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