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