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
|
// SPDX-License-Identifier: GPL-2.0
/*
* This file is part the core part STM32 DFSDM driver
*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics.
*/
#include <linux/clk.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include "stm32-dfsdm.h"
struct stm32_dfsdm_dev_data {
unsigned int num_filters;
unsigned int num_channels;
const struct regmap_config *regmap_cfg;
};
#define STM32H7_DFSDM_NUM_FILTERS 4
#define STM32H7_DFSDM_NUM_CHANNELS 8
#define STM32MP1_DFSDM_NUM_FILTERS 6
#define STM32MP1_DFSDM_NUM_CHANNELS 8
static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
{
if (reg < DFSDM_FILTER_BASE_ADR)
return false;
/*
* Mask is done on register to avoid to list registers of all
* filter instances.
*/
switch (reg & DFSDM_FILTER_REG_MASK) {
case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK:
case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK:
case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK:
case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK:
return true;
}
return false;
}
static const struct regmap_config stm32h7_dfsdm_regmap_cfg = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = sizeof(u32),
.max_register = 0x2B8,
.volatile_reg = stm32_dfsdm_volatile_reg,
.fast_io = true,
};
static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = {
.num_filters = STM32H7_DFSDM_NUM_FILTERS,
.num_channels = STM32H7_DFSDM_NUM_CHANNELS,
.regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
};
static const struct regmap_config stm32mp1_dfsdm_regmap_cfg = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = sizeof(u32),
.max_register = 0x7fc,
.volatile_reg = stm32_dfsdm_volatile_reg,
.fast_io = true,
};
static const struct stm32_dfsdm_dev_data stm32mp1_dfsdm_data = {
.num_filters = STM32MP1_DFSDM_NUM_FILTERS,
.num_channels = STM32MP1_DFSDM_NUM_CHANNELS,
.regmap_cfg = &stm32mp1_dfsdm_regmap_cfg,
};
struct dfsdm_priv {
struct platform_device *pdev; /* platform device */
struct stm32_dfsdm dfsdm; /* common data exported for all instances */
unsigned int spi_clk_out_div; /* SPI clkout divider value */
atomic_t n_active_ch; /* number of current active channels */
struct clk *clk; /* DFSDM clock */
struct clk *aclk; /* audio clock */
};
/**
* stm32_dfsdm_start_dfsdm - start global dfsdm interface.
*
* Enable interface if n_active_ch is not null.
* @dfsdm: Handle used to retrieve dfsdm context.
*/
int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
{
struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm);
struct device *dev = &priv->pdev->dev;
unsigned int clk_div = priv->spi_clk_out_div, clk_src;
int ret;
if (atomic_inc_return(&priv->n_active_ch) == 1) {
ret = clk_prepare_enable(priv->clk);
if (ret < 0) {
dev_err(dev, "Failed to start clock\n");
goto error_ret;
}
if (priv->aclk) {
ret = clk_prepare_enable(priv->aclk);
if (ret < 0) {
dev_err(dev, "Failed to start audio clock\n");
goto disable_clk;
}
}
/* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */
clk_src = priv->aclk ? 1 : 0;
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_CKOUTSRC_MASK,
DFSDM_CHCFGR1_CKOUTSRC(clk_src));
if (ret < 0)
goto disable_aclk;
/* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_CKOUTDIV_MASK,
DFSDM_CHCFGR1_CKOUTDIV(clk_div));
if (ret < 0)
goto disable_aclk;
/* Global enable of DFSDM interface */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_DFSDMEN_MASK,
DFSDM_CHCFGR1_DFSDMEN(1));
if (ret < 0)
goto disable_aclk;
}
dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
atomic_read(&priv->n_active_ch));
return 0;
disable_aclk:
clk_disable_unprepare(priv->aclk);
disable_clk:
clk_disable_unprepare(priv->clk);
error_ret:
atomic_dec(&priv->n_active_ch);
return ret;
}
EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);
/**
* stm32_dfsdm_stop_dfsdm - stop global DFSDM interface.
*
* Disable interface if n_active_ch is null
* @dfsdm: Handle used to retrieve dfsdm context.
*/
int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
{
struct dfsdm_priv *priv = container_of(dfsdm, struct dfsdm_priv, dfsdm);
int ret;
if (atomic_dec_and_test(&priv->n_active_ch)) {
/* Global disable of DFSDM interface */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_DFSDMEN_MASK,
DFSDM_CHCFGR1_DFSDMEN(0));
if (ret < 0)
return ret;
/* Stop SPI CLKOUT */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
DFSDM_CHCFGR1_CKOUTDIV_MASK,
DFSDM_CHCFGR1_CKOUTDIV(0));
if (ret < 0)
return ret;
clk_disable_unprepare(priv->clk);
if (priv->aclk)
clk_disable_unprepare(priv->aclk);
}
dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
atomic_read(&priv->n_active_ch));
return 0;
}
EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm);
static int stm32_dfsdm_parse_of(struct platform_device *pdev,
struct dfsdm_priv *priv)
{
struct device_node *node = pdev->dev.of_node;
struct resource *res;
unsigned long clk_freq, divider;
unsigned int spi_freq, rem;
int ret;
if (!node)
return -EINVAL;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "Failed to get memory resource\n");
return -ENODEV;
}
priv->dfsdm.phys_base = res->start;
priv->dfsdm.base = devm_ioremap_resource(&pdev->dev, res);
/*
* "dfsdm" clock is mandatory for DFSDM peripheral clocking.
* "dfsdm" or "audio" clocks can be used as source clock for
* the SPI clock out signal and internal processing, depending
* on use case.
*/
priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
if (IS_ERR(priv->clk)) {
dev_err(&pdev->dev, "No stm32_dfsdm_clk clock found\n");
return -EINVAL;
}
priv->aclk = devm_clk_get(&pdev->dev, "audio");
if (IS_ERR(priv->aclk))
priv->aclk = NULL;
if (priv->aclk)
clk_freq = clk_get_rate(priv->aclk);
else
clk_freq = clk_get_rate(priv->clk);
/* SPI clock out frequency */
ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
&spi_freq);
if (ret < 0) {
/* No SPI master mode */
return 0;
}
divider = div_u64_rem(clk_freq, spi_freq, &rem);
/* Round up divider when ckout isn't precise, not to exceed spi_freq */
if (rem)
divider++;
/* programmable divider is in range of [2:256] */
if (divider < 2 || divider > 256) {
dev_err(&pdev->dev, "spi-max-frequency not achievable\n");
return -EINVAL;
}
/* SPI clock output divider is: divider = CKOUTDIV + 1 */
priv->spi_clk_out_div = divider - 1;
priv->dfsdm.spi_master_freq = clk_freq / (priv->spi_clk_out_div + 1);
if (rem) {
dev_warn(&pdev->dev, "SPI clock not accurate\n");
dev_warn(&pdev->dev, "%ld = %d * %d + %d\n",
clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem);
}
return 0;
};
static const struct of_device_id stm32_dfsdm_of_match[] = {
{
.compatible = "st,stm32h7-dfsdm",
.data = &stm32h7_dfsdm_data,
},
{
.compatible = "st,stm32mp1-dfsdm",
.data = &stm32mp1_dfsdm_data,
},
{}
};
MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);
static int stm32_dfsdm_probe
|