Linux Audio

Check our new training course

Embedded Linux training

Mar 10-20, 2025, special US time zones
Register
Loading...
  1// SPDX-License-Identifier: GPL-2.0
  2//
  3// CS42L43 SPI Controller Driver
  4//
  5// Copyright (C) 2022-2023 Cirrus Logic, Inc. and
  6//                         Cirrus Logic International Semiconductor Ltd.
  7
  8#include <linux/acpi.h>
  9#include <linux/array_size.h>
 10#include <linux/bits.h>
 11#include <linux/bitfield.h>
 12#include <linux/cleanup.h>
 13#include <linux/device.h>
 14#include <linux/errno.h>
 15#include <linux/gpio/consumer.h>
 16#include <linux/gpio/machine.h>
 17#include <linux/gpio/property.h>
 18#include <linux/mfd/cs42l43.h>
 19#include <linux/mfd/cs42l43-regs.h>
 20#include <linux/mod_devicetable.h>
 21#include <linux/module.h>
 22#include <linux/of.h>
 23#include <linux/platform_device.h>
 24#include <linux/pm_runtime.h>
 25#include <linux/property.h>
 26#include <linux/regmap.h>
 27#include <linux/spi/spi.h>
 28#include <linux/units.h>
 29
 30#define CS42L43_FIFO_SIZE		16
 31#define CS42L43_SPI_ROOT_HZ		49152000
 32#define CS42L43_SPI_MAX_LENGTH		65532
 33
 34enum cs42l43_spi_cmd {
 35	CS42L43_WRITE,
 36	CS42L43_READ
 37};
 38
 39struct cs42l43_spi {
 40	struct device *dev;
 41	struct regmap *regmap;
 42	struct spi_controller *ctlr;
 43};
 44
 45static const unsigned int cs42l43_clock_divs[] = {
 46	2, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30
 47};
 48
 49static struct spi_board_info amp_info_template = {
 50	.modalias		= "cs35l56",
 51	.max_speed_hz		= 11 * HZ_PER_MHZ,
 52	.mode			= SPI_MODE_0,
 53};
 54
 55static const struct software_node cs42l43_gpiochip_swnode = {
 56	.name			= "cs42l43-pinctrl",
 57};
 58
 59static const struct software_node_ref_args cs42l43_cs_refs[] = {
 60	SOFTWARE_NODE_REFERENCE(&cs42l43_gpiochip_swnode, 0, GPIO_ACTIVE_LOW),
 61	SOFTWARE_NODE_REFERENCE(&swnode_gpio_undefined),
 62};
 63
 64static const struct property_entry cs42l43_cs_props[] = {
 65	PROPERTY_ENTRY_REF_ARRAY("cs-gpios", cs42l43_cs_refs),
 66	{}
 67};
 68
 69static int cs42l43_spi_tx(struct regmap *regmap, const u8 *buf, unsigned int len)
 70{
 71	const u8 *end = buf + len;
 72	u32 val = 0;
 73	int ret;
 74
 75	while (buf < end) {
 76		const u8 *block = min(buf + CS42L43_FIFO_SIZE, end);
 77
 78		while (buf < block) {
 79			const u8 *word = min(buf + sizeof(u32), block);
 80			int pad = (buf + sizeof(u32)) - word;
 81
 82			while (buf < word) {
 83				val >>= BITS_PER_BYTE;
 84				val |= FIELD_PREP(GENMASK(31, 24), *buf);
 85
 86				buf++;
 87			}
 88
 89			val >>= pad * BITS_PER_BYTE;
 90
 91			regmap_write(regmap, CS42L43_TX_DATA, val);
 92		}
 93
 94		regmap_write(regmap, CS42L43_TRAN_CONFIG8, CS42L43_SPI_TX_DONE_MASK);
 95
 96		ret = regmap_read_poll_timeout(regmap, CS42L43_TRAN_STATUS1,
 97					       val, (val & CS42L43_SPI_TX_REQUEST_MASK),
 98					       1000, 5000);
 99		if (ret)
100			return ret;
101	}
102
103	return 0;
104}
105
106static int cs42l43_spi_rx(struct regmap *regmap, u8 *buf, unsigned int len)
107{
108	u8 *end = buf + len;
109	u32 val;
110	int ret;
111
112	while (buf < end) {
113		u8 *block = min(buf + CS42L43_FIFO_SIZE, end);
114
115		ret = regmap_read_poll_timeout(regmap, CS42L43_TRAN_STATUS1,
116					       val, (val & CS42L43_SPI_RX_REQUEST_MASK),
117					       1000, 5000);
118		if (ret)
119			return ret;
120
121		while (buf < block) {
122			u8 *word = min(buf + sizeof(u32), block);
123
124			ret = regmap_read(regmap, CS42L43_RX_DATA, &val);
125			if (ret)
126				return ret;
127
128			while (buf < word) {
129				*buf = FIELD_GET(GENMASK(7, 0), val);
130
131				val >>= BITS_PER_BYTE;
132				buf++;
133			}
134		}
135
136		regmap_write(regmap, CS42L43_TRAN_CONFIG8, CS42L43_SPI_RX_DONE_MASK);
137	}
138
139	return 0;
140}
141
142static int cs42l43_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
143				struct spi_transfer *tfr)
144{
145	struct cs42l43_spi *priv = spi_controller_get_devdata(spi->controller);
146	int i, ret = -EINVAL;
147
148	for (i = 0; i < ARRAY_SIZE(cs42l43_clock_divs); i++) {
149		if (CS42L43_SPI_ROOT_HZ / cs42l43_clock_divs[i] <= tfr->speed_hz)
150			break;
151	}
152
153	if (i == ARRAY_SIZE(cs42l43_clock_divs))
154		return -EINVAL;
155
156	regmap_write(priv->regmap, CS42L43_SPI_CLK_CONFIG1, i);
157
158	if (tfr->tx_buf) {
159		regmap_write(priv->regmap, CS42L43_TRAN_CONFIG3, CS42L43_WRITE);
160		regmap_write(priv->regmap, CS42L43_TRAN_CONFIG4, tfr->len - 1);
161	} else if (tfr->rx_buf) {
162		regmap_write(priv->regmap, CS42L43_TRAN_CONFIG3, CS42L43_READ);
163		regmap_write(priv->regmap, CS42L43_TRAN_CONFIG5, tfr->len - 1);
164	}
165
166	regmap_write(priv->regmap, CS42L43_TRAN_CONFIG1, CS42L43_SPI_START_MASK);
167
168	if (tfr->tx_buf)
169		ret = cs42l43_spi_tx(priv->regmap, (const u8 *)tfr->tx_buf, tfr->len);
170	else if (tfr->rx_buf)
171		ret = cs42l43_spi_rx(priv->regmap, (u8 *)tfr->rx_buf, tfr->len);
172
173	return ret;
174}
175
176static void cs42l43_set_cs(struct spi_device *spi, bool is_high)
177{
178	struct cs42l43_spi *priv = spi_controller_get_devdata(spi->controller);
179
180	regmap_write(priv->regmap, CS42L43_SPI_CONFIG2, !is_high);
181}
182
183static int cs42l43_prepare_message(struct spi_controller *ctlr, struct spi_message *msg)
184{
185	struct cs42l43_spi *priv = spi_controller_get_devdata(ctlr);
186	struct spi_device *spi = msg->spi;
187	unsigned int spi_config1 = 0;
188
189	/* select another internal CS, which doesn't exist, so CS 0 is not used */
190	if (spi_get_csgpiod(spi, 0))
191		spi_config1 |= 1 << CS42L43_SPI_SS_SEL_SHIFT;
192	if (spi->mode & SPI_CPOL)
193		spi_config1 |= CS42L43_SPI_CPOL_MASK;
194	if (spi->mode & SPI_CPHA)
195		spi_config1 |= CS42L43_SPI_CPHA_MASK;
196	if (spi->mode & SPI_3WIRE)
197		spi_config1 |= CS42L43_SPI_THREE_WIRE_MASK;
198
199	regmap_write(priv->regmap, CS42L43_SPI_CONFIG1, spi_config1);
200
201	return 0;
202}
203
204static int cs42l43_prepare_transfer_hardware(struct spi_controller *ctlr)
205{
206	struct cs42l43_spi *priv = spi_controller_get_devdata(ctlr);
207	int ret;
208
209	ret = regmap_write(priv->regmap, CS42L43_BLOCK_EN2, CS42L43_SPI_MSTR_EN_MASK);
210	if (ret)
211		dev_err(priv->dev, "Failed to enable SPI controller: %d\n", ret);
212
213	return ret;
214}
215
216static int cs42l43_unprepare_transfer_hardware(struct spi_controller *ctlr)
217{
218	struct cs42l43_spi *priv = spi_controller_get_devdata(ctlr);
219	int ret;
220
221	ret = regmap_write(priv->regmap, CS42L43_BLOCK_EN2, 0);
222	if (ret)
223		dev_err(priv->dev, "Failed to disable SPI controller: %d\n", ret);
224
225	return ret;
226}
227
228static size_t cs42l43_spi_max_length(struct spi_device *spi)
229{
230	return CS42L43_SPI_MAX_LENGTH;
231}
232
233static int cs42l43_get_speaker_id_gpios(struct cs42l43_spi *priv, int *result)
234{
235	struct gpio_descs *descs;
236	u32 spkid;
237	int i, ret;
238
239	descs = gpiod_get_array_optional(priv->dev, "spk-id", GPIOD_IN);
240	if (IS_ERR_OR_NULL(descs))
241		return PTR_ERR(descs);
242
243	spkid = 0;
244	for (i = 0; i < descs->ndescs; i++) {
245		ret = gpiod_get_value_cansleep(descs->desc[i]);
246		if (ret < 0)
247			goto err;
248
249		spkid |= (ret << i);
250	}
251
252	dev_dbg(priv->dev, "spk-id-gpios = %d\n", spkid);
253	*result = spkid;
254err:
255	gpiod_put_array(descs);
256
257	return ret;
258}
259
260static struct fwnode_handle *cs42l43_find_xu_node(struct fwnode_handle *fwnode)
261{
262	static const u32 func_smart_amp = 0x1;
263	struct fwnode_handle *child_fwnode, *ext_fwnode;
264	u32 function;
265	int ret;
266
267	fwnode_for_each_child_node(fwnode, child_fwnode) {
268		acpi_handle handle = ACPI_HANDLE_FWNODE(child_fwnode);
269
270		ret = acpi_get_local_address(handle, &function);
271		if (ret || function != func_smart_amp)
272			continue;
273
274		ext_fwnode = fwnode_get_named_child_node(child_fwnode,
275				"mipi-sdca-function-expansion-subproperties");
276		if (!ext_fwnode)
277			continue;
278
279		fwnode_handle_put(child_fwnode);
280
281		return ext_fwnode;
282	}
283
284	return NULL;
285}
286
287static struct spi_board_info *cs42l43_create_bridge_amp(struct cs42l43_spi *priv,
288							const char * const name,
289							int cs, int spkid)
290{
291	struct property_entry *props = NULL;
292	struct software_node *swnode;
293	struct spi_board_info *info;
294
295	if (spkid >= 0) {
296		props = devm_kmalloc(priv->dev, sizeof(*props), GFP_KERNEL);
297		if (!props)
298			return NULL;
299
300		*props = PROPERTY_ENTRY_U32("cirrus,speaker-id", spkid);
301	}
302
303	swnode = devm_kmalloc(priv->dev, sizeof(*swnode), GFP_KERNEL);
304	if (!swnode)
305		return NULL;
306
307	*swnode = SOFTWARE_NODE(name, props, NULL);
308
309	info = devm_kmemdup(priv->dev, &amp_info_template,
310			    sizeof(amp_info_template), GFP_KERNEL);
311	if (!info)
312		return NULL;
313
314	info->chip_select = cs;
315	info->swnode = swnode;
316
317	return info;
318}
319
320static void cs42l43_release_of_node(void *data)
321{
322	fwnode_handle_put(data);
323}
324
325static void cs42l43_release_sw_node(void *data)
326{
327	software_node_unregister(&cs42l43_gpiochip_swnode);
328}
329
330static int cs42l43_spi_probe(struct platform_device *pdev)
331{
332	struct cs42l43 *cs42l43 = dev_get_drvdata(pdev->dev.parent);
333	struct cs42l43_spi *priv;
334	struct fwnode_handle *fwnode = dev_fwnode(cs42l43->dev);
335	struct fwnode_handle *xu_fwnode __free(fwnode_handle) = cs42l43_find_xu_node(fwnode);
336	int nsidecars = 0;
337	int spkid = -EINVAL;
338	int ret;
339
340	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
341	if (!priv)
342		return -ENOMEM;
343
344	priv->ctlr = devm_spi_alloc_host(&pdev->dev, sizeof(*priv->ctlr));
345	if (!priv->ctlr)
346		return -ENOMEM;
347
348	spi_controller_set_devdata(priv->ctlr, priv);
349
350	priv->dev = &pdev->dev;
351	priv->regmap = cs42l43->regmap;
352
353	priv->ctlr->prepare_message = cs42l43_prepare_message;
354	priv->ctlr->prepare_transfer_hardware = cs42l43_prepare_transfer_hardware;
355	priv->ctlr->unprepare_transfer_hardware = cs42l43_unprepare_transfer_hardware;
356	priv->ctlr->transfer_one = cs42l43_transfer_one;
357	priv->ctlr->set_cs = cs42l43_set_cs;
358	priv->ctlr->max_transfer_size = cs42l43_spi_max_length;
359	priv->ctlr->mode_bits = SPI_3WIRE | SPI_MODE_X_MASK;
360	priv->ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;
361	priv->ctlr->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16) |
362					 SPI_BPW_MASK(32);
363	priv->ctlr->min_speed_hz = CS42L43_SPI_ROOT_HZ /
364				   cs42l43_clock_divs[ARRAY_SIZE(cs42l43_clock_divs) - 1];
365	priv->ctlr->max_speed_hz = CS42L43_SPI_ROOT_HZ / cs42l43_clock_divs[0];
366	priv->ctlr->use_gpio_descriptors = true;
367	priv->ctlr->auto_runtime_pm = true;
368
369	ret = devm_pm_runtime_enable(priv->dev);
370	if (ret)
371		return ret;
372
373	pm_runtime_idle(priv->dev);
374
375	regmap_write(priv->regmap, CS42L43_TRAN_CONFIG6, CS42L43_FIFO_SIZE - 1);
376	regmap_write(priv->regmap, CS42L43_TRAN_CONFIG7, CS42L43_FIFO_SIZE - 1);
377
378	// Disable Watchdog timer and enable stall
379	regmap_write(priv->regmap, CS42L43_SPI_CONFIG3, 0);
380	regmap_write(priv->regmap, CS42L43_SPI_CONFIG4, CS42L43_SPI_STALL_ENA_MASK);
381
382	if (is_of_node(fwnode)) {
383		fwnode = fwnode_get_named_child_node(fwnode, "spi");
384		ret = devm_add_action_or_reset(priv->dev, cs42l43_release_of_node, fwnode);
385		if (ret)
386			return ret;
387	}
388
389	fwnode_property_read_u32(xu_fwnode, "01fa-sidecar-instances", &nsidecars);
390
391	if (nsidecars) {
392		ret = fwnode_property_read_u32(xu_fwnode, "01fa-spk-id-val", &spkid);
393		if (!ret) {
394			dev_dbg(priv->dev, "01fa-spk-id-val = %d\n", spkid);
395		} else if (ret != -EINVAL) {
396			return dev_err_probe(priv->dev, ret, "Failed to get spk-id-val\n");
397		} else {
398			ret = cs42l43_get_speaker_id_gpios(priv, &spkid);
399			if (ret < 0)
400				return dev_err_probe(priv->dev, ret,
401						     "Failed to get spk-id-gpios\n");
402		}
403
404		ret = software_node_register(&cs42l43_gpiochip_swnode);
405		if (ret)
406			return dev_err_probe(priv->dev, ret,
407					     "Failed to register gpio swnode\n");
408
409		ret = devm_add_action_or_reset(priv->dev, cs42l43_release_sw_node, NULL);
410		if (ret)
411			return ret;
412
413		ret = device_create_managed_software_node(&priv->ctlr->dev,
414							  cs42l43_cs_props, NULL);
415		if (ret)
416			return dev_err_probe(priv->dev, ret, "Failed to add swnode\n");
417	} else {
418		device_set_node(&priv->ctlr->dev, fwnode);
419	}
420
421	ret = devm_spi_register_controller(priv->dev, priv->ctlr);
422	if (ret)
423		return dev_err_probe(priv->dev, ret,
424				     "Failed to register SPI controller\n");
425
426	if (nsidecars) {
427		struct spi_board_info *ampl_info;
428		struct spi_board_info *ampr_info;
429
430		ampl_info = cs42l43_create_bridge_amp(priv, "cs35l56-left", 0, spkid);
431		if (!ampl_info)
432			return -ENOMEM;
433
434		ampr_info = cs42l43_create_bridge_amp(priv, "cs35l56-right", 1, spkid);
435		if (!ampr_info)
436			return -ENOMEM;
437
438		if (!spi_new_device(priv->ctlr, ampl_info))
439			return dev_err_probe(priv->dev, -ENODEV,
440					     "Failed to create left amp slave\n");
441
442		if (!spi_new_device(priv->ctlr, ampr_info))
443			return dev_err_probe(priv->dev, -ENODEV,
444					     "Failed to create right amp slave\n");
445	}
446
447	return 0;
448}
449
450static const struct platform_device_id cs42l43_spi_id_table[] = {
451	{ "cs42l43-spi", },
452	{}
453};
454MODULE_DEVICE_TABLE(platform, cs42l43_spi_id_table);
455
456static struct platform_driver cs42l43_spi_driver = {
457	.driver = {
458		.name	= "cs42l43-spi",
459	},
460	.probe		= cs42l43_spi_probe,
461	.id_table	= cs42l43_spi_id_table,
462};
463module_platform_driver(cs42l43_spi_driver);
464
465MODULE_IMPORT_NS("GPIO_SWNODE");
466MODULE_DESCRIPTION("CS42L43 SPI Driver");
467MODULE_AUTHOR("Lucas Tanure <tanureal@opensource.cirrus.com>");
468MODULE_AUTHOR("Maciej Strozek <mstrozek@opensource.cirrus.com>");
469MODULE_LICENSE("GPL");