input/keyboard/mt6779-keypad.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2022 MediaTek Inc.
0004  * Author Fengping Yu <fengping.yu@mediatek.com>
0005  */
0006 #include <linux/bitops.h>
0007 #include <linux/clk.h>
0008 #include <linux/input/matrix_keypad.h>
0009 #include <linux/interrupt.h>
0010 #include <linux/module.h>
0011 #include <linux/property.h>
0012 #include <linux/platform_device.h>
0013 #include <linux/regmap.h>
0014
0015 #define MTK_KPD_NAME        "mt6779-keypad"
0016 #define MTK_KPD_MEM     0x0004
0017 #define MTK_KPD_DEBOUNCE    0x0018
0018 #define MTK_KPD_DEBOUNCE_MASK   GENMASK(13, 0)
0019 #define MTK_KPD_DEBOUNCE_MAX_MS 256
0020 #define MTK_KPD_SEL     0x0020
0021 #define MTK_KPD_SEL_COL GENMASK(15, 10)
0022 #define MTK_KPD_SEL_ROW GENMASK(9, 4)
0023 #define MTK_KPD_SEL_COLMASK(c)  GENMASK((c) + 9, 10)
0024 #define MTK_KPD_SEL_ROWMASK(r)  GENMASK((r) + 3, 4)
0025 #define MTK_KPD_NUM_MEMS    5
0026 #define MTK_KPD_NUM_BITS    136 /* 4*32+8 MEM5 only use 8 BITS */
0027
0028 struct mt6779_keypad {
0029     struct regmap *regmap;
0030     struct input_dev *input_dev;
0031     struct clk *clk;
0032     u32 n_rows;
0033     u32 n_cols;
0034     DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
0035 };
0036
0037 static const struct regmap_config mt6779_keypad_regmap_cfg = {
0038     .reg_bits = 32,
0039     .val_bits = 32,
0040     .reg_stride = sizeof(u32),
0041     .max_register = 36,
0042 };
0043
0044 static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
0045 {
0046     struct mt6779_keypad *keypad = dev_id;
0047     const unsigned short *keycode = keypad->input_dev->keycode;
0048     DECLARE_BITMAP(new_state, MTK_KPD_NUM_BITS);
0049     DECLARE_BITMAP(change, MTK_KPD_NUM_BITS);
0050     unsigned int bit_nr, key;
0051     unsigned int row, col;
0052     unsigned int scancode;
0053     unsigned int row_shift = get_count_order(keypad->n_cols);
0054     bool pressed;
0055
0056     regmap_bulk_read(keypad->regmap, MTK_KPD_MEM,
0057              new_state, MTK_KPD_NUM_MEMS);
0058
0059     bitmap_xor(change, new_state, keypad->keymap_state, MTK_KPD_NUM_BITS);
0060
0061     for_each_set_bit(bit_nr, change, MTK_KPD_NUM_BITS) {
0062         /*
0063          * Registers are 32bits, but only bits [15:0] are used to
0064          * indicate key status.
0065          */
0066         if (bit_nr % 32 >= 16)
0067             continue;
0068
0069         key = bit_nr / 32 * 16 + bit_nr % 32;
0070         row = key / 9;
0071         col = key % 9;
0072
0073         scancode = MATRIX_SCAN_CODE(row, col, row_shift);
0074         /* 1: not pressed, 0: pressed */
0075         pressed = !test_bit(bit_nr, new_state);
0076         dev_dbg(&keypad->input_dev->dev, "%s",
0077             pressed ? "pressed" : "released");
0078
0079         input_event(keypad->input_dev, EV_MSC, MSC_SCAN, scancode);
0080         input_report_key(keypad->input_dev, keycode[scancode], pressed);
0081         input_sync(keypad->input_dev);
0082
0083         dev_dbg(&keypad->input_dev->dev,
0084             "report Linux keycode = %d\n", keycode[scancode]);
0085     }
0086
0087     bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
0088
0089     return IRQ_HANDLED;
0090 }
0091
0092 static void mt6779_keypad_clk_disable(void *data)
0093 {
0094     clk_disable_unprepare(data);
0095 }
0096
0097 static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
0098 {
0099     struct mt6779_keypad *keypad;
0100     void __iomem *base;
0101     int irq;
0102     u32 debounce;
0103     bool wakeup;
0104     int error;
0105
0106     keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
0107     if (!keypad)
0108         return -ENOMEM;
0109
0110     base = devm_platform_ioremap_resource(pdev, 0);
0111     if (IS_ERR(base))
0112         return PTR_ERR(base);
0113
0114     keypad->regmap = devm_regmap_init_mmio(&pdev->dev, base,
0115                            &mt6779_keypad_regmap_cfg);
0116     if (IS_ERR(keypad->regmap)) {
0117         dev_err(&pdev->dev,
0118             "regmap init failed:%pe\n", keypad->regmap);
0119         return PTR_ERR(keypad->regmap);
0120     }
0121
0122     bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
0123
0124     keypad->input_dev = devm_input_allocate_device(&pdev->dev);
0125     if (!keypad->input_dev) {
0126         dev_err(&pdev->dev, "Failed to allocate input dev\n");
0127         return -ENOMEM;
0128     }
0129
0130     keypad->input_dev->name = MTK_KPD_NAME;
0131     keypad->input_dev->id.bustype = BUS_HOST;
0132
0133     error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
0134                            &keypad->n_cols);
0135     if (error) {
0136         dev_err(&pdev->dev, "Failed to parse keypad params\n");
0137         return error;
0138     }
0139
0140     if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
0141                      &debounce))
0142         debounce = 16;
0143
0144     if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
0145         dev_err(&pdev->dev,
0146             "Debounce time exceeds the maximum allowed time %dms\n",
0147             MTK_KPD_DEBOUNCE_MAX_MS);
0148         return -EINVAL;
0149     }
0150
0151     wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
0152
0153     dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
0154         keypad->n_rows, keypad->n_cols, debounce);
0155
0156     error = matrix_keypad_build_keymap(NULL, NULL,
0157                        keypad->n_rows, keypad->n_cols,
0158                        NULL, keypad->input_dev);
0159     if (error) {
0160         dev_err(&pdev->dev, "Failed to build keymap\n");
0161         return error;
0162     }
0163
0164     input_set_capability(keypad->input_dev, EV_MSC, MSC_SCAN);
0165
0166     regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
0167              (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
0168
0169     regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_ROW,
0170                MTK_KPD_SEL_ROWMASK(keypad->n_rows));
0171     regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_COL,
0172                MTK_KPD_SEL_COLMASK(keypad->n_cols));
0173
0174     keypad->clk = devm_clk_get(&pdev->dev, "kpd");
0175     if (IS_ERR(keypad->clk))
0176         return PTR_ERR(keypad->clk);
0177
0178     error = clk_prepare_enable(keypad->clk);
0179     if (error) {
0180         dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
0181         return error;
0182     }
0183
0184     error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable,
0185                      keypad->clk);
0186     if (error)
0187         return error;
0188
0189     irq = platform_get_irq(pdev, 0);
0190     if (irq < 0)
0191         return irq;
0192
0193     error = devm_request_threaded_irq(&pdev->dev, irq,
0194                       NULL, mt6779_keypad_irq_handler,
0195                       IRQF_ONESHOT, MTK_KPD_NAME, keypad);
0196     if (error) {
0197         dev_err(&pdev->dev, "Failed to request IRQ#%d: %d\n",
0198             irq, error);
0199         return error;
0200     }
0201
0202     error = input_register_device(keypad->input_dev);
0203     if (error) {
0204         dev_err(&pdev->dev, "Failed to register device\n");
0205         return error;
0206     }
0207
0208     error = device_init_wakeup(&pdev->dev, wakeup);
0209     if (error)
0210         dev_warn(&pdev->dev, "device_init_wakeup() failed: %d\n",
0211              error);
0212
0213     return 0;
0214 }
0215
0216 static const struct of_device_id mt6779_keypad_of_match[] = {
0217     { .compatible = "mediatek,mt6779-keypad" },
0218     { .compatible = "mediatek,mt6873-keypad" },
0219     { /* sentinel */ }
0220 };
0221
0222 static struct platform_driver mt6779_keypad_pdrv = {
0223     .probe = mt6779_keypad_pdrv_probe,
0224     .driver = {
0225            .name = MTK_KPD_NAME,
0226            .of_match_table = mt6779_keypad_of_match,
0227     },
0228 };
0229 module_platform_driver(mt6779_keypad_pdrv);
0230
0231 MODULE_AUTHOR("Mediatek Corporation");
0232 MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
0233 MODULE_LICENSE("GPL");