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/drivers/scsi/mac_esp.c

http://github.com/mirrors/linux
C | 460 lines | 363 code | 74 blank | 23 comment | 37 complexity | ff7ba05af8a687abd65a3529da00ac18 MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-only
  2/* mac_esp.c: ESP front-end for Macintosh Quadra systems.
  3 *
  4 * Adapted from jazz_esp.c and the old mac_esp.c.
  5 *
  6 * The pseudo DMA algorithm is based on the one used in NetBSD.
  7 * See sys/arch/mac68k/obio/esp.c for some background information.
  8 *
  9 * Copyright (C) 2007-2008 Finn Thain
 10 */
 11
 12#include <linux/kernel.h>
 13#include <linux/types.h>
 14#include <linux/module.h>
 15#include <linux/init.h>
 16#include <linux/interrupt.h>
 17#include <linux/platform_device.h>
 18#include <linux/dma-mapping.h>
 19#include <linux/scatterlist.h>
 20#include <linux/delay.h>
 21#include <linux/io.h>
 22#include <linux/nubus.h>
 23#include <linux/slab.h>
 24
 25#include <asm/irq.h>
 26#include <asm/dma.h>
 27#include <asm/macints.h>
 28#include <asm/macintosh.h>
 29#include <asm/mac_via.h>
 30
 31#include <scsi/scsi_host.h>
 32
 33#include "esp_scsi.h"
 34
 35#define DRV_MODULE_NAME     "mac_esp"
 36#define PFX                 DRV_MODULE_NAME ": "
 37#define DRV_VERSION         "1.000"
 38#define DRV_MODULE_RELDATE  "Sept 15, 2007"
 39
 40#define MAC_ESP_IO_BASE          0x50F00000
 41#define MAC_ESP_REGS_QUADRA      (MAC_ESP_IO_BASE + 0x10000)
 42#define MAC_ESP_REGS_QUADRA2     (MAC_ESP_IO_BASE + 0xF000)
 43#define MAC_ESP_REGS_QUADRA3     (MAC_ESP_IO_BASE + 0x18000)
 44#define MAC_ESP_REGS_SPACING     0x402
 45#define MAC_ESP_PDMA_REG         0xF9800024
 46#define MAC_ESP_PDMA_REG_SPACING 0x4
 47#define MAC_ESP_PDMA_IO_OFFSET   0x100
 48
 49#define esp_read8(REG)		mac_esp_read8(esp, REG)
 50#define esp_write8(VAL, REG)	mac_esp_write8(esp, VAL, REG)
 51
 52struct mac_esp_priv {
 53	struct esp *esp;
 54	void __iomem *pdma_regs;
 55	void __iomem *pdma_io;
 56};
 57static struct esp *esp_chips[2];
 58static DEFINE_SPINLOCK(esp_chips_lock);
 59
 60#define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
 61			       dev_get_drvdata((esp)->dev))
 62
 63static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
 64{
 65	nubus_writeb(val, esp->regs + reg * 16);
 66}
 67
 68static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
 69{
 70	return nubus_readb(esp->regs + reg * 16);
 71}
 72
 73static void mac_esp_reset_dma(struct esp *esp)
 74{
 75	/* Nothing to do. */
 76}
 77
 78static void mac_esp_dma_drain(struct esp *esp)
 79{
 80	/* Nothing to do. */
 81}
 82
 83static void mac_esp_dma_invalidate(struct esp *esp)
 84{
 85	/* Nothing to do. */
 86}
 87
 88static int mac_esp_dma_error(struct esp *esp)
 89{
 90	return esp->send_cmd_error;
 91}
 92
 93static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
 94{
 95	int i = 500000;
 96
 97	do {
 98		if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
 99			return 0;
100
101		if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
102			return 1;
103
104		udelay(2);
105	} while (--i);
106
107	printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
108	       esp_read8(ESP_STATUS));
109	esp->send_cmd_error = 1;
110	return 1;
111}
112
113static inline int mac_esp_wait_for_dreq(struct esp *esp)
114{
115	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
116	int i = 500000;
117
118	do {
119		if (mep->pdma_regs == NULL) {
120			if (via2_scsi_drq_pending())
121				return 0;
122		} else {
123			if (nubus_readl(mep->pdma_regs) & 0x200)
124				return 0;
125		}
126
127		if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
128			return 1;
129
130		udelay(2);
131	} while (--i);
132
133	printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
134	       esp_read8(ESP_STATUS));
135	esp->send_cmd_error = 1;
136	return 1;
137}
138
139#define MAC_ESP_PDMA_LOOP(operands) \
140	asm volatile ( \
141	     "       tstw %1                   \n" \
142	     "       jbeq 20f                  \n" \
143	     "1:     movew " operands "        \n" \
144	     "2:     movew " operands "        \n" \
145	     "3:     movew " operands "        \n" \
146	     "4:     movew " operands "        \n" \
147	     "5:     movew " operands "        \n" \
148	     "6:     movew " operands "        \n" \
149	     "7:     movew " operands "        \n" \
150	     "8:     movew " operands "        \n" \
151	     "9:     movew " operands "        \n" \
152	     "10:    movew " operands "        \n" \
153	     "11:    movew " operands "        \n" \
154	     "12:    movew " operands "        \n" \
155	     "13:    movew " operands "        \n" \
156	     "14:    movew " operands "        \n" \
157	     "15:    movew " operands "        \n" \
158	     "16:    movew " operands "        \n" \
159	     "       subqw #1,%1               \n" \
160	     "       jbne 1b                   \n" \
161	     "20:    tstw %2                   \n" \
162	     "       jbeq 30f                  \n" \
163	     "21:    movew " operands "        \n" \
164	     "       subqw #1,%2               \n" \
165	     "       jbne 21b                  \n" \
166	     "30:    tstw %3                   \n" \
167	     "       jbeq 40f                  \n" \
168	     "31:    moveb " operands "        \n" \
169	     "32:    nop                       \n" \
170	     "40:                              \n" \
171	     "                                 \n" \
172	     "       .section __ex_table,\"a\" \n" \
173	     "       .align  4                 \n" \
174	     "       .long   1b,40b            \n" \
175	     "       .long   2b,40b            \n" \
176	     "       .long   3b,40b            \n" \
177	     "       .long   4b,40b            \n" \
178	     "       .long   5b,40b            \n" \
179	     "       .long   6b,40b            \n" \
180	     "       .long   7b,40b            \n" \
181	     "       .long   8b,40b            \n" \
182	     "       .long   9b,40b            \n" \
183	     "       .long  10b,40b            \n" \
184	     "       .long  11b,40b            \n" \
185	     "       .long  12b,40b            \n" \
186	     "       .long  13b,40b            \n" \
187	     "       .long  14b,40b            \n" \
188	     "       .long  15b,40b            \n" \
189	     "       .long  16b,40b            \n" \
190	     "       .long  21b,40b            \n" \
191	     "       .long  31b,40b            \n" \
192	     "       .long  32b,40b            \n" \
193	     "       .previous                 \n" \
194	     : "+a" (addr), "+r" (count32), "+r" (count2) \
195	     : "g" (count1), "a" (mep->pdma_io))
196
197static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
198				  u32 dma_count, int write, u8 cmd)
199{
200	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
201
202	esp->send_cmd_error = 0;
203
204	if (!write)
205		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
206
207	esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
208	esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
209
210	scsi_esp_cmd(esp, cmd);
211
212	do {
213		unsigned int count32 = esp_count >> 5;
214		unsigned int count2 = (esp_count & 0x1F) >> 1;
215		unsigned int count1 = esp_count & 1;
216		unsigned int start_addr = addr;
217
218		if (mac_esp_wait_for_dreq(esp))
219			break;
220
221		if (write) {
222			MAC_ESP_PDMA_LOOP("%4@,%0@+");
223
224			esp_count -= addr - start_addr;
225		} else {
226			unsigned int n;
227
228			MAC_ESP_PDMA_LOOP("%0@+,%4@");
229
230			if (mac_esp_wait_for_empty_fifo(esp))
231				break;
232
233			n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
234			addr = start_addr + esp_count - n;
235			esp_count = n;
236		}
237	} while (esp_count);
238}
239
240static int mac_esp_irq_pending(struct esp *esp)
241{
242	if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
243		return 1;
244	return 0;
245}
246
247static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
248{
249	return dma_len > 0xFFFF ? 0xFFFF : dma_len;
250}
251
252static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
253{
254	int got_intr;
255
256	/*
257	 * This is an edge triggered IRQ, so we have to be careful to
258	 * avoid missing a transition when it is shared by two ESP devices.
259	 */
260
261	do {
262		got_intr = 0;
263		if (esp_chips[0] &&
264		    (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
265			(void)scsi_esp_intr(irq, esp_chips[0]);
266			got_intr = 1;
267		}
268		if (esp_chips[1] &&
269		    (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
270			(void)scsi_esp_intr(irq, esp_chips[1]);
271			got_intr = 1;
272		}
273	} while (got_intr);
274
275	return IRQ_HANDLED;
276}
277
278static struct esp_driver_ops mac_esp_ops = {
279	.esp_write8       = mac_esp_write8,
280	.esp_read8        = mac_esp_read8,
281	.irq_pending      = mac_esp_irq_pending,
282	.dma_length_limit = mac_esp_dma_length_limit,
283	.reset_dma        = mac_esp_reset_dma,
284	.dma_drain        = mac_esp_dma_drain,
285	.dma_invalidate   = mac_esp_dma_invalidate,
286	.send_dma_cmd     = mac_esp_send_pdma_cmd,
287	.dma_error        = mac_esp_dma_error,
288};
289
290static int esp_mac_probe(struct platform_device *dev)
291{
292	struct scsi_host_template *tpnt = &scsi_esp_template;
293	struct Scsi_Host *host;
294	struct esp *esp;
295	int err;
296	struct mac_esp_priv *mep;
297
298	if (!MACH_IS_MAC)
299		return -ENODEV;
300
301	if (dev->id > 1)
302		return -ENODEV;
303
304	host = scsi_host_alloc(tpnt, sizeof(struct esp));
305
306	err = -ENOMEM;
307	if (!host)
308		goto fail;
309
310	host->max_id = 8;
311	host->dma_boundary = PAGE_SIZE - 1;
312	esp = shost_priv(host);
313
314	esp->host = host;
315	esp->dev = &dev->dev;
316
317	esp->command_block = kzalloc(16, GFP_KERNEL);
318	if (!esp->command_block)
319		goto fail_unlink;
320	esp->command_block_dma = (dma_addr_t)esp->command_block;
321
322	esp->scsi_id = 7;
323	host->this_id = esp->scsi_id;
324	esp->scsi_id_mask = 1 << esp->scsi_id;
325
326	mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
327	if (!mep)
328		goto fail_free_command_block;
329	mep->esp = esp;
330	platform_set_drvdata(dev, mep);
331
332	switch (macintosh_config->scsi_type) {
333	case MAC_SCSI_QUADRA:
334		esp->cfreq     = 16500000;
335		esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA;
336		mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
337		mep->pdma_regs = NULL;
338		break;
339	case MAC_SCSI_QUADRA2:
340		esp->cfreq     = 25000000;
341		esp->regs      = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
342				 dev->id * MAC_ESP_REGS_SPACING);
343		mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
344		mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
345				 dev->id * MAC_ESP_PDMA_REG_SPACING);
346		nubus_writel(0x1d1, mep->pdma_regs);
347		break;
348	case MAC_SCSI_QUADRA3:
349		/* These quadras have a real DMA controller (the PSC) but we
350		 * don't know how to drive it so we must use PIO instead.
351		 */
352		esp->cfreq     = 25000000;
353		esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA3;
354		mep->pdma_io   = NULL;
355		mep->pdma_regs = NULL;
356		break;
357	}
358	esp->fifo_reg = esp->regs + ESP_FDATA * 16;
359
360	esp->ops = &mac_esp_ops;
361	esp->flags = ESP_FLAG_NO_DMA_MAP;
362	if (mep->pdma_io == NULL) {
363		printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
364		esp_write8(0, ESP_TCLOW);
365		esp_write8(0, ESP_TCMED);
366		esp->flags |= ESP_FLAG_DISABLE_SYNC;
367		mac_esp_ops.send_dma_cmd = esp_send_pio_cmd;
368	} else {
369		printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
370	}
371
372	host->irq = IRQ_MAC_SCSI;
373
374	/* The request_irq() call is intended to succeed for the first device
375	 * and fail for the second device.
376	 */
377	err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL);
378	spin_lock(&esp_chips_lock);
379	if (err < 0 && esp_chips[!dev->id] == NULL) {
380		spin_unlock(&esp_chips_lock);
381		goto fail_free_priv;
382	}
383	esp_chips[dev->id] = esp;
384	spin_unlock(&esp_chips_lock);
385
386	err = scsi_esp_register(esp);
387	if (err)
388		goto fail_free_irq;
389
390	return 0;
391
392fail_free_irq:
393	spin_lock(&esp_chips_lock);
394	esp_chips[dev->id] = NULL;
395	if (esp_chips[!dev->id] == NULL) {
396		spin_unlock(&esp_chips_lock);
397		free_irq(host->irq, NULL);
398	} else
399		spin_unlock(&esp_chips_lock);
400fail_free_priv:
401	kfree(mep);
402fail_free_command_block:
403	kfree(esp->command_block);
404fail_unlink:
405	scsi_host_put(host);
406fail:
407	return err;
408}
409
410static int esp_mac_remove(struct platform_device *dev)
411{
412	struct mac_esp_priv *mep = platform_get_drvdata(dev);
413	struct esp *esp = mep->esp;
414	unsigned int irq = esp->host->irq;
415
416	scsi_esp_unregister(esp);
417
418	spin_lock(&esp_chips_lock);
419	esp_chips[dev->id] = NULL;
420	if (esp_chips[!dev->id] == NULL) {
421		spin_unlock(&esp_chips_lock);
422		free_irq(irq, NULL);
423	} else
424		spin_unlock(&esp_chips_lock);
425
426	kfree(mep);
427
428	kfree(esp->command_block);
429
430	scsi_host_put(esp->host);
431
432	return 0;
433}
434
435static struct platform_driver esp_mac_driver = {
436	.probe    = esp_mac_probe,
437	.remove   = esp_mac_remove,
438	.driver   = {
439		.name	= DRV_MODULE_NAME,
440	},
441};
442
443static int __init mac_esp_init(void)
444{
445	return platform_driver_register(&esp_mac_driver);
446}
447
448static void __exit mac_esp_exit(void)
449{
450	platform_driver_unregister(&esp_mac_driver);
451}
452
453MODULE_DESCRIPTION("Mac ESP SCSI driver");
454MODULE_AUTHOR("Finn Thain");
455MODULE_LICENSE("GPL v2");
456MODULE_VERSION(DRV_VERSION);
457MODULE_ALIAS("platform:" DRV_MODULE_NAME);
458
459module_init(mac_esp_init);
460module_exit(mac_esp_exit);