drivers/input/keyboard/clps711x-keypad.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Cirrus Logic CLPS711X Keypad driver
   4  *
   5  * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
   6  */
   7
   8 #include <linux/input.h>
   9 #include <linux/module.h>
  10 #include <linux/of_gpio.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regmap.h>
  13 #include <linux/sched.h>
  14 #include <linux/input/matrix_keypad.h>
  15 #include <linux/mfd/syscon.h>
  16 #include <linux/mfd/syscon/clps711x.h>
  17
  18 #define CLPS711X_KEYPAD_COL_COUNT       8
  19
  20 struct clps711x_gpio_data {
  21         struct gpio_desc *desc;
  22         DECLARE_BITMAP(last_state, CLPS711X_KEYPAD_COL_COUNT);
  23 };
  24
  25 struct clps711x_keypad_data {
  26         struct regmap                   *syscon;
  27         int                             row_count;
  28         unsigned int                    row_shift;
  29         struct clps711x_gpio_data       *gpio_data;
  30 };
  31
  32 static void clps711x_keypad_poll(struct input_dev *input)
  33 {
  34         const unsigned short *keycodes = input->keycode;
  35         struct clps711x_keypad_data *priv = input_get_drvdata(input);
  36         bool sync = false;
  37         int col, row;
  38
  39         for (col = 0; col < CLPS711X_KEYPAD_COL_COUNT; col++) {
  40                 /* Assert column */
  41                 regmap_update_bits(priv->syscon, SYSCON_OFFSET,
  42                                    SYSCON1_KBDSCAN_MASK,
  43                                    SYSCON1_KBDSCAN(8 + col));
  44
  45                 /* Scan rows */
  46                 for (row = 0; row < priv->row_count; row++) {
  47                         struct clps711x_gpio_data *data = &priv->gpio_data[row];
  48                         bool state, state1;
  49
  50                         /* Read twice for protection against fluctuations */
  51                         do {
  52                                 state = gpiod_get_value_cansleep(data->desc);
  53                                 cond_resched();
  54                                 state1 = gpiod_get_value_cansleep(data->desc);
  55                         } while (state != state1);
  56
  57                         if (test_bit(col, data->last_state) != state) {
  58                                 int code = MATRIX_SCAN_CODE(row, col,
  59                                                             priv->row_shift);
  60
  61                                 if (state) {
  62                                         set_bit(col, data->last_state);
  63                                         input_event(input,
  64                                                     EV_MSC, MSC_SCAN, code);
  65                                 } else {
  66                                         clear_bit(col, data->last_state);
  67                                 }
  68
  69                                 if (keycodes[code])
  70                                         input_report_key(input,
  71                                                          keycodes[code], state);
  72                                 sync = true;
  73                         }
  74                 }
  75
  76                 /* Set all columns to low */
  77                 regmap_update_bits(priv->syscon, SYSCON_OFFSET,
  78                                    SYSCON1_KBDSCAN_MASK, SYSCON1_KBDSCAN(1));
  79         }
  80
  81         if (sync)
  82                 input_sync(input);
  83 }
  84
  85 static int clps711x_keypad_probe(struct platform_device *pdev)
  86 {
  87         struct clps711x_keypad_data *priv;
  88         struct device *dev = &pdev->dev;
  89         struct device_node *np = dev->of_node;
  90         struct input_dev *input;
  91         u32 poll_interval;
  92         int i, err;
  93
  94         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  95         if (!priv)
  96                 return -ENOMEM;
  97
  98         priv->syscon =
  99                 syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon1");
 100         if (IS_ERR(priv->syscon))
 101                 return PTR_ERR(priv->syscon);
 102
 103         priv->row_count = of_gpio_named_count(np, "row-gpios");
 104         if (priv->row_count < 1)
 105                 return -EINVAL;
 106
 107         priv->gpio_data = devm_kcalloc(dev,
 108                                 priv->row_count, sizeof(*priv->gpio_data),
 109                                 GFP_KERNEL);
 110         if (!priv->gpio_data)
 111                 return -ENOMEM;
 112
 113         priv->row_shift = get_count_order(CLPS711X_KEYPAD_COL_COUNT);
 114
 115         for (i = 0; i < priv->row_count; i++) {
 116                 struct clps711x_gpio_data *data = &priv->gpio_data[i];
 117
 118                 data->desc = devm_gpiod_get_index(dev, "row", i, GPIOD_IN);
 119                 if (IS_ERR(data->desc))
 120                         return PTR_ERR(data->desc);
 121         }
 122
 123         err = of_property_read_u32(np, "poll-interval", &poll_interval);
 124         if (err)
 125                 return err;
 126
 127         input = devm_input_allocate_device(dev);
 128         if (!input)
 129                 return -ENOMEM;
 130
 131         input_set_drvdata(input, priv);
 132
 133         input->name             = pdev->name;
 134         input->dev.parent       = dev;
 135         input->id.bustype       = BUS_HOST;
 136         input->id.vendor        = 0x0001;
 137         input->id.product       = 0x0001;
 138         input->id.version       = 0x0100;
 139
 140         err = matrix_keypad_build_keymap(NULL, NULL, priv->row_count,
 141                                          CLPS711X_KEYPAD_COL_COUNT,
 142                                          NULL, input);
 143         if (err)
 144                 return err;
 145
 146         input_set_capability(input, EV_MSC, MSC_SCAN);
 147         if (of_property_read_bool(np, "autorepeat"))
 148                 __set_bit(EV_REP, input->evbit);
 149
 150         /* Set all columns to low */
 151         regmap_update_bits(priv->syscon, SYSCON_OFFSET, SYSCON1_KBDSCAN_MASK,
 152                            SYSCON1_KBDSCAN(1));
 153
 154
 155         err = input_setup_polling(input, clps711x_keypad_poll);
 156         if (err)
 157                 return err;
 158
 159         input_set_poll_interval(input, poll_interval);
 160
 161         err = input_register_device(input);
 162         if (err)
 163                 return err;
 164
 165         return 0;
 166 }
 167
 168 static const struct of_device_id clps711x_keypad_of_match[] = {
 169         { .compatible = "cirrus,ep7209-keypad", },
 170         { }
 171 };
 172 MODULE_DEVICE_TABLE(of, clps711x_keypad_of_match);
 173
 174 static struct platform_driver clps711x_keypad_driver = {
 175         .driver = {
 176                 .name           = "clps711x-keypad",
 177                 .of_match_table = clps711x_keypad_of_match,
 178         },
 179         .probe  = clps711x_keypad_probe,
 180 };
 181 module_platform_driver(clps711x_keypad_driver);
 182
 183 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
 184 MODULE_DESCRIPTION("Cirrus Logic CLPS711X Keypad driver");
 185 MODULE_LICENSE("GPL");