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	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
44struct hpc_chunk {
45	struct hpc_dma_desc desc;
46	u32 _padding;	/* align to quadword boundary */
47};
48
49static 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
61static inline
62void 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
94static 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
128static 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
154void 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}
162EXPORT_SYMBOL_GPL(sgiwd93_reset);
163
164static inline void init_hpc_chain(struct hpc_data *hd)
165{
166	struct hpc_chunk *hcp = (struct hpc_chunk *) hd->cpu;
167	struct hpc_chunk *dma = (struct hpc_chunk *) hd->dma;
168	unsigned long start, end;
169
170	start = (unsigned long) hcp;
171	end = start + PAGE_SIZE;
172	while (start < end) {
173		hcp->desc.pnext = (u32) (dma + 1);
174		hcp->desc.cntinfo = HPCDMA_EOX;
175		hcp++; dma++;
176		start += sizeof(struct hpc_chunk);
177	};
178	hcp--;
179	hcp->desc.pnext = hd->dma;
180}
181
182static int sgiwd93_bus_reset(struct scsi_cmnd *cmd)
183{
184
185
186	spin_lock_irq(cmd->device->host->host_lock);
187	wd33c93_host_reset(cmd);
188	spin_unlock_irq(cmd->device->host->host_lock);
189
190	return SUCCESS;
191}
192
193/*
194 * Kludge alert - the SCSI code calls the abort and reset method with int
195 * arguments not with pointers.  So this is going to blow up beautyfully
196 * on 64-bit systems with memory outside the compat address spaces.
197 */
198static struct scsi_host_template sgiwd93_template = {
199	.module			= THIS_MODULE,
200	.proc_name		= "SGIWD93",
201	.name			= "SGI WD93",
202	.queuecommand		= wd33c93_queuecommand,
203	.eh_abort_handler	= wd33c93_abort,
204	.eh_bus_reset_handler	= sgiwd93_bus_reset,
205	.eh_host_reset_handler	= wd33c93_host_reset,
206	.can_queue		= 16,
207	.this_id		= 7,
208	.sg_tablesize		= SG_ALL,
209	.cmd_per_lun		= 8,
210	.use_clustering		= DISABLE_CLUSTERING,
211};
212
213static int __init sgiwd93_probe(struct platform_device *pdev)
214{
215	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
216	unsigned char *wdregs = pd->wdregs;
217	struct hpc3_scsiregs *hregs = pd->hregs;
218	struct ip22_hostdata *hdata;
219	struct Scsi_Host *host;
220	wd33c93_regs regs;
221	unsigned int unit = pd->unit;
222	unsigned int irq = pd->irq;
223	int err;
224
225	host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
226	if (!host) {
227		err = -ENOMEM;
228		goto out;
229	}
230
231	host->base = (unsigned long) hregs;
232	host->irq = irq;
233
234	hdata = host_to_hostdata(host);
235	hdata->hd.cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE,
236	                                   &hdata->hd.dma, GFP_KERNEL);
237	if (!hdata->hd.cpu) {
238		printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
239		       "host %d buffer.\n", unit);
240		err = -ENOMEM;
241		goto out_put;
242	}
243
244	init_hpc_chain(&hdata->hd);
245
246	regs.SASR = wdregs + 3;
247	regs.SCMD = wdregs + 7;
248
249	wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
250
251	if (hdata->wh.no_sync == 0xff)
252		hdata->wh.no_sync = 0;
253
254	err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
255	if (err) {
256		printk(KERN_WARNING "sgiwd93: Could not register irq %d "
257		       "for host %d.\n", irq, unit);
258		goto out_free;
259	}
260
261	platform_set_drvdata(pdev, host);
262
263	err = scsi_add_host(host, NULL);
264	if (err)
265		goto out_irq;
266
267	scsi_scan_host(host);
268
269	return 0;
270
271out_irq:
272	free_irq(irq, host);
273out_free:
274	dma_free_coherent(NULL, PAGE_SIZE, hdata->hd.cpu, hdata->hd.dma);
275out_put:
276	scsi_host_put(host);
277out:
278
279	return err;
280}
281
282static void __exit sgiwd93_remove(struct platform_device *pdev)
283{
284	struct Scsi_Host *host = platform_get_drvdata(pdev);
285	struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
286	struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
287
288	scsi_remove_host(host);
289	free_irq(pd->irq, host);
290	dma_free_coherent(&pdev->dev, PAGE_SIZE, hdata->hd.cpu, hdata->hd.dma);
291	scsi_host_put(host);
292}
293
294static struct platform_driver sgiwd93_driver = {
295	.probe  = sgiwd93_probe,
296	.remove = __devexit_p(sgiwd93_remove),
297	.driver = {
298		.name   = "sgiwd93"
299	}
300};
301
302static int __init sgiwd93_module_init(void)
303{
304	return platform_driver_register(&sgiwd93_driver);
305}
306
307static void __exit sgiwd93_module_exit(void)
308{
309	return platform_driver_unregister(&sgiwd93_driver);
310}
311
312module_init(sgiwd93_module_init);
313module_exit(sgiwd93_module_exit);
314
315MODULE_DESCRIPTION("SGI WD33C93 driver");
316MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
317MODULE_LICENSE("GPL");
318