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
 25enum smi_bus_type {
 26	SMI_I2C,
 27	SMI_SPI,
 28	SMI_AUTO_DETECT,
 29};
 30
 31struct smi_instance {
 32	const char *type;
 33	unsigned int flags;
 34	int irq_idx;
 35};
 36
 37struct smi_node {
 38	enum smi_bus_type bus_type;
 39	struct smi_instance instances[];
 40};
 41
 42struct smi {
 43	int i2c_num;
 44	int spi_num;
 45	struct i2c_client **i2c_devs;
 46	struct spi_device **spi_devs;
 47};
 48
 49static int smi_get_irq(struct platform_device *pdev, struct acpi_device *adev,
 50		       const struct smi_instance *inst)
 51{
 52	int ret;
 53
 54	switch (inst->flags & IRQ_RESOURCE_TYPE) {
 55	case IRQ_RESOURCE_GPIO:
 56		ret = acpi_dev_gpio_irq_get(adev, inst->irq_idx);
 57		break;
 58	case IRQ_RESOURCE_APIC:
 59		ret = platform_get_irq(pdev, inst->irq_idx);
 60		break;
 61	default:
 62		return 0;
 63	}
 64	if (ret < 0)
 65		return dev_err_probe(&pdev->dev, ret, "Error requesting irq at index %d\n",
 66				     inst->irq_idx);
 67
 68	return ret;
 69}
 70
 71static void smi_devs_unregister(struct smi *smi)
 72{
 73	while (smi->i2c_num--)
 74		i2c_unregister_device(smi->i2c_devs[smi->i2c_num]);
 75
 76	while (smi->spi_num--)
 77		spi_unregister_device(smi->spi_devs[smi->spi_num]);
 78}
 79
 80/**
 81 * smi_spi_probe - Instantiate multiple SPI devices from inst array
 82 * @pdev:	Platform device
 83 * @smi:	Internal struct for Serial multi instantiate driver
 84 * @inst_array:	Array of instances to probe
 85 *
 86 * Returns the number of SPI devices instantiate, Zero if none is found or a negative error code.
 87 */
 88static int smi_spi_probe(struct platform_device *pdev, struct smi *smi,
 89			 const struct smi_instance *inst_array)
 90{
 91	struct device *dev = &pdev->dev;
 92	struct acpi_device *adev = ACPI_COMPANION(dev);
 93	struct spi_controller *ctlr;
 94	struct spi_device *spi_dev;
 95	char name[50];
 96	int i, ret, count;
 97
 98	ret = acpi_spi_count_resources(adev);
 99	if (ret < 0)
100		return ret;
101	if (!ret)
102		return -ENOENT;
103
104	count = ret;
105
106	smi->spi_devs = devm_kcalloc(dev, count, sizeof(*smi->spi_devs), GFP_KERNEL);
107	if (!smi->spi_devs)
108		return -ENOMEM;
109
110	for (i = 0; i < count && inst_array[i].type; i++) {
111
112		spi_dev = acpi_spi_device_alloc(NULL, adev, i);
113		if (IS_ERR(spi_dev)) {
114			ret = dev_err_probe(dev, PTR_ERR(spi_dev), "failed to allocate SPI device %s from ACPI\n",
115					    dev_name(&adev->dev));
116			goto error;
117		}
118
119		ctlr = spi_dev->controller;
120
121		strscpy(spi_dev->modalias, inst_array[i].type, sizeof(spi_dev->modalias));
122
123		ret = smi_get_irq(pdev, adev, &inst_array[i]);
124		if (ret < 0) {
125			spi_dev_put(spi_dev);
126			goto error;
127		}
128		spi_dev->irq = ret;
129
130		snprintf(name, sizeof(name), "%s-%s-%s.%d", dev_name(&ctlr->dev), dev_name(dev),
131			 inst_array[i].type, i);
132		spi_dev->dev.init_name = name;
133
134		ret = spi_add_device(spi_dev);
135		if (ret) {
136			dev_err_probe(&ctlr->dev, ret, "failed to add SPI device %s from ACPI\n",
137				      dev_name(&adev->dev));
138			spi_dev_put(spi_dev);
139			goto error;
140		}
141
142		dev_dbg(dev, "SPI device %s using chip select %u", name, spi_dev->chip_select);
143
144		smi->spi_devs[i] = spi_dev;
145		smi->spi_num++;
146	}
147
148	if (smi->spi_num < count) {
149		dev_dbg(dev, "Error finding driver, idx %d\n", i);
150		ret = -ENODEV;
151		goto error;
152	}
153
154	dev_info(dev, "Instantiated %d SPI devices.\n", smi->spi_num);
155
156	return 0;
157error:
158	smi_devs_unregister(smi);
159
160	return ret;
161}
162
163/**
164 * smi_i2c_probe - Instantiate multiple I2C devices from inst array
165 * @pdev:	Platform device
166 * @smi:	Internal struct for Serial multi instantiate driver
167 * @inst_array:	Array of instances to probe
168 *
169 * Returns the number of I2C devices instantiate, Zero if none is found or a negative error code.
170 */
171static int smi_i2c_probe(struct platform_device *pdev, struct smi *smi,
172			 const struct smi_instance *inst_array)
173{
174	struct i2c_board_info board_info = {};
175	struct device *dev = &pdev->dev;
176	struct acpi_device *adev = ACPI_COMPANION(dev);
177	char name[32];
178	int i, ret, count;
179
180	ret = i2c_acpi_client_count(adev);
181	if (ret < 0)
182		return ret;
183	if (!ret)
184		return -ENOENT;
185
186	count = ret;
187
188	smi->i2c_devs = devm_kcalloc(dev, count, sizeof(*smi->i2c_devs), GFP_KERNEL);
189	if (!smi->i2c_devs)
190		return -ENOMEM;
191
192	for (i = 0; i < count && inst_array[i].type; i++) {
193		memset(&board_info, 0, sizeof(board_info));
194		strscpy(board_info.type, inst_array[i].type, I2C_NAME_SIZE);
195		snprintf(name, sizeof(name), "%s-%s.%d", dev_name(dev), inst_array[i].type, i);
196		board_info.dev_name = name;
197
198		ret = smi_get_irq(pdev, adev, &inst_array[i]);
199		if (ret < 0)
200			goto error;
201		board_info.irq = ret;
202
203		smi->i2c_devs[i] = i2c_acpi_new_device(dev, i, &board_info);
204		if (IS_ERR(smi->i2c_devs[i])) {
205			ret = dev_err_probe(dev, PTR_ERR(smi->i2c_devs[i]),
206					    "Error creating i2c-client, idx %d\n", i);
207			goto error;
208		}
209		smi->i2c_num++;
210	}
211	if (smi->i2c_num < count) {
212		dev_dbg(dev, "Error finding driver, idx %d\n", i);
213		ret = -ENODEV;
214		goto error;
215	}
216
217	dev_info(dev, "Instantiated %d I2C devices.\n", smi->i2c_num);
218
219	return 0;
220error:
221	smi_devs_unregister(smi);
222
223	return ret;
224}
225
226static int smi_probe(struct platform_device *pdev)
227{
228	struct device *dev = &pdev->dev;
229	const struct smi_node *node;
230	struct smi *smi;
231	int ret;
232
233	node = device_get_match_data(dev);
234	if (!node) {
235		dev_dbg(dev, "Error ACPI match data is missing\n");
236		return -ENODEV;
237	}
238
239	smi = devm_kzalloc(dev, sizeof(*smi), GFP_KERNEL);
240	if (!smi)
241		return -ENOMEM;
242
243	platform_set_drvdata(pdev, smi);
244
245	switch (node->bus_type) {
246	case SMI_I2C:
247		return smi_i2c_probe(pdev, smi, node->instances);
248	case SMI_SPI:
249		return smi_spi_probe(pdev, smi, node->instances);
250	case SMI_AUTO_DETECT:
251		/*
252		 * For backwards-compatibility with the existing nodes I2C
253		 * is checked first and if such entries are found ONLY I2C
254		 * devices are created. Since some existing nodes that were
255		 * already handled by this driver could also contain unrelated
256		 * SpiSerialBus nodes that were previously ignored, and this
257		 * preserves that behavior.
258		 */
259		ret = smi_i2c_probe(pdev, smi, node->instances);
260		if (ret != -ENOENT)
261			return ret;
262		return smi_spi_probe(pdev, smi, node->instances);
263	default:
264		return -EINVAL;
265	}
266}
267
268static int smi_remove(struct platform_device *pdev)
269{
270	struct smi *smi = platform_get_drvdata(pdev);
271
272	smi_devs_unregister(smi);
273
274	return 0;
275}
276
277static const struct smi_node bsg1160_data = {
278	.instances = {
279		{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
280		{ "bmc150_magn" },
281		{ "bmg160" },
282		{}
283	},
284	.bus_type = SMI_I2C,
285};
286
287static const struct smi_node bsg2150_data = {
288	.instances = {
289		{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
290		{ "bmc150_magn" },
291		/* The resources describe a 3th client, but it is not really there. */
292		{ "bsg2150_dummy_dev" },
293		{}
294	},
295	.bus_type = SMI_I2C,
296};
297
298static const struct smi_node int3515_data = {
299	.instances = {
300		{ "tps6598x", IRQ_RESOURCE_APIC, 0 },
301		{ "tps6598x", IRQ_RESOURCE_APIC, 1 },
302		{ "tps6598x", IRQ_RESOURCE_APIC, 2 },
303		{ "tps6598x", IRQ_RESOURCE_APIC, 3 },
304		{}
305	},
306	.bus_type = SMI_I2C,
307};
308
309static const struct smi_node cs35l41_hda = {
310	.instances = {
311		{ "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
312		{ "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
313		{ "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
314		{ "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
315		{}
316	},
317	.bus_type = SMI_AUTO_DETECT,
318};
319
320/*
321 * Note new device-ids must also be added to ignore_serial_bus_ids in
322 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
323 */
324static const struct acpi_device_id smi_acpi_ids[] = {
325	{ "BSG1160", (unsigned long)&bsg1160_data },
326	{ "BSG2150", (unsigned long)&bsg2150_data },
327	{ "CSC3551", (unsigned long)&cs35l41_hda },
328	{ "INT3515", (unsigned long)&int3515_data },
329	/* Non-conforming _HID for Cirrus Logic already released */
330	{ "CLSA0100", (unsigned long)&cs35l41_hda },
331	{ "CLSA0101", (unsigned long)&cs35l41_hda },
332	{ }
333};
334MODULE_DEVICE_TABLE(acpi, smi_acpi_ids);
335
336static struct platform_driver smi_driver = {
337	.driver	= {
338		.name = "Serial bus multi instantiate pseudo device driver",
339		.acpi_match_table = smi_acpi_ids,
340	},
341	.probe = smi_probe,
342	.remove = smi_remove,
343};
344module_platform_driver(smi_driver);
345
346MODULE_DESCRIPTION("Serial multi instantiate pseudo device driver");
347MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
348MODULE_LICENSE("GPL");