| 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"); |