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
26struct 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
34static 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
53static 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
139static 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
200static const 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
216static 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
276fail_host:
277	free_irq(IRQ_AMIGA_PORTS, instance);
278fail_irq:
279	scsi_host_put(instance);
280fail_alloc:
281	release_mem_region(res->start, resource_size(res));
282	return error;
283}
284
285static void __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}
297
298static struct platform_driver amiga_a3000_scsi_driver = {
299	.remove_new = __exit_p(amiga_a3000_scsi_remove),
300	.driver   = {
301		.name	= "amiga-a3000-scsi",
302	},
303};
304
305module_platform_driver_probe(amiga_a3000_scsi_driver, amiga_a3000_scsi_probe);
306
307MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");
308MODULE_LICENSE("GPL");
309MODULE_ALIAS("platform:amiga-a3000-scsi");
310