xref: /linux/drivers/platform/x86/serial-multi-instantiate.c (revision 9d588a1140b9ae211581a7a154d0b806d8cd8238)
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 
27 enum smi_bus_type {
28 	SMI_I2C,
29 	SMI_SPI,
30 	SMI_AUTO_DETECT,
31 };
32 
33 struct smi_instance {
34 	const char *type;
35 	unsigned int flags;
36 	int irq_idx;
37 };
38 
39 struct smi_node {
40 	enum smi_bus_type bus_type;
41 	struct smi_instance instances[];
42 };
43 
44 struct smi {
45 	int i2c_num;
46 	int spi_num;
47 	struct i2c_client **i2c_devs;
48 	struct spi_device **spi_devs;
49 };
50 
smi_get_irq(struct platform_device * pdev,struct acpi_device * adev,const struct smi_instance * inst)51 static 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 
smi_devs_unregister(struct smi * smi)89 static 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  */
smi_spi_probe(struct platform_device * pdev,struct smi * smi,const struct smi_instance * inst_array)110 static 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;
180 error:
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  */
smi_i2c_probe(struct platform_device * pdev,struct smi * smi,const struct smi_instance * inst_array)194 static 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;
243 error:
244 	smi_devs_unregister(smi);
245 
246 	return ret;
247 }
248 
smi_probe(struct platform_device * pdev)249 static 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 
smi_remove(struct platform_device * pdev)303 static void smi_remove(struct platform_device *pdev)
304 {
305 	struct smi *smi = platform_get_drvdata(pdev);
306 
307 	smi_devs_unregister(smi);
308 }
309 
310 static 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 
320 static 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 
331 static 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 
342 static 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 
353 static 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 
366 static 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 
379 static 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 
392 static 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  */
407 static 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 };
421 MODULE_DEVICE_TABLE(acpi, smi_acpi_ids);
422 
423 static 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 };
431 module_platform_driver(smi_driver);
432 
433 MODULE_DESCRIPTION("Serial multi instantiate pseudo device driver");
434 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
435 MODULE_LICENSE("GPL");
436