1 /* 2 * HID over I2C Open Firmware Subclass 3 * 4 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com> 5 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France 6 * Copyright (c) 2012 Red Hat, Inc 7 * 8 * This code was forked out of the core code, which was partly based on 9 * "USB HID support for Linux": 10 * 11 * Copyright (c) 1999 Andreas Gal 12 * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz> 13 * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc 14 * Copyright (c) 2007-2008 Oliver Neukum 15 * Copyright (c) 2006-2010 Jiri Kosina 16 * 17 * This file is subject to the terms and conditions of the GNU General Public 18 * License. See the file COPYING in the main directory of this archive for 19 * more details. 20 */ 21 22 #include <linux/delay.h> 23 #include <linux/device.h> 24 #include <linux/gpio/consumer.h> 25 #include <linux/hid.h> 26 #include <linux/i2c.h> 27 #include <linux/kernel.h> 28 #include <linux/module.h> 29 #include <linux/of.h> 30 #include <linux/pm.h> 31 #include <linux/regulator/consumer.h> 32 33 #include "i2c-hid.h" 34 35 struct i2c_hid_of { 36 struct i2chid_ops ops; 37 38 struct i2c_client *client; 39 struct gpio_desc *reset_gpio; 40 struct regulator_bulk_data supplies[2]; 41 int post_power_delay_ms; 42 int post_reset_delay_ms; 43 }; 44 45 static int i2c_hid_of_power_up(struct i2chid_ops *ops) 46 { 47 struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops); 48 struct device *dev = &ihid_of->client->dev; 49 int ret; 50 51 ret = regulator_bulk_enable(ARRAY_SIZE(ihid_of->supplies), 52 ihid_of->supplies); 53 if (ret) { 54 dev_warn(dev, "Failed to enable supplies: %d\n", ret); 55 return ret; 56 } 57 58 if (ihid_of->post_power_delay_ms) 59 msleep(ihid_of->post_power_delay_ms); 60 61 gpiod_set_value_cansleep(ihid_of->reset_gpio, 0); 62 if (ihid_of->post_reset_delay_ms) 63 msleep(ihid_of->post_reset_delay_ms); 64 65 return 0; 66 } 67 68 static void i2c_hid_of_power_down(struct i2chid_ops *ops) 69 { 70 struct i2c_hid_of *ihid_of = container_of(ops, struct i2c_hid_of, ops); 71 72 gpiod_set_value_cansleep(ihid_of->reset_gpio, 1); 73 regulator_bulk_disable(ARRAY_SIZE(ihid_of->supplies), 74 ihid_of->supplies); 75 } 76 77 static int i2c_hid_of_probe(struct i2c_client *client) 78 { 79 struct device *dev = &client->dev; 80 struct i2c_hid_of *ihid_of; 81 u16 hid_descriptor_address; 82 u32 quirks = 0; 83 int ret; 84 u32 val; 85 86 ihid_of = devm_kzalloc(dev, sizeof(*ihid_of), GFP_KERNEL); 87 if (!ihid_of) 88 return -ENOMEM; 89 90 ihid_of->ops.power_up = i2c_hid_of_power_up; 91 ihid_of->ops.power_down = i2c_hid_of_power_down; 92 93 ret = device_property_read_u32(dev, "hid-descr-addr", &val); 94 if (ret) { 95 dev_err(dev, "HID register address not provided\n"); 96 return -ENODEV; 97 } 98 if (val >> 16) { 99 dev_err(dev, "Bad HID register address: 0x%08x\n", val); 100 return -EINVAL; 101 } 102 hid_descriptor_address = val; 103 104 if (!device_property_read_u32(dev, "post-power-on-delay-ms", &val)) 105 ihid_of->post_power_delay_ms = val; 106 107 /* 108 * Note this is a kernel internal device-property set by x86 platform code, 109 * this MUST not be used in devicetree files without first adding it to 110 * the DT bindings. 111 */ 112 if (!device_property_read_u32(dev, "post-reset-deassert-delay-ms", &val)) 113 ihid_of->post_reset_delay_ms = val; 114 115 /* Start out with reset asserted */ 116 ihid_of->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); 117 if (IS_ERR(ihid_of->reset_gpio)) 118 return PTR_ERR(ihid_of->reset_gpio); 119 120 ihid_of->supplies[0].supply = "vdd"; 121 ihid_of->supplies[1].supply = "vddl"; 122 ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ihid_of->supplies), 123 ihid_of->supplies); 124 if (ret) 125 return ret; 126 127 if (device_property_read_bool(dev, "touchscreen-inverted-x")) 128 quirks |= HID_QUIRK_X_INVERT; 129 130 if (device_property_read_bool(dev, "touchscreen-inverted-y")) 131 quirks |= HID_QUIRK_Y_INVERT; 132 133 return i2c_hid_core_probe(client, &ihid_of->ops, 134 hid_descriptor_address, quirks); 135 } 136 137 #ifdef CONFIG_OF 138 static const struct of_device_id i2c_hid_of_match[] = { 139 { .compatible = "hid-over-i2c" }, 140 {}, 141 }; 142 MODULE_DEVICE_TABLE(of, i2c_hid_of_match); 143 #endif 144 145 static const struct i2c_device_id i2c_hid_of_id_table[] = { 146 { "hid", 0 }, 147 { "hid-over-i2c", 0 }, 148 { }, 149 }; 150 MODULE_DEVICE_TABLE(i2c, i2c_hid_of_id_table); 151 152 static struct i2c_driver i2c_hid_of_driver = { 153 .driver = { 154 .name = "i2c_hid_of", 155 .pm = &i2c_hid_core_pm, 156 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 157 .of_match_table = of_match_ptr(i2c_hid_of_match), 158 }, 159 160 .probe_new = i2c_hid_of_probe, 161 .remove = i2c_hid_core_remove, 162 .shutdown = i2c_hid_core_shutdown, 163 .id_table = i2c_hid_of_id_table, 164 }; 165 166 module_i2c_driver(i2c_hid_of_driver); 167 168 MODULE_DESCRIPTION("HID over I2C OF driver"); 169 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 170 MODULE_LICENSE("GPL"); 171