summaryrefslogtreecommitdiff
path: root/drivers/mfd/atmel-smc.c
blob: d96f1d689e7fbda14e83dedc6cc9a381affc85a0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Atmel SMC (Static Memory Controller) helper functions.
 *
 * Copyright (C) 2017 Atmel
 * Copyright (C) 2017 Free Electrons
 *
 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
 */

#include <linux/mfd/syscon/atmel-smc.h>
#include <linux/string.h>

/**
 * atmel_smc_cs_conf_init - initialize a SMC CS conf
 * @conf: the SMC CS conf to initialize
 *
 * Set all fields to 0 so that one can start defining a new config.
 */
void atmel_smc_cs_conf_init(struct atmel_smc_cs_conf *conf)
{
	memset(conf, 0, sizeof(*conf));
}
EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_init);

/**
 * atmel_smc_cs_encode_ncycles - encode a number of MCK clk cycles in the
 *				 format expected by the SMC engine
 * @ncycles: number of MCK clk cycles
 * @msbpos: position of the MSB part of the timing field
 * @msbwidth: width of the MSB part of the timing field
 * @msbfactor: factor applied to the MSB
 * @encodedval: param used to store the encoding result
 *
 * This function encodes the @ncycles value as described in the datasheet
 * (section "SMC Setup/Pulse/Cycle/Timings Register"). This is a generic
 * helper which called with different parameter depending on the encoding
 * scheme.
 *
 * If the @ncycles value is too big to be encoded, -ERANGE is returned and
 * the encodedval is contains the maximum val. Otherwise, 0 is returned.
 */
static int atmel_smc_cs_encode_ncycles(unsigned int ncycles,
				       unsigned int msbpos,
				       unsigned int msbwidth,
				       unsigned int msbfactor,
				       unsigned int *encodedval)
{
	unsigned int lsbmask = GENMASK(msbpos - 1, 0);
	unsigned int msbmask = GENMASK(msbwidth - 1, 0);
	unsigned int msb, lsb;
	int ret = 0;

	msb = ncycles / msbfactor;
	lsb = ncycles % msbfactor;

	if (lsb > lsbmask) {
		lsb = 0;
		msb++;
	}

	/*
	 * Let's just put the maximum we can if the requested setting does
	 * not fit in the register field.
	 * We still return -ERANGE in case the caller cares.
	 */
	if (msb > msbmask) {
		msb = msbmask;
		lsb = lsbmask;
		ret = -ERANGE;
	}

	*encodedval = (msb << msbpos) | lsb;

	return ret;
}

/**
 * atmel_smc_cs_conf_set_timing - set the SMC CS conf Txx parameter to a
 *				  specific value
 * @conf: SMC CS conf descriptor
 * @shift: the position of the Txx field in the TIMINGS register
 * @ncycles: value (expressed in MCK clk cycles) to assign to this Txx
 *	     parameter
 *
 * This function encodes the @ncycles value as described in the datasheet
 * (section "SMC Timings Register"), and then stores the result in the
 * @conf->timings field at @shift position.
 *
 * Returns -EINVAL if shift is invalid, -ERANGE if ncycles does not fit in
 * the field, and 0 otherwise.
 */
int atmel_smc_cs_conf_set_timing(struct atmel_smc_cs_conf *conf,
				 unsigned int shift, unsigned int ncycles)
{
	unsigned int val;
	int ret;

	if (shift != ATMEL_HSMC_TIMINGS_TCLR_SHIFT &&
	    shift != ATMEL_HSMC_TIMINGS_TADL_SHIFT &&
	    shift != ATMEL_HSMC_TIMINGS_TAR_SHIFT &&
	    shift != ATMEL_HSMC_TIMINGS_TRR_SHIFT &&
	    shift != ATMEL_HSMC_TIMINGS_TWB_SHIFT)
		return -EINVAL;

	/*
	 * The formula described in atmel datasheets (section "HSMC Timings
	 * Register"):
	 *
	 * ncycles = (Txx[3] * 64) + Txx[2:0]
	 */
	ret = atmel_smc_cs_encode_ncycles(ncycles, 3, 1, 64, &val);
	conf->timings &= ~GENMASK(shift + 3, shift);
	conf->timings |= val << shift;

	return ret;
}
EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_timing);

/**
 * atmel_smc_cs_conf_set_setup - set the SMC CS conf xx_SETUP parameter to a
 *				 specific value
 * @conf: SMC CS conf descriptor
 * @shift: the position of the xx_SETUP field in the SETUP register
 * @ncycles: value (expressed in MCK clk cycles) to assign to this xx_SETUP
 *	     parameter
 *
 * This function encodes the @ncycles value as described in the datasheet
 * (section "SMC Setup Register"), and then stores the result in the
 * @conf->setup field at @shift position.
 *
 * Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
 * the field, and 0 otherwise.
 */
int atmel_smc_cs_conf_set_setup(struct atmel_smc_cs_conf *conf,
				unsigned int shift, unsigned int ncycles)
{
	unsigned int val;
	int ret;

	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NCS_WR_SHIFT &&
	    shift != ATMEL_SMC_NRD_SHIFT && shift != ATMEL_SMC_NCS_RD_SHIFT)
		return -EINVAL;

	/*
	 * The formula described in atmel datasheets (section "SMC Setup
	 * Register"):
	 *
	 * ncycles = (128 * xx_SETUP[5]) + xx_SETUP[4:0]
	 */
	ret = atmel_smc_cs_encode_ncycles(ncycles, 5, 1, 128, &val);
	conf->setup &= ~GENMASK(shift + 7, shift);
	conf->setup |= val << shift;

	return ret;
}
EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_setup);

/**
 * atmel_smc_cs_conf_set_pulse - set the SMC CS conf xx_PULSE parameter to a
 *				 specific value
 * @conf: SMC CS conf descriptor
 * @shift: the position of the xx_PULSE field in the PULSE register
 * @ncycles: value (expressed in MCK clk cycles) to assign to this xx_PULSE
 *	     parameter
 *
 * This function encodes the @ncycles value as described in the datasheet
 * (section "SMC Pulse Register"), and then stores the result in the
 * @conf->setup field at @shift position.
 *
 * Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
 * the field, and 0 otherwise.
 */
int atmel_smc_cs_conf_set_pulse(struct atmel_smc_cs_conf *conf,
				unsigned int shift, unsigned int ncycles)
{
	unsigned int val;
	int ret;

	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NCS_WR_SHIFT &&
	    shift != ATMEL_SMC_NRD_SHIFT && shift != ATMEL_SMC_NCS_RD_SHIFT)
		return -EINVAL;

	/*
	 * The formula described in atmel datasheets (section "SMC Pulse
	 * Register"):
	 *
	 * ncycles = (256 * xx_PULSE[6]) + xx_PULSE[5:0]
	 */
	ret = atmel_smc_cs_encode_ncycles(ncycles, 6, 1, 256, &val);
	conf->pulse &= ~GENMASK(shift + 7, shift);
	conf->pulse |= val << shift;

	return ret;
}
EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_pulse);

/**
 * atmel_smc_cs_conf_set_cycle - set the SMC CS conf xx_CYCLE parameter to a
 *				 specific value
 * @conf: SMC CS conf descriptor
 * @shift: the position of the xx_CYCLE field in the CYCLE register
 * @ncycles: value (expressed in MCK clk cycles) to assign to this xx_CYCLE
 *	     parameter
 *
 * This function encodes the @ncycles value as described in the datasheet
 * (section "SMC Cycle Register"), and then stores the result in the
 * @conf->setup field at @shift position.
 *
 * Returns -EINVAL if @shift is invalid, -ERANGE if @ncycles does not fit in
 * the field, and 0 otherwise.
 */
int atmel_smc_cs_conf_set_cycle(struct atmel_smc_cs_conf *conf,
				unsigned int shift, unsigned int ncycles)
{
	unsigned int val;
	int ret;

	if (shift != ATMEL_SMC_NWE_SHIFT && shift != ATMEL_SMC_NRD_SHIFT)
		return -EINVAL;

	/*
	 * The formula described in atmel datasheets (section "SMC Cycle
	 * Register"):
	 *
	 * ncycles = (xx_CYCLE[8:7] * 256) + xx_CYCLE[6:0]
	 */
	ret = atmel_smc_cs_encode_ncycles(ncycles, 7, 2, 256, &val);
	conf->cycle &= ~GENMASK(shift + 15, shift);
	conf->cycle |= val << shift;

	return ret;
}
EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_set_cycle);

/**
 * atmel_smc_cs_conf_apply - apply an SMC CS conf
 * @regmap: the SMC regmap
 * @cs: the CS id
 * @conf: the SMC CS conf to apply
 *
 * Applies an SMC CS configuration.
 * Only valid on at91sam9/avr32 SoCs.
 */
void atmel_smc_cs_conf_apply(struct regmap *regmap, int cs,
			     const struct atmel_smc_cs_conf *conf)
{
	regmap_write(regmap, ATMEL_SMC_SETUP(cs), conf->setup);
	regmap_write(regmap, ATMEL_SMC_PULSE(cs), conf->pulse);
	regmap_write(regmap, ATMEL_SMC_CYCLE(cs), conf->cycle);
	regmap_write(regmap, ATMEL_SMC_MODE(cs), conf->mode);
}
EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_apply);

/**
 * atmel_hsmc_cs_conf_apply - apply an SMC CS conf
 * @regmap: the HSMC regmap
 * @cs: the CS id
 * @layout: the layout of registers
 * @conf: the SMC CS conf to apply
 *
 * Applies an SMC CS configuration.
 * Only valid on post-sama5 SoCs.
 */
void atmel_hsmc_cs_conf_apply(struct regmap *regmap,
			      const struct atmel_hsmc_reg_layout *layout,
			      int cs, const struct atmel_smc_cs_conf *conf)
{
	regmap_write(regmap, ATMEL_HSMC_SETUP(layout, cs), conf->setup);
	regmap_write(regmap, ATMEL_HSMC_PULSE(layout, cs), conf->pulse);
	regmap_write(regmap, ATMEL_HSMC_CYCLE(layout, cs), conf->cycle);
	regmap_write(regmap, ATMEL_HSMC_TIMINGS(layout, cs), conf->timings);
	regmap_write(regmap, ATMEL_HSMC_MODE(layout, cs), conf->mode);
}
EXPORT_SYMBOL_GPL(atmel_hsmc_cs_conf_apply);

/**
 * atmel_smc_cs_conf_get - retrieve the current SMC CS conf
 * @regmap: the SMC regmap
 * @cs: the CS id
 * @conf: the SMC CS conf object to store the current conf
 *
 * Retrieve the SMC CS configuration.
 * Only valid on at91sam9/avr32 SoCs.
 */
void atmel_smc_cs_conf_get(struct regmap *regmap, int cs,
			   struct atmel_smc_cs_conf *conf)
{
	regmap_read(regmap, ATMEL_SMC_SETUP(cs), &conf->setup);
	regmap_read(regmap, ATMEL_SMC_PULSE(cs), &conf->pulse);
	regmap_read(regmap, ATMEL_SMC_CYCLE(cs), &conf->cycle);
	regmap_read(regmap, ATMEL_SMC_MODE(cs), &conf->mode);
}
EXPORT_SYMBOL_GPL(atmel_smc_cs_conf_get);

/**
 * atmel_hsmc_cs_conf_get - retrieve the current SMC CS conf
 * @regmap: the HSMC regmap
 * @cs: the CS id
 * @layout: the layout of registers
 * @conf: the SMC CS conf object to store the current conf
 *
 * Retrieve the SMC CS configuration.
 * Only valid on post-sama5 SoCs.
 */
void atmel_hsmc_cs_conf_get(struct regmap *regmap,
			    const struct atmel_hsmc_reg_layout *layout,
			    int cs, struct atmel_smc_cs_conf *conf)
{
	regmap_read(regmap, ATMEL_HSMC_SETUP(layout, cs), &conf->setup);
	regmap_read(regmap, ATMEL_HSMC_PULSE(layout, cs), &conf->pulse);
	regmap_read(regmap, ATMEL_HSMC_CYCLE(layout, cs), &conf->cycle);
	regmap_read(regmap, ATMEL_HSMC_TIMINGS(layout, cs), &conf->timings);
	regmap_read(regmap, ATMEL_HSMC_MODE(layout, cs), &conf->mode);
}
EXPORT_SYMBOL_GPL(atmel_hsmc_cs_conf_get);

static const struct atmel_hsmc_reg_layout sama5d3_reg_layout = {
	.timing_regs_offset = 0x600,
};

static const struct atmel_hsmc_reg_layout sama5d2_reg_layout = {
	.timing_regs_offset = 0x700,
};

static const struct of_device_id atmel_smc_ids[] = {
	{ .compatible = "atmel,at91sam9260-smc", .data = NULL },
	{ .compatible = "atmel,sama5d3-smc", .data = &sama5d3_reg_layout },
	{ .compatible = "atmel,sama5d2-smc", .data = &sama5d2_reg_layout },
	{ /* sentinel */ },
};

/**
 * atmel_hsmc_get_reg_layout - retrieve the layout of HSMC registers
 * @np: the HSMC regmap
 *
 * Retrieve the layout of HSMC registers.
 *
 * Returns NULL in case of SMC, a struct atmel_hsmc_reg_layout pointer
 * in HSMC case, otherwise ERR_PTR(-EINVAL).
 */
const struct atmel_hsmc_reg_layout *
atmel_hsmc_get_reg_layout(struct device_node *np)
{
	const struct of_device_id *match;

	match = of_match_node(atmel_smc_ids, np);

	return match ? match->data : ERR_PTR(-EINVAL);
}
EXPORT_SYMBOL_GPL(atmel_hsmc_get_reg_layout);