// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 * Copyright (c) 2010-2011 NVIDIA Corporation
 *  NVIDIA Corporation <www.nvidia.com>
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <log.h>
#include <asm/io.h>
#include <clk.h>
#include <reset.h>
#ifndef CONFIG_TEGRA186
#include <asm/arch/clock.h>
#include <asm/arch/funcmux.h>
#endif
#include <asm/arch/gpio.h>
#include <asm/arch-tegra/tegra_i2c.h>
#include <linux/delay.h>
#include <linux/err.h>

enum i2c_type {
        TYPE_114,
        TYPE_STD,
        TYPE_DVC,
};

/* Information about i2c controller */
struct i2c_bus {
        int                     id;
        struct reset_ctl        reset_ctl;
        struct clk              clk;
        int                     speed;
        int                     pinmux_config;
        struct i2c_control      *control;
        struct i2c_ctlr         *regs;
        enum i2c_type           type;
        int                     inited; /* bus is inited */
};

static void set_packet_mode(struct i2c_bus *i2c_bus)
{
        u32 config;

        config = I2C_CNFG_NEW_MASTER_FSM_MASK | I2C_CNFG_PACKET_MODE_MASK;

        if (i2c_bus->type == TYPE_DVC) {
                struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;

                writel(config, &dvc->cnfg);
        } else {
                writel(config, &i2c_bus->regs->cnfg);
                /*
                 * program I2C_SL_CNFG.NEWSL to ENABLE. This fixes probe
                 * issues, i.e., some slaves may be wrongly detected.
                 */
                setbits_le32(&i2c_bus->regs->sl_cnfg, I2C_SL_CNFG_NEWSL_MASK);
        }
}

static void i2c_reset_controller(struct i2c_bus *i2c_bus)
{
        /* Reset I2C controller. */
        reset_assert(&i2c_bus->reset_ctl);
        udelay(1);
        reset_deassert(&i2c_bus->reset_ctl);
        udelay(1);

        /* re-program config register to packet mode */
        set_packet_mode(i2c_bus);
}

static int i2c_init_clock(struct i2c_bus *i2c_bus, unsigned rate)
{
        int ret;

        ret = reset_assert(&i2c_bus->reset_ctl);
        if (ret)
                return ret;
        ret = clk_enable(&i2c_bus->clk);
        if (ret)
                return ret;
        ret = clk_set_rate(&i2c_bus->clk, rate);
        if (IS_ERR_VALUE(ret))
                return ret;
        ret = reset_deassert(&i2c_bus->reset_ctl);
        if (ret)
                return ret;

        return 0;
}

static void i2c_init_controller(struct i2c_bus *i2c_bus)
{
        if (!i2c_bus->speed)
                return;
        debug("%s: speed=%d\n", __func__, i2c_bus->speed);
        /*
         * Use PLLP - DP-04508-001_v06 datasheet indicates a divisor of 8
         * here, in section 23.3.1, but in fact we seem to need a factor of
         * 16 to get the right frequency.
         */
        i2c_init_clock(i2c_bus, i2c_bus->speed * 2 * 8);

        if (i2c_bus->type == TYPE_114) {
                /*
                 * T114 I2C went to a single clock source for standard/fast and
                 * HS clock speeds. The new clock rate setting calculation is:
                 *  SCL = CLK_SOURCE.I2C /
                 *   (CLK_MULT_STD_FAST_MODE * (I2C_CLK_DIV_STD_FAST_MODE+1) *
                 *   I2C FREQUENCY DIVISOR) as per the T114 TRM (sec 30.3.1).
                 *
                 * NOTE: We do this here, after the initial clock/pll start,
                 * because if we read the clk_div reg before the controller
                 * is running, we hang, and we need it for the new calc.
                 */
                int clk_div_stdfst_mode = readl(&i2c_bus->regs->clk_div) >> 16;
                unsigned rate = CLK_MULT_STD_FAST_MODE *
                                (clk_div_stdfst_mode + 1) * i2c_bus->speed * 2;
                debug("%s: CLK_DIV_STD_FAST_MODE setting = %d\n", __func__,
                        clk_div_stdfst_mode);

                i2c_init_clock(i2c_bus, rate);
        }

        /* Reset I2C controller. */
        i2c_reset_controller(i2c_bus);

        /* Configure I2C controller. */
        if (i2c_bus->type == TYPE_DVC) {        /* only for DVC I2C */
                struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;

                setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK);
        }

#ifndef CONFIG_TEGRA186
        funcmux_select(i2c_bus->clk.id, i2c_bus->pinmux_config);
#endif
}

static void send_packet_headers(
        struct i2c_bus *i2c_bus,
        struct i2c_trans_info *trans,
        u32 packet_id,
        bool end_with_repeated_start)
{
        u32 data;

        /* prepare header1: Header size = 0 Protocol = I2C, pktType = 0 */
        data = PROTOCOL_TYPE_I2C << PKT_HDR1_PROTOCOL_SHIFT;
        data |= packet_id << PKT_HDR1_PKT_ID_SHIFT;
        data |= i2c_bus->id << PKT_HDR1_CTLR_ID_SHIFT;
        writel(data, &i2c_bus->control->tx_fifo);
        debug("pkt header 1 sent (0x%x)\n", data);

        /* prepare header2 */
        data = (trans->num_bytes - 1) << PKT_HDR2_PAYLOAD_SIZE_SHIFT;
        writel(data, &i2c_bus->control->tx_fifo);
        debug("pkt header 2 sent (0x%x)\n", data);

        /* prepare IO specific header: configure the slave address */
        data = trans->address << PKT_HDR3_SLAVE_ADDR_SHIFT;

        /* Enable Read if it is not a write transaction */
        if (!(trans->flags & I2C_IS_WRITE))
                data |= PKT_HDR3_READ_MODE_MASK;
        if (end_with_repeated_start)
                data |= PKT_HDR3_REPEAT_START_MASK;

        /* Write I2C specific header */
        writel(data, &i2c_bus->control->tx_fifo);
        debug("pkt header 3 sent (0x%x)\n", data);
}

static int wait_for_tx_fifo_empty(struct i2c_control *control)
{
        u32 count;
        int timeout_us = I2C_TIMEOUT_USEC;

        while (timeout_us >= 0) {
                count = (readl(&control->fifo_status) & TX_FIFO_EMPTY_CNT_MASK)
                                >> TX_FIFO_EMPTY_CNT_SHIFT;
                if (count == I2C_FIFO_DEPTH)
                        return 1;
                udelay(10);
                timeout_us -= 10;
        }

        return 0;
}

static int wait_for_rx_fifo_notempty(struct i2c_control *control)
{
        u32 count;
        int timeout_us = I2C_TIMEOUT_USEC;

        while (timeout_us >= 0) {
                count = (readl(&control->fifo_status) & TX_FIFO_FULL_CNT_MASK)
                                >> TX_FIFO_FULL_CNT_SHIFT;
                if (count)
                        return 1;
                udelay(10);
                timeout_us -= 10;
        }

        return 0;
}

static int wait_for_transfer_complete(struct i2c_control *control)
{
        int int_status;
        int timeout_us = I2C_TIMEOUT_USEC;

        while (timeout_us >= 0) {
                int_status = readl(&control->int_status);
                if (int_status & I2C_INT_NO_ACK_MASK)
                        return -int_status;
                if (int_status & I2C_INT_ARBITRATION_LOST_MASK)
                        return -int_status;
                if (int_status & I2C_INT_XFER_COMPLETE_MASK)
                        return 0;

                udelay(10);
                timeout_us -= 10;
        }

        return -1;
}

static int send_recv_packets(struct i2c_bus *i2c_bus,
                             struct i2c_trans_info *trans)
{
        struct i2c_control *control = i2c_bus->control;
        u32 int_status;
        u32 words;
        u8 *dptr;
        u32 local;
        uchar last_bytes;
        int error = 0;
        int is_write = trans->flags & I2C_IS_WRITE;

        /* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */
        int_status = readl(&control->int_status);
        writel(int_status, &control->int_status);

        send_packet_headers(i2c_bus, trans, 1,
                            trans->flags & I2C_USE_REPEATED_START);

        words = DIV_ROUND_UP(trans->num_bytes, 4);
        last_bytes = trans->num_bytes & 3;
        dptr = trans->buf;

        while (words) {
                u32 *wptr = (u32 *)dptr;

                if (is_write) {
                        /* deal with word alignment */
                        if ((words == 1) && last_bytes) {
                                local = 0;
                                memcpy(&local, dptr, last_bytes);
                        } else if ((unsigned long)dptr & 3) {
                                memcpy(&local, dptr, sizeof(u32));
                        } else {
                                local = *wptr;
                        }
                        writel(local, &control->tx_fifo);
                        debug("pkt data sent (0x%x)\n", local);
                        if (!wait_for_tx_fifo_empty(control)) {
                                error = -1;
                                goto exit;
                        }
                } else {
                        if (!wait_for_rx_fifo_notempty(control)) {
                                error = -1;
                                goto exit;
                        }
                        /*
                         * for the last word, we read into our local buffer,
                         * in case that caller did not provide enough buffer.
                         */
                        local = readl(&control->rx_fifo);
                        if ((words == 1) && last_bytes)
                                memcpy(dptr, (char *)&local, last_bytes);
                        else if ((unsigned long)dptr & 3)
                                memcpy(dptr, &local, sizeof(u32));
                        else
                                *wptr = local;
                        debug("pkt data received (0x%x)\n", local);
                }
                words--;
                dptr += sizeof(u32);
        }

        if (wait_for_transfer_complete(control)) {
                error = -1;
                goto exit;
        }
        return 0;
exit:
        /* error, reset the controller. */
        i2c_reset_controller(i2c_bus);

        return error;
}

static int tegra_i2c_write_data(struct i2c_bus *i2c_bus, u32 addr, u8 *data,
                                u32 len, bool end_with_repeated_start)
{
        int error;
        struct i2c_trans_info trans_info;

        trans_info.address = addr;
        trans_info.buf = data;
        trans_info.flags = I2C_IS_WRITE;
        if (end_with_repeated_start)
                trans_info.flags |= I2C_USE_REPEATED_START;
        trans_info.num_bytes = len;
        trans_info.is_10bit_address = 0;

        error = send_recv_packets(i2c_bus, &trans_info);
        if (error)
                debug("tegra_i2c_write_data: Error (%d) !!!\n", error);

        return error;
}

static int tegra_i2c_read_data(struct i2c_bus *i2c_bus, u32 addr, u8 *data,
                               u32 len)
{
        int error;
        struct i2c_trans_info trans_info;

        trans_info.address = addr | 1;
        trans_info.buf = data;
        trans_info.flags = 0;
        trans_info.num_bytes = len;
        trans_info.is_10bit_address = 0;

        error = send_recv_packets(i2c_bus, &trans_info);
        if (error)
                debug("tegra_i2c_read_data: Error (%d) !!!\n", error);

        return error;
}

static int tegra_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
{
        struct i2c_bus *i2c_bus = dev_get_priv(dev);

        i2c_bus->speed = speed;
        i2c_init_controller(i2c_bus);

        return 0;
}

static int tegra_i2c_probe(struct udevice *dev)
{
        struct i2c_bus *i2c_bus = dev_get_priv(dev);
        int ret;
        bool is_dvc;

        i2c_bus->id = dev_seq(dev);
        i2c_bus->type = dev_get_driver_data(dev);
        i2c_bus->regs = (struct i2c_ctlr *)dev_read_addr(dev);
        if ((ulong)i2c_bus->regs == FDT_ADDR_T_NONE) {
                debug("%s: Cannot get regs address\n", __func__);
                return -EINVAL;
        }

        ret = reset_get_by_name(dev, "i2c", &i2c_bus->reset_ctl);
        if (ret) {
                pr_err("reset_get_by_name() failed: %d\n", ret);
                return ret;
        }
        ret = clk_get_by_name(dev, "div-clk", &i2c_bus->clk);
        if (ret) {
                pr_err("clk_get_by_name() failed: %d\n", ret);
                return ret;
        }

#ifndef CONFIG_TEGRA186
        /*
         * We don't have a binding for pinmux yet. Leave it out for now. So
         * far no one needs anything other than the default.
         */
        i2c_bus->pinmux_config = FUNCMUX_DEFAULT;

        /*
         * We can't specify the pinmux config in the fdt, so I2C2 will not
         * work on Seaboard. It normally has no devices on it anyway.
         * You could add in this little hack if you need to use it.
         * The correct solution is a pinmux binding in the fdt.
         *
         *      if (i2c_bus->clk.id == PERIPH_ID_I2C2)
         *              i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA;
         */
#endif

        is_dvc = dev_get_driver_data(dev) == TYPE_DVC;
        if (is_dvc) {
                i2c_bus->control =
                        &((struct dvc_ctlr *)i2c_bus->regs)->control;
        } else {
                i2c_bus->control = &i2c_bus->regs->control;
        }
        i2c_init_controller(i2c_bus);
        debug("%s: controller bus %d at %p, speed %d: ",
              is_dvc ? "dvc" : "i2c", dev_seq(dev), i2c_bus->regs,
              i2c_bus->speed);

        return 0;
}

/* i2c write version without the register address */
static int i2c_write_data(struct i2c_bus *i2c_bus, uchar chip, uchar *buffer,
                          int len, bool end_with_repeated_start)
{
        int rc;

        debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
        debug("write_data: ");
        /* use rc for counter */
        for (rc = 0; rc < len; ++rc)
                debug(" 0x%02x", buffer[rc]);
        debug("\n");

        /* Shift 7-bit address over for lower-level i2c functions */
        rc = tegra_i2c_write_data(i2c_bus, chip << 1, buffer, len,
                                  end_with_repeated_start);
        if (rc)
                debug("i2c_write_data(): rc=%d\n", rc);

        return rc;
}

/* i2c read version without the register address */
static int i2c_read_data(struct i2c_bus *i2c_bus, uchar chip, uchar *buffer,
                         int len)
{
        int rc;

        debug("inside i2c_read_data():\n");
        /* Shift 7-bit address over for lower-level i2c functions */
        rc = tegra_i2c_read_data(i2c_bus, chip << 1, buffer, len);
        if (rc) {
                debug("i2c_read_data(): rc=%d\n", rc);
                return rc;
        }

        debug("i2c_read_data: ");
        /* reuse rc for counter*/
        for (rc = 0; rc < len; ++rc)
                debug(" 0x%02x", buffer[rc]);
        debug("\n");

        return 0;
}

/* Probe to see if a chip is present. */
static int tegra_i2c_probe_chip(struct udevice *bus, uint chip_addr,
                                uint chip_flags)
{
        struct i2c_bus *i2c_bus = dev_get_priv(bus);
        int rc;
        u8 reg;

        /* Shift 7-bit address over for lower-level i2c functions */
        rc = tegra_i2c_write_data(i2c_bus, chip_addr << 1, &reg, sizeof(reg),
                                  false);

        return rc;
}

static int tegra_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
                          int nmsgs)
{
        struct i2c_bus *i2c_bus = dev_get_priv(bus);
        int ret;

        debug("i2c_xfer: %d messages\n", nmsgs);
        for (; nmsgs > 0; nmsgs--, msg++) {
                bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);

                debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
                if (msg->flags & I2C_M_RD) {
                        ret = i2c_read_data(i2c_bus, msg->addr, msg->buf,
                                            msg->len);
                } else {
                        ret = i2c_write_data(i2c_bus, msg->addr, msg->buf,
                                             msg->len, next_is_read);
                }
                if (ret) {
                        debug("i2c_write: error sending\n");
                        return -EREMOTEIO;
                }
        }

        return 0;
}

int tegra_i2c_get_dvc_bus(struct udevice **busp)
{
        return uclass_first_device_drvdata(UCLASS_I2C, TYPE_DVC, busp);
}

static const struct dm_i2c_ops tegra_i2c_ops = {
        .xfer           = tegra_i2c_xfer,
        .probe_chip     = tegra_i2c_probe_chip,
        .set_bus_speed  = tegra_i2c_set_bus_speed,
};

static const struct udevice_id tegra_i2c_ids[] = {
        { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
        { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
        { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
        { }
};

U_BOOT_DRIVER(i2c_tegra) = {
        .name   = "i2c_tegra",
        .id     = UCLASS_I2C,
        .of_match = tegra_i2c_ids,
        .probe  = tegra_i2c_probe,
        .priv_auto      = sizeof(struct i2c_bus),
        .ops    = &tegra_i2c_ops,
};