drivers/input/keyboard/ep93xx_keypad.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for the Cirrus EP93xx matrix keypad controller.
   4  *
   5  * Copyright (c) 2008 H Hartley Sweeten <hsweeten@visionengravers.com>
   6  *
   7  * Based on the pxa27x matrix keypad controller by Rodolfo Giometti.
   8  *
   9  */
  10
  11 #include <linux/bits.h>
  12 #include <linux/mod_devicetable.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/property.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/clk.h>
  18 #include <linux/io.h>
  19 #include <linux/input.h>
  20 #include <linux/input/matrix_keypad.h>
  21 #include <linux/slab.h>
  22 #include <linux/soc/cirrus/ep93xx.h>
  23 #include <linux/pm_wakeirq.h>
  24
  25 /*
  26  * Keypad Interface Register offsets
  27  */
  28 #define KEY_INIT                0x00    /* Key Scan Initialization register */
  29 #define KEY_DIAG                0x04    /* Key Scan Diagnostic register */
  30 #define KEY_REG                 0x08    /* Key Value Capture register */
  31
  32 /* Key Scan Initialization Register bit defines */
  33 #define KEY_INIT_DBNC_MASK      GENMASK(23, 16)
  34 #define KEY_INIT_DBNC_SHIFT     16
  35 #define KEY_INIT_DIS3KY         BIT(15)
  36 #define KEY_INIT_DIAG           BIT(14)
  37 #define KEY_INIT_BACK           BIT(13)
  38 #define KEY_INIT_T2             BIT(12)
  39 #define KEY_INIT_PRSCL_MASK     GENMASK(9, 0)
  40 #define KEY_INIT_PRSCL_SHIFT    0
  41
  42 /* Key Scan Diagnostic Register bit defines */
  43 #define KEY_DIAG_MASK           GENMASK(5, 0)
  44 #define KEY_DIAG_SHIFT          0
  45
  46 /* Key Value Capture Register bit defines */
  47 #define KEY_REG_K               BIT(15)
  48 #define KEY_REG_INT             BIT(14)
  49 #define KEY_REG_2KEYS           BIT(13)
  50 #define KEY_REG_1KEY            BIT(12)
  51 #define KEY_REG_KEY2_MASK       GENMASK(11, 6)
  52 #define KEY_REG_KEY2_SHIFT      6
  53 #define KEY_REG_KEY1_MASK       GENMASK(5, 0)
  54 #define KEY_REG_KEY1_SHIFT      0
  55
  56 #define EP93XX_MATRIX_ROWS              (8)
  57 #define EP93XX_MATRIX_COLS              (8)
  58
  59 #define EP93XX_MATRIX_SIZE      (EP93XX_MATRIX_ROWS * EP93XX_MATRIX_COLS)
  60
  61 struct ep93xx_keypad {
  62         struct input_dev *input_dev;
  63         struct clk *clk;
  64         unsigned int debounce;
  65         u16 prescale;
  66
  67         void __iomem *mmio_base;
  68
  69         unsigned short keycodes[EP93XX_MATRIX_SIZE];
  70
  71         int key1;
  72         int key2;
  73
  74         int irq;
  75
  76         bool enabled;
  77 };
  78
  79 static irqreturn_t ep93xx_keypad_irq_handler(int irq, void *dev_id)
  80 {
  81         struct ep93xx_keypad *keypad = dev_id;
  82         struct input_dev *input_dev = keypad->input_dev;
  83         unsigned int status;
  84         int keycode, key1, key2;
  85
  86         status = __raw_readl(keypad->mmio_base + KEY_REG);
  87
  88         keycode = (status & KEY_REG_KEY1_MASK) >> KEY_REG_KEY1_SHIFT;
  89         key1 = keypad->keycodes[keycode];
  90
  91         keycode = (status & KEY_REG_KEY2_MASK) >> KEY_REG_KEY2_SHIFT;
  92         key2 = keypad->keycodes[keycode];
  93
  94         if (status & KEY_REG_2KEYS) {
  95                 if (keypad->key1 && key1 != keypad->key1 && key2 != keypad->key1)
  96                         input_report_key(input_dev, keypad->key1, 0);
  97
  98                 if (keypad->key2 && key1 != keypad->key2 && key2 != keypad->key2)
  99                         input_report_key(input_dev, keypad->key2, 0);
 100
 101                 input_report_key(input_dev, key1, 1);
 102                 input_report_key(input_dev, key2, 1);
 103
 104                 keypad->key1 = key1;
 105                 keypad->key2 = key2;
 106
 107         } else if (status & KEY_REG_1KEY) {
 108                 if (keypad->key1 && key1 != keypad->key1)
 109                         input_report_key(input_dev, keypad->key1, 0);
 110
 111                 if (keypad->key2 && key1 != keypad->key2)
 112                         input_report_key(input_dev, keypad->key2, 0);
 113
 114                 input_report_key(input_dev, key1, 1);
 115
 116                 keypad->key1 = key1;
 117                 keypad->key2 = 0;
 118
 119         } else {
 120                 input_report_key(input_dev, keypad->key1, 0);
 121                 input_report_key(input_dev, keypad->key2, 0);
 122
 123                 keypad->key1 = keypad->key2 = 0;
 124         }
 125         input_sync(input_dev);
 126
 127         return IRQ_HANDLED;
 128 }
 129
 130 static void ep93xx_keypad_config(struct ep93xx_keypad *keypad)
 131 {
 132         unsigned int val = 0;
 133
 134         val |= (keypad->debounce << KEY_INIT_DBNC_SHIFT) & KEY_INIT_DBNC_MASK;
 135
 136         val |= (keypad->prescale << KEY_INIT_PRSCL_SHIFT) & KEY_INIT_PRSCL_MASK;
 137
 138         __raw_writel(val, keypad->mmio_base + KEY_INIT);
 139 }
 140
 141 static int ep93xx_keypad_open(struct input_dev *pdev)
 142 {
 143         struct ep93xx_keypad *keypad = input_get_drvdata(pdev);
 144
 145         if (!keypad->enabled) {
 146                 ep93xx_keypad_config(keypad);
 147                 clk_prepare_enable(keypad->clk);
 148                 keypad->enabled = true;
 149         }
 150
 151         return 0;
 152 }
 153
 154 static void ep93xx_keypad_close(struct input_dev *pdev)
 155 {
 156         struct ep93xx_keypad *keypad = input_get_drvdata(pdev);
 157
 158         if (keypad->enabled) {
 159                 clk_disable_unprepare(keypad->clk);
 160                 keypad->enabled = false;
 161         }
 162 }
 163
 164
 165 static int ep93xx_keypad_suspend(struct device *dev)
 166 {
 167         struct platform_device *pdev = to_platform_device(dev);
 168         struct ep93xx_keypad *keypad = platform_get_drvdata(pdev);
 169         struct input_dev *input_dev = keypad->input_dev;
 170
 171         guard(mutex)(&input_dev->mutex);
 172
 173         if (keypad->enabled) {
 174                 clk_disable(keypad->clk);
 175                 keypad->enabled = false;
 176         }
 177
 178         return 0;
 179 }
 180
 181 static int ep93xx_keypad_resume(struct device *dev)
 182 {
 183         struct platform_device *pdev = to_platform_device(dev);
 184         struct ep93xx_keypad *keypad = platform_get_drvdata(pdev);
 185         struct input_dev *input_dev = keypad->input_dev;
 186
 187         guard(mutex)(&input_dev->mutex);
 188
 189         if (input_device_enabled(input_dev)) {
 190                 if (!keypad->enabled) {
 191                         ep93xx_keypad_config(keypad);
 192                         clk_enable(keypad->clk);
 193                         keypad->enabled = true;
 194                 }
 195         }
 196
 197         return 0;
 198 }
 199
 200 static DEFINE_SIMPLE_DEV_PM_OPS(ep93xx_keypad_pm_ops,
 201                                 ep93xx_keypad_suspend, ep93xx_keypad_resume);
 202
 203 static int ep93xx_keypad_probe(struct platform_device *pdev)
 204 {
 205         struct device *dev = &pdev->dev;
 206         struct ep93xx_keypad *keypad;
 207         struct input_dev *input_dev;
 208         int err;
 209
 210         keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
 211         if (!keypad)
 212                 return -ENOMEM;
 213
 214         keypad->irq = platform_get_irq(pdev, 0);
 215         if (keypad->irq < 0)
 216                 return keypad->irq;
 217
 218         keypad->mmio_base = devm_platform_ioremap_resource(pdev, 0);
 219         if (IS_ERR(keypad->mmio_base))
 220                 return PTR_ERR(keypad->mmio_base);
 221
 222         keypad->clk = devm_clk_get(&pdev->dev, NULL);
 223         if (IS_ERR(keypad->clk))
 224                 return PTR_ERR(keypad->clk);
 225
 226         device_property_read_u32(dev, "debounce-delay-ms", &keypad->debounce);
 227         device_property_read_u16(dev, "cirrus,prescale", &keypad->prescale);
 228
 229         input_dev = devm_input_allocate_device(&pdev->dev);
 230         if (!input_dev)
 231                 return -ENOMEM;
 232
 233         keypad->input_dev = input_dev;
 234
 235         input_dev->name = pdev->name;
 236         input_dev->id.bustype = BUS_HOST;
 237         input_dev->open = ep93xx_keypad_open;
 238         input_dev->close = ep93xx_keypad_close;
 239
 240         err = matrix_keypad_build_keymap(NULL, NULL,
 241                                          EP93XX_MATRIX_ROWS, EP93XX_MATRIX_COLS,
 242                                          keypad->keycodes, input_dev);
 243         if (err)
 244                 return err;
 245
 246         if (device_property_read_bool(&pdev->dev, "autorepeat"))
 247                 __set_bit(EV_REP, input_dev->evbit);
 248         input_set_drvdata(input_dev, keypad);
 249
 250         err = devm_request_irq(&pdev->dev, keypad->irq,
 251                                ep93xx_keypad_irq_handler,
 252                                0, pdev->name, keypad);
 253         if (err)
 254                 return err;
 255
 256         err = input_register_device(input_dev);
 257         if (err)
 258                 return err;
 259
 260         platform_set_drvdata(pdev, keypad);
 261
 262         device_init_wakeup(&pdev->dev, 1);
 263         err = dev_pm_set_wake_irq(&pdev->dev, keypad->irq);
 264         if (err)
 265                 dev_warn(&pdev->dev, "failed to set up wakeup irq: %d\n", err);
 266
 267         return 0;
 268 }
 269
 270 static void ep93xx_keypad_remove(struct platform_device *pdev)
 271 {
 272         dev_pm_clear_wake_irq(&pdev->dev);
 273 }
 274
 275 static const struct of_device_id ep93xx_keypad_of_ids[] = {
 276         { .compatible = "cirrus,ep9307-keypad" },
 277         { /* sentinel */ }
 278 };
 279 MODULE_DEVICE_TABLE(of, ep93xx_keypad_of_ids);
 280
 281 static struct platform_driver ep93xx_keypad_driver = {
 282         .driver         = {
 283                 .name   = "ep93xx-keypad",
 284                 .pm     = pm_sleep_ptr(&ep93xx_keypad_pm_ops),
 285                 .of_match_table = ep93xx_keypad_of_ids,
 286         },
 287         .probe          = ep93xx_keypad_probe,
 288         .remove         = ep93xx_keypad_remove,
 289 };
 290 module_platform_driver(ep93xx_keypad_driver);
 291
 292 MODULE_LICENSE("GPL");
 293 MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
 294 MODULE_DESCRIPTION("EP93xx Matrix Keypad Controller");
 295 MODULE_ALIAS("platform:ep93xx-keypad");