xref: /linux/drivers/scsi/sgiwd93.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a) 
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 (davem@davemloft.net)
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 
34 struct 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 
43 struct 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 
53 static 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 
65 static inline
66 void 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 
103 static 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 
136 static 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 
166 void 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 }
174 EXPORT_SYMBOL_GPL(sgiwd93_reset);
175 
176 static 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 
195 static int sgiwd93_bus_reset(struct scsi_cmnd *cmd)
196 {
197 	/* FIXME perform bus-specific reset */
198 
199 	/* FIXME 2: kill this function, and let midlayer fallback
200 	   to the same result, calling wd33c93_host_reset() */
201 
202 	spin_lock_irq(cmd->device->host->host_lock);
203 	wd33c93_host_reset(cmd);
204 	spin_unlock_irq(cmd->device->host->host_lock);
205 
206 	return SUCCESS;
207 }
208 
209 /*
210  * Kludge alert - the SCSI code calls the abort and reset method with int
211  * arguments not with pointers.  So this is going to blow up beautyfully
212  * on 64-bit systems with memory outside the compat address spaces.
213  */
214 static struct scsi_host_template sgiwd93_template = {
215 	.module			= THIS_MODULE,
216 	.proc_name		= "SGIWD93",
217 	.name			= "SGI WD93",
218 	.queuecommand		= wd33c93_queuecommand,
219 	.eh_abort_handler	= wd33c93_abort,
220 	.eh_bus_reset_handler	= sgiwd93_bus_reset,
221 	.eh_host_reset_handler	= wd33c93_host_reset,
222 	.can_queue		= 16,
223 	.this_id		= 7,
224 	.sg_tablesize		= SG_ALL,
225 	.cmd_per_lun		= 8,
226 	.use_clustering		= DISABLE_CLUSTERING,
227 };
228 
229 static int sgiwd93_probe(struct platform_device *pdev)
230 {
231 	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
232 	unsigned char *wdregs = pd->wdregs;
233 	struct hpc3_scsiregs *hregs = pd->hregs;
234 	struct ip22_hostdata *hdata;
235 	struct Scsi_Host *host;
236 	wd33c93_regs regs;
237 	unsigned int unit = pd->unit;
238 	unsigned int irq = pd->irq;
239 	int err;
240 
241 	host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
242 	if (!host) {
243 		err = -ENOMEM;
244 		goto out;
245 	}
246 
247 	host->base = (unsigned long) hregs;
248 	host->irq = irq;
249 
250 	hdata = host_to_hostdata(host);
251 	hdata->dev = &pdev->dev;
252 	hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
253 					   &hdata->dma, GFP_KERNEL);
254 	if (!hdata->cpu) {
255 		printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
256 		       "host %d buffer.\n", unit);
257 		err = -ENOMEM;
258 		goto out_put;
259 	}
260 
261 	init_hpc_chain(hdata);
262 
263 	regs.SASR = wdregs + 3;
264 	regs.SCMD = wdregs + 7;
265 
266 	hdata->wh.no_sync = 0;
267 	hdata->wh.fast = 1;
268 	hdata->wh.dma_mode = CTRL_BURST;
269 
270 	wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
271 
272 	err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
273 	if (err) {
274 		printk(KERN_WARNING "sgiwd93: Could not register irq %d "
275 		       "for host %d.\n", irq, unit);
276 		goto out_free;
277 	}
278 
279 	platform_set_drvdata(pdev, host);
280 
281 	err = scsi_add_host(host, NULL);
282 	if (err)
283 		goto out_irq;
284 
285 	scsi_scan_host(host);
286 
287 	return 0;
288 
289 out_irq:
290 	free_irq(irq, host);
291 out_free:
292 	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
293 out_put:
294 	scsi_host_put(host);
295 out:
296 
297 	return err;
298 }
299 
300 static int __exit sgiwd93_remove(struct platform_device *pdev)
301 {
302 	struct Scsi_Host *host = platform_get_drvdata(pdev);
303 	struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
304 	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
305 
306 	scsi_remove_host(host);
307 	free_irq(pd->irq, host);
308 	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
309 	scsi_host_put(host);
310 	return 0;
311 }
312 
313 static struct platform_driver sgiwd93_driver = {
314 	.probe  = sgiwd93_probe,
315 	.remove = sgiwd93_remove,
316 	.driver = {
317 		.name   = "sgiwd93",
318 		.owner	= THIS_MODULE,
319 	}
320 };
321 
322 static int __init sgiwd93_module_init(void)
323 {
324 	return platform_driver_register(&sgiwd93_driver);
325 }
326 
327 static void __exit sgiwd93_module_exit(void)
328 {
329 	return platform_driver_unregister(&sgiwd93_driver);
330 }
331 
332 module_init(sgiwd93_module_init);
333 module_exit(sgiwd93_module_exit);
334 
335 MODULE_DESCRIPTION("SGI WD33C93 driver");
336 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
337 MODULE_LICENSE("GPL");
338 MODULE_ALIAS("platform:sgiwd93");
339