xref: /linux/drivers/ata/pata_ep93xx.c (revision fab183d632628381b466a41479489541ac0e29a0)
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/sys_soc.h>
44 #include <linux/delay.h>
45 #include <linux/dmaengine.h>
46 #include <linux/ktime.h>
47 
48 #include <linux/soc/cirrus/ep93xx.h>
49 
50 #define DRV_NAME	"ep93xx-ide"
51 #define DRV_VERSION	"1.0"
52 
53 enum {
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 
127 struct ep93xx_pata_data {
128 	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 dma_chan *dma_tx_channel;
138 };
139 
ep93xx_pata_clear_regs(void __iomem * base)140 static void ep93xx_pata_clear_regs(void __iomem *base)
141 {
142 	writel(IDECTRL_CS0N | IDECTRL_CS1N | IDECTRL_DIORN |
143 		IDECTRL_DIOWN, base + IDECTRL);
144 
145 	writel(0, base + IDECFG);
146 	writel(0, base + IDEMDMAOP);
147 	writel(0, base + IDEUDMAOP);
148 	writel(0, base + IDEDATAOUT);
149 	writel(0, base + IDEDATAIN);
150 	writel(0, base + IDEMDMADATAOUT);
151 	writel(0, base + IDEMDMADATAIN);
152 	writel(0, base + IDEUDMADATAOUT);
153 	writel(0, base + IDEUDMADATAIN);
154 	writel(0, base + IDEUDMADEBUG);
155 }
156 
ep93xx_pata_check_iordy(void __iomem * base)157 static bool ep93xx_pata_check_iordy(void __iomem *base)
158 {
159 	return !!(readl(base + IDECTRL) & IDECTRL_IORDY);
160 }
161 
162 /*
163  * According to EP93xx User's Guide, WST field of IDECFG specifies number
164  * of HCLK cycles to hold the data bus after a PIO write operation.
165  * It should be programmed to guarantee following delays:
166  *
167  * PIO Mode   [ns]
168  * 0          30
169  * 1          20
170  * 2          15
171  * 3          10
172  * 4          5
173  *
174  * Maximum possible value for HCLK is 100MHz.
175  */
ep93xx_pata_get_wst(int pio_mode)176 static int ep93xx_pata_get_wst(int pio_mode)
177 {
178 	int val;
179 
180 	if (pio_mode == 0)
181 		val = 3;
182 	else if (pio_mode < 3)
183 		val = 2;
184 	else
185 		val = 1;
186 
187 	return val << IDECFG_WST_SHIFT;
188 }
189 
ep93xx_pata_enable_pio(void __iomem * base,int pio_mode)190 static void ep93xx_pata_enable_pio(void __iomem *base, int pio_mode)
191 {
192 	writel(IDECFG_IDEEN | IDECFG_PIO |
193 		ep93xx_pata_get_wst(pio_mode) |
194 		(pio_mode << IDECFG_MODE_SHIFT), base + IDECFG);
195 }
196 
197 /*
198  * Based on delay loop found in mach-pxa/mp900.c.
199  *
200  * Single iteration should take 5 cpu cycles. This is 25ns assuming the
201  * fastest ep93xx cpu speed (200MHz) and is better optimized for PIO4 timings
202  * than eg. 20ns.
203  */
ep93xx_pata_delay(unsigned long count)204 static void ep93xx_pata_delay(unsigned long count)
205 {
206 #ifdef CONFIG_ARM
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 #else
216 	while (count--)
217 		cpu_relax();
218 #endif
219 }
220 
ep93xx_pata_wait_for_iordy(void __iomem * base,unsigned long t2)221 static unsigned long ep93xx_pata_wait_for_iordy(void __iomem *base,
222 						unsigned long t2)
223 {
224 	/*
225 	 * According to ATA specification, IORDY pin can be first sampled
226 	 * tA = 35ns after activation of DIOR-/DIOW-. Maximum IORDY pulse
227 	 * width is tB = 1250ns.
228 	 *
229 	 * We are already t2 delay loop iterations after activation of
230 	 * DIOR-/DIOW-, so we set timeout to (1250 + 35) / 25 - t2 additional
231 	 * delay loop iterations.
232 	 */
233 	unsigned long start = (1250 + 35) / 25 - t2;
234 	unsigned long counter = start;
235 
236 	while (!ep93xx_pata_check_iordy(base) && counter--)
237 		ep93xx_pata_delay(1);
238 	return start - counter;
239 }
240 
241 /* common part at start of ep93xx_pata_read/write() */
ep93xx_pata_rw_begin(void __iomem * base,unsigned long addr,unsigned long t1)242 static void ep93xx_pata_rw_begin(void __iomem *base, unsigned long addr,
243 				 unsigned long t1)
244 {
245 	writel(IDECTRL_DIOWN | IDECTRL_DIORN | addr, base + IDECTRL);
246 	ep93xx_pata_delay(t1);
247 }
248 
249 /* common part at end of ep93xx_pata_read/write() */
ep93xx_pata_rw_end(void __iomem * base,unsigned long addr,bool iordy,unsigned long t0,unsigned long t2,unsigned long t2i)250 static void ep93xx_pata_rw_end(void __iomem *base, unsigned long addr,
251 			       bool iordy, unsigned long t0, unsigned long t2,
252 			       unsigned long t2i)
253 {
254 	ep93xx_pata_delay(t2);
255 	/* lengthen t2 if needed */
256 	if (iordy)
257 		t2 += ep93xx_pata_wait_for_iordy(base, t2);
258 	writel(IDECTRL_DIOWN | IDECTRL_DIORN | addr, base + IDECTRL);
259 	if (t0 > t2 && t0 - t2 > t2i)
260 		ep93xx_pata_delay(t0 - t2);
261 	else
262 		ep93xx_pata_delay(t2i);
263 }
264 
ep93xx_pata_read(struct ep93xx_pata_data * drv_data,unsigned long addr,bool reg)265 static u16 ep93xx_pata_read(struct ep93xx_pata_data *drv_data,
266 			    unsigned long addr,
267 			    bool reg)
268 {
269 	void __iomem *base = drv_data->ide_base;
270 	const struct ata_timing *t = &drv_data->t;
271 	unsigned long t0 = reg ? t->cyc8b : t->cycle;
272 	unsigned long t2 = reg ? t->act8b : t->active;
273 	unsigned long t2i = reg ? t->rec8b : t->recover;
274 
275 	ep93xx_pata_rw_begin(base, addr, t->setup);
276 	writel(IDECTRL_DIOWN | addr, base + IDECTRL);
277 	/*
278 	 * The IDEDATAIN register is loaded from the DD pins at the positive
279 	 * edge of the DIORN signal. (EP93xx UG p27-14)
280 	 */
281 	ep93xx_pata_rw_end(base, addr, drv_data->iordy, t0, t2, t2i);
282 	return readl(base + IDEDATAIN);
283 }
284 
285 /* IDE register read */
ep93xx_pata_read_reg(struct ep93xx_pata_data * drv_data,unsigned long addr)286 static u16 ep93xx_pata_read_reg(struct ep93xx_pata_data *drv_data,
287 				unsigned long addr)
288 {
289 	return ep93xx_pata_read(drv_data, addr, true);
290 }
291 
292 /* PIO data read */
ep93xx_pata_read_data(struct ep93xx_pata_data * drv_data,unsigned long addr)293 static u16 ep93xx_pata_read_data(struct ep93xx_pata_data *drv_data,
294 				 unsigned long addr)
295 {
296 	return ep93xx_pata_read(drv_data, addr, false);
297 }
298 
ep93xx_pata_write(struct ep93xx_pata_data * drv_data,u16 value,unsigned long addr,bool reg)299 static void ep93xx_pata_write(struct ep93xx_pata_data *drv_data,
300 			      u16 value, unsigned long addr,
301 			      bool reg)
302 {
303 	void __iomem *base = drv_data->ide_base;
304 	const struct ata_timing *t = &drv_data->t;
305 	unsigned long t0 = reg ? t->cyc8b : t->cycle;
306 	unsigned long t2 = reg ? t->act8b : t->active;
307 	unsigned long t2i = reg ? t->rec8b : t->recover;
308 
309 	ep93xx_pata_rw_begin(base, addr, t->setup);
310 	/*
311 	 * Value from IDEDATAOUT register is driven onto the DD pins when
312 	 * DIOWN is low. (EP93xx UG p27-13)
313 	 */
314 	writel(value, base + IDEDATAOUT);
315 	writel(IDECTRL_DIORN | addr, base + IDECTRL);
316 	ep93xx_pata_rw_end(base, addr, drv_data->iordy, t0, t2, t2i);
317 }
318 
319 /* IDE register write */
ep93xx_pata_write_reg(struct ep93xx_pata_data * drv_data,u16 value,unsigned long addr)320 static void ep93xx_pata_write_reg(struct ep93xx_pata_data *drv_data,
321 				  u16 value, unsigned long addr)
322 {
323 	ep93xx_pata_write(drv_data, value, addr, true);
324 }
325 
326 /* PIO data write */
ep93xx_pata_write_data(struct ep93xx_pata_data * drv_data,u16 value,unsigned long addr)327 static void ep93xx_pata_write_data(struct ep93xx_pata_data *drv_data,
328 				   u16 value, unsigned long addr)
329 {
330 	ep93xx_pata_write(drv_data, value, addr, false);
331 }
332 
ep93xx_pata_set_piomode(struct ata_port * ap,struct ata_device * adev)333 static void ep93xx_pata_set_piomode(struct ata_port *ap,
334 				    struct ata_device *adev)
335 {
336 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
337 	struct ata_device *pair = ata_dev_pair(adev);
338 	/*
339 	 * Calculate timings for the delay loop, assuming ep93xx cpu speed
340 	 * is 200MHz (maximum possible for ep93xx). If actual cpu speed is
341 	 * slower, we will wait a bit longer in each delay.
342 	 * Additional division of cpu speed by 5, because single iteration
343 	 * of our delay loop takes 5 cpu cycles (25ns).
344 	 */
345 	unsigned long T = 1000000 / (200 / 5);
346 
347 	ata_timing_compute(adev, adev->pio_mode, &drv_data->t, T, 0);
348 	if (pair && pair->pio_mode) {
349 		struct ata_timing t;
350 		ata_timing_compute(pair, pair->pio_mode, &t, T, 0);
351 		ata_timing_merge(&t, &drv_data->t, &drv_data->t,
352 			ATA_TIMING_SETUP | ATA_TIMING_8BIT);
353 	}
354 	drv_data->iordy = ata_pio_need_iordy(adev);
355 
356 	ep93xx_pata_enable_pio(drv_data->ide_base,
357 			       adev->pio_mode - XFER_PIO_0);
358 }
359 
360 /* Note: original code is ata_sff_check_status */
ep93xx_pata_check_status(struct ata_port * ap)361 static u8 ep93xx_pata_check_status(struct ata_port *ap)
362 {
363 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
364 
365 	return ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_STATUS);
366 }
367 
ep93xx_pata_check_altstatus(struct ata_port * ap)368 static u8 ep93xx_pata_check_altstatus(struct ata_port *ap)
369 {
370 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
371 
372 	return ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_ALTSTATUS);
373 }
374 
375 /* Note: original code is ata_sff_tf_load */
ep93xx_pata_tf_load(struct ata_port * ap,const struct ata_taskfile * tf)376 static void ep93xx_pata_tf_load(struct ata_port *ap,
377 				const struct ata_taskfile *tf)
378 {
379 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
380 	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
381 
382 	if (tf->ctl != ap->last_ctl) {
383 		ep93xx_pata_write_reg(drv_data, tf->ctl, IDECTRL_ADDR_CTL);
384 		ap->last_ctl = tf->ctl;
385 		ata_wait_idle(ap);
386 	}
387 
388 	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
389 		ep93xx_pata_write_reg(drv_data, tf->hob_feature,
390 			IDECTRL_ADDR_FEATURE);
391 		ep93xx_pata_write_reg(drv_data, tf->hob_nsect,
392 			IDECTRL_ADDR_NSECT);
393 		ep93xx_pata_write_reg(drv_data, tf->hob_lbal,
394 			IDECTRL_ADDR_LBAL);
395 		ep93xx_pata_write_reg(drv_data, tf->hob_lbam,
396 			IDECTRL_ADDR_LBAM);
397 		ep93xx_pata_write_reg(drv_data, tf->hob_lbah,
398 			IDECTRL_ADDR_LBAH);
399 	}
400 
401 	if (is_addr) {
402 		ep93xx_pata_write_reg(drv_data, tf->feature,
403 			IDECTRL_ADDR_FEATURE);
404 		ep93xx_pata_write_reg(drv_data, tf->nsect, IDECTRL_ADDR_NSECT);
405 		ep93xx_pata_write_reg(drv_data, tf->lbal, IDECTRL_ADDR_LBAL);
406 		ep93xx_pata_write_reg(drv_data, tf->lbam, IDECTRL_ADDR_LBAM);
407 		ep93xx_pata_write_reg(drv_data, tf->lbah, IDECTRL_ADDR_LBAH);
408 	}
409 
410 	if (tf->flags & ATA_TFLAG_DEVICE)
411 		ep93xx_pata_write_reg(drv_data, tf->device,
412 			IDECTRL_ADDR_DEVICE);
413 
414 	ata_wait_idle(ap);
415 }
416 
417 /* Note: original code is ata_sff_tf_read */
ep93xx_pata_tf_read(struct ata_port * ap,struct ata_taskfile * tf)418 static void ep93xx_pata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
419 {
420 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
421 
422 	tf->status = ep93xx_pata_check_status(ap);
423 	tf->error = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_FEATURE);
424 	tf->nsect = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_NSECT);
425 	tf->lbal = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAL);
426 	tf->lbam = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAM);
427 	tf->lbah = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAH);
428 	tf->device = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_DEVICE);
429 
430 	if (tf->flags & ATA_TFLAG_LBA48) {
431 		ep93xx_pata_write_reg(drv_data, tf->ctl | ATA_HOB,
432 			IDECTRL_ADDR_CTL);
433 		tf->hob_feature = ep93xx_pata_read_reg(drv_data,
434 			IDECTRL_ADDR_FEATURE);
435 		tf->hob_nsect = ep93xx_pata_read_reg(drv_data,
436 			IDECTRL_ADDR_NSECT);
437 		tf->hob_lbal = ep93xx_pata_read_reg(drv_data,
438 			IDECTRL_ADDR_LBAL);
439 		tf->hob_lbam = ep93xx_pata_read_reg(drv_data,
440 			IDECTRL_ADDR_LBAM);
441 		tf->hob_lbah = ep93xx_pata_read_reg(drv_data,
442 			IDECTRL_ADDR_LBAH);
443 		ep93xx_pata_write_reg(drv_data, tf->ctl, IDECTRL_ADDR_CTL);
444 		ap->last_ctl = tf->ctl;
445 	}
446 }
447 
448 /* Note: original code is ata_sff_exec_command */
ep93xx_pata_exec_command(struct ata_port * ap,const struct ata_taskfile * tf)449 static void ep93xx_pata_exec_command(struct ata_port *ap,
450 				     const struct ata_taskfile *tf)
451 {
452 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
453 
454 	ep93xx_pata_write_reg(drv_data, tf->command,
455 			  IDECTRL_ADDR_COMMAND);
456 	ata_sff_pause(ap);
457 }
458 
459 /* Note: original code is ata_sff_dev_select */
ep93xx_pata_dev_select(struct ata_port * ap,unsigned int device)460 static void ep93xx_pata_dev_select(struct ata_port *ap, unsigned int device)
461 {
462 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
463 	u8 tmp = ATA_DEVICE_OBS;
464 
465 	if (device != 0)
466 		tmp |= ATA_DEV1;
467 
468 	ep93xx_pata_write_reg(drv_data, tmp, IDECTRL_ADDR_DEVICE);
469 	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
470 }
471 
472 /* Note: original code is ata_sff_set_devctl */
ep93xx_pata_set_devctl(struct ata_port * ap,u8 ctl)473 static void ep93xx_pata_set_devctl(struct ata_port *ap, u8 ctl)
474 {
475 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
476 
477 	ep93xx_pata_write_reg(drv_data, ctl, IDECTRL_ADDR_CTL);
478 }
479 
480 /* Note: original code is ata_sff_data_xfer */
ep93xx_pata_data_xfer(struct ata_queued_cmd * qc,unsigned char * buf,unsigned int buflen,int rw)481 static unsigned int ep93xx_pata_data_xfer(struct ata_queued_cmd *qc,
482 					  unsigned char *buf,
483 					  unsigned int buflen, int rw)
484 {
485 	struct ata_port *ap = qc->dev->link->ap;
486 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
487 	u16 *data = (u16 *)buf;
488 	unsigned int words = buflen >> 1;
489 
490 	/* Transfer multiple of 2 bytes */
491 	while (words--)
492 		if (rw == READ)
493 			*data++ = cpu_to_le16(
494 				ep93xx_pata_read_data(
495 					drv_data, IDECTRL_ADDR_DATA));
496 		else
497 			ep93xx_pata_write_data(drv_data, le16_to_cpu(*data++),
498 				IDECTRL_ADDR_DATA);
499 
500 	/* Transfer trailing 1 byte, if any. */
501 	if (unlikely(buflen & 0x01)) {
502 		unsigned char pad[2] = { };
503 
504 		buf += buflen - 1;
505 
506 		if (rw == READ) {
507 			*pad = cpu_to_le16(
508 				ep93xx_pata_read_data(
509 					drv_data, IDECTRL_ADDR_DATA));
510 			*buf = pad[0];
511 		} else {
512 			pad[0] = *buf;
513 			ep93xx_pata_write_data(drv_data, le16_to_cpu(*pad),
514 					  IDECTRL_ADDR_DATA);
515 		}
516 		words++;
517 	}
518 
519 	return words << 1;
520 }
521 
522 /* Note: original code is ata_devchk */
ep93xx_pata_device_is_present(struct ata_port * ap,unsigned int device)523 static bool ep93xx_pata_device_is_present(struct ata_port *ap,
524 					  unsigned int device)
525 {
526 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
527 	u8 nsect, lbal;
528 
529 	ap->ops->sff_dev_select(ap, device);
530 
531 	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_NSECT);
532 	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_LBAL);
533 
534 	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_NSECT);
535 	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_LBAL);
536 
537 	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_NSECT);
538 	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_LBAL);
539 
540 	nsect = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_NSECT);
541 	lbal = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAL);
542 
543 	if ((nsect == 0x55) && (lbal == 0xaa))
544 		return true;
545 
546 	return false;
547 }
548 
549 /* Note: original code is ata_sff_wait_after_reset */
ep93xx_pata_wait_after_reset(struct ata_link * link,unsigned int devmask,unsigned long deadline)550 static int ep93xx_pata_wait_after_reset(struct ata_link *link,
551 					unsigned int devmask,
552 					unsigned long deadline)
553 {
554 	struct ata_port *ap = link->ap;
555 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
556 	unsigned int dev0 = devmask & (1 << 0);
557 	unsigned int dev1 = devmask & (1 << 1);
558 	int rc, ret = 0;
559 
560 	ata_msleep(ap, ATA_WAIT_AFTER_RESET);
561 
562 	/* always check readiness of the master device */
563 	rc = ata_sff_wait_ready(link, deadline);
564 	/*
565 	 * -ENODEV means the odd clown forgot the D7 pulldown resistor
566 	 * and TF status is 0xff, bail out on it too.
567 	 */
568 	if (rc)
569 		return rc;
570 
571 	/*
572 	 * if device 1 was found in ata_devchk, wait for register
573 	 * access briefly, then wait for BSY to clear.
574 	 */
575 	if (dev1) {
576 		int i;
577 
578 		ap->ops->sff_dev_select(ap, 1);
579 
580 		/*
581 		 * Wait for register access.  Some ATAPI devices fail
582 		 * to set nsect/lbal after reset, so don't waste too
583 		 * much time on it.  We're gonna wait for !BSY anyway.
584 		 */
585 		for (i = 0; i < 2; i++) {
586 			u8 nsect, lbal;
587 
588 			nsect = ep93xx_pata_read_reg(drv_data,
589 				IDECTRL_ADDR_NSECT);
590 			lbal = ep93xx_pata_read_reg(drv_data,
591 				IDECTRL_ADDR_LBAL);
592 			if (nsect == 1 && lbal == 1)
593 				break;
594 			msleep(50);	/* give drive a breather */
595 		}
596 
597 		rc = ata_sff_wait_ready(link, deadline);
598 		if (rc) {
599 			if (rc != -ENODEV)
600 				return rc;
601 			ret = rc;
602 		}
603 	}
604 	/* is all this really necessary? */
605 	ap->ops->sff_dev_select(ap, 0);
606 	if (dev1)
607 		ap->ops->sff_dev_select(ap, 1);
608 	if (dev0)
609 		ap->ops->sff_dev_select(ap, 0);
610 
611 	return ret;
612 }
613 
614 /* Note: original code is ata_bus_softreset */
ep93xx_pata_bus_softreset(struct ata_port * ap,unsigned int devmask,unsigned long deadline)615 static int ep93xx_pata_bus_softreset(struct ata_port *ap, unsigned int devmask,
616 				     unsigned long deadline)
617 {
618 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
619 
620 	ep93xx_pata_write_reg(drv_data, ap->ctl, IDECTRL_ADDR_CTL);
621 	udelay(20);		/* FIXME: flush */
622 	ep93xx_pata_write_reg(drv_data, ap->ctl | ATA_SRST, IDECTRL_ADDR_CTL);
623 	udelay(20);		/* FIXME: flush */
624 	ep93xx_pata_write_reg(drv_data, ap->ctl, IDECTRL_ADDR_CTL);
625 	ap->last_ctl = ap->ctl;
626 
627 	return ep93xx_pata_wait_after_reset(&ap->link, devmask, deadline);
628 }
629 
ep93xx_pata_release_dma(struct ep93xx_pata_data * drv_data)630 static void ep93xx_pata_release_dma(struct ep93xx_pata_data *drv_data)
631 {
632 	if (drv_data->dma_rx_channel) {
633 		dma_release_channel(drv_data->dma_rx_channel);
634 		drv_data->dma_rx_channel = NULL;
635 	}
636 	if (drv_data->dma_tx_channel) {
637 		dma_release_channel(drv_data->dma_tx_channel);
638 		drv_data->dma_tx_channel = NULL;
639 	}
640 }
641 
ep93xx_pata_dma_init(struct ep93xx_pata_data * drv_data)642 static int ep93xx_pata_dma_init(struct ep93xx_pata_data *drv_data)
643 {
644 	struct platform_device *pdev = drv_data->pdev;
645 	struct device *dev = &pdev->dev;
646 	dma_cap_mask_t mask;
647 	struct dma_slave_config conf;
648 	int ret;
649 
650 	dma_cap_zero(mask);
651 	dma_cap_set(DMA_SLAVE, mask);
652 
653 	/*
654 	 * Request two channels for IDE. Another possibility would be
655 	 * to request only one channel, and reprogram it's direction at
656 	 * start of new transfer.
657 	 */
658 	drv_data->dma_rx_channel = dma_request_chan(dev, "rx");
659 	if (IS_ERR(drv_data->dma_rx_channel)) {
660 		ret = PTR_ERR(drv_data->dma_rx_channel);
661 		drv_data->dma_rx_channel = NULL;
662 		if (ret == -EPROBE_DEFER)
663 			return ret;
664 		dev_warn(dev, "rx DMA unavailable, using PIO\n");
665 		return 0;
666 	}
667 
668 	drv_data->dma_tx_channel = dma_request_chan(&pdev->dev, "tx");
669 	if (IS_ERR(drv_data->dma_tx_channel)) {
670 		ret = PTR_ERR(drv_data->dma_tx_channel);
671 		drv_data->dma_tx_channel = NULL;
672 		if (ret == -EPROBE_DEFER)
673 			goto fail_release_rx;
674 		dev_warn(dev, "tx DMA unavailable, using PIO\n");
675 		goto fail_release_rx;
676 	}
677 
678 	/* Configure receive channel direction and source address */
679 	memset(&conf, 0, sizeof(conf));
680 	conf.direction = DMA_DEV_TO_MEM;
681 	conf.src_addr = drv_data->udma_in_phys;
682 	conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
683 	ret = dmaengine_slave_config(drv_data->dma_rx_channel, &conf);
684 	if (ret) {
685 		dev_warn(dev, "failed to configure rx dma channel, using PIO\n");
686 		goto fail_release_dma;
687 	}
688 
689 	/* Configure transmit channel direction and destination address */
690 	memset(&conf, 0, sizeof(conf));
691 	conf.direction = DMA_MEM_TO_DEV;
692 	conf.dst_addr = drv_data->udma_out_phys;
693 	conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
694 	ret = dmaengine_slave_config(drv_data->dma_tx_channel, &conf);
695 	if (ret) {
696 		dev_warn(dev, "failed to configure tx dma channel, using PIO\n");
697 		goto fail_release_dma;
698 	}
699 
700 	return 0;
701 
702 fail_release_rx:
703 	dma_release_channel(drv_data->dma_rx_channel);
704 	drv_data->dma_rx_channel = NULL;
705 	if (ret == -EPROBE_DEFER)
706 		return ret;
707 	return 0;
708 
709 fail_release_dma:
710 	ep93xx_pata_release_dma(drv_data);
711 	return 0;
712 }
713 
ep93xx_pata_dma_start(struct ata_queued_cmd * qc)714 static void ep93xx_pata_dma_start(struct ata_queued_cmd *qc)
715 {
716 	struct dma_async_tx_descriptor *txd;
717 	struct ep93xx_pata_data *drv_data = qc->ap->host->private_data;
718 	void __iomem *base = drv_data->ide_base;
719 	struct ata_device *adev = qc->dev;
720 	u32 v = qc->dma_dir == DMA_TO_DEVICE ? IDEUDMAOP_RWOP : 0;
721 	struct dma_chan *channel = qc->dma_dir == DMA_TO_DEVICE
722 		? drv_data->dma_tx_channel : drv_data->dma_rx_channel;
723 
724 	txd = dmaengine_prep_slave_sg(channel, qc->sg, qc->n_elem, qc->dma_dir,
725 		DMA_CTRL_ACK);
726 	if (!txd) {
727 		dev_err(qc->ap->dev, "failed to prepare slave for sg dma\n");
728 		return;
729 	}
730 	txd->callback = NULL;
731 	txd->callback_param = NULL;
732 
733 	if (dmaengine_submit(txd) < 0) {
734 		dev_err(qc->ap->dev, "failed to submit dma transfer\n");
735 		return;
736 	}
737 	dma_async_issue_pending(channel);
738 
739 	/*
740 	 * When enabling UDMA operation, IDEUDMAOP register needs to be
741 	 * programmed in three step sequence:
742 	 * 1) set or clear the RWOP bit,
743 	 * 2) perform dummy read of the register,
744 	 * 3) set the UEN bit.
745 	 */
746 	writel(v, base + IDEUDMAOP);
747 	readl(base + IDEUDMAOP);
748 	writel(v | IDEUDMAOP_UEN, base + IDEUDMAOP);
749 
750 	writel(IDECFG_IDEEN | IDECFG_UDMA |
751 		((adev->xfer_mode - XFER_UDMA_0) << IDECFG_MODE_SHIFT),
752 		base + IDECFG);
753 }
754 
ep93xx_pata_dma_stop(struct ata_queued_cmd * qc)755 static void ep93xx_pata_dma_stop(struct ata_queued_cmd *qc)
756 {
757 	struct ep93xx_pata_data *drv_data = qc->ap->host->private_data;
758 	void __iomem *base = drv_data->ide_base;
759 
760 	/* terminate all dma transfers, if not yet finished */
761 	dmaengine_terminate_all(drv_data->dma_rx_channel);
762 	dmaengine_terminate_all(drv_data->dma_tx_channel);
763 
764 	/*
765 	 * To properly stop IDE-DMA, IDEUDMAOP register must to be cleared
766 	 * and IDECTRL register must be set to default value.
767 	 */
768 	writel(0, base + IDEUDMAOP);
769 	writel(readl(base + IDECTRL) | IDECTRL_DIOWN | IDECTRL_DIORN |
770 		IDECTRL_CS0N | IDECTRL_CS1N, base + IDECTRL);
771 
772 	ep93xx_pata_enable_pio(drv_data->ide_base,
773 		qc->dev->pio_mode - XFER_PIO_0);
774 
775 	ata_sff_dma_pause(qc->ap);
776 }
777 
ep93xx_pata_dma_setup(struct ata_queued_cmd * qc)778 static void ep93xx_pata_dma_setup(struct ata_queued_cmd *qc)
779 {
780 	qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
781 }
782 
ep93xx_pata_dma_status(struct ata_port * ap)783 static u8 ep93xx_pata_dma_status(struct ata_port *ap)
784 {
785 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
786 	u32 val = readl(drv_data->ide_base + IDEUDMASTS);
787 
788 	/*
789 	 * UDMA Status Register bits:
790 	 *
791 	 * DMAIDE - DMA request signal from UDMA state machine,
792 	 * INTIDE - INT line generated by UDMA because of errors in the
793 	 *          state machine,
794 	 * SBUSY - UDMA state machine busy, not in idle state,
795 	 * NDO   - error for data-out not completed,
796 	 * NDI   - error for data-in not completed,
797 	 * N4X   - error for data transferred not multiplies of four
798 	 *         32-bit words.
799 	 * (EP93xx UG p27-17)
800 	 */
801 	if (val & IDEUDMASTS_NDO || val & IDEUDMASTS_NDI ||
802 	    val & IDEUDMASTS_N4X || val & IDEUDMASTS_INTIDE)
803 		return ATA_DMA_ERR;
804 
805 	/* read INTRQ (INT[3]) pin input state */
806 	if (readl(drv_data->ide_base + IDECTRL) & IDECTRL_INTRQ)
807 		return ATA_DMA_INTR;
808 
809 	if (val & IDEUDMASTS_SBUSY || val & IDEUDMASTS_DMAIDE)
810 		return ATA_DMA_ACTIVE;
811 
812 	return 0;
813 }
814 
815 /* Note: original code is ata_sff_softreset */
ep93xx_pata_softreset(struct ata_link * al,unsigned int * classes,unsigned long deadline)816 static int ep93xx_pata_softreset(struct ata_link *al, unsigned int *classes,
817 				 unsigned long deadline)
818 {
819 	struct ata_port *ap = al->ap;
820 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
821 	unsigned int devmask = 0;
822 	int rc;
823 	u8 err;
824 
825 	/* determine if device 0/1 are present */
826 	if (ep93xx_pata_device_is_present(ap, 0))
827 		devmask |= (1 << 0);
828 	if (slave_possible && ep93xx_pata_device_is_present(ap, 1))
829 		devmask |= (1 << 1);
830 
831 	/* select device 0 again */
832 	ap->ops->sff_dev_select(al->ap, 0);
833 
834 	/* issue bus reset */
835 	rc = ep93xx_pata_bus_softreset(ap, devmask, deadline);
836 	/* if link is ocuppied, -ENODEV too is an error */
837 	if (rc && (rc != -ENODEV || sata_scr_valid(al))) {
838 		ata_link_err(al, "SRST failed (errno=%d)\n", rc);
839 		return rc;
840 	}
841 
842 	/* determine by signature whether we have ATA or ATAPI devices */
843 	classes[0] = ata_sff_dev_classify(&al->device[0], devmask & (1 << 0),
844 					  &err);
845 	if (slave_possible && err != 0x81)
846 		classes[1] = ata_sff_dev_classify(&al->device[1],
847 						  devmask & (1 << 1), &err);
848 
849 	return 0;
850 }
851 
852 /* Note: original code is ata_sff_drain_fifo */
ep93xx_pata_drain_fifo(struct ata_queued_cmd * qc)853 static void ep93xx_pata_drain_fifo(struct ata_queued_cmd *qc)
854 {
855 	int count;
856 	struct ata_port *ap;
857 	struct ep93xx_pata_data *drv_data;
858 
859 	/* We only need to flush incoming data when a command was running */
860 	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
861 		return;
862 
863 	ap = qc->ap;
864 	drv_data = ap->host->private_data;
865 	/* Drain up to 64K of data before we give up this recovery method */
866 	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
867 		     && count < 65536; count += 2)
868 		ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_DATA);
869 
870 	if (count)
871 		ata_port_dbg(ap, "drained %d bytes to clear DRQ.\n", count);
872 
873 }
874 
ep93xx_pata_port_start(struct ata_port * ap)875 static int ep93xx_pata_port_start(struct ata_port *ap)
876 {
877 	struct ep93xx_pata_data *drv_data = ap->host->private_data;
878 
879 	/*
880 	 * Set timings to safe values at startup (= number of ns from ATA
881 	 * specification), we'll switch to properly calculated values later.
882 	 */
883 	drv_data->t = *ata_timing_find_mode(XFER_PIO_0);
884 	return 0;
885 }
886 
887 static const struct scsi_host_template ep93xx_pata_sht = {
888 	ATA_BASE_SHT(DRV_NAME),
889 	/* ep93xx dma implementation limit */
890 	.sg_tablesize		= 32,
891 	/* ep93xx dma can't transfer 65536 bytes at once */
892 	.dma_boundary		= 0x7fff,
893 };
894 
895 static struct ata_port_operations ep93xx_pata_port_ops = {
896 	.inherits		= &ata_bmdma_port_ops,
897 
898 	.reset.softreset	= ep93xx_pata_softreset,
899 	.reset.hardreset	= ATA_OP_NULL,
900 
901 	.sff_dev_select		= ep93xx_pata_dev_select,
902 	.sff_set_devctl		= ep93xx_pata_set_devctl,
903 	.sff_check_status	= ep93xx_pata_check_status,
904 	.sff_check_altstatus	= ep93xx_pata_check_altstatus,
905 	.sff_tf_load		= ep93xx_pata_tf_load,
906 	.sff_tf_read		= ep93xx_pata_tf_read,
907 	.sff_exec_command	= ep93xx_pata_exec_command,
908 	.sff_data_xfer		= ep93xx_pata_data_xfer,
909 	.sff_drain_fifo		= ep93xx_pata_drain_fifo,
910 	.sff_irq_clear		= ATA_OP_NULL,
911 
912 	.set_piomode		= ep93xx_pata_set_piomode,
913 
914 	.bmdma_setup		= ep93xx_pata_dma_setup,
915 	.bmdma_start		= ep93xx_pata_dma_start,
916 	.bmdma_stop		= ep93xx_pata_dma_stop,
917 	.bmdma_status		= ep93xx_pata_dma_status,
918 
919 	.cable_detect		= ata_cable_unknown,
920 	.port_start		= ep93xx_pata_port_start,
921 };
922 
923 static const struct soc_device_attribute ep93xx_soc_table[] = {
924 	{ .revision = "E1", .data = (void *)ATA_UDMA3 },
925 	{ .revision = "E2", .data = (void *)ATA_UDMA4 },
926 	{ /* sentinel */ }
927 };
928 
ep93xx_pata_probe(struct platform_device * pdev)929 static int ep93xx_pata_probe(struct platform_device *pdev)
930 {
931 	struct ep93xx_pata_data *drv_data;
932 	struct ata_host *host;
933 	struct ata_port *ap;
934 	int irq;
935 	struct resource *mem_res;
936 	void __iomem *ide_base;
937 	int err;
938 
939 	/* INT[3] (IRQ_EP93XX_EXT3) line connected as pull down */
940 	irq = platform_get_irq(pdev, 0);
941 	if (irq < 0)
942 		return irq;
943 
944 	ide_base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem_res);
945 	if (IS_ERR(ide_base))
946 		return PTR_ERR(ide_base);
947 
948 	drv_data = devm_kzalloc(&pdev->dev, sizeof(*drv_data), GFP_KERNEL);
949 	if (!drv_data)
950 		return -ENOMEM;
951 
952 	drv_data->pdev = pdev;
953 	drv_data->ide_base = ide_base;
954 	drv_data->udma_in_phys = mem_res->start + IDEUDMADATAIN;
955 	drv_data->udma_out_phys = mem_res->start + IDEUDMADATAOUT;
956 	err = ep93xx_pata_dma_init(drv_data);
957 	if (err)
958 		return err;
959 
960 	/* allocate host */
961 	host = ata_host_alloc(&pdev->dev, 1);
962 	if (!host) {
963 		err = -ENOMEM;
964 		goto err_rel_dma;
965 	}
966 
967 	ep93xx_pata_clear_regs(ide_base);
968 
969 	host->private_data = drv_data;
970 
971 	ap = host->ports[0];
972 	ap->dev = &pdev->dev;
973 	ap->ops = &ep93xx_pata_port_ops;
974 	ap->flags |= ATA_FLAG_SLAVE_POSS;
975 	ap->pio_mask = ATA_PIO4;
976 
977 	/*
978 	 * Maximum UDMA modes:
979 	 * EP931x rev.E0 - UDMA2
980 	 * EP931x rev.E1 - UDMA3
981 	 * EP931x rev.E2 - UDMA4
982 	 *
983 	 * MWDMA support was removed from EP931x rev.E2,
984 	 * so this driver supports only UDMA modes.
985 	 */
986 	if (drv_data->dma_rx_channel && drv_data->dma_tx_channel) {
987 		const struct soc_device_attribute *match;
988 
989 		match = soc_device_match(ep93xx_soc_table);
990 		if (match)
991 			ap->udma_mask = (unsigned long) match->data;
992 		else
993 			ap->udma_mask = ATA_UDMA2;
994 	}
995 
996 	/* defaults, pio 0 */
997 	ep93xx_pata_enable_pio(ide_base, 0);
998 
999 	dev_info(&pdev->dev, "version " DRV_VERSION "\n");
1000 
1001 	/* activate host */
1002 	err = ata_host_activate(host, irq, ata_bmdma_interrupt, 0,
1003 		&ep93xx_pata_sht);
1004 	if (err == 0)
1005 		return 0;
1006 
1007 err_rel_dma:
1008 	ep93xx_pata_release_dma(drv_data);
1009 	return err;
1010 }
1011 
ep93xx_pata_remove(struct platform_device * pdev)1012 static void ep93xx_pata_remove(struct platform_device *pdev)
1013 {
1014 	struct ata_host *host = platform_get_drvdata(pdev);
1015 	struct ep93xx_pata_data *drv_data = host->private_data;
1016 
1017 	ata_host_detach(host);
1018 	ep93xx_pata_release_dma(drv_data);
1019 	ep93xx_pata_clear_regs(drv_data->ide_base);
1020 }
1021 
1022 static const struct of_device_id ep93xx_pata_of_ids[] = {
1023 	{ .compatible = "cirrus,ep9312-pata" },
1024 	{ /* sentinel */ }
1025 };
1026 MODULE_DEVICE_TABLE(of, ep93xx_pata_of_ids);
1027 
1028 static struct platform_driver ep93xx_pata_platform_driver = {
1029 	.driver = {
1030 		.name = DRV_NAME,
1031 		.of_match_table = ep93xx_pata_of_ids,
1032 	},
1033 	.probe = ep93xx_pata_probe,
1034 	.remove = ep93xx_pata_remove,
1035 };
1036 
1037 module_platform_driver(ep93xx_pata_platform_driver);
1038 
1039 MODULE_AUTHOR("Alessandro Zummo, Lennert Buytenhek, Joao Ramos, "
1040 		"Bartlomiej Zolnierkiewicz, Rafal Prylowski");
1041 MODULE_DESCRIPTION("low-level driver for cirrus ep93xx IDE controller");
1042 MODULE_LICENSE("GPL");
1043 MODULE_VERSION(DRV_VERSION);
1044 MODULE_ALIAS("platform:pata_ep93xx");
1045