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  1// SPDX-License-Identifier: GPL-2.0
  2// SPI to CAN driver for the Texas Instruments TCAN4x5x
  3// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
  4
  5#include "tcan4x5x.h"
  6
  7#define TCAN4X5X_EXT_CLK_DEF 40000000
  8
  9#define TCAN4X5X_DEV_ID1 0x00
 10#define TCAN4X5X_DEV_ID1_TCAN 0x4e414354 /* ASCII TCAN */
 11#define TCAN4X5X_DEV_ID2 0x04
 12#define TCAN4X5X_REV 0x08
 13#define TCAN4X5X_STATUS 0x0C
 14#define TCAN4X5X_ERROR_STATUS_MASK 0x10
 15#define TCAN4X5X_CONTROL 0x14
 16
 17#define TCAN4X5X_CONFIG 0x800
 18#define TCAN4X5X_TS_PRESCALE 0x804
 19#define TCAN4X5X_TEST_REG 0x808
 20#define TCAN4X5X_INT_FLAGS 0x820
 21#define TCAN4X5X_MCAN_INT_REG 0x824
 22#define TCAN4X5X_INT_EN 0x830
 23
 24/* Interrupt bits */
 25#define TCAN4X5X_CANBUSTERMOPEN_INT_EN BIT(30)
 26#define TCAN4X5X_CANHCANL_INT_EN BIT(29)
 27#define TCAN4X5X_CANHBAT_INT_EN BIT(28)
 28#define TCAN4X5X_CANLGND_INT_EN BIT(27)
 29#define TCAN4X5X_CANBUSOPEN_INT_EN BIT(26)
 30#define TCAN4X5X_CANBUSGND_INT_EN BIT(25)
 31#define TCAN4X5X_CANBUSBAT_INT_EN BIT(24)
 32#define TCAN4X5X_UVSUP_INT_EN BIT(22)
 33#define TCAN4X5X_UVIO_INT_EN BIT(21)
 34#define TCAN4X5X_TSD_INT_EN BIT(19)
 35#define TCAN4X5X_ECCERR_INT_EN BIT(16)
 36#define TCAN4X5X_CANINT_INT_EN BIT(15)
 37#define TCAN4X5X_LWU_INT_EN BIT(14)
 38#define TCAN4X5X_CANSLNT_INT_EN BIT(10)
 39#define TCAN4X5X_CANDOM_INT_EN BIT(8)
 40#define TCAN4X5X_CANBUS_ERR_INT_EN BIT(5)
 41#define TCAN4X5X_BUS_FAULT BIT(4)
 42#define TCAN4X5X_MCAN_INT BIT(1)
 43#define TCAN4X5X_ENABLE_TCAN_INT \
 44	(TCAN4X5X_MCAN_INT | TCAN4X5X_BUS_FAULT | \
 45	 TCAN4X5X_CANBUS_ERR_INT_EN | TCAN4X5X_CANINT_INT_EN)
 46
 47/* MCAN Interrupt bits */
 48#define TCAN4X5X_MCAN_IR_ARA BIT(29)
 49#define TCAN4X5X_MCAN_IR_PED BIT(28)
 50#define TCAN4X5X_MCAN_IR_PEA BIT(27)
 51#define TCAN4X5X_MCAN_IR_WD BIT(26)
 52#define TCAN4X5X_MCAN_IR_BO BIT(25)
 53#define TCAN4X5X_MCAN_IR_EW BIT(24)
 54#define TCAN4X5X_MCAN_IR_EP BIT(23)
 55#define TCAN4X5X_MCAN_IR_ELO BIT(22)
 56#define TCAN4X5X_MCAN_IR_BEU BIT(21)
 57#define TCAN4X5X_MCAN_IR_BEC BIT(20)
 58#define TCAN4X5X_MCAN_IR_DRX BIT(19)
 59#define TCAN4X5X_MCAN_IR_TOO BIT(18)
 60#define TCAN4X5X_MCAN_IR_MRAF BIT(17)
 61#define TCAN4X5X_MCAN_IR_TSW BIT(16)
 62#define TCAN4X5X_MCAN_IR_TEFL BIT(15)
 63#define TCAN4X5X_MCAN_IR_TEFF BIT(14)
 64#define TCAN4X5X_MCAN_IR_TEFW BIT(13)
 65#define TCAN4X5X_MCAN_IR_TEFN BIT(12)
 66#define TCAN4X5X_MCAN_IR_TFE BIT(11)
 67#define TCAN4X5X_MCAN_IR_TCF BIT(10)
 68#define TCAN4X5X_MCAN_IR_TC BIT(9)
 69#define TCAN4X5X_MCAN_IR_HPM BIT(8)
 70#define TCAN4X5X_MCAN_IR_RF1L BIT(7)
 71#define TCAN4X5X_MCAN_IR_RF1F BIT(6)
 72#define TCAN4X5X_MCAN_IR_RF1W BIT(5)
 73#define TCAN4X5X_MCAN_IR_RF1N BIT(4)
 74#define TCAN4X5X_MCAN_IR_RF0L BIT(3)
 75#define TCAN4X5X_MCAN_IR_RF0F BIT(2)
 76#define TCAN4X5X_MCAN_IR_RF0W BIT(1)
 77#define TCAN4X5X_MCAN_IR_RF0N BIT(0)
 78#define TCAN4X5X_ENABLE_MCAN_INT \
 79	(TCAN4X5X_MCAN_IR_TC | TCAN4X5X_MCAN_IR_RF0N | \
 80	 TCAN4X5X_MCAN_IR_RF1N | TCAN4X5X_MCAN_IR_RF0F | \
 81	 TCAN4X5X_MCAN_IR_RF1F)
 82
 83#define TCAN4X5X_MRAM_START 0x8000
 84#define TCAN4X5X_MRAM_SIZE 0x800
 85#define TCAN4X5X_MCAN_OFFSET 0x1000
 86
 87#define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
 88#define TCAN4X5X_SET_ALL_INT 0xffffffff
 89
 90#define TCAN4X5X_MODE_SEL_MASK (BIT(7) | BIT(6))
 91#define TCAN4X5X_MODE_SLEEP 0x00
 92#define TCAN4X5X_MODE_STANDBY BIT(6)
 93#define TCAN4X5X_MODE_NORMAL BIT(7)
 94
 95#define TCAN4X5X_DISABLE_WAKE_MSK	(BIT(31) | BIT(30))
 96#define TCAN4X5X_DISABLE_INH_MSK	BIT(9)
 97
 98#define TCAN4X5X_SW_RESET BIT(2)
 99
100#define TCAN4X5X_MCAN_CONFIGURED BIT(5)
101#define TCAN4X5X_WATCHDOG_EN BIT(3)
102#define TCAN4X5X_WD_60_MS_TIMER 0
103#define TCAN4X5X_WD_600_MS_TIMER BIT(28)
104#define TCAN4X5X_WD_3_S_TIMER BIT(29)
105#define TCAN4X5X_WD_6_S_TIMER (BIT(28) | BIT(29))
106
107struct tcan4x5x_version_info {
108	const char *name;
109	u32 id2_register;
110
111	bool has_wake_pin;
112	bool has_state_pin;
113};
114
115enum {
116	TCAN4552 = 0,
117	TCAN4553,
118	TCAN4X5X,
119};
120
121static const struct tcan4x5x_version_info tcan4x5x_versions[] = {
122	[TCAN4552] = {
123		.name = "4552",
124		.id2_register = 0x32353534,
125	},
126	[TCAN4553] = {
127		.name = "4553",
128		.id2_register = 0x33353534,
129	},
130	/* generic version with no id2_register at the end */
131	[TCAN4X5X] = {
132		.name = "generic",
133		.has_wake_pin = true,
134		.has_state_pin = true,
135	},
136};
137
138static inline struct tcan4x5x_priv *cdev_to_priv(struct m_can_classdev *cdev)
139{
140	return container_of(cdev, struct tcan4x5x_priv, cdev);
141}
142
143static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
144{
145	int wake_state = 0;
146
147	if (priv->device_state_gpio)
148		wake_state = gpiod_get_value(priv->device_state_gpio);
149
150	if (priv->device_wake_gpio && wake_state) {
151		gpiod_set_value(priv->device_wake_gpio, 0);
152		usleep_range(5, 50);
153		gpiod_set_value(priv->device_wake_gpio, 1);
154	}
155}
156
157static int tcan4x5x_reset(struct tcan4x5x_priv *priv)
158{
159	int ret = 0;
160
161	if (priv->reset_gpio) {
162		gpiod_set_value(priv->reset_gpio, 1);
163
164		/* tpulse_width minimum 30us */
165		usleep_range(30, 100);
166		gpiod_set_value(priv->reset_gpio, 0);
167	} else {
168		ret = regmap_write(priv->regmap, TCAN4X5X_CONFIG,
169				   TCAN4X5X_SW_RESET);
170		if (ret)
171			return ret;
172	}
173
174	usleep_range(700, 1000);
175
176	return ret;
177}
178
179static u32 tcan4x5x_read_reg(struct m_can_classdev *cdev, int reg)
180{
181	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
182	u32 val;
183
184	regmap_read(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, &val);
185
186	return val;
187}
188
189static int tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset,
190			      void *val, size_t val_count)
191{
192	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
193
194	return regmap_bulk_read(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val, val_count);
195}
196
197static int tcan4x5x_write_reg(struct m_can_classdev *cdev, int reg, int val)
198{
199	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
200
201	return regmap_write(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, val);
202}
203
204static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
205			       int addr_offset, const void *val, size_t val_count)
206{
207	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
208
209	return regmap_bulk_write(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val, val_count);
210}
211
212static int tcan4x5x_power_enable(struct regulator *reg, int enable)
213{
214	if (IS_ERR_OR_NULL(reg))
215		return 0;
216
217	if (enable)
218		return regulator_enable(reg);
219	else
220		return regulator_disable(reg);
221}
222
223static int tcan4x5x_write_tcan_reg(struct m_can_classdev *cdev,
224				   int reg, int val)
225{
226	struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
227
228	return regmap_write(priv->regmap, reg, val);
229}
230
231static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
232{
233	int ret;
234
235	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_STATUS,
236				      TCAN4X5X_CLEAR_ALL_INT);
237	if (ret)
238		return ret;
239
240	return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
241				       TCAN4X5X_CLEAR_ALL_INT);
242}
243
244static int tcan4x5x_init(struct m_can_classdev *cdev)
245{
246	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
247	int ret;
248
249	tcan4x5x_check_wake(tcan4x5x);
250
251	ret = tcan4x5x_clear_interrupts(cdev);
252	if (ret)
253		return ret;
254
255	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_EN,
256				      TCAN4X5X_ENABLE_TCAN_INT);
257	if (ret)
258		return ret;
259
260	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS_MASK,
261				      TCAN4X5X_CLEAR_ALL_INT);
262	if (ret)
263		return ret;
264
265	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
266				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
267	if (ret)
268		return ret;
269
270	return ret;
271}
272
273static int tcan4x5x_disable_wake(struct m_can_classdev *cdev)
274{
275	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
276
277	return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
278				  TCAN4X5X_DISABLE_WAKE_MSK, 0x00);
279}
280
281static int tcan4x5x_disable_state(struct m_can_classdev *cdev)
282{
283	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
284
285	return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
286				  TCAN4X5X_DISABLE_INH_MSK, 0x01);
287}
288
289static const struct tcan4x5x_version_info
290*tcan4x5x_find_version(struct tcan4x5x_priv *priv)
291{
292	u32 val;
293	int ret;
294
295	ret = regmap_read(priv->regmap, TCAN4X5X_DEV_ID1, &val);
296	if (ret)
297		return ERR_PTR(ret);
298
299	if (val != TCAN4X5X_DEV_ID1_TCAN) {
300		dev_err(&priv->spi->dev, "Not a tcan device %x\n", val);
301		return ERR_PTR(-ENODEV);
302	}
303
304	ret = regmap_read(priv->regmap, TCAN4X5X_DEV_ID2, &val);
305	if (ret)
306		return ERR_PTR(ret);
307
308	for (int i = 0; i != ARRAY_SIZE(tcan4x5x_versions); ++i) {
309		const struct tcan4x5x_version_info *vinfo = &tcan4x5x_versions[i];
310
311		if (!vinfo->id2_register || val == vinfo->id2_register) {
312			dev_info(&priv->spi->dev, "Detected TCAN device version %s\n",
313				 vinfo->name);
314			return vinfo;
315		}
316	}
317
318	return &tcan4x5x_versions[TCAN4X5X];
319}
320
321static int tcan4x5x_get_gpios(struct m_can_classdev *cdev,
322			      const struct tcan4x5x_version_info *version_info)
323{
324	struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
325	int ret;
326
327	if (version_info->has_wake_pin) {
328		tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
329							    GPIOD_OUT_HIGH);
330		if (IS_ERR(tcan4x5x->device_wake_gpio)) {
331			if (PTR_ERR(tcan4x5x->device_wake_gpio) == -EPROBE_DEFER)
332				return -EPROBE_DEFER;
333
334			tcan4x5x_disable_wake(cdev);
335		}
336	}
337
338	tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
339						       GPIOD_OUT_LOW);
340	if (IS_ERR(tcan4x5x->reset_gpio))
341		tcan4x5x->reset_gpio = NULL;
342
343	ret = tcan4x5x_reset(tcan4x5x);
344	if (ret)
345		return ret;
346
347	if (version_info->has_state_pin) {
348		tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
349								      "device-state",
350								      GPIOD_IN);
351		if (IS_ERR(tcan4x5x->device_state_gpio)) {
352			tcan4x5x->device_state_gpio = NULL;
353			tcan4x5x_disable_state(cdev);
354		}
355	}
356
357	return 0;
358}
359
360static struct m_can_ops tcan4x5x_ops = {
361	.init = tcan4x5x_init,
362	.read_reg = tcan4x5x_read_reg,
363	.write_reg = tcan4x5x_write_reg,
364	.write_fifo = tcan4x5x_write_fifo,
365	.read_fifo = tcan4x5x_read_fifo,
366	.clear_interrupts = tcan4x5x_clear_interrupts,
367};
368
369static int tcan4x5x_can_probe(struct spi_device *spi)
370{
371	const struct tcan4x5x_version_info *version_info;
372	struct tcan4x5x_priv *priv;
373	struct m_can_classdev *mcan_class;
374	int freq, ret;
375
376	mcan_class = m_can_class_allocate_dev(&spi->dev,
377					      sizeof(struct tcan4x5x_priv));
378	if (!mcan_class)
379		return -ENOMEM;
380
381	ret = m_can_check_mram_cfg(mcan_class, TCAN4X5X_MRAM_SIZE);
382	if (ret)
383		goto out_m_can_class_free_dev;
384
385	priv = cdev_to_priv(mcan_class);
386
387	priv->power = devm_regulator_get_optional(&spi->dev, "vsup");
388	if (PTR_ERR(priv->power) == -EPROBE_DEFER) {
389		ret = -EPROBE_DEFER;
390		goto out_m_can_class_free_dev;
391	} else {
392		priv->power = NULL;
393	}
394
395	m_can_class_get_clocks(mcan_class);
396	if (IS_ERR(mcan_class->cclk)) {
397		dev_err(&spi->dev, "no CAN clock source defined\n");
398		freq = TCAN4X5X_EXT_CLK_DEF;
399	} else {
400		freq = clk_get_rate(mcan_class->cclk);
401	}
402
403	/* Sanity check */
404	if (freq < 20000000 || freq > TCAN4X5X_EXT_CLK_DEF) {
405		dev_err(&spi->dev, "Clock frequency is out of supported range %d\n",
406			freq);
407		ret = -ERANGE;
408		goto out_m_can_class_free_dev;
409	}
410
411	priv->spi = spi;
412
413	mcan_class->pm_clock_support = 0;
414	mcan_class->can.clock.freq = freq;
415	mcan_class->dev = &spi->dev;
416	mcan_class->ops = &tcan4x5x_ops;
417	mcan_class->is_peripheral = true;
418	mcan_class->net->irq = spi->irq;
419
420	spi_set_drvdata(spi, priv);
421
422	/* Configure the SPI bus */
423	spi->bits_per_word = 8;
424	ret = spi_setup(spi);
425	if (ret) {
426		dev_err(&spi->dev, "SPI setup failed %pe\n", ERR_PTR(ret));
427		goto out_m_can_class_free_dev;
428	}
429
430	ret = tcan4x5x_regmap_init(priv);
431	if (ret) {
432		dev_err(&spi->dev, "regmap init failed %pe\n", ERR_PTR(ret));
433		goto out_m_can_class_free_dev;
434	}
435
436	ret = tcan4x5x_power_enable(priv->power, 1);
437	if (ret) {
438		dev_err(&spi->dev, "Enabling regulator failed %pe\n",
439			ERR_PTR(ret));
440		goto out_m_can_class_free_dev;
441	}
442
443	version_info = tcan4x5x_find_version(priv);
444	if (IS_ERR(version_info)) {
445		ret = PTR_ERR(version_info);
446		goto out_power;
447	}
448
449	ret = tcan4x5x_get_gpios(mcan_class, version_info);
450	if (ret) {
451		dev_err(&spi->dev, "Getting gpios failed %pe\n", ERR_PTR(ret));
452		goto out_power;
453	}
454
455	ret = tcan4x5x_init(mcan_class);
456	if (ret) {
457		dev_err(&spi->dev, "tcan initialization failed %pe\n",
458			ERR_PTR(ret));
459		goto out_power;
460	}
461
462	ret = m_can_class_register(mcan_class);
463	if (ret) {
464		dev_err(&spi->dev, "Failed registering m_can device %pe\n",
465			ERR_PTR(ret));
466		goto out_power;
467	}
468
469	netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
470	return 0;
471
472out_power:
473	tcan4x5x_power_enable(priv->power, 0);
474 out_m_can_class_free_dev:
475	m_can_class_free_dev(mcan_class->net);
476	return ret;
477}
478
479static void tcan4x5x_can_remove(struct spi_device *spi)
480{
481	struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
482
483	m_can_class_unregister(&priv->cdev);
484
485	tcan4x5x_power_enable(priv->power, 0);
486
487	m_can_class_free_dev(priv->cdev.net);
488}
489
490static const struct of_device_id tcan4x5x_of_match[] = {
491	{
492		.compatible = "ti,tcan4x5x",
493	}, {
494		/* sentinel */
495	},
496};
497MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);
498
499static const struct spi_device_id tcan4x5x_id_table[] = {
500	{
501		.name = "tcan4x5x",
502	}, {
503		/* sentinel */
504	},
505};
506MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);
507
508static struct spi_driver tcan4x5x_can_driver = {
509	.driver = {
510		.name = KBUILD_MODNAME,
511		.of_match_table = tcan4x5x_of_match,
512		.pm = NULL,
513	},
514	.id_table = tcan4x5x_id_table,
515	.probe = tcan4x5x_can_probe,
516	.remove = tcan4x5x_can_remove,
517};
518module_spi_driver(tcan4x5x_can_driver);
519
520MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
521MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
522MODULE_LICENSE("GPL v2");