xref: /openbmc/linux/drivers/ata/pata_sl82c105.c (revision 2a598d0b)
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 
31 enum {
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 
52 static 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 
78 static 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 
101 static 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 
115 static 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 
140 static 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 
161 static 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_stop		-	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 
190 static 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 
213 static 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 
231 static 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 
241 static const struct scsi_host_template sl82c105_sht = {
242 	ATA_BMDMA_SHT(DRV_NAME),
243 };
244 
245 static 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 
265 static 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 
293 static 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 
302 static 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
342 static 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 
358 static const struct pci_device_id sl82c105[] = {
359 	{ PCI_VDEVICE(WINBOND, PCI_DEVICE_ID_WINBOND_82C105), },
360 
361 	{ },
362 };
363 
364 static 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 
375 module_pci_driver(sl82c105_pci_driver);
376 
377 MODULE_AUTHOR("Alan Cox");
378 MODULE_DESCRIPTION("low-level driver for Sl82c105");
379 MODULE_LICENSE("GPL");
380 MODULE_DEVICE_TABLE(pci, sl82c105);
381 MODULE_VERSION(DRV_VERSION);
382