1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2020 Microchip
4 *
5 * Author: Kamel Bouhara <kamel.bouhara@bootlin.com>
6 */
7 #include <linux/clk.h>
8 #include <linux/counter.h>
9 #include <linux/mfd/syscon.h>
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/of.h>
13 #include <linux/of_device.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16 #include <soc/at91/atmel_tcb.h>
17
18 #define ATMEL_TC_CMR_MASK (ATMEL_TC_LDRA_RISING | ATMEL_TC_LDRB_FALLING | \
19 ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_LDBDIS | \
20 ATMEL_TC_LDBSTOP)
21
22 #define ATMEL_TC_QDEN BIT(8)
23 #define ATMEL_TC_POSEN BIT(9)
24
25 struct mchp_tc_data {
26 const struct atmel_tcb_config *tc_cfg;
27 struct regmap *regmap;
28 int qdec_mode;
29 int num_channels;
30 int channel[2];
31 };
32
33 static const enum counter_function mchp_tc_count_functions[] = {
34 COUNTER_FUNCTION_INCREASE,
35 COUNTER_FUNCTION_QUADRATURE_X4,
36 };
37
38 static const enum counter_synapse_action mchp_tc_synapse_actions[] = {
39 COUNTER_SYNAPSE_ACTION_NONE,
40 COUNTER_SYNAPSE_ACTION_RISING_EDGE,
41 COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
42 COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
43 };
44
45 static struct counter_signal mchp_tc_count_signals[] = {
46 {
47 .id = 0,
48 .name = "Channel A",
49 },
50 {
51 .id = 1,
52 .name = "Channel B",
53 }
54 };
55
56 static struct counter_synapse mchp_tc_count_synapses[] = {
57 {
58 .actions_list = mchp_tc_synapse_actions,
59 .num_actions = ARRAY_SIZE(mchp_tc_synapse_actions),
60 .signal = &mchp_tc_count_signals[0]
61 },
62 {
63 .actions_list = mchp_tc_synapse_actions,
64 .num_actions = ARRAY_SIZE(mchp_tc_synapse_actions),
65 .signal = &mchp_tc_count_signals[1]
66 }
67 };
68
mchp_tc_count_function_read(struct counter_device * counter,struct counter_count * count,enum counter_function * function)69 static int mchp_tc_count_function_read(struct counter_device *counter,
70 struct counter_count *count,
71 enum counter_function *function)
72 {
73 struct mchp_tc_data *const priv = counter_priv(counter);
74
75 if (priv->qdec_mode)
76 *function = COUNTER_FUNCTION_QUADRATURE_X4;
77 else
78 *function = COUNTER_FUNCTION_INCREASE;
79
80 return 0;
81 }
82
mchp_tc_count_function_write(struct counter_device * counter,struct counter_count * count,enum counter_function function)83 static int mchp_tc_count_function_write(struct counter_device *counter,
84 struct counter_count *count,
85 enum counter_function function)
86 {
87 struct mchp_tc_data *const priv = counter_priv(counter);
88 u32 bmr, cmr;
89
90 regmap_read(priv->regmap, ATMEL_TC_BMR, &bmr);
91 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr);
92
93 /* Set capture mode */
94 cmr &= ~ATMEL_TC_WAVE;
95
96 switch (function) {
97 case COUNTER_FUNCTION_INCREASE:
98 priv->qdec_mode = 0;
99 /* Set highest rate based on whether soc has gclk or not */
100 bmr &= ~(ATMEL_TC_QDEN | ATMEL_TC_POSEN);
101 if (priv->tc_cfg->has_gclk)
102 cmr |= ATMEL_TC_TIMER_CLOCK2;
103 else
104 cmr |= ATMEL_TC_TIMER_CLOCK1;
105 /* Setup the period capture mode */
106 cmr |= ATMEL_TC_CMR_MASK;
107 cmr &= ~(ATMEL_TC_ABETRG | ATMEL_TC_XC0);
108 break;
109 case COUNTER_FUNCTION_QUADRATURE_X4:
110 if (!priv->tc_cfg->has_qdec)
111 return -EINVAL;
112 /* In QDEC mode settings both channels 0 and 1 are required */
113 if (priv->num_channels < 2 || priv->channel[0] != 0 ||
114 priv->channel[1] != 1) {
115 pr_err("Invalid channels number or id for quadrature mode\n");
116 return -EINVAL;
117 }
118 priv->qdec_mode = 1;
119 bmr |= ATMEL_TC_QDEN | ATMEL_TC_POSEN;
120 cmr |= ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_ABETRG | ATMEL_TC_XC0;
121 break;
122 default:
123 /* should never reach this path */
124 return -EINVAL;
125 }
126
127 regmap_write(priv->regmap, ATMEL_TC_BMR, bmr);
128 regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), cmr);
129
130 /* Enable clock and trigger counter */
131 regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CCR),
132 ATMEL_TC_CLKEN | ATMEL_TC_SWTRG);
133
134 if (priv->qdec_mode) {
135 regmap_write(priv->regmap,
136 ATMEL_TC_REG(priv->channel[1], CMR), cmr);
137 regmap_write(priv->regmap,
138 ATMEL_TC_REG(priv->channel[1], CCR),
139 ATMEL_TC_CLKEN | ATMEL_TC_SWTRG);
140 }
141
142 return 0;
143 }
144
mchp_tc_count_signal_read(struct counter_device * counter,struct counter_signal * signal,enum counter_signal_level * lvl)145 static int mchp_tc_count_signal_read(struct counter_device *counter,
146 struct counter_signal *signal,
147 enum counter_signal_level *lvl)
148 {
149 struct mchp_tc_data *const priv = counter_priv(counter);
150 bool sigstatus;
151 u32 sr;
152
153 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr);
154
155 if (signal->id == 1)
156 sigstatus = (sr & ATMEL_TC_MTIOB);
157 else
158 sigstatus = (sr & ATMEL_TC_MTIOA);
159
160 *lvl = sigstatus ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW;
161
162 return 0;
163 }
164
mchp_tc_count_action_read(struct counter_device * counter,struct counter_count * count,struct counter_synapse * synapse,enum counter_synapse_action * action)165 static int mchp_tc_count_action_read(struct counter_device *counter,
166 struct counter_count *count,
167 struct counter_synapse *synapse,
168 enum counter_synapse_action *action)
169 {
170 struct mchp_tc_data *const priv = counter_priv(counter);
171 u32 cmr;
172
173 if (priv->qdec_mode) {
174 *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
175 return 0;
176 }
177
178 /* Only TIOA signal is evaluated in non-QDEC mode */
179 if (synapse->signal->id != 0) {
180 *action = COUNTER_SYNAPSE_ACTION_NONE;
181 return 0;
182 }
183
184 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr);
185
186 switch (cmr & ATMEL_TC_ETRGEDG) {
187 default:
188 *action = COUNTER_SYNAPSE_ACTION_NONE;
189 break;
190 case ATMEL_TC_ETRGEDG_RISING:
191 *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
192 break;
193 case ATMEL_TC_ETRGEDG_FALLING:
194 *action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE;
195 break;
196 case ATMEL_TC_ETRGEDG_BOTH:
197 *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
198 break;
199 }
200
201 return 0;
202 }
203
mchp_tc_count_action_write(struct counter_device * counter,struct counter_count * count,struct counter_synapse * synapse,enum counter_synapse_action action)204 static int mchp_tc_count_action_write(struct counter_device *counter,
205 struct counter_count *count,
206 struct counter_synapse *synapse,
207 enum counter_synapse_action action)
208 {
209 struct mchp_tc_data *const priv = counter_priv(counter);
210 u32 edge = ATMEL_TC_ETRGEDG_NONE;
211
212 /* QDEC mode is rising edge only; only TIOA handled in non-QDEC mode */
213 if (priv->qdec_mode || synapse->signal->id != 0)
214 return -EINVAL;
215
216 switch (action) {
217 case COUNTER_SYNAPSE_ACTION_NONE:
218 edge = ATMEL_TC_ETRGEDG_NONE;
219 break;
220 case COUNTER_SYNAPSE_ACTION_RISING_EDGE:
221 edge = ATMEL_TC_ETRGEDG_RISING;
222 break;
223 case COUNTER_SYNAPSE_ACTION_FALLING_EDGE:
224 edge = ATMEL_TC_ETRGEDG_FALLING;
225 break;
226 case COUNTER_SYNAPSE_ACTION_BOTH_EDGES:
227 edge = ATMEL_TC_ETRGEDG_BOTH;
228 break;
229 default:
230 /* should never reach this path */
231 return -EINVAL;
232 }
233
234 return regmap_write_bits(priv->regmap,
235 ATMEL_TC_REG(priv->channel[0], CMR),
236 ATMEL_TC_ETRGEDG, edge);
237 }
238
mchp_tc_count_read(struct counter_device * counter,struct counter_count * count,u64 * val)239 static int mchp_tc_count_read(struct counter_device *counter,
240 struct counter_count *count, u64 *val)
241 {
242 struct mchp_tc_data *const priv = counter_priv(counter);
243 u32 cnt;
244
245 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt);
246 *val = cnt;
247
248 return 0;
249 }
250
251 static struct counter_count mchp_tc_counts[] = {
252 {
253 .id = 0,
254 .name = "Timer Counter",
255 .functions_list = mchp_tc_count_functions,
256 .num_functions = ARRAY_SIZE(mchp_tc_count_functions),
257 .synapses = mchp_tc_count_synapses,
258 .num_synapses = ARRAY_SIZE(mchp_tc_count_synapses),
259 },
260 };
261
262 static const struct counter_ops mchp_tc_ops = {
263 .signal_read = mchp_tc_count_signal_read,
264 .count_read = mchp_tc_count_read,
265 .function_read = mchp_tc_count_function_read,
266 .function_write = mchp_tc_count_function_write,
267 .action_read = mchp_tc_count_action_read,
268 .action_write = mchp_tc_count_action_write
269 };
270
271 static const struct atmel_tcb_config tcb_rm9200_config = {
272 .counter_width = 16,
273 };
274
275 static const struct atmel_tcb_config tcb_sam9x5_config = {
276 .counter_width = 32,
277 };
278
279 static const struct atmel_tcb_config tcb_sama5d2_config = {
280 .counter_width = 32,
281 .has_gclk = true,
282 .has_qdec = true,
283 };
284
285 static const struct atmel_tcb_config tcb_sama5d3_config = {
286 .counter_width = 32,
287 .has_qdec = true,
288 };
289
290 static const struct of_device_id atmel_tc_of_match[] = {
291 { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
292 { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
293 { .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, },
294 { .compatible = "atmel,sama5d3-tcb", .data = &tcb_sama5d3_config, },
295 { /* sentinel */ }
296 };
297
mchp_tc_clk_remove(void * ptr)298 static void mchp_tc_clk_remove(void *ptr)
299 {
300 clk_disable_unprepare((struct clk *)ptr);
301 }
302
mchp_tc_probe(struct platform_device * pdev)303 static int mchp_tc_probe(struct platform_device *pdev)
304 {
305 struct device_node *np = pdev->dev.of_node;
306 const struct atmel_tcb_config *tcb_config;
307 const struct of_device_id *match;
308 struct counter_device *counter;
309 struct mchp_tc_data *priv;
310 char clk_name[7];
311 struct regmap *regmap;
312 struct clk *clk[3];
313 int channel;
314 int ret, i;
315
316 counter = devm_counter_alloc(&pdev->dev, sizeof(*priv));
317 if (!counter)
318 return -ENOMEM;
319 priv = counter_priv(counter);
320
321 match = of_match_node(atmel_tc_of_match, np->parent);
322 tcb_config = match->data;
323 if (!tcb_config) {
324 dev_err(&pdev->dev, "No matching parent node found\n");
325 return -ENODEV;
326 }
327
328 regmap = syscon_node_to_regmap(np->parent);
329 if (IS_ERR(regmap))
330 return PTR_ERR(regmap);
331
332 /* max. channels number is 2 when in QDEC mode */
333 priv->num_channels = of_property_count_u32_elems(np, "reg");
334 if (priv->num_channels < 0) {
335 dev_err(&pdev->dev, "Invalid or missing channel\n");
336 return -EINVAL;
337 }
338
339 /* Register channels and initialize clocks */
340 for (i = 0; i < priv->num_channels; i++) {
341 ret = of_property_read_u32_index(np, "reg", i, &channel);
342 if (ret < 0 || channel > 2)
343 return -ENODEV;
344
345 priv->channel[i] = channel;
346
347 snprintf(clk_name, sizeof(clk_name), "t%d_clk", channel);
348
349 clk[i] = of_clk_get_by_name(np->parent, clk_name);
350 if (IS_ERR(clk[i])) {
351 /* Fallback to t0_clk */
352 clk[i] = of_clk_get_by_name(np->parent, "t0_clk");
353 if (IS_ERR(clk[i]))
354 return PTR_ERR(clk[i]);
355 }
356
357 ret = clk_prepare_enable(clk[i]);
358 if (ret)
359 return ret;
360
361 ret = devm_add_action_or_reset(&pdev->dev,
362 mchp_tc_clk_remove,
363 clk[i]);
364 if (ret)
365 return ret;
366
367 dev_dbg(&pdev->dev,
368 "Initialized capture mode on channel %d\n",
369 channel);
370 }
371
372 priv->tc_cfg = tcb_config;
373 priv->regmap = regmap;
374 counter->name = dev_name(&pdev->dev);
375 counter->parent = &pdev->dev;
376 counter->ops = &mchp_tc_ops;
377 counter->num_counts = ARRAY_SIZE(mchp_tc_counts);
378 counter->counts = mchp_tc_counts;
379 counter->num_signals = ARRAY_SIZE(mchp_tc_count_signals);
380 counter->signals = mchp_tc_count_signals;
381
382 ret = devm_counter_add(&pdev->dev, counter);
383 if (ret < 0)
384 return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n");
385
386 return 0;
387 }
388
389 static const struct of_device_id mchp_tc_dt_ids[] = {
390 { .compatible = "microchip,tcb-capture", },
391 { /* sentinel */ },
392 };
393 MODULE_DEVICE_TABLE(of, mchp_tc_dt_ids);
394
395 static struct platform_driver mchp_tc_driver = {
396 .probe = mchp_tc_probe,
397 .driver = {
398 .name = "microchip-tcb-capture",
399 .of_match_table = mchp_tc_dt_ids,
400 },
401 };
402 module_platform_driver(mchp_tc_driver);
403
404 MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
405 MODULE_DESCRIPTION("Microchip TCB Capture driver");
406 MODULE_LICENSE("GPL v2");
407 MODULE_IMPORT_NS(COUNTER);
408
