xref: /openbmc/linux/drivers/scsi/sgiwd93.c (revision c059ee9d) 
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/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <scsi/scsi_device.h>
34 #include <scsi/scsi_eh.h>
35 #include <scsi/scsi_tcq.h>
36 #include "wd33c93.h"
37 
38 struct ip22_hostdata {
39 	struct WD33C93_hostdata wh;
40 	dma_addr_t dma;
41 	void *cpu;
42 	struct device *dev;
43 };
44 
45 #define host_to_hostdata(host) ((struct ip22_hostdata *)((host)->hostdata))
46 
47 struct hpc_chunk {
48 	struct hpc_dma_desc desc;
49 	u32 _padding;	/* align to quadword boundary */
50 };
51 
52 /* space for hpc dma descriptors */
53 #define HPC_DMA_SIZE   PAGE_SIZE
54 
55 #define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
56 
57 static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
58 {
59 	struct Scsi_Host * host = dev_id;
60 	unsigned long flags;
61 
62 	spin_lock_irqsave(host->host_lock, flags);
63 	wd33c93_intr(host);
64 	spin_unlock_irqrestore(host->host_lock, flags);
65 
66 	return IRQ_HANDLED;
67 }
68 
69 static inline
70 void fill_hpc_entries(struct ip22_hostdata *hd, struct scsi_cmnd *cmd, int din)
71 {
72 	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
73 	unsigned long len = scsi_pointer->this_residual;
74 	void *addr = scsi_pointer->ptr;
75 	dma_addr_t physaddr;
76 	unsigned long count;
77 	struct hpc_chunk *hcp;
78 
79 	physaddr = dma_map_single(hd->dev, addr, len, DMA_DIR(din));
80 	scsi_pointer->dma_handle = physaddr;
81 	hcp = hd->cpu;
82 
83 	while (len) {
84 		/*
85 		 * even cntinfo could be up to 16383, without
86 		 * magic only 8192 works correctly
87 		 */
88 		count = len > 8192 ? 8192 : len;
89 		hcp->desc.pbuf = physaddr;
90 		hcp->desc.cntinfo = count;
91 		hcp++;
92 		len -= count;
93 		physaddr += count;
94 	}
95 
96 	/*
97 	 * To make sure, if we trip an HPC bug, that we transfer every single
98 	 * byte, we tag on an extra zero length dma descriptor at the end of
99 	 * the chain.
100 	 */
101 	hcp->desc.pbuf = 0;
102 	hcp->desc.cntinfo = HPCDMA_EOX;
103 	dma_sync_single_for_device(hd->dev, hd->dma,
104 		       (unsigned long)(hcp + 1) - (unsigned long)hd->cpu,
105 		       DMA_TO_DEVICE);
106 }
107 
108 static int dma_setup(struct scsi_cmnd *cmd, int datainp)
109 {
110 	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
111 	struct ip22_hostdata *hdata = host_to_hostdata(cmd->device->host);
112 	struct hpc3_scsiregs *hregs =
113 		(struct hpc3_scsiregs *) cmd->device->host->base;
114 
115 	pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hdata->cpu);
116 
117 	hdata->wh.dma_dir = datainp;
118 
119 	/*
120 	 * wd33c93 shouldn't pass us bogus dma_setups, but it does:-(  The
121 	 * other wd33c93 drivers deal with it the same way (which isn't that
122 	 * obvious).  IMHO a better fix would be, not to do these dma setups
123 	 * in the first place.
124 	 */
125 	if (scsi_pointer->ptr == NULL || scsi_pointer->this_residual == 0)
126 		return 1;
127 
128 	fill_hpc_entries(hdata, cmd, datainp);
129 
130 	pr_debug(" HPCGO\n");
131 
132 	/* Start up the HPC. */
133 	hregs->ndptr = hdata->dma;
134 	if (datainp)
135 		hregs->ctrl = HPC3_SCTRL_ACTIVE;
136 	else
137 		hregs->ctrl = HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR;
138 
139 	return 0;
140 }
141 
142 static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
143 		     int status)
144 {
145 	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(SCpnt);
146 	struct ip22_hostdata *hdata = host_to_hostdata(instance);
147 	struct hpc3_scsiregs *hregs;
148 
149 	if (!SCpnt)
150 		return;
151 
152 	if (scsi_pointer->ptr == NULL || scsi_pointer->this_residual == 0)
153 		return;
154 
155 	hregs = (struct hpc3_scsiregs *) SCpnt->device->host->base;
156 
157 	pr_debug("dma_stop: status<%d> ", status);
158 
159 	/* First stop the HPC and flush it's FIFO. */
160 	if (hdata->wh.dma_dir) {
161 		hregs->ctrl |= HPC3_SCTRL_FLUSH;
162 		while (hregs->ctrl & HPC3_SCTRL_ACTIVE)
163 			barrier();
164 	}
165 	hregs->ctrl = 0;
166 	dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
167 			 scsi_pointer->this_residual,
168 			 DMA_DIR(hdata->wh.dma_dir));
169 
170 	pr_debug("\n");
171 }
172 
173 void sgiwd93_reset(unsigned long base)
174 {
175 	struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) base;
176 
177 	hregs->ctrl = HPC3_SCTRL_CRESET;
178 	udelay(50);
179 	hregs->ctrl = 0;
180 }
181 EXPORT_SYMBOL_GPL(sgiwd93_reset);
182 
183 static inline void init_hpc_chain(struct ip22_hostdata *hdata)
184 {
185 	struct hpc_chunk *hcp = (struct hpc_chunk *)hdata->cpu;
186 	dma_addr_t dma = hdata->dma;
187 	unsigned long start, end;
188 
189 	start = (unsigned long) hcp;
190 	end = start + HPC_DMA_SIZE;
191 	while (start < end) {
192 		hcp->desc.pnext = (u32) (dma + sizeof(struct hpc_chunk));
193 		hcp->desc.cntinfo = HPCDMA_EOX;
194 		hcp++;
195 		dma += sizeof(struct hpc_chunk);
196 		start += sizeof(struct hpc_chunk);
197 	}
198 	hcp--;
199 	hcp->desc.pnext = hdata->dma;
200 }
201 
202 /*
203  * Kludge alert - the SCSI code calls the abort and reset method with int
204  * arguments not with pointers.  So this is going to blow up beautyfully
205  * on 64-bit systems with memory outside the compat address spaces.
206  */
207 static struct scsi_host_template sgiwd93_template = {
208 	.module			= THIS_MODULE,
209 	.proc_name		= "SGIWD93",
210 	.name			= "SGI WD93",
211 	.queuecommand		= wd33c93_queuecommand,
212 	.eh_abort_handler	= wd33c93_abort,
213 	.eh_host_reset_handler	= wd33c93_host_reset,
214 	.can_queue		= 16,
215 	.this_id		= 7,
216 	.sg_tablesize		= SG_ALL,
217 	.cmd_per_lun		= 8,
218 	.dma_boundary		= PAGE_SIZE - 1,
219 	.cmd_size		= sizeof(struct scsi_pointer),
220 };
221 
222 static int sgiwd93_probe(struct platform_device *pdev)
223 {
224 	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
225 	unsigned char *wdregs = pd->wdregs;
226 	struct hpc3_scsiregs *hregs = pd->hregs;
227 	struct ip22_hostdata *hdata;
228 	struct Scsi_Host *host;
229 	wd33c93_regs regs;
230 	unsigned int unit = pd->unit;
231 	unsigned int irq = pd->irq;
232 	int err;
233 
234 	host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
235 	if (!host) {
236 		err = -ENOMEM;
237 		goto out;
238 	}
239 
240 	host->base = (unsigned long) hregs;
241 	host->irq = irq;
242 
243 	hdata = host_to_hostdata(host);
244 	hdata->dev = &pdev->dev;
245 	hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
246 				&hdata->dma, DMA_TO_DEVICE, GFP_KERNEL);
247 	if (!hdata->cpu) {
248 		printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
249 		       "host %d buffer.\n", unit);
250 		err = -ENOMEM;
251 		goto out_put;
252 	}
253 
254 	init_hpc_chain(hdata);
255 
256 	regs.SASR = wdregs + 3;
257 	regs.SCMD = wdregs + 7;
258 
259 	hdata->wh.no_sync = 0;
260 	hdata->wh.fast = 1;
261 	hdata->wh.dma_mode = CTRL_BURST;
262 
263 	wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
264 
265 	err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
266 	if (err) {
267 		printk(KERN_WARNING "sgiwd93: Could not register irq %d "
268 		       "for host %d.\n", irq, unit);
269 		goto out_free;
270 	}
271 
272 	platform_set_drvdata(pdev, host);
273 
274 	err = scsi_add_host(host, NULL);
275 	if (err)
276 		goto out_irq;
277 
278 	scsi_scan_host(host);
279 
280 	return 0;
281 
282 out_irq:
283 	free_irq(irq, host);
284 out_free:
285 	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
286 			DMA_TO_DEVICE);
287 out_put:
288 	scsi_host_put(host);
289 out:
290 
291 	return err;
292 }
293 
294 static int sgiwd93_remove(struct platform_device *pdev)
295 {
296 	struct Scsi_Host *host = platform_get_drvdata(pdev);
297 	struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
298 	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
299 
300 	scsi_remove_host(host);
301 	free_irq(pd->irq, host);
302 	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
303 			DMA_TO_DEVICE);
304 	scsi_host_put(host);
305 	return 0;
306 }
307 
308 static struct platform_driver sgiwd93_driver = {
309 	.probe  = sgiwd93_probe,
310 	.remove = sgiwd93_remove,
311 	.driver = {
312 		.name   = "sgiwd93",
313 	}
314 };
315 
316 static int __init sgiwd93_module_init(void)
317 {
318 	return platform_driver_register(&sgiwd93_driver);
319 }
320 
321 static void __exit sgiwd93_module_exit(void)
322 {
323 	return platform_driver_unregister(&sgiwd93_driver);
324 }
325 
326 module_init(sgiwd93_module_init);
327 module_exit(sgiwd93_module_exit);
328 
329 MODULE_DESCRIPTION("SGI WD33C93 driver");
330 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
331 MODULE_LICENSE("GPL");
332 MODULE_ALIAS("platform:sgiwd93");
333