brintos

brintos / linux-shallow public Read only

0
0
Text · 29.8 KiB · 1d4c731 Raw
1283 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/* imm.c   --  low level driver for the IOMEGA MatchMaker3 * parallel port SCSI host adapter.4 * 5 * (The IMM is the embedded controller in the ZIP Plus drive.)6 * 7 * My unofficial company acronym list is 21 pages long:8 *      FLA:    Four letter acronym with built in facility for9 *              future expansion to five letters.10 */11 12#include <linux/init.h>13#include <linux/kernel.h>14#include <linux/module.h>15#include <linux/blkdev.h>16#include <linux/parport.h>17#include <linux/workqueue.h>18#include <linux/delay.h>19#include <linux/slab.h>20#include <asm/io.h>21 22#include <scsi/scsi.h>23#include <scsi/scsi_cmnd.h>24#include <scsi/scsi_device.h>25#include <scsi/scsi_host.h>26 27/* The following #define is to avoid a clash with hosts.c */28#define IMM_PROBE_SPP   0x000129#define IMM_PROBE_PS2   0x000230#define IMM_PROBE_ECR   0x001031#define IMM_PROBE_EPP17 0x010032#define IMM_PROBE_EPP19 0x020033 34 35typedef struct {36	struct pardevice *dev;	/* Parport device entry         */37	int base;		/* Actual port address          */38	int base_hi;		/* Hi Base address for ECP-ISA chipset */39	int mode;		/* Transfer mode                */40	struct scsi_cmnd *cur_cmd;	/* Current queued command       */41	struct delayed_work imm_tq;	/* Polling interrupt stuff       */42	unsigned long jstart;	/* Jiffies at start             */43	unsigned failed:1;	/* Failure flag                 */44	unsigned dp:1;		/* Data phase present           */45	unsigned rd:1;		/* Read data in data phase      */46	unsigned wanted:1;	/* Parport sharing busy flag    */47	unsigned int dev_no;	/* Device number		*/48	wait_queue_head_t *waiting;49	struct Scsi_Host *host;50	struct list_head list;51} imm_struct;52 53static void imm_reset_pulse(unsigned int base);54static int device_check(imm_struct *dev, bool autodetect);55 56#include "imm.h"57 58static unsigned int mode = IMM_AUTODETECT;59module_param(mode, uint, 0644);60MODULE_PARM_DESC(mode, "Transfer mode (0 = Autodetect, 1 = SPP 4-bit, "61	"2 = SPP 8-bit, 3 = EPP 8-bit, 4 = EPP 16-bit, 5 = EPP 32-bit");62 63static inline imm_struct *imm_dev(struct Scsi_Host *host)64{65	return *(imm_struct **)&host->hostdata;66}67 68static DEFINE_SPINLOCK(arbitration_lock);69 70static void got_it(imm_struct *dev)71{72	dev->base = dev->dev->port->base;73	if (dev->cur_cmd)74		imm_scsi_pointer(dev->cur_cmd)->phase = 1;75	else76		wake_up(dev->waiting);77}78 79static void imm_wakeup(void *ref)80{81	imm_struct *dev = (imm_struct *) ref;82	unsigned long flags;83 84	spin_lock_irqsave(&arbitration_lock, flags);85	if (dev->wanted) {86		if (parport_claim(dev->dev) == 0) {87			got_it(dev);88			dev->wanted = 0;89		}90	}91	spin_unlock_irqrestore(&arbitration_lock, flags);92}93 94static int imm_pb_claim(imm_struct *dev)95{96	unsigned long flags;97	int res = 1;98	spin_lock_irqsave(&arbitration_lock, flags);99	if (parport_claim(dev->dev) == 0) {100		got_it(dev);101		res = 0;102	}103	dev->wanted = res;104	spin_unlock_irqrestore(&arbitration_lock, flags);105	return res;106}107 108static void imm_pb_dismiss(imm_struct *dev)109{110	unsigned long flags;111	int wanted;112	spin_lock_irqsave(&arbitration_lock, flags);113	wanted = dev->wanted;114	dev->wanted = 0;115	spin_unlock_irqrestore(&arbitration_lock, flags);116	if (!wanted)117		parport_release(dev->dev);118}119 120static inline void imm_pb_release(imm_struct *dev)121{122	parport_release(dev->dev);123}124 125/* This is to give the imm driver a way to modify the timings (and other126 * parameters) by writing to the /proc/scsi/imm/0 file.127 * Very simple method really... (Too simple, no error checking :( )128 * Reason: Kernel hackers HATE having to unload and reload modules for129 * testing...130 * Also gives a method to use a script to obtain optimum timings (TODO)131 */132static int imm_write_info(struct Scsi_Host *host, char *buffer, int length)133{134	imm_struct *dev = imm_dev(host);135 136	if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {137		dev->mode = simple_strtoul(buffer + 5, NULL, 0);138		return length;139	}140	printk("imm /proc: invalid variable\n");141	return -EINVAL;142}143 144static int imm_show_info(struct seq_file *m, struct Scsi_Host *host)145{146	imm_struct *dev = imm_dev(host);147 148	seq_printf(m, "Version : %s\n", IMM_VERSION);149	seq_printf(m, "Parport : %s\n", dev->dev->port->name);150	seq_printf(m, "Mode    : %s\n", IMM_MODE_STRING[dev->mode]);151	return 0;152}153 154#if IMM_DEBUG > 0155#define imm_fail(x,y) printk("imm: imm_fail(%i) from %s at line %d\n",\156	   y, __func__, __LINE__); imm_fail_func(x,y);157static inline void158imm_fail_func(imm_struct *dev, int error_code)159#else160static inline void161imm_fail(imm_struct *dev, int error_code)162#endif163{164	/* If we fail a device then we trash status / message bytes */165	if (dev->cur_cmd) {166		dev->cur_cmd->result = error_code << 16;167		dev->failed = 1;168	}169}170 171/*172 * Wait for the high bit to be set.173 * 174 * In principle, this could be tied to an interrupt, but the adapter175 * doesn't appear to be designed to support interrupts.  We spin on176 * the 0x80 ready bit. 177 */178static unsigned char imm_wait(imm_struct *dev)179{180	int k;181	unsigned short ppb = dev->base;182	unsigned char r;183 184	w_ctr(ppb, 0x0c);185 186	k = IMM_SPIN_TMO;187	do {188		r = r_str(ppb);189		k--;190		udelay(1);191	}192	while (!(r & 0x80) && (k));193 194	/*195	 * STR register (LPT base+1) to SCSI mapping:196	 *197	 * STR      imm     imm198	 * ===================================199	 * 0x80     S_REQ   S_REQ200	 * 0x40     !S_BSY  (????)201	 * 0x20     !S_CD   !S_CD202	 * 0x10     !S_IO   !S_IO203	 * 0x08     (????)  !S_BSY204	 *205	 * imm      imm     meaning206	 * ==================================207	 * 0xf0     0xb8    Bit mask208	 * 0xc0     0x88    ZIP wants more data209	 * 0xd0     0x98    ZIP wants to send more data210	 * 0xe0     0xa8    ZIP is expecting SCSI command data211	 * 0xf0     0xb8    end of transfer, ZIP is sending status212	 */213	w_ctr(ppb, 0x04);214	if (k)215		return (r & 0xb8);216 217	/* Counter expired - Time out occurred */218	imm_fail(dev, DID_TIME_OUT);219	printk("imm timeout in imm_wait\n");220	return 0;		/* command timed out */221}222 223static int imm_negotiate(imm_struct * tmp)224{225	/*226	 * The following is supposedly the IEEE 1284-1994 negotiate227	 * sequence. I have yet to obtain a copy of the above standard228	 * so this is a bit of a guess...229	 *230	 * A fair chunk of this is based on the Linux parport implementation231	 * of IEEE 1284.232	 *233	 * Return 0 if data available234	 *        1 if no data available235	 */236 237	unsigned short base = tmp->base;238	unsigned char a, mode;239 240	switch (tmp->mode) {241	case IMM_NIBBLE:242		mode = 0x00;243		break;244	case IMM_PS2:245		mode = 0x01;246		break;247	default:248		return 0;249	}250 251	w_ctr(base, 0x04);252	udelay(5);253	w_dtr(base, mode);254	udelay(100);255	w_ctr(base, 0x06);256	udelay(5);257	a = (r_str(base) & 0x20) ? 0 : 1;258	udelay(5);259	w_ctr(base, 0x07);260	udelay(5);261	w_ctr(base, 0x06);262 263	if (a) {264		printk265		    ("IMM: IEEE1284 negotiate indicates no data available.\n");266		imm_fail(tmp, DID_ERROR);267	}268	return a;269}270 271/* 272 * Clear EPP timeout bit. 273 */274static inline void epp_reset(unsigned short ppb)275{276	int i;277 278	i = r_str(ppb);279	w_str(ppb, i);280	w_str(ppb, i & 0xfe);281}282 283/* 284 * Wait for empty ECP fifo (if we are in ECP fifo mode only)285 */286static inline void ecp_sync(imm_struct *dev)287{288	int i, ppb_hi = dev->base_hi;289 290	if (ppb_hi == 0)291		return;292 293	if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {	/* mode 011 == ECP fifo mode */294		for (i = 0; i < 100; i++) {295			if (r_ecr(ppb_hi) & 0x01)296				return;297			udelay(5);298		}299		printk("imm: ECP sync failed as data still present in FIFO.\n");300	}301}302 303static int imm_byte_out(unsigned short base, const char *buffer, int len)304{305	int i;306 307	w_ctr(base, 0x4);	/* apparently a sane mode */308	for (i = len >> 1; i; i--) {309		w_dtr(base, *buffer++);310		w_ctr(base, 0x5);	/* Drop STROBE low */311		w_dtr(base, *buffer++);312		w_ctr(base, 0x0);	/* STROBE high + INIT low */313	}314	w_ctr(base, 0x4);	/* apparently a sane mode */315	return 1;		/* All went well - we hope! */316}317 318static int imm_nibble_in(unsigned short base, char *buffer, int len)319{320	unsigned char l;321	int i;322 323	/*324	 * The following is based on documented timing signals325	 */326	w_ctr(base, 0x4);327	for (i = len; i; i--) {328		w_ctr(base, 0x6);329		l = (r_str(base) & 0xf0) >> 4;330		w_ctr(base, 0x5);331		*buffer++ = (r_str(base) & 0xf0) | l;332		w_ctr(base, 0x4);333	}334	return 1;		/* All went well - we hope! */335}336 337static int imm_byte_in(unsigned short base, char *buffer, int len)338{339	int i;340 341	/*342	 * The following is based on documented timing signals343	 */344	w_ctr(base, 0x4);345	for (i = len; i; i--) {346		w_ctr(base, 0x26);347		*buffer++ = r_dtr(base);348		w_ctr(base, 0x25);349	}350	return 1;		/* All went well - we hope! */351}352 353static int imm_out(imm_struct *dev, char *buffer, int len)354{355	unsigned short ppb = dev->base;356	int r = imm_wait(dev);357 358	/*359	 * Make sure that:360	 * a) the SCSI bus is BUSY (device still listening)361	 * b) the device is listening362	 */363	if ((r & 0x18) != 0x08) {364		imm_fail(dev, DID_ERROR);365		printk("IMM: returned SCSI status %2x\n", r);366		return 0;367	}368	switch (dev->mode) {369	case IMM_EPP_32:370	case IMM_EPP_16:371	case IMM_EPP_8:372		epp_reset(ppb);373		w_ctr(ppb, 0x4);374		if (dev->mode == IMM_EPP_32 && !(((long) buffer | len) & 0x03))375			outsl(ppb + 4, buffer, len >> 2);376		else if (dev->mode == IMM_EPP_16 && !(((long) buffer | len) & 0x01))377			outsw(ppb + 4, buffer, len >> 1);378		else379			outsb(ppb + 4, buffer, len);380		w_ctr(ppb, 0xc);381		r = !(r_str(ppb) & 0x01);382		w_ctr(ppb, 0xc);383		ecp_sync(dev);384		break;385 386	case IMM_NIBBLE:387	case IMM_PS2:388		/* 8 bit output, with a loop */389		r = imm_byte_out(ppb, buffer, len);390		break;391 392	default:393		printk("IMM: bug in imm_out()\n");394		r = 0;395	}396	return r;397}398 399static int imm_in(imm_struct *dev, char *buffer, int len)400{401	unsigned short ppb = dev->base;402	int r = imm_wait(dev);403 404	/*405	 * Make sure that:406	 * a) the SCSI bus is BUSY (device still listening)407	 * b) the device is sending data408	 */409	if ((r & 0x18) != 0x18) {410		imm_fail(dev, DID_ERROR);411		return 0;412	}413	switch (dev->mode) {414	case IMM_NIBBLE:415		/* 4 bit input, with a loop */416		r = imm_nibble_in(ppb, buffer, len);417		w_ctr(ppb, 0xc);418		break;419 420	case IMM_PS2:421		/* 8 bit input, with a loop */422		r = imm_byte_in(ppb, buffer, len);423		w_ctr(ppb, 0xc);424		break;425 426	case IMM_EPP_32:427	case IMM_EPP_16:428	case IMM_EPP_8:429		epp_reset(ppb);430		w_ctr(ppb, 0x24);431		if (dev->mode == IMM_EPP_32 && !(((long) buffer | len) & 0x03))432			insw(ppb + 4, buffer, len >> 2);433		else if (dev->mode == IMM_EPP_16 && !(((long) buffer | len) & 0x01))434			insl(ppb + 4, buffer, len >> 1);435		else436			insb(ppb + 4, buffer, len);437		w_ctr(ppb, 0x2c);438		r = !(r_str(ppb) & 0x01);439		w_ctr(ppb, 0x2c);440		ecp_sync(dev);441		break;442 443	default:444		printk("IMM: bug in imm_ins()\n");445		r = 0;446		break;447	}448	return r;449}450 451static int imm_cpp(unsigned short ppb, unsigned char b)452{453	/*454	 * Comments on udelay values refer to the455	 * Command Packet Protocol (CPP) timing diagram.456	 */457 458	unsigned char s1, s2, s3;459	w_ctr(ppb, 0x0c);460	udelay(2);		/* 1 usec - infinite */461	w_dtr(ppb, 0xaa);462	udelay(10);		/* 7 usec - infinite */463	w_dtr(ppb, 0x55);464	udelay(10);		/* 7 usec - infinite */465	w_dtr(ppb, 0x00);466	udelay(10);		/* 7 usec - infinite */467	w_dtr(ppb, 0xff);468	udelay(10);		/* 7 usec - infinite */469	s1 = r_str(ppb) & 0xb8;470	w_dtr(ppb, 0x87);471	udelay(10);		/* 7 usec - infinite */472	s2 = r_str(ppb) & 0xb8;473	w_dtr(ppb, 0x78);474	udelay(10);		/* 7 usec - infinite */475	s3 = r_str(ppb) & 0x38;476	/*477	 * Values for b are:478	 * 0000 00aa    Assign address aa to current device479	 * 0010 00aa    Select device aa in EPP Winbond mode480	 * 0010 10aa    Select device aa in EPP mode481	 * 0011 xxxx    Deselect all devices482	 * 0110 00aa    Test device aa483	 * 1101 00aa    Select device aa in ECP mode484	 * 1110 00aa    Select device aa in Compatible mode485	 */486	w_dtr(ppb, b);487	udelay(2);		/* 1 usec - infinite */488	w_ctr(ppb, 0x0c);489	udelay(10);		/* 7 usec - infinite */490	w_ctr(ppb, 0x0d);491	udelay(2);		/* 1 usec - infinite */492	w_ctr(ppb, 0x0c);493	udelay(10);		/* 7 usec - infinite */494	w_dtr(ppb, 0xff);495	udelay(10);		/* 7 usec - infinite */496 497	/*498	 * The following table is electrical pin values.499	 * (BSY is inverted at the CTR register)500	 *501	 *       BSY  ACK  POut SEL  Fault502	 * S1    0    X    1    1    1503	 * S2    1    X    0    1    1504	 * S3    L    X    1    1    S505	 *506	 * L => Last device in chain507	 * S => Selected508	 *509	 * Observered values for S1,S2,S3 are:510	 * Disconnect => f8/58/78511	 * Connect    => f8/58/70512	 */513	if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x30))514		return 1;	/* Connected */515	if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x38))516		return 0;	/* Disconnected */517 518	return -1;		/* No device present */519}520 521static inline int imm_connect(imm_struct *dev, int flag)522{523	unsigned short ppb = dev->base;524 525	imm_cpp(ppb, 0xe0);	/* Select device 0 in compatible mode */526	imm_cpp(ppb, 0x30);	/* Disconnect all devices */527 528	if ((dev->mode == IMM_EPP_8) ||529	    (dev->mode == IMM_EPP_16) ||530	    (dev->mode == IMM_EPP_32))531		return imm_cpp(ppb, 0x28);	/* Select device 0 in EPP mode */532	return imm_cpp(ppb, 0xe0);	/* Select device 0 in compatible mode */533}534 535static void imm_disconnect(imm_struct *dev)536{537	imm_cpp(dev->base, 0x30);	/* Disconnect all devices */538}539 540static int imm_select(imm_struct *dev, int target)541{542	int k;543	unsigned short ppb = dev->base;544 545	/*546	 * Firstly we want to make sure there is nothing547	 * holding onto the SCSI bus.548	 */549	w_ctr(ppb, 0xc);550 551	k = IMM_SELECT_TMO;552	do {553		k--;554	} while ((r_str(ppb) & 0x08) && (k));555 556	if (!k)557		return 0;558 559	/*560	 * Now assert the SCSI ID (HOST and TARGET) on the data bus561	 */562	w_ctr(ppb, 0x4);563	w_dtr(ppb, 0x80 | (1 << target));564	udelay(1);565 566	/*567	 * Deassert SELIN first followed by STROBE568	 */569	w_ctr(ppb, 0xc);570	w_ctr(ppb, 0xd);571 572	/*573	 * ACK should drop low while SELIN is deasserted.574	 * FAULT should drop low when the SCSI device latches the bus.575	 */576	k = IMM_SELECT_TMO;577	do {578		k--;579	}580	while (!(r_str(ppb) & 0x08) && (k));581 582	/*583	 * Place the interface back into a sane state (status mode)584	 */585	w_ctr(ppb, 0xc);586	return (k) ? 1 : 0;587}588 589static int imm_init(imm_struct *dev)590{591	bool autodetect = dev->mode == IMM_AUTODETECT;592 593	if (autodetect) {594		int modes = dev->dev->port->modes;595 596		/* Mode detection works up the chain of speed597		 * This avoids a nasty if-then-else-if-... tree598		 */599		dev->mode = IMM_NIBBLE;600 601		if (modes & PARPORT_MODE_TRISTATE)602			dev->mode = IMM_PS2;603	}604 605	if (imm_connect(dev, 0) != 1)606		return -EIO;607	imm_reset_pulse(dev->base);608	mdelay(1);	/* Delay to allow devices to settle */609	imm_disconnect(dev);610	mdelay(1);	/* Another delay to allow devices to settle */611 612	return device_check(dev, autodetect);613}614 615static inline int imm_send_command(struct scsi_cmnd *cmd)616{617	imm_struct *dev = imm_dev(cmd->device->host);618	int k;619 620	/* NOTE: IMM uses byte pairs */621	for (k = 0; k < cmd->cmd_len; k += 2)622		if (!imm_out(dev, &cmd->cmnd[k], 2))623			return 0;624	return 1;625}626 627/*628 * The bulk flag enables some optimisations in the data transfer loops,629 * it should be true for any command that transfers data in integral630 * numbers of sectors.631 * 632 * The driver appears to remain stable if we speed up the parallel port633 * i/o in this function, but not elsewhere.634 */635static int imm_completion(struct scsi_cmnd *const cmd)636{637	/* Return codes:638	 * -1     Error639	 *  0     Told to schedule640	 *  1     Finished data transfer641	 */642	struct scsi_pointer *scsi_pointer = imm_scsi_pointer(cmd);643	imm_struct *dev = imm_dev(cmd->device->host);644	unsigned short ppb = dev->base;645	unsigned long start_jiffies = jiffies;646 647	unsigned char r, v;648	int fast, bulk, status;649 650	v = cmd->cmnd[0];651	bulk = ((v == READ_6) ||652		(v == READ_10) || (v == WRITE_6) || (v == WRITE_10));653 654	/*655	 * We only get here if the drive is ready to comunicate,656	 * hence no need for a full imm_wait.657	 */658	w_ctr(ppb, 0x0c);659	r = (r_str(ppb) & 0xb8);660 661	/*662	 * while (device is not ready to send status byte)663	 *     loop;664	 */665	while (r != (unsigned char) 0xb8) {666		/*667		 * If we have been running for more than a full timer tick668		 * then take a rest.669		 */670		if (time_after(jiffies, start_jiffies + 1))671			return 0;672 673		/*674		 * FAIL if:675		 * a) Drive status is screwy (!ready && !present)676		 * b) Drive is requesting/sending more data than expected677		 */678		if ((r & 0x88) != 0x88 || scsi_pointer->this_residual <= 0) {679			imm_fail(dev, DID_ERROR);680			return -1;	/* ERROR_RETURN */681		}682		/* determine if we should use burst I/O */683		if (dev->rd == 0) {684			fast = bulk && scsi_pointer->this_residual >=685				IMM_BURST_SIZE ? IMM_BURST_SIZE : 2;686			status = imm_out(dev, scsi_pointer->ptr, fast);687		} else {688			fast = bulk && scsi_pointer->this_residual >=689				IMM_BURST_SIZE ? IMM_BURST_SIZE : 1;690			status = imm_in(dev, scsi_pointer->ptr, fast);691		}692 693		scsi_pointer->ptr += fast;694		scsi_pointer->this_residual -= fast;695 696		if (!status) {697			imm_fail(dev, DID_BUS_BUSY);698			return -1;	/* ERROR_RETURN */699		}700		if (scsi_pointer->buffer && !scsi_pointer->this_residual) {701			/* if scatter/gather, advance to the next segment */702			if (scsi_pointer->buffers_residual--) {703				scsi_pointer->buffer =704					sg_next(scsi_pointer->buffer);705				scsi_pointer->this_residual =706				    scsi_pointer->buffer->length;707				scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);708 709				/*710				 * Make sure that we transfer even number of bytes711				 * otherwise it makes imm_byte_out() messy.712				 */713				if (scsi_pointer->this_residual & 0x01)714					scsi_pointer->this_residual++;715			}716		}717		/* Now check to see if the drive is ready to comunicate */718		w_ctr(ppb, 0x0c);719		r = (r_str(ppb) & 0xb8);720 721		/* If not, drop back down to the scheduler and wait a timer tick */722		if (!(r & 0x80))723			return 0;724	}725	return 1;		/* FINISH_RETURN */726}727 728/*729 * Since the IMM itself doesn't generate interrupts, we use730 * the scheduler's task queue to generate a stream of call-backs and731 * complete the request when the drive is ready.732 */733static void imm_interrupt(struct work_struct *work)734{735	imm_struct *dev = container_of(work, imm_struct, imm_tq.work);736	struct scsi_cmnd *cmd = dev->cur_cmd;737	struct Scsi_Host *host = cmd->device->host;738	unsigned long flags;739 740	if (imm_engine(dev, cmd)) {741		schedule_delayed_work(&dev->imm_tq, 1);742		return;743	}744	/* Command must of completed hence it is safe to let go... */745#if IMM_DEBUG > 0746	switch ((cmd->result >> 16) & 0xff) {747	case DID_OK:748		break;749	case DID_NO_CONNECT:750		printk("imm: no device at SCSI ID %i\n", cmd->device->id);751		break;752	case DID_BUS_BUSY:753		printk("imm: BUS BUSY - EPP timeout detected\n");754		break;755	case DID_TIME_OUT:756		printk("imm: unknown timeout\n");757		break;758	case DID_ABORT:759		printk("imm: told to abort\n");760		break;761	case DID_PARITY:762		printk("imm: parity error (???)\n");763		break;764	case DID_ERROR:765		printk("imm: internal driver error\n");766		break;767	case DID_RESET:768		printk("imm: told to reset device\n");769		break;770	case DID_BAD_INTR:771		printk("imm: bad interrupt (???)\n");772		break;773	default:774		printk("imm: bad return code (%02x)\n",775		       (cmd->result >> 16) & 0xff);776	}777#endif778 779	if (imm_scsi_pointer(cmd)->phase > 1)780		imm_disconnect(dev);781 782	imm_pb_dismiss(dev);783 784	spin_lock_irqsave(host->host_lock, flags);785	dev->cur_cmd = NULL;786	scsi_done(cmd);787	spin_unlock_irqrestore(host->host_lock, flags);788	return;789}790 791static int imm_engine(imm_struct *dev, struct scsi_cmnd *const cmd)792{793	struct scsi_pointer *scsi_pointer = imm_scsi_pointer(cmd);794	unsigned short ppb = dev->base;795	unsigned char l = 0, h = 0;796	int retv, x;797 798	/* First check for any errors that may have occurred799	 * Here we check for internal errors800	 */801	if (dev->failed)802		return 0;803 804	switch (scsi_pointer->phase) {805	case 0:		/* Phase 0 - Waiting for parport */806		if (time_after(jiffies, dev->jstart + HZ)) {807			/*808			 * We waited more than a second809			 * for parport to call us810			 */811			imm_fail(dev, DID_BUS_BUSY);812			return 0;813		}814		return 1;	/* wait until imm_wakeup claims parport */815 816	case 1:		/* Phase 1 - Connected */817		imm_connect(dev, CONNECT_EPP_MAYBE);818		scsi_pointer->phase++;819		fallthrough;820 821	case 2:		/* Phase 2 - We are now talking to the scsi bus */822		if (!imm_select(dev, scmd_id(cmd))) {823			imm_fail(dev, DID_NO_CONNECT);824			return 0;825		}826		scsi_pointer->phase++;827		fallthrough;828 829	case 3:		/* Phase 3 - Ready to accept a command */830		w_ctr(ppb, 0x0c);831		if (!(r_str(ppb) & 0x80))832			return 1;833 834		if (!imm_send_command(cmd))835			return 0;836		scsi_pointer->phase++;837		fallthrough;838 839	case 4:		/* Phase 4 - Setup scatter/gather buffers */840		if (scsi_bufflen(cmd)) {841			scsi_pointer->buffer = scsi_sglist(cmd);842			scsi_pointer->this_residual = scsi_pointer->buffer->length;843			scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);844		} else {845			scsi_pointer->buffer = NULL;846			scsi_pointer->this_residual = 0;847			scsi_pointer->ptr = NULL;848		}849		scsi_pointer->buffers_residual = scsi_sg_count(cmd) - 1;850		scsi_pointer->phase++;851		if (scsi_pointer->this_residual & 0x01)852			scsi_pointer->this_residual++;853		fallthrough;854 855	case 5:		/* Phase 5 - Pre-Data transfer stage */856		/* Spin lock for BUSY */857		w_ctr(ppb, 0x0c);858		if (!(r_str(ppb) & 0x80))859			return 1;860 861		/* Require negotiation for read requests */862		x = (r_str(ppb) & 0xb8);863		dev->rd = (x & 0x10) ? 1 : 0;864		dev->dp = (x & 0x20) ? 0 : 1;865 866		if ((dev->dp) && (dev->rd))867			if (imm_negotiate(dev))868				return 0;869		scsi_pointer->phase++;870		fallthrough;871 872	case 6:		/* Phase 6 - Data transfer stage */873		/* Spin lock for BUSY */874		w_ctr(ppb, 0x0c);875		if (!(r_str(ppb) & 0x80))876			return 1;877 878		if (dev->dp) {879			retv = imm_completion(cmd);880			if (retv == -1)881				return 0;882			if (retv == 0)883				return 1;884		}885		scsi_pointer->phase++;886		fallthrough;887 888	case 7:		/* Phase 7 - Post data transfer stage */889		if ((dev->dp) && (dev->rd)) {890			if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {891				w_ctr(ppb, 0x4);892				w_ctr(ppb, 0xc);893				w_ctr(ppb, 0xe);894				w_ctr(ppb, 0x4);895			}896		}897		scsi_pointer->phase++;898		fallthrough;899 900	case 8:		/* Phase 8 - Read status/message */901		/* Check for data overrun */902		if (imm_wait(dev) != (unsigned char) 0xb8) {903			imm_fail(dev, DID_ERROR);904			return 0;905		}906		if (imm_negotiate(dev))907			return 0;908		if (imm_in(dev, &l, 1)) {	/* read status byte */909			/* Check for optional message byte */910			if (imm_wait(dev) == (unsigned char) 0xb8)911				imm_in(dev, &h, 1);912			cmd->result = (DID_OK << 16) | (l & STATUS_MASK);913		}914		if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {915			w_ctr(ppb, 0x4);916			w_ctr(ppb, 0xc);917			w_ctr(ppb, 0xe);918			w_ctr(ppb, 0x4);919		}920		return 0;	/* Finished */921 922	default:923		printk("imm: Invalid scsi phase\n");924	}925	return 0;926}927 928static int imm_queuecommand_lck(struct scsi_cmnd *cmd)929{930	imm_struct *dev = imm_dev(cmd->device->host);931 932	if (dev->cur_cmd) {933		printk("IMM: bug in imm_queuecommand\n");934		return 0;935	}936	dev->failed = 0;937	dev->jstart = jiffies;938	dev->cur_cmd = cmd;939	cmd->result = DID_ERROR << 16;	/* default return code */940	imm_scsi_pointer(cmd)->phase = 0;	/* bus free */941 942	schedule_delayed_work(&dev->imm_tq, 0);943 944	imm_pb_claim(dev);945 946	return 0;947}948 949static DEF_SCSI_QCMD(imm_queuecommand)950 951/*952 * Apparently the disk->capacity attribute is off by 1 sector 953 * for all disk drives.  We add the one here, but it should really954 * be done in sd.c.  Even if it gets fixed there, this will still955 * work.956 */957static int imm_biosparam(struct scsi_device *sdev, struct block_device *dev,958			 sector_t capacity, int ip[])959{960	ip[0] = 0x40;961	ip[1] = 0x20;962	ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);963	if (ip[2] > 1024) {964		ip[0] = 0xff;965		ip[1] = 0x3f;966		ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);967	}968	return 0;969}970 971static int imm_abort(struct scsi_cmnd *cmd)972{973	imm_struct *dev = imm_dev(cmd->device->host);974	/*975	 * There is no method for aborting commands since Iomega976	 * have tied the SCSI_MESSAGE line high in the interface977	 */978 979	switch (imm_scsi_pointer(cmd)->phase) {980	case 0:		/* Do not have access to parport */981	case 1:		/* Have not connected to interface */982		dev->cur_cmd = NULL;	/* Forget the problem */983		return SUCCESS;984	default:		/* SCSI command sent, can not abort */985		return FAILED;986	}987}988 989static void imm_reset_pulse(unsigned int base)990{991	w_ctr(base, 0x04);992	w_dtr(base, 0x40);993	udelay(1);994	w_ctr(base, 0x0c);995	w_ctr(base, 0x0d);996	udelay(50);997	w_ctr(base, 0x0c);998	w_ctr(base, 0x04);999}1000 1001static int imm_reset(struct scsi_cmnd *cmd)1002{1003	imm_struct *dev = imm_dev(cmd->device->host);1004 1005	if (imm_scsi_pointer(cmd)->phase)1006		imm_disconnect(dev);1007	dev->cur_cmd = NULL;	/* Forget the problem */1008 1009	imm_connect(dev, CONNECT_NORMAL);1010	imm_reset_pulse(dev->base);1011	mdelay(1);		/* device settle delay */1012	imm_disconnect(dev);1013	mdelay(1);		/* device settle delay */1014	return SUCCESS;1015}1016 1017static int device_check(imm_struct *dev, bool autodetect)1018{1019	/* This routine looks for a device and then attempts to use EPP1020	   to send a command. If all goes as planned then EPP is available. */1021 1022	static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };1023	int loop, old_mode, status, k, ppb = dev->base;1024	unsigned char l;1025 1026	old_mode = dev->mode;1027	for (loop = 0; loop < 8; loop++) {1028		/* Attempt to use EPP for Test Unit Ready */1029		if (autodetect && (ppb & 0x0007) == 0x0000)1030			dev->mode = IMM_EPP_8;1031 1032	      second_pass:1033		imm_connect(dev, CONNECT_EPP_MAYBE);1034		/* Select SCSI device */1035		if (!imm_select(dev, loop)) {1036			imm_disconnect(dev);1037			continue;1038		}1039		printk("imm: Found device at ID %i, Attempting to use %s\n",1040		       loop, IMM_MODE_STRING[dev->mode]);1041 1042		/* Send SCSI command */1043		status = 1;1044		w_ctr(ppb, 0x0c);1045		for (l = 0; (l < 3) && (status); l++)1046			status = imm_out(dev, &cmd[l << 1], 2);1047 1048		if (!status) {1049			imm_disconnect(dev);1050			imm_connect(dev, CONNECT_EPP_MAYBE);1051			imm_reset_pulse(dev->base);1052			udelay(1000);1053			imm_disconnect(dev);1054			udelay(1000);1055			if (dev->mode != old_mode) {1056				dev->mode = old_mode;1057				goto second_pass;1058			}1059			printk("imm: Unable to establish communication\n");1060			return -EIO;1061		}1062		w_ctr(ppb, 0x0c);1063 1064		k = 1000000;	/* 1 Second */1065		do {1066			l = r_str(ppb);1067			k--;1068			udelay(1);1069		} while (!(l & 0x80) && (k));1070 1071		l &= 0xb8;1072 1073		if (l != 0xb8) {1074			imm_disconnect(dev);1075			imm_connect(dev, CONNECT_EPP_MAYBE);1076			imm_reset_pulse(dev->base);1077			udelay(1000);1078			imm_disconnect(dev);1079			udelay(1000);1080			if (dev->mode != old_mode) {1081				dev->mode = old_mode;1082				goto second_pass;1083			}1084			printk1085			    ("imm: Unable to establish communication\n");1086			return -EIO;1087		}1088		imm_disconnect(dev);1089		printk1090		    ("imm: Communication established at 0x%x with ID %i using %s\n",1091		     ppb, loop, IMM_MODE_STRING[dev->mode]);1092		imm_connect(dev, CONNECT_EPP_MAYBE);1093		imm_reset_pulse(dev->base);1094		udelay(1000);1095		imm_disconnect(dev);1096		udelay(1000);1097		return 0;1098	}1099	printk("imm: No devices found\n");1100	return -ENODEV;1101}1102 1103static const struct scsi_host_template imm_template = {1104	.module			= THIS_MODULE,1105	.proc_name		= "imm",1106	.show_info		= imm_show_info,1107	.write_info		= imm_write_info,1108	.name			= "Iomega VPI2 (imm) interface",1109	.queuecommand		= imm_queuecommand,1110	.eh_abort_handler	= imm_abort,1111	.eh_host_reset_handler	= imm_reset,1112	.bios_param		= imm_biosparam,1113	.this_id		= 7,1114	.sg_tablesize		= SG_ALL,1115	.can_queue		= 1,1116	.cmd_size		= sizeof(struct scsi_pointer),1117};1118 1119/***************************************************************************1120 *                   Parallel port probing routines                        *1121 ***************************************************************************/1122 1123static LIST_HEAD(imm_hosts);1124 1125/*1126 * Finds the first available device number that can be alloted to the1127 * new imm device and returns the address of the previous node so that1128 * we can add to the tail and have a list in the ascending order.1129 */1130 1131static inline imm_struct *find_parent(void)1132{1133	imm_struct *dev, *par = NULL;1134	unsigned int cnt = 0;1135 1136	if (list_empty(&imm_hosts))1137		return NULL;1138 1139	list_for_each_entry(dev, &imm_hosts, list) {1140		if (dev->dev_no != cnt)1141			return par;1142		cnt++;1143		par = dev;1144	}1145 1146	return par;1147}1148 1149static int __imm_attach(struct parport *pb)1150{1151	struct Scsi_Host *host;1152	imm_struct *dev, *temp;1153	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);1154	DEFINE_WAIT(wait);1155	int ports;1156	int err = -ENOMEM;1157	struct pardev_cb imm_cb;1158 1159	init_waitqueue_head(&waiting);1160 1161	dev = kzalloc(sizeof(imm_struct), GFP_KERNEL);1162	if (!dev)1163		return -ENOMEM;1164 1165 1166	dev->base = -1;1167	dev->mode = mode < IMM_UNKNOWN ? mode : IMM_AUTODETECT;1168	INIT_LIST_HEAD(&dev->list);1169 1170	temp = find_parent();1171	if (temp)1172		dev->dev_no = temp->dev_no + 1;1173 1174	memset(&imm_cb, 0, sizeof(imm_cb));1175	imm_cb.private = dev;1176	imm_cb.wakeup = imm_wakeup;1177 1178	dev->dev = parport_register_dev_model(pb, "imm", &imm_cb, dev->dev_no);1179	if (!dev->dev)1180		goto out;1181 1182 1183	/* Claim the bus so it remembers what we do to the control1184	 * registers. [ CTR and ECP ]1185	 */1186	err = -EBUSY;1187	dev->waiting = &waiting;1188	prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);1189	if (imm_pb_claim(dev))1190		schedule_timeout(3 * HZ);1191	if (dev->wanted) {1192		printk(KERN_ERR "imm%d: failed to claim parport because "1193			"a pardevice is owning the port for too long "1194			"time!\n", pb->number);1195		imm_pb_dismiss(dev);1196		dev->waiting = NULL;1197		finish_wait(&waiting, &wait);1198		goto out1;1199	}1200	dev->waiting = NULL;1201	finish_wait(&waiting, &wait);1202	dev->base = dev->dev->port->base;1203	dev->base_hi = dev->dev->port->base_hi;1204	w_ctr(dev->base, 0x0c);1205 1206	/* Done configuration */1207 1208	err = imm_init(dev);1209 1210	imm_pb_release(dev);1211 1212	if (err)1213		goto out1;1214 1215	/* now the glue ... */1216	if (dev->mode == IMM_NIBBLE || dev->mode == IMM_PS2)1217		ports = 3;1218	else1219		ports = 8;1220 1221	INIT_DELAYED_WORK(&dev->imm_tq, imm_interrupt);1222 1223	err = -ENOMEM;1224	host = scsi_host_alloc(&imm_template, sizeof(imm_struct *));1225	if (!host)1226		goto out1;1227	host->no_highmem = true;1228	host->io_port = pb->base;1229	host->n_io_port = ports;1230	host->dma_channel = -1;1231	host->unique_id = pb->number;1232	*(imm_struct **)&host->hostdata = dev;1233	dev->host = host;1234	if (!temp)1235		list_add_tail(&dev->list, &imm_hosts);1236	else1237		list_add_tail(&dev->list, &temp->list);1238	err = scsi_add_host(host, NULL);1239	if (err)1240		goto out2;1241	scsi_scan_host(host);1242	return 0;1243 1244out2:1245	list_del_init(&dev->list);1246	scsi_host_put(host);1247out1:1248	parport_unregister_device(dev->dev);1249out:1250	kfree(dev);1251	return err;1252}1253 1254static void imm_attach(struct parport *pb)1255{1256	__imm_attach(pb);1257}1258 1259static void imm_detach(struct parport *pb)1260{1261	imm_struct *dev;1262	list_for_each_entry(dev, &imm_hosts, list) {1263		if (dev->dev->port == pb) {1264			list_del_init(&dev->list);1265			scsi_remove_host(dev->host);1266			scsi_host_put(dev->host);1267			parport_unregister_device(dev->dev);1268			kfree(dev);1269			break;1270		}1271	}1272}1273 1274static struct parport_driver imm_driver = {1275	.name		= "imm",1276	.match_port	= imm_attach,1277	.detach		= imm_detach,1278};1279module_parport_driver(imm_driver);1280 1281MODULE_DESCRIPTION("IOMEGA MatchMaker parallel port SCSI host adapter driver");1282MODULE_LICENSE("GPL");1283