drivers/input/keyboard/st-keyscan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * STMicroelectronics Key Scanning driver
   4  *
   5  * Copyright (c) 2014 STMicroelectonics Ltd.
   6  * Author: Stuart Menefy <stuart.menefy@st.com>
   7  *
   8  * Based on sh_keysc.c, copyright 2008 Magnus Damm
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/clk.h>
  15 #include <linux/io.h>
  16 #include <linux/input/matrix_keypad.h>
  17
  18 #define ST_KEYSCAN_MAXKEYS 16
  19
  20 #define KEYSCAN_CONFIG_OFF              0x0
  21 #define KEYSCAN_CONFIG_ENABLE           0x1
  22 #define KEYSCAN_DEBOUNCE_TIME_OFF       0x4
  23 #define KEYSCAN_MATRIX_STATE_OFF        0x8
  24 #define KEYSCAN_MATRIX_DIM_OFF          0xc
  25 #define KEYSCAN_MATRIX_DIM_X_SHIFT      0x0
  26 #define KEYSCAN_MATRIX_DIM_Y_SHIFT      0x2
  27
  28 struct st_keyscan {
  29         void __iomem *base;
  30         int irq;
  31         struct clk *clk;
  32         struct input_dev *input_dev;
  33         unsigned long last_state;
  34         unsigned int n_rows;
  35         unsigned int n_cols;
  36         unsigned int debounce_us;
  37 };
  38
  39 static irqreturn_t keyscan_isr(int irq, void *dev_id)
  40 {
  41         struct st_keyscan *keypad = dev_id;
  42         unsigned short *keycode = keypad->input_dev->keycode;
  43         unsigned long state, change;
  44         int bit_nr;
  45
  46         state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff;
  47         change = keypad->last_state ^ state;
  48         keypad->last_state = state;
  49
  50         for_each_set_bit(bit_nr, &change, BITS_PER_LONG)
  51                 input_report_key(keypad->input_dev,
  52                                  keycode[bit_nr], state & BIT(bit_nr));
  53
  54         input_sync(keypad->input_dev);
  55
  56         return IRQ_HANDLED;
  57 }
  58
  59 static int keyscan_start(struct st_keyscan *keypad)
  60 {
  61         int error;
  62
  63         error = clk_enable(keypad->clk);
  64         if (error)
  65                 return error;
  66
  67         writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000),
  68                keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF);
  69
  70         writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) |
  71                ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT),
  72                keypad->base + KEYSCAN_MATRIX_DIM_OFF);
  73
  74         writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF);
  75
  76         return 0;
  77 }
  78
  79 static void keyscan_stop(struct st_keyscan *keypad)
  80 {
  81         writel(0, keypad->base + KEYSCAN_CONFIG_OFF);
  82
  83         clk_disable(keypad->clk);
  84 }
  85
  86 static int keyscan_open(struct input_dev *dev)
  87 {
  88         struct st_keyscan *keypad = input_get_drvdata(dev);
  89
  90         return keyscan_start(keypad);
  91 }
  92
  93 static void keyscan_close(struct input_dev *dev)
  94 {
  95         struct st_keyscan *keypad = input_get_drvdata(dev);
  96
  97         keyscan_stop(keypad);
  98 }
  99
 100 static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data)
 101 {
 102         struct device *dev = keypad_data->input_dev->dev.parent;
 103         struct device_node *np = dev->of_node;
 104         int error;
 105
 106         error = matrix_keypad_parse_properties(dev, &keypad_data->n_rows,
 107                                                &keypad_data->n_cols);
 108         if (error) {
 109                 dev_err(dev, "failed to parse keypad params\n");
 110                 return error;
 111         }
 112
 113         of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us);
 114
 115         dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n",
 116                 keypad_data->n_rows, keypad_data->n_cols,
 117                 keypad_data->debounce_us);
 118
 119         return 0;
 120 }
 121
 122 static int keyscan_probe(struct platform_device *pdev)
 123 {
 124         struct st_keyscan *keypad_data;
 125         struct input_dev *input_dev;
 126         struct resource *res;
 127         int error;
 128
 129         if (!pdev->dev.of_node) {
 130                 dev_err(&pdev->dev, "no DT data present\n");
 131                 return -EINVAL;
 132         }
 133
 134         keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data),
 135                                    GFP_KERNEL);
 136         if (!keypad_data)
 137                 return -ENOMEM;
 138
 139         input_dev = devm_input_allocate_device(&pdev->dev);
 140         if (!input_dev) {
 141                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 142                 return -ENOMEM;
 143         }
 144
 145         input_dev->name = pdev->name;
 146         input_dev->phys = "keyscan-keys/input0";
 147         input_dev->dev.parent = &pdev->dev;
 148         input_dev->open = keyscan_open;
 149         input_dev->close = keyscan_close;
 150
 151         input_dev->id.bustype = BUS_HOST;
 152
 153         keypad_data->input_dev = input_dev;
 154
 155         error = keypad_matrix_key_parse_dt(keypad_data);
 156         if (error)
 157                 return error;
 158
 159         error = matrix_keypad_build_keymap(NULL, NULL,
 160                                            keypad_data->n_rows,
 161                                            keypad_data->n_cols,
 162                                            NULL, input_dev);
 163         if (error) {
 164                 dev_err(&pdev->dev, "failed to build keymap\n");
 165                 return error;
 166         }
 167
 168         input_set_drvdata(input_dev, keypad_data);
 169
 170         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 171         keypad_data->base = devm_ioremap_resource(&pdev->dev, res);
 172         if (IS_ERR(keypad_data->base))
 173                 return PTR_ERR(keypad_data->base);
 174
 175         keypad_data->clk = devm_clk_get(&pdev->dev, NULL);
 176         if (IS_ERR(keypad_data->clk)) {
 177                 dev_err(&pdev->dev, "cannot get clock\n");
 178                 return PTR_ERR(keypad_data->clk);
 179         }
 180
 181         error = clk_enable(keypad_data->clk);
 182         if (error) {
 183                 dev_err(&pdev->dev, "failed to enable clock\n");
 184                 return error;
 185         }
 186
 187         keyscan_stop(keypad_data);
 188
 189         keypad_data->irq = platform_get_irq(pdev, 0);
 190         if (keypad_data->irq < 0) {
 191                 dev_err(&pdev->dev, "no IRQ specified\n");
 192                 return -EINVAL;
 193         }
 194
 195         error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0,
 196                                  pdev->name, keypad_data);
 197         if (error) {
 198                 dev_err(&pdev->dev, "failed to request IRQ\n");
 199                 return error;
 200         }
 201
 202         error = input_register_device(input_dev);
 203         if (error) {
 204                 dev_err(&pdev->dev, "failed to register input device\n");
 205                 return error;
 206         }
 207
 208         platform_set_drvdata(pdev, keypad_data);
 209
 210         device_set_wakeup_capable(&pdev->dev, 1);
 211
 212         return 0;
 213 }
 214
 215 #ifdef CONFIG_PM_SLEEP
 216 static int keyscan_suspend(struct device *dev)
 217 {
 218         struct platform_device *pdev = to_platform_device(dev);
 219         struct st_keyscan *keypad = platform_get_drvdata(pdev);
 220         struct input_dev *input = keypad->input_dev;
 221
 222         mutex_lock(&input->mutex);
 223
 224         if (device_may_wakeup(dev))
 225                 enable_irq_wake(keypad->irq);
 226         else if (input->users)
 227                 keyscan_stop(keypad);
 228
 229         mutex_unlock(&input->mutex);
 230         return 0;
 231 }
 232
 233 static int keyscan_resume(struct device *dev)
 234 {
 235         struct platform_device *pdev = to_platform_device(dev);
 236         struct st_keyscan *keypad = platform_get_drvdata(pdev);
 237         struct input_dev *input = keypad->input_dev;
 238         int retval = 0;
 239
 240         mutex_lock(&input->mutex);
 241
 242         if (device_may_wakeup(dev))
 243                 disable_irq_wake(keypad->irq);
 244         else if (input->users)
 245                 retval = keyscan_start(keypad);
 246
 247         mutex_unlock(&input->mutex);
 248         return retval;
 249 }
 250 #endif
 251
 252 static SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, keyscan_suspend, keyscan_resume);
 253
 254 static const struct of_device_id keyscan_of_match[] = {
 255         { .compatible = "st,sti-keyscan" },
 256         { },
 257 };
 258 MODULE_DEVICE_TABLE(of, keyscan_of_match);
 259
 260 static struct platform_driver keyscan_device_driver = {
 261         .probe          = keyscan_probe,
 262         .driver         = {
 263                 .name   = "st-keyscan",
 264                 .pm     = &keyscan_dev_pm_ops,
 265                 .of_match_table = of_match_ptr(keyscan_of_match),
 266         }
 267 };
 268
 269 module_platform_driver(keyscan_device_driver);
 270
 271 MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>");
 272 MODULE_DESCRIPTION("STMicroelectronics keyscan device driver");
 273 MODULE_LICENSE("GPL");