priv,
    936				u8 type, u8 *buf, u16 nb)
    937{
    938	int err = 0;
    939	unsigned long flags;
    940	struct if_spi_card *card = priv->card;
    941	struct if_spi_packet *packet;
    942	u16 blen;
    943
    944	if (nb == 0) {
    945		netdev_err(priv->dev, "%s: invalid size requested: %d\n",
    946			   __func__, nb);
    947		err = -EINVAL;
    948		goto out;
    949	}
    950	blen = ALIGN(nb, 4);
    951	packet = kzalloc(sizeof(struct if_spi_packet) + blen, GFP_ATOMIC);
    952	if (!packet) {
    953		err = -ENOMEM;
    954		goto out;
    955	}
    956	packet->blen = blen;
    957	memcpy(packet->buffer, buf, nb);
    958	memset(packet->buffer + nb, 0, blen - nb);
    959
    960	switch (type) {
    961	case MVMS_CMD:
    962		priv->dnld_sent = DNLD_CMD_SENT;
    963		spin_lock_irqsave(&card->buffer_lock, flags);
    964		list_add_tail(&packet->list, &card->cmd_packet_list);
    965		spin_unlock_irqrestore(&card->buffer_lock, flags);
    966		break;
    967	case MVMS_DAT:
    968		priv->dnld_sent = DNLD_DATA_SENT;
    969		spin_lock_irqsave(&card->buffer_lock, flags);
    970		list_add_tail(&packet->list, &card->data_packet_list);
    971		spin_unlock_irqrestore(&card->buffer_lock, flags);
    972		break;
    973	default:
    974		kfree(packet);
    975		netdev_err(priv->dev, "can't transfer buffer of type %d\n",
    976			   type);
    977		err = -EINVAL;
    978		break;
    979	}
    980
    981	/* Queue spi xfer work */
    982	queue_work(card->workqueue, &card->packet_work);
    983out:
    984	return err;
    985}
    986
    987/*
    988 * Host Interrupts
    989 *
    990 * Service incoming interrupts from the WLAN device. We can't sleep here, so
    991 * don't try to talk on the SPI bus, just queue the SPI xfer work.
    992 */
    993static irqreturn_t if_spi_host_interrupt(int irq, void *dev_id)
    994{
    995	struct if_spi_card *card = dev_id;
    996
    997	queue_work(card->workqueue, &card->packet_work);
    998
    999	return IRQ_HANDLED;
   1000}
   1001
   1002/*
   1003 * SPI callbacks
   1004 */
   1005
   1006static int if_spi_init_card(struct if_spi_card *card)
   1007{
   1008	struct lbs_private *priv = card->priv;
   1009	int err, i;
   1010	u32 scratch;
   1011	const struct firmware *helper = NULL;
   1012	const struct firmware *mainfw = NULL;
   1013
   1014	err = spu_init(card, card->pdata->use_dummy_writes);
   1015	if (err)
   1016		goto out;
   1017	err = spu_get_chip_revision(card, &card->card_id, &card->card_rev);
   1018	if (err)
   1019		goto out;
   1020
   1021	err = spu_read_u32(card, IF_SPI_SCRATCH_4_REG, &scratch);
   1022	if (err)
   1023		goto out;
   1024	if (scratch == SUCCESSFUL_FW_DOWNLOAD_MAGIC)
   1025		lbs_deb_spi("Firmware is already loaded for "
   1026			    "Marvell WLAN 802.11 adapter\n");
   1027	else {
   1028		/* Check if we support this card */
   1029		for (i = 0; i < ARRAY_SIZE(fw_table); i++) {
   1030			if (card->card_id == fw_table[i].model)
   1031				break;
   1032		}
   1033		if (i == ARRAY_SIZE(fw_table)) {
   1034			netdev_err(priv->dev, "Unsupported chip_id: 0x%02x\n",
   1035				   card->card_id);
   1036			err = -ENODEV;
   1037			goto out;
   1038		}
   1039
   1040		err = lbs_get_firmware(&card->spi->dev, card->card_id,
   1041					&fw_table[0], &helper, &mainfw);
   1042		if (err) {
   1043			netdev_err(priv->dev, "failed to find firmware (%d)\n",
   1044				   err);
   1045			goto out;
   1046		}
   1047
   1048		lbs_deb_spi("Initializing FW for Marvell WLAN 802.11 adapter "
   1049				"(chip_id = 0x%04x, chip_rev = 0x%02x) "
   1050				"attached to SPI bus_num %d, chip_select %d. "
   1051				"spi->max_speed_hz=%d\n",
   1052				card->card_id, card->card_rev,
   1053				card->spi->master->bus_num,
   1054				card->spi->chip_select,
   1055				card->spi->max_speed_hz);
   1056		err = if_spi_prog_helper_firmware(card, helper);
   1057		if (err)
   1058			goto out;
   1059		err = if_spi_prog_main_firmware(card, mainfw);
   1060		if (err)
   1061			goto out;
   1062		lbs_deb_spi("loaded FW for Marvell WLAN 802.11 adapter\n");
   1063	}
   1064
   1065	err = spu_set_interrupt_mode(card, 0, 1);
   1066	if (err)
   1067		goto out;
   1068
   1069out:
   1070	return err;
   1071}
   1072
   1073static void if_spi_resume_worker(struct work_struct *work)
   1074{
   1075	struct if_spi_card *card;
   1076
   1077	card = container_of(work, struct if_spi_card, resume_work);
   1078
   1079	if (card->suspended) {
   1080		if (card->pdata->setup)
   1081			card->pdata->setup(card->spi);
   1082
   1083		/* Init card ... */
   1084		if_spi_init_card(card);
   1085
   1086		enable_irq(card->spi->irq);
   1087
   1088		/* And resume it ... */
   1089		lbs_resume(card->priv);
   1090
   1091		card->suspended = 0;
   1092	}
   1093}
   1094
   1095static int if_spi_probe(struct spi_device *spi)
   1096{
   1097	struct if_spi_card *card;
   1098	struct lbs_private *priv = NULL;
   1099	struct libertas_spi_platform_data *pdata = dev_get_platdata(&spi->dev);
   1100	int err = 0;
   1101
   1102	if (!pdata) {
   1103		err = -EINVAL;
   1104		goto out;
   1105	}
   1106
   1107	if (pdata->setup) {
   1108		err = pdata->setup(spi);
   1109		if (err)
   1110			goto out;
   1111	}
   1112
   1113	/* Allocate card structure to represent this specific device */
   1114	card = kzalloc(sizeof(struct if_spi_card), GFP_KERNEL);
   1115	if (!card) {
   1116		err = -ENOMEM;
   1117		goto teardown;
   1118	}
   1119	spi_set_drvdata(spi, card);
   1120	card->pdata = pdata;
   1121	card->spi = spi;
   1122	card->prev_xfer_time = jiffies;
   1123
   1124	INIT_LIST_HEAD(&card->cmd_packet_list);
   1125	INIT_LIST_HEAD(&card->data_packet_list);
   1126	spin_lock_init(&card->buffer_lock);
   1127
   1128	/* Initialize the SPI Interface Unit */
   1129
   1130	/* Firmware load */
   1131	err = if_spi_init_card(card);
   1132	if (err)
   1133		goto free_card;
   1134
   1135	/*
   1136	 * Register our card with libertas.
   1137	 * This will call alloc_etherdev.
   1138	 */
   1139	priv = lbs_add_card(card, &spi->dev);
   1140	if (IS_ERR(priv)) {
   1141		err = PTR_ERR(priv);
   1142		goto free_card;
   1143	}
   1144	card->priv = priv;
   1145	priv->setup_fw_on_resume = 1;
   1146	priv->card = card;
   1147	priv->hw_host_to_card = if_spi_host_to_card;
   1148	priv->enter_deep_sleep = NULL;
   1149	priv->exit_deep_sleep = NULL;
   1150	priv->reset_deep_sleep_wakeup = NULL;
   1151	priv->fw_ready = 1;
   1152
   1153	/* Initialize interrupt handling stuff. */
   1154	card->workqueue = alloc_workqueue("libertas_spi", WQ_MEM_RECLAIM, 0);
   1155	if (!card->workqueue) {
   1156		err = -ENOMEM;
   1157		goto remove_card;
   1158	}
   1159	INIT_WORK(&card->packet_work, if_spi_host_to_card_worker);
   1160	INIT_WORK(&card->resume_work, if_spi_resume_worker);
   1161
   1162	err = request_irq(spi->irq, if_spi_host_interrupt,
   1163			IRQF_TRIGGER_FALLING, "libertas_spi", card);
   1164	if (err) {
   1165		pr_err("can't get host irq line-- request_irq failed\n");
   1166		goto terminate_workqueue;
   1167	}
   1168
   1169	/*
   1170	 * Start the card.
   1171	 * This will call register_netdev, and we'll start
   1172	 * getting interrupts...
   1173	 */
   1174	err = lbs_start_card(priv);
   1175	if (err)
   1176		goto release_irq;
   1177
   1178	lbs_deb_spi("Finished initializing WLAN module.\n");
   1179
   1180	/* successful exit */
   1181	goto out;
   1182
   1183release_irq:
   1184	free_irq(spi->irq, card);
   1185terminate_workqueue:
   1186	destroy_workqueue(card->workqueue);
   1187remove_card:
   1188	lbs_remove_card(priv); /* will call free_netdev */
   1189free_card:
   1190	free_if_spi_card(card);
   1191teardown:
   1192	if (pdata->teardown)
   1193		pdata->teardown(spi);
   1194out:
   1195	return err;
   1196}
   1197
   1198static void libertas_spi_remove(struct spi_device *spi)
   1199{
   1200	struct if_spi_card *card = spi_get_drvdata(spi);
   1201	struct lbs_private *priv = card->priv;
   1202
   1203	lbs_deb_spi("libertas_spi_remove\n");
   1204
   1205	cancel_work_sync(&card->resume_work);
   1206
   1207	lbs_stop_card(priv);
   1208	lbs_remove_card(priv); /* will call free_netdev */
   1209
   1210	free_irq(spi->irq, card);
   1211	destroy_workqueue(card->workqueue);
   1212	if (card->pdata->teardown)
   1213		card->pdata->teardown(spi);
   1214	free_if_spi_card(card);
   1215}
   1216
   1217static int if_spi_suspend(struct device *dev)
   1218{
   1219	struct spi_device *spi = to_spi_device(dev);
   1220	struct if_spi_card *card = spi_get_drvdata(spi);
   1221
   1222	if (!card->suspended) {
   1223		lbs_suspend(card->priv);
   1224		flush_workqueue(card->workqueue);
   1225		disable_irq(spi->irq);
   1226
   1227		if (card->pdata->teardown)
   1228			card->pdata->teardown(spi);
   1229		card->suspended = 1;
   1230	}
   1231
   1232	return 0;
   1233}
   1234
   1235static int if_spi_resume(struct device *dev)
   1236{
   1237	struct spi_device *spi = to_spi_device(dev);
   1238	struct if_spi_card *card = spi_get_drvdata(spi);
   1239
   1240	/* Schedule delayed work */
   1241	schedule_work(&card->resume_work);
   1242
   1243	return 0;
   1244}
   1245
   1246static const struct dev_pm_ops if_spi_pm_ops = {
   1247	.suspend	= if_spi_suspend,
   1248	.resume		= if_spi_resume,
   1249};
   1250
   1251static struct spi_driver libertas_spi_driver = {
   1252	.probe	= if_spi_probe,
   1253	.remove = libertas_spi_remove,
   1254	.driver = {
   1255		.name	= "libertas_spi",
   1256		.pm	= &if_spi_pm_ops,
   1257	},
   1258};
   1259
   1260/*
   1261 * Module functions
   1262 */
   1263
   1264static int __init if_spi_init_module(void)
   1265{
   1266	int ret = 0;
   1267
   1268	printk(KERN_INFO "libertas_spi: Libertas SPI driver\n");
   1269	ret = spi_register_driver(&libertas_spi_driver);
   1270
   1271	return ret;
   1272}
   1273
   1274static void __exit if_spi_exit_module(void)
   1275{
   1276	spi_unregister_driver(&libertas_spi_driver);
   1277}
   1278
   1279module_init(if_spi_init_module);
   1280module_exit(if_spi_exit_module);
   1281
   1282MODULE_DESCRIPTION("Libertas SPI WLAN Driver");
   1283MODULE_AUTHOR("Andrey Yurovsky <andrey@cozybit.com>, "
   1284	      "Colin McCabe <colin@cozybit.com>");
   1285MODULE_LICENSE("GPL");
   1286MODULE_ALIAS("spi:libertas_spi");