// SPDX-License-Identifier: GPL-2.0-only
/*
 * Elan I2C/SMBus Touchpad driver - SMBus interface
 *
 * Copyright (c) 2013 ELAN Microelectronics Corp.
 *
 * Author: 林政維 (Duson Lin) <dusonlin@emc.com.tw>
 *
 * Based on cyapa driver:
 * copyright (c) 2011-2012 Cypress Semiconductor, Inc.
 * copyright (c) 2011-2012 Google, Inc.
 *
 * Trademarks are the property of their respective owners.
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>

#include "elan_i2c.h"

/* Elan SMbus commands */
#define ETP_SMBUS_IAP_CMD               0x00
#define ETP_SMBUS_ENABLE_TP             0x20
#define ETP_SMBUS_SLEEP_CMD             0x21
#define ETP_SMBUS_IAP_PASSWORD_WRITE    0x29
#define ETP_SMBUS_IAP_PASSWORD_READ     0x80
#define ETP_SMBUS_WRITE_FW_BLOCK        0x2A
#define ETP_SMBUS_IAP_RESET_CMD         0x2B
#define ETP_SMBUS_RANGE_CMD             0xA0
#define ETP_SMBUS_FW_VERSION_CMD        0xA1
#define ETP_SMBUS_XY_TRACENUM_CMD       0xA2
#define ETP_SMBUS_SM_VERSION_CMD        0xA3
#define ETP_SMBUS_UNIQUEID_CMD          0xA3
#define ETP_SMBUS_RESOLUTION_CMD        0xA4
#define ETP_SMBUS_HELLOPACKET_CMD       0xA7
#define ETP_SMBUS_PACKET_QUERY          0xA8
#define ETP_SMBUS_IAP_VERSION_CMD       0xAC
#define ETP_SMBUS_IAP_CTRL_CMD          0xAD
#define ETP_SMBUS_IAP_CHECKSUM_CMD      0xAE
#define ETP_SMBUS_FW_CHECKSUM_CMD       0xAF
#define ETP_SMBUS_MAX_BASELINE_CMD      0xC3
#define ETP_SMBUS_MIN_BASELINE_CMD      0xC4
#define ETP_SMBUS_CALIBRATE_QUERY       0xC5

#define ETP_SMBUS_REPORT_LEN            32
#define ETP_SMBUS_REPORT_LEN2           7
#define ETP_SMBUS_REPORT_OFFSET         2
#define ETP_SMBUS_HELLOPACKET_LEN       5
#define ETP_SMBUS_IAP_PASSWORD          0x1234
#define ETP_SMBUS_IAP_MODE_ON           (1 << 6)

static int elan_smbus_initialize(struct i2c_client *client)
{
        u8 check[ETP_SMBUS_HELLOPACKET_LEN] = { 0x55, 0x55, 0x55, 0x55, 0x55 };
        u8 values[I2C_SMBUS_BLOCK_MAX] = {0};
        int len, error;

        /* Get hello packet */
        len = i2c_smbus_read_block_data(client,
                                        ETP_SMBUS_HELLOPACKET_CMD, values);
        if (len != ETP_SMBUS_HELLOPACKET_LEN) {
                dev_err(&client->dev, "hello packet length fail: %d\n", len);
                error = len < 0 ? len : -EIO;
                return error;
        }

        /* compare hello packet */
        if (memcmp(values, check, ETP_SMBUS_HELLOPACKET_LEN)) {
                dev_err(&client->dev, "hello packet fail [%*ph]\n",
                        ETP_SMBUS_HELLOPACKET_LEN, values);
                return -ENXIO;
        }

        /* enable tp */
        error = i2c_smbus_write_byte(client, ETP_SMBUS_ENABLE_TP);
        if (error) {
                dev_err(&client->dev, "failed to enable touchpad: %d\n", error);
                return error;
        }

        return 0;
}

static int elan_smbus_set_mode(struct i2c_client *client, u8 mode)
{
        u8 cmd[4] = { 0x00, 0x07, 0x00, mode };

        return i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
                                          sizeof(cmd), cmd);
}

static int elan_smbus_sleep_control(struct i2c_client *client, bool sleep)
{
        if (sleep)
                return i2c_smbus_write_byte(client, ETP_SMBUS_SLEEP_CMD);
        else
                return 0; /* XXX should we send ETP_SMBUS_ENABLE_TP here? */
}

static int elan_smbus_power_control(struct i2c_client *client, bool enable)
{
        return 0; /* A no-op */
}

static int elan_smbus_calibrate(struct i2c_client *client)
{
        u8 cmd[4] = { 0x00, 0x08, 0x00, 0x01 };

        return i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
                                          sizeof(cmd), cmd);
}

static int elan_smbus_calibrate_result(struct i2c_client *client, u8 *val)
{
        int error;
        u8 buf[I2C_SMBUS_BLOCK_MAX] = {0};

        BUILD_BUG_ON(ETP_CALIBRATE_MAX_LEN > sizeof(buf));

        error = i2c_smbus_read_block_data(client,
                                          ETP_SMBUS_CALIBRATE_QUERY, buf);
        if (error < 0)
                return error;

        memcpy(val, buf, ETP_CALIBRATE_MAX_LEN);
        return 0;
}

static int elan_smbus_get_baseline_data(struct i2c_client *client,
                                        bool max_baseline, u8 *value)
{
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        error = i2c_smbus_read_block_data(client,
                                          max_baseline ?
                                                ETP_SMBUS_MAX_BASELINE_CMD :
                                                ETP_SMBUS_MIN_BASELINE_CMD,
                                          val);
        if (error < 0)
                return error;

        *value = be16_to_cpup((__be16 *)val);

        return 0;
}

static int elan_smbus_get_version(struct i2c_client *client,
                                  u8 pattern, bool iap, u8 *version)
{
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        error = i2c_smbus_read_block_data(client,
                                          iap ? ETP_SMBUS_IAP_VERSION_CMD :
                                                ETP_SMBUS_FW_VERSION_CMD,
                                          val);
        if (error < 0) {
                dev_err(&client->dev, "failed to get %s version: %d\n",
                        iap ? "IAP" : "FW", error);
                return error;
        }

        *version = val[2];
        return 0;
}

static int elan_smbus_get_sm_version(struct i2c_client *client, u8 pattern,
                                     u16 *ic_type, u8 *version, u8 *clickpad)
{
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        error = i2c_smbus_read_block_data(client,
                                          ETP_SMBUS_SM_VERSION_CMD, val);
        if (error < 0) {
                dev_err(&client->dev, "failed to get SM version: %d\n", error);
                return error;
        }

        *version = val[0];
        *ic_type = val[1];
        *clickpad = val[0] & 0x10;
        return 0;
}

static int elan_smbus_get_product_id(struct i2c_client *client, u16 *id)
{
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        error = i2c_smbus_read_block_data(client,
                                          ETP_SMBUS_UNIQUEID_CMD, val);
        if (error < 0) {
                dev_err(&client->dev, "failed to get product ID: %d\n", error);
                return error;
        }

        *id = be16_to_cpup((__be16 *)val);
        return 0;
}

static int elan_smbus_get_checksum(struct i2c_client *client,
                                   bool iap, u16 *csum)
{
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        error = i2c_smbus_read_block_data(client,
                                          iap ? ETP_SMBUS_FW_CHECKSUM_CMD :
                                                ETP_SMBUS_IAP_CHECKSUM_CMD,
                                          val);
        if (error < 0) {
                dev_err(&client->dev, "failed to get %s checksum: %d\n",
                        iap ? "IAP" : "FW", error);
                return error;
        }

        *csum = be16_to_cpup((__be16 *)val);
        return 0;
}

static int elan_smbus_get_max(struct i2c_client *client,
                              unsigned int *max_x, unsigned int *max_y)
{
        int ret;
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        ret = i2c_smbus_read_block_data(client, ETP_SMBUS_RANGE_CMD, val);
        if (ret != 3) {
                error = ret < 0 ? ret : -EIO;
                dev_err(&client->dev, "failed to get dimensions: %d\n", error);
                return error;
        }

        *max_x = (0x0f & val[0]) << 8 | val[1];
        *max_y = (0xf0 & val[0]) << 4 | val[2];

        return 0;
}

static int elan_smbus_get_resolution(struct i2c_client *client,
                                     u8 *hw_res_x, u8 *hw_res_y)
{
        int ret;
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        ret = i2c_smbus_read_block_data(client, ETP_SMBUS_RESOLUTION_CMD, val);
        if (ret != 3) {
                error = ret < 0 ? ret : -EIO;
                dev_err(&client->dev, "failed to get resolution: %d\n", error);
                return error;
        }

        *hw_res_x = val[1] & 0x0F;
        *hw_res_y = (val[1] & 0xF0) >> 4;

        return 0;
}

static int elan_smbus_get_num_traces(struct i2c_client *client,
                                     unsigned int *x_traces,
                                     unsigned int *y_traces)
{
        int ret;
        int error;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        ret = i2c_smbus_read_block_data(client, ETP_SMBUS_XY_TRACENUM_CMD, val);
        if (ret != 3) {
                error = ret < 0 ? ret : -EIO;
                dev_err(&client->dev, "failed to get trace info: %d\n", error);
                return error;
        }

        *x_traces = val[1];
        *y_traces = val[2];

        return 0;
}

static int elan_smbus_get_pressure_adjustment(struct i2c_client *client,
                                              int *adjustment)
{
        *adjustment = ETP_PRESSURE_OFFSET;
        return 0;
}

static int elan_smbus_iap_get_mode(struct i2c_client *client,
                                   enum tp_mode *mode)
{
        int error;
        u16 constant;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        error = i2c_smbus_read_block_data(client, ETP_SMBUS_IAP_CTRL_CMD, val);
        if (error < 0) {
                dev_err(&client->dev, "failed to read iap ctrol register: %d\n",
                        error);
                return error;
        }

        constant = be16_to_cpup((__be16 *)val);
        dev_dbg(&client->dev, "iap control reg: 0x%04x.\n", constant);

        *mode = (constant & ETP_SMBUS_IAP_MODE_ON) ? IAP_MODE : MAIN_MODE;

        return 0;
}

static int elan_smbus_iap_reset(struct i2c_client *client)
{
        int error;

        error = i2c_smbus_write_byte(client, ETP_SMBUS_IAP_RESET_CMD);
        if (error) {
                dev_err(&client->dev, "cannot reset IC: %d\n", error);
                return error;
        }

        return 0;
}

static int elan_smbus_set_flash_key(struct i2c_client *client)
{
        int error;
        u8 cmd[4] = { 0x00, 0x0B, 0x00, 0x5A };

        error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
                                           sizeof(cmd), cmd);
        if (error) {
                dev_err(&client->dev, "cannot set flash key: %d\n", error);
                return error;
        }

        return 0;
}

static int elan_smbus_prepare_fw_update(struct i2c_client *client, u16 ic_type,
                                        u8 iap_version, u16 fw_page_size)
{
        struct device *dev = &client->dev;
        int len;
        int error;
        enum tp_mode mode;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
        u8 cmd[4] = {0x0F, 0x78, 0x00, 0x06};
        u16 password;

        /* Get FW in which mode (IAP_MODE/MAIN_MODE)  */
        error = elan_smbus_iap_get_mode(client, &mode);
        if (error)
                return error;

        if (mode == MAIN_MODE) {

                /* set flash key */
                error = elan_smbus_set_flash_key(client);
                if (error)
                        return error;

                /* write iap password */
                if (i2c_smbus_write_byte(client,
                                         ETP_SMBUS_IAP_PASSWORD_WRITE) < 0) {
                        dev_err(dev, "cannot write iap password\n");
                        return -EIO;
                }

                error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
                                                   sizeof(cmd), cmd);
                if (error) {
                        dev_err(dev, "failed to write iap password: %d\n",
                                error);
                        return error;
                }

                /*
                 * Read back password to make sure we enabled flash
                 * successfully.
                 */
                len = i2c_smbus_read_block_data(client,
                                                ETP_SMBUS_IAP_PASSWORD_READ,
                                                val);
                if (len < (int)sizeof(u16)) {
                        error = len < 0 ? len : -EIO;
                        dev_err(dev, "failed to read iap password: %d\n",
                                error);
                        return error;
                }

                password = be16_to_cpup((__be16 *)val);
                if (password != ETP_SMBUS_IAP_PASSWORD) {
                        dev_err(dev, "wrong iap password = 0x%X\n", password);
                        return -EIO;
                }

                /* Wait 30ms for MAIN_MODE change to IAP_MODE */
                msleep(30);
        }

        error = elan_smbus_set_flash_key(client);
        if (error)
                return error;

        /* Reset IC */
        error = elan_smbus_iap_reset(client);
        if (error)
                return error;

        return 0;
}


static int elan_smbus_write_fw_block(struct i2c_client *client, u16 fw_page_size,
                                     const u8 *page, u16 checksum, int idx)
{
        struct device *dev = &client->dev;
        int error;
        u16 result;
        u8 val[I2C_SMBUS_BLOCK_MAX] = {0};

        /*
         * Due to the limitation of smbus protocol limiting
         * transfer to 32 bytes at a time, we must split block
         * in 2 transfers.
         */
        error = i2c_smbus_write_block_data(client,
                                           ETP_SMBUS_WRITE_FW_BLOCK,
                                           fw_page_size / 2,
                                           page);
        if (error) {
                dev_err(dev, "Failed to write page %d (part %d): %d\n",
                        idx, 1, error);
                return error;
        }

        error = i2c_smbus_write_block_data(client,
                                           ETP_SMBUS_WRITE_FW_BLOCK,
                                           fw_page_size / 2,
                                           page + fw_page_size / 2);
        if (error) {
                dev_err(dev, "Failed to write page %d (part %d): %d\n",
                        idx, 2, error);
                return error;
        }


        /* Wait for F/W to update one page ROM data. */
        usleep_range(8000, 10000);

        error = i2c_smbus_read_block_data(client,
                                          ETP_SMBUS_IAP_CTRL_CMD, val);
        if (error < 0) {
                dev_err(dev, "Failed to read IAP write result: %d\n",
                        error);
                return error;
        }

        result = be16_to_cpup((__be16 *)val);
        if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
                dev_err(dev, "IAP reports failed write: %04hx\n",
                        result);
                return -EIO;
        }

        return 0;
}

static int elan_smbus_get_report_features(struct i2c_client *client, u8 pattern,
                                          unsigned int *features,
                                          unsigned int *report_len)
{
        /*
         * SMBus controllers with pattern 2 lack area info, as newer
         * high-precision packets use that space for coordinates.
         */
        *features = pattern <= 0x01 ? ETP_FEATURE_REPORT_MK : 0;
        *report_len = ETP_SMBUS_REPORT_LEN;
        return 0;
}

static int elan_smbus_get_report(struct i2c_client *client,
                                 u8 *report, unsigned int report_len)
{
        int len;

        BUILD_BUG_ON(I2C_SMBUS_BLOCK_MAX > ETP_SMBUS_REPORT_LEN);

        len = i2c_smbus_read_block_data(client,
                                        ETP_SMBUS_PACKET_QUERY,
                                        &report[ETP_SMBUS_REPORT_OFFSET]);
        if (len < 0) {
                dev_err(&client->dev, "failed to read report data: %d\n", len);
                return len;
        }

        if (report[ETP_REPORT_ID_OFFSET] == ETP_TP_REPORT_ID2)
                report_len = ETP_SMBUS_REPORT_LEN2;

        if (len != report_len) {
                dev_err(&client->dev,
                        "wrong report length (%d vs %d expected)\n",
                        len, report_len);
                return -EIO;
        }

        return 0;
}

static int elan_smbus_finish_fw_update(struct i2c_client *client,
                                       struct completion *fw_completion)
{
        /* No special handling unlike I2C transport */
        return 0;
}

static int elan_smbus_get_pattern(struct i2c_client *client, u8 *pattern)
{
        *pattern = 0;
        return 0;
}

const struct elan_transport_ops elan_smbus_ops = {
        .initialize             = elan_smbus_initialize,
        .sleep_control          = elan_smbus_sleep_control,
        .power_control          = elan_smbus_power_control,
        .set_mode               = elan_smbus_set_mode,

        .calibrate              = elan_smbus_calibrate,
        .calibrate_result       = elan_smbus_calibrate_result,

        .get_baseline_data      = elan_smbus_get_baseline_data,

        .get_version            = elan_smbus_get_version,
        .get_sm_version         = elan_smbus_get_sm_version,
        .get_product_id         = elan_smbus_get_product_id,
        .get_checksum           = elan_smbus_get_checksum,
        .get_pressure_adjustment = elan_smbus_get_pressure_adjustment,

        .get_max                = elan_smbus_get_max,
        .get_resolution         = elan_smbus_get_resolution,
        .get_num_traces         = elan_smbus_get_num_traces,

        .iap_get_mode           = elan_smbus_iap_get_mode,
        .iap_reset              = elan_smbus_iap_reset,

        .prepare_fw_update      = elan_smbus_prepare_fw_update,
        .write_fw_block         = elan_smbus_write_fw_block,
        .finish_fw_update       = elan_smbus_finish_fw_update,

        .get_report_features    = elan_smbus_get_report_features,
        .get_report             = elan_smbus_get_report,
        .get_pattern            = elan_smbus_get_pattern,
};