/*
 * Intel Wireless Multicomm 3200 WiFi driver
 *
 * Copyright (C) 2009 Intel Corporation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Intel Corporation <ilw@linux.intel.com>
 * Samuel Ortiz <samuel.ortiz@intel.com>
 * Zhu Yi <yi.zhu@intel.com>
 *
 */

/*
 * Hardware Abstraction Layer for iwm.
 *
 * This file mostly defines an abstraction API for
 * sending various commands to the target.
 *
 * We have 2 types of commands: wifi and non-wifi ones.
 *
 * - wifi commands:
 *   They are used for sending LMAC and UMAC commands,
 *   and thus are the most commonly used ones.
 *   There are 2 different wifi command types, the regular
 *   one and the LMAC one. The former is used to send
 *   UMAC commands (see UMAC_CMD_OPCODE_* from umac.h)
 *   while the latter is used for sending commands to the
 *   LMAC. If you look at LMAC commands you'll se that they
 *   are actually regular iwlwifi target commands encapsulated
 *   into a special UMAC command called UMAC passthrough.
 *   This is due to the fact the host talks exclusively
 *   to the UMAC and so there needs to be a special UMAC
 *   command for talking to the LMAC.
 *   This is how a wifi command is layed out:
 *    ------------------------
 *   | iwm_udma_out_wifi_hdr  |
 *    ------------------------
 *   | SW meta_data (32 bits) |
 *    ------------------------
 *   | iwm_dev_cmd_hdr        |
 *    ------------------------
 *   | payload                |
 *   | ....                   |
 *
 * - non-wifi, or general commands:
 *   Those commands are handled by the device's bootrom,
 *   and are typically sent when the UMAC and the LMAC
 *   are not yet available.
 *    *   This is how a non-wifi command is layed out:
 *    ---------------------------
 *   | iwm_udma_out_nonwifi_hdr  |
 *    ---------------------------
 *   | payload                   |
 *   | ....                      |

 *
 * All the commands start with a UDMA header, which is
 * basically a 32 bits field. The 4 LSB there define
 * an opcode that allows the target to differentiate
 * between wifi (opcode is 0xf) and non-wifi commands
 * (opcode is [0..0xe]).
 *
 * When a command (wifi or non-wifi) is supposed to receive
 * an answer, we queue the command buffer. When we do receive
 * a command response from the UMAC, we go through the list
 * of pending command, and pass both the command and the answer
 * to the rx handler. Each command is sent with a unique
 * sequence id, and the answer is sent with the same one. This
 * is how we're supposed to match an answer with its command.
 * See rx.c:iwm_rx_handle_[non]wifi() and iwm_get_pending_[non]wifi()
 * for the implementation details.
 */
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/slab.h>

#include "iwm.h"
#include "bus.h"
#include "hal.h"
#include "umac.h"
#include "debug.h"
#include "trace.h"

static int iwm_nonwifi_cmd_init(struct iwm_priv *iwm,
                                struct iwm_nonwifi_cmd *cmd,
                                struct iwm_udma_nonwifi_cmd *udma_cmd)
{
        INIT_LIST_HEAD(&cmd->pending);

        spin_lock(&iwm->cmd_lock);

        cmd->resp_received = 0;

        cmd->seq_num = iwm->nonwifi_seq_num;
        udma_cmd->seq_num = cpu_to_le16(cmd->seq_num);

        iwm->nonwifi_seq_num++;
        iwm->nonwifi_seq_num %= UMAC_NONWIFI_SEQ_NUM_MAX;

        if (udma_cmd->resp)
                list_add_tail(&cmd->pending, &iwm->nonwifi_pending_cmd);

        spin_unlock(&iwm->cmd_lock);

        cmd->buf.start = cmd->buf.payload;
        cmd->buf.len = 0;

        memcpy(&cmd->udma_cmd, udma_cmd, sizeof(*udma_cmd));

        return cmd->seq_num;
}

u16 iwm_alloc_wifi_cmd_seq(struct iwm_priv *iwm)
{
        u16 seq_num = iwm->wifi_seq_num;

        iwm->wifi_seq_num++;
        iwm->wifi_seq_num %= UMAC_WIFI_SEQ_NUM_MAX;

        return seq_num;
}

static void iwm_wifi_cmd_init(struct iwm_priv *iwm,
                              struct iwm_wifi_cmd *cmd,
                              struct iwm_udma_wifi_cmd *udma_cmd,
                              struct iwm_umac_cmd *umac_cmd,
                              struct iwm_lmac_cmd *lmac_cmd,
                              u16 payload_size)
{
        INIT_LIST_HEAD(&cmd->pending);

        spin_lock(&iwm->cmd_lock);

        cmd->seq_num = iwm_alloc_wifi_cmd_seq(iwm);
        umac_cmd->seq_num = cpu_to_le16(cmd->seq_num);

        if (umac_cmd->resp)
                list_add_tail(&cmd->pending, &iwm->wifi_pending_cmd);

        spin_unlock(&iwm->cmd_lock);

        cmd->buf.start = cmd->buf.payload;
        cmd->buf.len = 0;

        if (lmac_cmd) {
                cmd->buf.start -= sizeof(struct iwm_lmac_hdr);

                lmac_cmd->seq_num = cpu_to_le16(cmd->seq_num);
                lmac_cmd->count = cpu_to_le16(payload_size);

                memcpy(&cmd->lmac_cmd, lmac_cmd, sizeof(*lmac_cmd));

                umac_cmd->count = cpu_to_le16(sizeof(struct iwm_lmac_hdr));
        } else
                umac_cmd->count = 0;

        umac_cmd->count = cpu_to_le16(payload_size +
                                      le16_to_cpu(umac_cmd->count));
        udma_cmd->count = cpu_to_le16(sizeof(struct iwm_umac_fw_cmd_hdr) +
                                      le16_to_cpu(umac_cmd->count));

        memcpy(&cmd->udma_cmd, udma_cmd, sizeof(*udma_cmd));
        memcpy(&cmd->umac_cmd, umac_cmd, sizeof(*umac_cmd));
}

void iwm_cmd_flush(struct iwm_priv *iwm)
{
        struct iwm_wifi_cmd *wcmd, *wnext;
        struct iwm_nonwifi_cmd *nwcmd, *nwnext;

        list_for_each_entry_safe(wcmd, wnext, &iwm->wifi_pending_cmd, pending) {
                list_del(&wcmd->pending);
                kfree(wcmd);
        }

        list_for_each_entry_safe(nwcmd, nwnext, &iwm->nonwifi_pending_cmd,
                                 pending) {
                list_del(&nwcmd->pending);
                kfree(nwcmd);
        }
}

struct iwm_wifi_cmd *iwm_get_pending_wifi_cmd(struct iwm_priv *iwm, u16 seq_num)
{
        struct iwm_wifi_cmd *cmd;

        list_for_each_entry(cmd, &iwm->wifi_pending_cmd, pending)
                if (cmd->seq_num == seq_num) {
                        list_del(&cmd->pending);
                        return cmd;
                }

        return NULL;
}

struct iwm_nonwifi_cmd *iwm_get_pending_nonwifi_cmd(struct iwm_priv *iwm,
                                                    u8 seq_num, u8 cmd_opcode)
{
        struct iwm_nonwifi_cmd *cmd;

        list_for_each_entry(cmd, &iwm->nonwifi_pending_cmd, pending)
                if ((cmd->seq_num == seq_num) &&
                    (cmd->udma_cmd.opcode == cmd_opcode) &&
                    (cmd->resp_received)) {
                        list_del(&cmd->pending);
                        return cmd;
                }

        return NULL;
}

static void iwm_build_udma_nonwifi_hdr(struct iwm_priv *iwm,
                                       struct iwm_udma_out_nonwifi_hdr *hdr,
                                       struct iwm_udma_nonwifi_cmd *cmd)
{
        memset(hdr, 0, sizeof(*hdr));

        SET_VAL32(hdr->cmd, UMAC_HDI_OUT_CMD_OPCODE, cmd->opcode);
        SET_VAL32(hdr->cmd, UDMA_HDI_OUT_NW_CMD_RESP, cmd->resp);
        SET_VAL32(hdr->cmd, UMAC_HDI_OUT_CMD_EOT, 1);
        SET_VAL32(hdr->cmd, UDMA_HDI_OUT_NW_CMD_HANDLE_BY_HW,
                  cmd->handle_by_hw);
        SET_VAL32(hdr->cmd, UMAC_HDI_OUT_CMD_SIGNATURE, UMAC_HDI_OUT_SIGNATURE);
        SET_VAL32(hdr->cmd, UDMA_HDI_OUT_CMD_NON_WIFI_HW_SEQ_NUM,
                  le16_to_cpu(cmd->seq_num));

        hdr->addr = cmd->addr;
        hdr->op1_sz = cmd->op1_sz;
        hdr->op2 = cmd->op2;
}

static int iwm_send_udma_nonwifi_cmd(struct iwm_priv *iwm,
                                     struct iwm_nonwifi_cmd *cmd)
{
        struct iwm_udma_out_nonwifi_hdr *udma_hdr;
        struct iwm_nonwifi_cmd_buff *buf;
        struct iwm_udma_nonwifi_cmd *udma_cmd = &cmd->udma_cmd;

        buf = &cmd->buf;

        buf->start -= sizeof(struct iwm_umac_nonwifi_out_hdr);
        buf->len += sizeof(struct iwm_umac_nonwifi_out_hdr);

        udma_hdr = (struct iwm_udma_out_nonwifi_hdr *)(buf->start);

        iwm_build_udma_nonwifi_hdr(iwm, udma_hdr, udma_cmd);

        IWM_DBG_CMD(iwm, DBG,
                    "Send UDMA nonwifi cmd: opcode = 0x%x, resp = 0x%x, "
                    "hw = 0x%x, seqnum = %d, addr = 0x%x, op1_sz = 0x%x, "
                    "op2 = 0x%x\n", udma_cmd->opcode, udma_cmd->resp,
                    udma_cmd->handle_by_hw, cmd->seq_num, udma_cmd->addr,
                    udma_cmd->op1_sz, udma_cmd->op2);

        trace_iwm_tx_nonwifi_cmd(iwm, udma_hdr);
        return iwm_bus_send_chunk(iwm, buf->start, buf->len);
}

void iwm_udma_wifi_hdr_set_eop(struct iwm_priv *iwm, u8 *buf, u8 eop)
{
        struct iwm_udma_out_wifi_hdr *hdr = (struct iwm_udma_out_wifi_hdr *)buf;

        SET_VAL32(hdr->cmd, UMAC_HDI_OUT_CMD_EOT, eop);
}

void iwm_build_udma_wifi_hdr(struct iwm_priv *iwm,
                             struct iwm_udma_out_wifi_hdr *hdr,
                             struct iwm_udma_wifi_cmd *cmd)
{
        memset(hdr, 0, sizeof(*hdr));

        SET_VAL32(hdr->cmd, UMAC_HDI_OUT_CMD_OPCODE, UMAC_HDI_OUT_OPCODE_WIFI);
        SET_VAL32(hdr->cmd, UMAC_HDI_OUT_CMD_EOT, cmd->eop);
        SET_VAL32(hdr->cmd, UMAC_HDI_OUT_CMD_SIGNATURE, UMAC_HDI_OUT_SIGNATURE);

        SET_VAL32(hdr->meta_data, UMAC_HDI_OUT_BYTE_COUNT,
                  le16_to_cpu(cmd->count));
        SET_VAL32(hdr->meta_data, UMAC_HDI_OUT_CREDIT_GRP, cmd->credit_group);
        SET_VAL32(hdr->meta_data, UMAC_HDI_OUT_RATID, cmd->ra_tid);
        SET_VAL32(hdr->meta_data, UMAC_HDI_OUT_LMAC_OFFSET, cmd->lmac_offset);
}

void iwm_build_umac_hdr(struct iwm_priv *iwm,
                        struct iwm_umac_fw_cmd_hdr *hdr,
                        struct iwm_umac_cmd *cmd)
{
        memset(hdr, 0, sizeof(*hdr));

        SET_VAL32(hdr->meta_data, UMAC_FW_CMD_BYTE_COUNT,
                  le16_to_cpu(cmd->count));
        SET_VAL32(hdr->meta_data, UMAC_FW_CMD_TX_STA_COLOR, cmd->color);
        SET_VAL8(hdr->cmd.flags, UMAC_DEV_CMD_FLAGS_RESP_REQ, cmd->resp);

        hdr->cmd.cmd = cmd->id;
        hdr->cmd.seq_num = cmd->seq_num;
}

static int iwm_send_udma_wifi_cmd(struct iwm_priv *iwm,
                                  struct iwm_wifi_cmd *cmd)
{
        struct iwm_umac_wifi_out_hdr *umac_hdr;
        struct iwm_wifi_cmd_buff *buf;
        struct iwm_udma_wifi_cmd *udma_cmd = &cmd->udma_cmd;
        struct iwm_umac_cmd *umac_cmd = &cmd->umac_cmd;
        int ret;

        buf = &cmd->buf;

        buf->start -= sizeof(struct iwm_umac_wifi_out_hdr);
        buf->len += sizeof(struct iwm_umac_wifi_out_hdr);

        umac_hdr = (struct iwm_umac_wifi_out_hdr *)(buf->start);

        iwm_build_udma_wifi_hdr(iwm, &umac_hdr->hw_hdr, udma_cmd);
        iwm_build_umac_hdr(iwm, &umac_hdr->sw_hdr, umac_cmd);

        IWM_DBG_CMD(iwm, DBG,
                    "Send UDMA wifi cmd: opcode = 0x%x, UMAC opcode = 0x%x, "
                    "eop = 0x%x, count = 0x%x, credit_group = 0x%x, "
                    "ra_tid = 0x%x, lmac_offset = 0x%x, seqnum = %d\n",
                    UMAC_HDI_OUT_OPCODE_WIFI, umac_cmd->id,
                    udma_cmd->eop, udma_cmd->count, udma_cmd->credit_group,
                    udma_cmd->ra_tid, udma_cmd->lmac_offset, cmd->seq_num);

        if (umac_cmd->id == UMAC_CMD_OPCODE_WIFI_PASS_THROUGH)
                IWM_DBG_CMD(iwm, DBG, "\tLMAC opcode: 0x%x\n",
                            cmd->lmac_cmd.id);

        ret = iwm_tx_credit_alloc(iwm, udma_cmd->credit_group, buf->len);

        /* We keep sending UMAC reset regardless of the command credits.
         * The UMAC is supposed to be reset anyway and the Tx credits are
         * reinitialized afterwards. If we are lucky, the reset could
         * still be done even though we have run out of credits for the
         * command pool at this moment.*/
        if (ret && (umac_cmd->id != UMAC_CMD_OPCODE_RESET)) {
                IWM_DBG_TX(iwm, DBG, "Failed to alloc tx credit for cmd %d\n",
                           umac_cmd->id);
                return ret;
        }

        trace_iwm_tx_wifi_cmd(iwm, umac_hdr);
        return iwm_bus_send_chunk(iwm, buf->start, buf->len);
}

/* target_cmd a.k.a udma_nonwifi_cmd can be sent when UMAC is not available */
int iwm_hal_send_target_cmd(struct iwm_priv *iwm,
                            struct iwm_udma_nonwifi_cmd *udma_cmd,
                            const void *payload)
{
        struct iwm_nonwifi_cmd *cmd;
        int ret, seq_num;

        cmd = kzalloc(sizeof(struct iwm_nonwifi_cmd), GFP_KERNEL);
        if (!cmd) {
                IWM_ERR(iwm, "Couldn't alloc memory for hal cmd\n");
                return -ENOMEM;
        }

        seq_num = iwm_nonwifi_cmd_init(iwm, cmd, udma_cmd);

        if (cmd->udma_cmd.opcode == UMAC_HDI_OUT_OPCODE_WRITE ||
            cmd->udma_cmd.opcode == UMAC_HDI_OUT_OPCODE_WRITE_PERSISTENT) {
                cmd->buf.len = le32_to_cpu(cmd->udma_cmd.op1_sz);
                memcpy(&cmd->buf.payload, payload, cmd->buf.len);
        }

        ret = iwm_send_udma_nonwifi_cmd(iwm, cmd);

        if (!udma_cmd->resp)
                kfree(cmd);

        if (ret < 0)
                return ret;

        return seq_num;
}

static void iwm_build_lmac_hdr(struct iwm_priv *iwm, struct iwm_lmac_hdr *hdr,
                               struct iwm_lmac_cmd *cmd)
{
        memset(hdr, 0, sizeof(*hdr));

        hdr->id = cmd->id;
        hdr->flags = 0; /* Is this ever used? */
        hdr->seq_num = cmd->seq_num;
}

/*
 * iwm_hal_send_host_cmd(): sends commands to the UMAC or the LMAC.
 * Sending command to the LMAC is equivalent to sending a
 * regular UMAC command with the LMAC passthrough or the LMAC
 * wrapper UMAC command IDs.
 */
int iwm_hal_send_host_cmd(struct iwm_priv *iwm,
                          struct iwm_udma_wifi_cmd *udma_cmd,
                          struct iwm_umac_cmd *umac_cmd,
                          struct iwm_lmac_cmd *lmac_cmd,
                          const void *payload, u16 payload_size)
{
        struct iwm_wifi_cmd *cmd;
        struct iwm_lmac_hdr *hdr;
        int lmac_hdr_len = 0;
        int ret;

        cmd = kzalloc(sizeof(struct iwm_wifi_cmd), GFP_KERNEL);
        if (!cmd) {
                IWM_ERR(iwm, "Couldn't alloc memory for wifi hal cmd\n");
                return -ENOMEM;
        }

        iwm_wifi_cmd_init(iwm, cmd, udma_cmd, umac_cmd, lmac_cmd, payload_size);

        if (lmac_cmd) {
                hdr = (struct iwm_lmac_hdr *)(cmd->buf.start);

                iwm_build_lmac_hdr(iwm, hdr, &cmd->lmac_cmd);
                lmac_hdr_len = sizeof(struct iwm_lmac_hdr);
        }

        memcpy(cmd->buf.payload, payload, payload_size);
        cmd->buf.len = le16_to_cpu(umac_cmd->count);

        ret = iwm_send_udma_wifi_cmd(iwm, cmd);

        /* We free the cmd if we're not expecting any response */
        if (!umac_cmd->resp)
                kfree(cmd);
        return ret;
}

/*
 * iwm_hal_send_umac_cmd(): This is a special case for
 * iwm_hal_send_host_cmd() to send direct UMAC cmd (without
 * LMAC involved).
 */
int iwm_hal_send_umac_cmd(struct iwm_priv *iwm,
                          struct iwm_udma_wifi_cmd *udma_cmd,
                          struct iwm_umac_cmd *umac_cmd,
                          const void *payload, u16 payload_size)
{
        return iwm_hal_send_host_cmd(iwm, udma_cmd, umac_cmd, NULL,
                                     payload, payload_size);
}