1/* sun3x_esp.c: ESP front-end for Sun3x systems.
2 *
3 * Copyright (C) 2007,2008 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
4 */
5
6#include <linux/kernel.h>
7#include <linux/gfp.h>
8#include <linux/types.h>
9#include <linux/delay.h>
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/platform_device.h>
13#include <linux/dma-mapping.h>
14#include <linux/interrupt.h>
15
16#include <asm/sun3x.h>
17#include <asm/io.h>
18#include <asm/dma.h>
19#include <asm/dvma.h>
20
21/* DMA controller reg offsets */
22#define DMA_CSR		0x00UL	/* rw  DMA control/status register    0x00   */
23#define DMA_ADDR        0x04UL	/* rw  DMA transfer address register  0x04   */
24#define DMA_COUNT       0x08UL	/* rw  DMA transfer count register    0x08   */
25#define DMA_TEST        0x0cUL	/* rw  DMA test/debug register        0x0c   */
26
27#include <scsi/scsi_host.h>
28
29#include "esp_scsi.h"
30
31#define DRV_MODULE_NAME		"sun3x_esp"
32#define PFX DRV_MODULE_NAME	": "
33#define DRV_VERSION		"1.000"
34#define DRV_MODULE_RELDATE	"Nov 1, 2007"
35
36/*
37 * m68k always assumes readl/writel operate on little endian
38 * mmio space; this is wrong at least for Sun3x, so we
39 * need to workaround this until a proper way is found
40 */
41#if 0
42#define dma_read32(REG) \
43	readl(esp->dma_regs + (REG))
44#define dma_write32(VAL, REG) \
45	writel((VAL), esp->dma_regs + (REG))
46#else
47#define dma_read32(REG) \
48	*(volatile u32 *)(esp->dma_regs + (REG))
49#define dma_write32(VAL, REG) \
50	do { *(volatile u32 *)(esp->dma_regs + (REG)) = (VAL); } while (0)
51#endif
52
53static void sun3x_esp_write8(struct esp *esp, u8 val, unsigned long reg)
54{
55	writeb(val, esp->regs + (reg * 4UL));
56}
57
58static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg)
59{
60	return readb(esp->regs + (reg * 4UL));
61}
62
63static dma_addr_t sun3x_esp_map_single(struct esp *esp, void *buf,
64				      size_t sz, int dir)
65{
66	return dma_map_single(esp->dev, buf, sz, dir);
67}
68
69static int sun3x_esp_map_sg(struct esp *esp, struct scatterlist *sg,
70				  int num_sg, int dir)
71{
72	return dma_map_sg(esp->dev, sg, num_sg, dir);
73}
74
75static void sun3x_esp_unmap_single(struct esp *esp, dma_addr_t addr,
76				  size_t sz, int dir)
77{
78	dma_unmap_single(esp->dev, addr, sz, dir);
79}
80
81static void sun3x_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
82			      int num_sg, int dir)
83{
84	dma_unmap_sg(esp->dev, sg, num_sg, dir);
85}
86
87static int sun3x_esp_irq_pending(struct esp *esp)
88{
89	if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
90		return 1;
91	return 0;
92}
93
94static void sun3x_esp_reset_dma(struct esp *esp)
95{
96	u32 val;
97
98	val = dma_read32(DMA_CSR);
99	dma_write32(val | DMA_RST_SCSI, DMA_CSR);
100	dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
101
102	/* Enable interrupts.  */
103	val = dma_read32(DMA_CSR);
104	dma_write32(val | DMA_INT_ENAB, DMA_CSR);
105}
106
107static void sun3x_esp_dma_drain(struct esp *esp)
108{
109	u32 csr;
110	int lim;
111
112	csr = dma_read32(DMA_CSR);
113	if (!(csr & DMA_FIFO_ISDRAIN))
114		return;
115
116	dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
117
118	lim = 1000;
119	while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
120		if (--lim == 0) {
121			printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
122			       esp->host->unique_id);
123			break;
124		}
125		udelay(1);
126	}
127}
128
129static void sun3x_esp_dma_invalidate(struct esp *esp)
130{
131	u32 val;
132	int lim;
133
134	lim = 1000;
135	while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
136		if (--lim == 0) {
137			printk(KERN_ALERT PFX "esp%d: DMA will not "
138			       "invalidate!\n", esp->host->unique_id);
139			break;
140		}
141		udelay(1);
142	}
143
144	val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
145	val |= DMA_FIFO_INV;
146	dma_write32(val, DMA_CSR);
147	val &= ~DMA_FIFO_INV;
148	dma_write32(val, DMA_CSR);
149}
150
151static void sun3x_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
152				  u32 dma_count, int write, u8 cmd)
153{
154	u32 csr;
155
156	BUG_ON(!(cmd & ESP_CMD_DMA));
157
158	sun3x_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
159	sun3x_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
160	csr = dma_read32(DMA_CSR);
161	csr |= DMA_ENABLE;
162	if (write)
163		csr |= DMA_ST_WRITE;
164	else
165		csr &= ~DMA_ST_WRITE;
166	dma_write32(csr, DMA_CSR);
167	dma_write32(addr, DMA_ADDR);
168
169	scsi_esp_cmd(esp, cmd);
170}
171
172static int sun3x_esp_dma_error(struct esp *esp)
173{
174	u32 csr = dma_read32(DMA_CSR);
175
176	if (csr & DMA_HNDL_ERROR)
177		return 1;
178
179	return 0;
180}
181
182static const struct esp_driver_ops sun3x_esp_ops = {
183	.esp_write8	=	sun3x_esp_write8,
184	.esp_read8	=	sun3x_esp_read8,
185	.map_single	=	sun3x_esp_map_single,
186	.map_sg		=	sun3x_esp_map_sg,
187	.unmap_single	=	sun3x_esp_unmap_single,
188	.unmap_sg	=	sun3x_esp_unmap_sg,
189	.irq_pending	=	sun3x_esp_irq_pending,
190	.reset_dma	=	sun3x_esp_reset_dma,
191	.dma_drain	=	sun3x_esp_dma_drain,
192	.dma_invalidate	=	sun3x_esp_dma_invalidate,
193	.send_dma_cmd	=	sun3x_esp_send_dma_cmd,
194	.dma_error	=	sun3x_esp_dma_error,
195};
196
197static int __devinit esp_sun3x_probe(struct platform_device *dev)
198{
199	struct scsi_host_template *tpnt = &scsi_esp_template;
200	struct Scsi_Host *host;
201	struct esp *esp;
202	struct resource *res;
203	int err = -ENOMEM;
204
205	host = scsi_host_alloc(tpnt, sizeof(struct esp));
206	if (!host)
207		goto fail;
208
209	host->max_id = 8;
210	esp = shost_priv(host);
211
212	esp->host = host;
213	esp->dev = dev;
214	esp->ops = &sun3x_esp_ops;
215
216	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
217	if (!res || !res->start)
218		goto fail_unlink;
219
220	esp->regs = ioremap_nocache(res->start, 0x20);
221	if (!esp->regs)
222		goto fail_unmap_regs;
223
224	res = platform_get_resource(dev, IORESOURCE_MEM, 1);
225	if (!res || !res->start)
226		goto fail_unmap_regs;
227
228	esp->dma_regs = ioremap_nocache(res->start, 0x10);
229
230	esp->command_block = dma_alloc_coherent(esp->dev, 16,
231						&esp->command_block_dma,
232						GFP_KERNEL);
233	if (!esp->command_block)
234		goto fail_unmap_regs_dma;
235
236	host->irq = platform_get_irq(dev, 0);
237	err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED,
238			  "SUN3X ESP", esp);
239	if (err < 0)
240		goto fail_unmap_command_block;
241
242	esp->scsi_id = 7;
243	esp->host->this_id = esp->scsi_id;
244	esp->scsi_id_mask = (1 << esp->scsi_id);
245	esp->cfreq = 20000000;
246
247	dev_set_drvdata(&dev->dev, esp);
248
249	err = scsi_esp_register(esp, &dev->dev);
250	if (err)
251		goto fail_free_irq;
252
253	return 0;
254
255fail_free_irq:
256	free_irq(host->irq, esp);
257fail_unmap_command_block:
258	dma_free_coherent(esp->dev, 16,
259			  esp->command_block,
260			  esp->command_block_dma);
261fail_unmap_regs_dma:
262	iounmap(esp->dma_regs);
263fail_unmap_regs:
264	iounmap(esp->regs);
265fail_unlink:
266	scsi_host_put(host);
267fail:
268	return err;
269}
270
271static int __devexit esp_sun3x_remove(struct platform_device *dev)
272{
273	struct esp *esp = dev_get_drvdata(&dev->dev);
274	unsigned int irq = esp->host->irq;
275	u32 val;
276
277	scsi_esp_unregister(esp);
278
279	/* Disable interrupts.  */
280	val = dma_read32(DMA_CSR);
281	dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
282
283	free_irq(irq, esp);
284	dma_free_coherent(esp->dev, 16,
285			  esp->command_block,
286			  esp->command_block_dma);
287
288	scsi_host_put(esp->host);
289
290	return 0;
291}
292
293static struct platform_driver esp_sun3x_driver = {
294	.probe          = esp_sun3x_probe,
295	.remove         = __devexit_p(esp_sun3x_remove),
296	.driver = {
297		.name   = "sun3x_esp",
298		.owner	= THIS_MODULE,
299	},
300};
301
302static int __init sun3x_esp_init(void)
303{
304	return platform_driver_register(&esp_sun3x_driver);
305}
306
307static void __exit sun3x_esp_exit(void)
308{
309	platform_driver_unregister(&esp_sun3x_driver);
310}
311
312MODULE_DESCRIPTION("Sun3x ESP SCSI driver");
313MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)");
314MODULE_LICENSE("GPL");
315MODULE_VERSION(DRV_VERSION);
316
317module_init(sun3x_esp_init);
318module_exit(sun3x_esp_exit);
319MODULE_ALIAS("platform:sun3x_esp");
320