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
sun3x_esp_write8(struct esp * esp,u8 val,unsigned long reg)54 static void sun3x_esp_write8(struct esp *esp, u8 val, unsigned long reg)
55 {
56 writeb(val, esp->regs + (reg * 4UL));
57 }
58
sun3x_esp_read8(struct esp * esp,unsigned long reg)59 static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg)
60 {
61 return readb(esp->regs + (reg * 4UL));
62 }
63
sun3x_esp_irq_pending(struct esp * esp)64 static 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
sun3x_esp_reset_dma(struct esp * esp)71 static 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
sun3x_esp_dma_drain(struct esp * esp)84 static 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
sun3x_esp_dma_invalidate(struct esp * esp)106 static 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
sun3x_esp_send_dma_cmd(struct esp * esp,u32 addr,u32 esp_count,u32 dma_count,int write,u8 cmd)128 static 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, (esp_count >> 0) & 0xff, ESP_TCLOW);
136 sun3x_esp_write8(esp, (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
sun3x_esp_dma_error(struct esp * esp)149 static 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
159 static 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
esp_sun3x_probe(struct platform_device * dev)170 static int esp_sun3x_probe(struct platform_device *dev)
171 {
172 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(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(res->start, 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(res->start, 0x10);
202
203 esp->command_block = dma_alloc_coherent(esp->dev, 16,
204 &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(host->irq, scsi_esp_intr, IRQF_SHARED,
213 "SUN3X ESP", 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, esp);
223
224 err = scsi_esp_register(esp);
225 if (err)
226 goto fail_free_irq;
227
228 return 0;
229
230 fail_free_irq:
231 free_irq(host->irq, esp);
232 fail_unmap_command_block:
233 dma_free_coherent(esp->dev, 16,
234 esp->command_block,
235 esp->command_block_dma);
236 fail_unmap_regs_dma:
237 iounmap(esp->dma_regs);
238 fail_unmap_regs:
239 iounmap(esp->regs);
240 fail_unlink:
241 scsi_host_put(host);
242 fail:
243 return err;
244 }
245
esp_sun3x_remove(struct platform_device * dev)246 static int esp_sun3x_remove(struct platform_device *dev)
247 {
248 struct esp *esp = dev_get_drvdata(&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(esp->dev, 16,
260 esp->command_block,
261 esp->command_block_dma);
262
263 scsi_host_put(esp->host);
264
265 return 0;
266 }
267
268 static struct platform_driver esp_sun3x_driver = {
269 .probe = esp_sun3x_probe,
270 .remove = esp_sun3x_remove,
271 .driver = {
272 .name = "sun3x_esp",
273 },
274 };
275 module_platform_driver(esp_sun3x_driver);
276
277 MODULE_DESCRIPTION("Sun3x ESP SCSI driver");
278 MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)");
279 MODULE_LICENSE("GPL");
280 MODULE_VERSION(DRV_VERSION);
281 MODULE_ALIAS("platform:sun3x_esp");
282