input/touchscreen/sx8654.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Driver for Semtech SX8654 I2C touchscreen controller.
0004  *
0005  * Copyright (c) 2015 Armadeus Systems
0006  *  Sébastien Szymanski <sebastien.szymanski@armadeus.com>
0007  *
0008  * Using code from:
0009  *  - sx865x.c
0010  *  Copyright (c) 2013 U-MoBo Srl
0011  *  Pierluigi Passaro <p.passaro@u-mobo.com>
0012  *  - sx8650.c
0013  *      Copyright (c) 2009 Wayne Roberts
0014  *  - tsc2007.c
0015  *      Copyright (c) 2008 Kwangwoo Lee
0016  *  - ads7846.c
0017  *      Copyright (c) 2005 David Brownell
0018  *      Copyright (c) 2006 Nokia Corporation
0019  *  - corgi_ts.c
0020  *      Copyright (C) 2004-2005 Richard Purdie
0021  *  - omap_ts.[hc], ads7846.h, ts_osk.c
0022  *      Copyright (C) 2002 MontaVista Software
0023  *      Copyright (C) 2004 Texas Instruments
0024  *      Copyright (C) 2005 Dirk Behme
0025  */
0026
0027 #include <linux/bitops.h>
0028 #include <linux/delay.h>
0029 #include <linux/gpio/consumer.h>
0030 #include <linux/i2c.h>
0031 #include <linux/input.h>
0032 #include <linux/input/touchscreen.h>
0033 #include <linux/interrupt.h>
0034 #include <linux/irq.h>
0035 #include <linux/module.h>
0036 #include <linux/of.h>
0037
0038 /* register addresses */
0039 #define I2C_REG_TOUCH0          0x00
0040 #define I2C_REG_TOUCH1          0x01
0041 #define I2C_REG_CHANMASK        0x04
0042 #define I2C_REG_IRQMASK         0x22
0043 #define I2C_REG_IRQSRC          0x23
0044 #define I2C_REG_SOFTRESET       0x3f
0045
0046 #define I2C_REG_SX8650_STAT     0x05
0047 #define SX8650_STAT_CONVIRQ     BIT(7)
0048
0049 /* commands */
0050 #define CMD_READ_REGISTER       0x40
0051 #define CMD_PENTRG          0xe0
0052
0053 /* value for I2C_REG_SOFTRESET */
0054 #define SOFTRESET_VALUE         0xde
0055
0056 /* bits for I2C_REG_IRQSRC */
0057 #define IRQ_PENTOUCH_TOUCHCONVDONE  BIT(3)
0058 #define IRQ_PENRELEASE          BIT(2)
0059
0060 /* bits for RegTouch1 */
0061 #define CONDIRQ             0x20
0062 #define RPDNT_100K          0x00
0063 #define FILT_7SA            0x03
0064
0065 /* bits for I2C_REG_CHANMASK */
0066 #define CONV_X              BIT(7)
0067 #define CONV_Y              BIT(6)
0068
0069 /* coordinates rate: higher nibble of CTRL0 register */
0070 #define RATE_MANUAL         0x00
0071 #define RATE_5000CPS            0xf0
0072
0073 /* power delay: lower nibble of CTRL0 register */
0074 #define POWDLY_1_1MS            0x0b
0075
0076 /* for sx8650, as we have no pen release IRQ there: timeout in ns following the
0077  * last PENIRQ after which we assume the pen is lifted.
0078  */
0079 #define SX8650_PENIRQ_TIMEOUT       msecs_to_jiffies(10)
0080
0081 #define MAX_12BIT           ((1 << 12) - 1)
0082 #define MAX_I2C_READ_LEN        10 /* see datasheet section 5.1.5 */
0083
0084 /* channel definition */
0085 #define CH_X                0x00
0086 #define CH_Y                0x01
0087
0088 struct sx865x_data {
0089     u8 cmd_manual;
0090     u8 chan_mask;
0091     bool has_irq_penrelease;
0092     bool has_reg_irqmask;
0093     irq_handler_t irqh;
0094 };
0095
0096 struct sx8654 {
0097     struct input_dev *input;
0098     struct i2c_client *client;
0099     struct gpio_desc *gpio_reset;
0100
0101     spinlock_t lock;    /* for input reporting from irq/timer */
0102     struct timer_list timer;
0103
0104     struct touchscreen_properties props;
0105
0106     const struct sx865x_data *data;
0107 };
0108
0109 static inline void sx865x_penrelease(struct sx8654 *ts)
0110 {
0111     struct input_dev *input_dev = ts->input;
0112
0113     input_report_key(input_dev, BTN_TOUCH, 0);
0114     input_sync(input_dev);
0115 }
0116
0117 static void sx865x_penrelease_timer_handler(struct timer_list *t)
0118 {
0119     struct sx8654 *ts = from_timer(ts, t, timer);
0120     unsigned long flags;
0121
0122     spin_lock_irqsave(&ts->lock, flags);
0123     sx865x_penrelease(ts);
0124     spin_unlock_irqrestore(&ts->lock, flags);
0125     dev_dbg(&ts->client->dev, "penrelease by timer\n");
0126 }
0127
0128 static irqreturn_t sx8650_irq(int irq, void *handle)
0129 {
0130     struct sx8654 *ts = handle;
0131     struct device *dev = &ts->client->dev;
0132     int len, i;
0133     unsigned long flags;
0134     u8 stat;
0135     u16 x, y;
0136     u16 ch;
0137     u16 chdata;
0138     __be16 data[MAX_I2C_READ_LEN / sizeof(__be16)];
0139     u8 nchan = hweight32(ts->data->chan_mask);
0140     u8 readlen = nchan * sizeof(*data);
0141
0142     stat = i2c_smbus_read_byte_data(ts->client, CMD_READ_REGISTER
0143                             | I2C_REG_SX8650_STAT);
0144
0145     if (!(stat & SX8650_STAT_CONVIRQ)) {
0146         dev_dbg(dev, "%s ignore stat [0x%02x]", __func__, stat);
0147         return IRQ_HANDLED;
0148     }
0149
0150     len = i2c_master_recv(ts->client, (u8 *)data, readlen);
0151     if (len != readlen) {
0152         dev_dbg(dev, "ignore short recv (%d)\n", len);
0153         return IRQ_HANDLED;
0154     }
0155
0156     spin_lock_irqsave(&ts->lock, flags);
0157
0158     x = 0;
0159     y = 0;
0160     for (i = 0; i < nchan; i++) {
0161         chdata = be16_to_cpu(data[i]);
0162
0163         if (unlikely(chdata == 0xFFFF)) {
0164             dev_dbg(dev, "invalid qualified data @ %d\n", i);
0165             continue;
0166         } else if (unlikely(chdata & 0x8000)) {
0167             dev_warn(dev, "hibit @ %d [0x%04x]\n", i, chdata);
0168             continue;
0169         }
0170
0171         ch = chdata >> 12;
0172         if (ch == CH_X)
0173             x = chdata & MAX_12BIT;
0174         else if (ch == CH_Y)
0175             y = chdata & MAX_12BIT;
0176         else
0177             dev_warn(dev, "unknown channel %d [0x%04x]\n", ch,
0178                  chdata);
0179     }
0180
0181     touchscreen_report_pos(ts->input, &ts->props, x, y, false);
0182     input_report_key(ts->input, BTN_TOUCH, 1);
0183     input_sync(ts->input);
0184     dev_dbg(dev, "point(%4d,%4d)\n", x, y);
0185
0186     mod_timer(&ts->timer, jiffies + SX8650_PENIRQ_TIMEOUT);
0187     spin_unlock_irqrestore(&ts->lock, flags);
0188
0189     return IRQ_HANDLED;
0190 }
0191
0192 static irqreturn_t sx8654_irq(int irq, void *handle)
0193 {
0194     struct sx8654 *sx8654 = handle;
0195     int irqsrc;
0196     u8 data[4];
0197     unsigned int x, y;
0198     int retval;
0199
0200     irqsrc = i2c_smbus_read_byte_data(sx8654->client,
0201                       CMD_READ_REGISTER | I2C_REG_IRQSRC);
0202     dev_dbg(&sx8654->client->dev, "irqsrc = 0x%x", irqsrc);
0203
0204     if (irqsrc < 0)
0205         goto out;
0206
0207     if (irqsrc & IRQ_PENRELEASE) {
0208         dev_dbg(&sx8654->client->dev, "pen release interrupt");
0209
0210         input_report_key(sx8654->input, BTN_TOUCH, 0);
0211         input_sync(sx8654->input);
0212     }
0213
0214     if (irqsrc & IRQ_PENTOUCH_TOUCHCONVDONE) {
0215         dev_dbg(&sx8654->client->dev, "pen touch interrupt");
0216
0217         retval = i2c_master_recv(sx8654->client, data, sizeof(data));
0218         if (retval != sizeof(data))
0219             goto out;
0220
0221         /* invalid data */
0222         if (unlikely(data[0] & 0x80 || data[2] & 0x80))
0223             goto out;
0224
0225         x = ((data[0] & 0xf) << 8) | (data[1]);
0226         y = ((data[2] & 0xf) << 8) | (data[3]);
0227
0228         touchscreen_report_pos(sx8654->input, &sx8654->props, x, y,
0229                        false);
0230         input_report_key(sx8654->input, BTN_TOUCH, 1);
0231         input_sync(sx8654->input);
0232
0233         dev_dbg(&sx8654->client->dev, "point(%4d,%4d)\n", x, y);
0234     }
0235
0236 out:
0237     return IRQ_HANDLED;
0238 }
0239
0240 static int sx8654_reset(struct sx8654 *ts)
0241 {
0242     int err;
0243
0244     if (ts->gpio_reset) {
0245         gpiod_set_value_cansleep(ts->gpio_reset, 1);
0246         udelay(2); /* Tpulse > 1µs */
0247         gpiod_set_value_cansleep(ts->gpio_reset, 0);
0248     } else {
0249         dev_dbg(&ts->client->dev, "NRST unavailable, try softreset\n");
0250         err = i2c_smbus_write_byte_data(ts->client, I2C_REG_SOFTRESET,
0251                         SOFTRESET_VALUE);
0252         if (err)
0253             return err;
0254     }
0255
0256     return 0;
0257 }
0258
0259 static int sx8654_open(struct input_dev *dev)
0260 {
0261     struct sx8654 *sx8654 = input_get_drvdata(dev);
0262     struct i2c_client *client = sx8654->client;
0263     int error;
0264
0265     /* enable pen trigger mode */
0266     error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0,
0267                       RATE_5000CPS | POWDLY_1_1MS);
0268     if (error) {
0269         dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
0270         return error;
0271     }
0272
0273     error = i2c_smbus_write_byte(client, CMD_PENTRG);
0274     if (error) {
0275         dev_err(&client->dev, "writing command CMD_PENTRG failed");
0276         return error;
0277     }
0278
0279     enable_irq(client->irq);
0280
0281     return 0;
0282 }
0283
0284 static void sx8654_close(struct input_dev *dev)
0285 {
0286     struct sx8654 *sx8654 = input_get_drvdata(dev);
0287     struct i2c_client *client = sx8654->client;
0288     int error;
0289
0290     disable_irq(client->irq);
0291
0292     if (!sx8654->data->has_irq_penrelease)
0293         del_timer_sync(&sx8654->timer);
0294
0295     /* enable manual mode mode */
0296     error = i2c_smbus_write_byte(client, sx8654->data->cmd_manual);
0297     if (error) {
0298         dev_err(&client->dev, "writing command CMD_MANUAL failed");
0299         return;
0300     }
0301
0302     error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0, RATE_MANUAL);
0303     if (error) {
0304         dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
0305         return;
0306     }
0307 }
0308
0309 static int sx8654_probe(struct i2c_client *client,
0310             const struct i2c_device_id *id)
0311 {
0312     struct sx8654 *sx8654;
0313     struct input_dev *input;
0314     int error;
0315
0316     if (!i2c_check_functionality(client->adapter,
0317                      I2C_FUNC_SMBUS_READ_WORD_DATA))
0318         return -ENXIO;
0319
0320     sx8654 = devm_kzalloc(&client->dev, sizeof(*sx8654), GFP_KERNEL);
0321     if (!sx8654)
0322         return -ENOMEM;
0323
0324     sx8654->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
0325                              GPIOD_OUT_HIGH);
0326     if (IS_ERR(sx8654->gpio_reset)) {
0327         error = PTR_ERR(sx8654->gpio_reset);
0328         if (error != -EPROBE_DEFER)
0329             dev_err(&client->dev, "unable to get reset-gpio: %d\n",
0330                 error);
0331         return error;
0332     }
0333     dev_dbg(&client->dev, "got GPIO reset pin\n");
0334
0335     sx8654->data = device_get_match_data(&client->dev);
0336     if (!sx8654->data)
0337         sx8654->data = (const struct sx865x_data *)id->driver_data;
0338     if (!sx8654->data) {
0339         dev_err(&client->dev, "invalid or missing device data\n");
0340         return -EINVAL;
0341     }
0342
0343     if (!sx8654->data->has_irq_penrelease) {
0344         dev_dbg(&client->dev, "use timer for penrelease\n");
0345         timer_setup(&sx8654->timer, sx865x_penrelease_timer_handler, 0);
0346         spin_lock_init(&sx8654->lock);
0347     }
0348
0349     input = devm_input_allocate_device(&client->dev);
0350     if (!input)
0351         return -ENOMEM;
0352
0353     input->name = "SX8654 I2C Touchscreen";
0354     input->id.bustype = BUS_I2C;
0355     input->dev.parent = &client->dev;
0356     input->open = sx8654_open;
0357     input->close = sx8654_close;
0358
0359     __set_bit(INPUT_PROP_DIRECT, input->propbit);
0360     input_set_capability(input, EV_KEY, BTN_TOUCH);
0361     input_set_abs_params(input, ABS_X, 0, MAX_12BIT, 0, 0);
0362     input_set_abs_params(input, ABS_Y, 0, MAX_12BIT, 0, 0);
0363
0364     touchscreen_parse_properties(input, false, &sx8654->props);
0365
0366     sx8654->client = client;
0367     sx8654->input = input;
0368
0369     input_set_drvdata(sx8654->input, sx8654);
0370
0371     error = sx8654_reset(sx8654);
0372     if (error) {
0373         dev_err(&client->dev, "reset failed");
0374         return error;
0375     }
0376
0377     error = i2c_smbus_write_byte_data(client, I2C_REG_CHANMASK,
0378                       sx8654->data->chan_mask);
0379     if (error) {
0380         dev_err(&client->dev, "writing to I2C_REG_CHANMASK failed");
0381         return error;
0382     }
0383
0384     if (sx8654->data->has_reg_irqmask) {
0385         error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
0386                           IRQ_PENTOUCH_TOUCHCONVDONE |
0387                             IRQ_PENRELEASE);
0388         if (error) {
0389             dev_err(&client->dev, "writing I2C_REG_IRQMASK failed");
0390             return error;
0391         }
0392     }
0393
0394     error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH1,
0395                       CONDIRQ | RPDNT_100K | FILT_7SA);
0396     if (error) {
0397         dev_err(&client->dev, "writing to I2C_REG_TOUCH1 failed");
0398         return error;
0399     }
0400
0401     error = devm_request_threaded_irq(&client->dev, client->irq,
0402                       NULL, sx8654->data->irqh,
0403                       IRQF_ONESHOT,
0404                       client->name, sx8654);
0405     if (error) {
0406         dev_err(&client->dev,
0407             "Failed to enable IRQ %d, error: %d\n",
0408             client->irq, error);
0409         return error;
0410     }
0411
0412     /* Disable the IRQ, we'll enable it in sx8654_open() */
0413     disable_irq(client->irq);
0414
0415     error = input_register_device(sx8654->input);
0416     if (error)
0417         return error;
0418
0419     return 0;
0420 }
0421
0422 static const struct sx865x_data sx8650_data = {
0423     .cmd_manual     = 0xb0,
0424     .has_irq_penrelease = false,
0425     .has_reg_irqmask    = false,
0426     .chan_mask      = (CONV_X | CONV_Y),
0427     .irqh           = sx8650_irq,
0428 };
0429
0430 static const struct sx865x_data sx8654_data = {
0431     .cmd_manual     = 0xc0,
0432     .has_irq_penrelease = true,
0433     .has_reg_irqmask    = true,
0434     .chan_mask      = (CONV_X | CONV_Y),
0435     .irqh           = sx8654_irq,
0436 };
0437
0438 #ifdef CONFIG_OF
0439 static const struct of_device_id sx8654_of_match[] = {
0440     {
0441         .compatible = "semtech,sx8650",
0442         .data = &sx8650_data,
0443     }, {
0444         .compatible = "semtech,sx8654",
0445         .data = &sx8654_data,
0446     }, {
0447         .compatible = "semtech,sx8655",
0448         .data = &sx8654_data,
0449     }, {
0450         .compatible = "semtech,sx8656",
0451         .data = &sx8654_data,
0452     },
0453     { }
0454 };
0455 MODULE_DEVICE_TABLE(of, sx8654_of_match);
0456 #endif
0457
0458 static const struct i2c_device_id sx8654_id_table[] = {
0459     { .name = "semtech_sx8650", .driver_data = (long)&sx8650_data },
0460     { .name = "semtech_sx8654", .driver_data = (long)&sx8654_data },
0461     { .name = "semtech_sx8655", .driver_data = (long)&sx8654_data },
0462     { .name = "semtech_sx8656", .driver_data = (long)&sx8654_data },
0463     { }
0464 };
0465 MODULE_DEVICE_TABLE(i2c, sx8654_id_table);
0466
0467 static struct i2c_driver sx8654_driver = {
0468     .driver = {
0469         .name = "sx8654",
0470         .of_match_table = of_match_ptr(sx8654_of_match),
0471     },
0472     .id_table = sx8654_id_table,
0473     .probe = sx8654_probe,
0474 };
0475 module_i2c_driver(sx8654_driver);
0476
0477 MODULE_AUTHOR("Sébastien Szymanski <sebastien.szymanski@armadeus.com>");
0478 MODULE_DESCRIPTION("Semtech SX8654 I2C Touchscreen Driver");
0479 MODULE_LICENSE("GPL");