/****************************************************************************
 * Driver for Solarflare network controllers and boards
 * Copyright 2006-2012 Solarflare Communications Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation, incorporated herein by reference.
 */
/*
 * Driver for AMCC QT202x SFP+ and XFP adapters; see www.amcc.com for details
 */

#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include "efx.h"
#include "mdio_10g.h"
#include "phy.h"
#include "nic.h"

#define QT202X_REQUIRED_DEVS (MDIO_DEVS_PCS |           \
                              MDIO_DEVS_PMAPMD |        \
                              MDIO_DEVS_PHYXS)

#define QT202X_LOOPBACKS ((1 << LOOPBACK_PCS) |         \
                          (1 << LOOPBACK_PMAPMD) |      \
                          (1 << LOOPBACK_PHYXS_WS))

/****************************************************************************/
/* Quake-specific MDIO registers */
#define MDIO_QUAKE_LED0_REG     (0xD006)

/* QT2025C only */
#define PCS_FW_HEARTBEAT_REG    0xd7ee
#define PCS_FW_HEARTB_LBN       0
#define PCS_FW_HEARTB_WIDTH     8
#define PCS_FW_PRODUCT_CODE_1   0xd7f0
#define PCS_FW_VERSION_1        0xd7f3
#define PCS_FW_BUILD_1          0xd7f6
#define PCS_UC8051_STATUS_REG   0xd7fd
#define PCS_UC_STATUS_LBN       0
#define PCS_UC_STATUS_WIDTH     8
#define PCS_UC_STATUS_FW_SAVE   0x20
#define PMA_PMD_MODE_REG        0xc301
#define PMA_PMD_RXIN_SEL_LBN    6
#define PMA_PMD_FTX_CTRL2_REG   0xc309
#define PMA_PMD_FTX_STATIC_LBN  13
#define PMA_PMD_VEND1_REG       0xc001
#define PMA_PMD_VEND1_LBTXD_LBN 15
#define PCS_VEND1_REG           0xc000
#define PCS_VEND1_LBTXD_LBN     5

void falcon_qt202x_set_led(struct efx_nic *p, int led, int mode)
{
        int addr = MDIO_QUAKE_LED0_REG + led;
        efx_mdio_write(p, MDIO_MMD_PMAPMD, addr, mode);
}

struct qt202x_phy_data {
        enum efx_phy_mode phy_mode;
        bool bug17190_in_bad_state;
        unsigned long bug17190_timer;
        u32 firmware_ver;
};

#define QT2022C2_MAX_RESET_TIME 500
#define QT2022C2_RESET_WAIT 10

#define QT2025C_MAX_HEARTB_TIME (5 * HZ)
#define QT2025C_HEARTB_WAIT 100
#define QT2025C_MAX_FWSTART_TIME (25 * HZ / 10)
#define QT2025C_FWSTART_WAIT 100

#define BUG17190_INTERVAL (2 * HZ)

static int qt2025c_wait_heartbeat(struct efx_nic *efx)
{
        unsigned long timeout = jiffies + QT2025C_MAX_HEARTB_TIME;
        int reg, old_counter = 0;

        /* Wait for firmware heartbeat to start */
        for (;;) {
                int counter;
                reg = efx_mdio_read(efx, MDIO_MMD_PCS, PCS_FW_HEARTBEAT_REG);
                if (reg < 0)
                        return reg;
                counter = ((reg >> PCS_FW_HEARTB_LBN) &
                            ((1 << PCS_FW_HEARTB_WIDTH) - 1));
                if (old_counter == 0)
                        old_counter = counter;
                else if (counter != old_counter)
                        break;
                if (time_after(jiffies, timeout)) {
                        /* Some cables have EEPROMs that conflict with the
                         * PHY's on-board EEPROM so it cannot load firmware */
                        netif_err(efx, hw, efx->net_dev,
                                  "If an SFP+ direct attach cable is"
                                  " connected, please check that it complies"
                                  " with the SFP+ specification\n");
                        return -ETIMEDOUT;
                }
                msleep(QT2025C_HEARTB_WAIT);
        }

        return 0;
}

static int qt2025c_wait_fw_status_good(struct efx_nic *efx)
{
        unsigned long timeout = jiffies + QT2025C_MAX_FWSTART_TIME;
        int reg;

        /* Wait for firmware status to look good */
        for (;;) {
                reg = efx_mdio_read(efx, MDIO_MMD_PCS, PCS_UC8051_STATUS_REG);
                if (reg < 0)
                        return reg;
                if ((reg &
                     ((1 << PCS_UC_STATUS_WIDTH) - 1) << PCS_UC_STATUS_LBN) >=
                    PCS_UC_STATUS_FW_SAVE)
                        break;
                if (time_after(jiffies, timeout))
                        return -ETIMEDOUT;
                msleep(QT2025C_FWSTART_WAIT);
        }

        return 0;
}

static void qt2025c_restart_firmware(struct efx_nic *efx)
{
        /* Restart microcontroller execution of firmware from RAM */
        efx_mdio_write(efx, 3, 0xe854, 0x00c0);
        efx_mdio_write(efx, 3, 0xe854, 0x0040);
        msleep(50);
}

static int qt2025c_wait_reset(struct efx_nic *efx)
{
        int rc;

        rc = qt2025c_wait_heartbeat(efx);
        if (rc != 0)
                return rc;

        rc = qt2025c_wait_fw_status_good(efx);
        if (rc == -ETIMEDOUT) {
                /* Bug 17689: occasionally heartbeat starts but firmware status
                 * code never progresses beyond 0x00.  Try again, once, after
                 * restarting execution of the firmware image. */
                netif_dbg(efx, hw, efx->net_dev,
                          "bashing QT2025C microcontroller\n");
                qt2025c_restart_firmware(efx);
                rc = qt2025c_wait_heartbeat(efx);
                if (rc != 0)
                        return rc;
                rc = qt2025c_wait_fw_status_good(efx);
        }

        return rc;
}

static void qt2025c_firmware_id(struct efx_nic *efx)
{
        struct qt202x_phy_data *phy_data = efx->phy_data;
        u8 firmware_id[9];
        size_t i;

        for (i = 0; i < sizeof(firmware_id); i++)
                firmware_id[i] = efx_mdio_read(efx, MDIO_MMD_PCS,
                                               PCS_FW_PRODUCT_CODE_1 + i);
        netif_info(efx, probe, efx->net_dev,
                   "QT2025C firmware %xr%d v%d.%d.%d.%d [20%02d-%02d-%02d]\n",
                   (firmware_id[0] << 8) | firmware_id[1], firmware_id[2],
                   firmware_id[3] >> 4, firmware_id[3] & 0xf,
                   firmware_id[4], firmware_id[5],
                   firmware_id[6], firmware_id[7], firmware_id[8]);
        phy_data->firmware_ver = ((firmware_id[3] & 0xf0) << 20) |
                                 ((firmware_id[3] & 0x0f) << 16) |
                                 (firmware_id[4] << 8) | firmware_id[5];
}

static void qt2025c_bug17190_workaround(struct efx_nic *efx)
{
        struct qt202x_phy_data *phy_data = efx->phy_data;

        /* The PHY can get stuck in a state where it reports PHY_XS and PMA/PMD
         * layers up, but PCS down (no block_lock).  If we notice this state
         * persisting for a couple of seconds, we switch PMA/PMD loopback
         * briefly on and then off again, which is normally sufficient to
         * recover it.
         */
        if (efx->link_state.up ||
            !efx_mdio_links_ok(efx, MDIO_DEVS_PMAPMD | MDIO_DEVS_PHYXS)) {
                phy_data->bug17190_in_bad_state = false;
                return;
        }

        if (!phy_data->bug17190_in_bad_state) {
                phy_data->bug17190_in_bad_state = true;
                phy_data->bug17190_timer = jiffies + BUG17190_INTERVAL;
                return;
        }

        if (time_after_eq(jiffies, phy_data->bug17190_timer)) {
                netif_dbg(efx, hw, efx->net_dev, "bashing QT2025C PMA/PMD\n");
                efx_mdio_set_flag(efx, MDIO_MMD_PMAPMD, MDIO_CTRL1,
                                  MDIO_PMA_CTRL1_LOOPBACK, true);
                msleep(100);
                efx_mdio_set_flag(efx, MDIO_MMD_PMAPMD, MDIO_CTRL1,
                                  MDIO_PMA_CTRL1_LOOPBACK, false);
                phy_data->bug17190_timer = jiffies + BUG17190_INTERVAL;
        }
}

static int qt2025c_select_phy_mode(struct efx_nic *efx)
{
        struct qt202x_phy_data *phy_data = efx->phy_data;
        struct falcon_board *board = falcon_board(efx);
        int reg, rc, i;
        uint16_t phy_op_mode;

        /* Only 2.0.1.0+ PHY firmware supports the more optimal SFP+
         * Self-Configure mode.  Don't attempt any switching if we encounter
         * older firmware. */
        if (phy_data->firmware_ver < 0x02000100)
                return 0;

        /* In general we will get optimal behaviour in "SFP+ Self-Configure"
         * mode; however, that powers down most of the PHY when no module is
         * present, so we must use a different mode (any fixed mode will do)
         * to be sure that loopbacks will work. */
        phy_op_mode = (efx->loopback_mode == LOOPBACK_NONE) ? 0x0038 : 0x0020;

        /* Only change mode if really necessary */
        reg = efx_mdio_read(efx, 1, 0xc319);
        if ((reg & 0x0038) == phy_op_mode)
                return 0;
        netif_dbg(efx, hw, efx->net_dev, "Switching PHY to mode 0x%04x\n",
                  phy_op_mode);

        /* This sequence replicates the register writes configured in the boot
         * EEPROM (including the differences between board revisions), except
         * that the operating mode is changed, and the PHY is prevented from
         * unnecessarily reloading the main firmware image again. */
        efx_mdio_write(efx, 1, 0xc300, 0x0000);
        /* (Note: this portion of the boot EEPROM sequence, which bit-bashes 9
         * STOPs onto the firmware/module I2C bus to reset it, varies across
         * board revisions, as the bus is connected to different GPIO/LED
         * outputs on the PHY.) */
        if (board->major == 0 && board->minor < 2) {
                efx_mdio_write(efx, 1, 0xc303, 0x4498);
                for (i = 0; i < 9; i++) {
                        efx_mdio_write(efx, 1, 0xc303, 0x4488);
                        efx_mdio_write(efx, 1, 0xc303, 0x4480);
                        efx_mdio_write(efx, 1, 0xc303, 0x4490);
                        efx_mdio_write(efx, 1, 0xc303, 0x4498);
                }
        } else {
                efx_mdio_write(efx, 1, 0xc303, 0x0920);
                efx_mdio_write(efx, 1, 0xd008, 0x0004);
                for (i = 0; i < 9; i++) {
                        efx_mdio_write(efx, 1, 0xc303, 0x0900);
                        efx_mdio_write(efx, 1, 0xd008, 0x0005);
                        efx_mdio_write(efx, 1, 0xc303, 0x0920);
                        efx_mdio_write(efx, 1, 0xd008, 0x0004);
                }
                efx_mdio_write(efx, 1, 0xc303, 0x4900);
        }
        efx_mdio_write(efx, 1, 0xc303, 0x4900);
        efx_mdio_write(efx, 1, 0xc302, 0x0004);
        efx_mdio_write(efx, 1, 0xc316, 0x0013);
        efx_mdio_write(efx, 1, 0xc318, 0x0054);
        efx_mdio_write(efx, 1, 0xc319, phy_op_mode);
        efx_mdio_write(efx, 1, 0xc31a, 0x0098);
        efx_mdio_write(efx, 3, 0x0026, 0x0e00);
        efx_mdio_write(efx, 3, 0x0027, 0x0013);
        efx_mdio_write(efx, 3, 0x0028, 0xa528);
        efx_mdio_write(efx, 1, 0xd006, 0x000a);
        efx_mdio_write(efx, 1, 0xd007, 0x0009);
        efx_mdio_write(efx, 1, 0xd008, 0x0004);
        /* This additional write is not present in the boot EEPROM.  It
         * prevents the PHY's internal boot ROM doing another pointless (and
         * slow) reload of the firmware image (the microcontroller's code
         * memory is not affected by the microcontroller reset). */
        efx_mdio_write(efx, 1, 0xc317, 0x00ff);
        /* PMA/PMD loopback sets RXIN to inverse polarity and the firmware
         * restart doesn't reset it. We need to do that ourselves. */
        efx_mdio_set_flag(efx, 1, PMA_PMD_MODE_REG,
                          1 << PMA_PMD_RXIN_SEL_LBN, false);
        efx_mdio_write(efx, 1, 0xc300, 0x0002);
        msleep(20);

        /* Restart microcontroller execution of firmware from RAM */
        qt2025c_restart_firmware(efx);

        /* Wait for the microcontroller to be ready again */
        rc = qt2025c_wait_reset(efx);
        if (rc < 0) {
                netif_err(efx, hw, efx->net_dev,
                          "PHY microcontroller reset during mode switch "
                          "timed out\n");
                return rc;
        }

        return 0;
}

static int qt202x_reset_phy(struct efx_nic *efx)
{
        int rc;

        if (efx->phy_type == PHY_TYPE_QT2025C) {
                /* Wait for the reset triggered by falcon_reset_hw()
                 * to complete */
                rc = qt2025c_wait_reset(efx);
                if (rc < 0)
                        goto fail;
        } else {
                /* Reset the PHYXS MMD. This is documented as doing
                 * a complete soft reset. */
                rc = efx_mdio_reset_mmd(efx, MDIO_MMD_PHYXS,
                                        QT2022C2_MAX_RESET_TIME /
                                        QT2022C2_RESET_WAIT,
                                        QT2022C2_RESET_WAIT);
                if (rc < 0)
                        goto fail;
        }

        /* Wait 250ms for the PHY to complete bootup */
        msleep(250);

        falcon_board(efx)->type->init_phy(efx);

        return 0;

 fail:
        netif_err(efx, hw, efx->net_dev, "PHY reset timed out\n");
        return rc;
}

static int qt202x_phy_probe(struct efx_nic *efx)
{
        struct qt202x_phy_data *phy_data;

        phy_data = kzalloc(sizeof(struct qt202x_phy_data), GFP_KERNEL);
        if (!phy_data)
                return -ENOMEM;
        efx->phy_data = phy_data;
        phy_data->phy_mode = efx->phy_mode;
        phy_data->bug17190_in_bad_state = false;
        phy_data->bug17190_timer = 0;

        efx->mdio.mmds = QT202X_REQUIRED_DEVS;
        efx->mdio.mode_support = MDIO_SUPPORTS_C45 | MDIO_EMULATE_C22;
        efx->loopback_modes = QT202X_LOOPBACKS | FALCON_XMAC_LOOPBACKS;
        return 0;
}

static int qt202x_phy_init(struct efx_nic *efx)
{
        u32 devid;
        int rc;

        rc = qt202x_reset_phy(efx);
        if (rc) {
                netif_err(efx, probe, efx->net_dev, "PHY init failed\n");
                return rc;
        }

        devid = efx_mdio_read_id(efx, MDIO_MMD_PHYXS);
        netif_info(efx, probe, efx->net_dev,
                   "PHY ID reg %x (OUI %06x model %02x revision %x)\n",
                   devid, efx_mdio_id_oui(devid), efx_mdio_id_model(devid),
                   efx_mdio_id_rev(devid));

        if (efx->phy_type == PHY_TYPE_QT2025C)
                qt2025c_firmware_id(efx);

        return 0;
}

static int qt202x_link_ok(struct efx_nic *efx)
{
        return efx_mdio_links_ok(efx, QT202X_REQUIRED_DEVS);
}

static bool qt202x_phy_poll(struct efx_nic *efx)
{
        bool was_up = efx->link_state.up;

        efx->link_state.up = qt202x_link_ok(efx);
        efx->link_state.speed = 10000;
        efx->link_state.fd = true;
        efx->link_state.fc = efx->wanted_fc;

        if (efx->phy_type == PHY_TYPE_QT2025C)
                qt2025c_bug17190_workaround(efx);

        return efx->link_state.up != was_up;
}

static int qt202x_phy_reconfigure(struct efx_nic *efx)
{
        struct qt202x_phy_data *phy_data = efx->phy_data;

        if (efx->phy_type == PHY_TYPE_QT2025C) {
                int rc = qt2025c_select_phy_mode(efx);
                if (rc)
                        return rc;

                /* There are several different register bits which can
                 * disable TX (and save power) on direct-attach cables
                 * or optical transceivers, varying somewhat between
                 * firmware versions.  Only 'static mode' appears to
                 * cover everything. */
                mdio_set_flag(
                        &efx->mdio, efx->mdio.prtad, MDIO_MMD_PMAPMD,
                        PMA_PMD_FTX_CTRL2_REG, 1 << PMA_PMD_FTX_STATIC_LBN,
                        efx->phy_mode & PHY_MODE_TX_DISABLED ||
                        efx->phy_mode & PHY_MODE_LOW_POWER ||
                        efx->loopback_mode == LOOPBACK_PCS ||
                        efx->loopback_mode == LOOPBACK_PMAPMD);
        } else {
                /* Reset the PHY when moving from tx off to tx on */
                if (!(efx->phy_mode & PHY_MODE_TX_DISABLED) &&
                    (phy_data->phy_mode & PHY_MODE_TX_DISABLED))
                        qt202x_reset_phy(efx);

                efx_mdio_transmit_disable(efx);
        }

        efx_mdio_phy_reconfigure(efx);

        phy_data->phy_mode = efx->phy_mode;

        return 0;
}

static void qt202x_phy_get_settings(struct efx_nic *efx, struct ethtool_cmd *ecmd)
{
        mdio45_ethtool_gset(&efx->mdio, ecmd);
}

static void qt202x_phy_remove(struct efx_nic *efx)
{
        /* Free the context block */
        kfree(efx->phy_data);
        efx->phy_data = NULL;
}

static int qt202x_phy_get_module_info(struct efx_nic *efx,
                                      struct ethtool_modinfo *modinfo)
{
        modinfo->type = ETH_MODULE_SFF_8079;
        modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
        return 0;
}

static int qt202x_phy_get_module_eeprom(struct efx_nic *efx,
                                        struct ethtool_eeprom *ee, u8 *data)
{
        int mmd, reg_base, rc, i;               

        if (efx->phy_type == PHY_TYPE_QT2025C) {
                mmd = MDIO_MMD_PCS;
                reg_base = 0xd000;
        } else {
                mmd = MDIO_MMD_PMAPMD;
                reg_base = 0x8007;
        }

        for (i = 0; i < ee->len; i++) {
                rc = efx_mdio_read(efx, mmd, reg_base + ee->offset + i);
                if (rc < 0)
                        return rc;
                data[i] = rc;
        }

        return 0;
}

const struct efx_phy_operations falcon_qt202x_phy_ops = {
        .probe           = qt202x_phy_probe,
        .init            = qt202x_phy_init,
        .reconfigure     = qt202x_phy_reconfigure,
        .poll            = qt202x_phy_poll,
        .fini            = efx_port_dummy_op_void,
        .remove          = qt202x_phy_remove,
        .get_settings    = qt202x_phy_get_settings,
        .set_settings    = efx_mdio_set_settings,
        .test_alive      = efx_mdio_test_alive,
        .get_module_eeprom = qt202x_phy_get_module_eeprom,
        .get_module_info = qt202x_phy_get_module_info,
};