/*
 * Copyright (c) 2004-2008 Reyk Floeter <reyk@openbsd.org>
 * Copyright (c) 2006-2008 Nick Kossifidis <mickflemm@gmail.com>
 * Copyright (c) 2007-2008 Luis Rodriguez <mcgrof@winlab.rutgers.edu>
 * Copyright (c) 2007-2008 Pavel Roskin <proski@gnu.org>
 * Copyright (c) 2007-2008 Jiri Slaby <jirislaby@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

/****************************\
  Reset function and helpers
\****************************/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <asm/unaligned.h>

#include <linux/pci.h>          /* To determine if a card is pci-e */
#include <linux/log2.h>
#include <linux/platform_device.h>
#include "ath5k.h"
#include "reg.h"
#include "debug.h"


/**
 * DOC: Reset function and helpers
 *
 * Here we implement the main reset routine, used to bring the card
 * to a working state and ready to receive. We also handle routines
 * that don't fit on other places such as clock, sleep and power control
 */


/******************\
* Helper functions *
\******************/

/**
 * ath5k_hw_register_timeout() - Poll a register for a flag/field change
 * @ah: The &struct ath5k_hw
 * @reg: The register to read
 * @flag: The flag/field to check on the register
 * @val: The field value we expect (if we check a field)
 * @is_set: Instead of checking if the flag got cleared, check if it got set
 *
 * Some registers contain flags that indicate that an operation is
 * running. We use this function to poll these registers and check
 * if these flags get cleared. We also use it to poll a register
 * field (containing multiple flags) until it gets a specific value.
 *
 * Returns -EAGAIN if we exceeded AR5K_TUNE_REGISTER_TIMEOUT * 15us or 0
 */
int
ath5k_hw_register_timeout(struct ath5k_hw *ah, u32 reg, u32 flag, u32 val,
                              bool is_set)
{
        int i;
        u32 data;

        for (i = AR5K_TUNE_REGISTER_TIMEOUT; i > 0; i--) {
                data = ath5k_hw_reg_read(ah, reg);
                if (is_set && (data & flag))
                        break;
                else if ((data & flag) == val)
                        break;
                udelay(15);
        }

        return (i <= 0) ? -EAGAIN : 0;
}


/*************************\
* Clock related functions *
\*************************/

/**
 * ath5k_hw_htoclock() - Translate usec to hw clock units
 * @ah: The &struct ath5k_hw
 * @usec: value in microseconds
 *
 * Translate usecs to hw clock units based on the current
 * hw clock rate.
 *
 * Returns number of clock units
 */
unsigned int
ath5k_hw_htoclock(struct ath5k_hw *ah, unsigned int usec)
{
        struct ath_common *common = ath5k_hw_common(ah);
        return usec * common->clockrate;
}

/**
 * ath5k_hw_clocktoh() - Translate hw clock units to usec
 * @ah: The &struct ath5k_hw
 * @clock: value in hw clock units
 *
 * Translate hw clock units to usecs based on the current
 * hw clock rate.
 *
 * Returns number of usecs
 */
unsigned int
ath5k_hw_clocktoh(struct ath5k_hw *ah, unsigned int clock)
{
        struct ath_common *common = ath5k_hw_common(ah);
        return clock / common->clockrate;
}

/**
 * ath5k_hw_init_core_clock() - Initialize core clock
 * @ah: The &struct ath5k_hw
 *
 * Initialize core clock parameters (usec, usec32, latencies etc),
 * based on current bwmode and chipset properties.
 */
static void
ath5k_hw_init_core_clock(struct ath5k_hw *ah)
{
        struct ieee80211_channel *channel = ah->ah_current_channel;
        struct ath_common *common = ath5k_hw_common(ah);
        u32 usec_reg, txlat, rxlat, usec, clock, sclock, txf2txs;

        /*
         * Set core clock frequency
         */
        switch (channel->hw_value) {
        case AR5K_MODE_11A:
                clock = 40;
                break;
        case AR5K_MODE_11B:
                clock = 22;
                break;
        case AR5K_MODE_11G:
        default:
                clock = 44;
                break;
        }

        /* Use clock multiplier for non-default
         * bwmode */
        switch (ah->ah_bwmode) {
        case AR5K_BWMODE_40MHZ:
                clock *= 2;
                break;
        case AR5K_BWMODE_10MHZ:
                clock /= 2;
                break;
        case AR5K_BWMODE_5MHZ:
                clock /= 4;
                break;
        default:
                break;
        }

        common->clockrate = clock;

        /*
         * Set USEC parameters
         */
        /* Set USEC counter on PCU*/
        usec = clock - 1;
        usec = AR5K_REG_SM(usec, AR5K_USEC_1);

        /* Set usec duration on DCU */
        if (ah->ah_version != AR5K_AR5210)
                AR5K_REG_WRITE_BITS(ah, AR5K_DCU_GBL_IFS_MISC,
                                        AR5K_DCU_GBL_IFS_MISC_USEC_DUR,
                                        clock);

        /* Set 32MHz USEC counter */
        if ((ah->ah_radio == AR5K_RF5112) ||
            (ah->ah_radio == AR5K_RF2413) ||
            (ah->ah_radio == AR5K_RF5413) ||
            (ah->ah_radio == AR5K_RF2316) ||
            (ah->ah_radio == AR5K_RF2317))
                /* Remain on 40MHz clock ? */
                sclock = 40 - 1;
        else
                sclock = 32 - 1;
        sclock = AR5K_REG_SM(sclock, AR5K_USEC_32);

        /*
         * Set tx/rx latencies
         */
        usec_reg = ath5k_hw_reg_read(ah, AR5K_USEC_5211);
        txlat = AR5K_REG_MS(usec_reg, AR5K_USEC_TX_LATENCY_5211);
        rxlat = AR5K_REG_MS(usec_reg, AR5K_USEC_RX_LATENCY_5211);

        /*
         * Set default Tx frame to Tx data start delay
         */
        txf2txs = AR5K_INIT_TXF2TXD_START_DEFAULT;

        /*
         * 5210 initvals don't include usec settings
         * so we need to use magic values here for
         * tx/rx latencies
         */
        if (ah->ah_version == AR5K_AR5210) {
                /* same for turbo */
                txlat = AR5K_INIT_TX_LATENCY_5210;
                rxlat = AR5K_INIT_RX_LATENCY_5210;
        }

        if (ah->ah_mac_srev < AR5K_SREV_AR5211) {
                /* 5311 has different tx/rx latency masks
                 * from 5211, since we deal 5311 the same
                 * as 5211 when setting initvals, shift
                 * values here to their proper locations
                 *
                 * Note: Initvals indicate tx/rx/ latencies
                 * are the same for turbo mode */
                txlat = AR5K_REG_SM(txlat, AR5K_USEC_TX_LATENCY_5210);
                rxlat = AR5K_REG_SM(rxlat, AR5K_USEC_RX_LATENCY_5210);
        } else
        switch (ah->ah_bwmode) {
        case AR5K_BWMODE_10MHZ:
                txlat = AR5K_REG_SM(txlat * 2,
                                AR5K_USEC_TX_LATENCY_5211);
                rxlat = AR5K_REG_SM(AR5K_INIT_RX_LAT_MAX,
                                AR5K_USEC_RX_LATENCY_5211);
                txf2txs = AR5K_INIT_TXF2TXD_START_DELAY_10MHZ;
                break;
        case AR5K_BWMODE_5MHZ:
                txlat = AR5K_REG_SM(txlat * 4,
                                AR5K_USEC_TX_LATENCY_5211);
                rxlat = AR5K_REG_SM(AR5K_INIT_RX_LAT_MAX,
                                AR5K_USEC_RX_LATENCY_5211);
                txf2txs = AR5K_INIT_TXF2TXD_START_DELAY_5MHZ;
                break;
        case AR5K_BWMODE_40MHZ:
                txlat = AR5K_INIT_TX_LAT_MIN;
                rxlat = AR5K_REG_SM(rxlat / 2,
                                AR5K_USEC_RX_LATENCY_5211);
                txf2txs = AR5K_INIT_TXF2TXD_START_DEFAULT;
                break;
        default:
                break;
        }

        usec_reg = (usec | sclock | txlat | rxlat);
        ath5k_hw_reg_write(ah, usec_reg, AR5K_USEC);

        /* On 5112 set tx frame to tx data start delay */
        if (ah->ah_radio == AR5K_RF5112) {
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_RF_CTL2,
                                        AR5K_PHY_RF_CTL2_TXF2TXD_START,
                                        txf2txs);
        }
}

/**
 * ath5k_hw_set_sleep_clock() - Setup sleep clock operation
 * @ah: The &struct ath5k_hw
 * @enable: Enable sleep clock operation (false to disable)
 *
 * If there is an external 32KHz crystal available, use it
 * as ref. clock instead of 32/40MHz clock and baseband clocks
 * to save power during sleep or restore normal 32/40MHz
 * operation.
 *
 * NOTE: When operating on 32KHz certain PHY registers (27 - 31,
 * 123 - 127) require delay on access.
 */
static void
ath5k_hw_set_sleep_clock(struct ath5k_hw *ah, bool enable)
{
        struct ath5k_eeprom_info *ee = &ah->ah_capabilities.cap_eeprom;
        u32 scal, spending, sclock;

        /* Only set 32KHz settings if we have an external
         * 32KHz crystal present */
        if ((AR5K_EEPROM_HAS32KHZCRYSTAL(ee->ee_misc1) ||
        AR5K_EEPROM_HAS32KHZCRYSTAL_OLD(ee->ee_misc1)) &&
        enable) {

                /* 1 usec/cycle */
                AR5K_REG_WRITE_BITS(ah, AR5K_USEC_5211, AR5K_USEC_32, 1);
                /* Set up tsf increment on each cycle */
                AR5K_REG_WRITE_BITS(ah, AR5K_TSF_PARM, AR5K_TSF_PARM_INC, 61);

                /* Set baseband sleep control registers
                 * and sleep control rate */
                ath5k_hw_reg_write(ah, 0x1f, AR5K_PHY_SCR);

                if ((ah->ah_radio == AR5K_RF5112) ||
                (ah->ah_radio == AR5K_RF5413) ||
                (ah->ah_radio == AR5K_RF2316) ||
                (ah->ah_mac_version == (AR5K_SREV_AR2417 >> 4)))
                        spending = 0x14;
                else
                        spending = 0x18;
                ath5k_hw_reg_write(ah, spending, AR5K_PHY_SPENDING);

                if ((ah->ah_radio == AR5K_RF5112) ||
                (ah->ah_radio == AR5K_RF5413) ||
                (ah->ah_mac_version == (AR5K_SREV_AR2417 >> 4))) {
                        ath5k_hw_reg_write(ah, 0x26, AR5K_PHY_SLMT);
                        ath5k_hw_reg_write(ah, 0x0d, AR5K_PHY_SCAL);
                        ath5k_hw_reg_write(ah, 0x07, AR5K_PHY_SCLOCK);
                        ath5k_hw_reg_write(ah, 0x3f, AR5K_PHY_SDELAY);
                        AR5K_REG_WRITE_BITS(ah, AR5K_PCICFG,
                                AR5K_PCICFG_SLEEP_CLOCK_RATE, 0x02);
                } else {
                        ath5k_hw_reg_write(ah, 0x0a, AR5K_PHY_SLMT);
                        ath5k_hw_reg_write(ah, 0x0c, AR5K_PHY_SCAL);
                        ath5k_hw_reg_write(ah, 0x03, AR5K_PHY_SCLOCK);
                        ath5k_hw_reg_write(ah, 0x20, AR5K_PHY_SDELAY);
                        AR5K_REG_WRITE_BITS(ah, AR5K_PCICFG,
                                AR5K_PCICFG_SLEEP_CLOCK_RATE, 0x03);
                }

                /* Enable sleep clock operation */
                AR5K_REG_ENABLE_BITS(ah, AR5K_PCICFG,
                                AR5K_PCICFG_SLEEP_CLOCK_EN);

        } else {

                /* Disable sleep clock operation and
                 * restore default parameters */
                AR5K_REG_DISABLE_BITS(ah, AR5K_PCICFG,
                                AR5K_PCICFG_SLEEP_CLOCK_EN);

                AR5K_REG_WRITE_BITS(ah, AR5K_PCICFG,
                                AR5K_PCICFG_SLEEP_CLOCK_RATE, 0);

                /* Set DAC/ADC delays */
                ath5k_hw_reg_write(ah, 0x1f, AR5K_PHY_SCR);
                ath5k_hw_reg_write(ah, AR5K_PHY_SLMT_32MHZ, AR5K_PHY_SLMT);

                if (ah->ah_mac_version == (AR5K_SREV_AR2417 >> 4))
                        scal = AR5K_PHY_SCAL_32MHZ_2417;
                else if (ee->ee_is_hb63)
                        scal = AR5K_PHY_SCAL_32MHZ_HB63;
                else
                        scal = AR5K_PHY_SCAL_32MHZ;
                ath5k_hw_reg_write(ah, scal, AR5K_PHY_SCAL);

                ath5k_hw_reg_write(ah, AR5K_PHY_SCLOCK_32MHZ, AR5K_PHY_SCLOCK);
                ath5k_hw_reg_write(ah, AR5K_PHY_SDELAY_32MHZ, AR5K_PHY_SDELAY);

                if ((ah->ah_radio == AR5K_RF5112) ||
                (ah->ah_radio == AR5K_RF5413) ||
                (ah->ah_radio == AR5K_RF2316) ||
                (ah->ah_mac_version == (AR5K_SREV_AR2417 >> 4)))
                        spending = 0x14;
                else
                        spending = 0x18;
                ath5k_hw_reg_write(ah, spending, AR5K_PHY_SPENDING);

                /* Set up tsf increment on each cycle */
                AR5K_REG_WRITE_BITS(ah, AR5K_TSF_PARM, AR5K_TSF_PARM_INC, 1);

                if ((ah->ah_radio == AR5K_RF5112) ||
                        (ah->ah_radio == AR5K_RF5413) ||
                        (ah->ah_radio == AR5K_RF2316) ||
                        (ah->ah_radio == AR5K_RF2317))
                        sclock = 40 - 1;
                else
                        sclock = 32 - 1;
                AR5K_REG_WRITE_BITS(ah, AR5K_USEC_5211, AR5K_USEC_32, sclock);
        }
}


/*********************\
* Reset/Sleep control *
\*********************/

/**
 * ath5k_hw_nic_reset() - Reset the various chipset units
 * @ah: The &struct ath5k_hw
 * @val: Mask to indicate what units to reset
 *
 * To reset the various chipset units we need to write
 * the mask to AR5K_RESET_CTL and poll the register until
 * all flags are cleared.
 *
 * Returns 0 if we are O.K. or -EAGAIN (from athk5_hw_register_timeout)
 */
static int
ath5k_hw_nic_reset(struct ath5k_hw *ah, u32 val)
{
        int ret;
        u32 mask = val ? val : ~0U;

        /* Read-and-clear RX Descriptor Pointer*/
        ath5k_hw_reg_read(ah, AR5K_RXDP);

        /*
         * Reset the device and wait until success
         */
        ath5k_hw_reg_write(ah, val, AR5K_RESET_CTL);

        /* Wait at least 128 PCI clocks */
        usleep_range(15, 20);

        if (ah->ah_version == AR5K_AR5210) {
                val &= AR5K_RESET_CTL_PCU | AR5K_RESET_CTL_DMA
                        | AR5K_RESET_CTL_MAC | AR5K_RESET_CTL_PHY;
                mask &= AR5K_RESET_CTL_PCU | AR5K_RESET_CTL_DMA
                        | AR5K_RESET_CTL_MAC | AR5K_RESET_CTL_PHY;
        } else {
                val &= AR5K_RESET_CTL_PCU | AR5K_RESET_CTL_BASEBAND;
                mask &= AR5K_RESET_CTL_PCU | AR5K_RESET_CTL_BASEBAND;
        }

        ret = ath5k_hw_register_timeout(ah, AR5K_RESET_CTL, mask, val, false);

        /*
         * Reset configuration register (for hw byte-swap). Note that this
         * is only set for big endian. We do the necessary magic in
         * AR5K_INIT_CFG.
         */
        if ((val & AR5K_RESET_CTL_PCU) == 0)
                ath5k_hw_reg_write(ah, AR5K_INIT_CFG, AR5K_CFG);

        return ret;
}

/**
 * ath5k_hw_wisoc_reset() -  Reset AHB chipset
 * @ah: The &struct ath5k_hw
 * @flags: Mask to indicate what units to reset
 *
 * Same as ath5k_hw_nic_reset but for AHB based devices
 *
 * Returns 0 if we are O.K. or -EAGAIN (from athk5_hw_register_timeout)
 */
static int
ath5k_hw_wisoc_reset(struct ath5k_hw *ah, u32 flags)
{
        u32 mask = flags ? flags : ~0U;
        u32 __iomem *reg;
        u32 regval;
        u32 val = 0;

        /* ah->ah_mac_srev is not available at this point yet */
        if (ah->devid >= AR5K_SREV_AR2315_R6) {
                reg = (u32 __iomem *) AR5K_AR2315_RESET;
                if (mask & AR5K_RESET_CTL_PCU)
                        val |= AR5K_AR2315_RESET_WMAC;
                if (mask & AR5K_RESET_CTL_BASEBAND)
                        val |= AR5K_AR2315_RESET_BB_WARM;
        } else {
                reg = (u32 __iomem *) AR5K_AR5312_RESET;
                if (to_platform_device(ah->dev)->id == 0) {
                        if (mask & AR5K_RESET_CTL_PCU)
                                val |= AR5K_AR5312_RESET_WMAC0;
                        if (mask & AR5K_RESET_CTL_BASEBAND)
                                val |= AR5K_AR5312_RESET_BB0_COLD |
                                       AR5K_AR5312_RESET_BB0_WARM;
                } else {
                        if (mask & AR5K_RESET_CTL_PCU)
                                val |= AR5K_AR5312_RESET_WMAC1;
                        if (mask & AR5K_RESET_CTL_BASEBAND)
                                val |= AR5K_AR5312_RESET_BB1_COLD |
                                       AR5K_AR5312_RESET_BB1_WARM;
                }
        }

        /* Put BB/MAC into reset */
        regval = ioread32(reg);
        iowrite32(regval | val, reg);
        regval = ioread32(reg);
        usleep_range(100, 150);

        /* Bring BB/MAC out of reset */
        iowrite32(regval & ~val, reg);
        regval = ioread32(reg);

        /*
         * Reset configuration register (for hw byte-swap). Note that this
         * is only set for big endian. We do the necessary magic in
         * AR5K_INIT_CFG.
         */
        if ((flags & AR5K_RESET_CTL_PCU) == 0)
                ath5k_hw_reg_write(ah, AR5K_INIT_CFG, AR5K_CFG);

        return 0;
}

/**
 * ath5k_hw_set_power_mode() - Set power mode
 * @ah: The &struct ath5k_hw
 * @mode: One of enum ath5k_power_mode
 * @set_chip: Set to true to write sleep control register
 * @sleep_duration: How much time the device is allowed to sleep
 * when sleep logic is enabled (in 128 microsecond increments).
 *
 * This function is used to configure sleep policy and allowed
 * sleep modes. For more information check out the sleep control
 * register on reg.h and STA_ID1.
 *
 * Returns 0 on success, -EIO if chip didn't wake up or -EINVAL if an invalid
 * mode is requested.
 */
static int
ath5k_hw_set_power_mode(struct ath5k_hw *ah, enum ath5k_power_mode mode,
                              bool set_chip, u16 sleep_duration)
{
        unsigned int i;
        u32 staid, data;

        staid = ath5k_hw_reg_read(ah, AR5K_STA_ID1);

        switch (mode) {
        case AR5K_PM_AUTO:
                staid &= ~AR5K_STA_ID1_DEFAULT_ANTENNA;
                /* fallthrough */
        case AR5K_PM_NETWORK_SLEEP:
                if (set_chip)
                        ath5k_hw_reg_write(ah,
                                AR5K_SLEEP_CTL_SLE_ALLOW |
                                sleep_duration,
                                AR5K_SLEEP_CTL);

                staid |= AR5K_STA_ID1_PWR_SV;
                break;

        case AR5K_PM_FULL_SLEEP:
                if (set_chip)
                        ath5k_hw_reg_write(ah, AR5K_SLEEP_CTL_SLE_SLP,
                                AR5K_SLEEP_CTL);

                staid |= AR5K_STA_ID1_PWR_SV;
                break;

        case AR5K_PM_AWAKE:

                staid &= ~AR5K_STA_ID1_PWR_SV;

                if (!set_chip)
                        goto commit;

                data = ath5k_hw_reg_read(ah, AR5K_SLEEP_CTL);

                /* If card is down we 'll get 0xffff... so we
                 * need to clean this up before we write the register
                 */
                if (data & 0xffc00000)
                        data = 0;
                else
                        /* Preserve sleep duration etc */
                        data = data & ~AR5K_SLEEP_CTL_SLE;

                ath5k_hw_reg_write(ah, data | AR5K_SLEEP_CTL_SLE_WAKE,
                                                        AR5K_SLEEP_CTL);
                usleep_range(15, 20);

                for (i = 200; i > 0; i--) {
                        /* Check if the chip did wake up */
                        if ((ath5k_hw_reg_read(ah, AR5K_PCICFG) &
                                        AR5K_PCICFG_SPWR_DN) == 0)
                                break;

                        /* Wait a bit and retry */
                        usleep_range(50, 75);
                        ath5k_hw_reg_write(ah, data | AR5K_SLEEP_CTL_SLE_WAKE,
                                                        AR5K_SLEEP_CTL);
                }

                /* Fail if the chip didn't wake up */
                if (i == 0)
                        return -EIO;

                break;

        default:
                return -EINVAL;
        }

commit:
        ath5k_hw_reg_write(ah, staid, AR5K_STA_ID1);

        return 0;
}

/**
 * ath5k_hw_on_hold() - Put device on hold
 * @ah: The &struct ath5k_hw
 *
 * Put MAC and Baseband on warm reset and keep that state
 * (don't clean sleep control register). After this MAC
 * and Baseband are disabled and a full reset is needed
 * to come back. This way we save as much power as possible
 * without putting the card on full sleep.
 *
 * Returns 0 on success or -EIO on error
 */
int
ath5k_hw_on_hold(struct ath5k_hw *ah)
{
        struct pci_dev *pdev = ah->pdev;
        u32 bus_flags;
        int ret;

        if (ath5k_get_bus_type(ah) == ATH_AHB)
                return 0;

        /* Make sure device is awake */
        ret = ath5k_hw_set_power_mode(ah, AR5K_PM_AWAKE, true, 0);
        if (ret) {
                ATH5K_ERR(ah, "failed to wakeup the MAC Chip\n");
                return ret;
        }

        /*
         * Put chipset on warm reset...
         *
         * Note: putting PCI core on warm reset on PCI-E cards
         * results card to hang and always return 0xffff... so
         * we ignore that flag for PCI-E cards. On PCI cards
         * this flag gets cleared after 64 PCI clocks.
         */
        bus_flags = (pdev && pci_is_pcie(pdev)) ? 0 : AR5K_RESET_CTL_PCI;

        if (ah->ah_version == AR5K_AR5210) {
                ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
                        AR5K_RESET_CTL_MAC | AR5K_RESET_CTL_DMA |
                        AR5K_RESET_CTL_PHY | AR5K_RESET_CTL_PCI);
                        usleep_range(2000, 2500);
        } else {
                ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
                        AR5K_RESET_CTL_BASEBAND | bus_flags);
        }

        if (ret) {
                ATH5K_ERR(ah, "failed to put device on warm reset\n");
                return -EIO;
        }

        /* ...wakeup again!*/
        ret = ath5k_hw_set_power_mode(ah, AR5K_PM_AWAKE, true, 0);
        if (ret) {
                ATH5K_ERR(ah, "failed to put device on hold\n");
                return ret;
        }

        return ret;
}

/**
 * ath5k_hw_nic_wakeup() - Force card out of sleep
 * @ah: The &struct ath5k_hw
 * @channel: The &struct ieee80211_channel
 *
 * Bring up MAC + PHY Chips and program PLL
 * NOTE: Channel is NULL for the initial wakeup.
 *
 * Returns 0 on success, -EIO on hw failure or -EINVAL for false channel infos
 */
int
ath5k_hw_nic_wakeup(struct ath5k_hw *ah, struct ieee80211_channel *channel)
{
        struct pci_dev *pdev = ah->pdev;
        u32 turbo, mode, clock, bus_flags;
        int ret;

        turbo = 0;
        mode = 0;
        clock = 0;

        if ((ath5k_get_bus_type(ah) != ATH_AHB) || channel) {
                /* Wakeup the device */
                ret = ath5k_hw_set_power_mode(ah, AR5K_PM_AWAKE, true, 0);
                if (ret) {
                        ATH5K_ERR(ah, "failed to wakeup the MAC Chip\n");
                        return ret;
                }
        }

        /*
         * Put chipset on warm reset...
         *
         * Note: putting PCI core on warm reset on PCI-E cards
         * results card to hang and always return 0xffff... so
         * we ignore that flag for PCI-E cards. On PCI cards
         * this flag gets cleared after 64 PCI clocks.
         */
        bus_flags = (pdev && pci_is_pcie(pdev)) ? 0 : AR5K_RESET_CTL_PCI;

        if (ah->ah_version == AR5K_AR5210) {
                ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
                        AR5K_RESET_CTL_MAC | AR5K_RESET_CTL_DMA |
                        AR5K_RESET_CTL_PHY | AR5K_RESET_CTL_PCI);
                        usleep_range(2000, 2500);
        } else {
                if (ath5k_get_bus_type(ah) == ATH_AHB)
                        ret = ath5k_hw_wisoc_reset(ah, AR5K_RESET_CTL_PCU |
                                AR5K_RESET_CTL_BASEBAND);
                else
                        ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
                                AR5K_RESET_CTL_BASEBAND | bus_flags);
        }

        if (ret) {
                ATH5K_ERR(ah, "failed to reset the MAC Chip\n");
                return -EIO;
        }

        /* ...wakeup again!...*/
        ret = ath5k_hw_set_power_mode(ah, AR5K_PM_AWAKE, true, 0);
        if (ret) {
                ATH5K_ERR(ah, "failed to resume the MAC Chip\n");
                return ret;
        }

        /* ...reset configuration register on Wisoc ...
         * ...clear reset control register and pull device out of
         * warm reset on others */
        if (ath5k_get_bus_type(ah) == ATH_AHB)
                ret = ath5k_hw_wisoc_reset(ah, 0);
        else
                ret = ath5k_hw_nic_reset(ah, 0);

        if (ret) {
                ATH5K_ERR(ah, "failed to warm reset the MAC Chip\n");
                return -EIO;
        }

        /* On initialization skip PLL programming since we don't have
         * a channel / mode set yet */
        if (!channel)
                return 0;

        if (ah->ah_version != AR5K_AR5210) {
                /*
                 * Get channel mode flags
                 */

                if (ah->ah_radio >= AR5K_RF5112) {
                        mode = AR5K_PHY_MODE_RAD_RF5112;
                        clock = AR5K_PHY_PLL_RF5112;
                } else {
                        mode = AR5K_PHY_MODE_RAD_RF5111;        /*Zero*/
                        clock = AR5K_PHY_PLL_RF5111;            /*Zero*/
                }

                if (channel->band == IEEE80211_BAND_2GHZ) {
                        mode |= AR5K_PHY_MODE_FREQ_2GHZ;
                        clock |= AR5K_PHY_PLL_44MHZ;

                        if (channel->hw_value == AR5K_MODE_11B) {
                                mode |= AR5K_PHY_MODE_MOD_CCK;
                        } else {
                                /* XXX Dynamic OFDM/CCK is not supported by the
                                 * AR5211 so we set MOD_OFDM for plain g (no
                                 * CCK headers) operation. We need to test
                                 * this, 5211 might support ofdm-only g after
                                 * all, there are also initial register values
                                 * in the code for g mode (see initvals.c).
                                 */
                                if (ah->ah_version == AR5K_AR5211)
                                        mode |= AR5K_PHY_MODE_MOD_OFDM;
                                else
                                        mode |= AR5K_PHY_MODE_MOD_DYN;
                        }
                } else if (channel->band == IEEE80211_BAND_5GHZ) {
                        mode |= (AR5K_PHY_MODE_FREQ_5GHZ |
                                 AR5K_PHY_MODE_MOD_OFDM);

                        /* Different PLL setting for 5413 */
                        if (ah->ah_radio == AR5K_RF5413)
                                clock = AR5K_PHY_PLL_40MHZ_5413;
                        else
                                clock |= AR5K_PHY_PLL_40MHZ;
                } else {
                        ATH5K_ERR(ah, "invalid radio frequency mode\n");
                        return -EINVAL;
                }

                /*XXX: Can bwmode be used with dynamic mode ?
                 * (I don't think it supports 44MHz) */
                /* On 2425 initvals TURBO_SHORT is not present */
                if (ah->ah_bwmode == AR5K_BWMODE_40MHZ) {
                        turbo = AR5K_PHY_TURBO_MODE;
                        if (ah->ah_radio != AR5K_RF2425)
                                turbo |= AR5K_PHY_TURBO_SHORT;
                } else if (ah->ah_bwmode != AR5K_BWMODE_DEFAULT) {
                        if (ah->ah_radio == AR5K_RF5413) {
                                mode |= (ah->ah_bwmode == AR5K_BWMODE_10MHZ) ?
                                        AR5K_PHY_MODE_HALF_RATE :
                                        AR5K_PHY_MODE_QUARTER_RATE;
                        } else if (ah->ah_version == AR5K_AR5212) {
                                clock |= (ah->ah_bwmode == AR5K_BWMODE_10MHZ) ?
                                        AR5K_PHY_PLL_HALF_RATE :
                                        AR5K_PHY_PLL_QUARTER_RATE;
                        }
                }

        } else { /* Reset the device */

                /* ...enable Atheros turbo mode if requested */
                if (ah->ah_bwmode == AR5K_BWMODE_40MHZ)
                        ath5k_hw_reg_write(ah, AR5K_PHY_TURBO_MODE,
                                        AR5K_PHY_TURBO);
        }

        if (ah->ah_version != AR5K_AR5210) {

                /* ...update PLL if needed */
                if (ath5k_hw_reg_read(ah, AR5K_PHY_PLL) != clock) {
                        ath5k_hw_reg_write(ah, clock, AR5K_PHY_PLL);
                        usleep_range(300, 350);
                }

                /* ...set the PHY operating mode */
                ath5k_hw_reg_write(ah, mode, AR5K_PHY_MODE);
                ath5k_hw_reg_write(ah, turbo, AR5K_PHY_TURBO);
        }

        return 0;
}


/**************************************\
* Post-initvals register modifications *
\**************************************/

/**
 * ath5k_hw_tweak_initval_settings() - Tweak initial settings
 * @ah: The &struct ath5k_hw
 * @channel: The &struct ieee80211_channel
 *
 * Some settings are not handled on initvals, e.g. bwmode
 * settings, some phy settings, workarounds etc that in general
 * don't fit anywhere else or are too small to introduce a separate
 * function for each one. So we have this function to handle
 * them all during reset and complete card's initialization.
 */
static void
ath5k_hw_tweak_initval_settings(struct ath5k_hw *ah,
                                struct ieee80211_channel *channel)
{
        if (ah->ah_version == AR5K_AR5212 &&
            ah->ah_phy_revision >= AR5K_SREV_PHY_5212A) {

                /* Setup ADC control */
                ath5k_hw_reg_write(ah,
                                (AR5K_REG_SM(2,
                                AR5K_PHY_ADC_CTL_INBUFGAIN_OFF) |
                                AR5K_REG_SM(2,
                                AR5K_PHY_ADC_CTL_INBUFGAIN_ON) |
                                AR5K_PHY_ADC_CTL_PWD_DAC_OFF |
                                AR5K_PHY_ADC_CTL_PWD_ADC_OFF),
                                AR5K_PHY_ADC_CTL);



                /* Disable barker RSSI threshold */
                AR5K_REG_DISABLE_BITS(ah, AR5K_PHY_DAG_CCK_CTL,
                                AR5K_PHY_DAG_CCK_CTL_EN_RSSI_THR);

                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_DAG_CCK_CTL,
                        AR5K_PHY_DAG_CCK_CTL_RSSI_THR, 2);

                /* Set the mute mask */
                ath5k_hw_reg_write(ah, 0x0000000f, AR5K_SEQ_MASK);
        }

        /* Clear PHY_BLUETOOTH to allow RX_CLEAR line debug */
        if (ah->ah_phy_revision >= AR5K_SREV_PHY_5212B)
                ath5k_hw_reg_write(ah, 0, AR5K_PHY_BLUETOOTH);

        /* Enable DCU double buffering */
        if (ah->ah_phy_revision > AR5K_SREV_PHY_5212B)
                AR5K_REG_DISABLE_BITS(ah, AR5K_TXCFG,
                                AR5K_TXCFG_DCU_DBL_BUF_DIS);

        /* Set fast ADC */
        if ((ah->ah_radio == AR5K_RF5413) ||
                (ah->ah_radio == AR5K_RF2317) ||
                (ah->ah_mac_version == (AR5K_SREV_AR2417 >> 4))) {
                u32 fast_adc = true;

                if (channel->center_freq == 2462 ||
                channel->center_freq == 2467)
                        fast_adc = 0;

                /* Only update if needed */
                if (ath5k_hw_reg_read(ah, AR5K_PHY_FAST_ADC) != fast_adc)
                                ath5k_hw_reg_write(ah, fast_adc,
                                                AR5K_PHY_FAST_ADC);
        }

        /* Fix for first revision of the RF5112 RF chipset */
        if (ah->ah_radio == AR5K_RF5112 &&
                        ah->ah_radio_5ghz_revision <
                        AR5K_SREV_RAD_5112A) {
                u32 data;
                ath5k_hw_reg_write(ah, AR5K_PHY_CCKTXCTL_WORLD,
                                AR5K_PHY_CCKTXCTL);
                if (channel->band == IEEE80211_BAND_5GHZ)
                        data = 0xffb81020;
                else
                        data = 0xffb80d20;
                ath5k_hw_reg_write(ah, data, AR5K_PHY_FRAME_CTL);
        }

        if (ah->ah_mac_srev < AR5K_SREV_AR5211) {
                /* Clear QCU/DCU clock gating register */
                ath5k_hw_reg_write(ah, 0, AR5K_QCUDCU_CLKGT);
                /* Set DAC/ADC delays */
                ath5k_hw_reg_write(ah, AR5K_PHY_SCAL_32MHZ_5311,
                                                AR5K_PHY_SCAL);
                /* Enable PCU FIFO corruption ECO */
                AR5K_REG_ENABLE_BITS(ah, AR5K_DIAG_SW_5211,
                                        AR5K_DIAG_SW_ECO_ENABLE);
        }

        if (ah->ah_bwmode) {
                /* Increase PHY switch and AGC settling time
                 * on turbo mode (ath5k_hw_commit_eeprom_settings
                 * will override settling time if available) */
                if (ah->ah_bwmode == AR5K_BWMODE_40MHZ) {

                        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SETTLING,
                                                AR5K_PHY_SETTLING_AGC,
                                                AR5K_AGC_SETTLING_TURBO);

                        /* XXX: Initvals indicate we only increase
                         * switch time on AR5212, 5211 and 5210
                         * only change agc time (bug?) */
                        if (ah->ah_version == AR5K_AR5212)
                                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SETTLING,
                                                AR5K_PHY_SETTLING_SWITCH,
                                                AR5K_SWITCH_SETTLING_TURBO);

                        if (ah->ah_version == AR5K_AR5210) {
                                /* Set Frame Control Register */
                                ath5k_hw_reg_write(ah,
                                        (AR5K_PHY_FRAME_CTL_INI |
                                        AR5K_PHY_TURBO_MODE |
                                        AR5K_PHY_TURBO_SHORT | 0x2020),
                                        AR5K_PHY_FRAME_CTL_5210);
                        }
                /* On 5413 PHY force window length for half/quarter rate*/
                } else if ((ah->ah_mac_srev >= AR5K_SREV_AR5424) &&
                (ah->ah_mac_srev <= AR5K_SREV_AR5414)) {
                        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_FRAME_CTL_5211,
                                                AR5K_PHY_FRAME_CTL_WIN_LEN,
                                                3);
                }
        } else if (ah->ah_version == AR5K_AR5210) {
                /* Set Frame Control Register for normal operation */
                ath5k_hw_reg_write(ah, (AR5K_PHY_FRAME_CTL_INI | 0x1020),
                                                AR5K_PHY_FRAME_CTL_5210);
        }
}

/**
 * ath5k_hw_commit_eeprom_settings() - Commit settings from EEPROM
 * @ah: The &struct ath5k_hw
 * @channel: The &struct ieee80211_channel
 *
 * Use settings stored on EEPROM to properly initialize the card
 * based on various infos and per-mode calibration data.
 */
static void
ath5k_hw_commit_eeprom_settings(struct ath5k_hw *ah,
                struct ieee80211_channel *channel)
{
        struct ath5k_eeprom_info *ee = &ah->ah_capabilities.cap_eeprom;
        s16 cck_ofdm_pwr_delta;
        u8 ee_mode;

        /* TODO: Add support for AR5210 EEPROM */
        if (ah->ah_version == AR5K_AR5210)
                return;

        ee_mode = ath5k_eeprom_mode_from_channel(ah, channel);

        /* Adjust power delta for channel 14 */
        if (channel->center_freq == 2484)
                cck_ofdm_pwr_delta =
                        ((ee->ee_cck_ofdm_power_delta -
                        ee->ee_scaled_cck_delta) * 2) / 10;
        else
                cck_ofdm_pwr_delta =
                        (ee->ee_cck_ofdm_power_delta * 2) / 10;

        /* Set CCK to OFDM power delta on tx power
         * adjustment register */
        if (ah->ah_phy_revision >= AR5K_SREV_PHY_5212A) {

                if (channel->hw_value == AR5K_MODE_11G)
                        ath5k_hw_reg_write(ah,
                        AR5K_REG_SM((ee->ee_cck_ofdm_gain_delta * -1),
                                AR5K_PHY_TX_PWR_ADJ_CCK_GAIN_DELTA) |
                        AR5K_REG_SM((cck_ofdm_pwr_delta * -1),
                                AR5K_PHY_TX_PWR_ADJ_CCK_PCDAC_INDEX),
                                AR5K_PHY_TX_PWR_ADJ);
                else
                        ath5k_hw_reg_write(ah, 0, AR5K_PHY_TX_PWR_ADJ);
        } else {
                /* For older revs we scale power on sw during tx power
                 * setup */
                ah->ah_txpower.txp_cck_ofdm_pwr_delta = cck_ofdm_pwr_delta;
                ah->ah_txpower.txp_cck_ofdm_gainf_delta =
                                                ee->ee_cck_ofdm_gain_delta;
        }

        /* XXX: necessary here? is called from ath5k_hw_set_antenna_mode()
         * too */
        ath5k_hw_set_antenna_switch(ah, ee_mode);

        /* Noise floor threshold */
        ath5k_hw_reg_write(ah,
                AR5K_PHY_NF_SVAL(ee->ee_noise_floor_thr[ee_mode]),
                AR5K_PHY_NFTHRES);

        if ((ah->ah_bwmode == AR5K_BWMODE_40MHZ) &&
        (ah->ah_ee_version >= AR5K_EEPROM_VERSION_5_0)) {
                /* Switch settling time (Turbo) */
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SETTLING,
                                AR5K_PHY_SETTLING_SWITCH,
                                ee->ee_switch_settling_turbo[ee_mode]);

                /* Tx/Rx attenuation (Turbo) */
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_GAIN,
                                AR5K_PHY_GAIN_TXRX_ATTEN,
                                ee->ee_atn_tx_rx_turbo[ee_mode]);

                /* ADC/PGA desired size (Turbo) */
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_DESIRED_SIZE,
                                AR5K_PHY_DESIRED_SIZE_ADC,
                                ee->ee_adc_desired_size_turbo[ee_mode]);

                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_DESIRED_SIZE,
                                AR5K_PHY_DESIRED_SIZE_PGA,
                                ee->ee_pga_desired_size_turbo[ee_mode]);

                /* Tx/Rx margin (Turbo) */
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_GAIN_2GHZ,
                                AR5K_PHY_GAIN_2GHZ_MARGIN_TXRX,
                                ee->ee_margin_tx_rx_turbo[ee_mode]);

        } else {
                /* Switch settling time */
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SETTLING,
                                AR5K_PHY_SETTLING_SWITCH,
                                ee->ee_switch_settling[ee_mode]);

                /* Tx/Rx attenuation */
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_GAIN,
                                AR5K_PHY_GAIN_TXRX_ATTEN,
                                ee->ee_atn_tx_rx[ee_mode]);

                /* ADC/PGA desired size */
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_DESIRED_SIZE,
                                AR5K_PHY_DESIRED_SIZE_ADC,
                                ee->ee_adc_desired_size[ee_mode]);

                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_DESIRED_SIZE,
                                AR5K_PHY_DESIRED_SIZE_PGA,
                                ee->ee_pga_desired_size[ee_mode]);

                /* Tx/Rx margin */
                if (ah->ah_ee_version >= AR5K_EEPROM_VERSION_4_1)
                        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_GAIN_2GHZ,
                                AR5K_PHY_GAIN_2GHZ_MARGIN_TXRX,
                                ee->ee_margin_tx_rx[ee_mode]);
        }

        /* XPA delays */
        ath5k_hw_reg_write(ah,
                (ee->ee_tx_end2xpa_disable[ee_mode] << 24) |
                (ee->ee_tx_end2xpa_disable[ee_mode] << 16) |
                (ee->ee_tx_frm2xpa_enable[ee_mode] << 8) |
                (ee->ee_tx_frm2xpa_enable[ee_mode]), AR5K_PHY_RF_CTL4);

        /* XLNA delay */
        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_RF_CTL3,
                        AR5K_PHY_RF_CTL3_TXE2XLNA_ON,
                        ee->ee_tx_end2xlna_enable[ee_mode]);

        /* Thresh64 (ANI) */
        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_NF,
                        AR5K_PHY_NF_THRESH62,
                        ee->ee_thr_62[ee_mode]);

        /* False detect backoff for channels
         * that have spur noise. Write the new
         * cyclic power RSSI threshold. */
        if (ath5k_hw_chan_has_spur_noise(ah, channel))
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_OFDM_SELFCORR,
                                AR5K_PHY_OFDM_SELFCORR_CYPWR_THR1,
                                AR5K_INIT_CYCRSSI_THR1 +
                                ee->ee_false_detect[ee_mode]);
        else
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_OFDM_SELFCORR,
                                AR5K_PHY_OFDM_SELFCORR_CYPWR_THR1,
                                AR5K_INIT_CYCRSSI_THR1);

        /* I/Q correction (set enable bit last to match HAL sources) */
        /* TODO: Per channel i/q infos ? */
        if (ah->ah_ee_version >= AR5K_EEPROM_VERSION_4_0) {
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_IQ, AR5K_PHY_IQ_CORR_Q_I_COFF,
                            ee->ee_i_cal[ee_mode]);
                AR5K_REG_WRITE_BITS(ah, AR5K_PHY_IQ, AR5K_PHY_IQ_CORR_Q_Q_COFF,
                            ee->ee_q_cal[ee_mode]);
                AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_IQ, AR5K_PHY_IQ_CORR_ENABLE);
        }

        /* Heavy clipping -disable for now */
        if (ah->ah_ee_version >= AR5K_EEPROM_VERSION_5_1)
                ath5k_hw_reg_write(ah, 0, AR5K_PHY_HEAVY_CLIP_ENABLE);
}


/*********************\
* Main reset function *
\*********************/

/**
 * ath5k_hw_reset() - The main reset function
 * @ah: The &struct ath5k_hw
 * @op_mode: One of enum nl80211_iftype
 * @channel: The &struct ieee80211_channel
 * @fast: Enable fast channel switching
 * @skip_pcu: Skip pcu initialization
 *
 * This is the function we call each time we want to (re)initialize the
 * card and pass new settings to hw. We also call it when hw runs into
 * trouble to make it come back to a working state.
 *
 * Returns 0 on success, -EINVAL on false op_mode or channel infos, or -EIO
 * on failure.
 */
int
ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
                struct ieee80211_channel *channel, bool fast, bool skip_pcu)
{
        u32 s_seq[10], s_led[3], tsf_up, tsf_lo;
        u8 mode;
        int i, ret;

        tsf_up = 0;
        tsf_lo = 0;
        mode = 0;

        /*
         * Sanity check for fast flag
         * Fast channel change only available
         * on AR2413/AR5413.
         */
        if (fast && (ah->ah_radio != AR5K_RF2413) &&
        (ah->ah_radio != AR5K_RF5413))
                fast = false;

        /* Disable sleep clock operation
         * to avoid register access delay on certain
         * PHY registers */
        if (ah->ah_version == AR5K_AR5212)
                ath5k_hw_set_sleep_clock(ah, false);

        /*
         * Stop PCU
         */
        ath5k_hw_stop_rx_pcu(ah);

        /*
         * Stop DMA
         *
         * Note: If DMA didn't stop continue
         * since only a reset will fix it.
         */
        ret = ath5k_hw_dma_stop(ah);

        /* RF Bus grant won't work if we have pending
         * frames */
        if (ret && fast) {
                ATH5K_DBG(ah, ATH5K_DEBUG_RESET,
                        "DMA didn't stop, falling back to normal reset\n");
                fast = false;
                /* Non fatal, just continue with
                 * normal reset */
                ret = 0;
        }

        mode = channel->hw_value;
        switch (mode) {
        case AR5K_MODE_11A:
                break;
        case AR5K_MODE_11G:
                if (ah->ah_version <= AR5K_AR5211) {
                        ATH5K_ERR(ah,
                                "G mode not available on 5210/5211");
                        return -EINVAL;
                }
                break;
        case AR5K_MODE_11B:
                if (ah->ah_version < AR5K_AR5211) {
                        ATH5K_ERR(ah,
                                "B mode not available on 5210");
                        return -EINVAL;
                }
                break;
        default:
                ATH5K_ERR(ah,
                        "invalid channel: %d\n", channel->center_freq);
                return -EINVAL;
        }

        /*
         * If driver requested fast channel change and DMA has stopped
         * go on. If it fails continue with a normal reset.
         */
        if (fast) {
                ret = ath5k_hw_phy_init(ah, channel, mode, true);
                if (ret) {
                        ATH5K_DBG(ah, ATH5K_DEBUG_RESET,
                                "fast chan change failed, falling back to normal reset\n");
                        /* Non fatal, can happen eg.
                         * on mode change */
                        ret = 0;
                } else {
                        ATH5K_DBG(ah, ATH5K_DEBUG_RESET,
                                "fast chan change successful\n");
                        return 0;
                }
        }

        /*
         * Save some registers before a reset
         */
        if (ah->ah_version != AR5K_AR5210) {
                /*
                 * Save frame sequence count
                 * For revs. after Oahu, only save
                 * seq num for DCU 0 (Global seq num)
                 */
                if (ah->ah_mac_srev < AR5K_SREV_AR5211) {

                        for (i = 0; i < 10; i++)
                                s_seq[i] = ath5k_hw_reg_read(ah,
                                        AR5K_QUEUE_DCU_SEQNUM(i));

                } else {
                        s_seq[0] = ath5k_hw_reg_read(ah,
                                        AR5K_QUEUE_DCU_SEQNUM(0));
                }

                /* TSF accelerates on AR5211 during reset
                 * As a workaround save it here and restore
                 * it later so that it's back in time after
                 * reset. This way it'll get re-synced on the
                 * next beacon without breaking ad-hoc.
                 *
                 * On AR5212 TSF is almost preserved across a
                 * reset so it stays back in time anyway and
                 * we don't have to save/restore it.
                 *
                 * XXX: Since this breaks power saving we have
                 * to disable power saving until we receive the
                 * next beacon, so we can resync beacon timers */
                if (ah->ah_version == AR5K_AR5211) {
                        tsf_up = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
                        tsf_lo = ath5k_hw_reg_read(ah, AR5K_TSF_L32);
                }
        }


        /*GPIOs*/
        s_led[0] = ath5k_hw_reg_read(ah, AR5K_PCICFG) &
                                        AR5K_PCICFG_LEDSTATE;
        s_led[1] = ath5k_hw_reg_read(ah, AR5K_GPIOCR);
        s_led[2] = ath5k_hw_reg_read(ah, AR5K_GPIODO);


        /*
         * Since we are going to write rf buffer
         * check if we have any pending gain_F
         * optimization settings
         */
        if (ah->ah_version == AR5K_AR5212 &&
        (ah->ah_radio <= AR5K_RF5112)) {
                if (!fast && ah->ah_rf_banks != NULL)
                                ath5k_hw_gainf_calibrate(ah);
        }

        /* Wakeup the device */
        ret = ath5k_hw_nic_wakeup(ah, channel);
        if (ret)
                return ret;

        /* PHY access enable */
        if (ah->ah_mac_srev >= AR5K_SREV_AR5211)
                ath5k_hw_reg_write(ah, AR5K_PHY_SHIFT_5GHZ, AR5K_PHY(0));
        else
                ath5k_hw_reg_write(ah, AR5K_PHY_SHIFT_5GHZ | 0x40,
                                                        AR5K_PHY(0));

        /* Write initial settings */
        ret = ath5k_hw_write_initvals(ah, mode, skip_pcu);
        if (ret)
                return ret;

        /* Initialize core clock settings */
        ath5k_hw_init_core_clock(ah);

        /*
         * Tweak initval settings for revised
         * chipsets and add some more config
         * bits
         */
        ath5k_hw_tweak_initval_settings(ah, channel);

        /* Commit values from EEPROM */
        ath5k_hw_commit_eeprom_settings(ah, channel);


        /*
         * Restore saved values
         */

        /* Seqnum, TSF */
        if (ah->ah_version != AR5K_AR5210) {
                if (ah->ah_mac_srev < AR5K_SREV_AR5211) {
                        for (i = 0; i < 10; i++)
                                ath5k_hw_reg_write(ah, s_seq[i],
                                        AR5K_QUEUE_DCU_SEQNUM(i));
                } else {
                        ath5k_hw_reg_write(ah, s_seq[0],
                                AR5K_QUEUE_DCU_SEQNUM(0));
                }

                if (ah->ah_version == AR5K_AR5211) {
                        ath5k_hw_reg_write(ah, tsf_up, AR5K_TSF_U32);
                        ath5k_hw_reg_write(ah, tsf_lo, AR5K_TSF_L32);
                }
        }

        /* Ledstate */
        AR5K_REG_ENABLE_BITS(ah, AR5K_PCICFG, s_led[0]);

        /* Gpio settings */
        ath5k_hw_reg_write(ah, s_led[1], AR5K_GPIOCR);
        ath5k_hw_reg_write(ah, s_led[2], AR5K_GPIODO);

        /*
         * Initialize PCU
         */
        ath5k_hw_pcu_init(ah, op_mode);

        /*
         * Initialize PHY
         */
        ret = ath5k_hw_phy_init(ah, channel, mode, false);
        if (ret) {
                ATH5K_ERR(ah,
                        "failed to initialize PHY (%i) !\n", ret);
                return ret;
        }

        /*
         * Configure QCUs/DCUs
         */
        ret = ath5k_hw_init_queues(ah);
        if (ret)
                return ret;


        /*
         * Initialize DMA/Interrupts
         */
        ath5k_hw_dma_init(ah);


        /*
         * Enable 32KHz clock function for AR5212+ chips
         * Set clocks to 32KHz operation and use an
         * external 32KHz crystal when sleeping if one
         * exists.
         * Disabled by default because it is also disabled in
         * other drivers and it is known to cause stability
         * issues on some devices
         */
        if (ah->ah_use_32khz_clock && ah->ah_version == AR5K_AR5212 &&
            op_mode != NL80211_IFTYPE_AP)
                ath5k_hw_set_sleep_clock(ah, true);

        /*
         * Disable beacons and reset the TSF
         */
        AR5K_REG_DISABLE_BITS(ah, AR5K_BEACON, AR5K_BEACON_ENABLE);
        ath5k_hw_reset_tsf(ah);
        return 0;
}