input/misc/kxtj9.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2011 Kionix, Inc.
0004  * Written by Chris Hudson <chudson@kionix.com>
0005  */
0006
0007 #include <linux/delay.h>
0008 #include <linux/i2c.h>
0009 #include <linux/input.h>
0010 #include <linux/interrupt.h>
0011 #include <linux/module.h>
0012 #include <linux/slab.h>
0013 #include <linux/input/kxtj9.h>
0014
0015 #define NAME            "kxtj9"
0016 #define G_MAX           8000
0017 /* OUTPUT REGISTERS */
0018 #define XOUT_L          0x06
0019 #define WHO_AM_I        0x0F
0020 /* CONTROL REGISTERS */
0021 #define INT_REL         0x1A
0022 #define CTRL_REG1       0x1B
0023 #define INT_CTRL1       0x1E
0024 #define DATA_CTRL       0x21
0025 /* CONTROL REGISTER 1 BITS */
0026 #define PC1_OFF         0x7F
0027 #define PC1_ON          (1 << 7)
0028 /* Data ready funtion enable bit: set during probe if using irq mode */
0029 #define DRDYE           (1 << 5)
0030 /* DATA CONTROL REGISTER BITS */
0031 #define ODR12_5F        0
0032 #define ODR25F          1
0033 #define ODR50F          2
0034 #define ODR100F     3
0035 #define ODR200F     4
0036 #define ODR400F     5
0037 #define ODR800F     6
0038 /* INTERRUPT CONTROL REGISTER 1 BITS */
0039 /* Set these during probe if using irq mode */
0040 #define KXTJ9_IEL       (1 << 3)
0041 #define KXTJ9_IEA       (1 << 4)
0042 #define KXTJ9_IEN       (1 << 5)
0043 /* INPUT_ABS CONSTANTS */
0044 #define FUZZ            3
0045 #define FLAT            3
0046 /* RESUME STATE INDICES */
0047 #define RES_DATA_CTRL       0
0048 #define RES_CTRL_REG1       1
0049 #define RES_INT_CTRL1       2
0050 #define RESUME_ENTRIES      3
0051
0052 /*
0053  * The following table lists the maximum appropriate poll interval for each
0054  * available output data rate.
0055  */
0056 static const struct {
0057     unsigned int cutoff;
0058     u8 mask;
0059 } kxtj9_odr_table[] = {
0060     { 3,    ODR800F },
0061     { 5,    ODR400F },
0062     { 10,   ODR200F },
0063     { 20,   ODR100F },
0064     { 40,   ODR50F  },
0065     { 80,   ODR25F  },
0066     { 0,    ODR12_5F},
0067 };
0068
0069 struct kxtj9_data {
0070     struct i2c_client *client;
0071     struct kxtj9_platform_data pdata;
0072     struct input_dev *input_dev;
0073     unsigned int last_poll_interval;
0074     u8 shift;
0075     u8 ctrl_reg1;
0076     u8 data_ctrl;
0077     u8 int_ctrl;
0078 };
0079
0080 static int kxtj9_i2c_read(struct kxtj9_data *tj9, u8 addr, u8 *data, int len)
0081 {
0082     struct i2c_msg msgs[] = {
0083         {
0084             .addr = tj9->client->addr,
0085             .flags = tj9->client->flags,
0086             .len = 1,
0087             .buf = &addr,
0088         },
0089         {
0090             .addr = tj9->client->addr,
0091             .flags = tj9->client->flags | I2C_M_RD,
0092             .len = len,
0093             .buf = data,
0094         },
0095     };
0096
0097     return i2c_transfer(tj9->client->adapter, msgs, 2);
0098 }
0099
0100 static void kxtj9_report_acceleration_data(struct kxtj9_data *tj9)
0101 {
0102     s16 acc_data[3]; /* Data bytes from hardware xL, xH, yL, yH, zL, zH */
0103     s16 x, y, z;
0104     int err;
0105
0106     err = kxtj9_i2c_read(tj9, XOUT_L, (u8 *)acc_data, 6);
0107     if (err < 0)
0108         dev_err(&tj9->client->dev, "accelerometer data read failed\n");
0109
0110     x = le16_to_cpu(acc_data[tj9->pdata.axis_map_x]);
0111     y = le16_to_cpu(acc_data[tj9->pdata.axis_map_y]);
0112     z = le16_to_cpu(acc_data[tj9->pdata.axis_map_z]);
0113
0114     x >>= tj9->shift;
0115     y >>= tj9->shift;
0116     z >>= tj9->shift;
0117
0118     input_report_abs(tj9->input_dev, ABS_X, tj9->pdata.negate_x ? -x : x);
0119     input_report_abs(tj9->input_dev, ABS_Y, tj9->pdata.negate_y ? -y : y);
0120     input_report_abs(tj9->input_dev, ABS_Z, tj9->pdata.negate_z ? -z : z);
0121     input_sync(tj9->input_dev);
0122 }
0123
0124 static irqreturn_t kxtj9_isr(int irq, void *dev)
0125 {
0126     struct kxtj9_data *tj9 = dev;
0127     int err;
0128
0129     /* data ready is the only possible interrupt type */
0130     kxtj9_report_acceleration_data(tj9);
0131
0132     err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
0133     if (err < 0)
0134         dev_err(&tj9->client->dev,
0135             "error clearing interrupt status: %d\n", err);
0136
0137     return IRQ_HANDLED;
0138 }
0139
0140 static int kxtj9_update_g_range(struct kxtj9_data *tj9, u8 new_g_range)
0141 {
0142     switch (new_g_range) {
0143     case KXTJ9_G_2G:
0144         tj9->shift = 4;
0145         break;
0146     case KXTJ9_G_4G:
0147         tj9->shift = 3;
0148         break;
0149     case KXTJ9_G_8G:
0150         tj9->shift = 2;
0151         break;
0152     default:
0153         return -EINVAL;
0154     }
0155
0156     tj9->ctrl_reg1 &= 0xe7;
0157     tj9->ctrl_reg1 |= new_g_range;
0158
0159     return 0;
0160 }
0161
0162 static int kxtj9_update_odr(struct kxtj9_data *tj9, unsigned int poll_interval)
0163 {
0164     int err;
0165     int i;
0166
0167     /* Use the lowest ODR that can support the requested poll interval */
0168     for (i = 0; i < ARRAY_SIZE(kxtj9_odr_table); i++) {
0169         tj9->data_ctrl = kxtj9_odr_table[i].mask;
0170         if (poll_interval < kxtj9_odr_table[i].cutoff)
0171             break;
0172     }
0173
0174     err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
0175     if (err < 0)
0176         return err;
0177
0178     err = i2c_smbus_write_byte_data(tj9->client, DATA_CTRL, tj9->data_ctrl);
0179     if (err < 0)
0180         return err;
0181
0182     err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
0183     if (err < 0)
0184         return err;
0185
0186     return 0;
0187 }
0188
0189 static int kxtj9_device_power_on(struct kxtj9_data *tj9)
0190 {
0191     if (tj9->pdata.power_on)
0192         return tj9->pdata.power_on();
0193
0194     return 0;
0195 }
0196
0197 static void kxtj9_device_power_off(struct kxtj9_data *tj9)
0198 {
0199     int err;
0200
0201     tj9->ctrl_reg1 &= PC1_OFF;
0202     err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
0203     if (err < 0)
0204         dev_err(&tj9->client->dev, "soft power off failed\n");
0205
0206     if (tj9->pdata.power_off)
0207         tj9->pdata.power_off();
0208 }
0209
0210 static int kxtj9_enable(struct kxtj9_data *tj9)
0211 {
0212     int err;
0213
0214     err = kxtj9_device_power_on(tj9);
0215     if (err < 0)
0216         return err;
0217
0218     /* ensure that PC1 is cleared before updating control registers */
0219     err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0);
0220     if (err < 0)
0221         return err;
0222
0223     /* only write INT_CTRL_REG1 if in irq mode */
0224     if (tj9->client->irq) {
0225         err = i2c_smbus_write_byte_data(tj9->client,
0226                         INT_CTRL1, tj9->int_ctrl);
0227         if (err < 0)
0228             return err;
0229     }
0230
0231     err = kxtj9_update_g_range(tj9, tj9->pdata.g_range);
0232     if (err < 0)
0233         return err;
0234
0235     /* turn on outputs */
0236     tj9->ctrl_reg1 |= PC1_ON;
0237     err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1);
0238     if (err < 0)
0239         return err;
0240
0241     err = kxtj9_update_odr(tj9, tj9->last_poll_interval);
0242     if (err < 0)
0243         return err;
0244
0245     /* clear initial interrupt if in irq mode */
0246     if (tj9->client->irq) {
0247         err = i2c_smbus_read_byte_data(tj9->client, INT_REL);
0248         if (err < 0) {
0249             dev_err(&tj9->client->dev,
0250                 "error clearing interrupt: %d\n", err);
0251             goto fail;
0252         }
0253     }
0254
0255     return 0;
0256
0257 fail:
0258     kxtj9_device_power_off(tj9);
0259     return err;
0260 }
0261
0262 static void kxtj9_disable(struct kxtj9_data *tj9)
0263 {
0264     kxtj9_device_power_off(tj9);
0265 }
0266
0267 static int kxtj9_input_open(struct input_dev *input)
0268 {
0269     struct kxtj9_data *tj9 = input_get_drvdata(input);
0270
0271     return kxtj9_enable(tj9);
0272 }
0273
0274 static void kxtj9_input_close(struct input_dev *dev)
0275 {
0276     struct kxtj9_data *tj9 = input_get_drvdata(dev);
0277
0278     kxtj9_disable(tj9);
0279 }
0280
0281 /*
0282  * When IRQ mode is selected, we need to provide an interface to allow the user
0283  * to change the output data rate of the part.  For consistency, we are using
0284  * the set_poll method, which accepts a poll interval in milliseconds, and then
0285  * calls update_odr() while passing this value as an argument.  In IRQ mode, the
0286  * data outputs will not be read AT the requested poll interval, rather, the
0287  * lowest ODR that can support the requested interval.  The client application
0288  * will be responsible for retrieving data from the input node at the desired
0289  * interval.
0290  */
0291
0292 /* Returns currently selected poll interval (in ms) */
0293 static ssize_t kxtj9_get_poll(struct device *dev,
0294                 struct device_attribute *attr, char *buf)
0295 {
0296     struct i2c_client *client = to_i2c_client(dev);
0297     struct kxtj9_data *tj9 = i2c_get_clientdata(client);
0298
0299     return sprintf(buf, "%d\n", tj9->last_poll_interval);
0300 }
0301
0302 /* Allow users to select a new poll interval (in ms) */
0303 static ssize_t kxtj9_set_poll(struct device *dev, struct device_attribute *attr,
0304                         const char *buf, size_t count)
0305 {
0306     struct i2c_client *client = to_i2c_client(dev);
0307     struct kxtj9_data *tj9 = i2c_get_clientdata(client);
0308     struct input_dev *input_dev = tj9->input_dev;
0309     unsigned int interval;
0310     int error;
0311
0312     error = kstrtouint(buf, 10, &interval);
0313     if (error < 0)
0314         return error;
0315
0316     /* Lock the device to prevent races with open/close (and itself) */
0317     mutex_lock(&input_dev->mutex);
0318
0319     disable_irq(client->irq);
0320
0321     /*
0322      * Set current interval to the greater of the minimum interval or
0323      * the requested interval
0324      */
0325     tj9->last_poll_interval = max(interval, tj9->pdata.min_interval);
0326
0327     kxtj9_update_odr(tj9, tj9->last_poll_interval);
0328
0329     enable_irq(client->irq);
0330     mutex_unlock(&input_dev->mutex);
0331
0332     return count;
0333 }
0334
0335 static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll);
0336
0337 static struct attribute *kxtj9_attributes[] = {
0338     &dev_attr_poll.attr,
0339     NULL
0340 };
0341
0342 static struct attribute_group kxtj9_attribute_group = {
0343     .attrs = kxtj9_attributes
0344 };
0345
0346 static void kxtj9_poll(struct input_dev *input)
0347 {
0348     struct kxtj9_data *tj9 = input_get_drvdata(input);
0349     unsigned int poll_interval = input_get_poll_interval(input);
0350
0351     kxtj9_report_acceleration_data(tj9);
0352
0353     if (poll_interval != tj9->last_poll_interval) {
0354         kxtj9_update_odr(tj9, poll_interval);
0355         tj9->last_poll_interval = poll_interval;
0356     }
0357 }
0358
0359 static void kxtj9_platform_exit(void *data)
0360 {
0361     struct kxtj9_data *tj9 = data;
0362
0363     if (tj9->pdata.exit)
0364         tj9->pdata.exit();
0365 }
0366
0367 static int kxtj9_verify(struct kxtj9_data *tj9)
0368 {
0369     int retval;
0370
0371     retval = kxtj9_device_power_on(tj9);
0372     if (retval < 0)
0373         return retval;
0374
0375     retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I);
0376     if (retval < 0) {
0377         dev_err(&tj9->client->dev, "read err int source\n");
0378         goto out;
0379     }
0380
0381     retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0;
0382
0383 out:
0384     kxtj9_device_power_off(tj9);
0385     return retval;
0386 }
0387
0388 static int kxtj9_probe(struct i2c_client *client,
0389                const struct i2c_device_id *id)
0390 {
0391     const struct kxtj9_platform_data *pdata =
0392             dev_get_platdata(&client->dev);
0393     struct kxtj9_data *tj9;
0394     struct input_dev *input_dev;
0395     int err;
0396
0397     if (!i2c_check_functionality(client->adapter,
0398                 I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) {
0399         dev_err(&client->dev, "client is not i2c capable\n");
0400         return -ENXIO;
0401     }
0402
0403     if (!pdata) {
0404         dev_err(&client->dev, "platform data is NULL; exiting\n");
0405         return -EINVAL;
0406     }
0407
0408     tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL);
0409     if (!tj9) {
0410         dev_err(&client->dev,
0411             "failed to allocate memory for module data\n");
0412         return -ENOMEM;
0413     }
0414
0415     tj9->client = client;
0416     tj9->pdata = *pdata;
0417
0418     if (pdata->init) {
0419         err = pdata->init();
0420         if (err < 0)
0421             return err;
0422     }
0423
0424     err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9);
0425     if (err)
0426         return err;
0427
0428     err = kxtj9_verify(tj9);
0429     if (err < 0) {
0430         dev_err(&client->dev, "device not recognized\n");
0431         return err;
0432     }
0433
0434     i2c_set_clientdata(client, tj9);
0435
0436     tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range;
0437     tj9->last_poll_interval = tj9->pdata.init_interval;
0438
0439     input_dev = devm_input_allocate_device(&client->dev);
0440     if (!input_dev) {
0441         dev_err(&client->dev, "input device allocate failed\n");
0442         return -ENOMEM;
0443     }
0444
0445     input_set_drvdata(input_dev, tj9);
0446     tj9->input_dev = input_dev;
0447
0448     input_dev->name = "kxtj9_accel";
0449     input_dev->id.bustype = BUS_I2C;
0450
0451     input_dev->open = kxtj9_input_open;
0452     input_dev->close = kxtj9_input_close;
0453
0454     input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT);
0455     input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT);
0456     input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT);
0457
0458     if (client->irq <= 0) {
0459         err = input_setup_polling(input_dev, kxtj9_poll);
0460         if (err)
0461             return err;
0462     }
0463
0464     err = input_register_device(input_dev);
0465     if (err) {
0466         dev_err(&client->dev,
0467             "unable to register input polled device %s: %d\n",
0468             input_dev->name, err);
0469         return err;
0470     }
0471
0472     if (client->irq) {
0473         /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */
0474         tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL;
0475         tj9->ctrl_reg1 |= DRDYE;
0476
0477         err = devm_request_threaded_irq(&client->dev, client->irq,
0478                         NULL, kxtj9_isr,
0479                         IRQF_TRIGGER_RISING |
0480                             IRQF_ONESHOT,
0481                         "kxtj9-irq", tj9);
0482         if (err) {
0483             dev_err(&client->dev, "request irq failed: %d\n", err);
0484             return err;
0485         }
0486
0487         err = devm_device_add_group(&client->dev,
0488                         &kxtj9_attribute_group);
0489         if (err) {
0490             dev_err(&client->dev, "sysfs create failed: %d\n", err);
0491             return err;
0492         }
0493     }
0494
0495     return 0;
0496 }
0497
0498 static int __maybe_unused kxtj9_suspend(struct device *dev)
0499 {
0500     struct i2c_client *client = to_i2c_client(dev);
0501     struct kxtj9_data *tj9 = i2c_get_clientdata(client);
0502     struct input_dev *input_dev = tj9->input_dev;
0503
0504     mutex_lock(&input_dev->mutex);
0505
0506     if (input_device_enabled(input_dev))
0507         kxtj9_disable(tj9);
0508
0509     mutex_unlock(&input_dev->mutex);
0510     return 0;
0511 }
0512
0513 static int __maybe_unused kxtj9_resume(struct device *dev)
0514 {
0515     struct i2c_client *client = to_i2c_client(dev);
0516     struct kxtj9_data *tj9 = i2c_get_clientdata(client);
0517     struct input_dev *input_dev = tj9->input_dev;
0518
0519     mutex_lock(&input_dev->mutex);
0520
0521     if (input_device_enabled(input_dev))
0522         kxtj9_enable(tj9);
0523
0524     mutex_unlock(&input_dev->mutex);
0525     return 0;
0526 }
0527
0528 static SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume);
0529
0530 static const struct i2c_device_id kxtj9_id[] = {
0531     { NAME, 0 },
0532     { },
0533 };
0534
0535 MODULE_DEVICE_TABLE(i2c, kxtj9_id);
0536
0537 static struct i2c_driver kxtj9_driver = {
0538     .driver = {
0539         .name   = NAME,
0540         .pm = &kxtj9_pm_ops,
0541     },
0542     .probe      = kxtj9_probe,
0543     .id_table   = kxtj9_id,
0544 };
0545
0546 module_i2c_driver(kxtj9_driver);
0547
0548 MODULE_DESCRIPTION("KXTJ9 accelerometer driver");
0549 MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>");
0550 MODULE_LICENSE("GPL");