1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * EP93XX PATA controller driver.
4 *
5 * Copyright (c) 2012, Metasoft s.c.
6 *	Rafal Prylowski <prylowski@metasoft.pl>
7 *
8 * Based on pata_scc.c, pata_icside.c and on earlier version of EP93XX
9 * PATA driver by Lennert Buytenhek and Alessandro Zummo.
10 * Read/Write timings, resource management and other improvements
11 * from driver by Joao Ramos and Bartlomiej Zolnierkiewicz.
12 * DMA engine support based on spi-ep93xx.c by Mika Westerberg.
13 *
14 * Original copyrights:
15 *
16 * Support for Cirrus Logic's EP93xx (EP9312, EP9315) CPUs
17 * PATA host controller driver.
18 *
19 * Copyright (c) 2009, Bartlomiej Zolnierkiewicz
20 *
21 * Heavily based on the ep93xx-ide.c driver:
22 *
23 * Copyright (c) 2009, Joao Ramos <joao.ramos@inov.pt>
24 *		      INESC Inovacao (INOV)
25 *
26 * EP93XX PATA controller driver.
27 * Copyright (C) 2007 Lennert Buytenhek <buytenh@wantstofly.org>
28 *
29 * An ATA driver for the Cirrus Logic EP93xx PATA controller.
30 *
31 * Based on an earlier version by Alessandro Zummo, which is:
32 *   Copyright (C) 2006 Tower Technologies
33 */
34
35#include <linux/err.h>
36#include <linux/kernel.h>
37#include <linux/module.h>
38#include <linux/blkdev.h>
39#include <scsi/scsi_host.h>
40#include <linux/ata.h>
41#include <linux/libata.h>
42#include <linux/platform_device.h>
43#include <linux/delay.h>
44#include <linux/dmaengine.h>
45#include <linux/ktime.h>
46
47#include <linux/platform_data/dma-ep93xx.h>
48#include <linux/soc/cirrus/ep93xx.h>
49
50#define DRV_NAME	"ep93xx-ide"
51#define DRV_VERSION	"1.0"
52
53enum {
54	/* IDE Control Register */
55	IDECTRL				= 0x00,
56	IDECTRL_CS0N			= (1 << 0),
57	IDECTRL_CS1N			= (1 << 1),
58	IDECTRL_DIORN			= (1 << 5),
59	IDECTRL_DIOWN			= (1 << 6),
60	IDECTRL_INTRQ			= (1 << 9),
61	IDECTRL_IORDY			= (1 << 10),
62	/*
63	 * the device IDE register to be accessed is selected through
64	 * IDECTRL register's specific bitfields 'DA', 'CS1N' and 'CS0N':
65	 *   b4   b3   b2    b1     b0
66	 *   A2   A1   A0   CS1N   CS0N
67	 * the values filled in this structure allows the value to be directly
68	 * ORed to the IDECTRL register, hence giving directly the A[2:0] and
69	 * CS1N/CS0N values for each IDE register.
70	 * The values correspond to the transformation:
71	 *   ((real IDE address) << 2) | CS1N value << 1 | CS0N value
72	 */
73	IDECTRL_ADDR_CMD		= 0 + 2, /* CS1 */
74	IDECTRL_ADDR_DATA		= (ATA_REG_DATA << 2) + 2,
75	IDECTRL_ADDR_ERROR		= (ATA_REG_ERR << 2) + 2,
76	IDECTRL_ADDR_FEATURE		= (ATA_REG_FEATURE << 2) + 2,
77	IDECTRL_ADDR_NSECT		= (ATA_REG_NSECT << 2) + 2,
78	IDECTRL_ADDR_LBAL		= (ATA_REG_LBAL << 2) + 2,
79	IDECTRL_ADDR_LBAM		= (ATA_REG_LBAM << 2) + 2,
80	IDECTRL_ADDR_LBAH		= (ATA_REG_LBAH << 2) + 2,
81	IDECTRL_ADDR_DEVICE		= (ATA_REG_DEVICE << 2) + 2,
82	IDECTRL_ADDR_STATUS		= (ATA_REG_STATUS << 2) + 2,
83	IDECTRL_ADDR_COMMAND		= (ATA_REG_CMD << 2) + 2,
84	IDECTRL_ADDR_ALTSTATUS		= (0x06 << 2) + 1, /* CS0 */
85	IDECTRL_ADDR_CTL		= (0x06 << 2) + 1, /* CS0 */
86
87	/* IDE Configuration Register */
88	IDECFG				= 0x04,
89	IDECFG_IDEEN			= (1 << 0),
90	IDECFG_PIO			= (1 << 1),
91	IDECFG_MDMA			= (1 << 2),
92	IDECFG_UDMA			= (1 << 3),
93	IDECFG_MODE_SHIFT		= 4,
94	IDECFG_MODE_MASK		= (0xf << 4),
95	IDECFG_WST_SHIFT		= 8,
96	IDECFG_WST_MASK			= (0x3 << 8),
97
98	/* MDMA Operation Register */
99	IDEMDMAOP			= 0x08,
100
101	/* UDMA Operation Register */
102	IDEUDMAOP			= 0x0c,
103	IDEUDMAOP_UEN			= (1 << 0),
104	IDEUDMAOP_RWOP			= (1 << 1),
105
106	/* PIO/MDMA/UDMA Data Registers */
107	IDEDATAOUT			= 0x10,
108	IDEDATAIN			= 0x14,
109	IDEMDMADATAOUT			= 0x18,
110	IDEMDMADATAIN			= 0x1c,
111	IDEUDMADATAOUT			= 0x20,
112	IDEUDMADATAIN			= 0x24,
113
114	/* UDMA Status Register */
115	IDEUDMASTS			= 0x28,
116	IDEUDMASTS_DMAIDE		= (1 << 16),
117	IDEUDMASTS_INTIDE		= (1 << 17),
118	IDEUDMASTS_SBUSY		= (1 << 18),
119	IDEUDMASTS_NDO			= (1 << 24),
120	IDEUDMASTS_NDI			= (1 << 25),
121	IDEUDMASTS_N4X			= (1 << 26),
122
123	/* UDMA Debug Status Register */
124	IDEUDMADEBUG			= 0x2c,
125};
126
127struct ep93xx_pata_data {
128	const struct platform_device *pdev;
129	void __iomem *ide_base;
130	struct ata_timing t;
131	bool iordy;
132
133	unsigned long udma_in_phys;
134	unsigned long udma_out_phys;
135
136	struct dma_chan *dma_rx_channel;
137	struct ep93xx_dma_data dma_rx_data;
138	struct dma_chan *dma_tx_channel;
139	struct ep93xx_dma_data dma_tx_data;
140};
141
142static void ep93xx_pata_clear_regs(void __iomem *base)
143{
144	writel(IDECTRL_CS0N | IDECTRL_CS1N | IDECTRL_DIORN |
145		IDECTRL_DIOWN, base + IDECTRL);
146
147	writel(0, base + IDECFG);
148	writel(0, base + IDEMDMAOP);
149	writel(0, base + IDEUDMAOP);
150	writel(0, base + IDEDATAOUT);
151	writel(0, base + IDEDATAIN);
152	writel(0, base + IDEMDMADATAOUT);
153	writel(0, base + IDEMDMADATAIN);
154	writel(0, base + IDEUDMADATAOUT);
155	writel(0, base + IDEUDMADATAIN);
156	writel(0, base + IDEUDMADEBUG);
157}
158
159static bool ep93xx_pata_check_iordy(void __iomem *base)
160{
161	return !!(readl(base + IDECTRL) & IDECTRL_IORDY);
162}
163
164/*
165 * According to EP93xx User's Guide, WST field of IDECFG specifies number
166 * of HCLK cycles to hold the data bus after a PIO write operation.
167 * It should be programmed to guarantee following delays:
168 *
169 * PIO Mode   [ns]
170 * 0          30
171 * 1          20
172 * 2          15
173 * 3          10
174 * 4          5
175 *
176 * Maximum possible value for HCLK is 100MHz.
177 */
178static int ep93xx_pata_get_wst(int pio_mode)
179{
180	int val;
181
182	if (pio_mode == 0)
183		val = 3;
184	else if (pio_mode < 3)
185		val = 2;
186	else
187		val = 1;
188
189	return val << IDECFG_WST_SHIFT;
190}
191
192static void ep93xx_pata_enable_pio(void __iomem *base, int pio_mode)
193{
194	writel(IDECFG_IDEEN | IDECFG_PIO |
195		ep93xx_pata_get_wst(pio_mode) |
196		(pio_mode << IDECFG_MODE_SHIFT), base + IDECFG);
197}
198
199/*
200 * Based on delay loop found in mach-pxa/mp900.c.
201 *
202 * Single iteration should take 5 cpu cycles. This is 25ns assuming the
203 * fastest ep93xx cpu speed (200MHz) and is better optimized for PIO4 timings
204 * than eg. 20ns.
205 */
206static void ep93xx_pata_delay(unsigned long count)
207{
208	__asm__ volatile (
209		"0:\n"
210		"mov r0, r0\n"
211		"subs %0, %1, #1\n"
212		"bge 0b\n"
213		: "=r" (count)
214		: "0" (count)
215	);
216}
217
218static unsigned long ep93xx_pata_wait_for_iordy(void __iomem *base,
219						unsigned long t2)
220{
221	/*
222	 * According to ATA specification, IORDY pin can be first sampled
223	 * tA = 35ns after activation of DIOR-/DIOW-. Maximum IORDY pulse
224	 * width is tB = 1250ns.
225	 *
226	 * We are already t2 delay loop iterations after activation of
227	 * DIOR-/DIOW-, so we set timeout to (1250 + 35) / 25 - t2 additional
228	 * delay loop iterations.
229	 */
230	unsigned long start = (1250 + 35) / 25 - t2;
231	unsigned long counter = start;
232
233	while (!ep93xx_pata_check_iordy(base) && counter--)
234		ep93xx_pata_delay(1);
235	return start - counter;
236}
237
238/* common part at start of ep93xx_pata_read/write() */
239static void ep93xx_pata_rw_begin(void __iomem *base, unsigned long addr,
240				 unsigned long t1)
241{
242	writel(IDECTRL_DIOWN | IDECTRL_DIORN | addr, base + IDECTRL);
243	ep93xx_pata_delay(t1);
244}
245
246/* common part at end of ep93xx_pata_read/write() */
247static void ep93xx_pata_rw_end(void __iomem *base, unsigned long addr,
248			       bool iordy, unsigned long t0, unsigned long t2,
249			       unsigned long t2i)
250{
251	ep93xx_pata_delay(t2);
252	/* lengthen t2 if needed */
253	if (iordy)
254		t2 += ep93xx_pata_wait_for_iordy(base, t2);
255	writel(IDECTRL_DIOWN | IDECTRL_DIORN | addr, base + IDECTRL);
256	if (t0 > t2 && t0 - t2 > t2i)
257		ep93xx_pata_delay(t0 - t2);
258	else
259		ep93xx_pata_delay(t2i);
260}
261
262static u16 ep93xx_pata_read(struct ep93xx_pata_data *drv_data,
263			    unsigned long addr,
264			    bool reg)
265{
266	void __iomem *base = drv_data->ide_base;
267	const struct ata_timing *t = &drv_data->t;
268	unsigned long t0 = reg ? t->cyc8b : t->cycle;
269	unsigned long t2 = reg ? t->act8b : t->active;
270	unsigned long t2i = reg ? t->rec8b : t->recover;
271
272	ep93xx_pata_rw_begin(base, addr, t->setup);
273	writel(IDECTRL_DIOWN | addr, base + IDECTRL);
274	/*
275	 * The IDEDATAIN register is loaded from the DD pins at the positive
276	 * edge of the DIORN signal. (EP93xx UG p27-14)
277	 */
278	ep93xx_pata_rw_end(base, addr, drv_data->iordy, t0, t2, t2i);
279	return readl(base + IDEDATAIN);
280}
281
282/* IDE register read */
283static u16 ep93xx_pata_read_reg(struct ep93xx_pata_data *drv_data,
284				unsigned long addr)
285{
286	return ep93xx_pata_read(drv_data, addr, true);
287}
288
289/* PIO data read */
290static u16 ep93xx_pata_read_data(struct ep93xx_pata_data *drv_data,
291				 unsigned long addr)
292{
293	return ep93xx_pata_read(drv_data, addr, false);
294}
295
296static void ep93xx_pata_write(struct ep93xx_pata_data *drv_data,
297			      u16 value, unsigned long addr,
298			      bool reg)
299{
300	void __iomem *base = drv_data->ide_base;
301	const struct ata_timing *t = &drv_data->t;
302	unsigned long t0 = reg ? t->cyc8b : t->cycle;
303	unsigned long t2 = reg ? t->act8b : t->active;
304	unsigned long t2i = reg ? t->rec8b : t->recover;
305
306	ep93xx_pata_rw_begin(base, addr, t->setup);
307	/*
308	 * Value from IDEDATAOUT register is driven onto the DD pins when
309	 * DIOWN is low. (EP93xx UG p27-13)
310	 */
311	writel(value, base + IDEDATAOUT);
312	writel(IDECTRL_DIORN | addr, base + IDECTRL);
313	ep93xx_pata_rw_end(base, addr, drv_data->iordy, t0, t2, t2i);
314}
315
316/* IDE register write */
317static void ep93xx_pata_write_reg(struct ep93xx_pata_data *drv_data,
318				  u16 value, unsigned long addr)
319{
320	ep93xx_pata_write(drv_data, value, addr, true);
321}
322
323/* PIO data write */
324static void ep93xx_pata_write_data(struct ep93xx_pata_data *drv_data,
325				   u16 value, unsigned long addr)
326{
327	ep93xx_pata_write(drv_data, value, addr, false);
328}
329
330static void ep93xx_pata_set_piomode(struct ata_port *ap,
331				    struct ata_device *adev)
332{
333	struct ep93xx_pata_data *drv_data = ap->host->private_data;
334	struct ata_device *pair = ata_dev_pair(adev);
335	/*
336	 * Calculate timings for the delay loop, assuming ep93xx cpu speed
337	 * is 200MHz (maximum possible for ep93xx). If actual cpu speed is
338	 * slower, we will wait a bit longer in each delay.
339	 * Additional division of cpu speed by 5, because single iteration
340	 * of our delay loop takes 5 cpu cycles (25ns).
341	 */
342	unsigned long T = 1000000 / (200 / 5);
343
344	ata_timing_compute(adev, adev->pio_mode, &drv_data->t, T, 0);
345	if (pair && pair->pio_mode) {
346		struct ata_timing t;
347		ata_timing_compute(pair, pair->pio_mode, &t, T, 0);
348		ata_timing_merge(&t, &drv_data->t, &drv_data->t,
349			ATA_TIMING_SETUP | ATA_TIMING_8BIT);
350	}
351	drv_data->iordy = ata_pio_need_iordy(adev);
352
353	ep93xx_pata_enable_pio(drv_data->ide_base,
354			       adev->pio_mode - XFER_PIO_0);
355}
356
357/* Note: original code is ata_sff_check_status */
358static u8 ep93xx_pata_check_status(struct ata_port *ap)
359{
360	struct ep93xx_pata_data *drv_data = ap->host->private_data;
361
362	return ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_STATUS);
363}
364
365static u8 ep93xx_pata_check_altstatus(struct ata_port *ap)
366{
367	struct ep93xx_pata_data *drv_data = ap->host->private_data;
368
369	return ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_ALTSTATUS);
370}
371
372/* Note: original code is ata_sff_tf_load */
373static void ep93xx_pata_tf_load(struct ata_port *ap,
374				const struct ata_taskfile *tf)
375{
376	struct ep93xx_pata_data *drv_data = ap->host->private_data;
377	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
378
379	if (tf->ctl != ap->last_ctl) {
380		ep93xx_pata_write_reg(drv_data, tf->ctl, IDECTRL_ADDR_CTL);
381		ap->last_ctl = tf->ctl;
382		ata_wait_idle(ap);
383	}
384
385	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
386		ep93xx_pata_write_reg(drv_data, tf->hob_feature,
387			IDECTRL_ADDR_FEATURE);
388		ep93xx_pata_write_reg(drv_data, tf->hob_nsect,
389			IDECTRL_ADDR_NSECT);
390		ep93xx_pata_write_reg(drv_data, tf->hob_lbal,
391			IDECTRL_ADDR_LBAL);
392		ep93xx_pata_write_reg(drv_data, tf->hob_lbam,
393			IDECTRL_ADDR_LBAM);
394		ep93xx_pata_write_reg(drv_data, tf->hob_lbah,
395			IDECTRL_ADDR_LBAH);
396	}
397
398	if (is_addr) {
399		ep93xx_pata_write_reg(drv_data, tf->feature,
400			IDECTRL_ADDR_FEATURE);
401		ep93xx_pata_write_reg(drv_data, tf->nsect, IDECTRL_ADDR_NSECT);
402		ep93xx_pata_write_reg(drv_data, tf->lbal, IDECTRL_ADDR_LBAL);
403		ep93xx_pata_write_reg(drv_data, tf->lbam, IDECTRL_ADDR_LBAM);
404		ep93xx_pata_write_reg(drv_data, tf->lbah, IDECTRL_ADDR_LBAH);
405	}
406
407	if (tf->flags & ATA_TFLAG_DEVICE)
408		ep93xx_pata_write_reg(drv_data, tf->device,
409			IDECTRL_ADDR_DEVICE);
410
411	ata_wait_idle(ap);
412}
413
414/* Note: original code is ata_sff_tf_read */
415static void ep93xx_pata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
416{
417	struct ep93xx_pata_data *drv_data = ap->host->private_data;
418
419	tf->command = ep93xx_pata_check_status(ap);
420	tf->feature = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_FEATURE);
421	tf->nsect = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_NSECT);
422	tf->lbal = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAL);
423	tf->lbam = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAM);
424	tf->lbah = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAH);
425	tf->device = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_DEVICE);
426
427	if (tf->flags & ATA_TFLAG_LBA48) {
428		ep93xx_pata_write_reg(drv_data, tf->ctl | ATA_HOB,
429			IDECTRL_ADDR_CTL);
430		tf->hob_feature = ep93xx_pata_read_reg(drv_data,
431			IDECTRL_ADDR_FEATURE);
432		tf->hob_nsect = ep93xx_pata_read_reg(drv_data,
433			IDECTRL_ADDR_NSECT);
434		tf->hob_lbal = ep93xx_pata_read_reg(drv_data,
435			IDECTRL_ADDR_LBAL);
436		tf->hob_lbam = ep93xx_pata_read_reg(drv_data,
437			IDECTRL_ADDR_LBAM);
438		tf->hob_lbah = ep93xx_pata_read_reg(drv_data,
439			IDECTRL_ADDR_LBAH);
440		ep93xx_pata_write_reg(drv_data, tf->ctl, IDECTRL_ADDR_CTL);
441		ap->last_ctl = tf->ctl;
442	}
443}
444
445/* Note: original code is ata_sff_exec_command */
446static void ep93xx_pata_exec_command(struct ata_port *ap,
447				     const struct ata_taskfile *tf)
448{
449	struct ep93xx_pata_data *drv_data = ap->host->private_data;
450
451	ep93xx_pata_write_reg(drv_data, tf->command,
452			  IDECTRL_ADDR_COMMAND);
453	ata_sff_pause(ap);
454}
455
456/* Note: original code is ata_sff_dev_select */
457static void ep93xx_pata_dev_select(struct ata_port *ap, unsigned int device)
458{
459	struct ep93xx_pata_data *drv_data = ap->host->private_data;
460	u8 tmp = ATA_DEVICE_OBS;
461
462	if (device != 0)
463		tmp |= ATA_DEV1;
464
465	ep93xx_pata_write_reg(drv_data, tmp, IDECTRL_ADDR_DEVICE);
466	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
467}
468
469/* Note: original code is ata_sff_set_devctl */
470static void ep93xx_pata_set_devctl(struct ata_port *ap, u8 ctl)
471{
472	struct ep93xx_pata_data *drv_data = ap->host->private_data;
473
474	ep93xx_pata_write_reg(drv_data, ctl, IDECTRL_ADDR_CTL);
475}
476
477/* Note: original code is ata_sff_data_xfer */
478static unsigned int ep93xx_pata_data_xfer(struct ata_queued_cmd *qc,
479					  unsigned char *buf,
480					  unsigned int buflen, int rw)
481{
482	struct ata_port *ap = qc->dev->link->ap;
483	struct ep93xx_pata_data *drv_data = ap->host->private_data;
484	u16 *data = (u16 *)buf;
485	unsigned int words = buflen >> 1;
486
487	/* Transfer multiple of 2 bytes */
488	while (words--)
489		if (rw == READ)
490			*data++ = cpu_to_le16(
491				ep93xx_pata_read_data(
492					drv_data, IDECTRL_ADDR_DATA));
493		else
494			ep93xx_pata_write_data(drv_data, le16_to_cpu(*data++),
495				IDECTRL_ADDR_DATA);
496
497	/* Transfer trailing 1 byte, if any. */
498	if (unlikely(buflen & 0x01)) {
499		unsigned char pad[2] = { };
500
501		buf += buflen - 1;
502
503		if (rw == READ) {
504			*pad = cpu_to_le16(
505				ep93xx_pata_read_data(
506					drv_data, IDECTRL_ADDR_DATA));
507			*buf = pad[0];
508		} else {
509			pad[0] = *buf;
510			ep93xx_pata_write_data(drv_data, le16_to_cpu(*pad),
511					  IDECTRL_ADDR_DATA);
512		}
513		words++;
514	}
515
516	return words << 1;
517}
518
519/* Note: original code is ata_devchk */
520static bool ep93xx_pata_device_is_present(struct ata_port *ap,
521					  unsigned int device)
522{
523	struct ep93xx_pata_data *drv_data = ap->host->private_data;
524	u8 nsect, lbal;
525
526	ap->ops->sff_dev_select(ap, device);
527
528	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_NSECT);
529	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_LBAL);
530
531	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_NSECT);
532	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_LBAL);
533
534	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_NSECT);
535	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_LBAL);
536
537	nsect = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_NSECT);
538	lbal = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAL);
539
540	if ((nsect == 0x55) && (lbal == 0xaa))
541		return true;
542
543	return false;
544}
545
546/* Note: original code is ata_sff_wait_after_reset */
547static int ep93xx_pata_wait_after_reset(struct ata_link *link,
548					unsigned int devmask,
549					unsigned long deadline)
550{
551	struct ata_port *ap = link->ap;
552	struct ep93xx_pata_data *drv_data = ap->host->private_data;
553	unsigned int dev0 = devmask & (1 << 0);
554	unsigned int dev1 = devmask & (1 << 1);
555	int rc, ret = 0;
556
557	ata_msleep(ap, ATA_WAIT_AFTER_RESET);
558
559	/* always check readiness of the master device */
560	rc = ata_sff_wait_ready(link, deadline);
561	/*
562	 * -ENODEV means the odd clown forgot the D7 pulldown resistor
563	 * and TF status is 0xff, bail out on it too.
564	 */
565	if (rc)
566		return rc;
567
568	/*
569	 * if device 1 was found in ata_devchk, wait for register
570	 * access briefly, then wait for BSY to clear.
571	 */
572	if (dev1) {
573		int i;
574
575		ap->ops->sff_dev_select(ap, 1);
576
577		/*
578		 * Wait for register access.  Some ATAPI devices fail
579		 * to set nsect/lbal after reset, so don't waste too
580		 * much time on it.  We're gonna wait for !BSY anyway.
581		 */
582		for (i = 0; i < 2; i++) {
583			u8 nsect, lbal;
584
585			nsect = ep93xx_pata_read_reg(drv_data,
586				IDECTRL_ADDR_NSECT);
587			lbal = ep93xx_pata_read_reg(drv_data,
588				IDECTRL_ADDR_LBAL);
589			if (nsect == 1 && lbal == 1)
590				break;
591			msleep(50);	/* give drive a breather */
592		}
593
594		rc = ata_sff_wait_ready(link, deadline);
595		if (rc) {
596			if (rc != -ENODEV)
597				return rc;
598			ret = rc;
599		}
600	}
601	/* is all this really necessary? */
602	ap->ops->sff_dev_select(ap, 0);
603	if (dev1)
604		ap->ops->sff_dev_select(ap, 1);
605	if (dev0)
606		ap->ops->sff_dev_select(ap, 0);
607
608	return ret;
609}
610
611/* Note: original code is ata_bus_softreset */
612static int ep93xx_pata_bus_softreset(struct ata_port *ap, unsigned int devmask,
613				     unsigned long deadline)
614{
615	struct ep93xx_pata_data *drv_data = ap->host->private_data;
616
617	ep93xx_pata_write_reg(drv_data, ap->ctl, IDECTRL_ADDR_CTL);
618	udelay(20);		/* FIXME: flush */
619	ep93xx_pata_write_reg(drv_data, ap->ctl | ATA_SRST, IDECTRL_ADDR_CTL);
620	udelay(20);		/* FIXME: flush */
621	ep93xx_pata_write_reg(drv_data, ap->ctl, IDECTRL_ADDR_CTL);
622	ap->last_ctl = ap->ctl;
623
624	return ep93xx_pata_wait_after_reset(&ap->link, devmask, deadline);
625}
626
627static void ep93xx_pata_release_dma(struct ep93xx_pata_data *drv_data)
628{
629	if (drv_data->dma_rx_channel) {
630		dma_release_channel(drv_data->dma_rx_channel);
631		drv_data->dma_rx_channel = NULL;
632	}
633	if (drv_data->dma_tx_channel) {
634		dma_release_channel(drv_data->dma_tx_channel);
635		drv_data->dma_tx_channel = NULL;
636	}
637}
638
639static bool ep93xx_pata_dma_filter(struct dma_chan *chan, void *filter_param)
640{
641	if (ep93xx_dma_chan_is_m2p(chan))
642		return false;
643
644	chan->private = filter_param;
645	return true;
646}
647
648static void ep93xx_pata_dma_init(struct ep93xx_pata_data *drv_data)
649{
650	const struct platform_device *pdev = drv_data->pdev;
651	dma_cap_mask_t mask;
652	struct dma_slave_config conf;
653
654	dma_cap_zero(mask);
655	dma_cap_set(DMA_SLAVE, mask);
656
657	/*
658	 * Request two channels for IDE. Another possibility would be
659	 * to request only one channel, and reprogram it's direction at
660	 * start of new transfer.
661	 */
662	drv_data->dma_rx_data.port = EP93XX_DMA_IDE;
663	drv_data->dma_rx_data.direction = DMA_DEV_TO_MEM;
664	drv_data->dma_rx_data.name = "ep93xx-pata-rx";
665	drv_data->dma_rx_channel = dma_request_channel(mask,
666		ep93xx_pata_dma_filter, &drv_data->dma_rx_data);
667	if (!drv_data->dma_rx_channel)
668		return;
669
670	drv_data->dma_tx_data.port = EP93XX_DMA_IDE;
671	drv_data->dma_tx_data.direction = DMA_MEM_TO_DEV;
672	drv_data->dma_tx_data.name = "ep93xx-pata-tx";
673	drv_data->dma_tx_channel = dma_request_channel(mask,
674		ep93xx_pata_dma_filter, &drv_data->dma_tx_data);
675	if (!drv_data->dma_tx_channel) {
676		dma_release_channel(drv_data->dma_rx_channel);
677		return;
678	}
679
680	/* Configure receive channel direction and source address */
681	memset(&conf, 0, sizeof(conf));
682	conf.direction = DMA_DEV_TO_MEM;
683	conf.src_addr = drv_data->udma_in_phys;
684	conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
685	if (dmaengine_slave_config(drv_data->dma_rx_channel, &conf)) {
686		dev_err(&pdev->dev, "failed to configure rx dma channel\n");
687		ep93xx_pata_release_dma(drv_data);
688		return;
689	}
690
691	/* Configure transmit channel direction and destination address */
692	memset(&conf, 0, sizeof(conf));
693	conf.direction = DMA_MEM_TO_DEV;
694	conf.dst_addr = drv_data->udma_out_phys;
695	conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
696	if (dmaengine_slave_config(drv_data->dma_tx_channel, &conf)) {
697		dev_err(&pdev->dev, "failed to configure tx dma channel\n");
698		ep93xx_pata_release_dma(drv_data);
699	}
700}
701
702static void ep93xx_pata_dma_start(struct ata_queued_cmd *qc)
703{
704	struct dma_async_tx_descriptor *txd;
705	struct ep93xx_pata_data *drv_data = qc->ap->host->private_data;
706	void __iomem *base = drv_data->ide_base;
707	struct ata_device *adev = qc->dev;
708	u32 v = qc->dma_dir == DMA_TO_DEVICE ? IDEUDMAOP_RWOP : 0;
709	struct dma_chan *channel = qc->dma_dir == DMA_TO_DEVICE
710		? drv_data->dma_tx_channel : drv_data->dma_rx_channel;
711
712	txd = dmaengine_prep_slave_sg(channel, qc->sg, qc->n_elem, qc->dma_dir,
713		DMA_CTRL_ACK);
714	if (!txd) {
715		dev_err(qc->ap->dev, "failed to prepare slave for sg dma\n");
716		return;
717	}
718	txd->callback = NULL;
719	txd->callback_param = NULL;
720
721	if (dmaengine_submit(txd) < 0) {
722		dev_err(qc->ap->dev, "failed to submit dma transfer\n");
723		return;
724	}
725	dma_async_issue_pending(channel);
726
727	/*
728	 * When enabling UDMA operation, IDEUDMAOP register needs to be
729	 * programmed in three step sequence:
730	 * 1) set or clear the RWOP bit,
731	 * 2) perform dummy read of the register,
732	 * 3) set the UEN bit.
733	 */
734	writel(v, base + IDEUDMAOP);
735	readl(base + IDEUDMAOP);
736	writel(v | IDEUDMAOP_UEN, base + IDEUDMAOP);
737
738	writel(IDECFG_IDEEN | IDECFG_UDMA |
739		((adev->xfer_mode - XFER_UDMA_0) << IDECFG_MODE_SHIFT),
740		base + IDECFG);
741}
742
743static void ep93xx_pata_dma_stop(struct ata_queued_cmd *qc)
744{
745	struct ep93xx_pata_data *drv_data = qc->ap->host->private_data;
746	void __iomem *base = drv_data->ide_base;
747
748	/* terminate all dma transfers, if not yet finished */
749	dmaengine_terminate_all(drv_data->dma_rx_channel);
750	dmaengine_terminate_all(drv_data->dma_tx_channel);
751
752	/*
753	 * To properly stop IDE-DMA, IDEUDMAOP register must to be cleared
754	 * and IDECTRL register must be set to default value.
755	 */
756	writel(0, base + IDEUDMAOP);
757	writel(readl(base + IDECTRL) | IDECTRL_DIOWN | IDECTRL_DIORN |
758		IDECTRL_CS0N | IDECTRL_CS1N, base + IDECTRL);
759
760	ep93xx_pata_enable_pio(drv_data->ide_base,
761		qc->dev->pio_mode - XFER_PIO_0);
762
763	ata_sff_dma_pause(qc->ap);
764}
765
766static void ep93xx_pata_dma_setup(struct ata_queued_cmd *qc)
767{
768	qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
769}
770
771static u8 ep93xx_pata_dma_status(struct ata_port *ap)
772{
773	struct ep93xx_pata_data *drv_data = ap->host->private_data;
774	u32 val = readl(drv_data->ide_base + IDEUDMASTS);
775
776	/*
777	 * UDMA Status Register bits:
778	 *
779	 * DMAIDE - DMA request signal from UDMA state machine,
780	 * INTIDE - INT line generated by UDMA because of errors in the
781	 *          state machine,
782	 * SBUSY - UDMA state machine busy, not in idle state,
783	 * NDO   - error for data-out not completed,
784	 * NDI   - error for data-in not completed,
785	 * N4X   - error for data transferred not multiplies of four
786	 *         32-bit words.
787	 * (EP93xx UG p27-17)
788	 */
789	if (val & IDEUDMASTS_NDO || val & IDEUDMASTS_NDI ||
790	    val & IDEUDMASTS_N4X || val & IDEUDMASTS_INTIDE)
791		return ATA_DMA_ERR;
792
793	/* read INTRQ (INT[3]) pin input state */
794	if (readl(drv_data->ide_base + IDECTRL) & IDECTRL_INTRQ)
795		return ATA_DMA_INTR;
796
797	if (val & IDEUDMASTS_SBUSY || val & IDEUDMASTS_DMAIDE)
798		return ATA_DMA_ACTIVE;
799
800	return 0;
801}
802
803/* Note: original code is ata_sff_softreset */
804static int ep93xx_pata_softreset(struct ata_link *al, unsigned int *classes,
805				 unsigned long deadline)
806{
807	struct ata_port *ap = al->ap;
808	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
809	unsigned int devmask = 0;
810	int rc;
811	u8 err;
812
813	/* determine if device 0/1 are present */
814	if (ep93xx_pata_device_is_present(ap, 0))
815		devmask |= (1 << 0);
816	if (slave_possible && ep93xx_pata_device_is_present(ap, 1))
817		devmask |= (1 << 1);
818
819	/* select device 0 again */
820	ap->ops->sff_dev_select(al->ap, 0);
821
822	/* issue bus reset */
823	rc = ep93xx_pata_bus_softreset(ap, devmask, deadline);
824	/* if link is ocuppied, -ENODEV too is an error */
825	if (rc && (rc != -ENODEV || sata_scr_valid(al))) {
826		ata_link_err(al, "SRST failed (errno=%d)\n", rc);
827		return rc;
828	}
829
830	/* determine by signature whether we have ATA or ATAPI devices */
831	classes[0] = ata_sff_dev_classify(&al->device[0], devmask & (1 << 0),
832					  &err);
833	if (slave_possible && err != 0x81)
834		classes[1] = ata_sff_dev_classify(&al->device[1],
835						  devmask & (1 << 1), &err);
836
837	return 0;
838}
839
840/* Note: original code is ata_sff_drain_fifo */
841static void ep93xx_pata_drain_fifo(struct ata_queued_cmd *qc)
842{
843	int count;
844	struct ata_port *ap;
845	struct ep93xx_pata_data *drv_data;
846
847	/* We only need to flush incoming data when a command was running */
848	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
849		return;
850
851	ap = qc->ap;
852	drv_data = ap->host->private_data;
853	/* Drain up to 64K of data before we give up this recovery method */
854	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
855		     && count < 65536; count += 2)
856		ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_DATA);
857
858	/* Can become DEBUG later */
859	if (count)
860		ata_port_dbg(ap, "drained %d bytes to clear DRQ.\n", count);
861
862}
863
864static int ep93xx_pata_port_start(struct ata_port *ap)
865{
866	struct ep93xx_pata_data *drv_data = ap->host->private_data;
867
868	/*
869	 * Set timings to safe values at startup (= number of ns from ATA
870	 * specification), we'll switch to properly calculated values later.
871	 */
872	drv_data->t = *ata_timing_find_mode(XFER_PIO_0);
873	return 0;
874}
875
876static struct scsi_host_template ep93xx_pata_sht = {
877	ATA_BASE_SHT(DRV_NAME),
878	/* ep93xx dma implementation limit */
879	.sg_tablesize		= 32,
880	/* ep93xx dma can't transfer 65536 bytes at once */
881	.dma_boundary		= 0x7fff,
882};
883
884static struct ata_port_operations ep93xx_pata_port_ops = {
885	.inherits		= &ata_bmdma_port_ops,
886
887	.qc_prep		= ata_noop_qc_prep,
888
889	.softreset		= ep93xx_pata_softreset,
890	.hardreset		= ATA_OP_NULL,
891
892	.sff_dev_select		= ep93xx_pata_dev_select,
893	.sff_set_devctl		= ep93xx_pata_set_devctl,
894	.sff_check_status	= ep93xx_pata_check_status,
895	.sff_check_altstatus	= ep93xx_pata_check_altstatus,
896	.sff_tf_load		= ep93xx_pata_tf_load,
897	.sff_tf_read		= ep93xx_pata_tf_read,
898	.sff_exec_command	= ep93xx_pata_exec_command,
899	.sff_data_xfer		= ep93xx_pata_data_xfer,
900	.sff_drain_fifo		= ep93xx_pata_drain_fifo,
901	.sff_irq_clear		= ATA_OP_NULL,
902
903	.set_piomode		= ep93xx_pata_set_piomode,
904
905	.bmdma_setup		= ep93xx_pata_dma_setup,
906	.bmdma_start		= ep93xx_pata_dma_start,
907	.bmdma_stop		= ep93xx_pata_dma_stop,
908	.bmdma_status		= ep93xx_pata_dma_status,
909
910	.cable_detect		= ata_cable_unknown,
911	.port_start		= ep93xx_pata_port_start,
912};
913
914static int ep93xx_pata_probe(struct platform_device *pdev)
915{
916	struct ep93xx_pata_data *drv_data;
917	struct ata_host *host;
918	struct ata_port *ap;
919	int irq;
920	struct resource *mem_res;
921	void __iomem *ide_base;
922	int err;
923
924	err = ep93xx_ide_acquire_gpio(pdev);
925	if (err)
926		return err;
927
928	/* INT[3] (IRQ_EP93XX_EXT3) line connected as pull down */
929	irq = platform_get_irq(pdev, 0);
930	if (irq < 0) {
931		err = irq;
932		goto err_rel_gpio;
933	}
934
935	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
936	ide_base = devm_ioremap_resource(&pdev->dev, mem_res);
937	if (IS_ERR(ide_base)) {
938		err = PTR_ERR(ide_base);
939		goto err_rel_gpio;
940	}
941
942	drv_data = devm_kzalloc(&pdev->dev, sizeof(*drv_data), GFP_KERNEL);
943	if (!drv_data) {
944		err = -ENXIO;
945		goto err_rel_gpio;
946	}
947
948	drv_data->pdev = pdev;
949	drv_data->ide_base = ide_base;
950	drv_data->udma_in_phys = mem_res->start + IDEUDMADATAIN;
951	drv_data->udma_out_phys = mem_res->start + IDEUDMADATAOUT;
952	ep93xx_pata_dma_init(drv_data);
953
954	/* allocate host */
955	host = ata_host_alloc(&pdev->dev, 1);
956	if (!host) {
957		err = -ENXIO;
958		goto err_rel_dma;
959	}
960
961	ep93xx_pata_clear_regs(ide_base);
962
963	host->private_data = drv_data;
964
965	ap = host->ports[0];
966	ap->dev = &pdev->dev;
967	ap->ops = &ep93xx_pata_port_ops;
968	ap->flags |= ATA_FLAG_SLAVE_POSS;
969	ap->pio_mask = ATA_PIO4;
970
971	/*
972	 * Maximum UDMA modes:
973	 * EP931x rev.E0 - UDMA2
974	 * EP931x rev.E1 - UDMA3
975	 * EP931x rev.E2 - UDMA4
976	 *
977	 * MWDMA support was removed from EP931x rev.E2,
978	 * so this driver supports only UDMA modes.
979	 */
980	if (drv_data->dma_rx_channel && drv_data->dma_tx_channel) {
981		int chip_rev = ep93xx_chip_revision();
982
983		if (chip_rev == EP93XX_CHIP_REV_E1)
984			ap->udma_mask = ATA_UDMA3;
985		else if (chip_rev == EP93XX_CHIP_REV_E2)
986			ap->udma_mask = ATA_UDMA4;
987		else
988			ap->udma_mask = ATA_UDMA2;
989	}
990
991	/* defaults, pio 0 */
992	ep93xx_pata_enable_pio(ide_base, 0);
993
994	dev_info(&pdev->dev, "version " DRV_VERSION "\n");
995
996	/* activate host */
997	err = ata_host_activate(host, irq, ata_bmdma_interrupt, 0,
998		&ep93xx_pata_sht);
999	if (err == 0)
1000		return 0;
1001
1002err_rel_dma:
1003	ep93xx_pata_release_dma(drv_data);
1004err_rel_gpio:
1005	ep93xx_ide_release_gpio(pdev);
1006	return err;
1007}
1008
1009static int ep93xx_pata_remove(struct platform_device *pdev)
1010{
1011	struct ata_host *host = platform_get_drvdata(pdev);
1012	struct ep93xx_pata_data *drv_data = host->private_data;
1013
1014	ata_host_detach(host);
1015	ep93xx_pata_release_dma(drv_data);
1016	ep93xx_pata_clear_regs(drv_data->ide_base);
1017	ep93xx_ide_release_gpio(pdev);
1018	return 0;
1019}
1020
1021static struct platform_driver ep93xx_pata_platform_driver = {
1022	.driver = {
1023		.name = DRV_NAME,
1024	},
1025	.probe = ep93xx_pata_probe,
1026	.remove = ep93xx_pata_remove,
1027};
1028
1029module_platform_driver(ep93xx_pata_platform_driver);
1030
1031MODULE_AUTHOR("Alessandro Zummo, Lennert Buytenhek, Joao Ramos, "
1032		"Bartlomiej Zolnierkiewicz, Rafal Prylowski");
1033MODULE_DESCRIPTION("low-level driver for cirrus ep93xx IDE controller");
1034MODULE_LICENSE("GPL");
1035MODULE_VERSION(DRV_VERSION);
1036MODULE_ALIAS("platform:pata_ep93xx");
1037