linux/drivers/input/misc/axp20x-pek.c
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   1/*
   2 * axp20x power button driver.
   3 *
   4 * Copyright (C) 2013 Carlo Caione <carlo@caione.org>
   5 *
   6 * This file is subject to the terms and conditions of the GNU General
   7 * Public License. See the file "COPYING" in the main directory of this
   8 * archive for more details.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13 * GNU General Public License for more details.
  14 */
  15
  16#include <linux/errno.h>
  17#include <linux/irq.h>
  18#include <linux/init.h>
  19#include <linux/input.h>
  20#include <linux/interrupt.h>
  21#include <linux/kernel.h>
  22#include <linux/mfd/axp20x.h>
  23#include <linux/module.h>
  24#include <linux/platform_device.h>
  25#include <linux/regmap.h>
  26#include <linux/slab.h>
  27
  28#define AXP20X_PEK_STARTUP_MASK         (0xc0)
  29#define AXP20X_PEK_SHUTDOWN_MASK        (0x03)
  30
  31struct axp20x_pek {
  32        struct axp20x_dev *axp20x;
  33        struct input_dev *input;
  34        int irq_dbr;
  35        int irq_dbf;
  36};
  37
  38struct axp20x_time {
  39        unsigned int time;
  40        unsigned int idx;
  41};
  42
  43static const struct axp20x_time startup_time[] = {
  44        { .time = 128,  .idx = 0 },
  45        { .time = 1000, .idx = 2 },
  46        { .time = 3000, .idx = 1 },
  47        { .time = 2000, .idx = 3 },
  48};
  49
  50static const struct axp20x_time shutdown_time[] = {
  51        { .time = 4000,  .idx = 0 },
  52        { .time = 6000,  .idx = 1 },
  53        { .time = 8000,  .idx = 2 },
  54        { .time = 10000, .idx = 3 },
  55};
  56
  57struct axp20x_pek_ext_attr {
  58        const struct axp20x_time *p_time;
  59        unsigned int mask;
  60};
  61
  62static struct axp20x_pek_ext_attr axp20x_pek_startup_ext_attr = {
  63        .p_time = startup_time,
  64        .mask   = AXP20X_PEK_STARTUP_MASK,
  65};
  66
  67static struct axp20x_pek_ext_attr axp20x_pek_shutdown_ext_attr = {
  68        .p_time = shutdown_time,
  69        .mask   = AXP20X_PEK_SHUTDOWN_MASK,
  70};
  71
  72static struct axp20x_pek_ext_attr *get_axp_ext_attr(struct device_attribute *attr)
  73{
  74        return container_of(attr, struct dev_ext_attribute, attr)->var;
  75}
  76
  77static ssize_t axp20x_show_ext_attr(struct device *dev,
  78                                    struct device_attribute *attr, char *buf)
  79{
  80        struct axp20x_pek *axp20x_pek = dev_get_drvdata(dev);
  81        struct axp20x_pek_ext_attr *axp20x_ea = get_axp_ext_attr(attr);
  82        unsigned int val;
  83        int ret, i;
  84
  85        ret = regmap_read(axp20x_pek->axp20x->regmap, AXP20X_PEK_KEY, &val);
  86        if (ret != 0)
  87                return ret;
  88
  89        val &= axp20x_ea->mask;
  90        val >>= ffs(axp20x_ea->mask) - 1;
  91
  92        for (i = 0; i < 4; i++)
  93                if (val == axp20x_ea->p_time[i].idx)
  94                        val = axp20x_ea->p_time[i].time;
  95
  96        return sprintf(buf, "%u\n", val);
  97}
  98
  99static ssize_t axp20x_store_ext_attr(struct device *dev,
 100                                     struct device_attribute *attr,
 101                                     const char *buf, size_t count)
 102{
 103        struct axp20x_pek *axp20x_pek = dev_get_drvdata(dev);
 104        struct axp20x_pek_ext_attr *axp20x_ea = get_axp_ext_attr(attr);
 105        char val_str[20];
 106        size_t len;
 107        int ret, i;
 108        unsigned int val, idx = 0;
 109        unsigned int best_err = UINT_MAX;
 110
 111        val_str[sizeof(val_str) - 1] = '\0';
 112        strncpy(val_str, buf, sizeof(val_str) - 1);
 113        len = strlen(val_str);
 114
 115        if (len && val_str[len - 1] == '\n')
 116                val_str[len - 1] = '\0';
 117
 118        ret = kstrtouint(val_str, 10, &val);
 119        if (ret)
 120                return ret;
 121
 122        for (i = 3; i >= 0; i--) {
 123                unsigned int err;
 124
 125                err = abs(axp20x_ea->p_time[i].time - val);
 126                if (err < best_err) {
 127                        best_err = err;
 128                        idx = axp20x_ea->p_time[i].idx;
 129                }
 130
 131                if (!err)
 132                        break;
 133        }
 134
 135        idx <<= ffs(axp20x_ea->mask) - 1;
 136        ret = regmap_update_bits(axp20x_pek->axp20x->regmap,
 137                                 AXP20X_PEK_KEY,
 138                                 axp20x_ea->mask, idx);
 139        if (ret != 0)
 140                return -EINVAL;
 141
 142        return count;
 143}
 144
 145static struct dev_ext_attribute axp20x_dev_attr_startup = {
 146        .attr   = __ATTR(startup, 0644, axp20x_show_ext_attr, axp20x_store_ext_attr),
 147        .var    = &axp20x_pek_startup_ext_attr,
 148};
 149
 150static struct dev_ext_attribute axp20x_dev_attr_shutdown = {
 151        .attr   = __ATTR(shutdown, 0644, axp20x_show_ext_attr, axp20x_store_ext_attr),
 152        .var    = &axp20x_pek_shutdown_ext_attr,
 153};
 154
 155static struct attribute *axp20x_attributes[] = {
 156        &axp20x_dev_attr_startup.attr.attr,
 157        &axp20x_dev_attr_shutdown.attr.attr,
 158        NULL,
 159};
 160
 161static const struct attribute_group axp20x_attribute_group = {
 162        .attrs = axp20x_attributes,
 163};
 164
 165static irqreturn_t axp20x_pek_irq(int irq, void *pwr)
 166{
 167        struct input_dev *idev = pwr;
 168        struct axp20x_pek *axp20x_pek = input_get_drvdata(idev);
 169
 170        /*
 171         * The power-button is connected to ground so a falling edge (dbf)
 172         * means it is pressed.
 173         */
 174        if (irq == axp20x_pek->irq_dbf)
 175                input_report_key(idev, KEY_POWER, true);
 176        else if (irq == axp20x_pek->irq_dbr)
 177                input_report_key(idev, KEY_POWER, false);
 178
 179        input_sync(idev);
 180
 181        return IRQ_HANDLED;
 182}
 183
 184static void axp20x_remove_sysfs_group(void *_data)
 185{
 186        struct device *dev = _data;
 187
 188        sysfs_remove_group(&dev->kobj, &axp20x_attribute_group);
 189}
 190
 191static int axp20x_pek_probe(struct platform_device *pdev)
 192{
 193        struct axp20x_pek *axp20x_pek;
 194        struct axp20x_dev *axp20x;
 195        struct input_dev *idev;
 196        int error;
 197
 198        axp20x_pek = devm_kzalloc(&pdev->dev, sizeof(struct axp20x_pek),
 199                                  GFP_KERNEL);
 200        if (!axp20x_pek)
 201                return -ENOMEM;
 202
 203        axp20x_pek->axp20x = dev_get_drvdata(pdev->dev.parent);
 204        axp20x = axp20x_pek->axp20x;
 205
 206        axp20x_pek->irq_dbr = platform_get_irq_byname(pdev, "PEK_DBR");
 207        if (axp20x_pek->irq_dbr < 0) {
 208                dev_err(&pdev->dev, "No IRQ for PEK_DBR, error=%d\n",
 209                                axp20x_pek->irq_dbr);
 210                return axp20x_pek->irq_dbr;
 211        }
 212        axp20x_pek->irq_dbr = regmap_irq_get_virq(axp20x->regmap_irqc,
 213                                                  axp20x_pek->irq_dbr);
 214
 215        axp20x_pek->irq_dbf = platform_get_irq_byname(pdev, "PEK_DBF");
 216        if (axp20x_pek->irq_dbf < 0) {
 217                dev_err(&pdev->dev, "No IRQ for PEK_DBF, error=%d\n",
 218                                axp20x_pek->irq_dbf);
 219                return axp20x_pek->irq_dbf;
 220        }
 221        axp20x_pek->irq_dbf = regmap_irq_get_virq(axp20x->regmap_irqc,
 222                                                  axp20x_pek->irq_dbf);
 223
 224        axp20x_pek->input = devm_input_allocate_device(&pdev->dev);
 225        if (!axp20x_pek->input)
 226                return -ENOMEM;
 227
 228        idev = axp20x_pek->input;
 229
 230        idev->name = "axp20x-pek";
 231        idev->phys = "m1kbd/input2";
 232        idev->dev.parent = &pdev->dev;
 233
 234        input_set_capability(idev, EV_KEY, KEY_POWER);
 235
 236        input_set_drvdata(idev, axp20x_pek);
 237
 238        error = devm_request_any_context_irq(&pdev->dev, axp20x_pek->irq_dbr,
 239                                             axp20x_pek_irq, 0,
 240                                             "axp20x-pek-dbr", idev);
 241        if (error < 0) {
 242                dev_err(axp20x->dev, "Failed to request dbr IRQ#%d: %d\n",
 243                        axp20x_pek->irq_dbr, error);
 244                return error;
 245        }
 246
 247        error = devm_request_any_context_irq(&pdev->dev, axp20x_pek->irq_dbf,
 248                                          axp20x_pek_irq, 0,
 249                                          "axp20x-pek-dbf", idev);
 250        if (error < 0) {
 251                dev_err(axp20x->dev, "Failed to request dbf IRQ#%d: %d\n",
 252                        axp20x_pek->irq_dbf, error);
 253                return error;
 254        }
 255
 256        error = sysfs_create_group(&pdev->dev.kobj, &axp20x_attribute_group);
 257        if (error) {
 258                dev_err(axp20x->dev, "Failed to create sysfs attributes: %d\n",
 259                        error);
 260                return error;
 261        }
 262
 263        error = devm_add_action(&pdev->dev,
 264                                axp20x_remove_sysfs_group, &pdev->dev);
 265        if (error) {
 266                axp20x_remove_sysfs_group(&pdev->dev);
 267                dev_err(&pdev->dev, "Failed to add sysfs cleanup action: %d\n",
 268                        error);
 269                return error;
 270        }
 271
 272        error = input_register_device(idev);
 273        if (error) {
 274                dev_err(axp20x->dev, "Can't register input device: %d\n",
 275                        error);
 276                return error;
 277        }
 278
 279        platform_set_drvdata(pdev, axp20x_pek);
 280
 281        return 0;
 282}
 283
 284static struct platform_driver axp20x_pek_driver = {
 285        .probe          = axp20x_pek_probe,
 286        .driver         = {
 287                .name           = "axp20x-pek",
 288        },
 289};
 290module_platform_driver(axp20x_pek_driver);
 291
 292MODULE_DESCRIPTION("axp20x Power Button");
 293MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
 294MODULE_LICENSE("GPL");
 295MODULE_ALIAS("platform:axp20x-pek");
 296