1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * u-blox GNSS receiver driver 4 * 5 * Copyright (C) 2018 Johan Hovold <johan@kernel.org> 6 */ 7 8 #include <linux/errno.h> 9 #include <linux/gnss.h> 10 #include <linux/gpio/consumer.h> 11 #include <linux/init.h> 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/of.h> 15 #include <linux/regulator/consumer.h> 16 #include <linux/serdev.h> 17 18 #include "serial.h" 19 20 struct ubx_data { 21 struct regulator *vcc; 22 }; 23 24 static int ubx_set_active(struct gnss_serial *gserial) 25 { 26 struct ubx_data *data = gnss_serial_get_drvdata(gserial); 27 int ret; 28 29 ret = regulator_enable(data->vcc); 30 if (ret) 31 return ret; 32 33 return 0; 34 } 35 36 static int ubx_set_standby(struct gnss_serial *gserial) 37 { 38 struct ubx_data *data = gnss_serial_get_drvdata(gserial); 39 int ret; 40 41 ret = regulator_disable(data->vcc); 42 if (ret) 43 return ret; 44 45 return 0; 46 } 47 48 static int ubx_set_power(struct gnss_serial *gserial, 49 enum gnss_serial_pm_state state) 50 { 51 switch (state) { 52 case GNSS_SERIAL_ACTIVE: 53 return ubx_set_active(gserial); 54 case GNSS_SERIAL_OFF: 55 case GNSS_SERIAL_STANDBY: 56 return ubx_set_standby(gserial); 57 } 58 59 return -EINVAL; 60 } 61 62 static const struct gnss_serial_ops ubx_gserial_ops = { 63 .set_power = ubx_set_power, 64 }; 65 66 static int ubx_probe(struct serdev_device *serdev) 67 { 68 struct gnss_serial *gserial; 69 struct gpio_desc *reset; 70 struct ubx_data *data; 71 int ret; 72 73 gserial = gnss_serial_allocate(serdev, sizeof(*data)); 74 if (IS_ERR(gserial)) { 75 ret = PTR_ERR(gserial); 76 return ret; 77 } 78 79 gserial->ops = &ubx_gserial_ops; 80 81 gserial->gdev->type = GNSS_TYPE_UBX; 82 83 data = gnss_serial_get_drvdata(gserial); 84 85 data->vcc = devm_regulator_get(&serdev->dev, "vcc"); 86 if (IS_ERR(data->vcc)) { 87 ret = PTR_ERR(data->vcc); 88 goto err_free_gserial; 89 } 90 91 ret = devm_regulator_get_enable_optional(&serdev->dev, "v-bckp"); 92 if (ret < 0 && ret != -ENODEV) 93 goto err_free_gserial; 94 95 /* Deassert reset */ 96 reset = devm_gpiod_get_optional(&serdev->dev, "reset", GPIOD_OUT_LOW); 97 if (IS_ERR(reset)) { 98 ret = PTR_ERR(reset); 99 goto err_free_gserial; 100 } 101 102 ret = gnss_serial_register(gserial); 103 if (ret) 104 goto err_free_gserial; 105 106 return 0; 107 108 err_free_gserial: 109 gnss_serial_free(gserial); 110 111 return ret; 112 } 113 114 static void ubx_remove(struct serdev_device *serdev) 115 { 116 struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); 117 118 gnss_serial_deregister(gserial); 119 gnss_serial_free(gserial); 120 } 121 122 #ifdef CONFIG_OF 123 static const struct of_device_id ubx_of_match[] = { 124 { .compatible = "u-blox,neo-6m" }, 125 { .compatible = "u-blox,neo-8" }, 126 { .compatible = "u-blox,neo-m8" }, 127 {}, 128 }; 129 MODULE_DEVICE_TABLE(of, ubx_of_match); 130 #endif 131 132 static struct serdev_device_driver ubx_driver = { 133 .driver = { 134 .name = "gnss-ubx", 135 .of_match_table = of_match_ptr(ubx_of_match), 136 .pm = &gnss_serial_pm_ops, 137 }, 138 .probe = ubx_probe, 139 .remove = ubx_remove, 140 }; 141 module_serdev_device_driver(ubx_driver); 142 143 MODULE_AUTHOR("Johan Hovold <johan@kernel.org>"); 144 MODULE_DESCRIPTION("u-blox GNSS receiver driver"); 145 MODULE_LICENSE("GPL v2"); 146