kernel/drivers/input/keyboard/clps711x-keypad.c

   1 /*
   2  * Cirrus Logic CLPS711X Keypad driver
   3  *
   4  * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/input.h>
  13 #include <linux/input-polldev.h>
  14 #include <linux/module.h>
  15 #include <linux/of_gpio.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regmap.h>
  18 #include <linux/sched.h>
  19 #include <linux/input/matrix_keypad.h>
  20 #include <linux/mfd/syscon.h>
  21 #include <linux/mfd/syscon/clps711x.h>
  22
  23 #define CLPS711X_KEYPAD_COL_COUNT       8
  24
  25 struct clps711x_gpio_data {
  26         struct gpio_desc *desc;
  27         DECLARE_BITMAP(last_state, CLPS711X_KEYPAD_COL_COUNT);
  28 };
  29
  30 struct clps711x_keypad_data {
  31         struct regmap                   *syscon;
  32         int                             row_count;
  33         unsigned int                    row_shift;
  34         struct clps711x_gpio_data       *gpio_data;
  35 };
  36
  37 static void clps711x_keypad_poll(struct input_polled_dev *dev)
  38 {
  39         const unsigned short *keycodes = dev->input->keycode;
  40         struct clps711x_keypad_data *priv = dev->private;
  41         bool sync = false;
  42         int col, row;
  43
  44         for (col = 0; col < CLPS711X_KEYPAD_COL_COUNT; col++) {
  45                 /* Assert column */
  46                 regmap_update_bits(priv->syscon, SYSCON_OFFSET,
  47                                    SYSCON1_KBDSCAN_MASK,
  48                                    SYSCON1_KBDSCAN(8 + col));
  49
  50                 /* Scan rows */
  51                 for (row = 0; row < priv->row_count; row++) {
  52                         struct clps711x_gpio_data *data = &priv->gpio_data[row];
  53                         bool state, state1;
  54
  55                         /* Read twice for protection against fluctuations */
  56                         do {
  57                                 state = gpiod_get_value_cansleep(data->desc);
  58                                 cond_resched();
  59                                 state1 = gpiod_get_value_cansleep(data->desc);
  60                         } while (state != state1);
  61
  62                         if (test_bit(col, data->last_state) != state) {
  63                                 int code = MATRIX_SCAN_CODE(row, col,
  64                                                             priv->row_shift);
  65
  66                                 if (state) {
  67                                         set_bit(col, data->last_state);
  68                                         input_event(dev->input, EV_MSC,
  69                                                     MSC_SCAN, code);
  70                                 } else {
  71                                         clear_bit(col, data->last_state);
  72                                 }
  73
  74                                 if (keycodes[code])
  75                                         input_report_key(dev->input,
  76                                                          keycodes[code], state);
  77                                 sync = true;
  78                         }
  79                 }
  80
  81                 /* Set all columns to low */
  82                 regmap_update_bits(priv->syscon, SYSCON_OFFSET,
  83                                    SYSCON1_KBDSCAN_MASK, SYSCON1_KBDSCAN(1));
  84         }
  85
  86         if (sync)
  87                 input_sync(dev->input);
  88 }
  89
  90 static int clps711x_keypad_probe(struct platform_device *pdev)
  91 {
  92         struct clps711x_keypad_data *priv;
  93         struct device *dev = &pdev->dev;
  94         struct device_node *np = dev->of_node;
  95         struct input_polled_dev *poll_dev;
  96         u32 poll_interval;
  97         int i, err;
  98
  99         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 100         if (!priv)
 101                 return -ENOMEM;
 102
 103         priv->syscon =
 104                 syscon_regmap_lookup_by_compatible("cirrus,clps711x-syscon1");
 105         if (IS_ERR(priv->syscon))
 106                 return PTR_ERR(priv->syscon);
 107
 108         priv->row_count = of_gpio_named_count(np, "row-gpios");
 109         if (priv->row_count < 1)
 110                 return -EINVAL;
 111
 112         priv->gpio_data = devm_kzalloc(dev,
 113                                 sizeof(*priv->gpio_data) * priv->row_count,
 114                                 GFP_KERNEL);
 115         if (!priv->gpio_data)
 116                 return -ENOMEM;
 117
 118         priv->row_shift = get_count_order(CLPS711X_KEYPAD_COL_COUNT);
 119
 120         for (i = 0; i < priv->row_count; i++) {
 121                 struct clps711x_gpio_data *data = &priv->gpio_data[i];
 122
 123                 data->desc = devm_gpiod_get_index(dev, "row", i);
 124                 if (!data->desc)
 125                         return -EINVAL;
 126
 127                 if (IS_ERR(data->desc))
 128                         return PTR_ERR(data->desc);
 129
 130                 gpiod_direction_input(data->desc);
 131         }
 132
 133         err = of_property_read_u32(np, "poll-interval", &poll_interval);
 134         if (err)
 135                 return err;
 136
 137         poll_dev = input_allocate_polled_device();
 138         if (!poll_dev)
 139                 return -ENOMEM;
 140
 141         poll_dev->private               = priv;
 142         poll_dev->poll                  = clps711x_keypad_poll;
 143         poll_dev->poll_interval         = poll_interval;
 144         poll_dev->input->name           = pdev->name;
 145         poll_dev->input->dev.parent     = dev;
 146         poll_dev->input->id.bustype     = BUS_HOST;
 147         poll_dev->input->id.vendor      = 0x0001;
 148         poll_dev->input->id.product     = 0x0001;
 149         poll_dev->input->id.version     = 0x0100;
 150
 151         err = matrix_keypad_build_keymap(NULL, NULL, priv->row_count,
 152                                          CLPS711X_KEYPAD_COL_COUNT,
 153                                          NULL, poll_dev->input);
 154         if (err)
 155                 goto out_err;
 156
 157         input_set_capability(poll_dev->input, EV_MSC, MSC_SCAN);
 158         if (of_property_read_bool(np, "autorepeat"))
 159                 __set_bit(EV_REP, poll_dev->input->evbit);
 160
 161         platform_set_drvdata(pdev, poll_dev);
 162
 163         /* Set all columns to low */
 164         regmap_update_bits(priv->syscon, SYSCON_OFFSET, SYSCON1_KBDSCAN_MASK,
 165                            SYSCON1_KBDSCAN(1));
 166
 167         err = input_register_polled_device(poll_dev);
 168         if (err)
 169                 goto out_err;
 170
 171         return 0;
 172
 173 out_err:
 174         input_free_polled_device(poll_dev);
 175         return err;
 176 }
 177
 178 static int clps711x_keypad_remove(struct platform_device *pdev)
 179 {
 180         struct input_polled_dev *poll_dev = platform_get_drvdata(pdev);
 181
 182         input_unregister_polled_device(poll_dev);
 183         input_free_polled_device(poll_dev);
 184
 185         return 0;
 186 }
 187
 188 static const struct of_device_id clps711x_keypad_of_match[] = {
 189         { .compatible = "cirrus,clps711x-keypad", },
 190         { }
 191 };
 192 MODULE_DEVICE_TABLE(of, clps711x_keypad_of_match);
 193
 194 static struct platform_driver clps711x_keypad_driver = {
 195         .driver = {
 196                 .name           = "clps711x-keypad",
 197                 .of_match_table = clps711x_keypad_of_match,
 198         },
 199         .probe  = clps711x_keypad_probe,
 200         .remove = clps711x_keypad_remove,
 201 };
 202 module_platform_driver(clps711x_keypad_driver);
 203
 204 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
 205 MODULE_DESCRIPTION("Cirrus Logic CLPS711X Keypad driver");
 206 MODULE_LICENSE("GPL");