1 /*
2 * Generic PXA PATA driver
3 *
4 * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2, or (at your option)
9 * any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; see the file COPYING. If not, write to
18 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/blkdev.h>
25 #include <linux/ata.h>
26 #include <linux/libata.h>
27 #include <linux/platform_device.h>
28 #include <linux/gpio.h>
29 #include <linux/slab.h>
30 #include <linux/completion.h>
31
32 #include <scsi/scsi_host.h>
33
34 #include <mach/pxa2xx-regs.h>
35 #include <mach/pata_pxa.h>
36 #include <mach/dma.h>
37
38 #define DRV_NAME "pata_pxa"
39 #define DRV_VERSION "0.1"
40
41 struct pata_pxa_data {
42 uint32_t dma_channel;
43 struct pxa_dma_desc *dma_desc;
44 dma_addr_t dma_desc_addr;
45 uint32_t dma_desc_id;
46
47 /* DMA IO physical address */
48 uint32_t dma_io_addr;
49 /* PXA DREQ<0:2> pin selector */
50 uint32_t dma_dreq;
51 /* DMA DCSR register value */
52 uint32_t dma_dcsr;
53
54 struct completion dma_done;
55 };
56
57 /*
58 * Setup the DMA descriptors. The size is transfer capped at 4k per descriptor,
59 * if the transfer is longer, it is split into multiple chained descriptors.
60 */
pxa_load_dmac(struct scatterlist * sg,struct ata_queued_cmd * qc)61 static void pxa_load_dmac(struct scatterlist *sg, struct ata_queued_cmd *qc)
62 {
63 struct pata_pxa_data *pd = qc->ap->private_data;
64
65 uint32_t cpu_len, seg_len;
66 dma_addr_t cpu_addr;
67
68 cpu_addr = sg_dma_address(sg);
69 cpu_len = sg_dma_len(sg);
70
71 do {
72 seg_len = (cpu_len > 0x1000) ? 0x1000 : cpu_len;
73
74 pd->dma_desc[pd->dma_desc_id].ddadr = pd->dma_desc_addr +
75 ((pd->dma_desc_id + 1) * sizeof(struct pxa_dma_desc));
76
77 pd->dma_desc[pd->dma_desc_id].dcmd = DCMD_BURST32 |
78 DCMD_WIDTH2 | (DCMD_LENGTH & seg_len);
79
80 if (qc->tf.flags & ATA_TFLAG_WRITE) {
81 pd->dma_desc[pd->dma_desc_id].dsadr = cpu_addr;
82 pd->dma_desc[pd->dma_desc_id].dtadr = pd->dma_io_addr;
83 pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCSRCADDR |
84 DCMD_FLOWTRG;
85 } else {
86 pd->dma_desc[pd->dma_desc_id].dsadr = pd->dma_io_addr;
87 pd->dma_desc[pd->dma_desc_id].dtadr = cpu_addr;
88 pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCTRGADDR |
89 DCMD_FLOWSRC;
90 }
91
92 cpu_len -= seg_len;
93 cpu_addr += seg_len;
94 pd->dma_desc_id++;
95
96 } while (cpu_len);
97
98 /* Should not happen */
99 if (seg_len & 0x1f)
100 DALGN |= (1 << pd->dma_dreq);
101 }
102
103 /*
104 * Prepare taskfile for submission.
105 */
pxa_qc_prep(struct ata_queued_cmd * qc)106 static void pxa_qc_prep(struct ata_queued_cmd *qc)
107 {
108 struct pata_pxa_data *pd = qc->ap->private_data;
109 int si = 0;
110 struct scatterlist *sg;
111
112 if (!(qc->flags & ATA_QCFLAG_DMAMAP))
113 return;
114
115 pd->dma_desc_id = 0;
116
117 DCSR(pd->dma_channel) = 0;
118 DALGN &= ~(1 << pd->dma_dreq);
119
120 for_each_sg(qc->sg, sg, qc->n_elem, si)
121 pxa_load_dmac(sg, qc);
122
123 pd->dma_desc[pd->dma_desc_id - 1].ddadr = DDADR_STOP;
124
125 /* Fire IRQ only at the end of last block */
126 pd->dma_desc[pd->dma_desc_id - 1].dcmd |= DCMD_ENDIRQEN;
127
128 DDADR(pd->dma_channel) = pd->dma_desc_addr;
129 DRCMR(pd->dma_dreq) = DRCMR_MAPVLD | pd->dma_channel;
130
131 }
132
133 /*
134 * Configure the DMA controller, load the DMA descriptors, but don't start the
135 * DMA controller yet. Only issue the ATA command.
136 */
pxa_bmdma_setup(struct ata_queued_cmd * qc)137 static void pxa_bmdma_setup(struct ata_queued_cmd *qc)
138 {
139 qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
140 }
141
142 /*
143 * Execute the DMA transfer.
144 */
pxa_bmdma_start(struct ata_queued_cmd * qc)145 static void pxa_bmdma_start(struct ata_queued_cmd *qc)
146 {
147 struct pata_pxa_data *pd = qc->ap->private_data;
148 init_completion(&pd->dma_done);
149 DCSR(pd->dma_channel) = DCSR_RUN;
150 }
151
152 /*
153 * Wait until the DMA transfer completes, then stop the DMA controller.
154 */
pxa_bmdma_stop(struct ata_queued_cmd * qc)155 static void pxa_bmdma_stop(struct ata_queued_cmd *qc)
156 {
157 struct pata_pxa_data *pd = qc->ap->private_data;
158
159 if ((DCSR(pd->dma_channel) & DCSR_RUN) &&
160 wait_for_completion_timeout(&pd->dma_done, HZ))
161 dev_err(qc->ap->dev, "Timeout waiting for DMA completion!");
162
163 DCSR(pd->dma_channel) = 0;
164 }
165
166 /*
167 * Read DMA status. The bmdma_stop() will take care of properly finishing the
168 * DMA transfer so we always have DMA-complete interrupt here.
169 */
pxa_bmdma_status(struct ata_port * ap)170 static unsigned char pxa_bmdma_status(struct ata_port *ap)
171 {
172 struct pata_pxa_data *pd = ap->private_data;
173 unsigned char ret = ATA_DMA_INTR;
174
175 if (pd->dma_dcsr & DCSR_BUSERR)
176 ret |= ATA_DMA_ERR;
177
178 return ret;
179 }
180
181 /*
182 * No IRQ register present so we do nothing.
183 */
pxa_irq_clear(struct ata_port * ap)184 static void pxa_irq_clear(struct ata_port *ap)
185 {
186 }
187
188 /*
189 * Check for ATAPI DMA. ATAPI DMA is unsupported by this driver. It's still
190 * unclear why ATAPI has DMA issues.
191 */
pxa_check_atapi_dma(struct ata_queued_cmd * qc)192 static int pxa_check_atapi_dma(struct ata_queued_cmd *qc)
193 {
194 return -EOPNOTSUPP;
195 }
196
197 static struct scsi_host_template pxa_ata_sht = {
198 ATA_BMDMA_SHT(DRV_NAME),
199 };
200
201 static struct ata_port_operations pxa_ata_port_ops = {
202 .inherits = &ata_bmdma_port_ops,
203 .cable_detect = ata_cable_40wire,
204
205 .bmdma_setup = pxa_bmdma_setup,
206 .bmdma_start = pxa_bmdma_start,
207 .bmdma_stop = pxa_bmdma_stop,
208 .bmdma_status = pxa_bmdma_status,
209
210 .check_atapi_dma = pxa_check_atapi_dma,
211
212 .sff_irq_clear = pxa_irq_clear,
213
214 .qc_prep = pxa_qc_prep,
215 };
216
217 /*
218 * DMA interrupt handler.
219 */
pxa_ata_dma_irq(int dma,void * port)220 static void pxa_ata_dma_irq(int dma, void *port)
221 {
222 struct ata_port *ap = port;
223 struct pata_pxa_data *pd = ap->private_data;
224
225 pd->dma_dcsr = DCSR(dma);
226 DCSR(dma) = pd->dma_dcsr;
227
228 if (pd->dma_dcsr & DCSR_STOPSTATE)
229 complete(&pd->dma_done);
230 }
231
pxa_ata_probe(struct platform_device * pdev)232 static int __devinit pxa_ata_probe(struct platform_device *pdev)
233 {
234 struct ata_host *host;
235 struct ata_port *ap;
236 struct pata_pxa_data *data;
237 struct resource *cmd_res;
238 struct resource *ctl_res;
239 struct resource *dma_res;
240 struct resource *irq_res;
241 struct pata_pxa_pdata *pdata = pdev->dev.platform_data;
242 int ret = 0;
243
244 /*
245 * Resource validation, three resources are needed:
246 * - CMD port base address
247 * - CTL port base address
248 * - DMA port base address
249 * - IRQ pin
250 */
251 if (pdev->num_resources != 4) {
252 dev_err(&pdev->dev, "invalid number of resources\n");
253 return -EINVAL;
254 }
255
256 /*
257 * CMD port base address
258 */
259 cmd_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
260 if (unlikely(cmd_res == NULL))
261 return -EINVAL;
262
263 /*
264 * CTL port base address
265 */
266 ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
267 if (unlikely(ctl_res == NULL))
268 return -EINVAL;
269
270 /*
271 * DMA port base address
272 */
273 dma_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
274 if (unlikely(dma_res == NULL))
275 return -EINVAL;
276
277 /*
278 * IRQ pin
279 */
280 irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
281 if (unlikely(irq_res == NULL))
282 return -EINVAL;
283
284 /*
285 * Allocate the host
286 */
287 host = ata_host_alloc(&pdev->dev, 1);
288 if (!host)
289 return -ENOMEM;
290
291 ap = host->ports[0];
292 ap->ops = &pxa_ata_port_ops;
293 ap->pio_mask = ATA_PIO4;
294 ap->mwdma_mask = ATA_MWDMA2;
295
296 ap->ioaddr.cmd_addr = devm_ioremap(&pdev->dev, cmd_res->start,
297 resource_size(cmd_res));
298 ap->ioaddr.ctl_addr = devm_ioremap(&pdev->dev, ctl_res->start,
299 resource_size(ctl_res));
300 ap->ioaddr.bmdma_addr = devm_ioremap(&pdev->dev, dma_res->start,
301 resource_size(dma_res));
302
303 /*
304 * Adjust register offsets
305 */
306 ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
307 ap->ioaddr.data_addr = ap->ioaddr.cmd_addr +
308 (ATA_REG_DATA << pdata->reg_shift);
309 ap->ioaddr.error_addr = ap->ioaddr.cmd_addr +
310 (ATA_REG_ERR << pdata->reg_shift);
311 ap->ioaddr.feature_addr = ap->ioaddr.cmd_addr +
312 (ATA_REG_FEATURE << pdata->reg_shift);
313 ap->ioaddr.nsect_addr = ap->ioaddr.cmd_addr +
314 (ATA_REG_NSECT << pdata->reg_shift);
315 ap->ioaddr.lbal_addr = ap->ioaddr.cmd_addr +
316 (ATA_REG_LBAL << pdata->reg_shift);
317 ap->ioaddr.lbam_addr = ap->ioaddr.cmd_addr +
318 (ATA_REG_LBAM << pdata->reg_shift);
319 ap->ioaddr.lbah_addr = ap->ioaddr.cmd_addr +
320 (ATA_REG_LBAH << pdata->reg_shift);
321 ap->ioaddr.device_addr = ap->ioaddr.cmd_addr +
322 (ATA_REG_DEVICE << pdata->reg_shift);
323 ap->ioaddr.status_addr = ap->ioaddr.cmd_addr +
324 (ATA_REG_STATUS << pdata->reg_shift);
325 ap->ioaddr.command_addr = ap->ioaddr.cmd_addr +
326 (ATA_REG_CMD << pdata->reg_shift);
327
328 /*
329 * Allocate and load driver's internal data structure
330 */
331 data = devm_kzalloc(&pdev->dev, sizeof(struct pata_pxa_data),
332 GFP_KERNEL);
333 if (!data)
334 return -ENOMEM;
335
336 ap->private_data = data;
337 data->dma_dreq = pdata->dma_dreq;
338 data->dma_io_addr = dma_res->start;
339
340 /*
341 * Allocate space for the DMA descriptors
342 */
343 data->dma_desc = dmam_alloc_coherent(&pdev->dev, PAGE_SIZE,
344 &data->dma_desc_addr, GFP_KERNEL);
345 if (!data->dma_desc)
346 return -EINVAL;
347
348 /*
349 * Request the DMA channel
350 */
351 data->dma_channel = pxa_request_dma(DRV_NAME, DMA_PRIO_LOW,
352 pxa_ata_dma_irq, ap);
353 if (data->dma_channel < 0)
354 return -EBUSY;
355
356 /*
357 * Stop and clear the DMA channel
358 */
359 DCSR(data->dma_channel) = 0;
360
361 /*
362 * Activate the ATA host
363 */
364 ret = ata_host_activate(host, irq_res->start, ata_sff_interrupt,
365 pdata->irq_flags, &pxa_ata_sht);
366 if (ret)
367 pxa_free_dma(data->dma_channel);
368
369 return ret;
370 }
371
pxa_ata_remove(struct platform_device * pdev)372 static int __devexit pxa_ata_remove(struct platform_device *pdev)
373 {
374 struct ata_host *host = dev_get_drvdata(&pdev->dev);
375 struct pata_pxa_data *data = host->ports[0]->private_data;
376
377 pxa_free_dma(data->dma_channel);
378
379 ata_host_detach(host);
380
381 return 0;
382 }
383
384 static struct platform_driver pxa_ata_driver = {
385 .probe = pxa_ata_probe,
386 .remove = __devexit_p(pxa_ata_remove),
387 .driver = {
388 .name = DRV_NAME,
389 .owner = THIS_MODULE,
390 },
391 };
392
pxa_ata_init(void)393 static int __init pxa_ata_init(void)
394 {
395 return platform_driver_register(&pxa_ata_driver);
396 }
397
pxa_ata_exit(void)398 static void __exit pxa_ata_exit(void)
399 {
400 platform_driver_unregister(&pxa_ata_driver);
401 }
402
403 module_init(pxa_ata_init);
404 module_exit(pxa_ata_exit);
405
406 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
407 MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU");
408 MODULE_LICENSE("GPL");
409 MODULE_VERSION(DRV_VERSION);
410 MODULE_ALIAS("platform:" DRV_NAME);
411