1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * pata_sl82c105.c 	- SL82C105 PATA for new ATA layer
4 *			  (C) 2005 Red Hat Inc
5 *			  (C) 2011 Bartlomiej Zolnierkiewicz
6 *
7 * Based in part on linux/drivers/ide/pci/sl82c105.c
8 * 		SL82C105/Winbond 553 IDE driver
9 *
10 * and in part on the documentation and errata sheet
11 *
12 *
13 * Note: The controller like many controllers has shared timings for
14 * PIO and DMA. We thus flip to the DMA timings in dma_start and flip back
15 * in the dma_stop function. Thus we actually don't need a set_dmamode
16 * method as the PIO method is always called and will set the right PIO
17 * timing parameters.
18 */
19
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/pci.h>
23#include <linux/blkdev.h>
24#include <linux/delay.h>
25#include <scsi/scsi_host.h>
26#include <linux/libata.h>
27
28#define DRV_NAME "pata_sl82c105"
29#define DRV_VERSION "0.3.3"
30
31enum {
32	/*
33	 * SL82C105 PCI config register 0x40 bits.
34	 */
35	CTRL_IDE_IRQB	=	(1 << 30),
36	CTRL_IDE_IRQA   =	(1 << 28),
37	CTRL_LEGIRQ     =	(1 << 11),
38	CTRL_P1F16      =	(1 << 5),
39	CTRL_P1EN       =	(1 << 4),
40	CTRL_P0F16      =	(1 << 1),
41	CTRL_P0EN       =	(1 << 0)
42};
43
44/**
45 *	sl82c105_pre_reset		-	probe begin
46 *	@link: ATA link
47 *	@deadline: deadline jiffies for the operation
48 *
49 *	Set up cable type and use generic probe init
50 */
51
52static int sl82c105_pre_reset(struct ata_link *link, unsigned long deadline)
53{
54	static const struct pci_bits sl82c105_enable_bits[] = {
55		{ 0x40, 1, 0x01, 0x01 },
56		{ 0x40, 1, 0x10, 0x10 }
57	};
58	struct ata_port *ap = link->ap;
59	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
60
61	if (ap->port_no && !pci_test_config_bits(pdev, &sl82c105_enable_bits[ap->port_no]))
62		return -ENOENT;
63	return ata_sff_prereset(link, deadline);
64}
65
66
67/**
68 *	sl82c105_configure_piomode	-	set chip PIO timing
69 *	@ap: ATA interface
70 *	@adev: ATA device
71 *	@pio: PIO mode
72 *
73 *	Called to do the PIO mode setup. Our timing registers are shared
74 *	so a configure_dmamode call will undo any work we do here and vice
75 *	versa
76 */
77
78static void sl82c105_configure_piomode(struct ata_port *ap, struct ata_device *adev, int pio)
79{
80	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
81	static u16 pio_timing[5] = {
82		0x50D, 0x407, 0x304, 0x242, 0x240
83	};
84	u16 dummy;
85	int timing = 0x44 + (8 * ap->port_no) + (4 * adev->devno);
86
87	pci_write_config_word(pdev, timing, pio_timing[pio]);
88	/* Can we lose this oddity of the old driver */
89	pci_read_config_word(pdev, timing, &dummy);
90}
91
92/**
93 *	sl82c105_set_piomode	-	set initial PIO mode data
94 *	@ap: ATA interface
95 *	@adev: ATA device
96 *
97 *	Called to do the PIO mode setup. Our timing registers are shared
98 *	but we want to set the PIO timing by default.
99 */
100
101static void sl82c105_set_piomode(struct ata_port *ap, struct ata_device *adev)
102{
103	sl82c105_configure_piomode(ap, adev, adev->pio_mode - XFER_PIO_0);
104}
105
106/**
107 *	sl82c105_configure_dmamode	-	set DMA mode in chip
108 *	@ap: ATA interface
109 *	@adev: ATA device
110 *
111 *	Load DMA cycle times into the chip ready for a DMA transfer
112 *	to occur.
113 */
114
115static void sl82c105_configure_dmamode(struct ata_port *ap, struct ata_device *adev)
116{
117	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
118	static u16 dma_timing[3] = {
119		0x707, 0x201, 0x200
120	};
121	u16 dummy;
122	int timing = 0x44 + (8 * ap->port_no) + (4 * adev->devno);
123	int dma = adev->dma_mode - XFER_MW_DMA_0;
124
125	pci_write_config_word(pdev, timing, dma_timing[dma]);
126	/* Can we lose this oddity of the old driver */
127	pci_read_config_word(pdev, timing, &dummy);
128}
129
130/**
131 *	sl82c105_reset_engine	-	Reset the DMA engine
132 *	@ap: ATA interface
133 *
134 *	The sl82c105 has some serious problems with the DMA engine
135 *	when transfers don't run as expected or ATAPI is used. The
136 *	recommended fix is to reset the engine each use using a chip
137 *	test register.
138 */
139
140static void sl82c105_reset_engine(struct ata_port *ap)
141{
142	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
143	u16 val;
144
145	pci_read_config_word(pdev, 0x7E, &val);
146	pci_write_config_word(pdev, 0x7E, val | 4);
147	pci_write_config_word(pdev, 0x7E, val & ~4);
148}
149
150/**
151 *	sl82c105_bmdma_start		-	DMA engine begin
152 *	@qc: ATA command
153 *
154 *	Reset the DMA engine each use as recommended by the errata
155 *	document.
156 *
157 *	FIXME: if we switch clock at BMDMA start/end we might get better
158 *	PIO performance on DMA capable devices.
159 */
160
161static void sl82c105_bmdma_start(struct ata_queued_cmd *qc)
162{
163	struct ata_port *ap = qc->ap;
164
165	udelay(100);
166	sl82c105_reset_engine(ap);
167	udelay(100);
168
169	/* Set the clocks for DMA */
170	sl82c105_configure_dmamode(ap, qc->dev);
171	/* Activate DMA */
172	ata_bmdma_start(qc);
173}
174
175/**
176 *	sl82c105_bmdma_end		-	DMA engine stop
177 *	@qc: ATA command
178 *
179 *	Reset the DMA engine each use as recommended by the errata
180 *	document.
181 *
182 *	This function is also called to turn off DMA when a timeout occurs
183 *	during DMA operation. In both cases we need to reset the engine,
184 *	so no actual eng_timeout handler is required.
185 *
186 *	We assume bmdma_stop is always called if bmdma_start as called. If
187 *	not then we may need to wrap qc_issue.
188 */
189
190static void sl82c105_bmdma_stop(struct ata_queued_cmd *qc)
191{
192	struct ata_port *ap = qc->ap;
193
194	ata_bmdma_stop(qc);
195	sl82c105_reset_engine(ap);
196	udelay(100);
197
198	/* This will redo the initial setup of the DMA device to matching
199	   PIO timings */
200	sl82c105_set_piomode(ap, qc->dev);
201}
202
203/**
204 *	sl82c105_qc_defer	-	implement serialization
205 *	@qc: command
206 *
207 *	We must issue one command per host not per channel because
208 *	of the reset bug.
209 *
210 *	Q: is the scsi host lock sufficient ?
211 */
212
213static int sl82c105_qc_defer(struct ata_queued_cmd *qc)
214{
215	struct ata_host *host = qc->ap->host;
216	struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
217	int rc;
218
219	/* First apply the usual rules */
220	rc = ata_std_qc_defer(qc);
221	if (rc != 0)
222		return rc;
223
224	/* Now apply serialization rules. Only allow a command if the
225	   other channel state machine is idle */
226	if (alt && alt->qc_active)
227		return	ATA_DEFER_PORT;
228	return 0;
229}
230
231static bool sl82c105_sff_irq_check(struct ata_port *ap)
232{
233	struct pci_dev *pdev	= to_pci_dev(ap->host->dev);
234	u32 val, mask		= ap->port_no ? CTRL_IDE_IRQB : CTRL_IDE_IRQA;
235
236	pci_read_config_dword(pdev, 0x40, &val);
237
238	return val & mask;
239}
240
241static struct scsi_host_template sl82c105_sht = {
242	ATA_BMDMA_SHT(DRV_NAME),
243};
244
245static struct ata_port_operations sl82c105_port_ops = {
246	.inherits	= &ata_bmdma_port_ops,
247	.qc_defer	= sl82c105_qc_defer,
248	.bmdma_start 	= sl82c105_bmdma_start,
249	.bmdma_stop	= sl82c105_bmdma_stop,
250	.cable_detect	= ata_cable_40wire,
251	.set_piomode	= sl82c105_set_piomode,
252	.prereset	= sl82c105_pre_reset,
253	.sff_irq_check	= sl82c105_sff_irq_check,
254};
255
256/**
257 *	sl82c105_bridge_revision	-	find bridge version
258 *	@pdev: PCI device for the ATA function
259 *
260 *	Locates the PCI bridge associated with the ATA function and
261 *	providing it is a Winbond 553 reports the revision. If it cannot
262 *	find a revision or the right device it returns -1
263 */
264
265static int sl82c105_bridge_revision(struct pci_dev *pdev)
266{
267	struct pci_dev *bridge;
268
269	/*
270	 * The bridge should be part of the same device, but function 0.
271	 */
272	bridge = pci_get_slot(pdev->bus,
273			       PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
274	if (!bridge)
275		return -1;
276
277	/*
278	 * Make sure it is a Winbond 553 and is an ISA bridge.
279	 */
280	if (bridge->vendor != PCI_VENDOR_ID_WINBOND ||
281	    bridge->device != PCI_DEVICE_ID_WINBOND_83C553 ||
282	    bridge->class >> 8 != PCI_CLASS_BRIDGE_ISA) {
283	    	pci_dev_put(bridge);
284		return -1;
285	}
286	/*
287	 * We need to find function 0's revision, not function 1
288	 */
289	pci_dev_put(bridge);
290	return bridge->revision;
291}
292
293static void sl82c105_fixup(struct pci_dev *pdev)
294{
295	u32 val;
296
297	pci_read_config_dword(pdev, 0x40, &val);
298	val |= CTRL_P0EN | CTRL_P0F16 | CTRL_P1F16;
299	pci_write_config_dword(pdev, 0x40, val);
300}
301
302static int sl82c105_init_one(struct pci_dev *dev, const struct pci_device_id *id)
303{
304	static const struct ata_port_info info_dma = {
305		.flags = ATA_FLAG_SLAVE_POSS,
306		.pio_mask = ATA_PIO4,
307		.mwdma_mask = ATA_MWDMA2,
308		.port_ops = &sl82c105_port_ops
309	};
310	static const struct ata_port_info info_early = {
311		.flags = ATA_FLAG_SLAVE_POSS,
312		.pio_mask = ATA_PIO4,
313		.port_ops = &sl82c105_port_ops
314	};
315	/* for now use only the first port */
316	const struct ata_port_info *ppi[] = { &info_early,
317					       NULL };
318	int rev;
319	int rc;
320
321	rc = pcim_enable_device(dev);
322	if (rc)
323		return rc;
324
325	rev = sl82c105_bridge_revision(dev);
326
327	if (rev == -1)
328		dev_warn(&dev->dev,
329			 "pata_sl82c105: Unable to find bridge, disabling DMA\n");
330	else if (rev <= 5)
331		dev_warn(&dev->dev,
332			 "pata_sl82c105: Early bridge revision, no DMA available\n");
333	else
334		ppi[0] = &info_dma;
335
336	sl82c105_fixup(dev);
337
338	return ata_pci_bmdma_init_one(dev, ppi, &sl82c105_sht, NULL, 0);
339}
340
341#ifdef CONFIG_PM_SLEEP
342static int sl82c105_reinit_one(struct pci_dev *pdev)
343{
344	struct ata_host *host = pci_get_drvdata(pdev);
345	int rc;
346
347	rc = ata_pci_device_do_resume(pdev);
348	if (rc)
349		return rc;
350
351	sl82c105_fixup(pdev);
352
353	ata_host_resume(host);
354	return 0;
355}
356#endif
357
358static const struct pci_device_id sl82c105[] = {
359	{ PCI_VDEVICE(WINBOND, PCI_DEVICE_ID_WINBOND_82C105), },
360
361	{ },
362};
363
364static struct pci_driver sl82c105_pci_driver = {
365	.name 		= DRV_NAME,
366	.id_table	= sl82c105,
367	.probe 		= sl82c105_init_one,
368	.remove		= ata_pci_remove_one,
369#ifdef CONFIG_PM_SLEEP
370	.suspend	= ata_pci_device_suspend,
371	.resume		= sl82c105_reinit_one,
372#endif
373};
374
375module_pci_driver(sl82c105_pci_driver);
376
377MODULE_AUTHOR("Alan Cox");
378MODULE_DESCRIPTION("low-level driver for Sl82c105");
379MODULE_LICENSE("GPL");
380MODULE_DEVICE_TABLE(pci, sl82c105);
381MODULE_VERSION(DRV_VERSION);
382