platform/x86/serial-multi-instantiate.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Serial multi-instantiate driver, pseudo driver to instantiate multiple
0004  * client devices from a single fwnode.
0005  *
0006  * Copyright 2018 Hans de Goede <hdegoede@redhat.com>
0007  */
0008
0009 #include <linux/acpi.h>
0010 #include <linux/bits.h>
0011 #include <linux/i2c.h>
0012 #include <linux/interrupt.h>
0013 #include <linux/kernel.h>
0014 #include <linux/module.h>
0015 #include <linux/platform_device.h>
0016 #include <linux/property.h>
0017 #include <linux/spi/spi.h>
0018 #include <linux/types.h>
0019
0020 #define IRQ_RESOURCE_TYPE   GENMASK(1, 0)
0021 #define IRQ_RESOURCE_NONE   0
0022 #define IRQ_RESOURCE_GPIO   1
0023 #define IRQ_RESOURCE_APIC   2
0024
0025 enum smi_bus_type {
0026     SMI_I2C,
0027     SMI_SPI,
0028     SMI_AUTO_DETECT,
0029 };
0030
0031 struct smi_instance {
0032     const char *type;
0033     unsigned int flags;
0034     int irq_idx;
0035 };
0036
0037 struct smi_node {
0038     enum smi_bus_type bus_type;
0039     struct smi_instance instances[];
0040 };
0041
0042 struct smi {
0043     int i2c_num;
0044     int spi_num;
0045     struct i2c_client **i2c_devs;
0046     struct spi_device **spi_devs;
0047 };
0048
0049 static int smi_get_irq(struct platform_device *pdev, struct acpi_device *adev,
0050                const struct smi_instance *inst)
0051 {
0052     int ret;
0053
0054     switch (inst->flags & IRQ_RESOURCE_TYPE) {
0055     case IRQ_RESOURCE_GPIO:
0056         ret = acpi_dev_gpio_irq_get(adev, inst->irq_idx);
0057         break;
0058     case IRQ_RESOURCE_APIC:
0059         ret = platform_get_irq(pdev, inst->irq_idx);
0060         break;
0061     default:
0062         return 0;
0063     }
0064     if (ret < 0)
0065         return dev_err_probe(&pdev->dev, ret, "Error requesting irq at index %d\n",
0066                      inst->irq_idx);
0067
0068     return ret;
0069 }
0070
0071 static void smi_devs_unregister(struct smi *smi)
0072 {
0073     while (smi->i2c_num--)
0074         i2c_unregister_device(smi->i2c_devs[smi->i2c_num]);
0075
0076     while (smi->spi_num--)
0077         spi_unregister_device(smi->spi_devs[smi->spi_num]);
0078 }
0079
0080 /**
0081  * smi_spi_probe - Instantiate multiple SPI devices from inst array
0082  * @pdev:   Platform device
0083  * @smi:    Internal struct for Serial multi instantiate driver
0084  * @inst_array: Array of instances to probe
0085  *
0086  * Returns the number of SPI devices instantiate, Zero if none is found or a negative error code.
0087  */
0088 static int smi_spi_probe(struct platform_device *pdev, struct smi *smi,
0089              const struct smi_instance *inst_array)
0090 {
0091     struct device *dev = &pdev->dev;
0092     struct acpi_device *adev = ACPI_COMPANION(dev);
0093     struct spi_controller *ctlr;
0094     struct spi_device *spi_dev;
0095     char name[50];
0096     int i, ret, count;
0097
0098     ret = acpi_spi_count_resources(adev);
0099     if (ret < 0)
0100         return ret;
0101     if (!ret)
0102         return -ENOENT;
0103
0104     count = ret;
0105
0106     smi->spi_devs = devm_kcalloc(dev, count, sizeof(*smi->spi_devs), GFP_KERNEL);
0107     if (!smi->spi_devs)
0108         return -ENOMEM;
0109
0110     for (i = 0; i < count && inst_array[i].type; i++) {
0111
0112         spi_dev = acpi_spi_device_alloc(NULL, adev, i);
0113         if (IS_ERR(spi_dev)) {
0114             ret = dev_err_probe(dev, PTR_ERR(spi_dev), "failed to allocate SPI device %s from ACPI\n",
0115                         dev_name(&adev->dev));
0116             goto error;
0117         }
0118
0119         ctlr = spi_dev->controller;
0120
0121         strscpy(spi_dev->modalias, inst_array[i].type, sizeof(spi_dev->modalias));
0122
0123         ret = smi_get_irq(pdev, adev, &inst_array[i]);
0124         if (ret < 0) {
0125             spi_dev_put(spi_dev);
0126             goto error;
0127         }
0128         spi_dev->irq = ret;
0129
0130         snprintf(name, sizeof(name), "%s-%s-%s.%d", dev_name(&ctlr->dev), dev_name(dev),
0131              inst_array[i].type, i);
0132         spi_dev->dev.init_name = name;
0133
0134         ret = spi_add_device(spi_dev);
0135         if (ret) {
0136             dev_err_probe(&ctlr->dev, ret, "failed to add SPI device %s from ACPI\n",
0137                       dev_name(&adev->dev));
0138             spi_dev_put(spi_dev);
0139             goto error;
0140         }
0141
0142         dev_dbg(dev, "SPI device %s using chip select %u", name, spi_dev->chip_select);
0143
0144         smi->spi_devs[i] = spi_dev;
0145         smi->spi_num++;
0146     }
0147
0148     if (smi->spi_num < count) {
0149         dev_dbg(dev, "Error finding driver, idx %d\n", i);
0150         ret = -ENODEV;
0151         goto error;
0152     }
0153
0154     dev_info(dev, "Instantiated %d SPI devices.\n", smi->spi_num);
0155
0156     return 0;
0157 error:
0158     smi_devs_unregister(smi);
0159
0160     return ret;
0161 }
0162
0163 /**
0164  * smi_i2c_probe - Instantiate multiple I2C devices from inst array
0165  * @pdev:   Platform device
0166  * @smi:    Internal struct for Serial multi instantiate driver
0167  * @inst_array: Array of instances to probe
0168  *
0169  * Returns the number of I2C devices instantiate, Zero if none is found or a negative error code.
0170  */
0171 static int smi_i2c_probe(struct platform_device *pdev, struct smi *smi,
0172              const struct smi_instance *inst_array)
0173 {
0174     struct i2c_board_info board_info = {};
0175     struct device *dev = &pdev->dev;
0176     struct acpi_device *adev = ACPI_COMPANION(dev);
0177     char name[32];
0178     int i, ret, count;
0179
0180     ret = i2c_acpi_client_count(adev);
0181     if (ret < 0)
0182         return ret;
0183     if (!ret)
0184         return -ENOENT;
0185
0186     count = ret;
0187
0188     smi->i2c_devs = devm_kcalloc(dev, count, sizeof(*smi->i2c_devs), GFP_KERNEL);
0189     if (!smi->i2c_devs)
0190         return -ENOMEM;
0191
0192     for (i = 0; i < count && inst_array[i].type; i++) {
0193         memset(&board_info, 0, sizeof(board_info));
0194         strscpy(board_info.type, inst_array[i].type, I2C_NAME_SIZE);
0195         snprintf(name, sizeof(name), "%s-%s.%d", dev_name(dev), inst_array[i].type, i);
0196         board_info.dev_name = name;
0197
0198         ret = smi_get_irq(pdev, adev, &inst_array[i]);
0199         if (ret < 0)
0200             goto error;
0201         board_info.irq = ret;
0202
0203         smi->i2c_devs[i] = i2c_acpi_new_device(dev, i, &board_info);
0204         if (IS_ERR(smi->i2c_devs[i])) {
0205             ret = dev_err_probe(dev, PTR_ERR(smi->i2c_devs[i]),
0206                         "Error creating i2c-client, idx %d\n", i);
0207             goto error;
0208         }
0209         smi->i2c_num++;
0210     }
0211     if (smi->i2c_num < count) {
0212         dev_dbg(dev, "Error finding driver, idx %d\n", i);
0213         ret = -ENODEV;
0214         goto error;
0215     }
0216
0217     dev_info(dev, "Instantiated %d I2C devices.\n", smi->i2c_num);
0218
0219     return 0;
0220 error:
0221     smi_devs_unregister(smi);
0222
0223     return ret;
0224 }
0225
0226 static int smi_probe(struct platform_device *pdev)
0227 {
0228     struct device *dev = &pdev->dev;
0229     const struct smi_node *node;
0230     struct smi *smi;
0231     int ret;
0232
0233     node = device_get_match_data(dev);
0234     if (!node) {
0235         dev_dbg(dev, "Error ACPI match data is missing\n");
0236         return -ENODEV;
0237     }
0238
0239     smi = devm_kzalloc(dev, sizeof(*smi), GFP_KERNEL);
0240     if (!smi)
0241         return -ENOMEM;
0242
0243     platform_set_drvdata(pdev, smi);
0244
0245     switch (node->bus_type) {
0246     case SMI_I2C:
0247         return smi_i2c_probe(pdev, smi, node->instances);
0248     case SMI_SPI:
0249         return smi_spi_probe(pdev, smi, node->instances);
0250     case SMI_AUTO_DETECT:
0251         /*
0252          * For backwards-compatibility with the existing nodes I2C
0253          * is checked first and if such entries are found ONLY I2C
0254          * devices are created. Since some existing nodes that were
0255          * already handled by this driver could also contain unrelated
0256          * SpiSerialBus nodes that were previously ignored, and this
0257          * preserves that behavior.
0258          */
0259         ret = smi_i2c_probe(pdev, smi, node->instances);
0260         if (ret != -ENOENT)
0261             return ret;
0262         return smi_spi_probe(pdev, smi, node->instances);
0263     default:
0264         return -EINVAL;
0265     }
0266 }
0267
0268 static int smi_remove(struct platform_device *pdev)
0269 {
0270     struct smi *smi = platform_get_drvdata(pdev);
0271
0272     smi_devs_unregister(smi);
0273
0274     return 0;
0275 }
0276
0277 static const struct smi_node bsg1160_data = {
0278     .instances = {
0279         { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
0280         { "bmc150_magn" },
0281         { "bmg160" },
0282         {}
0283     },
0284     .bus_type = SMI_I2C,
0285 };
0286
0287 static const struct smi_node bsg2150_data = {
0288     .instances = {
0289         { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
0290         { "bmc150_magn" },
0291         /* The resources describe a 3th client, but it is not really there. */
0292         { "bsg2150_dummy_dev" },
0293         {}
0294     },
0295     .bus_type = SMI_I2C,
0296 };
0297
0298 static const struct smi_node int3515_data = {
0299     .instances = {
0300         { "tps6598x", IRQ_RESOURCE_APIC, 0 },
0301         { "tps6598x", IRQ_RESOURCE_APIC, 1 },
0302         { "tps6598x", IRQ_RESOURCE_APIC, 2 },
0303         { "tps6598x", IRQ_RESOURCE_APIC, 3 },
0304         {}
0305     },
0306     .bus_type = SMI_I2C,
0307 };
0308
0309 static const struct smi_node cs35l41_hda = {
0310     .instances = {
0311         { "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
0312         { "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
0313         { "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
0314         { "cs35l41-hda", IRQ_RESOURCE_GPIO, 0 },
0315         {}
0316     },
0317     .bus_type = SMI_AUTO_DETECT,
0318 };
0319
0320 /*
0321  * Note new device-ids must also be added to ignore_serial_bus_ids in
0322  * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
0323  */
0324 static const struct acpi_device_id smi_acpi_ids[] = {
0325     { "BSG1160", (unsigned long)&bsg1160_data },
0326     { "BSG2150", (unsigned long)&bsg2150_data },
0327     { "CSC3551", (unsigned long)&cs35l41_hda },
0328     { "INT3515", (unsigned long)&int3515_data },
0329     /* Non-conforming _HID for Cirrus Logic already released */
0330     { "CLSA0100", (unsigned long)&cs35l41_hda },
0331     { "CLSA0101", (unsigned long)&cs35l41_hda },
0332     { }
0333 };
0334 MODULE_DEVICE_TABLE(acpi, smi_acpi_ids);
0335
0336 static struct platform_driver smi_driver = {
0337     .driver = {
0338         .name = "Serial bus multi instantiate pseudo device driver",
0339         .acpi_match_table = smi_acpi_ids,
0340     },
0341     .probe = smi_probe,
0342     .remove = smi_remove,
0343 };
0344 module_platform_driver(smi_driver);
0345
0346 MODULE_DESCRIPTION("Serial multi instantiate pseudo device driver");
0347 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
0348 MODULE_LICENSE("GPL");