/*
 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 * Copyright (c) 2010-2011 NVIDIA Corporation
 *  NVIDIA Corporation <www.nvidia.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <fdtdec.h>
#include <i2c.h>
#include <asm/io.h>
#include <asm/arch/clk_rst.h>
#include <asm/arch/clock.h>
#include <asm/arch/funcmux.h>
#include <asm/arch/gpio.h>
#include <asm/arch/pinmux.h>
#include <asm/arch/tegra_i2c.h>

DECLARE_GLOBAL_DATA_PTR;

static unsigned int i2c_bus_num;

/* Information about i2c controller */
struct i2c_bus {
        int                     id;
        enum periph_id          periph_id;
        int                     speed;
        int                     pinmux_config;
        struct i2c_control      *control;
        struct i2c_ctlr         *regs;
        int                     is_dvc; /* DVC type, rather than I2C */
        int                     inited; /* bus is inited */
};

static struct i2c_bus i2c_controllers[TEGRA_I2C_NUM_CONTROLLERS];

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->is_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_periph(i2c_bus->periph_id, 1);

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

static void i2c_init_controller(struct i2c_bus *i2c_bus)
{
        /*
         * 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.
         */
        clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
                               i2c_bus->speed * 2 * 8);

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

        /* Configure I2C controller. */
        if (i2c_bus->is_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);
        }

        funcmux_select(i2c_bus->periph_id, i2c_bus->pinmux_config);
}

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

        /* 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);

        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 ((unsigned)dptr & 3) {
                                memcpy(&local, dptr, sizeof(u32));
                                writel(local, &control->tx_fifo);
                                debug("pkt data sent (0x%x)\n", local);
                        } else {
                                writel(*wptr, &control->tx_fifo);
                                debug("pkt data sent (0x%x)\n", *wptr);
                        }
                        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)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 tegra2_i2c_write_data(u32 addr, u8 *data, u32 len)
{
        int error;
        struct i2c_trans_info trans_info;

        trans_info.address = addr;
        trans_info.buf = data;
        trans_info.flags = I2C_IS_WRITE;
        trans_info.num_bytes = len;
        trans_info.is_10bit_address = 0;

        error = send_recv_packets(&i2c_controllers[i2c_bus_num], &trans_info);
        if (error)
                debug("tegra2_i2c_write_data: Error (%d) !!!\n", error);

        return error;
}

static int tegra2_i2c_read_data(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_controllers[i2c_bus_num], &trans_info);
        if (error)
                debug("tegra2_i2c_read_data: Error (%d) !!!\n", error);

        return error;
}

#ifndef CONFIG_OF_CONTROL
#error "Please enable device tree support to use this driver"
#endif

unsigned int i2c_get_bus_speed(void)
{
        return i2c_controllers[i2c_bus_num].speed;
}

int i2c_set_bus_speed(unsigned int speed)
{
        struct i2c_bus *i2c_bus;

        i2c_bus = &i2c_controllers[i2c_bus_num];
        i2c_bus->speed = speed;
        i2c_init_controller(i2c_bus);

        return 0;
}

static int i2c_get_config(const void *blob, int node, struct i2c_bus *i2c_bus)
{
        i2c_bus->regs = (struct i2c_ctlr *)fdtdec_get_addr(blob, node, "reg");

        /*
         * 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;
        i2c_bus->speed = fdtdec_get_int(blob, node, "clock-frequency", 0);
        i2c_bus->periph_id = clock_decode_periph_id(blob, node);

        /*
         * 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->periph_id == PERIPH_ID_I2C2)
         *              i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA;
         */
        if (i2c_bus->periph_id == -1)
                return -FDT_ERR_NOTFOUND;

        return 0;
}

/*
 * Process a list of nodes, adding them to our list of I2C ports.
 *
 * @param blob          fdt blob
 * @param node_list     list of nodes to process (any <=0 are ignored)
 * @param count         number of nodes to process
 * @param is_dvc        1 if these are DVC ports, 0 if standard I2C
 * @return 0 if ok, -1 on error
 */
static int process_nodes(const void *blob, int node_list[], int count,
                         int is_dvc)
{
        struct i2c_bus *i2c_bus;
        int i;

        /* build the i2c_controllers[] for each controller */
        for (i = 0; i < count; i++) {
                int node = node_list[i];

                if (node <= 0)
                        continue;

                i2c_bus = &i2c_controllers[i];
                i2c_bus->id = i;

                if (i2c_get_config(blob, node, i2c_bus)) {
                        printf("i2c_init_board: failed to decode bus %d\n", i);
                        return -1;
                }

                i2c_bus->is_dvc = is_dvc;
                if (is_dvc) {
                        i2c_bus->control =
                                &((struct dvc_ctlr *)i2c_bus->regs)->control;
                } else {
                        i2c_bus->control = &i2c_bus->regs->control;
                }
                debug("%s: controller bus %d at %p, periph_id %d, speed %d: ",
                      is_dvc ? "dvc" : "i2c", i, i2c_bus->regs,
                      i2c_bus->periph_id, i2c_bus->speed);
                i2c_init_controller(i2c_bus);
                debug("ok\n");
                i2c_bus->inited = 1;

                /* Mark position as used */
                node_list[i] = -1;
        }

        return 0;
}

/* Sadly there is no error return from this function */
void i2c_init_board(void)
{
        int node_list[TEGRA_I2C_NUM_CONTROLLERS];
        const void *blob = gd->fdt_blob;
        int count;

        /* First get the normal i2c ports */
        count = fdtdec_find_aliases_for_id(blob, "i2c",
                        COMPAT_NVIDIA_TEGRA20_I2C, node_list,
                        TEGRA_I2C_NUM_CONTROLLERS);
        if (process_nodes(blob, node_list, count, 0))
                return;

        /* Now look for dvc ports */
        count = fdtdec_add_aliases_for_id(blob, "i2c",
                        COMPAT_NVIDIA_TEGRA20_DVC, node_list,
                        TEGRA_I2C_NUM_CONTROLLERS);
        if (process_nodes(blob, node_list, count, 1))
                return;
}

void i2c_init(int speed, int slaveaddr)
{
        /* This will override the speed selected in the fdt for that port */
        debug("i2c_init(speed=%u, slaveaddr=0x%x)\n", speed, slaveaddr);
        i2c_set_bus_speed(speed);
}

/* i2c write version without the register address */
int i2c_write_data(uchar chip, uchar *buffer, int len)
{
        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 = tegra2_i2c_write_data(chip << 1, buffer, len);
        if (rc)
                debug("i2c_write_data(): rc=%d\n", rc);

        return rc;
}

/* i2c read version without the register address */
int i2c_read_data(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 = tegra2_i2c_read_data(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. */
int i2c_probe(uchar chip)
{
        int rc;
        uchar reg;

        debug("i2c_probe: addr=0x%x\n", chip);
        reg = 0;
        rc = i2c_write_data(chip, &reg, 1);
        if (rc) {
                debug("Error probing 0x%x.\n", chip);
                return 1;
        }
        return 0;
}

static int i2c_addr_ok(const uint addr, const int alen)
{
        /* We support 7 or 10 bit addresses, so one or two bytes each */
        return alen == 1 || alen == 2;
}

/* Read bytes */
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
        uint offset;
        int i;

        debug("i2c_read: chip=0x%x, addr=0x%x, len=0x%x\n",
                                chip, addr, len);
        if (!i2c_addr_ok(addr, alen)) {
                debug("i2c_read: Bad address %x.%d.\n", addr, alen);
                return 1;
        }
        for (offset = 0; offset < len; offset++) {
                if (alen) {
                        uchar data[alen];
                        for (i = 0; i < alen; i++) {
                                data[alen - i - 1] =
                                        (addr + offset) >> (8 * i);
                        }
                        if (i2c_write_data(chip, data, alen)) {
                                debug("i2c_read: error sending (0x%x)\n",
                                        addr);
                                return 1;
                        }
                }
                if (i2c_read_data(chip, buffer + offset, 1)) {
                        debug("i2c_read: error reading (0x%x)\n", addr);
                        return 1;
                }
        }

        return 0;
}

/* Write bytes */
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
        uint offset;
        int i;

        debug("i2c_write: chip=0x%x, addr=0x%x, len=0x%x\n",
                                chip, addr, len);
        if (!i2c_addr_ok(addr, alen)) {
                debug("i2c_write: Bad address %x.%d.\n", addr, alen);
                return 1;
        }
        for (offset = 0; offset < len; offset++) {
                uchar data[alen + 1];
                for (i = 0; i < alen; i++)
                        data[alen - i - 1] = (addr + offset) >> (8 * i);
                data[alen] = buffer[offset];
                if (i2c_write_data(chip, data, alen + 1)) {
                        debug("i2c_write: error sending (0x%x)\n", addr);
                        return 1;
                }
        }

        return 0;
}

#if defined(CONFIG_I2C_MULTI_BUS)
/*
 * Functions for multiple I2C bus handling
 */
unsigned int i2c_get_bus_num(void)
{
        return i2c_bus_num;
}

int i2c_set_bus_num(unsigned int bus)
{
        if (bus >= TEGRA_I2C_NUM_CONTROLLERS || !i2c_controllers[bus].inited)
                return -1;
        i2c_bus_num = bus;

        return 0;
}
#endif

int tegra_i2c_get_dvc_bus_num(void)
{
        int i;

        for (i = 0; i < CONFIG_SYS_MAX_I2C_BUS; i++) {
                struct i2c_bus *bus = &i2c_controllers[i];

                if (bus->inited && bus->is_dvc)
                        return i;
        }

        return -1;
}