diff mbox series

[v5,2/3] Input: Add Novatek NT36xxx touchscreen driver

Message ID 20201017190152.12780-3-kholk11@gmail.com
State New
Headers show
Series Add Novatek NT36xxx touchscreen driver | expand

Commit Message

AngeloGioacchino Del Regno Oct. 17, 2020, 7:01 p.m. UTC
From: AngeloGioacchino Del Regno <kholk11@gmail.com>

This is a driver for the Novatek in-cell touch controller and
supports various chips from the NT36xxx family, currently
including NT36525, NT36672A, NT36676F, NT36772 and NT36870.

Functionality like wake gestures and firmware flashing is not
included: I am not aware of any of these DrIC+Touch combo
chips not including a non-volatile memory and it should be
highly unlikely to find one, since the touch firmware is
embedded into the DriverIC one, which is obviously necessary
to drive the display unit.

However, the necessary address for the firmware update
procedure was included into the address table in this driver
so, in the event that someone finds the need to implement it
for a reason or another, it will be pretty straightforward to.

This driver is lightly based on the downstream implementation [1].
[1] https://github.com/Rasenkai/caf-tsoft-Novatek-nt36xxx

Signed-off-by: AngeloGioacchino Del Regno <kholk11@gmail.com>
---
 drivers/input/touchscreen/Kconfig   |  12 +
 drivers/input/touchscreen/Makefile  |   1 +
 drivers/input/touchscreen/nt36xxx.c | 815 ++++++++++++++++++++++++++++
 3 files changed, 828 insertions(+)
 create mode 100644 drivers/input/touchscreen/nt36xxx.c

Comments

Andy Shevchenko Oct. 18, 2020, 7:49 p.m. UTC | #1
On Sun, Oct 18, 2020 at 12:40 AM <kholk11@gmail.com> wrote:
>

> From: AngeloGioacchino Del Regno <kholk11@gmail.com>

>

> This is a driver for the Novatek in-cell touch controller and

> supports various chips from the NT36xxx family, currently

> including NT36525, NT36672A, NT36676F, NT36772 and NT36870.

>

> Functionality like wake gestures and firmware flashing is not

> included: I am not aware of any of these DrIC+Touch combo

> chips not including a non-volatile memory and it should be

> highly unlikely to find one, since the touch firmware is

> embedded into the DriverIC one, which is obviously necessary

> to drive the display unit.

>

> However, the necessary address for the firmware update

> procedure was included into the address table in this driver

> so, in the event that someone finds the need to implement it

> for a reason or another, it will be pretty straightforward to.

>

> This driver is lightly based on the downstream implementation [1].

> [1] https://github.com/Rasenkai/caf-tsoft-Novatek-nt36xxx


...

> +#include <linux/delay.h>

> +#include <linux/i2c.h>

> +#include <linux/interrupt.h>

> +#include <linux/module.h>

> +#include <linux/regmap.h>


> +#include <linux/of_gpio.h>


I haven't found evidence you need this header.
But mod_devicetable.h along with gpio/consumer.h seem missed.

> +#include <linux/input/mt.h>

> +#include <linux/input/touchscreen.h>

> +#include <linux/regulator/consumer.h>


...

> +enum nt36xxx_fw_state {

> +       NT36XXX_STATE_INIT = 0xa0,      /* IC reset */

> +       NT36XXX_STATE_REK,              /* ReK baseline */

> +       NT36XXX_STATE_REK_FINISH,       /* Baseline is ready */

> +       NT36XXX_STATE_NORMAL_RUN,       /* Normal run */

> +       NT36XXX_STATE_MAX = 0xaf

> +};


Perhaps kernel doc?

...

> +static int nt36xxx_set_page(struct nt36xxx_i2c *ts, u32 pageaddr)

> +{

> +       u32 data = cpu_to_be32(pageaddr) >> 8;

> +       int ret;

> +

> +       ret = regmap_noinc_write(ts->fw_regmap, NT36XXX_CMD_SET_PAGE,

> +                                &data, sizeof(data));


> +       if (ret == 0)

> +               usleep_range(100, 200);

> +

> +       return ret;


Can you use traditional pattern, i.e.

  if (ret)
    return ret;

  ...
  return 0;

?

> +}

> +

> +static int nt36xxx_sw_reset_idle(struct nt36xxx_i2c *ts)

> +{

> +       int ret;

> +

> +       ret = regmap_write(ts->regmap, ts->hw_client->addr,

> +                          NT36XXX_CMD_SW_RESET);

> +


> +       usleep_range(15000, 16000);


Even in error case? Also, can you explain the value of delay?

> +       return ret;

> +}

> +

> +static int nt36xxx_bootloader_reset(struct nt36xxx_i2c *ts)

> +{

> +       int ret;

> +

> +       ret = regmap_write(ts->regmap, ts->hw_client->addr,

> +                          NT36XXX_CMD_BOOTLOADER_RESET);

> +


> +       msleep(35);


Same as above, esp. taking into account quite a long delay.

> +       return ret;

> +}

> +

> +static int nt36xxx_check_reset_state(struct nt36xxx_i2c *ts,

> +                                    enum nt36xxx_fw_state fw_state)

> +{

> +       u8 buf[2] = { 0 };

> +       int ret, retry = NT36XXX_MAX_FW_RST_RETRY;

> +

> +       do {

> +               ret = regmap_noinc_read(ts->fw_regmap,

> +                                       NT36XXX_EVT_RESET_COMPLETE,

> +                                       buf, sizeof(buf));

> +               if (likely(ret == 0) &&

> +                   (buf[0] >= fw_state) &&

> +                   (buf[0] <= NT36XXX_STATE_MAX)) {

> +                       ret = 0;

> +                       break;

> +               }

> +               usleep_range(10000, 11000);

> +       } while (--retry);

> +

> +       if (!retry) {

> +               dev_err(&ts->hw_client->dev, "Firmware reset failed.\n");

> +               ret = -EBUSY;

> +       }


This sounds like it should be a part of regmap API, such as
regmap_read_poll_timeout().

> +

> +       return ret;

> +}

> +

> +static int nt36xxx_read_pid(struct nt36xxx_i2c *ts)

> +{

> +       u8 buf[2] = { 0 };

> +       int ret = 0;


Redundant assignments.

> +       ret = nt36xxx_set_page(ts, ts->mmap->evtbuf_addr);

> +       if (unlikely(ret < 0))

> +               return ret;

> +

> +       ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_PROJECTID,

> +                               buf, sizeof(buf));

> +       if (unlikely(ret < 0))

> +               return ret;

> +


> +       ts->fw_info.nvt_pid = (buf[1] << 8) + buf[0];


Define buf as __le16 and use le16_to_cpu().

> +

> +       return 0;

> +}

> +

> +static int __nt36xxx_get_fw_info(struct nt36xxx_i2c *ts)

> +{

> +       struct nt36xxx_fw_info *fwi = &ts->fw_info;

> +       u8 buf[11] = { 0 };

> +       int ret = 0;

> +

> +       ret = nt36xxx_set_page(ts, ts->mmap->evtbuf_addr);

> +       if (unlikely(ret < 0))

> +               return ret;

> +

> +       ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_FWINFO,

> +                               buf, sizeof(buf));

> +       if (ret)

> +               return ret;

> +

> +       fwi->fw_ver = buf[0];

> +       fwi->x_num = buf[2];

> +       fwi->y_num = buf[3];

> +       fwi->abs_x_max = (u16)((buf[4] << 8) | buf[5]);

> +       fwi->abs_y_max = (u16)((buf[6] << 8) | buf[7]);


be16_to_cpu() or get_unaligned_be16(), though here it's aligned.

> +       fwi->max_buttons = buf[10];

> +

> +       /* Check fw info integrity and clear x_num, y_num if broken */

> +       if ((buf[0] + buf[1]) != 0xFF) {

> +               dev_err(&ts->hw_client->dev,

> +                       "FW info is broken! fw_ver=0x%02X, ~fw_ver=0x%02X\n",

> +                       buf[0], buf[1]);

> +               fwi->fw_ver = 0;

> +               fwi->x_num = 18;

> +               fwi->y_num = 32;

> +               fwi->abs_x_max = TOUCH_DEFAULT_MAX_WIDTH;

> +               fwi->abs_y_max = TOUCH_DEFAULT_MAX_HEIGHT;

> +               fwi->max_buttons = 0;

> +               return -EINVAL;

> +       }

> +

> +       /* Get Novatek ProjectID */

> +       return nt36xxx_read_pid(ts);

> +}


...

> +static int nvt_stop_crc_reboot(struct nt36xxx_i2c *ts)

> +{

> +       u8 buf[3] = { 0 };

> +       u8 val;

> +       int ret, retry = NT36XXX_MAX_RETRIES;

> +

> +       /* Read dummy buffer to check CRC fail reboot is happening or not */

> +

> +       /* Change I2C index to prevent getting 0xFF, but not 0xFC */

> +       ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CHIP_INFO);

> +       if (ret) {

> +               dev_dbg(&ts->hw_client->dev,

> +                       "CRC reset failed: Cannot select page.\n");

> +               return ret;

> +       }

> +

> +       /* If ChipID command returns 0xFC or 0xFF, the MCU is in CRC reboot */

> +       ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_CHIPID,

> +                               buf, sizeof(buf));

> +       if (ret)

> +               return ret;

> +

> +       if (((buf[0] == 0xFC) && (buf[1] == 0xFC) && (buf[2] == 0xFC)) ||

> +           ((buf[0] == 0xFF) && (buf[1] == 0xFF) && (buf[2] == 0xFF))) {


You may decrese indentation by switching above to be negative conditional.

> +               /* IC is in CRC fail reboot loop, needs to be stopped! */

> +               do {

> +                       /* Special reset-idle sequence for CRC failure */

> +                       ret = regmap_write(ts->regmap, ts->hw_client->addr,

> +                                          NT36XXX_CMD_SW_RESET);


> +                       ret += regmap_write(ts->regmap, ts->hw_client->addr,

> +                                          NT36XXX_CMD_SW_RESET);


It's not good practice to sum error codes.

> +                       if (ret)

> +                               dev_dbg(&ts->hw_client->dev,

> +                                       "SW Reset failed: may not recover\n");

> +                       usleep_range(1000, 1100);

> +

> +                       /* Clear CRC_ERR_FLAG */

> +                       ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CRC);

> +                       if (ret)

> +                               continue;

> +

> +                       val = 0xA5;

> +                       ret = regmap_raw_write(ts->fw_regmap, NT36XXX_EVT_CRC,

> +                                              &val, sizeof(val));

> +                       if (ret)

> +                               continue;

> +

> +                       /* Check CRC_ERR_FLAG */

> +                       ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CRC);

> +                       if (ret)

> +                               continue;

> +

> +                       ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_CRC,

> +                                               &buf, sizeof(buf));

> +                       if (ret)

> +                               continue;

> +

> +                       if (buf[0] == 0xA5)

> +                               break;

> +               } while (--retry);

> +

> +               if (retry == 0) {

> +                       dev_err(&ts->hw_client->dev,

> +                               "CRC reset failed: buf=0x%02x%02x\n",

> +                               buf[0], buf[1]);


%2ph

> +               }

> +       }

> +

> +       return 0;

> +}

> +

> +static int nt36xxx_i2c_chip_version_init(struct nt36xxx_i2c *ts)

> +{

> +       u8 buf[7] = { 0 };

> +       int retry = NT36XXX_MAX_RETRIES;

> +       int sz = sizeof(trim_id_table) / sizeof(struct nt36xxx_trim_table);

> +       int i, list, mapid, ret;

> +

> +       ret = nt36xxx_bootloader_reset(ts);

> +       if (ret < 0) {

> +               dev_err(&ts->hw_client->dev, "Can't reset the nvt IC\n");

> +               return ret;

> +       }

> +

> +       do {

> +               ret = nt36xxx_sw_reset_idle(ts);

> +               if (ret < 0)

> +                       continue;

> +

> +               ret = regmap_write(ts->regmap, ts->hw_client->addr, NT36XXX_CMD_UNLOCK);

> +               if (ret)

> +                       continue;

> +               usleep_range(10000, 11000);

> +

> +               ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CHIP_INFO);

> +               if (ret)

> +                       continue;

> +

> +               memset(buf, 0, ARRAY_SIZE(buf));

> +               ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_CHIPID,

> +                                       buf, sizeof(buf));

> +               if (ret)

> +                       continue;

> +

> +               /* Compare read chip id with trim list */

> +               for (list = 0; list < sz; list++) {

> +                       /* Compare each not masked byte */

> +                       for (i = 0; i < NT36XXX_ID_LEN_MAX; i++) {

> +                               if (trim_id_table[list].mask[i] &&

> +                                   buf[i] != trim_id_table[list].id[i])

> +                                       break;

> +                       }

> +

> +                       if (i == NT36XXX_ID_LEN_MAX) {

> +                               mapid = trim_id_table[list].mapid;

> +                               ts->mmap = &nt36xxx_memory_maps[mapid];

> +                               return 0;

> +                       }

> +

> +                       ts->mmap = NULL;

> +                       ret = -ENOENT;

> +               }

> +

> +               /* Stop CRC check to prevent IC auto reboot */

> +               if (((buf[1] == 0xFC) && (buf[2] == 0xFC) &&

> +                    (buf[3] == 0xFC)) ||

> +                   ((buf[1] == 0xFF) && (buf[2] == 0xFF) &&

> +                    (buf[3] == 0xFF))) {


You already have the same code above. Perhaps helper is good to have for this.

> +                       ret = nvt_stop_crc_reboot(ts);

> +                       if (ret < 0)

> +                               continue;

> +               }

> +

> +               usleep_range(10000, 11000);

> +       } while (--retry);

> +

> +       return ret;

> +}

> +

> +static const struct regmap_config nt36xxx_i2c_regmap_hw_config = {

> +       .name = "nt36xxx_i2c_hw",

> +       .reg_bits = 8,

> +       .val_bits = 8,

> +       .cache_type = REGCACHE_NONE,

> +};

> +

> +static const struct regmap_config nt36xxx_i2c_regmap_fw_config = {

> +       .name = "nt36xxx_i2c_fw",

> +       .reg_bits = 8,

> +       .val_bits = 8,

> +       .cache_type = REGCACHE_NONE,

> +};

> +

> +static void nt36xxx_disable_regulators(void *data)

> +{

> +       struct nt36xxx_i2c *ts = data;

> +

> +       regulator_bulk_disable(NT36XXX_NUM_SUPPLIES, ts->supplies);

> +}

> +

> +static int nt36xxx_i2c_probe(struct i2c_client *hw_client,

> +                            const struct i2c_device_id *id)

> +{

> +       struct nt36xxx_i2c *ts;

> +       struct input_dev *input;

> +       int ret;

> +

> +       if (!i2c_check_functionality(hw_client->adapter, I2C_FUNC_I2C)) {

> +               dev_err(&hw_client->dev, "i2c_check_functionality error\n");

> +               return -EIO;

> +       }

> +

> +       if (!hw_client->irq) {

> +               dev_err(&hw_client->dev, "No irq specified\n");

> +               return -EINVAL;

> +       }

> +

> +       ts = devm_kzalloc(&hw_client->dev, sizeof(struct nt36xxx_i2c), GFP_KERNEL);

> +       if (!ts)

> +               return -ENOMEM;

> +

> +       ts->supplies = devm_kcalloc(&hw_client->dev,

> +                                   NT36XXX_NUM_SUPPLIES,

> +                                   sizeof(struct regulator_bulk_data),

> +                                   GFP_KERNEL);

> +       if (!ts->supplies)

> +               return -ENOMEM;

> +

> +       input = devm_input_allocate_device(&hw_client->dev);

> +       if (!input)

> +               return -ENOMEM;

> +

> +       ts->fw_client = i2c_new_dummy_device(hw_client->adapter,

> +                                            NT36XXX_FW_ADDR);

> +       if (IS_ERR(ts->fw_client)) {

> +               dev_err(&hw_client->dev, "Cannot add FW I2C device\n");

> +               return PTR_ERR(ts->fw_client);

> +       }

> +

> +       ts->hw_client = hw_client;

> +       ts->input = input;

> +       i2c_set_clientdata(ts->hw_client, ts);

> +       i2c_set_clientdata(ts->fw_client, ts);

> +

> +       ts->reset_gpio = devm_gpiod_get_optional(&hw_client->dev, "reset",

> +                                                GPIOD_OUT_HIGH);

> +       if (IS_ERR(ts->reset_gpio))

> +               return PTR_ERR(ts->reset_gpio);


> +       if (ts->reset_gpio)


Redundant. If you mark GPIO as optional all those checks should not be here.

> +               gpiod_set_consumer_name(ts->reset_gpio, "nt36xxx reset");

> +

> +       /* These supplies are optional */

> +       ts->supplies[0].supply = "vdd";

> +       ts->supplies[1].supply = "vio";

> +       ret = devm_regulator_bulk_get(&hw_client->dev,

> +                                     NT36XXX_NUM_SUPPLIES,

> +                                     ts->supplies);

> +       if (ret != 0) {


if (ret)

> +               if (ret != -EPROBE_DEFER)

> +                       dev_err(&hw_client->dev,

> +                               "Cannot get supplies: %d\n", ret);

> +               return ret;


I think there is no return dev_err_probe() here b/c Dmitry is against it?

> +       }

> +

> +       ts->regmap = devm_regmap_init_i2c(ts->hw_client,

> +                                         &nt36xxx_i2c_regmap_hw_config);

> +       if (IS_ERR(ts->regmap)) {

> +               dev_err(&hw_client->dev, "regmap (hw-addr) init failed\n");

> +               return PTR_ERR(ts->regmap);

> +       }

> +

> +       ts->fw_regmap = devm_regmap_init_i2c(ts->fw_client,

> +                                            &nt36xxx_i2c_regmap_fw_config);

> +       if (IS_ERR(ts->fw_regmap)) {

> +               dev_err(&hw_client->dev, "regmap (fw-addr) init failed\n");

> +               return PTR_ERR(ts->fw_regmap);

> +       }

> +

> +       ret = regulator_bulk_enable(NT36XXX_NUM_SUPPLIES, ts->supplies);

> +       if (ret)

> +               return ret;


> +       usleep_range(10000, 11000);


Why?

> +       ret = devm_add_action_or_reset(&hw_client->dev,

> +                                      nt36xxx_disable_regulators, ts);

> +       if (ret)

> +               return ret;

> +

> +       mutex_init(&ts->lock);

> +

> +       /* Set memory maps for the specific chip version */

> +       ret = nt36xxx_i2c_chip_version_init(ts);

> +       if (ret) {

> +               dev_err(&hw_client->dev, "Failed to check chip version\n");

> +               return ret;

> +       }

> +

> +       /* Reset the MCU */

> +       ret = nt36xxx_bootloader_reset(ts);


> +       if (unlikely(ret < 0))


All these unlikely() calls are unlikely needed. Please, drop them for
the sake of readability.

> +               return ret;

> +

> +       /* Check and eventually wait until the MCU goes in reset state */

> +       ret = nt36xxx_check_reset_state(ts, NT36XXX_STATE_INIT);

> +       if (unlikely(ret < 0))

> +               return ret;

> +

> +       /* Get informations from the TS firmware */

> +       ret = nt36xxx_get_fw_info(ts);

> +       if (unlikely(ret < 0))

> +               return ret;

> +

> +       input->phys = devm_kasprintf(&hw_client->dev, GFP_KERNEL,

> +                                    "%s/input0", dev_name(&hw_client->dev));

> +

> +       input->name = "Novatek NT36XXX Touchscreen";

> +       input->id.bustype = BUS_I2C;

> +       input->dev.parent = &hw_client->dev;

> +

> +       __set_bit(EV_KEY, input->evbit);

> +       __set_bit(EV_ABS, input->evbit);

> +       input_set_capability(input, EV_KEY, BTN_TOUCH);

> +

> +       ret = input_mt_init_slots(input, TOUCH_MAX_FINGER_NUM,

> +                                 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);

> +       if (ret) {

> +               dev_err(&hw_client->dev, "Cannot init MT slots (%d)\n", ret);

> +               return ret;

> +       }

> +

> +       input_set_abs_params(input, ABS_MT_PRESSURE, 0,

> +                            TOUCH_MAX_PRESSURE, 0, 0);

> +       input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);

> +

> +       input_set_abs_params(input, ABS_MT_POSITION_X, 0,

> +                            ts->fw_info.abs_x_max - 1, 0, 0);

> +       input_set_abs_params(input, ABS_MT_POSITION_Y, 0,

> +                            ts->fw_info.abs_y_max - 1, 0, 0);

> +

> +       /* Override the firmware defaults, if needed */

> +       touchscreen_parse_properties(input, true, &ts->prop);

> +

> +       input_set_drvdata(input, ts);

> +

> +       ret = input_register_device(ts->input);

> +       if (ret) {

> +               dev_err(&hw_client->dev, "Failed to register input device: %d\n",

> +                       ret);

> +               return ret;

> +       }

> +

> +       ret = devm_request_threaded_irq(&hw_client->dev, hw_client->irq, NULL,

> +                                       nt36xxx_i2c_irq_handler, IRQF_ONESHOT,

> +                                       hw_client->name, ts);

> +       if (ret) {

> +               dev_err(&hw_client->dev, "request irq failed: %d\n", ret);


> +               return ret;

> +       }

> +

> +       return 0;


return ret; ?

> +}

> +

> +static int __maybe_unused nt36xxx_i2c_suspend(struct device *dev)

> +{

> +       struct nt36xxx_i2c *ts = i2c_get_clientdata(to_i2c_client(dev));

> +       int ret;

> +

> +       disable_irq(ts->hw_client->irq);

> +

> +       ret = regmap_write(ts->fw_regmap, NT36XXX_EVT_HOST_CMD,

> +                          NT36XXX_CMD_ENTER_SLEEP);

> +       if (unlikely(ret)) {

> +               dev_err(&ts->hw_client->dev, "Cannot enter suspend!!\n");

> +               return ret;

> +       }


> +       if (ts->reset_gpio)


Redundant.

> +               gpiod_set_value(ts->reset_gpio, 1);

> +

> +       return 0;

> +}

> +

> +static int __maybe_unused nt36xxx_i2c_resume(struct device *dev)

> +{

> +       struct nt36xxx_i2c *ts = i2c_get_clientdata(to_i2c_client(dev));

> +       int ret;

> +

> +       mutex_lock(&ts->lock);


> +       if (ts->reset_gpio)


Redundant.

> +               gpiod_set_value(ts->reset_gpio, 0);


> +       /* Reboot the MCU (also recalibrates the TS) */

> +       ret = nt36xxx_bootloader_reset(ts);

> +       if (ret < 0)

> +               goto end;

> +

> +       ret = nt36xxx_check_reset_state(ts, NT36XXX_STATE_REK);

> +       if (ret < 0)

> +               goto end;

> +

> +       enable_irq(ts->hw_client->irq);

> +end:

> +       mutex_unlock(&ts->lock);

> +       return ret;

> +}

> +

> +static SIMPLE_DEV_PM_OPS(nt36xxx_i2c_pm,

> +                        nt36xxx_i2c_suspend, nt36xxx_i2c_resume);

> +

> +#ifdef CONFIG_OF

> +static const struct of_device_id nt36xxx_of_match[] = {

> +       { .compatible = "novatek,nt36525" },

> +       { }

> +};

> +MODULE_DEVICE_TABLE(of, nt36xxx_of_match);

> +#endif

> +

> +static const struct i2c_device_id nt36xxx_i2c_ts_id[] = {

> +       { "NVT-ts", 0 },

> +       { }

> +};

> +MODULE_DEVICE_TABLE(i2c, nt36xxx_i2c_ts_id);

> +

> +static struct i2c_driver nt36xxx_i2c_ts_driver = {

> +       .driver = {

> +               .name   = "nt36xxx_ts",

> +               .pm     = &nt36xxx_i2c_pm,


> +               .of_match_table = of_match_ptr(nt36xxx_of_match),


You may do a good job by dropping these of_match_ptr() along with ugly
ifdeffery above. It will allow to use it on ACPI-enabled platforms.

> +       },



--
With Best Regards,
Andy Shevchenko
Dmitry Torokhov Oct. 21, 2020, 9:16 p.m. UTC | #2
Hi AngeloGioacchino,

[obviously not a complete review, but wanted to call out regmap concern]

On Sat, Oct 17, 2020 at 09:01:51PM +0200, kholk11@gmail.com wrote:
> +static int nt36xxx_read_pid(struct nt36xxx_i2c *ts)
> +{
> +	u8 buf[2] = { 0 };

	__be16 pid;

> +	int ret = 0;
> +
> +	ret = nt36xxx_set_page(ts, ts->mmap->evtbuf_addr);
> +	if (unlikely(ret < 0))
> +		return ret;

regmap is supposed to help with the paged registers, that is why I
recommended using it.

> +
> +	ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_PROJECTID,
> +				buf, sizeof(buf));
> +	if (unlikely(ret < 0))
> +		return ret;
> +
> +	ts->fw_info.nvt_pid = (buf[1] << 8) + buf[0];

	ts->fw_info.nvt_pid = be16_to_cpu(pid);

Thanks.
diff mbox series

Patch

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 35c867b2d9a7..6d118b967021 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -605,6 +605,18 @@  config TOUCHSCREEN_MTOUCH
 	  To compile this driver as a module, choose M here: the
 	  module will be called mtouch.
 
+config TOUCHSCREEN_NT36XXX
+	tristate "Novatek NT36XXX In-Cell I2C touchscreen controller"
+	depends on I2C
+	help
+	  Say Y here if you have a Novatek NT36xxx series In-Cell
+	  touchscreen connected to your system over I2C.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called nt36xxx.
+
 config TOUCHSCREEN_IMX6UL_TSC
 	tristate "Freescale i.MX6UL touchscreen controller"
 	depends on (OF && GPIOLIB) || COMPILE_TEST
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 30d1e1b42492..424a555e03d5 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -61,6 +61,7 @@  obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MMS114)	+= mms114.o
 obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)		+= mk712.o
+obj-$(CONFIG_TOUCHSCREEN_NT36XXX)	+= nt36xxx.o
 obj-$(CONFIG_TOUCHSCREEN_HP600)		+= hp680_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jornada720_ts.o
 obj-$(CONFIG_TOUCHSCREEN_IPAQ_MICRO)	+= ipaq-micro-ts.o
diff --git a/drivers/input/touchscreen/nt36xxx.c b/drivers/input/touchscreen/nt36xxx.c
new file mode 100644
index 000000000000..893ed7b6faf6
--- /dev/null
+++ b/drivers/input/touchscreen/nt36xxx.c
@@ -0,0 +1,815 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2010 - 2017 Novatek, Inc.
+ * Copyright (C) 2020 AngeloGioacchino Del Regno <kholk11@gmail.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/of_gpio.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/regulator/consumer.h>
+
+/* FW Param address */
+#define NT36XXX_FW_ADDR 0x01
+
+/* Number of bytes for chip identification */
+#define NT36XXX_ID_LEN_MAX	6
+
+/* Touch info */
+#define TOUCH_DEFAULT_MAX_WIDTH  1080
+#define TOUCH_DEFAULT_MAX_HEIGHT 2246
+#define TOUCH_MAX_FINGER_NUM	 10
+#define TOUCH_MAX_PRESSURE	 1000
+
+/* Point data length */
+#define POINT_DATA_LEN		65
+
+/* Global pages */
+#define NT36XXX_PAGE_CHIP_INFO	0x0001f64e
+#define NT36XXX_PAGE_CRC	0x0003f135
+
+/* Misc */
+#define NT36XXX_NUM_SUPPLIES	 2
+#define NT36XXX_MAX_RETRIES	 5
+#define NT36XXX_MAX_FW_RST_RETRY 50
+
+struct nt36xxx_abs_object {
+	u16 x;
+	u16 y;
+	u16 z;
+	u8 tm;
+};
+
+struct nt36xxx_fw_info {
+	u8 fw_ver;
+	u8 x_num;
+	u8 y_num;
+	u8 max_buttons;
+	u16 abs_x_max;
+	u16 abs_y_max;
+	u16 nvt_pid;
+};
+
+struct nt36xxx_mem_map {
+	u32 evtbuf_addr;
+	u32 pipe0_addr;
+	u32 pipe1_addr;
+	u32 flash_csum_addr;
+	u32 flash_data_addr;
+};
+
+struct nt36xxx_i2c {
+	struct i2c_client *hw_client;
+	struct i2c_client *fw_client;
+	struct regmap *regmap;
+	struct regmap *fw_regmap;
+	struct input_dev *input;
+	struct regulator_bulk_data *supplies;
+	struct gpio_desc *reset_gpio;
+
+	struct mutex lock;
+
+	struct touchscreen_properties prop;
+	struct nt36xxx_fw_info fw_info;
+	struct nt36xxx_abs_object abs_obj;
+
+	const struct nt36xxx_mem_map *mmap;
+};
+
+enum nt36xxx_chips {
+	NT36525_IC = 0,
+	NT36672A_IC,
+	NT36676F_IC,
+	NT36772_IC,
+	NT36870_IC,
+	NTMAX_IC,
+};
+
+struct nt36xxx_trim_table {
+	u8 id[NT36XXX_ID_LEN_MAX];
+	u8 mask[NT36XXX_ID_LEN_MAX];
+	enum nt36xxx_chips mapid;
+};
+
+enum nt36xxx_cmds {
+	NT36XXX_CMD_ENTER_SLEEP = 0x11,
+	NT36XXX_CMD_ENTER_WKUP_GESTURE = 0x13,
+	NT36XXX_CMD_UNLOCK = 0x35,
+	NT36XXX_CMD_BOOTLOADER_RESET = 0x69,
+	NT36XXX_CMD_SW_RESET = 0xa5,
+	NT36XXX_CMD_SET_PAGE = 0xff,
+};
+
+enum nt36xxx_fw_state {
+	NT36XXX_STATE_INIT = 0xa0,	/* IC reset */
+	NT36XXX_STATE_REK,		/* ReK baseline */
+	NT36XXX_STATE_REK_FINISH,	/* Baseline is ready */
+	NT36XXX_STATE_NORMAL_RUN,	/* Normal run */
+	NT36XXX_STATE_MAX = 0xaf
+};
+
+enum nt36xxx_i2c_events {
+	NT36XXX_EVT_REPORT = 0x00,
+	NT36XXX_EVT_CRC = 0x35,
+	NT36XXX_EVT_CHIPID = 0x4e,
+	NT36XXX_EVT_HOST_CMD = 0x50,
+	NT36XXX_EVT_HS_OR_SUBCMD = 0x51,   /* Handshake or subcommand byte */
+	NT36XXX_EVT_RESET_COMPLETE = 0x60,
+	NT36XXX_EVT_FWINFO = 0x78,
+	NT36XXX_EVT_PROJECTID = 0x9a,
+};
+
+static const struct nt36xxx_mem_map nt36xxx_memory_maps[] = {
+	[NT36525_IC]  = { 0x11a00, 0x10000, 0x12000, 0x14000, 0x14002 },
+	[NT36672A_IC] = { 0x21c00, 0x20000, 0x23000, 0x24000, 0x24002 },
+	[NT36676F_IC] = { 0x11a00, 0x10000, 0x12000, 0x14000, 0x14002 },
+	[NT36772_IC]  = { 0x11e00, 0x10000, 0x12000, 0x14000, 0x14002 },
+	[NT36870_IC]  = { 0x25000, 0x20000, 0x23000, 0x24000, 0x24002 },
+};
+
+static const struct nt36xxx_trim_table trim_id_table[] = {
+	{
+	 .id = { 0x0A, 0xFF, 0xFF, 0x72, 0x66, 0x03 },
+	 .mask = { 1, 0, 0, 1, 1, 1 },
+	 .mapid = NT36672A_IC,
+	},
+	{
+	 .id = { 0x55, 0x00, 0xFF, 0x00, 0x00, 0x00 },
+	 .mask = { 1, 1, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0x55, 0x72, 0xFF, 0x00, 0x00, 0x00 },
+	 .mask = { 1, 1, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xAA, 0x00, 0xFF, 0x00, 0x00, 0x00 },
+	 .mask = { 1, 1, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xAA, 0x72, 0xFF, 0x00, 0x00, 0x00 },
+	 .mask = { 1, 1, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xFF, 0xFF, 0xFF, 0x72, 0x67, 0x03 },
+	 .mask = { 0, 0, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xFF, 0xFF, 0xFF, 0x70, 0x66, 0x03 },
+	 .mask = { 0, 0, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xFF, 0xFF, 0xFF, 0x70, 0x67, 0x03 },
+	 .mask = { 0, 0, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xFF, 0xFF, 0xFF, 0x72, 0x66, 0x03 },
+	 .mask = { 0, 0, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xFF, 0xFF, 0xFF, 0x25, 0x65, 0x03 },
+	 .mask = { 0, 0, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xFF, 0xFF, 0xFF, 0x70, 0x68, 0x03 },
+	 .mask = { 0, 0, 0, 1, 1, 1 },
+	 .mapid = NT36772_IC,
+	},
+	{
+	 .id = { 0xFF, 0xFF, 0xFF, 0x76, 0x66, 0x03 },
+	 .mask = { 0, 0, 0, 1, 1, 1 },
+	 .mapid = NT36676F_IC,
+	},
+};
+
+static int nt36xxx_set_page(struct nt36xxx_i2c *ts, u32 pageaddr)
+{
+	u32 data = cpu_to_be32(pageaddr) >> 8;
+	int ret;
+
+	ret = regmap_noinc_write(ts->fw_regmap, NT36XXX_CMD_SET_PAGE,
+				 &data, sizeof(data));
+	if (ret == 0)
+		usleep_range(100, 200);
+
+	return ret;
+}
+
+static int nt36xxx_sw_reset_idle(struct nt36xxx_i2c *ts)
+{
+	int ret;
+
+	ret = regmap_write(ts->regmap, ts->hw_client->addr,
+			   NT36XXX_CMD_SW_RESET);
+
+	usleep_range(15000, 16000);
+	return ret;
+}
+
+static int nt36xxx_bootloader_reset(struct nt36xxx_i2c *ts)
+{
+	int ret;
+
+	ret = regmap_write(ts->regmap, ts->hw_client->addr,
+			   NT36XXX_CMD_BOOTLOADER_RESET);
+
+	msleep(35);
+	return ret;
+}
+
+static int nt36xxx_check_reset_state(struct nt36xxx_i2c *ts,
+				     enum nt36xxx_fw_state fw_state)
+{
+	u8 buf[2] = { 0 };
+	int ret, retry = NT36XXX_MAX_FW_RST_RETRY;
+
+	do {
+		ret = regmap_noinc_read(ts->fw_regmap,
+					NT36XXX_EVT_RESET_COMPLETE,
+					buf, sizeof(buf));
+		if (likely(ret == 0) &&
+		    (buf[0] >= fw_state) &&
+		    (buf[0] <= NT36XXX_STATE_MAX)) {
+			ret = 0;
+			break;
+		}
+		usleep_range(10000, 11000);
+	} while (--retry);
+
+	if (!retry) {
+		dev_err(&ts->hw_client->dev, "Firmware reset failed.\n");
+		ret = -EBUSY;
+	}
+
+	return ret;
+}
+
+static int nt36xxx_read_pid(struct nt36xxx_i2c *ts)
+{
+	u8 buf[2] = { 0 };
+	int ret = 0;
+
+	ret = nt36xxx_set_page(ts, ts->mmap->evtbuf_addr);
+	if (unlikely(ret < 0))
+		return ret;
+
+	ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_PROJECTID,
+				buf, sizeof(buf));
+	if (unlikely(ret < 0))
+		return ret;
+
+	ts->fw_info.nvt_pid = (buf[1] << 8) + buf[0];
+
+	return 0;
+}
+
+static int __nt36xxx_get_fw_info(struct nt36xxx_i2c *ts)
+{
+	struct nt36xxx_fw_info *fwi = &ts->fw_info;
+	u8 buf[11] = { 0 };
+	int ret = 0;
+
+	ret = nt36xxx_set_page(ts, ts->mmap->evtbuf_addr);
+	if (unlikely(ret < 0))
+		return ret;
+
+	ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_FWINFO,
+				buf, sizeof(buf));
+	if (ret)
+		return ret;
+
+	fwi->fw_ver = buf[0];
+	fwi->x_num = buf[2];
+	fwi->y_num = buf[3];
+	fwi->abs_x_max = (u16)((buf[4] << 8) | buf[5]);
+	fwi->abs_y_max = (u16)((buf[6] << 8) | buf[7]);
+	fwi->max_buttons = buf[10];
+
+	/* Check fw info integrity and clear x_num, y_num if broken */
+	if ((buf[0] + buf[1]) != 0xFF) {
+		dev_err(&ts->hw_client->dev,
+			"FW info is broken! fw_ver=0x%02X, ~fw_ver=0x%02X\n",
+			buf[0], buf[1]);
+		fwi->fw_ver = 0;
+		fwi->x_num = 18;
+		fwi->y_num = 32;
+		fwi->abs_x_max = TOUCH_DEFAULT_MAX_WIDTH;
+		fwi->abs_y_max = TOUCH_DEFAULT_MAX_HEIGHT;
+		fwi->max_buttons = 0;
+		return -EINVAL;
+	}
+
+	/* Get Novatek ProjectID */
+	return nt36xxx_read_pid(ts);
+}
+
+static int nt36xxx_get_fw_info(struct nt36xxx_i2c *ts)
+{
+	struct nt36xxx_fw_info *fwi = &ts->fw_info;
+	int i, ret = 0;
+
+	for (i = 0; i < NT36XXX_MAX_RETRIES; i++) {
+		ret = __nt36xxx_get_fw_info(ts);
+		if (ret == 0)
+			break;
+	}
+
+	dev_dbg(&ts->hw_client->dev,
+		"FW Info: PID=0x%x, ver=0x%x res=%ux%u max=%ux%u buttons=%u",
+		fwi->nvt_pid, fwi->fw_ver, fwi->x_num, fwi->y_num,
+		fwi->abs_x_max, fwi->abs_y_max, fwi->max_buttons);
+
+	return ret;
+}
+
+static void nt36xxx_report(struct nt36xxx_i2c *ts)
+{
+	struct nt36xxx_abs_object *obj = &ts->abs_obj;
+	struct input_dev *input = ts->input;
+	u8 input_id = 0;
+	u8 point[POINT_DATA_LEN + 1] = { 0 };
+	unsigned int ppos = 0;
+	int i, ret, finger_cnt = 0;
+
+	mutex_lock(&ts->lock);
+
+	ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_REPORT,
+				point, sizeof(point));
+	if (unlikely(ret < 0)) {
+		dev_err(&ts->hw_client->dev,
+			"Cannot read touch point data: %d\n", ret);
+		goto xfer_error;
+	}
+
+	for (i = 0; i < TOUCH_MAX_FINGER_NUM; i++) {
+		ppos = 6 * i;
+		input_id = point[ppos + 0] >> 3;
+		if ((input_id == 0) || (input_id > TOUCH_MAX_FINGER_NUM))
+			continue;
+
+		if (((point[ppos] & 0x07) == 0x01) ||
+		    ((point[ppos] & 0x07) == 0x02)) {
+			obj->x = (point[ppos + 1] << 4) +
+				 (point[ppos + 3] >> 4);
+			obj->y = (point[ppos + 2] << 4) +
+				 (point[ppos + 3] & 0xf);
+			if ((obj->x > ts->prop.max_x) ||
+			    (obj->y > ts->prop.max_y))
+				continue;
+
+			obj->tm = point[ppos + 4];
+			if (obj->tm == 0)
+				obj->tm = 1;
+
+			obj->z = point[ppos + 5];
+			if (i < 2) {
+				obj->z += point[i + 63] << 8;
+				if (obj->z > TOUCH_MAX_PRESSURE)
+					obj->z = TOUCH_MAX_PRESSURE;
+			}
+
+			if (obj->z == 0)
+				obj->z = 1;
+
+			input_mt_slot(input, input_id - 1);
+			input_mt_report_slot_state(input,
+						   MT_TOOL_FINGER, true);
+			touchscreen_report_pos(input, &ts->prop, obj->x,
+					       obj->y, true);
+
+			input_report_abs(input, ABS_MT_TOUCH_MAJOR, obj->tm);
+			input_report_abs(input, ABS_MT_PRESSURE, obj->z);
+
+			finger_cnt++;
+		}
+	}
+	input_mt_sync_frame(input);
+	input_sync(input);
+
+xfer_error:
+	enable_irq(ts->hw_client->irq);
+
+	mutex_unlock(&ts->lock);
+}
+
+static irqreturn_t nt36xxx_i2c_irq_handler(int irq, void *dev_id)
+{
+	struct nt36xxx_i2c *ts = dev_id;
+
+	disable_irq_nosync(ts->hw_client->irq);
+	nt36xxx_report(ts);
+
+	return IRQ_HANDLED;
+}
+
+static int nvt_stop_crc_reboot(struct nt36xxx_i2c *ts)
+{
+	u8 buf[3] = { 0 };
+	u8 val;
+	int ret, retry = NT36XXX_MAX_RETRIES;
+
+	/* Read dummy buffer to check CRC fail reboot is happening or not */
+
+	/* Change I2C index to prevent getting 0xFF, but not 0xFC */
+	ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CHIP_INFO);
+	if (ret) {
+		dev_dbg(&ts->hw_client->dev,
+			"CRC reset failed: Cannot select page.\n");
+		return ret;
+	}
+
+	/* If ChipID command returns 0xFC or 0xFF, the MCU is in CRC reboot */
+	ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_CHIPID,
+				buf, sizeof(buf));
+	if (ret)
+		return ret;
+
+	if (((buf[0] == 0xFC) && (buf[1] == 0xFC) && (buf[2] == 0xFC)) ||
+	    ((buf[0] == 0xFF) && (buf[1] == 0xFF) && (buf[2] == 0xFF))) {
+		/* IC is in CRC fail reboot loop, needs to be stopped! */
+		do {
+			/* Special reset-idle sequence for CRC failure */
+			ret = regmap_write(ts->regmap, ts->hw_client->addr,
+					   NT36XXX_CMD_SW_RESET);
+			ret += regmap_write(ts->regmap, ts->hw_client->addr,
+					   NT36XXX_CMD_SW_RESET);
+			if (ret)
+				dev_dbg(&ts->hw_client->dev,
+					"SW Reset failed: may not recover\n");
+			usleep_range(1000, 1100);
+
+			/* Clear CRC_ERR_FLAG */
+			ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CRC);
+			if (ret)
+				continue;
+
+			val = 0xA5;
+			ret = regmap_raw_write(ts->fw_regmap, NT36XXX_EVT_CRC,
+					       &val, sizeof(val));
+			if (ret)
+				continue;
+
+			/* Check CRC_ERR_FLAG */
+			ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CRC);
+			if (ret)
+				continue;
+
+			ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_CRC,
+						&buf, sizeof(buf));
+			if (ret)
+				continue;
+
+			if (buf[0] == 0xA5)
+				break;
+		} while (--retry);
+
+		if (retry == 0) {
+			dev_err(&ts->hw_client->dev,
+				"CRC reset failed: buf=0x%02x%02x\n",
+				buf[0], buf[1]);
+		}
+	}
+
+	return 0;
+}
+
+static int nt36xxx_i2c_chip_version_init(struct nt36xxx_i2c *ts)
+{
+	u8 buf[7] = { 0 };
+	int retry = NT36XXX_MAX_RETRIES;
+	int sz = sizeof(trim_id_table) / sizeof(struct nt36xxx_trim_table);
+	int i, list, mapid, ret;
+
+	ret = nt36xxx_bootloader_reset(ts);
+	if (ret < 0) {
+		dev_err(&ts->hw_client->dev, "Can't reset the nvt IC\n");
+		return ret;
+	}
+
+	do {
+		ret = nt36xxx_sw_reset_idle(ts);
+		if (ret < 0)
+			continue;
+
+		ret = regmap_write(ts->regmap, ts->hw_client->addr, NT36XXX_CMD_UNLOCK);
+		if (ret)
+			continue;
+		usleep_range(10000, 11000);
+
+		ret = nt36xxx_set_page(ts, NT36XXX_PAGE_CHIP_INFO);
+		if (ret)
+			continue;
+
+		memset(buf, 0, ARRAY_SIZE(buf));
+		ret = regmap_noinc_read(ts->fw_regmap, NT36XXX_EVT_CHIPID,
+					buf, sizeof(buf));
+		if (ret)
+			continue;
+
+		/* Compare read chip id with trim list */
+		for (list = 0; list < sz; list++) {
+			/* Compare each not masked byte */
+			for (i = 0; i < NT36XXX_ID_LEN_MAX; i++) {
+				if (trim_id_table[list].mask[i] &&
+				    buf[i] != trim_id_table[list].id[i])
+					break;
+			}
+
+			if (i == NT36XXX_ID_LEN_MAX) {
+				mapid = trim_id_table[list].mapid;
+				ts->mmap = &nt36xxx_memory_maps[mapid];
+				return 0;
+			}
+
+			ts->mmap = NULL;
+			ret = -ENOENT;
+		}
+
+		/* Stop CRC check to prevent IC auto reboot */
+		if (((buf[1] == 0xFC) && (buf[2] == 0xFC) &&
+		     (buf[3] == 0xFC)) ||
+		    ((buf[1] == 0xFF) && (buf[2] == 0xFF) &&
+		     (buf[3] == 0xFF))) {
+			ret = nvt_stop_crc_reboot(ts);
+			if (ret < 0)
+				continue;
+		}
+
+		usleep_range(10000, 11000);
+	} while (--retry);
+
+	return ret;
+}
+
+static const struct regmap_config nt36xxx_i2c_regmap_hw_config = {
+	.name = "nt36xxx_i2c_hw",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_NONE,
+};
+
+static const struct regmap_config nt36xxx_i2c_regmap_fw_config = {
+	.name = "nt36xxx_i2c_fw",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_NONE,
+};
+
+static void nt36xxx_disable_regulators(void *data)
+{
+	struct nt36xxx_i2c *ts = data;
+
+	regulator_bulk_disable(NT36XXX_NUM_SUPPLIES, ts->supplies);
+}
+
+static int nt36xxx_i2c_probe(struct i2c_client *hw_client,
+			     const struct i2c_device_id *id)
+{
+	struct nt36xxx_i2c *ts;
+	struct input_dev *input;
+	int ret;
+
+	if (!i2c_check_functionality(hw_client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&hw_client->dev, "i2c_check_functionality error\n");
+		return -EIO;
+	}
+
+	if (!hw_client->irq) {
+		dev_err(&hw_client->dev, "No irq specified\n");
+		return -EINVAL;
+	}
+
+	ts = devm_kzalloc(&hw_client->dev, sizeof(struct nt36xxx_i2c), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	ts->supplies = devm_kcalloc(&hw_client->dev,
+				    NT36XXX_NUM_SUPPLIES,
+				    sizeof(struct regulator_bulk_data),
+				    GFP_KERNEL);
+	if (!ts->supplies)
+		return -ENOMEM;
+
+	input = devm_input_allocate_device(&hw_client->dev);
+	if (!input)
+		return -ENOMEM;
+
+	ts->fw_client = i2c_new_dummy_device(hw_client->adapter,
+					     NT36XXX_FW_ADDR);
+	if (IS_ERR(ts->fw_client)) {
+		dev_err(&hw_client->dev, "Cannot add FW I2C device\n");
+		return PTR_ERR(ts->fw_client);
+	}
+
+	ts->hw_client = hw_client;
+	ts->input = input;
+	i2c_set_clientdata(ts->hw_client, ts);
+	i2c_set_clientdata(ts->fw_client, ts);
+
+	ts->reset_gpio = devm_gpiod_get_optional(&hw_client->dev, "reset",
+						 GPIOD_OUT_HIGH);
+	if (IS_ERR(ts->reset_gpio))
+		return PTR_ERR(ts->reset_gpio);
+	if (ts->reset_gpio)
+		gpiod_set_consumer_name(ts->reset_gpio, "nt36xxx reset");
+
+	/* These supplies are optional */
+	ts->supplies[0].supply = "vdd";
+	ts->supplies[1].supply = "vio";
+	ret = devm_regulator_bulk_get(&hw_client->dev,
+				      NT36XXX_NUM_SUPPLIES,
+				      ts->supplies);
+	if (ret != 0) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(&hw_client->dev,
+				"Cannot get supplies: %d\n", ret);
+		return ret;
+	}
+
+	ts->regmap = devm_regmap_init_i2c(ts->hw_client,
+					  &nt36xxx_i2c_regmap_hw_config);
+	if (IS_ERR(ts->regmap)) {
+		dev_err(&hw_client->dev, "regmap (hw-addr) init failed\n");
+		return PTR_ERR(ts->regmap);
+	}
+
+	ts->fw_regmap = devm_regmap_init_i2c(ts->fw_client,
+					     &nt36xxx_i2c_regmap_fw_config);
+	if (IS_ERR(ts->fw_regmap)) {
+		dev_err(&hw_client->dev, "regmap (fw-addr) init failed\n");
+		return PTR_ERR(ts->fw_regmap);
+	}
+
+	ret = regulator_bulk_enable(NT36XXX_NUM_SUPPLIES, ts->supplies);
+	if (ret)
+		return ret;
+
+	usleep_range(10000, 11000);
+
+	ret = devm_add_action_or_reset(&hw_client->dev,
+				       nt36xxx_disable_regulators, ts);
+	if (ret)
+		return ret;
+
+	mutex_init(&ts->lock);
+
+	/* Set memory maps for the specific chip version */
+	ret = nt36xxx_i2c_chip_version_init(ts);
+	if (ret) {
+		dev_err(&hw_client->dev, "Failed to check chip version\n");
+		return ret;
+	}
+
+	/* Reset the MCU */
+	ret = nt36xxx_bootloader_reset(ts);
+	if (unlikely(ret < 0))
+		return ret;
+
+	/* Check and eventually wait until the MCU goes in reset state */
+	ret = nt36xxx_check_reset_state(ts, NT36XXX_STATE_INIT);
+	if (unlikely(ret < 0))
+		return ret;
+
+	/* Get informations from the TS firmware */
+	ret = nt36xxx_get_fw_info(ts);
+	if (unlikely(ret < 0))
+		return ret;
+
+	input->phys = devm_kasprintf(&hw_client->dev, GFP_KERNEL,
+				     "%s/input0", dev_name(&hw_client->dev));
+
+	input->name = "Novatek NT36XXX Touchscreen";
+	input->id.bustype = BUS_I2C;
+	input->dev.parent = &hw_client->dev;
+
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(EV_ABS, input->evbit);
+	input_set_capability(input, EV_KEY, BTN_TOUCH);
+
+	ret = input_mt_init_slots(input, TOUCH_MAX_FINGER_NUM,
+				  INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+	if (ret) {
+		dev_err(&hw_client->dev, "Cannot init MT slots (%d)\n", ret);
+		return ret;
+	}
+
+	input_set_abs_params(input, ABS_MT_PRESSURE, 0,
+			     TOUCH_MAX_PRESSURE, 0, 0);
+	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+			     ts->fw_info.abs_x_max - 1, 0, 0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+			     ts->fw_info.abs_y_max - 1, 0, 0);
+
+	/* Override the firmware defaults, if needed */
+	touchscreen_parse_properties(input, true, &ts->prop);
+
+	input_set_drvdata(input, ts);
+
+	ret = input_register_device(ts->input);
+	if (ret) {
+		dev_err(&hw_client->dev, "Failed to register input device: %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(&hw_client->dev, hw_client->irq, NULL,
+					nt36xxx_i2c_irq_handler, IRQF_ONESHOT,
+					hw_client->name, ts);
+	if (ret) {
+		dev_err(&hw_client->dev, "request irq failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused nt36xxx_i2c_suspend(struct device *dev)
+{
+	struct nt36xxx_i2c *ts = i2c_get_clientdata(to_i2c_client(dev));
+	int ret;
+
+	disable_irq(ts->hw_client->irq);
+
+	ret = regmap_write(ts->fw_regmap, NT36XXX_EVT_HOST_CMD,
+			   NT36XXX_CMD_ENTER_SLEEP);
+	if (unlikely(ret)) {
+		dev_err(&ts->hw_client->dev, "Cannot enter suspend!!\n");
+		return ret;
+	}
+
+	if (ts->reset_gpio)
+		gpiod_set_value(ts->reset_gpio, 1);
+
+	return 0;
+}
+
+static int __maybe_unused nt36xxx_i2c_resume(struct device *dev)
+{
+	struct nt36xxx_i2c *ts = i2c_get_clientdata(to_i2c_client(dev));
+	int ret;
+
+	mutex_lock(&ts->lock);
+
+	if (ts->reset_gpio)
+		gpiod_set_value(ts->reset_gpio, 0);
+
+	/* Reboot the MCU (also recalibrates the TS) */
+	ret = nt36xxx_bootloader_reset(ts);
+	if (ret < 0)
+		goto end;
+
+	ret = nt36xxx_check_reset_state(ts, NT36XXX_STATE_REK);
+	if (ret < 0)
+		goto end;
+
+	enable_irq(ts->hw_client->irq);
+end:
+	mutex_unlock(&ts->lock);
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(nt36xxx_i2c_pm,
+			 nt36xxx_i2c_suspend, nt36xxx_i2c_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id nt36xxx_of_match[] = {
+	{ .compatible = "novatek,nt36525" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, nt36xxx_of_match);
+#endif
+
+static const struct i2c_device_id nt36xxx_i2c_ts_id[] = {
+	{ "NVT-ts", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, nt36xxx_i2c_ts_id);
+
+static struct i2c_driver nt36xxx_i2c_ts_driver = {
+	.driver = {
+		.name	= "nt36xxx_ts",
+		.pm	= &nt36xxx_i2c_pm,
+		.of_match_table = of_match_ptr(nt36xxx_of_match),
+	},
+	.probe		= nt36xxx_i2c_probe,
+	.id_table	= nt36xxx_i2c_ts_id,
+};
+module_i2c_driver(nt36xxx_i2c_ts_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Novatek NT36XXX Touchscreen Driver");