drivers/input/keyboard/mt6779-keypad.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2022 MediaTek Inc.
   4  * Author Fengping Yu <fengping.yu@mediatek.com>
   5  */
   6 #include <linux/bitops.h>
   7 #include <linux/clk.h>
   8 #include <linux/input.h>
   9 #include <linux/input/matrix_keypad.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/module.h>
  12 #include <linux/property.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regmap.h>
  15
  16 #define MTK_KPD_NAME            "mt6779-keypad"
  17 #define MTK_KPD_MEM             0x0004
  18 #define MTK_KPD_DEBOUNCE        0x0018
  19 #define MTK_KPD_DEBOUNCE_MASK   GENMASK(13, 0)
  20 #define MTK_KPD_DEBOUNCE_MAX_MS 256
  21 #define MTK_KPD_SEL             0x0020
  22 #define MTK_KPD_SEL_DOUBLE_KP_MODE      BIT(0)
  23 #define MTK_KPD_SEL_COL GENMASK(15, 10)
  24 #define MTK_KPD_SEL_ROW GENMASK(9, 4)
  25 #define MTK_KPD_SEL_COLMASK(c)  GENMASK((c) + 9, 10)
  26 #define MTK_KPD_SEL_ROWMASK(r)  GENMASK((r) + 3, 4)
  27 #define MTK_KPD_NUM_MEMS        5
  28 #define MTK_KPD_NUM_BITS        136     /* 4*32+8 MEM5 only use 8 BITS */
  29
  30 struct mt6779_keypad {
  31         struct regmap *regmap;
  32         struct input_dev *input_dev;
  33         struct clk *clk;
  34         u32 n_rows;
  35         u32 n_cols;
  36         void (*calc_row_col)(unsigned int key,
  37                              unsigned int *row, unsigned int *col);
  38         DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
  39 };
  40
  41 static const struct regmap_config mt6779_keypad_regmap_cfg = {
  42         .reg_bits = 32,
  43         .val_bits = 32,
  44         .reg_stride = sizeof(u32),
  45         .max_register = 36,
  46 };
  47
  48 static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
  49 {
  50         struct mt6779_keypad *keypad = dev_id;
  51         const unsigned short *keycode = keypad->input_dev->keycode;
  52         DECLARE_BITMAP(new_state, MTK_KPD_NUM_BITS);
  53         DECLARE_BITMAP(change, MTK_KPD_NUM_BITS);
  54         unsigned int bit_nr, key;
  55         unsigned int row, col;
  56         unsigned int scancode;
  57         unsigned int row_shift = get_count_order(keypad->n_cols);
  58         bool pressed;
  59
  60         regmap_bulk_read(keypad->regmap, MTK_KPD_MEM,
  61                          new_state, MTK_KPD_NUM_MEMS);
  62
  63         bitmap_xor(change, new_state, keypad->keymap_state, MTK_KPD_NUM_BITS);
  64
  65         for_each_set_bit(bit_nr, change, MTK_KPD_NUM_BITS) {
  66                 /*
  67                  * Registers are 32bits, but only bits [15:0] are used to
  68                  * indicate key status.
  69                  */
  70                 if (bit_nr % 32 >= 16)
  71                         continue;
  72
  73                 key = bit_nr / 32 * 16 + bit_nr % 32;
  74                 keypad->calc_row_col(key, &row, &col);
  75
  76                 scancode = MATRIX_SCAN_CODE(row, col, row_shift);
  77                 /* 1: not pressed, 0: pressed */
  78                 pressed = !test_bit(bit_nr, new_state);
  79                 dev_dbg(&keypad->input_dev->dev, "%s",
  80                         pressed ? "pressed" : "released");
  81
  82                 input_event(keypad->input_dev, EV_MSC, MSC_SCAN, scancode);
  83                 input_report_key(keypad->input_dev, keycode[scancode], pressed);
  84                 input_sync(keypad->input_dev);
  85
  86                 dev_dbg(&keypad->input_dev->dev,
  87                         "report Linux keycode = %d\n", keycode[scancode]);
  88         }
  89
  90         bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
  91
  92         return IRQ_HANDLED;
  93 }
  94
  95 static void mt6779_keypad_clk_disable(void *data)
  96 {
  97         clk_disable_unprepare(data);
  98 }
  99
 100 static void mt6779_keypad_calc_row_col_single(unsigned int key,
 101                                               unsigned int *row,
 102                                               unsigned int *col)
 103 {
 104         *row = key / 9;
 105         *col = key % 9;
 106 }
 107
 108 static void mt6779_keypad_calc_row_col_double(unsigned int key,
 109                                               unsigned int *row,
 110                                               unsigned int *col)
 111 {
 112         *row = key / 13;
 113         *col = (key % 13) / 2;
 114 }
 115
 116 static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
 117 {
 118         struct mt6779_keypad *keypad;
 119         void __iomem *base;
 120         int irq;
 121         u32 debounce;
 122         u32 keys_per_group;
 123         bool wakeup;
 124         int error;
 125
 126         keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
 127         if (!keypad)
 128                 return -ENOMEM;
 129
 130         base = devm_platform_ioremap_resource(pdev, 0);
 131         if (IS_ERR(base))
 132                 return PTR_ERR(base);
 133
 134         keypad->regmap = devm_regmap_init_mmio(&pdev->dev, base,
 135                                                &mt6779_keypad_regmap_cfg);
 136         if (IS_ERR(keypad->regmap)) {
 137                 dev_err(&pdev->dev,
 138                         "regmap init failed:%pe\n", keypad->regmap);
 139                 return PTR_ERR(keypad->regmap);
 140         }
 141
 142         bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
 143
 144         keypad->input_dev = devm_input_allocate_device(&pdev->dev);
 145         if (!keypad->input_dev) {
 146                 dev_err(&pdev->dev, "Failed to allocate input dev\n");
 147                 return -ENOMEM;
 148         }
 149
 150         keypad->input_dev->name = MTK_KPD_NAME;
 151         keypad->input_dev->id.bustype = BUS_HOST;
 152
 153         error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
 154                                                &keypad->n_cols);
 155         if (error) {
 156                 dev_err(&pdev->dev, "Failed to parse keypad params\n");
 157                 return error;
 158         }
 159
 160         if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
 161                                      &debounce))
 162                 debounce = 16;
 163
 164         if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
 165                 dev_err(&pdev->dev,
 166                         "Debounce time exceeds the maximum allowed time %dms\n",
 167                         MTK_KPD_DEBOUNCE_MAX_MS);
 168                 return -EINVAL;
 169         }
 170
 171         if (device_property_read_u32(&pdev->dev, "mediatek,keys-per-group",
 172                                      &keys_per_group))
 173                 keys_per_group = 1;
 174
 175         switch (keys_per_group) {
 176         case 1:
 177                 keypad->calc_row_col = mt6779_keypad_calc_row_col_single;
 178                 break;
 179         case 2:
 180                 keypad->calc_row_col = mt6779_keypad_calc_row_col_double;
 181                 break;
 182         default:
 183                 dev_err(&pdev->dev,
 184                         "Invalid keys-per-group: %d\n", keys_per_group);
 185                 return -EINVAL;
 186         }
 187
 188         wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
 189
 190         dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
 191                 keypad->n_rows, keypad->n_cols, debounce);
 192
 193         error = matrix_keypad_build_keymap(NULL, NULL,
 194                                            keypad->n_rows, keypad->n_cols,
 195                                            NULL, keypad->input_dev);
 196         if (error) {
 197                 dev_err(&pdev->dev, "Failed to build keymap\n");
 198                 return error;
 199         }
 200
 201         input_set_capability(keypad->input_dev, EV_MSC, MSC_SCAN);
 202
 203         regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
 204                      (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
 205
 206         if (keys_per_group == 2)
 207                 regmap_update_bits(keypad->regmap, MTK_KPD_SEL,
 208                                    MTK_KPD_SEL_DOUBLE_KP_MODE,
 209                                    MTK_KPD_SEL_DOUBLE_KP_MODE);
 210
 211         regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_ROW,
 212                            MTK_KPD_SEL_ROWMASK(keypad->n_rows));
 213         regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_COL,
 214                            MTK_KPD_SEL_COLMASK(keypad->n_cols));
 215
 216         keypad->clk = devm_clk_get(&pdev->dev, "kpd");
 217         if (IS_ERR(keypad->clk))
 218                 return PTR_ERR(keypad->clk);
 219
 220         error = clk_prepare_enable(keypad->clk);
 221         if (error) {
 222                 dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
 223                 return error;
 224         }
 225
 226         error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable,
 227                                          keypad->clk);
 228         if (error)
 229                 return error;
 230
 231         irq = platform_get_irq(pdev, 0);
 232         if (irq < 0)
 233                 return irq;
 234
 235         error = devm_request_threaded_irq(&pdev->dev, irq,
 236                                           NULL, mt6779_keypad_irq_handler,
 237                                           IRQF_ONESHOT, MTK_KPD_NAME, keypad);
 238         if (error) {
 239                 dev_err(&pdev->dev, "Failed to request IRQ#%d: %d\n",
 240                         irq, error);
 241                 return error;
 242         }
 243
 244         error = input_register_device(keypad->input_dev);
 245         if (error) {
 246                 dev_err(&pdev->dev, "Failed to register device\n");
 247                 return error;
 248         }
 249
 250         error = device_init_wakeup(&pdev->dev, wakeup);
 251         if (error)
 252                 dev_warn(&pdev->dev, "device_init_wakeup() failed: %d\n",
 253                          error);
 254
 255         return 0;
 256 }
 257
 258 static const struct of_device_id mt6779_keypad_of_match[] = {
 259         { .compatible = "mediatek,mt6779-keypad" },
 260         { .compatible = "mediatek,mt6873-keypad" },
 261         { /* sentinel */ }
 262 };
 263
 264 static struct platform_driver mt6779_keypad_pdrv = {
 265         .probe = mt6779_keypad_pdrv_probe,
 266         .driver = {
 267                    .name = MTK_KPD_NAME,
 268                    .of_match_table = mt6779_keypad_of_match,
 269         },
 270 };
 271 module_platform_driver(mt6779_keypad_pdrv);
 272
 273 MODULE_AUTHOR("Mediatek Corporation");
 274 MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
 275 MODULE_LICENSE("GPL");