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
38struct 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
47struct 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
57static 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
69static inline
70void 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
108static 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
142static 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
173void 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}
181EXPORT_SYMBOL_GPL(sgiwd93_reset);
182
183static 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 */
207static const 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
222static 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
282out_irq:
283	free_irq(irq, host);
284out_free:
285	dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
286			DMA_TO_DEVICE);
287out_put:
288	scsi_host_put(host);
289out:
290
291	return err;
292}
293
294static void 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}
306
307static struct platform_driver sgiwd93_driver = {
308	.probe  = sgiwd93_probe,
309	.remove_new = sgiwd93_remove,
310	.driver = {
311		.name   = "sgiwd93",
312	}
313};
314
315static int __init sgiwd93_module_init(void)
316{
317	return platform_driver_register(&sgiwd93_driver);
318}
319
320static void __exit sgiwd93_module_exit(void)
321{
322	return platform_driver_unregister(&sgiwd93_driver);
323}
324
325module_init(sgiwd93_module_init);
326module_exit(sgiwd93_module_exit);
327
328MODULE_DESCRIPTION("SGI WD33C93 driver");
329MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
330MODULE_LICENSE("GPL");
331MODULE_ALIAS("platform:sgiwd93");
332