xref: /openbmc/linux/drivers/scsi/sgiwd93.c (revision 64c70b1c) 
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 
34 struct ip22_hostdata {
35 	struct WD33C93_hostdata wh;
36 	struct hpc_data {
37 		dma_addr_t      dma;
38 		void		*cpu;
39 	} hd;
40 };
41 
42 #define host_to_hostdata(host) ((struct ip22_hostdata *)((host)->hostdata))
43 
44 struct hpc_chunk {
45 	struct hpc_dma_desc desc;
46 	u32 _padding;	/* align to quadword boundary */
47 };
48 
49 static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
50 {
51 	struct Scsi_Host * host = dev_id;
52 	unsigned long flags;
53 
54 	spin_lock_irqsave(host->host_lock, flags);
55 	wd33c93_intr(host);
56 	spin_unlock_irqrestore(host->host_lock, flags);
57 
58 	return IRQ_HANDLED;
59 }
60 
61 static inline
62 void fill_hpc_entries(struct hpc_chunk *hcp, struct scsi_cmnd *cmd, int datainp)
63 {
64 	unsigned long len = cmd->SCp.this_residual;
65 	void *addr = cmd->SCp.ptr;
66 	dma_addr_t physaddr;
67 	unsigned long count;
68 
69 	physaddr = dma_map_single(NULL, addr, len, cmd->sc_data_direction);
70 	cmd->SCp.dma_handle = physaddr;
71 
72 	while (len) {
73 		/*
74 		 * even cntinfo could be up to 16383, without
75 		 * magic only 8192 works correctly
76 		 */
77 		count = len > 8192 ? 8192 : len;
78 		hcp->desc.pbuf = physaddr;
79 		hcp->desc.cntinfo = count;
80 		hcp++;
81 		len -= count;
82 		physaddr += count;
83 	}
84 
85 	/*
86 	 * To make sure, if we trip an HPC bug, that we transfer every single
87 	 * byte, we tag on an extra zero length dma descriptor at the end of
88 	 * the chain.
89 	 */
90 	hcp->desc.pbuf = 0;
91 	hcp->desc.cntinfo = HPCDMA_EOX;
92 }
93 
94 static int dma_setup(struct scsi_cmnd *cmd, int datainp)
95 {
96 	struct ip22_hostdata *hdata = host_to_hostdata(cmd->device->host);
97 	struct hpc3_scsiregs *hregs =
98 		(struct hpc3_scsiregs *) cmd->device->host->base;
99 	struct hpc_chunk *hcp = (struct hpc_chunk *) hdata->hd.cpu;
100 
101 	pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hcp);
102 
103 	hdata->wh.dma_dir = datainp;
104 
105 	/*
106 	 * wd33c93 shouldn't pass us bogus dma_setups, but it does:-(  The
107 	 * other wd33c93 drivers deal with it the same way (which isn't that
108 	 * obvious).  IMHO a better fix would be, not to do these dma setups
109 	 * in the first place.
110 	 */
111 	if (cmd->SCp.ptr == NULL || cmd->SCp.this_residual == 0)
112 		return 1;
113 
114 	fill_hpc_entries(hcp, cmd, datainp);
115 
116 	pr_debug(" HPCGO\n");
117 
118 	/* Start up the HPC. */
119 	hregs->ndptr = hdata->hd.dma;
120 	if (datainp)
121 		hregs->ctrl = HPC3_SCTRL_ACTIVE;
122 	else
123 		hregs->ctrl = HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR;
124 
125 	return 0;
126 }
127 
128 static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
129 		     int status)
130 {
131 	struct ip22_hostdata *hdata = host_to_hostdata(instance);
132 	struct hpc3_scsiregs *hregs;
133 
134 	if (!SCpnt)
135 		return;
136 
137 	hregs = (struct hpc3_scsiregs *) SCpnt->device->host->base;
138 
139 	pr_debug("dma_stop: status<%d> ", status);
140 
141 	/* First stop the HPC and flush it's FIFO. */
142 	if (hdata->wh.dma_dir) {
143 		hregs->ctrl |= HPC3_SCTRL_FLUSH;
144 		while (hregs->ctrl & HPC3_SCTRL_ACTIVE)
145 			barrier();
146 	}
147 	hregs->ctrl = 0;
148 	dma_unmap_single(NULL, SCpnt->SCp.dma_handle, SCpnt->SCp.this_residual,
149 	                 SCpnt->sc_data_direction);
150 
151 	pr_debug("\n");
152 }
153 
154 void sgiwd93_reset(unsigned long base)
155 {
156 	struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) base;
157 
158 	hregs->ctrl = HPC3_SCTRL_CRESET;
159 	udelay(50);
160 	hregs->ctrl = 0;
161 }
162 
163 static inline void init_hpc_chain(struct hpc_data *hd)
164 {
165 	struct hpc_chunk *hcp = (struct hpc_chunk *) hd->cpu;
166 	struct hpc_chunk *dma = (struct hpc_chunk *) hd->dma;
167 	unsigned long start, end;
168 
169 	start = (unsigned long) hcp;
170 	end = start + PAGE_SIZE;
171 	while (start < end) {
172 		hcp->desc.pnext = (u32) (dma + 1);
173 		hcp->desc.cntinfo = HPCDMA_EOX;
174 		hcp++; dma++;
175 		start += sizeof(struct hpc_chunk);
176 	};
177 	hcp--;
178 	hcp->desc.pnext = hd->dma;
179 }
180 
181 static int sgiwd93_bus_reset(struct scsi_cmnd *cmd)
182 {
183 	/* FIXME perform bus-specific reset */
184 
185 	/* FIXME 2: kill this function, and let midlayer fallback
186 	   to the same result, calling wd33c93_host_reset() */
187 
188 	spin_lock_irq(cmd->device->host->host_lock);
189 	wd33c93_host_reset(cmd);
190 	spin_unlock_irq(cmd->device->host->host_lock);
191 
192 	return SUCCESS;
193 }
194 
195 /*
196  * Kludge alert - the SCSI code calls the abort and reset method with int
197  * arguments not with pointers.  So this is going to blow up beautyfully
198  * on 64-bit systems with memory outside the compat address spaces.
199  */
200 static struct scsi_host_template sgiwd93_template = {
201 	.module			= THIS_MODULE,
202 	.proc_name		= "SGIWD93",
203 	.name			= "SGI WD93",
204 	.queuecommand		= wd33c93_queuecommand,
205 	.eh_abort_handler	= wd33c93_abort,
206 	.eh_bus_reset_handler	= sgiwd93_bus_reset,
207 	.eh_host_reset_handler	= wd33c93_host_reset,
208 	.can_queue		= 16,
209 	.this_id		= 7,
210 	.sg_tablesize		= SG_ALL,
211 	.cmd_per_lun		= 8,
212 	.use_clustering		= DISABLE_CLUSTERING,
213 };
214 
215 static int __init sgiwd93_probe(struct platform_device *pdev)
216 {
217 	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
218 	unsigned char *wdregs = pd->wdregs;
219 	struct hpc3_scsiregs *hregs = pd->hregs;
220 	struct ip22_hostdata *hdata;
221 	struct Scsi_Host *host;
222 	wd33c93_regs regs;
223 	unsigned int unit = pd->unit;
224 	unsigned int irq = pd->irq;
225 	int err;
226 
227 	host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
228 	if (!host) {
229 		err = -ENOMEM;
230 		goto out;
231 	}
232 
233 	host->base = (unsigned long) hregs;
234 	host->irq = irq;
235 
236 	hdata = host_to_hostdata(host);
237 	hdata->hd.cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE,
238 	                                   &hdata->hd.dma, GFP_KERNEL);
239 	if (!hdata->hd.cpu) {
240 		printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
241 		       "host %d buffer.\n", unit);
242 		err = -ENOMEM;
243 		goto out_put;
244 	}
245 
246 	init_hpc_chain(&hdata->hd);
247 
248 	regs.SASR = wdregs + 3;
249 	regs.SCMD = wdregs + 7;
250 
251 	wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
252 
253 	if (hdata->wh.no_sync == 0xff)
254 		hdata->wh.no_sync = 0;
255 
256 	err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
257 	if (err) {
258 		printk(KERN_WARNING "sgiwd93: Could not register irq %d "
259 		       "for host %d.\n", irq, unit);
260 		goto out_free;
261 	}
262 
263 	platform_set_drvdata(pdev, host);
264 
265 	err = scsi_add_host(host, NULL);
266 	if (err)
267 		goto out_irq;
268 
269 	scsi_scan_host(host);
270 
271 	return 0;
272 
273 out_irq:
274 	free_irq(irq, host);
275 out_free:
276 	dma_free_coherent(NULL, PAGE_SIZE, hdata->hd.cpu, hdata->hd.dma);
277 out_put:
278 	scsi_host_put(host);
279 out:
280 
281 	return err;
282 }
283 
284 static void __exit sgiwd93_remove(struct platform_device *pdev)
285 {
286 	struct Scsi_Host *host = platform_get_drvdata(pdev);
287 	struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
288 	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
289 
290 	scsi_remove_host(host);
291 	free_irq(pd->irq, host);
292 	dma_free_coherent(&pdev->dev, PAGE_SIZE, hdata->hd.cpu, hdata->hd.dma);
293 	scsi_host_put(host);
294 }
295 
296 static struct platform_driver sgiwd93_driver = {
297 	.probe  = sgiwd93_probe,
298 	.remove = __devexit_p(sgiwd93_remove),
299 	.driver = {
300 		.name   = "sgiwd93"
301 	}
302 };
303 
304 static int __init sgiwd93_module_init(void)
305 {
306 	return platform_driver_register(&sgiwd93_driver);
307 }
308 
309 static void __exit sgiwd93_module_exit(void)
310 {
311 	return platform_driver_unregister(&sgiwd93_driver);
312 }
313 
314 module_init(sgiwd93_module_init);
315 module_exit(sgiwd93_module_exit);
316 
317 MODULE_DESCRIPTION("SGI WD33C93 driver");
318 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
319 MODULE_LICENSE("GPL");
320