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 *safeboot; 70 struct gpio_desc *reset; 71 struct ubx_data *data; 72 int ret; 73 74 gserial = gnss_serial_allocate(serdev, sizeof(*data)); 75 if (IS_ERR(gserial)) { 76 ret = PTR_ERR(gserial); 77 return ret; 78 } 79 80 gserial->ops = &ubx_gserial_ops; 81 82 gserial->gdev->type = GNSS_TYPE_UBX; 83 84 data = gnss_serial_get_drvdata(gserial); 85 86 data->vcc = devm_regulator_get(&serdev->dev, "vcc"); 87 if (IS_ERR(data->vcc)) { 88 ret = PTR_ERR(data->vcc); 89 goto err_free_gserial; 90 } 91 92 ret = devm_regulator_get_enable_optional(&serdev->dev, "v-bckp"); 93 if (ret < 0 && ret != -ENODEV) 94 goto err_free_gserial; 95 96 /* Deassert safeboot */ 97 safeboot = devm_gpiod_get_optional(&serdev->dev, "safeboot", GPIOD_OUT_LOW); 98 if (IS_ERR(safeboot)) { 99 ret = PTR_ERR(safeboot); 100 goto err_free_gserial; 101 } 102 103 /* Deassert reset */ 104 reset = devm_gpiod_get_optional(&serdev->dev, "reset", GPIOD_OUT_LOW); 105 if (IS_ERR(reset)) { 106 ret = PTR_ERR(reset); 107 goto err_free_gserial; 108 } 109 110 ret = gnss_serial_register(gserial); 111 if (ret) 112 goto err_free_gserial; 113 114 return 0; 115 116 err_free_gserial: 117 gnss_serial_free(gserial); 118 119 return ret; 120 } 121 122 static void ubx_remove(struct serdev_device *serdev) 123 { 124 struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); 125 126 gnss_serial_deregister(gserial); 127 gnss_serial_free(gserial); 128 } 129 130 #ifdef CONFIG_OF 131 static const struct of_device_id ubx_of_match[] = { 132 { .compatible = "u-blox,neo-6m" }, 133 { .compatible = "u-blox,neo-8" }, 134 { .compatible = "u-blox,neo-m8" }, 135 {}, 136 }; 137 MODULE_DEVICE_TABLE(of, ubx_of_match); 138 #endif 139 140 static struct serdev_device_driver ubx_driver = { 141 .driver = { 142 .name = "gnss-ubx", 143 .of_match_table = of_match_ptr(ubx_of_match), 144 .pm = &gnss_serial_pm_ops, 145 }, 146 .probe = ubx_probe, 147 .remove = ubx_remove, 148 }; 149 module_serdev_device_driver(ubx_driver); 150 151 MODULE_AUTHOR("Johan Hovold <johan@kernel.org>"); 152 MODULE_DESCRIPTION("u-blox GNSS receiver driver"); 153 MODULE_LICENSE("GPL v2"); 154