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(pd->dma_chan, 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(pd->dma_chan, qc->sg, qc->n_elem, dir,
58				     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(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(&pd->dma_done);
86	dma_async_issue_pending(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(pd->dma_chan, pd->dma_cookie, NULL);
98	if (status != DMA_ERROR && status != DMA_COMPLETE &&
99	    wait_for_completion_timeout(&pd->dma_done, HZ))
100		ata_dev_err(qc->dev, "Timeout waiting for DMA completion!");
101
102	dmaengine_terminate_all(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(pd->dma_chan, pd->dma_cookie, &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(&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(&pdev->dev, 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(&pdev->dev, cmd_res->start,
225						resource_size(cmd_res));
226	ap->ioaddr.ctl_addr	= devm_ioremap(&pdev->dev, ctl_res->start,
227						resource_size(ctl_res));
228	ap->ioaddr.bmdma_addr	= devm_ioremap(&pdev->dev, dma_res->start,
229						resource_size(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(&pdev->dev, 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(&pdev->dev, "data");
278	if (IS_ERR(data->dma_chan))
279		return PTR_ERR(data->dma_chan);
280	ret = dmaengine_slave_config(data->dma_chan, &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, ata_sff_interrupt,
290				pdata->irq_flags, &pxa_ata_sht);
291	if (ret)
292		dma_release_channel(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(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