1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Mediatek 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/init.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/regulator/consumer.h> 15 #include <linux/serdev.h> 16 17 #include "serial.h" 18 19 struct mtk_data { 20 struct regulator *vbackup; 21 struct regulator *vcc; 22 }; 23 24 static int mtk_set_active(struct gnss_serial *gserial) 25 { 26 struct mtk_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 mtk_set_standby(struct gnss_serial *gserial) 37 { 38 struct mtk_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 mtk_set_power(struct gnss_serial *gserial, 49 enum gnss_serial_pm_state state) 50 { 51 switch (state) { 52 case GNSS_SERIAL_ACTIVE: 53 return mtk_set_active(gserial); 54 case GNSS_SERIAL_OFF: 55 case GNSS_SERIAL_STANDBY: 56 return mtk_set_standby(gserial); 57 } 58 59 return -EINVAL; 60 } 61 62 static const struct gnss_serial_ops mtk_gserial_ops = { 63 .set_power = mtk_set_power, 64 }; 65 66 static int mtk_probe(struct serdev_device *serdev) 67 { 68 struct gnss_serial *gserial; 69 struct mtk_data *data; 70 int ret; 71 72 gserial = gnss_serial_allocate(serdev, sizeof(*data)); 73 if (IS_ERR(gserial)) { 74 ret = PTR_ERR(gserial); 75 return ret; 76 } 77 78 gserial->ops = &mtk_gserial_ops; 79 80 gserial->gdev->type = GNSS_TYPE_MTK; 81 82 data = gnss_serial_get_drvdata(gserial); 83 84 data->vcc = devm_regulator_get(&serdev->dev, "vcc"); 85 if (IS_ERR(data->vcc)) { 86 ret = PTR_ERR(data->vcc); 87 goto err_free_gserial; 88 } 89 90 data->vbackup = devm_regulator_get_optional(&serdev->dev, "vbackup"); 91 if (IS_ERR(data->vbackup)) { 92 ret = PTR_ERR(data->vbackup); 93 if (ret == -ENODEV) 94 data->vbackup = NULL; 95 else 96 goto err_free_gserial; 97 } 98 99 if (data->vbackup) { 100 ret = regulator_enable(data->vbackup); 101 if (ret) 102 goto err_free_gserial; 103 } 104 105 ret = gnss_serial_register(gserial); 106 if (ret) 107 goto err_disable_vbackup; 108 109 return 0; 110 111 err_disable_vbackup: 112 if (data->vbackup) 113 regulator_disable(data->vbackup); 114 err_free_gserial: 115 gnss_serial_free(gserial); 116 117 return ret; 118 } 119 120 static void mtk_remove(struct serdev_device *serdev) 121 { 122 struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); 123 struct mtk_data *data = gnss_serial_get_drvdata(gserial); 124 125 gnss_serial_deregister(gserial); 126 if (data->vbackup) 127 regulator_disable(data->vbackup); 128 gnss_serial_free(gserial); 129 } 130 131 #ifdef CONFIG_OF 132 static const struct of_device_id mtk_of_match[] = { 133 { .compatible = "globaltop,pa6h" }, 134 {}, 135 }; 136 MODULE_DEVICE_TABLE(of, mtk_of_match); 137 #endif 138 139 static struct serdev_device_driver mtk_driver = { 140 .driver = { 141 .name = "gnss-mtk", 142 .of_match_table = of_match_ptr(mtk_of_match), 143 .pm = &gnss_serial_pm_ops, 144 }, 145 .probe = mtk_probe, 146 .remove = mtk_remove, 147 }; 148 module_serdev_device_driver(mtk_driver); 149 150 MODULE_AUTHOR("Loys Ollivier <lollivier@baylibre.com>"); 151 MODULE_DESCRIPTION("Mediatek GNSS receiver driver"); 152 MODULE_LICENSE("GPL v2"); 153