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 #include <linux/rfkill-gpio.h> 31 32 struct rfkill_gpio_data { 33 const char *name; 34 enum rfkill_type type; 35 struct gpio_desc *reset_gpio; 36 struct gpio_desc *shutdown_gpio; 37 38 struct rfkill *rfkill_dev; 39 struct clk *clk; 40 41 bool clk_enabled; 42 }; 43 44 static int rfkill_gpio_set_power(void *data, bool blocked) 45 { 46 struct rfkill_gpio_data *rfkill = data; 47 48 if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) 49 clk_enable(rfkill->clk); 50 51 gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked); 52 gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked); 53 54 if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled) 55 clk_disable(rfkill->clk); 56 57 rfkill->clk_enabled = !blocked; 58 59 return 0; 60 } 61 62 static const struct rfkill_ops rfkill_gpio_ops = { 63 .set_block = rfkill_gpio_set_power, 64 }; 65 66 static const struct acpi_gpio_params reset_gpios = { 0, 0, false }; 67 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false }; 68 69 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = { 70 { "reset-gpios", &reset_gpios, 1 }, 71 { "shutdown-gpios", &shutdown_gpios, 1 }, 72 { }, 73 }; 74 75 static int rfkill_gpio_acpi_probe(struct device *dev, 76 struct rfkill_gpio_data *rfkill) 77 { 78 const struct acpi_device_id *id; 79 80 id = acpi_match_device(dev->driver->acpi_match_table, dev); 81 if (!id) 82 return -ENODEV; 83 84 rfkill->name = dev_name(dev); 85 rfkill->type = (unsigned)id->driver_data; 86 87 return acpi_dev_add_driver_gpios(ACPI_COMPANION(dev), 88 acpi_rfkill_default_gpios); 89 } 90 91 static int rfkill_gpio_probe(struct platform_device *pdev) 92 { 93 struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data; 94 struct rfkill_gpio_data *rfkill; 95 struct gpio_desc *gpio; 96 int ret; 97 98 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL); 99 if (!rfkill) 100 return -ENOMEM; 101 102 if (ACPI_HANDLE(&pdev->dev)) { 103 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill); 104 if (ret) 105 return ret; 106 } else if (pdata) { 107 rfkill->name = pdata->name; 108 rfkill->type = pdata->type; 109 } else { 110 return -ENODEV; 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 of the GPIO is defined and that 128 * a name is specified for this instance 129 */ 130 if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) { 131 dev_err(&pdev->dev, "invalid platform data\n"); 132 return -EINVAL; 133 } 134 135 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev, 136 rfkill->type, &rfkill_gpio_ops, 137 rfkill); 138 if (!rfkill->rfkill_dev) 139 return -ENOMEM; 140 141 ret = rfkill_register(rfkill->rfkill_dev); 142 if (ret < 0) 143 return ret; 144 145 platform_set_drvdata(pdev, rfkill); 146 147 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name); 148 149 return 0; 150 } 151 152 static int rfkill_gpio_remove(struct platform_device *pdev) 153 { 154 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); 155 156 rfkill_unregister(rfkill->rfkill_dev); 157 rfkill_destroy(rfkill->rfkill_dev); 158 159 acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->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