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 acpi_dev_add_driver_gpios(ACPI_COMPANION(dev), 85 acpi_rfkill_default_gpios); 86 } 87 88 static int rfkill_gpio_probe(struct platform_device *pdev) 89 { 90 struct rfkill_gpio_data *rfkill; 91 struct gpio_desc *gpio; 92 const char *type_name; 93 int ret; 94 95 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); 96 if (!rfkill) 97 return -ENOMEM; 98 99 device_property_read_string(&pdev->dev, "name", &rfkill->name); 100 device_property_read_string(&pdev->dev, "type", &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_OUT_LOW); 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_OUT_LOW); 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 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, 134 rfkill->type, &rfkill_gpio_ops, 135 rfkill); 136 if (!rfkill->rfkill_dev) 137 return -ENOMEM; 138 139 ret = rfkill_register(rfkill->rfkill_dev); 140 if (ret < 0) 141 return ret; 142 143 platform_set_drvdata(pdev, rfkill); 144 145 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); 146 147 return 0; 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 acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev)); 158 159 return 0; 160 } 161 162 #ifdef CONFIG_ACPI 163 static const struct acpi_device_id rfkill_acpi_match[] = { 164 { "BCM4752", RFKILL_TYPE_GPS }, 165 { "LNV4752", RFKILL_TYPE_GPS }, 166 { }, 167 }; 168 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match); 169 #endif 170 171 static struct platform_driver rfkill_gpio_driver = { 172 .probe = rfkill_gpio_probe, 173 .remove = rfkill_gpio_remove, 174 .driver = { 175 .name = "rfkill_gpio", 176 .acpi_match_table = ACPI_PTR(rfkill_acpi_match), 177 }, 178 }; 179 180 module_platform_driver(rfkill_gpio_driver); 181 182 MODULE_DESCRIPTION("gpio rfkill"); 183 MODULE_AUTHOR("NVIDIA"); 184 MODULE_LICENSE("GPL"); 185