xref: /openbmc/linux/drivers/scsi/a3000.c (revision e40573a4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/mm.h>
4 #include <linux/ioport.h>
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/spinlock.h>
8 #include <linux/interrupt.h>
9 #include <linux/platform_device.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/module.h>
12 
13 #include <asm/page.h>
14 #include <asm/amigaints.h>
15 #include <asm/amigahw.h>
16 
17 #include <scsi/scsi.h>
18 #include <scsi/scsi_cmnd.h>
19 #include <scsi/scsi_device.h>
20 #include <scsi/scsi_eh.h>
21 #include <scsi/scsi_tcq.h>
22 #include "wd33c93.h"
23 #include "a3000.h"
24 
25 
26 struct a3000_hostdata {
27 	struct WD33C93_hostdata wh;
28 	struct a3000_scsiregs *regs;
29 	struct device *dev;
30 };
31 
32 #define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
33 
34 static irqreturn_t a3000_intr(int irq, void *data)
35 {
36 	struct Scsi_Host *instance = data;
37 	struct a3000_hostdata *hdata = shost_priv(instance);
38 	unsigned int status = hdata->regs->ISTR;
39 	unsigned long flags;
40 
41 	if (!(status & ISTR_INT_P))
42 		return IRQ_NONE;
43 	if (status & ISTR_INTS) {
44 		spin_lock_irqsave(instance->host_lock, flags);
45 		wd33c93_intr(instance);
46 		spin_unlock_irqrestore(instance->host_lock, flags);
47 		return IRQ_HANDLED;
48 	}
49 	pr_warn("Non-serviced A3000 SCSI-interrupt? ISTR = %02x\n", status);
50 	return IRQ_NONE;
51 }
52 
53 static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
54 {
55 	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
56 	unsigned long len = scsi_pointer->this_residual;
57 	struct Scsi_Host *instance = cmd->device->host;
58 	struct a3000_hostdata *hdata = shost_priv(instance);
59 	struct WD33C93_hostdata *wh = &hdata->wh;
60 	struct a3000_scsiregs *regs = hdata->regs;
61 	unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
62 	dma_addr_t addr;
63 
64 	addr = dma_map_single(hdata->dev, scsi_pointer->ptr,
65 			      len, DMA_DIR(dir_in));
66 	if (dma_mapping_error(hdata->dev, addr)) {
67 		dev_warn(hdata->dev, "cannot map SCSI data block %p\n",
68 			 scsi_pointer->ptr);
69 		return 1;
70 	}
71 	scsi_pointer->dma_handle = addr;
72 
73 	/*
74 	 * if the physical address has the wrong alignment, or if
75 	 * physical address is bad, or if it is a write and at the
76 	 * end of a physical memory chunk, then allocate a bounce
77 	 * buffer
78 	 * MSch 20220629 - only wrong alignment tested - bounce
79 	 * buffer returned by kmalloc is guaranteed to be aligned
80 	 */
81 	if (addr & A3000_XFER_MASK) {
82 		WARN_ONCE(1, "Invalid alignment for DMA!");
83 		/* drop useless mapping */
84 		dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
85 				 scsi_pointer->this_residual,
86 				 DMA_DIR(dir_in));
87 
88 		wh->dma_bounce_len = (scsi_pointer->this_residual + 511) & ~0x1ff;
89 		wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len,
90 						GFP_KERNEL);
91 
92 		/* can't allocate memory; use PIO */
93 		if (!wh->dma_bounce_buffer) {
94 			wh->dma_bounce_len = 0;
95 			scsi_pointer->dma_handle = (dma_addr_t) NULL;
96 			return 1;
97 		}
98 
99 		if (!dir_in) {
100 			/* copy to bounce buffer for a write */
101 			memcpy(wh->dma_bounce_buffer, scsi_pointer->ptr,
102 			       scsi_pointer->this_residual);
103 		}
104 
105 		addr = dma_map_single(hdata->dev, scsi_pointer->ptr,
106 				      len, DMA_DIR(dir_in));
107 		if (dma_mapping_error(hdata->dev, addr)) {
108 			dev_warn(hdata->dev,
109 				 "cannot map SCSI data block %p\n",
110 				 scsi_pointer->ptr);
111 			return 1;
112 		}
113 		scsi_pointer->dma_handle = addr;
114 	}
115 
116 	/* setup dma direction */
117 	if (!dir_in)
118 		cntr |= CNTR_DDIR;
119 
120 	/* remember direction */
121 	wh->dma_dir = dir_in;
122 
123 	regs->CNTR = cntr;
124 
125 	/* setup DMA *physical* address */
126 	regs->ACR = addr;
127 
128 	/* no more cache flush here - dma_map_single() takes care */
129 
130 	/* start DMA */
131 	mb();			/* make sure setup is completed */
132 	regs->ST_DMA = 1;
133 	mb();			/* make sure DMA has started before next IO */
134 
135 	/* return success */
136 	return 0;
137 }
138 
139 static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
140 		     int status)
141 {
142 	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(SCpnt);
143 	struct a3000_hostdata *hdata = shost_priv(instance);
144 	struct WD33C93_hostdata *wh = &hdata->wh;
145 	struct a3000_scsiregs *regs = hdata->regs;
146 
147 	/* disable SCSI interrupts */
148 	unsigned short cntr = CNTR_PDMD;
149 
150 	if (!wh->dma_dir)
151 		cntr |= CNTR_DDIR;
152 
153 	regs->CNTR = cntr;
154 	mb();			/* make sure CNTR is updated before next IO */
155 
156 	/* flush if we were reading */
157 	if (wh->dma_dir) {
158 		regs->FLUSH = 1;
159 		mb();		/* don't allow prefetch */
160 		while (!(regs->ISTR & ISTR_FE_FLG))
161 			barrier();
162 		mb();		/* no IO until FLUSH is done */
163 	}
164 
165 	/* clear a possible interrupt */
166 	/* I think that this CINT is only necessary if you are
167 	 * using the terminal count features.   HM 7 Mar 1994
168 	 */
169 	regs->CINT = 1;
170 
171 	/* stop DMA */
172 	regs->SP_DMA = 1;
173 	mb();			/* make sure DMA is stopped before next IO */
174 
175 	/* restore the CONTROL bits (minus the direction flag) */
176 	regs->CNTR = CNTR_PDMD | CNTR_INTEN;
177 	mb();			/* make sure CNTR is updated before next IO */
178 
179 	dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
180 			 scsi_pointer->this_residual,
181 			 DMA_DIR(wh->dma_dir));
182 
183 	/* copy from a bounce buffer, if necessary */
184 	if (status && wh->dma_bounce_buffer) {
185 		if (SCpnt) {
186 			if (wh->dma_dir && SCpnt)
187 				memcpy(scsi_pointer->ptr, wh->dma_bounce_buffer,
188 				       scsi_pointer->this_residual);
189 			kfree(wh->dma_bounce_buffer);
190 			wh->dma_bounce_buffer = NULL;
191 			wh->dma_bounce_len = 0;
192 		} else {
193 			kfree(wh->dma_bounce_buffer);
194 			wh->dma_bounce_buffer = NULL;
195 			wh->dma_bounce_len = 0;
196 		}
197 	}
198 }
199 
200 static struct scsi_host_template amiga_a3000_scsi_template = {
201 	.module			= THIS_MODULE,
202 	.name			= "Amiga 3000 built-in SCSI",
203 	.show_info		= wd33c93_show_info,
204 	.write_info		= wd33c93_write_info,
205 	.proc_name		= "A3000",
206 	.queuecommand		= wd33c93_queuecommand,
207 	.eh_abort_handler	= wd33c93_abort,
208 	.eh_host_reset_handler	= wd33c93_host_reset,
209 	.can_queue		= CAN_QUEUE,
210 	.this_id		= 7,
211 	.sg_tablesize		= SG_ALL,
212 	.cmd_per_lun		= CMD_PER_LUN,
213 	.cmd_size		= sizeof(struct scsi_pointer),
214 };
215 
216 static int __init amiga_a3000_scsi_probe(struct platform_device *pdev)
217 {
218 	struct resource *res;
219 	struct Scsi_Host *instance;
220 	int error;
221 	struct a3000_scsiregs *regs;
222 	wd33c93_regs wdregs;
223 	struct a3000_hostdata *hdata;
224 
225 	if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32))) {
226 		dev_warn(&pdev->dev, "cannot use 32 bit DMA\n");
227 		return -ENODEV;
228 	}
229 
230 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
231 	if (!res)
232 		return -ENODEV;
233 
234 	if (!request_mem_region(res->start, resource_size(res), "wd33c93"))
235 		return -EBUSY;
236 
237 	instance = scsi_host_alloc(&amiga_a3000_scsi_template,
238 				   sizeof(struct a3000_hostdata));
239 	if (!instance) {
240 		error = -ENOMEM;
241 		goto fail_alloc;
242 	}
243 
244 	instance->irq = IRQ_AMIGA_PORTS;
245 
246 	regs = ZTWO_VADDR(res->start);
247 	regs->DAWR = DAWR_A3000;
248 
249 	wdregs.SASR = &regs->SASR;
250 	wdregs.SCMD = &regs->SCMD;
251 
252 	hdata = shost_priv(instance);
253 	hdata->dev = &pdev->dev;
254 	hdata->wh.no_sync = 0xff;
255 	hdata->wh.fast = 0;
256 	hdata->wh.dma_mode = CTRL_DMA;
257 	hdata->regs = regs;
258 
259 	wd33c93_init(instance, wdregs, dma_setup, dma_stop, WD33C93_FS_12_15);
260 	error = request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED,
261 			    "A3000 SCSI", instance);
262 	if (error)
263 		goto fail_irq;
264 
265 	regs->CNTR = CNTR_PDMD | CNTR_INTEN;
266 
267 	error = scsi_add_host(instance, NULL);
268 	if (error)
269 		goto fail_host;
270 
271 	platform_set_drvdata(pdev, instance);
272 
273 	scsi_scan_host(instance);
274 	return 0;
275 
276 fail_host:
277 	free_irq(IRQ_AMIGA_PORTS, instance);
278 fail_irq:
279 	scsi_host_put(instance);
280 fail_alloc:
281 	release_mem_region(res->start, resource_size(res));
282 	return error;
283 }
284 
285 static int __exit amiga_a3000_scsi_remove(struct platform_device *pdev)
286 {
287 	struct Scsi_Host *instance = platform_get_drvdata(pdev);
288 	struct a3000_hostdata *hdata = shost_priv(instance);
289 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
290 
291 	hdata->regs->CNTR = 0;
292 	scsi_remove_host(instance);
293 	free_irq(IRQ_AMIGA_PORTS, instance);
294 	scsi_host_put(instance);
295 	release_mem_region(res->start, resource_size(res));
296 	return 0;
297 }
298 
299 static struct platform_driver amiga_a3000_scsi_driver = {
300 	.remove = __exit_p(amiga_a3000_scsi_remove),
301 	.driver   = {
302 		.name	= "amiga-a3000-scsi",
303 	},
304 };
305 
306 module_platform_driver_probe(amiga_a3000_scsi_driver, amiga_a3000_scsi_probe);
307 
308 MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");
309 MODULE_LICENSE("GPL");
310 MODULE_ALIAS("platform:amiga-a3000-scsi");
311