summaryrefslogtreecommitdiff
path: root/drivers/scsi/sgiwd93.c
blob: 57d5dff62f6364692c96c1e88605eb9dc7e3ed4d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
 * Copyright (C) 2001 Florian Lohoff (flo@rfc822.org)
 * Copyright (C) 2003, 07 Ralf Baechle (ralf@linux-mips.org)
 * 
 * (In all truth, Jed Schimmel wrote all this code.)
 */

#undef DEBUG

#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>

#include <asm/sgi/hpc3.h>
#include <asm/sgi/ip22.h>
#include <asm/sgi/wd.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_tcq.h>
#include "wd33c93.h"

struct ip22_hostdata {
	struct WD33C93_hostdata wh;
	dma_addr_t dma;
	void *cpu;
	struct device *dev;
};

#define host_to_hostdata(host) ((struct ip22_hostdata *)((host)->hostdata))

struct hpc_chunk {
	struct hpc_dma_desc desc;
	u32 _padding;	/* align to quadword boundary */
};

/* space for hpc dma descriptors */
#define HPC_DMA_SIZE   PAGE_SIZE

#define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)

static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
{
	struct Scsi_Host * host = dev_id;
	unsigned long flags;

	spin_lock_irqsave(host->host_lock, flags);
	wd33c93_intr(host);
	spin_unlock_irqrestore(host->host_lock, flags);

	return IRQ_HANDLED;
}

static inline
void fill_hpc_entries(struct ip22_hostdata *hd, struct scsi_cmnd *cmd, int din)
{
	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
	unsigned long len = scsi_pointer->this_residual;
	void *addr = scsi_pointer->ptr;
	dma_addr_t physaddr;
	unsigned long count;
	struct hpc_chunk *hcp;

	physaddr = dma_map_single(hd->dev, addr, len, DMA_DIR(din));
	scsi_pointer->dma_handle = physaddr;
	hcp = hd->cpu;

	while (len) {
		/*
		 * even cntinfo could be up to 16383, without
		 * magic only 8192 works correctly
		 */
		count = len > 8192 ? 8192 : len;
		hcp->desc.pbuf = physaddr;
		hcp->desc.cntinfo = count;
		hcp++;
		len -= count;
		physaddr += count;
	}

	/*
	 * To make sure, if we trip an HPC bug, that we transfer every single
	 * byte, we tag on an extra zero length dma descriptor at the end of
	 * the chain.
	 */
	hcp->desc.pbuf = 0;
	hcp->desc.cntinfo = HPCDMA_EOX;
	dma_sync_single_for_device(hd->dev, hd->dma,
		       (unsigned long)(hcp + 1) - (unsigned long)hd->cpu,
		       DMA_TO_DEVICE);
}

static int dma_setup(struct scsi_cmnd *cmd, int datainp)
{
	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
	struct ip22_hostdata *hdata = host_to_hostdata(cmd->device->host);
	struct hpc3_scsiregs *hregs =
		(struct hpc3_scsiregs *) cmd->device->host->base;

	pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hdata->cpu);

	hdata->wh.dma_dir = datainp;

	/*
	 * wd33c93 shouldn't pass us bogus dma_setups, but it does:-(  The
	 * other wd33c93 drivers deal with it the same way (which isn't that
	 * obvious).  IMHO a better fix would be, not to do these dma setups
	 * in the first place.
	 */
	if (scsi_pointer->ptr == NULL || scsi_pointer->this_residual == 0)
		return 1;

	fill_hpc_entries(hdata, cmd, datainp);

	pr_debug(" HPCGO\n");

	/* Start up the HPC. */
	hregs->ndptr = hdata->dma;
	if (datainp)
		hregs->ctrl = HPC3_SCTRL_ACTIVE;
	else
		hregs->ctrl = HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR;

	return 0;
}

static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
		     int status)
{
	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(SCpnt);
	struct ip22_hostdata *hdata = host_to_hostdata(instance);
	struct hpc3_scsiregs *hregs;

	if (!SCpnt)
		return;

	if (scsi_pointer->ptr == NULL || scsi_pointer->this_residual == 0)
		return;

	hregs = (struct hpc3_scsiregs *) SCpnt->device->host->base;

	pr_debug("dma_stop: status<%d> ", status);

	/* First stop the HPC and flush it's FIFO. */
	if (hdata->wh.dma_dir) {
		hregs->ctrl |= HPC3_SCTRL_FLUSH;
		while (hregs->ctrl & HPC3_SCTRL_ACTIVE)
			barrier();
	}
	hregs->ctrl = 0;
	dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
			 scsi_pointer->this_residual,
			 DMA_DIR(hdata->wh.dma_dir));

	pr_debug("\n");
}

void sgiwd93_reset(unsigned long base)
{
	struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) base;

	hregs->ctrl = HPC3_SCTRL_CRESET;
	udelay(50);
	hregs->ctrl = 0;
}
EXPORT_SYMBOL_GPL(sgiwd93_reset);

static inline void init_hpc_chain(struct ip22_hostdata *hdata)
{
	struct hpc_chunk *hcp = (struct hpc_chunk *)hdata->cpu;
	dma_addr_t dma = hdata->dma;
	unsigned long start, end;

	start = (unsigned long) hcp;
	end = start + HPC_DMA_SIZE;
	while (start < end) {
		hcp->desc.pnext = (u32) (dma + sizeof(struct hpc_chunk));
		hcp->desc.cntinfo = HPCDMA_EOX;
		hcp++;
		dma += sizeof(struct hpc_chunk);
		start += sizeof(struct hpc_chunk);
	}
	hcp--;
	hcp->desc.pnext = hdata->dma;
}

/*
 * Kludge alert - the SCSI code calls the abort and reset method with int
 * arguments not with pointers.  So this is going to blow up beautyfully
 * on 64-bit systems with memory outside the compat address spaces.
 */
static struct scsi_host_template sgiwd93_template = {
	.module			= THIS_MODULE,
	.proc_name		= "SGIWD93",
	.name			= "SGI WD93",
	.queuecommand		= wd33c93_queuecommand,
	.eh_abort_handler	= wd33c93_abort,
	.eh_host_reset_handler	= wd33c93_host_reset,
	.can_queue		= 16,
	.this_id		= 7,
	.sg_tablesize		= SG_ALL,
	.cmd_per_lun		= 8,
	.dma_boundary		= PAGE_SIZE - 1,
	.cmd_size		= sizeof(struct scsi_pointer),
};

static int sgiwd93_probe(struct platform_device *pdev)
{
	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
	unsigned char *wdregs = pd->wdregs;
	struct hpc3_scsiregs *hregs = pd->hregs;
	struct ip22_hostdata *hdata;
	struct Scsi_Host *host;
	wd33c93_regs regs;
	unsigned int unit = pd->unit;
	unsigned int irq = pd->irq;
	int err;

	host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
	if (!host) {
		err = -ENOMEM;
		goto out;
	}

	host->base = (unsigned long) hregs;
	host->irq = irq;

	hdata = host_to_hostdata(host);
	hdata->dev = &pdev->dev;
	hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
				&hdata->dma, DMA_TO_DEVICE, GFP_KERNEL);
	if (!hdata->cpu) {
		printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
		       "host %d buffer.\n", unit);
		err = -ENOMEM;
		goto out_put;
	}

	init_hpc_chain(hdata);

	regs.SASR = wdregs + 3;
	regs.SCMD = wdregs + 7;

	hdata->wh.no_sync = 0;
	hdata->wh.fast = 1;
	hdata->wh.dma_mode = CTRL_BURST;

	wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));

	err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
	if (err) {
		printk(KERN_WARNING "sgiwd93: Could not register irq %d "
		       "for host %d.\n", irq, unit);
		goto out_free;
	}

	platform_set_drvdata(pdev, host);

	err = scsi_add_host(host, NULL);
	if (err)
		goto out_irq;

	scsi_scan_host(host);

	return 0;

out_irq:
	free_irq(irq, host);
out_free:
	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
			DMA_TO_DEVICE);
out_put:
	scsi_host_put(host);
out:

	return err;
}

static int sgiwd93_remove(struct platform_device *pdev)
{
	struct Scsi_Host *host = platform_get_drvdata(pdev);
	struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;

	scsi_remove_host(host);
	free_irq(pd->irq, host);
	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
			DMA_TO_DEVICE);
	scsi_host_put(host);
	return 0;
}

static struct platform_driver sgiwd93_driver = {
	.probe  = sgiwd93_probe,
	.remove = sgiwd93_remove,
	.driver = {
		.name   = "sgiwd93",
	}
};

static int __init sgiwd93_module_init(void)
{
	return platform_driver_register(&sgiwd93_driver);
}

static void __exit sgiwd93_module_exit(void)
{
	return platform_driver_unregister(&sgiwd93_driver);
}

module_init(sgiwd93_module_init);
module_exit(sgiwd93_module_exit);

MODULE_DESCRIPTION("SGI WD33C93 driver");
MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:sgiwd93");