// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 Broadcom Corporation
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/keyboard.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <asm/irq.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/serio.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#define IPROC_TS_NAME "iproc-ts"

#define PEN_DOWN_STATUS     1
#define PEN_UP_STATUS       0

#define X_MIN               0
#define Y_MIN               0
#define X_MAX               0xFFF
#define Y_MAX               0xFFF

/* Value given by controller for invalid coordinate. */
#define INVALID_COORD       0xFFFFFFFF

/* Register offsets */
#define REGCTL1             0x00
#define REGCTL2             0x04
#define INTERRUPT_THRES     0x08
#define INTERRUPT_MASK      0x0c

#define INTERRUPT_STATUS    0x10
#define CONTROLLER_STATUS   0x14
#define FIFO_DATA           0x18
#define FIFO_DATA_X_Y_MASK  0xFFFF
#define ANALOG_CONTROL      0x1c

#define AUX_DATA            0x20
#define DEBOUNCE_CNTR_STAT  0x24
#define SCAN_CNTR_STAT      0x28
#define REM_CNTR_STAT       0x2c

#define SETTLING_TIMER_STAT 0x30
#define SPARE_REG           0x34
#define SOFT_BYPASS_CONTROL 0x38
#define SOFT_BYPASS_DATA    0x3c


/* Bit values for INTERRUPT_MASK and INTERRUPT_STATUS regs */
#define TS_PEN_INTR_MASK        BIT(0)
#define TS_FIFO_INTR_MASK       BIT(2)

/* Bit values for CONTROLLER_STATUS reg1 */
#define TS_PEN_DOWN             BIT(0)

/* Shift values for control reg1 */
#define SCANNING_PERIOD_SHIFT   24
#define DEBOUNCE_TIMEOUT_SHIFT  16
#define SETTLING_TIMEOUT_SHIFT  8
#define TOUCH_TIMEOUT_SHIFT     0

/* Shift values for coordinates from fifo */
#define X_COORD_SHIFT  0
#define Y_COORD_SHIFT  16

/* Bit values for REGCTL2 */
#define TS_CONTROLLER_EN_BIT    BIT(16)
#define TS_CONTROLLER_AVGDATA_SHIFT 8
#define TS_CONTROLLER_AVGDATA_MASK (0x7 << TS_CONTROLLER_AVGDATA_SHIFT)
#define TS_CONTROLLER_PWR_LDO   BIT(5)
#define TS_CONTROLLER_PWR_ADC   BIT(4)
#define TS_CONTROLLER_PWR_BGP   BIT(3)
#define TS_CONTROLLER_PWR_TS    BIT(2)
#define TS_WIRE_MODE_BIT        BIT(1)

#define dbg_reg(dev, priv, reg) \
do { \
        u32 val; \
        regmap_read(priv->regmap, reg, &val); \
        dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
} while (0)

struct tsc_param {
        /* Each step is 1024 us.  Valid 1-256 */
        u32 scanning_period;

        /*  Each step is 512 us.  Valid 0-255 */
        u32 debounce_timeout;

        /*
         * The settling duration (in ms) is the amount of time the tsc
         * waits to allow the voltage to settle after turning on the
         * drivers in detection mode. Valid values: 0-11
         *   0 =  0.008 ms
         *   1 =  0.01 ms
         *   2 =  0.02 ms
         *   3 =  0.04 ms
         *   4 =  0.08 ms
         *   5 =  0.16 ms
         *   6 =  0.32 ms
         *   7 =  0.64 ms
         *   8 =  1.28 ms
         *   9 =  2.56 ms
         *   10 = 5.12 ms
         *   11 = 10.24 ms
         */
        u32 settling_timeout;

        /* touch timeout in sample counts */
        u32 touch_timeout;

        /*
         * Number of data samples which are averaged before a final data point
         * is placed into the FIFO
         */
        u32 average_data;

        /* FIFO threshold */
        u32 fifo_threshold;

        /* Optional standard touchscreen properties. */
        u32 max_x;
        u32 max_y;
        u32 fuzz_x;
        u32 fuzz_y;
        bool invert_x;
        bool invert_y;
};

struct iproc_ts_priv {
        struct platform_device *pdev;
        struct input_dev *idev;

        struct regmap *regmap;
        struct clk *tsc_clk;

        int  pen_status;
        struct tsc_param cfg_params;
};

/*
 * Set default values the same as hardware reset values
 * except for fifo_threshold with is set to 1.
 */
static const struct tsc_param iproc_default_config = {
        .scanning_period  = 0x5,  /* 1 to 256 */
        .debounce_timeout = 0x28, /* 0 to 255 */
        .settling_timeout = 0x7,  /* 0 to 11 */
        .touch_timeout    = 0xa,  /* 0 to 255 */
        .average_data     = 5,    /* entry 5 = 32 pts */
        .fifo_threshold   = 1,    /* 0 to 31 */
        .max_x            = X_MAX,
        .max_y            = Y_MAX,
};

static void ts_reg_dump(struct iproc_ts_priv *priv)
{
        struct device *dev = &priv->pdev->dev;

        dbg_reg(dev, priv, REGCTL1);
        dbg_reg(dev, priv, REGCTL2);
        dbg_reg(dev, priv, INTERRUPT_THRES);
        dbg_reg(dev, priv, INTERRUPT_MASK);
        dbg_reg(dev, priv, INTERRUPT_STATUS);
        dbg_reg(dev, priv, CONTROLLER_STATUS);
        dbg_reg(dev, priv, FIFO_DATA);
        dbg_reg(dev, priv, ANALOG_CONTROL);
        dbg_reg(dev, priv, AUX_DATA);
        dbg_reg(dev, priv, DEBOUNCE_CNTR_STAT);
        dbg_reg(dev, priv, SCAN_CNTR_STAT);
        dbg_reg(dev, priv, REM_CNTR_STAT);
        dbg_reg(dev, priv, SETTLING_TIMER_STAT);
        dbg_reg(dev, priv, SPARE_REG);
        dbg_reg(dev, priv, SOFT_BYPASS_CONTROL);
        dbg_reg(dev, priv, SOFT_BYPASS_DATA);
}

static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data)
{
        struct platform_device *pdev = data;
        struct iproc_ts_priv *priv = platform_get_drvdata(pdev);
        u32 intr_status;
        u32 raw_coordinate;
        u16 x;
        u16 y;
        int i;
        bool needs_sync = false;

        regmap_read(priv->regmap, INTERRUPT_STATUS, &intr_status);
        intr_status &= TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
        if (intr_status == 0)
                return IRQ_NONE;

        /* Clear all interrupt status bits, write-1-clear */
        regmap_write(priv->regmap, INTERRUPT_STATUS, intr_status);
        /* Pen up/down */
        if (intr_status & TS_PEN_INTR_MASK) {
                regmap_read(priv->regmap, CONTROLLER_STATUS, &priv->pen_status);
                if (priv->pen_status & TS_PEN_DOWN)
                        priv->pen_status = PEN_DOWN_STATUS;
                else
                        priv->pen_status = PEN_UP_STATUS;

                input_report_key(priv->idev, BTN_TOUCH, priv->pen_status);
                needs_sync = true;

                dev_dbg(&priv->pdev->dev,
                        "pen up-down (%d)\n", priv->pen_status);
        }

        /* coordinates in FIFO exceed the threshold */
        if (intr_status & TS_FIFO_INTR_MASK) {
                for (i = 0; i < priv->cfg_params.fifo_threshold; i++) {
                        regmap_read(priv->regmap, FIFO_DATA, &raw_coordinate);
                        if (raw_coordinate == INVALID_COORD)
                                continue;

                        /*
                         * The x and y coordinate are 16 bits each
                         * with the x in the lower 16 bits and y in the
                         * upper 16 bits.
                         */
                        x = (raw_coordinate >> X_COORD_SHIFT) &
                                FIFO_DATA_X_Y_MASK;
                        y = (raw_coordinate >> Y_COORD_SHIFT) &
                                FIFO_DATA_X_Y_MASK;

                        /* We only want to retain the 12 msb of the 16 */
                        x = (x >> 4) & 0x0FFF;
                        y = (y >> 4) & 0x0FFF;

                        /* Adjust x y according to LCD tsc mount angle. */
                        if (priv->cfg_params.invert_x)
                                x = priv->cfg_params.max_x - x;

                        if (priv->cfg_params.invert_y)
                                y = priv->cfg_params.max_y - y;

                        input_report_abs(priv->idev, ABS_X, x);
                        input_report_abs(priv->idev, ABS_Y, y);
                        needs_sync = true;

                        dev_dbg(&priv->pdev->dev, "xy (0x%x 0x%x)\n", x, y);
                }
        }

        if (needs_sync)
                input_sync(priv->idev);

        return IRQ_HANDLED;
}

static int iproc_ts_start(struct input_dev *idev)
{
        u32 val;
        u32 mask;
        int error;
        struct iproc_ts_priv *priv = input_get_drvdata(idev);

        /* Enable clock */
        error = clk_prepare_enable(priv->tsc_clk);
        if (error) {
                dev_err(&priv->pdev->dev, "%s clk_prepare_enable failed %d\n",
                        __func__, error);
                return error;
        }

        /*
         * Interrupt is generated when:
         *  FIFO reaches the int_th value, and pen event(up/down)
         */
        val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
        regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, val);

        val = priv->cfg_params.fifo_threshold;
        regmap_write(priv->regmap, INTERRUPT_THRES, val);

        /* Initialize control reg1 */
        val = 0;
        val |= priv->cfg_params.scanning_period << SCANNING_PERIOD_SHIFT;
        val |= priv->cfg_params.debounce_timeout << DEBOUNCE_TIMEOUT_SHIFT;
        val |= priv->cfg_params.settling_timeout << SETTLING_TIMEOUT_SHIFT;
        val |= priv->cfg_params.touch_timeout << TOUCH_TIMEOUT_SHIFT;
        regmap_write(priv->regmap, REGCTL1, val);

        /* Try to clear all interrupt status */
        val = TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;
        regmap_update_bits(priv->regmap, INTERRUPT_STATUS, val, val);

        /* Initialize control reg2 */
        val = TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;
        val |= priv->cfg_params.average_data << TS_CONTROLLER_AVGDATA_SHIFT;

        mask = (TS_CONTROLLER_AVGDATA_MASK);
        mask |= (TS_CONTROLLER_PWR_LDO |        /* PWR up LDO */
                   TS_CONTROLLER_PWR_ADC |      /* PWR up ADC */
                   TS_CONTROLLER_PWR_BGP |      /* PWR up BGP */
                   TS_CONTROLLER_PWR_TS);       /* PWR up TS */
        mask |= val;
        regmap_update_bits(priv->regmap, REGCTL2, mask, val);

        ts_reg_dump(priv);

        return 0;
}

static void iproc_ts_stop(struct input_dev *dev)
{
        u32 val;
        struct iproc_ts_priv *priv = input_get_drvdata(dev);

        /*
         * Disable FIFO int_th and pen event(up/down)Interrupts only
         * as the interrupt mask register is shared between ADC, TS and
         * flextimer.
         */
        val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
        regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, 0);

        /* Only power down touch screen controller */
        val = TS_CONTROLLER_PWR_TS;
        regmap_update_bits(priv->regmap, REGCTL2, val, val);

        clk_disable(priv->tsc_clk);
}

static int iproc_get_tsc_config(struct device *dev, struct iproc_ts_priv *priv)
{
        struct device_node *np = dev->of_node;
        u32 val;

        priv->cfg_params = iproc_default_config;

        if (!np)
                return 0;

        if (of_property_read_u32(np, "scanning_period", &val) >= 0) {
                if (val < 1 || val > 256) {
                        dev_err(dev, "scanning_period (%u) must be [1-256]\n",
                                val);
                        return -EINVAL;
                }
                priv->cfg_params.scanning_period = val;
        }

        if (of_property_read_u32(np, "debounce_timeout", &val) >= 0) {
                if (val > 255) {
                        dev_err(dev, "debounce_timeout (%u) must be [0-255]\n",
                                val);
                        return -EINVAL;
                }
                priv->cfg_params.debounce_timeout = val;
        }

        if (of_property_read_u32(np, "settling_timeout", &val) >= 0) {
                if (val > 11) {
                        dev_err(dev, "settling_timeout (%u) must be [0-11]\n",
                                val);
                        return -EINVAL;
                }
                priv->cfg_params.settling_timeout = val;
        }

        if (of_property_read_u32(np, "touch_timeout", &val) >= 0) {
                if (val > 255) {
                        dev_err(dev, "touch_timeout (%u) must be [0-255]\n",
                                val);
                        return -EINVAL;
                }
                priv->cfg_params.touch_timeout = val;
        }

        if (of_property_read_u32(np, "average_data", &val) >= 0) {
                if (val > 8) {
                        dev_err(dev, "average_data (%u) must be [0-8]\n", val);
                        return -EINVAL;
                }
                priv->cfg_params.average_data = val;
        }

        if (of_property_read_u32(np, "fifo_threshold", &val) >= 0) {
                if (val > 31) {
                        dev_err(dev, "fifo_threshold (%u)) must be [0-31]\n",
                                val);
                        return -EINVAL;
                }
                priv->cfg_params.fifo_threshold = val;
        }

        /* Parse optional properties. */
        of_property_read_u32(np, "touchscreen-size-x", &priv->cfg_params.max_x);
        of_property_read_u32(np, "touchscreen-size-y", &priv->cfg_params.max_y);

        of_property_read_u32(np, "touchscreen-fuzz-x",
                             &priv->cfg_params.fuzz_x);
        of_property_read_u32(np, "touchscreen-fuzz-y",
                             &priv->cfg_params.fuzz_y);

        priv->cfg_params.invert_x =
                of_property_read_bool(np, "touchscreen-inverted-x");
        priv->cfg_params.invert_y =
                of_property_read_bool(np, "touchscreen-inverted-y");

        return 0;
}

static int iproc_ts_probe(struct platform_device *pdev)
{
        struct iproc_ts_priv *priv;
        struct input_dev *idev;
        int irq;
        int error;

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

        /* touchscreen controller memory mapped regs via syscon*/
        priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
                                                        "ts_syscon");
        if (IS_ERR(priv->regmap)) {
                error = PTR_ERR(priv->regmap);
                dev_err(&pdev->dev, "unable to map I/O memory:%d\n", error);
                return error;
        }

        priv->tsc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
        if (IS_ERR(priv->tsc_clk)) {
                error = PTR_ERR(priv->tsc_clk);
                dev_err(&pdev->dev,
                        "failed getting clock tsc_clk: %d\n", error);
                return error;
        }

        priv->pdev = pdev;
        error = iproc_get_tsc_config(&pdev->dev, priv);
        if (error) {
                dev_err(&pdev->dev, "get_tsc_config failed: %d\n", error);
                return error;
        }

        idev = devm_input_allocate_device(&pdev->dev);
        if (!idev) {
                dev_err(&pdev->dev, "failed to allocate input device\n");
                return -ENOMEM;
        }

        priv->idev = idev;
        priv->pen_status = PEN_UP_STATUS;

        /* Set input device info  */
        idev->name = IPROC_TS_NAME;
        idev->dev.parent = &pdev->dev;

        idev->id.bustype = BUS_HOST;
        idev->id.vendor = SERIO_UNKNOWN;
        idev->id.product = 0;
        idev->id.version = 0;

        idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
        __set_bit(BTN_TOUCH, idev->keybit);

        input_set_abs_params(idev, ABS_X, X_MIN, priv->cfg_params.max_x,
                             priv->cfg_params.fuzz_x, 0);
        input_set_abs_params(idev, ABS_Y, Y_MIN, priv->cfg_params.max_y,
                             priv->cfg_params.fuzz_y, 0);

        idev->open = iproc_ts_start;
        idev->close = iproc_ts_stop;

        input_set_drvdata(idev, priv);
        platform_set_drvdata(pdev, priv);

        /* get interrupt */
        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        error = devm_request_irq(&pdev->dev, irq,
                                 iproc_touchscreen_interrupt,
                                 IRQF_SHARED, IPROC_TS_NAME, pdev);
        if (error)
                return error;

        error = input_register_device(priv->idev);
        if (error) {
                dev_err(&pdev->dev,
                        "failed to register input device: %d\n", error);
                return error;
        }

        return 0;
}

static const struct of_device_id iproc_ts_of_match[] = {
        {.compatible = "brcm,iproc-touchscreen", },
        { },
};
MODULE_DEVICE_TABLE(of, iproc_ts_of_match);

static struct platform_driver iproc_ts_driver = {
        .probe = iproc_ts_probe,
        .driver = {
                .name   = IPROC_TS_NAME,
                .of_match_table = iproc_ts_of_match,
        },
};

module_platform_driver(iproc_ts_driver);

MODULE_DESCRIPTION("IPROC Touchscreen driver");
MODULE_AUTHOR("Broadcom");
MODULE_LICENSE("GPL v2");