drivers/input/keyboard/st-keyscan.c

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