1/*
2 * PATA driver for AT91SAM9260 Static Memory Controller
3 * with CompactFlash interface in True IDE mode
4 *
5 * Copyright (C) 2009 Matyukevich Sergey
6 *               2011 Igor Plyatov
7 *
8 * Based on:
9 *      * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
10 *      * pata_at32 driver by Kristoffer Nyborg Gregertsen
11 *      * at91_ide driver by Stanislaw Gruszka
12 *
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms of the GNU General Public License version 2
15 * as published by the Free Software Foundation.
16 *
17 */
18
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/blkdev.h>
23#include <linux/gfp.h>
24#include <scsi/scsi_host.h>
25#include <linux/ata.h>
26#include <linux/clk.h>
27#include <linux/libata.h>
28#include <linux/platform_device.h>
29#include <linux/ata_platform.h>
30
31#include <mach/at91sam9_smc.h>
32#include <mach/board.h>
33#include <asm/gpio.h>
34
35#define DRV_NAME		"pata_at91"
36#define DRV_VERSION		"0.3"
37
38#define CF_IDE_OFFSET		0x00c00000
39#define CF_ALT_IDE_OFFSET	0x00e00000
40#define CF_IDE_RES_SIZE		0x08
41#define CS_PULSE_MAXIMUM	319
42#define ER_SMC_CALC		1
43#define ER_SMC_RECALC		2
44
45struct at91_ide_info {
46	unsigned long mode;
47	unsigned int cs;
48	struct clk *mck;
49	void __iomem *ide_addr;
50	void __iomem *alt_addr;
51};
52
53/**
54 * struct smc_range - range of valid values for SMC register.
55 */
56struct smc_range {
57	int min;
58	int max;
59};
60
61/**
62 * adjust_smc_value - adjust value for one of SMC registers.
63 * @value: adjusted value
64 * @range: array of SMC ranges with valid values
65 * @size: SMC ranges array size
66 *
67 * This returns the difference between input and output value or negative
68 * in case of invalid input value.
69 * If negative returned, then output value = maximal possible from ranges.
70 */
71static int adjust_smc_value(int *value, struct smc_range *range, int size)
72{
73	int maximum = (range + size - 1)->max;
74	int remainder;
75
76	do {
77		if (*value < range->min) {
78			remainder = range->min - *value;
79			*value = range->min; /* nearest valid value */
80			return remainder;
81		} else if ((range->min <= *value) && (*value <= range->max))
82			return 0;
83
84		range++;
85	} while (--size);
86	*value = maximum;
87
88	return -1; /* invalid value */
89}
90
91/**
92 * calc_smc_vals - calculate SMC register values
93 * @dev: ATA device
94 * @setup: SMC_SETUP register value
95 * @pulse: SMC_PULSE register value
96 * @cycle: SMC_CYCLE register value
97 *
98 * This returns negative in case of invalid values for SMC registers:
99 * -ER_SMC_RECALC - recalculation required for SMC values,
100 * -ER_SMC_CALC - calculation failed (invalid input values).
101 *
102 * SMC use special coding scheme, see "Coding and Range of Timing
103 * Parameters" table from AT91SAM9 datasheets.
104 *
105 *	SMC_SETUP = 128*setup[5] + setup[4:0]
106 *	SMC_PULSE = 256*pulse[6] + pulse[5:0]
107 *	SMC_CYCLE = 256*cycle[8:7] + cycle[6:0]
108 */
109static int calc_smc_vals(struct device *dev,
110		int *setup, int *pulse, int *cycle, int *cs_pulse)
111{
112	int ret_val;
113	int err = 0;
114	struct smc_range range_setup[] = {	/* SMC_SETUP valid values */
115		{.min = 0,	.max = 31},	/* first  range */
116		{.min = 128,	.max = 159}	/* second range */
117	};
118	struct smc_range range_pulse[] = {	/* SMC_PULSE valid values */
119		{.min = 0,	.max = 63},	/* first  range */
120		{.min = 256,	.max = 319}	/* second range */
121	};
122	struct smc_range range_cycle[] = {	/* SMC_CYCLE valid values */
123		{.min = 0,	.max = 127},	/* first  range */
124		{.min = 256,	.max = 383},	/* second range */
125		{.min = 512,	.max = 639},	/* third  range */
126		{.min = 768,	.max = 895}	/* fourth range */
127	};
128
129	ret_val = adjust_smc_value(setup, range_setup, ARRAY_SIZE(range_setup));
130	if (ret_val < 0)
131		dev_warn(dev, "maximal SMC Setup value\n");
132	else
133		*cycle += ret_val;
134
135	ret_val = adjust_smc_value(pulse, range_pulse, ARRAY_SIZE(range_pulse));
136	if (ret_val < 0)
137		dev_warn(dev, "maximal SMC Pulse value\n");
138	else
139		*cycle += ret_val;
140
141	ret_val = adjust_smc_value(cycle, range_cycle, ARRAY_SIZE(range_cycle));
142	if (ret_val < 0)
143		dev_warn(dev, "maximal SMC Cycle value\n");
144
145	*cs_pulse = *cycle;
146	if (*cs_pulse > CS_PULSE_MAXIMUM) {
147		dev_err(dev, "unable to calculate valid SMC settings\n");
148		return -ER_SMC_CALC;
149	}
150
151	ret_val = adjust_smc_value(cs_pulse, range_pulse,
152					ARRAY_SIZE(range_pulse));
153	if (ret_val < 0) {
154		dev_warn(dev, "maximal SMC CS Pulse value\n");
155	} else if (ret_val != 0) {
156		*cycle = *cs_pulse;
157		dev_warn(dev, "SMC Cycle extended\n");
158		err = -ER_SMC_RECALC;
159	}
160
161	return err;
162}
163
164/**
165 * to_smc_format - convert values into SMC format
166 * @setup: SETUP value of SMC Setup Register
167 * @pulse: PULSE value of SMC Pulse Register
168 * @cycle: CYCLE value of SMC Cycle Register
169 * @cs_pulse: NCS_PULSE value of SMC Pulse Register
170 */
171static void to_smc_format(int *setup, int *pulse, int *cycle, int *cs_pulse)
172{
173	*setup = (*setup & 0x1f) | ((*setup & 0x80) >> 2);
174	*pulse = (*pulse & 0x3f) | ((*pulse & 0x100) >> 2);
175	*cycle = (*cycle & 0x7f) | ((*cycle & 0x300) >> 1);
176	*cs_pulse = (*cs_pulse & 0x3f) | ((*cs_pulse & 0x100) >> 2);
177}
178
179static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
180{
181	unsigned long mul;
182
183	/*
184	* cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
185	*     x * (f / 1_000_000_000) =
186	*     x * ((f * 65536) / 1_000_000_000) / 65536 =
187	*     x * (((f / 10_000) * 65536) / 100_000) / 65536 =
188	*/
189
190	mul = (mck_hz / 10000) << 16;
191	mul /= 100000;
192
193	return (ns * mul + 65536) >> 16;    /* rounding */
194}
195
196/**
197 * set_smc_timing - SMC timings setup.
198 * @dev: device
199 * @info: AT91 IDE info
200 * @ata: ATA timings
201 *
202 * Its assumed that write timings are same as read timings,
203 * cs_setup = 0 and cs_pulse = cycle.
204 */
205static void set_smc_timing(struct device *dev, struct ata_device *adev,
206		struct at91_ide_info *info, const struct ata_timing *ata)
207{
208	int ret = 0;
209	int use_iordy;
210	struct sam9_smc_config smc;
211	unsigned int t6z;         /* data tristate time in ns */
212	unsigned int cycle;       /* SMC Cycle width in MCK ticks */
213	unsigned int setup;       /* SMC Setup width in MCK ticks */
214	unsigned int pulse;       /* CFIOR and CFIOW pulse width in MCK ticks */
215	unsigned int cs_pulse;    /* CS4 or CS5 pulse width in MCK ticks*/
216	unsigned int tdf_cycles;  /* SMC TDF MCK ticks */
217	unsigned long mck_hz;     /* MCK frequency in Hz */
218
219	t6z = (ata->mode < XFER_PIO_5) ? 30 : 20;
220	mck_hz = clk_get_rate(info->mck);
221	cycle = calc_mck_cycles(ata->cyc8b, mck_hz);
222	setup = calc_mck_cycles(ata->setup, mck_hz);
223	pulse = calc_mck_cycles(ata->act8b, mck_hz);
224	tdf_cycles = calc_mck_cycles(t6z, mck_hz);
225
226	do {
227		ret = calc_smc_vals(dev, &setup, &pulse, &cycle, &cs_pulse);
228	} while (ret == -ER_SMC_RECALC);
229
230	if (ret == -ER_SMC_CALC)
231		dev_err(dev, "Interface may not operate correctly\n");
232
233	dev_dbg(dev, "SMC Setup=%u, Pulse=%u, Cycle=%u, CS Pulse=%u\n",
234		setup, pulse, cycle, cs_pulse);
235	to_smc_format(&setup, &pulse, &cycle, &cs_pulse);
236	/* disable or enable waiting for IORDY signal */
237	use_iordy = ata_pio_need_iordy(adev);
238	if (use_iordy)
239		info->mode |= AT91_SMC_EXNWMODE_READY;
240
241	if (tdf_cycles > 15) {
242		tdf_cycles = 15;
243		dev_warn(dev, "maximal SMC TDF Cycles value\n");
244	}
245
246	dev_dbg(dev, "Use IORDY=%u, TDF Cycles=%u\n", use_iordy, tdf_cycles);
247
248	/* SMC Setup Register */
249	smc.nwe_setup = smc.nrd_setup = setup;
250	smc.ncs_write_setup = smc.ncs_read_setup = 0;
251	/* SMC Pulse Register */
252	smc.nwe_pulse = smc.nrd_pulse = pulse;
253	smc.ncs_write_pulse = smc.ncs_read_pulse = cs_pulse;
254	/* SMC Cycle Register */
255	smc.write_cycle = smc.read_cycle = cycle;
256	/* SMC Mode Register*/
257	smc.tdf_cycles = tdf_cycles;
258	smc.mode = info->mode;
259
260	sam9_smc_configure(0, info->cs, &smc);
261}
262
263static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
264{
265	struct at91_ide_info *info = ap->host->private_data;
266	struct ata_timing timing;
267	int ret;
268
269	/* Compute ATA timing and set it to SMC */
270	ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
271	if (ret) {
272		dev_warn(ap->dev, "Failed to compute ATA timing %d, "
273			 "set PIO_0 timing\n", ret);
274		timing = *ata_timing_find_mode(XFER_PIO_0);
275	}
276	set_smc_timing(ap->dev, adev, info, &timing);
277}
278
279static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
280		unsigned char *buf, unsigned int buflen, int rw)
281{
282	struct at91_ide_info *info = dev->link->ap->host->private_data;
283	unsigned int consumed;
284	unsigned long flags;
285	struct sam9_smc_config smc;
286
287	local_irq_save(flags);
288	sam9_smc_read_mode(0, info->cs, &smc);
289
290	/* set 16bit mode before writing data */
291	smc.mode = (smc.mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_16;
292	sam9_smc_write_mode(0, info->cs, &smc);
293
294	consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
295
296	/* restore 8bit mode after data is written */
297	smc.mode = (smc.mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_8;
298	sam9_smc_write_mode(0, info->cs, &smc);
299
300	local_irq_restore(flags);
301	return consumed;
302}
303
304static struct scsi_host_template pata_at91_sht = {
305	ATA_PIO_SHT(DRV_NAME),
306};
307
308static struct ata_port_operations pata_at91_port_ops = {
309	.inherits	= &ata_sff_port_ops,
310
311	.sff_data_xfer	= pata_at91_data_xfer_noirq,
312	.set_piomode	= pata_at91_set_piomode,
313	.cable_detect	= ata_cable_40wire,
314};
315
316static int __devinit pata_at91_probe(struct platform_device *pdev)
317{
318	struct at91_cf_data *board = pdev->dev.platform_data;
319	struct device *dev = &pdev->dev;
320	struct at91_ide_info *info;
321	struct resource *mem_res;
322	struct ata_host *host;
323	struct ata_port *ap;
324
325	int irq_flags = 0;
326	int irq = 0;
327	int ret;
328
329	/*  get platform resources: IO/CTL memories and irq/rst pins */
330
331	if (pdev->num_resources != 1) {
332		dev_err(&pdev->dev, "invalid number of resources\n");
333		return -EINVAL;
334	}
335
336	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
337
338	if (!mem_res) {
339		dev_err(dev, "failed to get mem resource\n");
340		return -EINVAL;
341	}
342
343	irq = board->irq_pin;
344
345	/* init ata host */
346
347	host = ata_host_alloc(dev, 1);
348
349	if (!host)
350		return -ENOMEM;
351
352	ap = host->ports[0];
353	ap->ops = &pata_at91_port_ops;
354	ap->flags |= ATA_FLAG_SLAVE_POSS;
355	ap->pio_mask = ATA_PIO4;
356
357	if (!gpio_is_valid(irq)) {
358		ap->flags |= ATA_FLAG_PIO_POLLING;
359		ata_port_desc(ap, "no IRQ, using PIO polling");
360	}
361
362	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
363
364	if (!info) {
365		dev_err(dev, "failed to allocate memory for private data\n");
366		return -ENOMEM;
367	}
368
369	info->mck = clk_get(NULL, "mck");
370
371	if (IS_ERR(info->mck)) {
372		dev_err(dev, "failed to get access to mck clock\n");
373		return -ENODEV;
374	}
375
376	info->cs    = board->chipselect;
377	info->mode  = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
378		AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
379		AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
380
381	info->ide_addr = devm_ioremap(dev,
382			mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
383
384	if (!info->ide_addr) {
385		dev_err(dev, "failed to map IO base\n");
386		ret = -ENOMEM;
387		goto err_put;
388	}
389
390	info->alt_addr = devm_ioremap(dev,
391			mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
392
393	if (!info->alt_addr) {
394		dev_err(dev, "failed to map CTL base\n");
395		ret = -ENOMEM;
396		goto err_put;
397	}
398
399	ap->ioaddr.cmd_addr = info->ide_addr;
400	ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
401	ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
402
403	ata_sff_std_ports(&ap->ioaddr);
404
405	ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
406			(unsigned long long)mem_res->start + CF_IDE_OFFSET,
407			(unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
408
409	host->private_data = info;
410
411	return ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
412			gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
413			irq_flags, &pata_at91_sht);
414
415	if (!ret)
416		return 0;
417
418err_put:
419	clk_put(info->mck);
420	return ret;
421}
422
423static int __devexit pata_at91_remove(struct platform_device *pdev)
424{
425	struct ata_host *host = dev_get_drvdata(&pdev->dev);
426	struct at91_ide_info *info;
427
428	if (!host)
429		return 0;
430	info = host->private_data;
431
432	ata_host_detach(host);
433
434	if (!info)
435		return 0;
436
437	clk_put(info->mck);
438
439	return 0;
440}
441
442static struct platform_driver pata_at91_driver = {
443	.probe		= pata_at91_probe,
444	.remove		= __devexit_p(pata_at91_remove),
445	.driver		= {
446		.name		= DRV_NAME,
447		.owner		= THIS_MODULE,
448	},
449};
450
451module_platform_driver(pata_at91_driver);
452
453MODULE_LICENSE("GPL");
454MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
455MODULE_AUTHOR("Matyukevich Sergey");
456MODULE_VERSION(DRV_VERSION);
457
458