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 *type_name; 79 int ret; 80 81 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); 82 if (!rfkill) 83 return -ENOMEM; 84 85 device_property_read_string(&pdev->dev, "name", &rfkill->name); 86 device_property_read_string(&pdev->dev, "type", &type_name); 87 88 if (!rfkill->name) 89 rfkill->name = dev_name(&pdev->dev); 90 91 rfkill->type = rfkill_find_type(type_name); 92 93 if (ACPI_HANDLE(&pdev->dev)) { 94 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill); 95 if (ret) 96 return ret; 97 } 98 99 rfkill->clk = devm_clk_get(&pdev->dev, NULL); 100 101 gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW); 102 if (IS_ERR(gpio)) 103 return PTR_ERR(gpio); 104 105 rfkill->reset_gpio = gpio; 106 107 gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW); 108 if (IS_ERR(gpio)) 109 return PTR_ERR(gpio); 110 111 rfkill->shutdown_gpio = gpio; 112 113 /* Make sure at-least one GPIO is defined for this instance */ 114 if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) { 115 dev_err(&pdev->dev, "invalid platform data\n"); 116 return -EINVAL; 117 } 118 119 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, 120 rfkill->type, &rfkill_gpio_ops, 121 rfkill); 122 if (!rfkill->rfkill_dev) 123 return -ENOMEM; 124 125 ret = rfkill_register(rfkill->rfkill_dev); 126 if (ret < 0) 127 goto err_destroy; 128 129 platform_set_drvdata(pdev, rfkill); 130 131 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); 132 133 return 0; 134 135 err_destroy: 136 rfkill_destroy(rfkill->rfkill_dev); 137 138 return ret; 139 } 140 141 static int rfkill_gpio_remove(struct platform_device *pdev) 142 { 143 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); 144 145 rfkill_unregister(rfkill->rfkill_dev); 146 rfkill_destroy(rfkill->rfkill_dev); 147 148 return 0; 149 } 150 151 #ifdef CONFIG_ACPI 152 static const struct acpi_device_id rfkill_acpi_match[] = { 153 { "BCM4752", RFKILL_TYPE_GPS }, 154 { "LNV4752", RFKILL_TYPE_GPS }, 155 { }, 156 }; 157 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match); 158 #endif 159 160 static struct platform_driver rfkill_gpio_driver = { 161 .probe = rfkill_gpio_probe, 162 .remove = rfkill_gpio_remove, 163 .driver = { 164 .name = "rfkill_gpio", 165 .acpi_match_table = ACPI_PTR(rfkill_acpi_match), 166 }, 167 }; 168 169 module_platform_driver(rfkill_gpio_driver); 170 171 MODULE_DESCRIPTION("gpio rfkill"); 172 MODULE_AUTHOR("NVIDIA"); 173 MODULE_LICENSE("GPL"); 174