1// SPDX-License-Identifier: GPL-2.0-only
2/* sun3x_esp.c: ESP front-end for Sun3x systems.
3 *
4 * Copyright (C) 2007,2008 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
5 */
6
7#include <linux/kernel.h>
8#include <linux/gfp.h>
9#include <linux/types.h>
10#include <linux/delay.h>
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/platform_device.h>
14#include <linux/dma-mapping.h>
15#include <linux/interrupt.h>
16#include <linux/io.h>
17
18#include <asm/sun3x.h>
19#include <asm/dma.h>
20#include <asm/dvma.h>
21
22/* DMA controller reg offsets */
23#define DMA_CSR 0x00UL /* rw DMA control/status register 0x00 */
24#define DMA_ADDR 0x04UL /* rw DMA transfer address register 0x04 */
25#define DMA_COUNT 0x08UL /* rw DMA transfer count register 0x08 */
26#define DMA_TEST 0x0cUL /* rw DMA test/debug register 0x0c */
27
28#include <scsi/scsi_host.h>
29
30#include "esp_scsi.h"
31
32#define DRV_MODULE_NAME "sun3x_esp"
33#define PFX DRV_MODULE_NAME ": "
34#define DRV_VERSION "1.000"
35#define DRV_MODULE_RELDATE "Nov 1, 2007"
36
37/*
38 * m68k always assumes readl/writel operate on little endian
39 * mmio space; this is wrong at least for Sun3x, so we
40 * need to workaround this until a proper way is found
41 */
42#if 0
43#define dma_read32(REG) \
44 readl(esp->dma_regs + (REG))
45#define dma_write32(VAL, REG) \
46 writel((VAL), esp->dma_regs + (REG))
47#else
48#define dma_read32(REG) \
49 *(volatile u32 *)(esp->dma_regs + (REG))
50#define dma_write32(VAL, REG) \
51 do { *(volatile u32 *)(esp->dma_regs + (REG)) = (VAL); } while (0)
52#endif
53
54static void sun3x_esp_write8(struct esp *esp, u8 val, unsigned long reg)
55{
56 writeb(val, addr: esp->regs + (reg * 4UL));
57}
58
59static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg)
60{
61 return readb(addr: esp->regs + (reg * 4UL));
62}
63
64static int sun3x_esp_irq_pending(struct esp *esp)
65{
66 if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
67 return 1;
68 return 0;
69}
70
71static void sun3x_esp_reset_dma(struct esp *esp)
72{
73 u32 val;
74
75 val = dma_read32(DMA_CSR);
76 dma_write32(val | DMA_RST_SCSI, DMA_CSR);
77 dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
78
79 /* Enable interrupts. */
80 val = dma_read32(DMA_CSR);
81 dma_write32(val | DMA_INT_ENAB, DMA_CSR);
82}
83
84static void sun3x_esp_dma_drain(struct esp *esp)
85{
86 u32 csr;
87 int lim;
88
89 csr = dma_read32(DMA_CSR);
90 if (!(csr & DMA_FIFO_ISDRAIN))
91 return;
92
93 dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
94
95 lim = 1000;
96 while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
97 if (--lim == 0) {
98 printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
99 esp->host->unique_id);
100 break;
101 }
102 udelay(1);
103 }
104}
105
106static void sun3x_esp_dma_invalidate(struct esp *esp)
107{
108 u32 val;
109 int lim;
110
111 lim = 1000;
112 while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
113 if (--lim == 0) {
114 printk(KERN_ALERT PFX "esp%d: DMA will not "
115 "invalidate!\n", esp->host->unique_id);
116 break;
117 }
118 udelay(1);
119 }
120
121 val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
122 val |= DMA_FIFO_INV;
123 dma_write32(val, DMA_CSR);
124 val &= ~DMA_FIFO_INV;
125 dma_write32(val, DMA_CSR);
126}
127
128static void sun3x_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
129 u32 dma_count, int write, u8 cmd)
130{
131 u32 csr;
132
133 BUG_ON(!(cmd & ESP_CMD_DMA));
134
135 sun3x_esp_write8(esp, val: (esp_count >> 0) & 0xff, ESP_TCLOW);
136 sun3x_esp_write8(esp, val: (esp_count >> 8) & 0xff, ESP_TCMED);
137 csr = dma_read32(DMA_CSR);
138 csr |= DMA_ENABLE;
139 if (write)
140 csr |= DMA_ST_WRITE;
141 else
142 csr &= ~DMA_ST_WRITE;
143 dma_write32(csr, DMA_CSR);
144 dma_write32(addr, DMA_ADDR);
145
146 scsi_esp_cmd(esp, cmd);
147}
148
149static int sun3x_esp_dma_error(struct esp *esp)
150{
151 u32 csr = dma_read32(DMA_CSR);
152
153 if (csr & DMA_HNDL_ERROR)
154 return 1;
155
156 return 0;
157}
158
159static const struct esp_driver_ops sun3x_esp_ops = {
160 .esp_write8 = sun3x_esp_write8,
161 .esp_read8 = sun3x_esp_read8,
162 .irq_pending = sun3x_esp_irq_pending,
163 .reset_dma = sun3x_esp_reset_dma,
164 .dma_drain = sun3x_esp_dma_drain,
165 .dma_invalidate = sun3x_esp_dma_invalidate,
166 .send_dma_cmd = sun3x_esp_send_dma_cmd,
167 .dma_error = sun3x_esp_dma_error,
168};
169
170static int esp_sun3x_probe(struct platform_device *dev)
171{
172 const struct scsi_host_template *tpnt = &scsi_esp_template;
173 struct Scsi_Host *host;
174 struct esp *esp;
175 struct resource *res;
176 int err = -ENOMEM;
177
178 host = scsi_host_alloc(tpnt, sizeof(struct esp));
179 if (!host)
180 goto fail;
181
182 host->max_id = 8;
183 esp = shost_priv(shost: host);
184
185 esp->host = host;
186 esp->dev = &dev->dev;
187 esp->ops = &sun3x_esp_ops;
188
189 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
190 if (!res || !res->start)
191 goto fail_unlink;
192
193 esp->regs = ioremap(offset: res->start, size: 0x20);
194 if (!esp->regs)
195 goto fail_unmap_regs;
196
197 res = platform_get_resource(dev, IORESOURCE_MEM, 1);
198 if (!res || !res->start)
199 goto fail_unmap_regs;
200
201 esp->dma_regs = ioremap(offset: res->start, size: 0x10);
202
203 esp->command_block = dma_alloc_coherent(dev: esp->dev, size: 16,
204 dma_handle: &esp->command_block_dma,
205 GFP_KERNEL);
206 if (!esp->command_block)
207 goto fail_unmap_regs_dma;
208
209 host->irq = err = platform_get_irq(dev, 0);
210 if (err < 0)
211 goto fail_unmap_command_block;
212 err = request_irq(irq: host->irq, handler: scsi_esp_intr, IRQF_SHARED,
213 name: "SUN3X ESP", dev: esp);
214 if (err < 0)
215 goto fail_unmap_command_block;
216
217 esp->scsi_id = 7;
218 esp->host->this_id = esp->scsi_id;
219 esp->scsi_id_mask = (1 << esp->scsi_id);
220 esp->cfreq = 20000000;
221
222 dev_set_drvdata(dev: &dev->dev, data: esp);
223
224 err = scsi_esp_register(esp);
225 if (err)
226 goto fail_free_irq;
227
228 return 0;
229
230fail_free_irq:
231 free_irq(host->irq, esp);
232fail_unmap_command_block:
233 dma_free_coherent(dev: esp->dev, size: 16,
234 cpu_addr: esp->command_block,
235 dma_handle: esp->command_block_dma);
236fail_unmap_regs_dma:
237 iounmap(addr: esp->dma_regs);
238fail_unmap_regs:
239 iounmap(addr: esp->regs);
240fail_unlink:
241 scsi_host_put(t: host);
242fail:
243 return err;
244}
245
246static int esp_sun3x_remove(struct platform_device *dev)
247{
248 struct esp *esp = dev_get_drvdata(dev: &dev->dev);
249 unsigned int irq = esp->host->irq;
250 u32 val;
251
252 scsi_esp_unregister(esp);
253
254 /* Disable interrupts. */
255 val = dma_read32(DMA_CSR);
256 dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
257
258 free_irq(irq, esp);
259 dma_free_coherent(dev: esp->dev, size: 16,
260 cpu_addr: esp->command_block,
261 dma_handle: esp->command_block_dma);
262
263 scsi_host_put(t: esp->host);
264
265 return 0;
266}
267
268static struct platform_driver esp_sun3x_driver = {
269 .probe = esp_sun3x_probe,
270 .remove = esp_sun3x_remove,
271 .driver = {
272 .name = "sun3x_esp",
273 },
274};
275module_platform_driver(esp_sun3x_driver);
276
277MODULE_DESCRIPTION("Sun3x ESP SCSI driver");
278MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)");
279MODULE_LICENSE("GPL");
280MODULE_VERSION(DRV_VERSION);
281MODULE_ALIAS("platform:sun3x_esp");
282

source code of linux/drivers/scsi/sun3x_esp.c