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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 const 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_obj(struct mac_esp_priv);
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 void 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
433static struct platform_driver esp_mac_driver = {
434 .probe = esp_mac_probe,
435 .remove = esp_mac_remove,
436 .driver = {
437 .name = DRV_MODULE_NAME,
438 },
439};
440module_platform_driver(esp_mac_driver);
441
442MODULE_DESCRIPTION("Mac ESP SCSI driver");
443MODULE_AUTHOR("Finn Thain");
444MODULE_LICENSE("GPL v2");
445MODULE_VERSION(DRV_VERSION);
446MODULE_ALIAS("platform:" DRV_MODULE_NAME);