serial-multi-instantiate.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Serial multi-instantiate driver, pseudo driver to instantiate multiple
  4 * client devices from a single fwnode.
  5 *
  6 * Copyright 2018 Hans de Goede <hdegoede@redhat.com>
  7 */
  8
  9#include <linux/acpi.h>
 10#include <linux/bits.h>
 11#include <linux/i2c.h>
 12#include <linux/interrupt.h>
 13#include <linux/kernel.h>
 14#include <linux/module.h>
 15#include <linux/platform_device.h>
 16#include <linux/property.h>
 17#include <linux/spi/spi.h>
 18#include <linux/types.h>
 19
 20#define IRQ_RESOURCE_TYPE	GENMASK(1, 0)
 21#define IRQ_RESOURCE_NONE	0
 22#define IRQ_RESOURCE_GPIO	1
 23#define IRQ_RESOURCE_APIC	2
 24#define IRQ_RESOURCE_AUTO   3
 25#define IRQ_RESOURCE_OPT	BIT(2)
 26
 27enum smi_bus_type {
 28	SMI_I2C,
 29	SMI_SPI,
 30	SMI_AUTO_DETECT,
 31};
 32
 33struct smi_instance {
 34	const char *type;
 35	unsigned int flags;
 36	int irq_idx;
 37};
 38
 39struct smi_node {
 40	enum smi_bus_type bus_type;
 41	struct smi_instance instances[];
 42};
 43
 44struct smi {
 45	int i2c_num;
 46	int spi_num;
 47	struct i2c_client **i2c_devs;
 48	struct spi_device **spi_devs;
 49};
 50
 51static int smi_get_irq(struct platform_device *pdev, struct acpi_device *adev,
 52		       const struct smi_instance *inst)
 53{
 54	int ret;
 55
 56	switch (inst->flags & IRQ_RESOURCE_TYPE) {
 57	case IRQ_RESOURCE_AUTO:
 58		ret = acpi_dev_gpio_irq_get(adev, inst->irq_idx);
 59		if (ret > 0) {
 60			dev_dbg(&pdev->dev, "Using gpio irq\n");
 61			break;
 62		}
 63		ret = platform_get_irq(pdev, inst->irq_idx);
 64		if (ret > 0) {
 65			dev_dbg(&pdev->dev, "Using platform irq\n");
 66			break;
 67		}
 68		if (inst->flags & IRQ_RESOURCE_OPT) {
 69			dev_dbg(&pdev->dev, "No irq\n");
 70			return 0;
 71		}
 72		break;
 73	case IRQ_RESOURCE_GPIO:
 74		ret = acpi_dev_gpio_irq_get(adev, inst->irq_idx);
 75		break;
 76	case IRQ_RESOURCE_APIC:
 77		ret = platform_get_irq(pdev, inst->irq_idx);
 78		break;
 79	default:
 80		return 0;
 81	}
 82	if (ret < 0)
 83		return dev_err_probe(&pdev->dev, ret, "Error requesting irq at index %d\n",
 84				     inst->irq_idx);
 85
 86	return ret;
 87}
 88
 89static void smi_devs_unregister(struct smi *smi)
 90{
 91#if IS_REACHABLE(CONFIG_I2C)
 92	while (smi->i2c_num--)
 93		i2c_unregister_device(smi->i2c_devs[smi->i2c_num]);
 94#endif
 95
 96	if (IS_REACHABLE(CONFIG_SPI)) {
 97		while (smi->spi_num--)
 98			spi_unregister_device(smi->spi_devs[smi->spi_num]);
 99	}
100}
101
102/**
103 * smi_spi_probe - Instantiate multiple SPI devices from inst array
104 * @pdev:	Platform device
105 * @smi:	Internal struct for Serial multi instantiate driver
106 * @inst_array:	Array of instances to probe
107 *
108 * Returns the number of SPI devices instantiate, Zero if none is found or a negative error code.
109 */
110static int smi_spi_probe(struct platform_device *pdev, struct smi *smi,
111			 const struct smi_instance *inst_array)
112{
113	struct device *dev = &pdev->dev;
114	struct acpi_device *adev = ACPI_COMPANION(dev);
115	struct spi_controller *ctlr;
116	struct spi_device *spi_dev;
117	char name[50];
118	int i, ret, count;
119
120	ret = acpi_spi_count_resources(adev);
121	if (ret < 0)
122		return ret;
123	if (!ret)
124		return -ENOENT;
125
126	count = ret;
127
128	smi->spi_devs = devm_kcalloc(dev, count, sizeof(*smi->spi_devs), GFP_KERNEL);
129	if (!smi->spi_devs)
130		return -ENOMEM;
131
132	for (i = 0; i < count && inst_array[i].type; i++) {
133
134		spi_dev = acpi_spi_device_alloc(NULL, adev, i);
135		if (IS_ERR(spi_dev)) {
136			ret = dev_err_probe(dev, PTR_ERR(spi_dev), "failed to allocate SPI device %s from ACPI\n",
137					    dev_name(&adev->dev));
138			goto error;
139		}
140
141		ctlr = spi_dev->controller;
142
143		strscpy(spi_dev->modalias, inst_array[i].type);
144
145		ret = smi_get_irq(pdev, adev, &inst_array[i]);
146		if (ret < 0) {
147			spi_dev_put(spi_dev);
148			goto error;
149		}
150		spi_dev->irq = ret;
151
152		snprintf(name, sizeof(name), "%s-%s-%s.%d", dev_name(&ctlr->dev), dev_name(dev),
153			 inst_array[i].type, i);
154		spi_dev->dev.init_name = name;
155
156		ret = spi_add_device(spi_dev);
157		if (ret) {
158			dev_err_probe(&ctlr->dev, ret, "failed to add SPI device %s from ACPI\n",
159				      dev_name(&adev->dev));
160			spi_dev_put(spi_dev);
161			goto error;
162		}
163
164		dev_dbg(dev, "SPI device %s using chip select %u", name,
165			spi_get_chipselect(spi_dev, 0));
166
167		smi->spi_devs[i] = spi_dev;
168		smi->spi_num++;
169	}
170
171	if (smi->spi_num < count) {
172		dev_dbg(dev, "Error finding driver, idx %d\n", i);
173		ret = -ENODEV;
174		goto error;
175	}
176
177	dev_info(dev, "Instantiated %d SPI devices.\n", smi->spi_num);
178
179	return 0;
180error:
181	smi_devs_unregister(smi);
182
183	return ret;
184}
185
186/**
187 * smi_i2c_probe - Instantiate multiple I2C devices from inst array
188 * @pdev:	Platform device
189 * @smi:	Internal struct for Serial multi instantiate driver
190 * @inst_array:	Array of instances to probe
191 *
192 * Returns the number of I2C devices instantiate, Zero if none is found or a negative error code.
193 */
194static int smi_i2c_probe(struct platform_device *pdev, struct smi *smi,
195			 const struct smi_instance *inst_array)
196{
197	struct i2c_board_info board_info = {};
198	struct device *dev = &pdev->dev;
199	struct acpi_device *adev = ACPI_COMPANION(dev);
200	char name[32];
201	int i, ret, count;
202
203	ret = i2c_acpi_client_count(adev);
204	if (ret < 0)
205		return ret;
206	if (!ret)
207		return -ENOENT;
208
209	count = ret;
210
211	smi->i2c_devs = devm_kcalloc(dev, count, sizeof(*smi->i2c_devs), GFP_KERNEL);
212	if (!smi->i2c_devs)
213		return -ENOMEM;
214
215	for (i = 0; i < count && inst_array[i].type; i++) {
216		memset(&board_info, 0, sizeof(board_info));
217		strscpy(board_info.type, inst_array[i].type);
218		snprintf(name, sizeof(name), "%s-%s.%d", dev_name(dev), inst_array[i].type, i);
219		board_info.dev_name = name;
220
221		ret = smi_get_irq(pdev, adev, &inst_array[i]);
222		if (ret < 0)
223			goto error;
224		board_info.irq = ret;
225
226		smi->i2c_devs[i] = i2c_acpi_new_device(dev, i, &board_info);
227		if (IS_ERR(smi->i2c_devs[i])) {
228			ret = dev_err_probe(dev, PTR_ERR(smi->i2c_devs[i]),
229					    "Error creating i2c-client, idx %d\n", i);
230			goto error;
231		}
232		smi->i2c_num++;
233	}
234	if (smi->i2c_num < count) {
235		dev_dbg(dev, "Error finding driver, idx %d\n", i);
236		ret = -ENODEV;
237		goto error;
238	}
239
240	dev_info(dev, "Instantiated %d I2C devices.\n", smi->i2c_num);
241
242	return 0;
243error:
244	smi_devs_unregister(smi);
245
246	return ret;
247}
248
249static int smi_probe(struct platform_device *pdev)
250{
251	struct device *dev = &pdev->dev;
252	const struct smi_node *node;
253	struct smi *smi;
254	int ret;
255
256	node = device_get_match_data(dev);
257	if (!node) {
258		dev_dbg(dev, "Error ACPI match data is missing\n");
259		return -ENODEV;
260	}
261
262	smi = devm_kzalloc(dev, sizeof(*smi), GFP_KERNEL);
263	if (!smi)
264		return -ENOMEM;
265
266	platform_set_drvdata(pdev, smi);
267
268	switch (node->bus_type) {
269	case SMI_I2C:
270		if (IS_REACHABLE(CONFIG_I2C))
271			return smi_i2c_probe(pdev, smi, node->instances);
272
273		return -ENODEV;
274	case SMI_SPI:
275		if (IS_REACHABLE(CONFIG_SPI))
276			return smi_spi_probe(pdev, smi, node->instances);
277
278		return -ENODEV;
279	case SMI_AUTO_DETECT:
280		/*
281		 * For backwards-compatibility with the existing nodes I2C
282		 * is checked first and if such entries are found ONLY I2C
283		 * devices are created. Since some existing nodes that were
284		 * already handled by this driver could also contain unrelated
285		 * SpiSerialBus nodes that were previously ignored, and this
286		 * preserves that behavior.
287		 */
288		if (IS_REACHABLE(CONFIG_I2C)) {
289			ret = smi_i2c_probe(pdev, smi, node->instances);
290			if (ret != -ENOENT)
291				return ret;
292		}
293
294		if (IS_REACHABLE(CONFIG_SPI))
295			return smi_spi_probe(pdev, smi, node->instances);
296
297		return -ENODEV;
298	default:
299		return -EINVAL;
300	}
301}
302
303static void smi_remove(struct platform_device *pdev)
304{
305	struct smi *smi = platform_get_drvdata(pdev);
306
307	smi_devs_unregister(smi);
308}
309
310static const struct smi_node bsg1160_data = {
311	.instances = {
312		{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
313		{ "bmc150_magn" },
314		{ "bmg160" },
315		{}
316	},
317	.bus_type = SMI_I2C,
318};
319
320static const struct smi_node bsg2150_data = {
321	.instances = {
322		{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
323		{ "bmc150_magn" },
324		/* The resources describe a 3th client, but it is not really there. */
325		{ "bsg2150_dummy_dev" },
326		{}
327	},
328	.bus_type = SMI_I2C,
329};
330
331static const struct smi_node int3515_data = {
332	.instances = {
333		{ "tps6598x", IRQ_RESOURCE_APIC, 0 },
334		{ "tps6598x", IRQ_RESOURCE_APIC, 1 },
335		{ "tps6598x", IRQ_RESOURCE_APIC, 2 },
336		{ "tps6598x", IRQ_RESOURCE_APIC, 3 },
337		{}
338	},
339	.bus_type = SMI_I2C,
340};
341
342static const struct smi_node cs35l41_hda = {
343	.instances = {
344		{ "cs35l41-hda", IRQ_RESOURCE_AUTO, 0 },
345		{ "cs35l41-hda", IRQ_RESOURCE_AUTO, 0 },
346		{ "cs35l41-hda", IRQ_RESOURCE_AUTO, 0 },
347		{ "cs35l41-hda", IRQ_RESOURCE_AUTO, 0 },
348		{}
349	},
350	.bus_type = SMI_AUTO_DETECT,
351};
352
353static const struct smi_node cs35l54_hda = {
354	.instances = {
355		{ "cs35l54-hda", IRQ_RESOURCE_AUTO, 0 },
356		{ "cs35l54-hda", IRQ_RESOURCE_AUTO, 0 },
357		{ "cs35l54-hda", IRQ_RESOURCE_AUTO, 0 },
358		{ "cs35l54-hda", IRQ_RESOURCE_AUTO, 0 },
359		/* a 5th entry is an alias address, not a real device */
360		{ "cs35l54-hda_dummy_dev" },
361		{}
362	},
363	.bus_type = SMI_AUTO_DETECT,
364};
365
366static const struct smi_node cs35l56_hda = {
367	.instances = {
368		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
369		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
370		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
371		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
372		/* a 5th entry is an alias address, not a real device */
373		{ "cs35l56-hda_dummy_dev" },
374		{}
375	},
376	.bus_type = SMI_AUTO_DETECT,
377};
378
379static const struct smi_node cs35l57_hda = {
380	.instances = {
381		{ "cs35l57-hda", IRQ_RESOURCE_AUTO, 0 },
382		{ "cs35l57-hda", IRQ_RESOURCE_AUTO, 0 },
383		{ "cs35l57-hda", IRQ_RESOURCE_AUTO, 0 },
384		{ "cs35l57-hda", IRQ_RESOURCE_AUTO, 0 },
385		/* a 5th entry is an alias address, not a real device */
386		{ "cs35l57-hda_dummy_dev" },
387		{}
388	},
389	.bus_type = SMI_AUTO_DETECT,
390};
391
392static const struct smi_node tas2781_hda = {
393	.instances = {
394		{ "tas2781-hda", IRQ_RESOURCE_AUTO | IRQ_RESOURCE_OPT, 0 },
395		{ "tas2781-hda", IRQ_RESOURCE_AUTO | IRQ_RESOURCE_OPT, 0 },
396		{ "tas2781-hda", IRQ_RESOURCE_AUTO | IRQ_RESOURCE_OPT, 0 },
397		{ "tas2781-hda", IRQ_RESOURCE_AUTO | IRQ_RESOURCE_OPT, 0 },
398		{}
399	},
400	.bus_type = SMI_AUTO_DETECT,
401};
402
403/*
404 * Note new device-ids must also be added to ignore_serial_bus_ids in
405 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
406 */
407static const struct acpi_device_id smi_acpi_ids[] = {
408	{ "BSG1160", (unsigned long)&bsg1160_data },
409	{ "BSG2150", (unsigned long)&bsg2150_data },
410	{ "CSC3551", (unsigned long)&cs35l41_hda },
411	{ "CSC3554", (unsigned long)&cs35l54_hda },
412	{ "CSC3556", (unsigned long)&cs35l56_hda },
413	{ "CSC3557", (unsigned long)&cs35l57_hda },
414	{ "INT3515", (unsigned long)&int3515_data },
415	{ "TXNW2781", (unsigned long)&tas2781_hda },
416	/* Non-conforming _HID for Cirrus Logic already released */
417	{ "CLSA0100", (unsigned long)&cs35l41_hda },
418	{ "CLSA0101", (unsigned long)&cs35l41_hda },
419	{ }
420};
421MODULE_DEVICE_TABLE(acpi, smi_acpi_ids);
422
423static struct platform_driver smi_driver = {
424	.driver	= {
425		.name = "Serial bus multi instantiate pseudo device driver",
426		.acpi_match_table = smi_acpi_ids,
427	},
428	.probe = smi_probe,
429	.remove = smi_remove,
430};
431module_platform_driver(smi_driver);
432
433MODULE_DESCRIPTION("Serial multi instantiate pseudo device driver");
434MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
435MODULE_LICENSE("GPL");