tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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#include <linux/io.h>
16
17#include <asm/sun3x.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 int sun3x_esp_irq_pending(struct esp *esp)
64{
65 if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
66 return 1;
67 return 0;
68}
69
70static void sun3x_esp_reset_dma(struct esp *esp)
71{
72 u32 val;
73
74 val = dma_read32(DMA_CSR);
75 dma_write32(val | DMA_RST_SCSI, DMA_CSR);
76 dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
77
78 /* Enable interrupts. */
79 val = dma_read32(DMA_CSR);
80 dma_write32(val | DMA_INT_ENAB, DMA_CSR);
81}
82
83static void sun3x_esp_dma_drain(struct esp *esp)
84{
85 u32 csr;
86 int lim;
87
88 csr = dma_read32(DMA_CSR);
89 if (!(csr & DMA_FIFO_ISDRAIN))
90 return;
91
92 dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
93
94 lim = 1000;
95 while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
96 if (--lim == 0) {
97 printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
98 esp->host->unique_id);
99 break;
100 }
101 udelay(1);
102 }
103}
104
105static void sun3x_esp_dma_invalidate(struct esp *esp)
106{
107 u32 val;
108 int lim;
109
110 lim = 1000;
111 while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
112 if (--lim == 0) {
113 printk(KERN_ALERT PFX "esp%d: DMA will not "
114 "invalidate!\n", esp->host->unique_id);
115 break;
116 }
117 udelay(1);
118 }
119
120 val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
121 val |= DMA_FIFO_INV;
122 dma_write32(val, DMA_CSR);
123 val &= ~DMA_FIFO_INV;
124 dma_write32(val, DMA_CSR);
125}
126
127static void sun3x_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
128 u32 dma_count, int write, u8 cmd)
129{
130 u32 csr;
131
132 BUG_ON(!(cmd & ESP_CMD_DMA));
133
134 sun3x_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
135 sun3x_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
136 csr = dma_read32(DMA_CSR);
137 csr |= DMA_ENABLE;
138 if (write)
139 csr |= DMA_ST_WRITE;
140 else
141 csr &= ~DMA_ST_WRITE;
142 dma_write32(csr, DMA_CSR);
143 dma_write32(addr, DMA_ADDR);
144
145 scsi_esp_cmd(esp, cmd);
146}
147
148static int sun3x_esp_dma_error(struct esp *esp)
149{
150 u32 csr = dma_read32(DMA_CSR);
151
152 if (csr & DMA_HNDL_ERROR)
153 return 1;
154
155 return 0;
156}
157
158static const struct esp_driver_ops sun3x_esp_ops = {
159 .esp_write8 = sun3x_esp_write8,
160 .esp_read8 = sun3x_esp_read8,
161 .irq_pending = sun3x_esp_irq_pending,
162 .reset_dma = sun3x_esp_reset_dma,
163 .dma_drain = sun3x_esp_dma_drain,
164 .dma_invalidate = sun3x_esp_dma_invalidate,
165 .send_dma_cmd = sun3x_esp_send_dma_cmd,
166 .dma_error = sun3x_esp_dma_error,
167};
168
169static int esp_sun3x_probe(struct platform_device *dev)
170{
171 struct scsi_host_template *tpnt = &scsi_esp_template;
172 struct Scsi_Host *host;
173 struct esp *esp;
174 struct resource *res;
175 int err = -ENOMEM;
176
177 host = scsi_host_alloc(tpnt, sizeof(struct esp));
178 if (!host)
179 goto fail;
180
181 host->max_id = 8;
182 esp = shost_priv(host);
183
184 esp->host = host;
185 esp->dev = &dev->dev;
186 esp->ops = &sun3x_esp_ops;
187
188 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
189 if (!res || !res->start)
190 goto fail_unlink;
191
192 esp->regs = ioremap_nocache(res->start, 0x20);
193 if (!esp->regs)
194 goto fail_unmap_regs;
195
196 res = platform_get_resource(dev, IORESOURCE_MEM, 1);
197 if (!res || !res->start)
198 goto fail_unmap_regs;
199
200 esp->dma_regs = ioremap_nocache(res->start, 0x10);
201
202 esp->command_block = dma_alloc_coherent(esp->dev, 16,
203 &esp->command_block_dma,
204 GFP_KERNEL);
205 if (!esp->command_block)
206 goto fail_unmap_regs_dma;
207
208 host->irq = platform_get_irq(dev, 0);
209 err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED,
210 "SUN3X ESP", esp);
211 if (err < 0)
212 goto fail_unmap_command_block;
213
214 esp->scsi_id = 7;
215 esp->host->this_id = esp->scsi_id;
216 esp->scsi_id_mask = (1 << esp->scsi_id);
217 esp->cfreq = 20000000;
218
219 dev_set_drvdata(&dev->dev, esp);
220
221 err = scsi_esp_register(esp);
222 if (err)
223 goto fail_free_irq;
224
225 return 0;
226
227fail_free_irq:
228 free_irq(host->irq, esp);
229fail_unmap_command_block:
230 dma_free_coherent(esp->dev, 16,
231 esp->command_block,
232 esp->command_block_dma);
233fail_unmap_regs_dma:
234 iounmap(esp->dma_regs);
235fail_unmap_regs:
236 iounmap(esp->regs);
237fail_unlink:
238 scsi_host_put(host);
239fail:
240 return err;
241}
242
243static int esp_sun3x_remove(struct platform_device *dev)
244{
245 struct esp *esp = dev_get_drvdata(&dev->dev);
246 unsigned int irq = esp->host->irq;
247 u32 val;
248
249 scsi_esp_unregister(esp);
250
251 /* Disable interrupts. */
252 val = dma_read32(DMA_CSR);
253 dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
254
255 free_irq(irq, esp);
256 dma_free_coherent(esp->dev, 16,
257 esp->command_block,
258 esp->command_block_dma);
259
260 scsi_host_put(esp->host);
261
262 return 0;
263}
264
265static struct platform_driver esp_sun3x_driver = {
266 .probe = esp_sun3x_probe,
267 .remove = esp_sun3x_remove,
268 .driver = {
269 .name = "sun3x_esp",
270 },
271};
272
273static int __init sun3x_esp_init(void)
274{
275 return platform_driver_register(&esp_sun3x_driver);
276}
277
278static void __exit sun3x_esp_exit(void)
279{
280 platform_driver_unregister(&esp_sun3x_driver);
281}
282
283MODULE_DESCRIPTION("Sun3x ESP SCSI driver");
284MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)");
285MODULE_LICENSE("GPL");
286MODULE_VERSION(DRV_VERSION);
287
288module_init(sun3x_esp_init);
289module_exit(sun3x_esp_exit);
290MODULE_ALIAS("platform:sun3x_esp");