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/of.h> 12 #include <linux/platform_device.h> 13 #include <linux/clk.h> 14 #include <linux/slab.h> 15 #include <linux/acpi.h> 16 #include <linux/gpio/consumer.h> 17 18 struct rfkill_gpio_data { 19 const char *name; 20 enum rfkill_type type; 21 struct gpio_desc *reset_gpio; 22 struct gpio_desc *shutdown_gpio; 23 24 struct rfkill *rfkill_dev; 25 struct clk *clk; 26 27 bool clk_enabled; 28 }; 29 30 static int rfkill_gpio_set_power(void *data, bool blocked) 31 { 32 struct rfkill_gpio_data *rfkill = data; 33 34 if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) 35 clk_enable(rfkill->clk); 36 37 gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked); 38 gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked); 39 40 if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled) 41 clk_disable(rfkill->clk); 42 43 rfkill->clk_enabled = !blocked; 44 45 return 0; 46 } 47 48 static const struct rfkill_ops rfkill_gpio_ops = { 49 .set_block = rfkill_gpio_set_power, 50 }; 51 52 static const struct acpi_gpio_params reset_gpios = { 0, 0, false }; 53 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false }; 54 55 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = { 56 { "reset-gpios", &reset_gpios, 1 }, 57 { "shutdown-gpios", &shutdown_gpios, 1 }, 58 { }, 59 }; 60 61 static int rfkill_gpio_acpi_probe(struct device *dev, 62 struct rfkill_gpio_data *rfkill) 63 { 64 const struct acpi_device_id *id; 65 66 id = acpi_match_device(dev->driver->acpi_match_table, dev); 67 if (!id) 68 return -ENODEV; 69 70 rfkill->type = (unsigned)id->driver_data; 71 72 return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios); 73 } 74 75 static int rfkill_gpio_probe(struct platform_device *pdev) 76 { 77 struct rfkill_gpio_data *rfkill; 78 struct gpio_desc *gpio; 79 const char *name_property; 80 const char *type_property; 81 const char *type_name; 82 int ret; 83 84 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); 85 if (!rfkill) 86 return -ENOMEM; 87 88 if (dev_of_node(&pdev->dev)) { 89 name_property = "label"; 90 type_property = "radio-type"; 91 } else { 92 name_property = "name"; 93 type_property = "type"; 94 } 95 device_property_read_string(&pdev->dev, name_property, &rfkill->name); 96 device_property_read_string(&pdev->dev, type_property, &type_name); 97 98 if (!rfkill->name) 99 rfkill->name = dev_name(&pdev->dev); 100 101 rfkill->type = rfkill_find_type(type_name); 102 103 if (ACPI_HANDLE(&pdev->dev)) { 104 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill); 105 if (ret) 106 return ret; 107 } 108 109 rfkill->clk = devm_clk_get(&pdev->dev, NULL); 110 111 gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS); 112 if (IS_ERR(gpio)) 113 return PTR_ERR(gpio); 114 115 rfkill->reset_gpio = gpio; 116 117 gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS); 118 if (IS_ERR(gpio)) 119 return PTR_ERR(gpio); 120 121 rfkill->shutdown_gpio = gpio; 122 123 /* Make sure at-least one GPIO is defined for this instance */ 124 if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) { 125 dev_err(&pdev->dev, "invalid platform data\n"); 126 return -EINVAL; 127 } 128 129 ret = gpiod_direction_output(rfkill->reset_gpio, true); 130 if (ret) 131 return ret; 132 133 ret = gpiod_direction_output(rfkill->shutdown_gpio, true); 134 if (ret) 135 return ret; 136 137 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, 138 rfkill->type, &rfkill_gpio_ops, 139 rfkill); 140 if (!rfkill->rfkill_dev) 141 return -ENOMEM; 142 143 ret = rfkill_register(rfkill->rfkill_dev); 144 if (ret < 0) 145 goto err_destroy; 146 147 platform_set_drvdata(pdev, rfkill); 148 149 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); 150 151 return 0; 152 153 err_destroy: 154 rfkill_destroy(rfkill->rfkill_dev); 155 156 return ret; 157 } 158 159 static int rfkill_gpio_remove(struct platform_device *pdev) 160 { 161 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); 162 163 rfkill_unregister(rfkill->rfkill_dev); 164 rfkill_destroy(rfkill->rfkill_dev); 165 166 return 0; 167 } 168 169 #ifdef CONFIG_ACPI 170 static const struct acpi_device_id rfkill_acpi_match[] = { 171 { "BCM4752", RFKILL_TYPE_GPS }, 172 { "LNV4752", RFKILL_TYPE_GPS }, 173 { }, 174 }; 175 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match); 176 #endif 177 178 static const struct of_device_id rfkill_of_match[] __maybe_unused = { 179 { .compatible = "rfkill-gpio", }, 180 { }, 181 }; 182 MODULE_DEVICE_TABLE(of, rfkill_of_match); 183 184 static struct platform_driver rfkill_gpio_driver = { 185 .probe = rfkill_gpio_probe, 186 .remove = rfkill_gpio_remove, 187 .driver = { 188 .name = "rfkill_gpio", 189 .acpi_match_table = ACPI_PTR(rfkill_acpi_match), 190 .of_match_table = of_match_ptr(rfkill_of_match), 191 }, 192 }; 193 194 module_platform_driver(rfkill_gpio_driver); 195 196 MODULE_DESCRIPTION("gpio rfkill"); 197 MODULE_AUTHOR("NVIDIA"); 198 MODULE_LICENSE("GPL"); 199