1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (c) 2011, NVIDIA Corporation. 4 */ 5 6 #include <linux/init.h> 7 #include <linux/kernel.h> 8 #include <linux/module.h> 9 #include <linux/mod_devicetable.h> 10 #include <linux/rfkill.h> 11 #include <linux/platform_device.h> 12 #include <linux/clk.h> 13 #include <linux/slab.h> 14 #include <linux/acpi.h> 15 #include <linux/gpio/consumer.h> 16 17 struct rfkill_gpio_data { 18 const char *name; 19 enum rfkill_type type; 20 struct gpio_desc *reset_gpio; 21 struct gpio_desc *shutdown_gpio; 22 23 struct rfkill *rfkill_dev; 24 struct clk *clk; 25 26 bool clk_enabled; 27 }; 28 29 static int rfkill_gpio_set_power(void *data, bool blocked) 30 { 31 struct rfkill_gpio_data *rfkill = data; 32 33 if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) 34 clk_enable(rfkill->clk); 35 36 gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked); 37 gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked); 38 39 if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled) 40 clk_disable(rfkill->clk); 41 42 rfkill->clk_enabled = !blocked; 43 44 return 0; 45 } 46 47 static const struct rfkill_ops rfkill_gpio_ops = { 48 .set_block = rfkill_gpio_set_power, 49 }; 50 51 static const struct acpi_gpio_params reset_gpios = { 0, 0, false }; 52 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false }; 53 54 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = { 55 { "reset-gpios", &reset_gpios, 1 }, 56 { "shutdown-gpios", &shutdown_gpios, 1 }, 57 { }, 58 }; 59 60 static int rfkill_gpio_acpi_probe(struct device *dev, 61 struct rfkill_gpio_data *rfkill) 62 { 63 const struct acpi_device_id *id; 64 65 id = acpi_match_device(dev->driver->acpi_match_table, dev); 66 if (!id) 67 return -ENODEV; 68 69 rfkill->type = (unsigned)id->driver_data; 70 71 return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios); 72 } 73 74 static int rfkill_gpio_probe(struct platform_device *pdev) 75 { 76 struct rfkill_gpio_data *rfkill; 77 struct gpio_desc *gpio; 78 const char *name_property; 79 const char *type_property; 80 const char *type_name; 81 int ret; 82 83 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); 84 if (!rfkill) 85 return -ENOMEM; 86 87 if (dev_of_node(&pdev->dev)) { 88 name_property = "label"; 89 type_property = "radio-type"; 90 } else { 91 name_property = "name"; 92 type_property = "type"; 93 } 94 device_property_read_string(&pdev->dev, name_property, &rfkill->name); 95 device_property_read_string(&pdev->dev, type_property, &type_name); 96 97 if (!rfkill->name) 98 rfkill->name = dev_name(&pdev->dev); 99 100 rfkill->type = rfkill_find_type(type_name); 101 102 if (ACPI_HANDLE(&pdev->dev)) { 103 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill); 104 if (ret) 105 return ret; 106 } 107 108 rfkill->clk = devm_clk_get(&pdev->dev, NULL); 109 110 gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW); 111 if (IS_ERR(gpio)) 112 return PTR_ERR(gpio); 113 114 rfkill->reset_gpio = gpio; 115 116 gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW); 117 if (IS_ERR(gpio)) 118 return PTR_ERR(gpio); 119 120 rfkill->shutdown_gpio = gpio; 121 122 /* Make sure at-least one GPIO is defined for this instance */ 123 if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) { 124 dev_err(&pdev->dev, "invalid platform data\n"); 125 return -EINVAL; 126 } 127 128 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, 129 rfkill->type, &rfkill_gpio_ops, 130 rfkill); 131 if (!rfkill->rfkill_dev) 132 return -ENOMEM; 133 134 ret = rfkill_register(rfkill->rfkill_dev); 135 if (ret < 0) 136 goto err_destroy; 137 138 platform_set_drvdata(pdev, rfkill); 139 140 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); 141 142 return 0; 143 144 err_destroy: 145 rfkill_destroy(rfkill->rfkill_dev); 146 147 return ret; 148 } 149 150 static int rfkill_gpio_remove(struct platform_device *pdev) 151 { 152 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); 153 154 rfkill_unregister(rfkill->rfkill_dev); 155 rfkill_destroy(rfkill->rfkill_dev); 156 157 return 0; 158 } 159 160 #ifdef CONFIG_ACPI 161 static const struct acpi_device_id rfkill_acpi_match[] = { 162 { "BCM4752", RFKILL_TYPE_GPS }, 163 { "LNV4752", RFKILL_TYPE_GPS }, 164 { }, 165 }; 166 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match); 167 #endif 168 169 static const struct of_device_id rfkill_of_match[] __maybe_unused = { 170 { .compatible = "rfkill-gpio", }, 171 { }, 172 }; 173 MODULE_DEVICE_TABLE(of, rfkill_of_match); 174 175 static struct platform_driver rfkill_gpio_driver = { 176 .probe = rfkill_gpio_probe, 177 .remove = rfkill_gpio_remove, 178 .driver = { 179 .name = "rfkill_gpio", 180 .acpi_match_table = ACPI_PTR(rfkill_acpi_match), 181 .of_match_table = of_match_ptr(rfkill_of_match), 182 }, 183 }; 184 185 module_platform_driver(rfkill_gpio_driver); 186 187 MODULE_DESCRIPTION("gpio rfkill"); 188 MODULE_AUTHOR("NVIDIA"); 189 MODULE_LICENSE("GPL"); 190