linux/drivers/input/keyboard/st-keyscan.c
<<
>>
Prefs
   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
  31struct 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
  42static 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
  62static 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
  82static void keyscan_stop(struct st_keyscan *keypad)
  83{
  84        writel(0, keypad->base + KEYSCAN_CONFIG_OFF);
  85
  86        clk_disable(keypad->clk);
  87}
  88
  89static 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
  96static void keyscan_close(struct input_dev *dev)
  97{
  98        struct st_keyscan *keypad = input_get_drvdata(dev);
  99
 100        keyscan_stop(keypad);
 101}
 102
 103static 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_of_params(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
 125static 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        error = keypad_matrix_key_parse_dt(keypad_data);
 157        if (error)
 158                return error;
 159
 160        error = matrix_keypad_build_keymap(NULL, NULL,
 161                                           keypad_data->n_rows,
 162                                           keypad_data->n_cols,
 163                                           NULL, input_dev);
 164        if (error) {
 165                dev_err(&pdev->dev, "failed to build keymap\n");
 166                return error;
 167        }
 168
 169        input_set_drvdata(input_dev, keypad_data);
 170
 171        keypad_data->input_dev = input_dev;
 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
 219static 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
 236static 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
 255static SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, keyscan_suspend, keyscan_resume);
 256
 257static const struct of_device_id keyscan_of_match[] = {
 258        { .compatible = "st,sti-keyscan" },
 259        { },
 260};
 261MODULE_DEVICE_TABLE(of, keyscan_of_match);
 262
 263static 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
 272module_platform_driver(keyscan_device_driver);
 273
 274MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>");
 275MODULE_DESCRIPTION("STMicroelectronics keyscan device driver");
 276MODULE_LICENSE("GPL");
 277
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.