/*
 * Copyright 2006,2009 Freescale Semiconductor, Inc.
 *
 * 2012, Heiko Schocher, DENX Software Engineering, hs@denx.de.
 * Changes for multibus/multiadapter I2C support.
 *
 * SPDX-License-Identifier:     GPL-2.0
 */

#include <common.h>
#include <command.h>
#include <i2c.h>                /* Functional interface */
#include <asm/io.h>
#include <asm/fsl_i2c.h>        /* HW definitions */
#include <dm.h>
#include <mapmem.h>

/* The maximum number of microseconds we will wait until another master has
 * released the bus.  If not defined in the board header file, then use a
 * generic value.
 */
#ifndef CONFIG_I2C_MBB_TIMEOUT
#define CONFIG_I2C_MBB_TIMEOUT  100000
#endif

/* The maximum number of microseconds we will wait for a read or write
 * operation to complete.  If not defined in the board header file, then use a
 * generic value.
 */
#ifndef CONFIG_I2C_TIMEOUT
#define CONFIG_I2C_TIMEOUT      100000
#endif

#define I2C_READ_BIT  1
#define I2C_WRITE_BIT 0

DECLARE_GLOBAL_DATA_PTR;

#ifndef CONFIG_DM_I2C
static const struct fsl_i2c_base *i2c_base[4] = {
        (struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C_OFFSET),
#ifdef CONFIG_SYS_FSL_I2C2_OFFSET
        (struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C2_OFFSET),
#endif
#ifdef CONFIG_SYS_FSL_I2C3_OFFSET
        (struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C3_OFFSET),
#endif
#ifdef CONFIG_SYS_FSL_I2C4_OFFSET
        (struct fsl_i2c_base *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C4_OFFSET)
#endif
};
#endif

/* I2C speed map for a DFSR value of 1 */

#ifdef __M68K__
/*
 * Map I2C frequency dividers to FDR and DFSR values
 *
 * This structure is used to define the elements of a table that maps I2C
 * frequency divider (I2C clock rate divided by I2C bus speed) to a value to be
 * programmed into the Frequency Divider Ratio (FDR) and Digital Filter
 * Sampling Rate (DFSR) registers.
 *
 * The actual table should be defined in the board file, and it must be called
 * fsl_i2c_speed_map[].
 *
 * The last entry of the table must have a value of {-1, X}, where X is same
 * FDR/DFSR values as the second-to-last entry.  This guarantees that any
 * search through the array will always find a match.
 *
 * The values of the divider must be in increasing numerical order, i.e.
 * fsl_i2c_speed_map[x+1].divider > fsl_i2c_speed_map[x].divider.
 *
 * For this table, the values are based on a value of 1 for the DFSR
 * register.  See the application note AN2919 "Determining the I2C Frequency
 * Divider Ratio for SCL"
 *
 * ColdFire I2C frequency dividers for FDR values are different from
 * PowerPC. The protocol to use the I2C module is still the same.
 * A different table is defined and are based on MCF5xxx user manual.
 *
 */
static const struct {
        unsigned short divider;
        u8 fdr;
} fsl_i2c_speed_map[] = {
        {20, 32}, {22, 33}, {24, 34}, {26, 35},
        {28, 0}, {28, 36}, {30, 1}, {32, 37},
        {34, 2}, {36, 38}, {40, 3}, {40, 39},
        {44, 4}, {48, 5}, {48, 40}, {56, 6},
        {56, 41}, {64, 42}, {68, 7}, {72, 43},
        {80, 8}, {80, 44}, {88, 9}, {96, 41},
        {104, 10}, {112, 42}, {128, 11}, {128, 43},
        {144, 12}, {160, 13}, {160, 48}, {192, 14},
        {192, 49}, {224, 50}, {240, 15}, {256, 51},
        {288, 16}, {320, 17}, {320, 52}, {384, 18},
        {384, 53}, {448, 54}, {480, 19}, {512, 55},
        {576, 20}, {640, 21}, {640, 56}, {768, 22},
        {768, 57}, {960, 23}, {896, 58}, {1024, 59},
        {1152, 24}, {1280, 25}, {1280, 60}, {1536, 26},
        {1536, 61}, {1792, 62}, {1920, 27}, {2048, 63},
        {2304, 28}, {2560, 29}, {3072, 30}, {3840, 31},
        {-1, 31}
};
#endif

/**
 * Set the I2C bus speed for a given I2C device
 *
 * @param base: the I2C device registers
 * @i2c_clk: I2C bus clock frequency
 * @speed: the desired speed of the bus
 *
 * The I2C device must be stopped before calling this function.
 *
 * The return value is the actual bus speed that is set.
 */
static unsigned int set_i2c_bus_speed(const struct fsl_i2c_base *base,
        unsigned int i2c_clk, unsigned int speed)
{
        unsigned short divider = min(i2c_clk / speed, (unsigned int)USHRT_MAX);

        /*
         * We want to choose an FDR/DFSR that generates an I2C bus speed that
         * is equal to or lower than the requested speed.  That means that we
         * want the first divider that is equal to or greater than the
         * calculated divider.
         */
#ifdef __PPC__
        u8 dfsr, fdr = 0x31; /* Default if no FDR found */
        /* a, b and dfsr matches identifiers A,B and C respectively in AN2919 */
        unsigned short a, b, ga, gb;
        unsigned long c_div, est_div;

#ifdef CONFIG_FSL_I2C_CUSTOM_DFSR
        dfsr = CONFIG_FSL_I2C_CUSTOM_DFSR;
#else
        /* Condition 1: dfsr <= 50/T */
        dfsr = (5 * (i2c_clk / 1000)) / 100000;
#endif
#ifdef CONFIG_FSL_I2C_CUSTOM_FDR
        fdr = CONFIG_FSL_I2C_CUSTOM_FDR;
        speed = i2c_clk / divider; /* Fake something */
#else
        debug("Requested speed:%d, i2c_clk:%d\n", speed, i2c_clk);
        if (!dfsr)
                dfsr = 1;

        est_div = ~0;
        for (ga = 0x4, a = 10; a <= 30; ga++, a += 2) {
                for (gb = 0; gb < 8; gb++) {
                        b = 16 << gb;
                        c_div = b * (a + ((3*dfsr)/b)*2);
                        if ((c_div > divider) && (c_div < est_div)) {
                                unsigned short bin_gb, bin_ga;

                                est_div = c_div;
                                bin_gb = gb << 2;
                                bin_ga = (ga & 0x3) | ((ga & 0x4) << 3);
                                fdr = bin_gb | bin_ga;
                                speed = i2c_clk / est_div;
                                debug("FDR:0x%.2x, div:%ld, ga:0x%x, gb:0x%x, "
                                      "a:%d, b:%d, speed:%d\n",
                                      fdr, est_div, ga, gb, a, b, speed);
                                /* Condition 2 not accounted for */
                                debug("Tr <= %d ns\n",
                                      (b - 3 * dfsr) * 1000000 /
                                      (i2c_clk / 1000));
                        }
                }
                if (a == 20)
                        a += 2;
                if (a == 24)
                        a += 4;
        }
        debug("divider:%d, est_div:%ld, DFSR:%d\n", divider, est_div, dfsr);
        debug("FDR:0x%.2x, speed:%d\n", fdr, speed);
#endif
        writeb(dfsr, &base->dfsrr);     /* set default filter */
        writeb(fdr, &base->fdr);        /* set bus speed */
#else
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(fsl_i2c_speed_map); i++)
                if (fsl_i2c_speed_map[i].divider >= divider) {
                        u8 fdr;

                        fdr = fsl_i2c_speed_map[i].fdr;
                        speed = i2c_clk / fsl_i2c_speed_map[i].divider;
                        writeb(fdr, &base->fdr);        /* set bus speed */

                        break;
                }
#endif
        return speed;
}

#ifndef CONFIG_DM_I2C
static unsigned int get_i2c_clock(int bus)
{
        if (bus)
                return gd->arch.i2c2_clk;       /* I2C2 clock */
        else
                return gd->arch.i2c1_clk;       /* I2C1 clock */
}
#endif

static int fsl_i2c_fixup(const struct fsl_i2c_base *base)
{
        const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
        unsigned long long timeval = 0;
        int ret = -1;
        unsigned int flags = 0;

#ifdef CONFIG_SYS_FSL_ERRATUM_I2C_A004447
        unsigned int svr = get_svr();
        if ((SVR_SOC_VER(svr) == SVR_8548 && IS_SVR_REV(svr, 3, 1)) ||
            (SVR_REV(svr) <= CONFIG_SYS_FSL_A004447_SVR_REV))
                flags = I2C_CR_BIT6;
#endif

        writeb(I2C_CR_MEN | I2C_CR_MSTA, &base->cr);

        timeval = get_ticks();
        while (!(readb(&base->sr) & I2C_SR_MBB)) {
                if ((get_ticks() - timeval) > timeout)
                        goto err;
        }

        if (readb(&base->sr) & I2C_SR_MAL) {
                /* SDA is stuck low */
                writeb(0, &base->cr);
                udelay(100);
                writeb(I2C_CR_MSTA | flags, &base->cr);
                writeb(I2C_CR_MEN | I2C_CR_MSTA | flags, &base->cr);
        }

        readb(&base->dr);

        timeval = get_ticks();
        while (!(readb(&base->sr) & I2C_SR_MIF)) {
                if ((get_ticks() - timeval) > timeout)
                        goto err;
        }
        ret = 0;

err:
        writeb(I2C_CR_MEN | flags, &base->cr);
        writeb(0, &base->sr);
        udelay(100);

        return ret;
}

static void __i2c_init(const struct fsl_i2c_base *base, int speed, int
                       slaveadd, int i2c_clk, int busnum)
{
        const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
        unsigned long long timeval;

#ifdef CONFIG_SYS_I2C_INIT_BOARD
        /* Call board specific i2c bus reset routine before accessing the
         * environment, which might be in a chip on that bus. For details
         * about this problem see doc/I2C_Edge_Conditions.
        */
        i2c_init_board();
#endif
        writeb(0, &base->cr);           /* stop I2C controller */
        udelay(5);                      /* let it shutdown in peace */
        set_i2c_bus_speed(base, i2c_clk, speed);
        writeb(slaveadd << 1, &base->adr);/* write slave address */
        writeb(0x0, &base->sr);         /* clear status register */
        writeb(I2C_CR_MEN, &base->cr);  /* start I2C controller */

        timeval = get_ticks();
        while (readb(&base->sr) & I2C_SR_MBB) {
                if ((get_ticks() - timeval) < timeout)
                        continue;

                if (fsl_i2c_fixup(base))
                        debug("i2c_init: BUS#%d failed to init\n",
                              busnum);

                break;
        }
}

static int
i2c_wait4bus(const struct fsl_i2c_base *base)
{
        unsigned long long timeval = get_ticks();
        const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);

        while (readb(&base->sr) & I2C_SR_MBB) {
                if ((get_ticks() - timeval) > timeout)
                        return -1;
        }

        return 0;
}

static inline int
i2c_wait(const struct fsl_i2c_base *base, int write)
{
        u32 csr;
        unsigned long long timeval = get_ticks();
        const unsigned long long timeout = usec2ticks(CONFIG_I2C_TIMEOUT);

        do {
                csr = readb(&base->sr);
                if (!(csr & I2C_SR_MIF))
                        continue;
                /* Read again to allow register to stabilise */
                csr = readb(&base->sr);

                writeb(0x0, &base->sr);

                if (csr & I2C_SR_MAL) {
                        debug("i2c_wait: MAL\n");
                        return -1;
                }

                if (!(csr & I2C_SR_MCF))        {
                        debug("i2c_wait: unfinished\n");
                        return -1;
                }

                if (write == I2C_WRITE_BIT && (csr & I2C_SR_RXAK)) {
                        debug("i2c_wait: No RXACK\n");
                        return -1;
                }

                return 0;
        } while ((get_ticks() - timeval) < timeout);

        debug("i2c_wait: timed out\n");
        return -1;
}

static inline int
i2c_write_addr(const struct fsl_i2c_base *base, u8 dev, u8 dir, int rsta)
{
        writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX
               | (rsta ? I2C_CR_RSTA : 0),
               &base->cr);

        writeb((dev << 1) | dir, &base->dr);

        if (i2c_wait(base, I2C_WRITE_BIT) < 0)
                return 0;

        return 1;
}

static inline int
__i2c_write_data(const struct fsl_i2c_base *base, u8 *data, int length)
{
        int i;

        for (i = 0; i < length; i++) {
                writeb(data[i], &base->dr);

                if (i2c_wait(base, I2C_WRITE_BIT) < 0)
                        break;
        }

        return i;
}

static inline int
__i2c_read_data(const struct fsl_i2c_base *base, u8 *data, int length)
{
        int i;

        writeb(I2C_CR_MEN | I2C_CR_MSTA | ((length == 1) ? I2C_CR_TXAK : 0),
               &base->cr);

        /* dummy read */
        readb(&base->dr);

        for (i = 0; i < length; i++) {
                if (i2c_wait(base, I2C_READ_BIT) < 0)
                        break;

                /* Generate ack on last next to last byte */
                if (i == length - 2)
                        writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_TXAK,
                               &base->cr);

                /* Do not generate stop on last byte */
                if (i == length - 1)
                        writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX,
                               &base->cr);

                data[i] = readb(&base->dr);
        }

        return i;
}

static int
__i2c_read(const struct fsl_i2c_base *base, u8 chip_addr, u8 *offset, int olen,
           u8 *data, int dlen)
{
        int ret = -1; /* signal error */

        if (i2c_wait4bus(base) < 0)
                return -1;

        /* Some drivers use offset lengths in excess of 4 bytes. These drivers
         * adhere to the following convention:
         * - the offset length is passed as negative (that is, the absolute
         *   value of olen is the actual offset length)
         * - the offset itself is passed in data, which is overwritten by the
         *   subsequent read operation
         */
        if (olen < 0) {
                if (i2c_write_addr(base, chip_addr, I2C_WRITE_BIT, 0) != 0)
                        ret = __i2c_write_data(base, data, -olen);

                if (ret != -olen)
                        return -1;

                if (dlen && i2c_write_addr(base, chip_addr,
                                           I2C_READ_BIT, 1) != 0)
                        ret = __i2c_read_data(base, data, dlen);
        } else {
                if ((!dlen || olen > 0) &&
                    i2c_write_addr(base, chip_addr, I2C_WRITE_BIT, 0) != 0  &&
                    __i2c_write_data(base, offset, olen) == olen)
                        ret = 0; /* No error so far */

                if (dlen && i2c_write_addr(base, chip_addr, I2C_READ_BIT,
                                           olen ? 1 : 0) != 0)
                        ret = __i2c_read_data(base, data, dlen);
        }

        writeb(I2C_CR_MEN, &base->cr);

        if (i2c_wait4bus(base)) /* Wait until STOP */
                debug("i2c_read: wait4bus timed out\n");

        if (ret == dlen)
                return 0;

        return -1;
}

static int
__i2c_write(const struct fsl_i2c_base *base, u8 chip_addr, u8 *offset, int olen,
            u8 *data, int dlen)
{
        int ret = -1; /* signal error */

        if (i2c_wait4bus(base) < 0)
                return -1;

        if (i2c_write_addr(base, chip_addr, I2C_WRITE_BIT, 0) != 0 &&
            __i2c_write_data(base, offset, olen) == olen) {
                ret = __i2c_write_data(base, data, dlen);
        }

        writeb(I2C_CR_MEN, &base->cr);
        if (i2c_wait4bus(base)) /* Wait until STOP */
                debug("i2c_write: wait4bus timed out\n");

        if (ret == dlen)
                return 0;

        return -1;
}

static int
__i2c_probe_chip(const struct fsl_i2c_base *base, uchar chip)
{
        /* For unknow reason the controller will ACK when
         * probing for a slave with the same address, so skip
         * it.
         */
        if (chip == (readb(&base->adr) >> 1))
                return -1;

        return __i2c_read(base, chip, 0, 0, NULL, 0);
}

static unsigned int __i2c_set_bus_speed(const struct fsl_i2c_base *base,
                        unsigned int speed, int i2c_clk)
{
        writeb(0, &base->cr);           /* stop controller */
        set_i2c_bus_speed(base, i2c_clk, speed);
        writeb(I2C_CR_MEN, &base->cr);  /* start controller */

        return 0;
}

#ifndef CONFIG_DM_I2C
static void fsl_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
{
        __i2c_init(i2c_base[adap->hwadapnr], speed, slaveadd,
                   get_i2c_clock(adap->hwadapnr), adap->hwadapnr);
}

static int
fsl_i2c_probe_chip(struct i2c_adapter *adap, uchar chip)
{
        return __i2c_probe_chip(i2c_base[adap->hwadapnr], chip);
}

static int
fsl_i2c_read(struct i2c_adapter *adap, u8 chip_addr, uint offset, int olen,
             u8 *data, int dlen)
{
        u8 *o = (u8 *)&offset;
        return __i2c_read(i2c_base[adap->hwadapnr], chip_addr, &o[4 - olen],
                          olen, data, dlen);
}

static int
fsl_i2c_write(struct i2c_adapter *adap, u8 chip_addr, uint offset, int olen,
              u8 *data, int dlen)
{
        u8 *o = (u8 *)&offset;
        return __i2c_write(i2c_base[adap->hwadapnr], chip_addr, &o[4 - olen],
                           olen, data, dlen);
}

static unsigned int fsl_i2c_set_bus_speed(struct i2c_adapter *adap,
                                          unsigned int speed)
{
        return __i2c_set_bus_speed(i2c_base[adap->hwadapnr], speed,
                                   get_i2c_clock(adap->hwadapnr));
}

/*
 * Register fsl i2c adapters
 */
U_BOOT_I2C_ADAP_COMPLETE(fsl_0, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
                         fsl_i2c_write, fsl_i2c_set_bus_speed,
                         CONFIG_SYS_FSL_I2C_SPEED, CONFIG_SYS_FSL_I2C_SLAVE,
                         0)
#ifdef CONFIG_SYS_FSL_I2C2_OFFSET
U_BOOT_I2C_ADAP_COMPLETE(fsl_1, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
                         fsl_i2c_write, fsl_i2c_set_bus_speed,
                         CONFIG_SYS_FSL_I2C2_SPEED, CONFIG_SYS_FSL_I2C2_SLAVE,
                         1)
#endif
#ifdef CONFIG_SYS_FSL_I2C3_OFFSET
U_BOOT_I2C_ADAP_COMPLETE(fsl_2, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
                         fsl_i2c_write, fsl_i2c_set_bus_speed,
                         CONFIG_SYS_FSL_I2C3_SPEED, CONFIG_SYS_FSL_I2C3_SLAVE,
                         2)
#endif
#ifdef CONFIG_SYS_FSL_I2C4_OFFSET
U_BOOT_I2C_ADAP_COMPLETE(fsl_3, fsl_i2c_init, fsl_i2c_probe_chip, fsl_i2c_read,
                         fsl_i2c_write, fsl_i2c_set_bus_speed,
                         CONFIG_SYS_FSL_I2C4_SPEED, CONFIG_SYS_FSL_I2C4_SLAVE,
                         3)
#endif
#else /* CONFIG_DM_I2C */
static int fsl_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
                              u32 chip_flags)
{
        struct fsl_i2c_dev *dev = dev_get_priv(bus);
        return __i2c_probe_chip(dev->base, chip_addr);
}

static int fsl_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
        struct fsl_i2c_dev *dev = dev_get_priv(bus);
        return __i2c_set_bus_speed(dev->base, speed, dev->i2c_clk);
}

static int fsl_i2c_ofdata_to_platdata(struct udevice *bus)
{
        struct fsl_i2c_dev *dev = dev_get_priv(bus);
        fdt_addr_t addr;
        fdt_size_t size;
        int node = dev_of_offset(bus);

        addr = fdtdec_get_addr_size_auto_noparent(gd->fdt_blob, node, "reg", 0,
                                                  &size, false);

        dev->base = map_sysmem(CONFIG_SYS_IMMR + addr, size);

        if (!dev->base)
                return -ENOMEM;

        dev->index = fdtdec_get_int(gd->fdt_blob, node, "cell-index", -1);
        dev->slaveadd = fdtdec_get_int(gd->fdt_blob, node,
                                       "u-boot,i2c-slave-addr", 0x7f);
        dev->speed = fdtdec_get_int(gd->fdt_blob, node, "clock-frequency",
                                    400000);

        dev->i2c_clk = dev->index ? gd->arch.i2c2_clk : gd->arch.i2c1_clk;

        return 0;
}

static int fsl_i2c_probe(struct udevice *bus)
{
        struct fsl_i2c_dev *dev = dev_get_priv(bus);
        __i2c_init(dev->base, dev->speed, dev->slaveadd, dev->i2c_clk,
                   dev->index);
        return 0;
}

static int fsl_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
        struct fsl_i2c_dev *dev = dev_get_priv(bus);
        struct i2c_msg *dmsg, *omsg, dummy;

        memset(&dummy, 0, sizeof(struct i2c_msg));

        /* We expect either two messages (one with an offset and one with the
         * actucal data) or one message (just data) */
        if (nmsgs > 2 || nmsgs == 0) {
                debug("%s: Only one or two messages are supported.", __func__);
                return -1;
        }

        omsg = nmsgs == 1 ? &dummy : msg;
        dmsg = nmsgs == 1 ? msg : msg + 1;

        if (dmsg->flags & I2C_M_RD)
                return __i2c_read(dev->base, dmsg->addr, omsg->buf, omsg->len,
                                  dmsg->buf, dmsg->len);
        else
                return __i2c_write(dev->base, dmsg->addr, omsg->buf, omsg->len,
                                   dmsg->buf, dmsg->len);
}

static const struct dm_i2c_ops fsl_i2c_ops = {
        .xfer           = fsl_i2c_xfer,
        .probe_chip     = fsl_i2c_probe_chip,
        .set_bus_speed  = fsl_i2c_set_bus_speed,
};

static const struct udevice_id fsl_i2c_ids[] = {
        { .compatible = "fsl-i2c", },
        { /* sentinel */ }
};

U_BOOT_DRIVER(i2c_fsl) = {
        .name = "i2c_fsl",
        .id = UCLASS_I2C,
        .of_match = fsl_i2c_ids,
        .probe = fsl_i2c_probe,
        .ofdata_to_platdata = fsl_i2c_ofdata_to_platdata,
        .priv_auto_alloc_size = sizeof(struct fsl_i2c_dev),
        .ops = &fsl_i2c_ops,
};

#endif /* CONFIG_DM_I2C */