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
25 enum smi_bus_type {
26 SMI_I2C,
27 SMI_SPI,
28 SMI_AUTO_DETECT,
29 };
30
31 struct smi_instance {
32 const char *type;
33 unsigned int flags;
34 int irq_idx;
35 };
36
37 struct smi_node {
38 enum smi_bus_type bus_type;
39 struct smi_instance instances[];
40 };
41
42 struct smi {
43 int i2c_num;
44 int spi_num;
45 struct i2c_client **i2c_devs;
46 struct spi_device **spi_devs;
47 };
48
smi_get_irq(struct platform_device * pdev,struct acpi_device * adev,const struct smi_instance * inst)49 static 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
smi_devs_unregister(struct smi * smi)71 static 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 */
smi_spi_probe(struct platform_device * pdev,struct smi * smi,const struct smi_instance * inst_array)88 static 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;
157 error:
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 */
smi_i2c_probe(struct platform_device * pdev,struct smi * smi,const struct smi_instance * inst_array)171 static 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;
220 error:
221 smi_devs_unregister(smi);
222
223 return ret;
224 }
225
smi_probe(struct platform_device * pdev)226 static 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
smi_remove(struct platform_device * pdev)268 static 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
277 static 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
287 static 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
298 static 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
309 static 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 */
324 static 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 };
334 MODULE_DEVICE_TABLE(acpi, smi_acpi_ids);
335
336 static 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 };
344 module_platform_driver(smi_driver);
345
346 MODULE_DESCRIPTION("Serial multi instantiate pseudo device driver");
347 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
348 MODULE_LICENSE("GPL");
349
