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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/scsi/
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
7 * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
8 * Copyright (C) 2001 Florian Lohoff (flo@rfc822.org)
9 * Copyright (C) 2003, 07 Ralf Baechle (ralf@linux-mips.org)
10 *
11 * (In all truth, Jed Schimmel wrote all this code.)
12 */
13
14#undef DEBUG
15
16#include <linux/delay.h>
17#include <linux/dma-mapping.h>
18#include <linux/gfp.h>
19#include <linux/interrupt.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/types.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/spinlock.h>
26
27#include <asm/sgi/hpc3.h>
28#include <asm/sgi/ip22.h>
29#include <asm/sgi/wd.h>
30
31#include "scsi.h"
32#include "wd33c93.h"
33
34struct ip22_hostdata {
35	struct WD33C93_hostdata wh;
36	dma_addr_t dma;
37	void *cpu;
38	struct device *dev;
39};
40
41#define host_to_hostdata(host) ((struct ip22_hostdata *)((host)->hostdata))
42
43struct hpc_chunk {
44	struct hpc_dma_desc desc;
45	u32 _padding;	/* align to quadword boundary */
46};
47
48/* space for hpc dma descriptors */
49#define HPC_DMA_SIZE   PAGE_SIZE
50
51#define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
52
53static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
54{
55	struct Scsi_Host * host = dev_id;
56	unsigned long flags;
57
58	spin_lock_irqsave(host->host_lock, flags);
59	wd33c93_intr(host);
60	spin_unlock_irqrestore(host->host_lock, flags);
61
62	return IRQ_HANDLED;
63}
64
65static inline
66void fill_hpc_entries(struct ip22_hostdata *hd, struct scsi_cmnd *cmd, int din)
67{
68	unsigned long len = cmd->SCp.this_residual;
69	void *addr = cmd->SCp.ptr;
70	dma_addr_t physaddr;
71	unsigned long count;
72	struct hpc_chunk *hcp;
73
74	physaddr = dma_map_single(hd->dev, addr, len, DMA_DIR(din));
75	cmd->SCp.dma_handle = physaddr;
76	hcp = hd->cpu;
77
78	while (len) {
79		/*
80		 * even cntinfo could be up to 16383, without
81		 * magic only 8192 works correctly
82		 */
83		count = len > 8192 ? 8192 : len;
84		hcp->desc.pbuf = physaddr;
85		hcp->desc.cntinfo = count;
86		hcp++;
87		len -= count;
88		physaddr += count;
89	}
90
91	/*
92	 * To make sure, if we trip an HPC bug, that we transfer every single
93	 * byte, we tag on an extra zero length dma descriptor at the end of
94	 * the chain.
95	 */
96	hcp->desc.pbuf = 0;
97	hcp->desc.cntinfo = HPCDMA_EOX;
98	dma_cache_sync(hd->dev, hd->cpu,
99		       (unsigned long)(hcp + 1) - (unsigned long)hd->cpu,
100		       DMA_TO_DEVICE);
101}
102
103static int dma_setup(struct scsi_cmnd *cmd, int datainp)
104{
105	struct ip22_hostdata *hdata = host_to_hostdata(cmd->device->host);
106	struct hpc3_scsiregs *hregs =
107		(struct hpc3_scsiregs *) cmd->device->host->base;
108
109	pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hdata->cpu);
110
111	hdata->wh.dma_dir = datainp;
112
113	/*
114	 * wd33c93 shouldn't pass us bogus dma_setups, but it does:-(  The
115	 * other wd33c93 drivers deal with it the same way (which isn't that
116	 * obvious).  IMHO a better fix would be, not to do these dma setups
117	 * in the first place.
118	 */
119	if (cmd->SCp.ptr == NULL || cmd->SCp.this_residual == 0)
120		return 1;
121
122	fill_hpc_entries(hdata, cmd, datainp);
123
124	pr_debug(" HPCGO\n");
125
126	/* Start up the HPC. */
127	hregs->ndptr = hdata->dma;
128	if (datainp)
129		hregs->ctrl = HPC3_SCTRL_ACTIVE;
130	else
131		hregs->ctrl = HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR;
132
133	return 0;
134}
135
136static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
137		     int status)
138{
139	struct ip22_hostdata *hdata = host_to_hostdata(instance);
140	struct hpc3_scsiregs *hregs;
141
142	if (!SCpnt)
143		return;
144
145	if (SCpnt->SCp.ptr == NULL || SCpnt->SCp.this_residual == 0)
146		return;
147
148	hregs = (struct hpc3_scsiregs *) SCpnt->device->host->base;
149
150	pr_debug("dma_stop: status<%d> ", status);
151
152	/* First stop the HPC and flush it's FIFO. */
153	if (hdata->wh.dma_dir) {
154		hregs->ctrl |= HPC3_SCTRL_FLUSH;
155		while (hregs->ctrl & HPC3_SCTRL_ACTIVE)
156			barrier();
157	}
158	hregs->ctrl = 0;
159	dma_unmap_single(hdata->dev, SCpnt->SCp.dma_handle,
160			 SCpnt->SCp.this_residual,
161			 DMA_DIR(hdata->wh.dma_dir));
162
163	pr_debug("\n");
164}
165
166void sgiwd93_reset(unsigned long base)
167{
168	struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) base;
169
170	hregs->ctrl = HPC3_SCTRL_CRESET;
171	udelay(50);
172	hregs->ctrl = 0;
173}
174EXPORT_SYMBOL_GPL(sgiwd93_reset);
175
176static inline void init_hpc_chain(struct ip22_hostdata *hdata)
177{
178	struct hpc_chunk *hcp = (struct hpc_chunk *)hdata->cpu;
179	dma_addr_t dma = hdata->dma;
180	unsigned long start, end;
181
182	start = (unsigned long) hcp;
183	end = start + HPC_DMA_SIZE;
184	while (start < end) {
185		hcp->desc.pnext = (u32) (dma + sizeof(struct hpc_chunk));
186		hcp->desc.cntinfo = HPCDMA_EOX;
187		hcp++;
188		dma += sizeof(struct hpc_chunk);
189		start += sizeof(struct hpc_chunk);
190	};
191	hcp--;
192	hcp->desc.pnext = hdata->dma;
193}
194
195static int sgiwd93_bus_reset(struct scsi_cmnd *cmd)
196{
197
198
199	spin_lock_irq(cmd->device->host->host_lock);
200	wd33c93_host_reset(cmd);
201	spin_unlock_irq(cmd->device->host->host_lock);
202
203	return SUCCESS;
204}
205
206/*
207 * Kludge alert - the SCSI code calls the abort and reset method with int
208 * arguments not with pointers.  So this is going to blow up beautyfully
209 * on 64-bit systems with memory outside the compat address spaces.
210 */
211static struct scsi_host_template sgiwd93_template = {
212	.module			= THIS_MODULE,
213	.proc_name		= "SGIWD93",
214	.name			= "SGI WD93",
215	.queuecommand		= wd33c93_queuecommand,
216	.eh_abort_handler	= wd33c93_abort,
217	.eh_bus_reset_handler	= sgiwd93_bus_reset,
218	.eh_host_reset_handler	= wd33c93_host_reset,
219	.can_queue		= 16,
220	.this_id		= 7,
221	.sg_tablesize		= SG_ALL,
222	.cmd_per_lun		= 8,
223	.use_clustering		= DISABLE_CLUSTERING,
224};
225
226static int __devinit sgiwd93_probe(struct platform_device *pdev)
227{
228	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
229	unsigned char *wdregs = pd->wdregs;
230	struct hpc3_scsiregs *hregs = pd->hregs;
231	struct ip22_hostdata *hdata;
232	struct Scsi_Host *host;
233	wd33c93_regs regs;
234	unsigned int unit = pd->unit;
235	unsigned int irq = pd->irq;
236	int err;
237
238	host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
239	if (!host) {
240		err = -ENOMEM;
241		goto out;
242	}
243
244	host->base = (unsigned long) hregs;
245	host->irq = irq;
246
247	hdata = host_to_hostdata(host);
248	hdata->dev = &pdev->dev;
249	hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
250					   &hdata->dma, GFP_KERNEL);
251	if (!hdata->cpu) {
252		printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
253		       "host %d buffer.\n", unit);
254		err = -ENOMEM;
255		goto out_put;
256	}
257
258	init_hpc_chain(hdata);
259
260	regs.SASR = wdregs + 3;
261	regs.SCMD = wdregs + 7;
262
263	hdata->wh.no_sync = 0;
264	hdata->wh.fast = 1;
265	hdata->wh.dma_mode = CTRL_BURST;
266
267	wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
268
269	err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
270	if (err) {
271		printk(KERN_WARNING "sgiwd93: Could not register irq %d "
272		       "for host %d.\n", irq, unit);
273		goto out_free;
274	}
275
276	platform_set_drvdata(pdev, host);
277
278	err = scsi_add_host(host, NULL);
279	if (err)
280		goto out_irq;
281
282	scsi_scan_host(host);
283
284	return 0;
285
286out_irq:
287	free_irq(irq, host);
288out_free:
289	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
290out_put:
291	scsi_host_put(host);
292out:
293
294	return err;
295}
296
297static int __exit sgiwd93_remove(struct platform_device *pdev)
298{
299	struct Scsi_Host *host = platform_get_drvdata(pdev);
300	struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
301	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
302
303	scsi_remove_host(host);
304	free_irq(pd->irq, host);
305	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
306	scsi_host_put(host);
307	return 0;
308}
309
310static struct platform_driver sgiwd93_driver = {
311	.probe  = sgiwd93_probe,
312	.remove = __devexit_p(sgiwd93_remove),
313	.driver = {
314		.name   = "sgiwd93",
315		.owner	= THIS_MODULE,
316	}
317};
318
319static int __init sgiwd93_module_init(void)
320{
321	return platform_driver_register(&sgiwd93_driver);
322}
323
324static void __exit sgiwd93_module_exit(void)
325{
326	return platform_driver_unregister(&sgiwd93_driver);
327}
328
329module_init(sgiwd93_module_init);
330module_exit(sgiwd93_module_exit);
331
332MODULE_DESCRIPTION("SGI WD33C93 driver");
333MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
334MODULE_LICENSE("GPL");
335MODULE_ALIAS("platform:sgiwd93");
336