xref: /openbmc/linux/drivers/ata/pata_ns87415.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *    pata_ns87415.c - NS87415 (non PARISC) PATA
4  *
5  *	(C) 2005 Red Hat <alan@lxorguk.ukuu.org.uk>
6  *
7  *    This is a fairly generic MWDMA controller. It has some limitations
8  *    as it requires timing reloads on PIO/DMA transitions but it is otherwise
9  *    fairly well designed.
10  *
11  *    This driver assumes the firmware has left the chip in a valid ST506
12  *    compliant state, either legacy IRQ 14/15 or native INTA shared. You
13  *    may need to add platform code if your system fails to do this.
14  *
15  *    The same cell appears in the 87560 controller used by some PARISC
16  *    systems. This has its own special mountain of errata.
17  *
18  *    TODO:
19  *	Test PARISC SuperIO
20  *	Get someone to test on SPARC
21  *	Implement lazy pio/dma switching for better performance
22  *	8bit shared timing.
23  *	See if we need to kill the FIFO for ATAPI
24  */
25 
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/pci.h>
29 #include <linux/blkdev.h>
30 #include <linux/delay.h>
31 #include <linux/device.h>
32 #include <scsi/scsi_host.h>
33 #include <linux/libata.h>
34 #include <linux/ata.h>
35 
36 #define DRV_NAME	"pata_ns87415"
37 #define DRV_VERSION	"0.0.1"
38 
39 /**
40  *	ns87415_set_mode - Initialize host controller mode timings
41  *	@ap: Port whose timings we are configuring
42  *	@adev: Device whose timings we are configuring
43  *	@mode: Mode to set
44  *
45  *	Program the mode registers for this controller, channel and
46  *	device. Because the chip is quite an old design we have to do this
47  *	for PIO/DMA switches.
48  *
49  *	LOCKING:
50  *	None (inherited from caller).
51  */
52 
53 static void ns87415_set_mode(struct ata_port *ap, struct ata_device *adev, u8 mode)
54 {
55 	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
56 	int unit		= 2 * ap->port_no + adev->devno;
57 	int timing		= 0x44 + 2 * unit;
58 	unsigned long T		= 1000000000 / 33333;	/* PCI clocks */
59 	struct ata_timing t;
60 	u16 clocking;
61 	u8 iordy;
62 	u8 status;
63 
64 	/* Timing register format is 17 - low nybble read timing with
65 	   the high nybble being 16 - x for recovery time in PCI clocks */
66 
67 	ata_timing_compute(adev, adev->pio_mode, &t, T, 0);
68 
69 	clocking = 17 - clamp_val(t.active, 2, 17);
70 	clocking |= (16 - clamp_val(t.recover, 1, 16)) << 4;
71  	/* Use the same timing for read and write bytes */
72 	clocking |= (clocking << 8);
73 	pci_write_config_word(dev, timing, clocking);
74 
75 	/* Set the IORDY enable versus DMA enable on or off properly */
76 	pci_read_config_byte(dev, 0x42, &iordy);
77 	iordy &= ~(1 << (4 + unit));
78 	if (mode >= XFER_MW_DMA_0 || !ata_pio_need_iordy(adev))
79 		iordy |= (1 << (4 + unit));
80 
81 	/* Paranoia: We shouldn't ever get here with busy write buffers
82 	   but if so wait */
83 
84 	pci_read_config_byte(dev, 0x43, &status);
85 	while (status & 0x03) {
86 		udelay(1);
87 		pci_read_config_byte(dev, 0x43, &status);
88 	}
89 	/* Flip the IORDY/DMA bits now we are sure the write buffers are
90 	   clear */
91 	pci_write_config_byte(dev, 0x42, iordy);
92 
93 	/* TODO: Set byte 54 command timing to the best 8bit
94 	   mode shared by all four devices */
95 }
96 
97 /**
98  *	ns87415_set_piomode - Initialize host controller PATA PIO timings
99  *	@ap: Port whose timings we are configuring
100  *	@adev: Device to program
101  *
102  *	Set PIO mode for device, in host controller PCI config space.
103  *
104  *	LOCKING:
105  *	None (inherited from caller).
106  */
107 
108 static void ns87415_set_piomode(struct ata_port *ap, struct ata_device *adev)
109 {
110 	ns87415_set_mode(ap, adev, adev->pio_mode);
111 }
112 
113 /**
114  *	ns87415_bmdma_setup		-	Set up DMA
115  *	@qc: Command block
116  *
117  *	Set up for bus masterng DMA. We have to do this ourselves
118  *	rather than use the helper due to a chip erratum
119  */
120 
121 static void ns87415_bmdma_setup(struct ata_queued_cmd *qc)
122 {
123 	struct ata_port *ap = qc->ap;
124 	unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
125 	u8 dmactl;
126 
127 	/* load PRD table addr. */
128 	mb();	/* make sure PRD table writes are visible to controller */
129 	iowrite32(ap->bmdma_prd_dma, ap->ioaddr.bmdma_addr + ATA_DMA_TABLE_OFS);
130 
131 	/* specify data direction, triple-check start bit is clear */
132 	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
133 	dmactl &= ~(ATA_DMA_WR | ATA_DMA_START);
134 	/* Due to an erratum we need to write these bits to the wrong
135 	   place - which does save us an I/O bizarrely */
136 	dmactl |= ATA_DMA_INTR | ATA_DMA_ERR;
137 	if (!rw)
138 		dmactl |= ATA_DMA_WR;
139 	iowrite8(dmactl, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
140 	/* issue r/w command */
141 	ap->ops->sff_exec_command(ap, &qc->tf);
142 }
143 
144 /**
145  *	ns87415_bmdma_start		-	Begin DMA transfer
146  *	@qc: Command block
147  *
148  *	Switch the timings for the chip and set up for a DMA transfer
149  *	before the DMA burst begins.
150  *
151  *	FIXME: We should do lazy switching on bmdma_start versus
152  *	ata_pio_data_xfer for better performance.
153  */
154 
155 static void ns87415_bmdma_start(struct ata_queued_cmd *qc)
156 {
157 	ns87415_set_mode(qc->ap, qc->dev, qc->dev->dma_mode);
158 	ata_bmdma_start(qc);
159 }
160 
161 /**
162  *	ns87415_bmdma_stop		-	End DMA transfer
163  *	@qc: Command block
164  *
165  *	End DMA mode and switch the controller back into PIO mode
166  */
167 
168 static void ns87415_bmdma_stop(struct ata_queued_cmd *qc)
169 {
170 	ata_bmdma_stop(qc);
171 	ns87415_set_mode(qc->ap, qc->dev, qc->dev->pio_mode);
172 }
173 
174 /**
175  *	ns87415_irq_clear		-	Clear interrupt
176  *	@ap: Channel to clear
177  *
178  *	Erratum: Due to a chip bug regisers 02 and 0A bit 1 and 2 (the
179  *	error bits) are reset by writing to register 00 or 08.
180  */
181 
182 static void ns87415_irq_clear(struct ata_port *ap)
183 {
184 	void __iomem *mmio = ap->ioaddr.bmdma_addr;
185 
186 	if (!mmio)
187 		return;
188 	iowrite8((ioread8(mmio + ATA_DMA_CMD) | ATA_DMA_INTR | ATA_DMA_ERR),
189 			mmio + ATA_DMA_CMD);
190 }
191 
192 /**
193  *	ns87415_check_atapi_dma		-	ATAPI DMA filter
194  *	@qc: Command block
195  *
196  *	Disable ATAPI DMA (for now). We may be able to do DMA if we
197  *	kill the prefetching. This isn't clear.
198  */
199 
200 static int ns87415_check_atapi_dma(struct ata_queued_cmd *qc)
201 {
202 	return -EOPNOTSUPP;
203 }
204 
205 #if defined(CONFIG_SUPERIO)
206 
207 /* SUPERIO 87560 is a PoS chip that NatSem denies exists.
208  * Unfortunately, it's built-in on all Astro-based PA-RISC workstations
209  * which use the integrated NS87514 cell for CD-ROM support.
210  * i.e we have to support for CD-ROM installs.
211  * See drivers/parisc/superio.c for more gory details.
212  *
213  * Workarounds taken from drivers/ide/pci/ns87415.c
214  */
215 
216 #include <asm/superio.h>
217 
218 #define SUPERIO_IDE_MAX_RETRIES 25
219 
220 /**
221  *	ns87560_read_buggy	-	workaround buggy Super I/O chip
222  *	@port: Port to read
223  *
224  *	Work around chipset problems in the 87560 SuperIO chip
225  */
226 
227 static u8 ns87560_read_buggy(void __iomem *port)
228 {
229 	u8 tmp;
230 	int retries = SUPERIO_IDE_MAX_RETRIES;
231 	do {
232 		tmp = ioread8(port);
233 		if (tmp != 0)
234 			return tmp;
235 		udelay(50);
236 	} while(retries-- > 0);
237 	return tmp;
238 }
239 
240 /**
241  *	ns87560_check_status
242  *	@ap: channel to check
243  *
244  *	Return the status of the channel working around the
245  *	87560 flaws.
246  */
247 
248 static u8 ns87560_check_status(struct ata_port *ap)
249 {
250 	return ns87560_read_buggy(ap->ioaddr.status_addr);
251 }
252 
253 /**
254  *	ns87560_tf_read - input device's ATA taskfile shadow registers
255  *	@ap: Port from which input is read
256  *	@tf: ATA taskfile register set for storing input
257  *
258  *	Reads ATA taskfile registers for currently-selected device
259  *	into @tf. Work around the 87560 bugs.
260  *
261  *	LOCKING:
262  *	Inherited from caller.
263  */
264 void ns87560_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
265 {
266 	struct ata_ioports *ioaddr = &ap->ioaddr;
267 
268 	tf->command = ns87560_check_status(ap);
269 	tf->feature = ioread8(ioaddr->error_addr);
270 	tf->nsect = ioread8(ioaddr->nsect_addr);
271 	tf->lbal = ioread8(ioaddr->lbal_addr);
272 	tf->lbam = ioread8(ioaddr->lbam_addr);
273 	tf->lbah = ioread8(ioaddr->lbah_addr);
274 	tf->device = ns87560_read_buggy(ioaddr->device_addr);
275 
276 	if (tf->flags & ATA_TFLAG_LBA48) {
277 		iowrite8(tf->ctl | ATA_HOB, ioaddr->ctl_addr);
278 		tf->hob_feature = ioread8(ioaddr->error_addr);
279 		tf->hob_nsect = ioread8(ioaddr->nsect_addr);
280 		tf->hob_lbal = ioread8(ioaddr->lbal_addr);
281 		tf->hob_lbam = ioread8(ioaddr->lbam_addr);
282 		tf->hob_lbah = ioread8(ioaddr->lbah_addr);
283 		iowrite8(tf->ctl, ioaddr->ctl_addr);
284 		ap->last_ctl = tf->ctl;
285 	}
286 }
287 
288 /**
289  *	ns87560_bmdma_status
290  *	@ap: channel to check
291  *
292  *	Return the DMA status of the channel working around the
293  *	87560 flaws.
294  */
295 
296 static u8 ns87560_bmdma_status(struct ata_port *ap)
297 {
298 	return ns87560_read_buggy(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
299 }
300 #endif		/* 87560 SuperIO Support */
301 
302 static struct ata_port_operations ns87415_pata_ops = {
303 	.inherits		= &ata_bmdma_port_ops,
304 
305 	.check_atapi_dma	= ns87415_check_atapi_dma,
306 	.bmdma_setup		= ns87415_bmdma_setup,
307 	.bmdma_start		= ns87415_bmdma_start,
308 	.bmdma_stop		= ns87415_bmdma_stop,
309 	.sff_irq_clear		= ns87415_irq_clear,
310 
311 	.cable_detect		= ata_cable_40wire,
312 	.set_piomode		= ns87415_set_piomode,
313 };
314 
315 #if defined(CONFIG_SUPERIO)
316 static struct ata_port_operations ns87560_pata_ops = {
317 	.inherits		= &ns87415_pata_ops,
318 	.sff_tf_read		= ns87560_tf_read,
319 	.sff_check_status	= ns87560_check_status,
320 	.bmdma_status		= ns87560_bmdma_status,
321 };
322 #endif
323 
324 static struct scsi_host_template ns87415_sht = {
325 	ATA_BMDMA_SHT(DRV_NAME),
326 };
327 
328 static void ns87415_fixup(struct pci_dev *pdev)
329 {
330 	/* Select 512 byte sectors */
331 	pci_write_config_byte(pdev, 0x55, 0xEE);
332 	/* Select PIO0 8bit clocking */
333 	pci_write_config_byte(pdev, 0x54, 0xB7);
334 }
335 
336 /**
337  *	ns87415_init_one - Register 87415 ATA PCI device with kernel services
338  *	@pdev: PCI device to register
339  *	@ent: Entry in ns87415_pci_tbl matching with @pdev
340  *
341  *	Called from kernel PCI layer.  We probe for combined mode (sigh),
342  *	and then hand over control to libata, for it to do the rest.
343  *
344  *	LOCKING:
345  *	Inherited from PCI layer (may sleep).
346  *
347  *	RETURNS:
348  *	Zero on success, or -ERRNO value.
349  */
350 
351 static int ns87415_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
352 {
353 	static const struct ata_port_info info = {
354 		.flags		= ATA_FLAG_SLAVE_POSS,
355 		.pio_mask	= ATA_PIO4,
356 		.mwdma_mask	= ATA_MWDMA2,
357 		.port_ops	= &ns87415_pata_ops,
358 	};
359 	const struct ata_port_info *ppi[] = { &info, NULL };
360 	int rc;
361 #if defined(CONFIG_SUPERIO)
362 	static const struct ata_port_info info87560 = {
363 		.flags		= ATA_FLAG_SLAVE_POSS,
364 		.pio_mask	= ATA_PIO4,
365 		.mwdma_mask	= ATA_MWDMA2,
366 		.port_ops	= &ns87560_pata_ops,
367 	};
368 
369 	if (PCI_SLOT(pdev->devfn) == 0x0E)
370 		ppi[0] = &info87560;
371 #endif
372 	ata_print_version_once(&pdev->dev, DRV_VERSION);
373 
374 	rc = pcim_enable_device(pdev);
375 	if (rc)
376 		return rc;
377 
378 	ns87415_fixup(pdev);
379 
380 	return ata_pci_bmdma_init_one(pdev, ppi, &ns87415_sht, NULL, 0);
381 }
382 
383 static const struct pci_device_id ns87415_pci_tbl[] = {
384 	{ PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_87415), },
385 
386 	{ }	/* terminate list */
387 };
388 
389 #ifdef CONFIG_PM_SLEEP
390 static int ns87415_reinit_one(struct pci_dev *pdev)
391 {
392 	struct ata_host *host = pci_get_drvdata(pdev);
393 	int rc;
394 
395 	rc = ata_pci_device_do_resume(pdev);
396 	if (rc)
397 		return rc;
398 
399 	ns87415_fixup(pdev);
400 
401 	ata_host_resume(host);
402 	return 0;
403 }
404 #endif
405 
406 static struct pci_driver ns87415_pci_driver = {
407 	.name			= DRV_NAME,
408 	.id_table		= ns87415_pci_tbl,
409 	.probe			= ns87415_init_one,
410 	.remove			= ata_pci_remove_one,
411 #ifdef CONFIG_PM_SLEEP
412 	.suspend		= ata_pci_device_suspend,
413 	.resume			= ns87415_reinit_one,
414 #endif
415 };
416 
417 module_pci_driver(ns87415_pci_driver);
418 
419 MODULE_AUTHOR("Alan Cox");
420 MODULE_DESCRIPTION("ATA low-level driver for NS87415 controllers");
421 MODULE_LICENSE("GPL");
422 MODULE_DEVICE_TABLE(pci, ns87415_pci_tbl);
423 MODULE_VERSION(DRV_VERSION);
424