drivers/input/keyboard/cypress-sf.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Cypress StreetFighter Touchkey Driver
   4  *
   5  * Copyright (c) 2021 Yassine Oudjana <y.oudjana@protonmail.com>
   6  */
   7
   8 #include <linux/bitmap.h>
   9 #include <linux/bitops.h>
  10 #include <linux/device.h>
  11 #include <linux/i2c.h>
  12 #include <linux/input.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/module.h>
  15 #include <linux/pm.h>
  16 #include <linux/regulator/consumer.h>
  17
  18 #define CYPRESS_SF_DEV_NAME "cypress-sf"
  19
  20 #define CYPRESS_SF_REG_BUTTON_STATUS    0x4a
  21
  22 struct cypress_sf_data {
  23         struct i2c_client *client;
  24         struct input_dev *input_dev;
  25         struct regulator_bulk_data regulators[2];
  26         u32 *keycodes;
  27         unsigned long keystates;
  28         int num_keys;
  29 };
  30
  31 static irqreturn_t cypress_sf_irq_handler(int irq, void *devid)
  32 {
  33         struct cypress_sf_data *touchkey = devid;
  34         unsigned long keystates, changed;
  35         bool new_state;
  36         int val, key;
  37
  38         val = i2c_smbus_read_byte_data(touchkey->client,
  39                                        CYPRESS_SF_REG_BUTTON_STATUS);
  40         if (val < 0) {
  41                 dev_err(&touchkey->client->dev,
  42                         "Failed to read button status: %d", val);
  43                 return IRQ_NONE;
  44         }
  45         keystates = val;
  46
  47         bitmap_xor(&changed, &keystates, &touchkey->keystates,
  48                    touchkey->num_keys);
  49
  50         for_each_set_bit(key, &changed, touchkey->num_keys) {
  51                 new_state = keystates & BIT(key);
  52                 dev_dbg(&touchkey->client->dev,
  53                         "Key %d changed to %d", key, new_state);
  54                 input_report_key(touchkey->input_dev,
  55                                  touchkey->keycodes[key], new_state);
  56         }
  57
  58         input_sync(touchkey->input_dev);
  59         touchkey->keystates = keystates;
  60
  61         return IRQ_HANDLED;
  62 }
  63
  64 static void cypress_sf_disable_regulators(void *arg)
  65 {
  66         struct cypress_sf_data *touchkey = arg;
  67
  68         regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
  69                                touchkey->regulators);
  70 }
  71
  72 static int cypress_sf_probe(struct i2c_client *client)
  73 {
  74         struct cypress_sf_data *touchkey;
  75         int key, error;
  76
  77         touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
  78         if (!touchkey)
  79                 return -ENOMEM;
  80
  81         touchkey->client = client;
  82         i2c_set_clientdata(client, touchkey);
  83
  84         touchkey->regulators[0].supply = "vdd";
  85         touchkey->regulators[1].supply = "avdd";
  86
  87         error = devm_regulator_bulk_get(&client->dev,
  88                                         ARRAY_SIZE(touchkey->regulators),
  89                                         touchkey->regulators);
  90         if (error) {
  91                 dev_err(&client->dev, "Failed to get regulators: %d\n", error);
  92                 return error;
  93         }
  94
  95         touchkey->num_keys = device_property_read_u32_array(&client->dev,
  96                                                             "linux,keycodes",
  97                                                             NULL, 0);
  98         if (touchkey->num_keys < 0) {
  99                 /* Default key count */
 100                 touchkey->num_keys = 2;
 101         }
 102
 103         touchkey->keycodes = devm_kcalloc(&client->dev,
 104                                           touchkey->num_keys,
 105                                           sizeof(*touchkey->keycodes),
 106                                           GFP_KERNEL);
 107         if (!touchkey->keycodes)
 108                 return -ENOMEM;
 109
 110         error = device_property_read_u32_array(&client->dev, "linux,keycodes",
 111                                                touchkey->keycodes,
 112                                                touchkey->num_keys);
 113
 114         if (error) {
 115                 dev_warn(&client->dev,
 116                          "Failed to read keycodes: %d, using defaults\n",
 117                          error);
 118
 119                 /* Default keycodes */
 120                 touchkey->keycodes[0] = KEY_BACK;
 121                 touchkey->keycodes[1] = KEY_MENU;
 122         }
 123
 124         error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
 125                                       touchkey->regulators);
 126         if (error) {
 127                 dev_err(&client->dev,
 128                         "Failed to enable regulators: %d\n", error);
 129                 return error;
 130         }
 131
 132         error = devm_add_action_or_reset(&client->dev,
 133                                          cypress_sf_disable_regulators,
 134                                          touchkey);
 135         if (error)
 136                 return error;
 137
 138         touchkey->input_dev = devm_input_allocate_device(&client->dev);
 139         if (!touchkey->input_dev) {
 140                 dev_err(&client->dev, "Failed to allocate input device\n");
 141                 return -ENOMEM;
 142         }
 143
 144         touchkey->input_dev->name = CYPRESS_SF_DEV_NAME;
 145         touchkey->input_dev->id.bustype = BUS_I2C;
 146
 147         for (key = 0; key < touchkey->num_keys; ++key)
 148                 input_set_capability(touchkey->input_dev,
 149                                      EV_KEY, touchkey->keycodes[key]);
 150
 151         error = input_register_device(touchkey->input_dev);
 152         if (error) {
 153                 dev_err(&client->dev,
 154                         "Failed to register input device: %d\n", error);
 155                 return error;
 156         }
 157
 158         error = devm_request_threaded_irq(&client->dev, client->irq,
 159                                           NULL, cypress_sf_irq_handler,
 160                                           IRQF_ONESHOT,
 161                                           CYPRESS_SF_DEV_NAME, touchkey);
 162         if (error) {
 163                 dev_err(&client->dev,
 164                         "Failed to register threaded irq: %d", error);
 165                 return error;
 166         }
 167
 168         return 0;
 169 };
 170
 171 static int cypress_sf_suspend(struct device *dev)
 172 {
 173         struct i2c_client *client = to_i2c_client(dev);
 174         struct cypress_sf_data *touchkey = i2c_get_clientdata(client);
 175         int error;
 176
 177         disable_irq(client->irq);
 178
 179         error = regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
 180                                        touchkey->regulators);
 181         if (error) {
 182                 dev_err(dev, "Failed to disable regulators: %d", error);
 183                 enable_irq(client->irq);
 184                 return error;
 185         }
 186
 187         return 0;
 188 }
 189
 190 static int cypress_sf_resume(struct device *dev)
 191 {
 192         struct i2c_client *client = to_i2c_client(dev);
 193         struct cypress_sf_data *touchkey = i2c_get_clientdata(client);
 194         int error;
 195
 196         error = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
 197                                       touchkey->regulators);
 198         if (error) {
 199                 dev_err(dev, "Failed to enable regulators: %d", error);
 200                 return error;
 201         }
 202
 203         enable_irq(client->irq);
 204
 205         return 0;
 206 }
 207
 208 static DEFINE_SIMPLE_DEV_PM_OPS(cypress_sf_pm_ops,
 209                                 cypress_sf_suspend, cypress_sf_resume);
 210
 211 static struct i2c_device_id cypress_sf_id_table[] = {
 212         { CYPRESS_SF_DEV_NAME },
 213         { }
 214 };
 215 MODULE_DEVICE_TABLE(i2c, cypress_sf_id_table);
 216
 217 #ifdef CONFIG_OF
 218 static const struct of_device_id cypress_sf_of_match[] = {
 219         { .compatible = "cypress,sf3155", },
 220         { },
 221 };
 222 MODULE_DEVICE_TABLE(of, cypress_sf_of_match);
 223 #endif
 224
 225 static struct i2c_driver cypress_sf_driver = {
 226         .driver = {
 227                 .name = CYPRESS_SF_DEV_NAME,
 228                 .pm = pm_sleep_ptr(&cypress_sf_pm_ops),
 229                 .of_match_table = of_match_ptr(cypress_sf_of_match),
 230         },
 231         .id_table = cypress_sf_id_table,
 232         .probe = cypress_sf_probe,
 233 };
 234 module_i2c_driver(cypress_sf_driver);
 235
 236 MODULE_AUTHOR("Yassine Oudjana <y.oudjana@protonmail.com>");
 237 MODULE_DESCRIPTION("Cypress StreetFighter Touchkey Driver");
 238 MODULE_LICENSE("GPL v2");