1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic PXA PATA driver
4 *
5 * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/blkdev.h>
11#include <linux/ata.h>
12#include <linux/libata.h>
13#include <linux/platform_device.h>
14#include <linux/dmaengine.h>
15#include <linux/slab.h>
16#include <linux/completion.h>
17
18#include <scsi/scsi_host.h>
19
20#include <linux/platform_data/ata-pxa.h>
21
22#define DRV_NAME "pata_pxa"
23#define DRV_VERSION "0.1"
24
25struct pata_pxa_data {
26 struct dma_chan *dma_chan;
27 dma_cookie_t dma_cookie;
28 struct completion dma_done;
29};
30
31/*
32 * DMA interrupt handler.
33 */
34static void pxa_ata_dma_irq(void *d)
35{
36 struct pata_pxa_data *pd = d;
37 enum dma_status status;
38
39 status = dmaengine_tx_status(chan: pd->dma_chan, cookie: pd->dma_cookie, NULL);
40 if (status == DMA_ERROR || status == DMA_COMPLETE)
41 complete(&pd->dma_done);
42}
43
44/*
45 * Prepare taskfile for submission.
46 */
47static enum ata_completion_errors pxa_qc_prep(struct ata_queued_cmd *qc)
48{
49 struct pata_pxa_data *pd = qc->ap->private_data;
50 struct dma_async_tx_descriptor *tx;
51 enum dma_transfer_direction dir;
52
53 if (!(qc->flags & ATA_QCFLAG_DMAMAP))
54 return AC_ERR_OK;
55
56 dir = (qc->dma_dir == DMA_TO_DEVICE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM);
57 tx = dmaengine_prep_slave_sg(chan: pd->dma_chan, sgl: qc->sg, sg_len: qc->n_elem, dir,
58 flags: DMA_PREP_INTERRUPT);
59 if (!tx) {
60 ata_dev_err(qc->dev, "prep_slave_sg() failed\n");
61 return AC_ERR_OK;
62 }
63 tx->callback = pxa_ata_dma_irq;
64 tx->callback_param = pd;
65 pd->dma_cookie = dmaengine_submit(desc: tx);
66
67 return AC_ERR_OK;
68}
69
70/*
71 * Configure the DMA controller, load the DMA descriptors, but don't start the
72 * DMA controller yet. Only issue the ATA command.
73 */
74static void pxa_bmdma_setup(struct ata_queued_cmd *qc)
75{
76 qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
77}
78
79/*
80 * Execute the DMA transfer.
81 */
82static void pxa_bmdma_start(struct ata_queued_cmd *qc)
83{
84 struct pata_pxa_data *pd = qc->ap->private_data;
85 init_completion(x: &pd->dma_done);
86 dma_async_issue_pending(chan: pd->dma_chan);
87}
88
89/*
90 * Wait until the DMA transfer completes, then stop the DMA controller.
91 */
92static void pxa_bmdma_stop(struct ata_queued_cmd *qc)
93{
94 struct pata_pxa_data *pd = qc->ap->private_data;
95 enum dma_status status;
96
97 status = dmaengine_tx_status(chan: pd->dma_chan, cookie: pd->dma_cookie, NULL);
98 if (status != DMA_ERROR && status != DMA_COMPLETE &&
99 wait_for_completion_timeout(x: &pd->dma_done, HZ))
100 ata_dev_err(qc->dev, "Timeout waiting for DMA completion!");
101
102 dmaengine_terminate_all(chan: pd->dma_chan);
103}
104
105/*
106 * Read DMA status. The bmdma_stop() will take care of properly finishing the
107 * DMA transfer so we always have DMA-complete interrupt here.
108 */
109static unsigned char pxa_bmdma_status(struct ata_port *ap)
110{
111 struct pata_pxa_data *pd = ap->private_data;
112 unsigned char ret = ATA_DMA_INTR;
113 struct dma_tx_state state;
114 enum dma_status status;
115
116 status = dmaengine_tx_status(chan: pd->dma_chan, cookie: pd->dma_cookie, state: &state);
117 if (status != DMA_COMPLETE)
118 ret |= ATA_DMA_ERR;
119
120 return ret;
121}
122
123/*
124 * No IRQ register present so we do nothing.
125 */
126static void pxa_irq_clear(struct ata_port *ap)
127{
128}
129
130/*
131 * Check for ATAPI DMA. ATAPI DMA is unsupported by this driver. It's still
132 * unclear why ATAPI has DMA issues.
133 */
134static int pxa_check_atapi_dma(struct ata_queued_cmd *qc)
135{
136 return -EOPNOTSUPP;
137}
138
139static const struct scsi_host_template pxa_ata_sht = {
140 ATA_BMDMA_SHT(DRV_NAME),
141};
142
143static struct ata_port_operations pxa_ata_port_ops = {
144 .inherits = &ata_bmdma_port_ops,
145 .cable_detect = ata_cable_40wire,
146
147 .bmdma_setup = pxa_bmdma_setup,
148 .bmdma_start = pxa_bmdma_start,
149 .bmdma_stop = pxa_bmdma_stop,
150 .bmdma_status = pxa_bmdma_status,
151
152 .check_atapi_dma = pxa_check_atapi_dma,
153
154 .sff_irq_clear = pxa_irq_clear,
155
156 .qc_prep = pxa_qc_prep,
157};
158
159static int pxa_ata_probe(struct platform_device *pdev)
160{
161 struct ata_host *host;
162 struct ata_port *ap;
163 struct pata_pxa_data *data;
164 struct resource *cmd_res;
165 struct resource *ctl_res;
166 struct resource *dma_res;
167 struct pata_pxa_pdata *pdata = dev_get_platdata(dev: &pdev->dev);
168 struct dma_slave_config config;
169 int ret = 0;
170 int irq;
171
172 /*
173 * Resource validation, three resources are needed:
174 * - CMD port base address
175 * - CTL port base address
176 * - DMA port base address
177 * - IRQ pin
178 */
179 if (pdev->num_resources != 4) {
180 dev_err(&pdev->dev, "invalid number of resources\n");
181 return -EINVAL;
182 }
183
184 /*
185 * CMD port base address
186 */
187 cmd_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
188 if (unlikely(cmd_res == NULL))
189 return -EINVAL;
190
191 /*
192 * CTL port base address
193 */
194 ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
195 if (unlikely(ctl_res == NULL))
196 return -EINVAL;
197
198 /*
199 * DMA port base address
200 */
201 dma_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
202 if (unlikely(dma_res == NULL))
203 return -EINVAL;
204
205 /*
206 * IRQ pin
207 */
208 irq = platform_get_irq(pdev, 0);
209 if (irq < 0)
210 return irq;
211
212 /*
213 * Allocate the host
214 */
215 host = ata_host_alloc(dev: &pdev->dev, max_ports: 1);
216 if (!host)
217 return -ENOMEM;
218
219 ap = host->ports[0];
220 ap->ops = &pxa_ata_port_ops;
221 ap->pio_mask = ATA_PIO4;
222 ap->mwdma_mask = ATA_MWDMA2;
223
224 ap->ioaddr.cmd_addr = devm_ioremap(dev: &pdev->dev, offset: cmd_res->start,
225 size: resource_size(res: cmd_res));
226 ap->ioaddr.ctl_addr = devm_ioremap(dev: &pdev->dev, offset: ctl_res->start,
227 size: resource_size(res: ctl_res));
228 ap->ioaddr.bmdma_addr = devm_ioremap(dev: &pdev->dev, offset: dma_res->start,
229 size: resource_size(res: dma_res));
230
231 /*
232 * Adjust register offsets
233 */
234 ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
235 ap->ioaddr.data_addr = ap->ioaddr.cmd_addr +
236 (ATA_REG_DATA << pdata->reg_shift);
237 ap->ioaddr.error_addr = ap->ioaddr.cmd_addr +
238 (ATA_REG_ERR << pdata->reg_shift);
239 ap->ioaddr.feature_addr = ap->ioaddr.cmd_addr +
240 (ATA_REG_FEATURE << pdata->reg_shift);
241 ap->ioaddr.nsect_addr = ap->ioaddr.cmd_addr +
242 (ATA_REG_NSECT << pdata->reg_shift);
243 ap->ioaddr.lbal_addr = ap->ioaddr.cmd_addr +
244 (ATA_REG_LBAL << pdata->reg_shift);
245 ap->ioaddr.lbam_addr = ap->ioaddr.cmd_addr +
246 (ATA_REG_LBAM << pdata->reg_shift);
247 ap->ioaddr.lbah_addr = ap->ioaddr.cmd_addr +
248 (ATA_REG_LBAH << pdata->reg_shift);
249 ap->ioaddr.device_addr = ap->ioaddr.cmd_addr +
250 (ATA_REG_DEVICE << pdata->reg_shift);
251 ap->ioaddr.status_addr = ap->ioaddr.cmd_addr +
252 (ATA_REG_STATUS << pdata->reg_shift);
253 ap->ioaddr.command_addr = ap->ioaddr.cmd_addr +
254 (ATA_REG_CMD << pdata->reg_shift);
255
256 /*
257 * Allocate and load driver's internal data structure
258 */
259 data = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct pata_pxa_data),
260 GFP_KERNEL);
261 if (!data)
262 return -ENOMEM;
263
264 ap->private_data = data;
265
266 memset(&config, 0, sizeof(config));
267 config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
268 config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
269 config.src_addr = dma_res->start;
270 config.dst_addr = dma_res->start;
271 config.src_maxburst = 32;
272 config.dst_maxburst = 32;
273
274 /*
275 * Request the DMA channel
276 */
277 data->dma_chan = dma_request_chan(dev: &pdev->dev, name: "data");
278 if (IS_ERR(ptr: data->dma_chan))
279 return PTR_ERR(ptr: data->dma_chan);
280 ret = dmaengine_slave_config(chan: data->dma_chan, config: &config);
281 if (ret < 0) {
282 dev_err(&pdev->dev, "dma configuration failed: %d\n", ret);
283 return ret;
284 }
285
286 /*
287 * Activate the ATA host
288 */
289 ret = ata_host_activate(host, irq, irq_handler: ata_sff_interrupt,
290 irq_flags: pdata->irq_flags, sht: &pxa_ata_sht);
291 if (ret)
292 dma_release_channel(chan: data->dma_chan);
293
294 return ret;
295}
296
297static void pxa_ata_remove(struct platform_device *pdev)
298{
299 struct ata_host *host = platform_get_drvdata(pdev);
300 struct pata_pxa_data *data = host->ports[0]->private_data;
301
302 dma_release_channel(chan: data->dma_chan);
303
304 ata_host_detach(host);
305}
306
307static struct platform_driver pxa_ata_driver = {
308 .probe = pxa_ata_probe,
309 .remove_new = pxa_ata_remove,
310 .driver = {
311 .name = DRV_NAME,
312 },
313};
314
315module_platform_driver(pxa_ata_driver);
316
317MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
318MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU");
319MODULE_LICENSE("GPL");
320MODULE_VERSION(DRV_VERSION);
321MODULE_ALIAS("platform:" DRV_NAME);
322

source code of linux/drivers/ata/pata_pxa.c