GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / scsi / mac_esp.c
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
52 struct mac_esp_priv {
53         struct esp *esp;
54         void __iomem *pdma_regs;
55         void __iomem *pdma_io;
56 };
57 static struct esp *esp_chips[2];
58 static DEFINE_SPINLOCK(esp_chips_lock);
59
60 #define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
61                                dev_get_drvdata((esp)->dev))
62
63 static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
64 {
65         nubus_writeb(val, esp->regs + reg * 16);
66 }
67
68 static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
69 {
70         return nubus_readb(esp->regs + reg * 16);
71 }
72
73 static void mac_esp_reset_dma(struct esp *esp)
74 {
75         /* Nothing to do. */
76 }
77
78 static void mac_esp_dma_drain(struct esp *esp)
79 {
80         /* Nothing to do. */
81 }
82
83 static void mac_esp_dma_invalidate(struct esp *esp)
84 {
85         /* Nothing to do. */
86 }
87
88 static int mac_esp_dma_error(struct esp *esp)
89 {
90         return esp->send_cmd_error;
91 }
92
93 static 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
113 static 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
197 static 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
240 static 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
247 static 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
252 static 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
278 static 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
290 static 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
392 fail_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);
400 fail_free_priv:
401         kfree(mep);
402 fail_free_command_block:
403         kfree(esp->command_block);
404 fail_unlink:
405         scsi_host_put(host);
406 fail:
407         return err;
408 }
409
410 static 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
435 static 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 module_platform_driver(esp_mac_driver);
443
444 MODULE_DESCRIPTION("Mac ESP SCSI driver");
445 MODULE_AUTHOR("Finn Thain");
446 MODULE_LICENSE("GPL v2");
447 MODULE_VERSION(DRV_VERSION);
448 MODULE_ALIAS("platform:" DRV_MODULE_NAME);