1 // SPDX-License-Identifier: GPL-2.0-only
2 /* mac_esp.c: ESP front-end for Macintosh Quadra systems.
4 * Adapted from jazz_esp.c and the old mac_esp.c.
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.
9 * Copyright (C) 2007-2008 Finn Thain
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>
22 #include <linux/nubus.h>
23 #include <linux/slab.h>
27 #include <asm/macints.h>
28 #include <asm/macintosh.h>
29 #include <asm/mac_via.h>
31 #include <scsi/scsi_host.h>
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"
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
49 #define esp_read8(REG) mac_esp_read8(esp, REG)
50 #define esp_write8(VAL, REG) mac_esp_write8(esp, VAL, REG)
54 void __iomem *pdma_regs;
55 void __iomem *pdma_io;
57 static struct esp *esp_chips[2];
58 static DEFINE_SPINLOCK(esp_chips_lock);
60 #define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
61 dev_get_drvdata((esp)->dev))
63 static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
65 nubus_writeb(val, esp->regs + reg * 16);
68 static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
70 return nubus_readb(esp->regs + reg * 16);
73 static void mac_esp_reset_dma(struct esp *esp)
78 static void mac_esp_dma_drain(struct esp *esp)
83 static void mac_esp_dma_invalidate(struct esp *esp)
88 static int mac_esp_dma_error(struct esp *esp)
90 return esp->send_cmd_error;
93 static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
98 if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
101 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
107 printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
108 esp_read8(ESP_STATUS));
109 esp->send_cmd_error = 1;
113 static inline int mac_esp_wait_for_dreq(struct esp *esp)
115 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
119 if (mep->pdma_regs == NULL) {
120 if (via2_scsi_drq_pending())
123 if (nubus_readl(mep->pdma_regs) & 0x200)
127 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
133 printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
134 esp_read8(ESP_STATUS));
135 esp->send_cmd_error = 1;
139 #define MAC_ESP_PDMA_LOOP(operands) \
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" \
163 "21: movew " operands " \n" \
168 "31: moveb " operands " \n" \
172 " .section __ex_table,\"a\" \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" \
194 : "+a" (addr), "+r" (count32), "+r" (count2) \
195 : "g" (count1), "a" (mep->pdma_io))
197 static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
198 u32 dma_count, int write, u8 cmd)
200 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
202 esp->send_cmd_error = 0;
205 scsi_esp_cmd(esp, ESP_CMD_FLUSH);
207 esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
208 esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
210 scsi_esp_cmd(esp, cmd);
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;
218 if (mac_esp_wait_for_dreq(esp))
222 MAC_ESP_PDMA_LOOP("%4@,%0@+");
224 esp_count -= addr - start_addr;
228 MAC_ESP_PDMA_LOOP("%0@+,%4@");
230 if (mac_esp_wait_for_empty_fifo(esp))
233 n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
234 addr = start_addr + esp_count - n;
240 static int mac_esp_irq_pending(struct esp *esp)
242 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
247 static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
249 return dma_len > 0xFFFF ? 0xFFFF : dma_len;
252 static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
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.
264 (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
265 (void)scsi_esp_intr(irq, esp_chips[0]);
269 (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
270 (void)scsi_esp_intr(irq, esp_chips[1]);
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,
290 static int esp_mac_probe(struct platform_device *dev)
292 struct scsi_host_template *tpnt = &scsi_esp_template;
293 struct Scsi_Host *host;
296 struct mac_esp_priv *mep;
304 host = scsi_host_alloc(tpnt, sizeof(struct esp));
311 host->dma_boundary = PAGE_SIZE - 1;
312 esp = shost_priv(host);
315 esp->dev = &dev->dev;
317 esp->command_block = kzalloc(16, GFP_KERNEL);
318 if (!esp->command_block)
320 esp->command_block_dma = (dma_addr_t)esp->command_block;
323 host->this_id = esp->scsi_id;
324 esp->scsi_id_mask = 1 << esp->scsi_id;
326 mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
328 goto fail_free_command_block;
330 platform_set_drvdata(dev, mep);
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;
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);
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.
352 esp->cfreq = 25000000;
353 esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA3;
355 mep->pdma_regs = NULL;
358 esp->fifo_reg = esp->regs + ESP_FDATA * 16;
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;
369 printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
372 host->irq = IRQ_MAC_SCSI;
374 /* The request_irq() call is intended to succeed for the first device
375 * and fail for the second device.
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);
383 esp_chips[dev->id] = esp;
384 spin_unlock(&esp_chips_lock);
386 err = scsi_esp_register(esp);
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);
399 spin_unlock(&esp_chips_lock);
402 fail_free_command_block:
403 kfree(esp->command_block);
410 static int esp_mac_remove(struct platform_device *dev)
412 struct mac_esp_priv *mep = platform_get_drvdata(dev);
413 struct esp *esp = mep->esp;
414 unsigned int irq = esp->host->irq;
416 scsi_esp_unregister(esp);
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);
424 spin_unlock(&esp_chips_lock);
428 kfree(esp->command_block);
430 scsi_host_put(esp->host);
435 static struct platform_driver esp_mac_driver = {
436 .probe = esp_mac_probe,
437 .remove = esp_mac_remove,
439 .name = DRV_MODULE_NAME,
442 module_platform_driver(esp_mac_driver);
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);