1 /* 2 * Copyright (c) 2011, NVIDIA Corporation. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 12 * more details. 13 * 14 * You should have received a copy of the GNU General Public License along 15 * with this program; if not, write to the Free Software Foundation, Inc., 16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 17 */ 18 19 #include <linux/gpio.h> 20 #include <linux/init.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/rfkill.h> 24 #include <linux/platform_device.h> 25 #include <linux/clk.h> 26 #include <linux/slab.h> 27 #include <linux/acpi.h> 28 #include <linux/gpio/consumer.h> 29 30 struct rfkill_gpio_data { 31 const char *name; 32 enum rfkill_type type; 33 struct gpio_desc *reset_gpio; 34 struct gpio_desc *shutdown_gpio; 35 36 struct rfkill *rfkill_dev; 37 struct clk *clk; 38 39 bool clk_enabled; 40 }; 41 42 static int rfkill_gpio_set_power(void *data, bool blocked) 43 { 44 struct rfkill_gpio_data *rfkill = data; 45 46 if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) 47 clk_enable(rfkill->clk); 48 49 gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked); 50 gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked); 51 52 if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled) 53 clk_disable(rfkill->clk); 54 55 rfkill->clk_enabled = !blocked; 56 57 return 0; 58 } 59 60 static const struct rfkill_ops rfkill_gpio_ops = { 61 .set_block = rfkill_gpio_set_power, 62 }; 63 64 static const struct acpi_gpio_params reset_gpios = { 0, 0, false }; 65 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false }; 66 67 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = { 68 { "reset-gpios", &reset_gpios, 1 }, 69 { "shutdown-gpios", &shutdown_gpios, 1 }, 70 { }, 71 }; 72 73 static int rfkill_gpio_acpi_probe(struct device *dev, 74 struct rfkill_gpio_data *rfkill) 75 { 76 const struct acpi_device_id *id; 77 78 id = acpi_match_device(dev->driver->acpi_match_table, dev); 79 if (!id) 80 return -ENODEV; 81 82 rfkill->type = (unsigned)id->driver_data; 83 84 return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios); 85 } 86 87 static int rfkill_gpio_probe(struct platform_device *pdev) 88 { 89 struct rfkill_gpio_data *rfkill; 90 struct gpio_desc *gpio; 91 const char *type_name; 92 int ret; 93 94 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); 95 if (!rfkill) 96 return -ENOMEM; 97 98 device_property_read_string(&pdev->dev, "name", &rfkill->name); 99 device_property_read_string(&pdev->dev, "type", &type_name); 100 101 if (!rfkill->name) 102 rfkill->name = dev_name(&pdev->dev); 103 104 rfkill->type = rfkill_find_type(type_name); 105 106 if (ACPI_HANDLE(&pdev->dev)) { 107 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill); 108 if (ret) 109 return ret; 110 } 111 112 rfkill->clk = devm_clk_get(&pdev->dev, NULL); 113 114 gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW); 115 if (IS_ERR(gpio)) 116 return PTR_ERR(gpio); 117 118 rfkill->reset_gpio = gpio; 119 120 gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW); 121 if (IS_ERR(gpio)) 122 return PTR_ERR(gpio); 123 124 rfkill->shutdown_gpio = gpio; 125 126 /* Make sure at-least one GPIO is defined for this instance */ 127 if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) { 128 dev_err(&pdev->dev, "invalid platform data\n"); 129 return -EINVAL; 130 } 131 132 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, 133 rfkill->type, &rfkill_gpio_ops, 134 rfkill); 135 if (!rfkill->rfkill_dev) 136 return -ENOMEM; 137 138 ret = rfkill_register(rfkill->rfkill_dev); 139 if (ret < 0) 140 goto err_destroy; 141 142 platform_set_drvdata(pdev, rfkill); 143 144 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); 145 146 return 0; 147 148 err_destroy: 149 rfkill_destroy(rfkill->rfkill_dev); 150 151 return ret; 152 } 153 154 static int rfkill_gpio_remove(struct platform_device *pdev) 155 { 156 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); 157 158 rfkill_unregister(rfkill->rfkill_dev); 159 rfkill_destroy(rfkill->rfkill_dev); 160 161 return 0; 162 } 163 164 #ifdef CONFIG_ACPI 165 static const struct acpi_device_id rfkill_acpi_match[] = { 166 { "BCM4752", RFKILL_TYPE_GPS }, 167 { "LNV4752", RFKILL_TYPE_GPS }, 168 { }, 169 }; 170 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match); 171 #endif 172 173 static struct platform_driver rfkill_gpio_driver = { 174 .probe = rfkill_gpio_probe, 175 .remove = rfkill_gpio_remove, 176 .driver = { 177 .name = "rfkill_gpio", 178 .acpi_match_table = ACPI_PTR(rfkill_acpi_match), 179 }, 180 }; 181 182 module_platform_driver(rfkill_gpio_driver); 183 184 MODULE_DESCRIPTION("gpio rfkill"); 185 MODULE_AUTHOR("NVIDIA"); 186 MODULE_LICENSE("GPL"); 187