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 int ret = clk_enable(rfkill->clk); 36 37 if (ret) 38 return ret; 39 } 40 41 gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked); 42 gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked); 43 44 if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled) 45 clk_disable(rfkill->clk); 46 47 rfkill->clk_enabled = !blocked; 48 49 return 0; 50 } 51 52 static const struct rfkill_ops rfkill_gpio_ops = { 53 .set_block = rfkill_gpio_set_power, 54 }; 55 56 static const struct acpi_gpio_params reset_gpios = { 0, 0, false }; 57 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false }; 58 59 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = { 60 { "reset-gpios", &reset_gpios, 1 }, 61 { "shutdown-gpios", &shutdown_gpios, 1 }, 62 { }, 63 }; 64 65 static int rfkill_gpio_acpi_probe(struct device *dev, 66 struct rfkill_gpio_data *rfkill) 67 { 68 const struct acpi_device_id *id; 69 70 id = acpi_match_device(dev->driver->acpi_match_table, dev); 71 if (!id) 72 return -ENODEV; 73 74 rfkill->type = (unsigned)id->driver_data; 75 76 return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios); 77 } 78 79 static int rfkill_gpio_probe(struct platform_device *pdev) 80 { 81 struct rfkill_gpio_data *rfkill; 82 struct gpio_desc *gpio; 83 const char *name_property; 84 const char *type_property; 85 const char *type_name; 86 int ret; 87 88 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); 89 if (!rfkill) 90 return -ENOMEM; 91 92 if (dev_of_node(&pdev->dev)) { 93 name_property = "label"; 94 type_property = "radio-type"; 95 } else { 96 name_property = "name"; 97 type_property = "type"; 98 } 99 device_property_read_string(&pdev->dev, name_property, &rfkill->name); 100 device_property_read_string(&pdev->dev, type_property, &type_name); 101 102 if (!rfkill->name) 103 rfkill->name = dev_name(&pdev->dev); 104 105 rfkill->type = rfkill_find_type(type_name); 106 107 if (ACPI_HANDLE(&pdev->dev)) { 108 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill); 109 if (ret) 110 return ret; 111 } 112 113 rfkill->clk = devm_clk_get(&pdev->dev, NULL); 114 115 gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS); 116 if (IS_ERR(gpio)) 117 return PTR_ERR(gpio); 118 119 rfkill->reset_gpio = gpio; 120 121 gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS); 122 if (IS_ERR(gpio)) 123 return PTR_ERR(gpio); 124 125 rfkill->shutdown_gpio = gpio; 126 127 /* Make sure at-least one GPIO is defined for this instance */ 128 if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) { 129 dev_err(&pdev->dev, "invalid platform data\n"); 130 return -EINVAL; 131 } 132 133 ret = gpiod_direction_output(rfkill->reset_gpio, true); 134 if (ret) 135 return ret; 136 137 ret = gpiod_direction_output(rfkill->shutdown_gpio, true); 138 if (ret) 139 return ret; 140 141 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, 142 rfkill->type, &rfkill_gpio_ops, 143 rfkill); 144 if (!rfkill->rfkill_dev) 145 return -ENOMEM; 146 147 ret = rfkill_register(rfkill->rfkill_dev); 148 if (ret < 0) 149 goto err_destroy; 150 151 platform_set_drvdata(pdev, rfkill); 152 153 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); 154 155 return 0; 156 157 err_destroy: 158 rfkill_destroy(rfkill->rfkill_dev); 159 160 return ret; 161 } 162 163 static int rfkill_gpio_remove(struct platform_device *pdev) 164 { 165 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); 166 167 rfkill_unregister(rfkill->rfkill_dev); 168 rfkill_destroy(rfkill->rfkill_dev); 169 170 return 0; 171 } 172 173 #ifdef CONFIG_ACPI 174 static const struct acpi_device_id rfkill_acpi_match[] = { 175 { "BCM4752", RFKILL_TYPE_GPS }, 176 { "LNV4752", RFKILL_TYPE_GPS }, 177 { }, 178 }; 179 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match); 180 #endif 181 182 static const struct of_device_id rfkill_of_match[] __maybe_unused = { 183 { .compatible = "rfkill-gpio", }, 184 { }, 185 }; 186 MODULE_DEVICE_TABLE(of, rfkill_of_match); 187 188 static struct platform_driver rfkill_gpio_driver = { 189 .probe = rfkill_gpio_probe, 190 .remove = rfkill_gpio_remove, 191 .driver = { 192 .name = "rfkill_gpio", 193 .acpi_match_table = ACPI_PTR(rfkill_acpi_match), 194 .of_match_table = of_match_ptr(rfkill_of_match), 195 }, 196 }; 197 198 module_platform_driver(rfkill_gpio_driver); 199 200 MODULE_DESCRIPTION("gpio rfkill"); 201 MODULE_AUTHOR("NVIDIA"); 202 MODULE_LICENSE("GPL"); 203