root/drivers/input/rmi4/rmi_f30.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012-2016 Synaptics Incorporated
 */

#include <linux/kernel.h>
#include <linux/rmi.h>
#include <linux/input.h>
#include <linux/slab.h>
#include "rmi_driver.h"

#define RMI_F30_QUERY_SIZE                      2

/* Defs for Query 0 */
#define RMI_F30_EXTENDED_PATTERNS               0x01
#define RMI_F30_HAS_MAPPABLE_BUTTONS            BIT(1)
#define RMI_F30_HAS_LED                         BIT(2)
#define RMI_F30_HAS_GPIO                        BIT(3)
#define RMI_F30_HAS_HAPTIC                      BIT(4)
#define RMI_F30_HAS_GPIO_DRV_CTL                BIT(5)
#define RMI_F30_HAS_MECH_MOUSE_BTNS             BIT(6)

/* Defs for Query 1 */
#define RMI_F30_GPIO_LED_COUNT                  0x1F

/* Defs for Control Registers */
#define RMI_F30_CTRL_1_GPIO_DEBOUNCE            0x01
#define RMI_F30_CTRL_1_HALT                     BIT(4)
#define RMI_F30_CTRL_1_HALTED                   BIT(5)
#define RMI_F30_CTRL_10_NUM_MECH_MOUSE_BTNS     0x03

#define RMI_F30_CTRL_MAX_REGS           32
#define RMI_F30_CTRL_MAX_BYTES          DIV_ROUND_UP(RMI_F30_CTRL_MAX_REGS, 8)
#define RMI_F30_CTRL_MAX_REG_BLOCKS     11

#define RMI_F30_CTRL_REGS_MAX_SIZE (RMI_F30_CTRL_MAX_BYTES              \
                                        + 1                             \
                                        + RMI_F30_CTRL_MAX_BYTES        \
                                        + RMI_F30_CTRL_MAX_BYTES        \
                                        + RMI_F30_CTRL_MAX_BYTES        \
                                        + 6                             \
                                        + RMI_F30_CTRL_MAX_REGS         \
                                        + RMI_F30_CTRL_MAX_REGS         \
                                        + RMI_F30_CTRL_MAX_BYTES        \
                                        + 1                             \
                                        + 1)

#define TRACKSTICK_RANGE_START          3
#define TRACKSTICK_RANGE_END            6

struct rmi_f30_ctrl_data {
        int address;
        int length;
        u8 *regs;
};

struct f30_data {
        /* Query Data */
        bool has_extended_pattern;
        bool has_mappable_buttons;
        bool has_led;
        bool has_gpio;
        bool has_haptic;
        bool has_gpio_driver_control;
        bool has_mech_mouse_btns;
        u8 gpioled_count;

        u8 register_count;

        /* Control Register Data */
        struct rmi_f30_ctrl_data ctrl[RMI_F30_CTRL_MAX_REG_BLOCKS];
        u8 ctrl_regs[RMI_F30_CTRL_REGS_MAX_SIZE];
        u32 ctrl_regs_size;

        u8 data_regs[RMI_F30_CTRL_MAX_BYTES];
        u16 *gpioled_key_map;

        struct input_dev *input;

        struct rmi_function *f03;
        bool trackstick_buttons;
};

static int rmi_f30_read_control_parameters(struct rmi_function *fn,
                                                struct f30_data *f30)
{
        int error;

        error = rmi_read_block(fn->rmi_dev, fn->fd.control_base_addr,
                               f30->ctrl_regs, f30->ctrl_regs_size);
        if (error) {
                dev_err(&fn->dev,
                        "%s: Could not read control registers at 0x%x: %d\n",
                        __func__, fn->fd.control_base_addr, error);
                return error;
        }

        return 0;
}

static void rmi_f30_report_button(struct rmi_function *fn,
                                  struct f30_data *f30, unsigned int button)
{
        unsigned int reg_num = button >> 3;
        unsigned int bit_num = button & 0x07;
        u16 key_code = f30->gpioled_key_map[button];
        bool key_down = !(f30->data_regs[reg_num] & BIT(bit_num));

        if (f30->trackstick_buttons &&
            button >= TRACKSTICK_RANGE_START &&
            button <= TRACKSTICK_RANGE_END) {
                rmi_f03_overwrite_button(f30->f03, key_code, key_down);
        } else {
                rmi_dbg(RMI_DEBUG_FN, &fn->dev,
                        "%s: call input report key (0x%04x) value (0x%02x)",
                        __func__, key_code, key_down);

                input_report_key(f30->input, key_code, key_down);
        }
}

static irqreturn_t rmi_f30_attention(int irq, void *ctx)
{
        struct rmi_function *fn = ctx;
        struct f30_data *f30 = dev_get_drvdata(&fn->dev);
        struct rmi_driver_data *drvdata = dev_get_drvdata(&fn->rmi_dev->dev);
        int error;
        int i;

        /* Read the gpi led data. */
        if (drvdata->attn_data.data) {
                if (drvdata->attn_data.size < f30->register_count) {
                        dev_warn(&fn->dev,
                                 "F30 interrupted, but data is missing\n");
                        return IRQ_HANDLED;
                }
                memcpy(f30->data_regs, drvdata->attn_data.data,
                        f30->register_count);
                drvdata->attn_data.data += f30->register_count;
                drvdata->attn_data.size -= f30->register_count;
        } else {
                error = rmi_read_block(fn->rmi_dev, fn->fd.data_base_addr,
                                       f30->data_regs, f30->register_count);
                if (error) {
                        dev_err(&fn->dev,
                                "%s: Failed to read F30 data registers: %d\n",
                                __func__, error);
                        return IRQ_RETVAL(error);
                }
        }

        if (f30->has_gpio) {
                for (i = 0; i < f30->gpioled_count; i++)
                        if (f30->gpioled_key_map[i] != KEY_RESERVED)
                                rmi_f30_report_button(fn, f30, i);
                if (f30->trackstick_buttons)
                        rmi_f03_commit_buttons(f30->f03);
        }

        return IRQ_HANDLED;
}

static int rmi_f30_config(struct rmi_function *fn)
{
        struct f30_data *f30 = dev_get_drvdata(&fn->dev);
        struct rmi_driver *drv = fn->rmi_dev->driver;
        const struct rmi_device_platform_data *pdata =
                                rmi_get_platform_data(fn->rmi_dev);
        int error;

        /* can happen if gpio_data.disable is set */
        if (!f30)
                return 0;

        if (pdata->gpio_data.trackstick_buttons) {
                /* Try [re-]establish link to F03. */
                f30->f03 = rmi_find_function(fn->rmi_dev, 0x03);
                f30->trackstick_buttons = f30->f03 != NULL;
        }

        if (pdata->gpio_data.disable) {
                drv->clear_irq_bits(fn->rmi_dev, fn->irq_mask);
        } else {
                /* Write Control Register values back to device */
                error = rmi_write_block(fn->rmi_dev, fn->fd.control_base_addr,
                                        f30->ctrl_regs, f30->ctrl_regs_size);
                if (error) {
                        dev_err(&fn->dev,
                                "%s: Could not write control registers at 0x%x: %d\n",
                                __func__, fn->fd.control_base_addr, error);
                        return error;
                }

                drv->set_irq_bits(fn->rmi_dev, fn->irq_mask);
        }

        return 0;
}

static void rmi_f30_set_ctrl_data(struct rmi_f30_ctrl_data *ctrl,
                                  int *ctrl_addr, int len, u8 **reg)
{
        ctrl->address = *ctrl_addr;
        ctrl->length = len;
        ctrl->regs = *reg;
        *ctrl_addr += len;
        *reg += len;
}

static bool rmi_f30_is_valid_button(int button, struct rmi_f30_ctrl_data *ctrl)
{
        int byte_position = button >> 3;
        int bit_position = button & 0x07;

        /*
         * ctrl2 -> dir == 0 -> input mode
         * ctrl3 -> data == 1 -> actual button
         */
        return !(ctrl[2].regs[byte_position] & BIT(bit_position)) &&
                (ctrl[3].regs[byte_position] & BIT(bit_position));
}

static int rmi_f30_map_gpios(struct rmi_function *fn,
                             struct f30_data *f30)
{
        const struct rmi_device_platform_data *pdata =
                                        rmi_get_platform_data(fn->rmi_dev);
        struct input_dev *input = f30->input;
        unsigned int button = BTN_LEFT;
        unsigned int trackstick_button = BTN_LEFT;
        bool button_mapped = false;
        int i;
        int button_count = min_t(u8, f30->gpioled_count, TRACKSTICK_RANGE_END);

        f30->gpioled_key_map = devm_kcalloc(&fn->dev,
                                            button_count,
                                            sizeof(f30->gpioled_key_map[0]),
                                            GFP_KERNEL);
        if (!f30->gpioled_key_map) {
                dev_err(&fn->dev, "Failed to allocate gpioled map memory.\n");
                return -ENOMEM;
        }

        for (i = 0; i < button_count; i++) {
                if (!rmi_f30_is_valid_button(i, f30->ctrl))
                        continue;

                if (pdata->gpio_data.trackstick_buttons &&
                    i >= TRACKSTICK_RANGE_START && i < TRACKSTICK_RANGE_END) {
                        f30->gpioled_key_map[i] = trackstick_button++;
                } else if (!pdata->gpio_data.buttonpad || !button_mapped) {
                        f30->gpioled_key_map[i] = button;
                        input_set_capability(input, EV_KEY, button++);
                        button_mapped = true;
                }
        }

        input->keycode = f30->gpioled_key_map;
        input->keycodesize = sizeof(f30->gpioled_key_map[0]);
        input->keycodemax = f30->gpioled_count;

        /*
         * Buttonpad could be also inferred from f30->has_mech_mouse_btns,
         * but I am not sure, so use only the pdata info and the number of
         * mapped buttons.
         */
        if (pdata->gpio_data.buttonpad || (button - BTN_LEFT == 1))
                __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);

        return 0;
}

static int rmi_f30_initialize(struct rmi_function *fn, struct f30_data *f30)
{
        u8 *ctrl_reg = f30->ctrl_regs;
        int control_address = fn->fd.control_base_addr;
        u8 buf[RMI_F30_QUERY_SIZE];
        int error;

        error = rmi_read_block(fn->rmi_dev, fn->fd.query_base_addr,
                               buf, RMI_F30_QUERY_SIZE);
        if (error) {
                dev_err(&fn->dev, "Failed to read query register\n");
                return error;
        }

        f30->has_extended_pattern = buf[0] & RMI_F30_EXTENDED_PATTERNS;
        f30->has_mappable_buttons = buf[0] & RMI_F30_HAS_MAPPABLE_BUTTONS;
        f30->has_led = buf[0] & RMI_F30_HAS_LED;
        f30->has_gpio = buf[0] & RMI_F30_HAS_GPIO;
        f30->has_haptic = buf[0] & RMI_F30_HAS_HAPTIC;
        f30->has_gpio_driver_control = buf[0] & RMI_F30_HAS_GPIO_DRV_CTL;
        f30->has_mech_mouse_btns = buf[0] & RMI_F30_HAS_MECH_MOUSE_BTNS;
        f30->gpioled_count = buf[1] & RMI_F30_GPIO_LED_COUNT;

        f30->register_count = DIV_ROUND_UP(f30->gpioled_count, 8);

        if (f30->has_gpio && f30->has_led)
                rmi_f30_set_ctrl_data(&f30->ctrl[0], &control_address,
                                      f30->register_count, &ctrl_reg);

        rmi_f30_set_ctrl_data(&f30->ctrl[1], &control_address,
                              sizeof(u8), &ctrl_reg);

        if (f30->has_gpio) {
                rmi_f30_set_ctrl_data(&f30->ctrl[2], &control_address,
                                      f30->register_count, &ctrl_reg);

                rmi_f30_set_ctrl_data(&f30->ctrl[3], &control_address,
                                      f30->register_count, &ctrl_reg);
        }

        if (f30->has_led) {
                rmi_f30_set_ctrl_data(&f30->ctrl[4], &control_address,
                                      f30->register_count, &ctrl_reg);

                rmi_f30_set_ctrl_data(&f30->ctrl[5], &control_address,
                                      f30->has_extended_pattern ? 6 : 2,
                                      &ctrl_reg);
        }

        if (f30->has_led || f30->has_gpio_driver_control) {
                /* control 6 uses a byte per gpio/led */
                rmi_f30_set_ctrl_data(&f30->ctrl[6], &control_address,
                                      f30->gpioled_count, &ctrl_reg);
        }

        if (f30->has_mappable_buttons) {
                /* control 7 uses a byte per gpio/led */
                rmi_f30_set_ctrl_data(&f30->ctrl[7], &control_address,
                                      f30->gpioled_count, &ctrl_reg);
        }

        if (f30->has_haptic) {
                rmi_f30_set_ctrl_data(&f30->ctrl[8], &control_address,
                                      f30->register_count, &ctrl_reg);

                rmi_f30_set_ctrl_data(&f30->ctrl[9], &control_address,
                                      sizeof(u8), &ctrl_reg);
        }

        if (f30->has_mech_mouse_btns)
                rmi_f30_set_ctrl_data(&f30->ctrl[10], &control_address,
                                      sizeof(u8), &ctrl_reg);

        f30->ctrl_regs_size = ctrl_reg -
                                f30->ctrl_regs ?: RMI_F30_CTRL_REGS_MAX_SIZE;

        error = rmi_f30_read_control_parameters(fn, f30);
        if (error) {
                dev_err(&fn->dev,
                        "Failed to initialize F30 control params: %d\n",
                        error);
                return error;
        }

        if (f30->has_gpio) {
                error = rmi_f30_map_gpios(fn, f30);
                if (error)
                        return error;
        }

        return 0;
}

static int rmi_f30_probe(struct rmi_function *fn)
{
        struct rmi_device *rmi_dev = fn->rmi_dev;
        const struct rmi_device_platform_data *pdata =
                                        rmi_get_platform_data(rmi_dev);
        struct rmi_driver_data *drv_data = dev_get_drvdata(&rmi_dev->dev);
        struct f30_data *f30;
        int error;

        if (pdata->gpio_data.disable)
                return 0;

        if (!drv_data->input) {
                dev_info(&fn->dev, "F30: no input device found, ignoring\n");
                return -ENXIO;
        }

        f30 = devm_kzalloc(&fn->dev, sizeof(*f30), GFP_KERNEL);
        if (!f30)
                return -ENOMEM;

        f30->input = drv_data->input;

        error = rmi_f30_initialize(fn, f30);
        if (error)
                return error;

        dev_set_drvdata(&fn->dev, f30);
        return 0;
}

struct rmi_function_handler rmi_f30_handler = {
        .driver = {
                .name = "rmi4_f30",
        },
        .func = 0x30,
        .probe = rmi_f30_probe,
        .config = rmi_f30_config,
        .attention = rmi_f30_attention,
};