text: /**
   * Copyright (c) 2014 Redpine Signals Inc.
   *
   * Permission to use, copy, modify, and/or 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.
   *
   */
  
  #include <linux/firmware.h>
  #include <net/rsi_91x.h>
  #include "rsi_sdio.h"
  #include "rsi_common.h"
  
  /**
   * rsi_sdio_master_access_msword() - This function sets the AHB master access
   *				     MS word in the SDIO slave registers.
   * @adapter: Pointer to the adapter structure.
   * @ms_word: ms word need to be initialized.
   *
   * Return: status: 0 on success, -1 on failure.
   */
  int rsi_sdio_master_access_msword(struct rsi_hw *adapter, u16 ms_word)
  {
  	u8 byte;
  	u8 function = 0;
  	int status = 0;
  
  	byte = (u8)(ms_word & 0x00FF);
  
  	rsi_dbg(INIT_ZONE,
  		"%s: MASTER_ACCESS_MSBYTE:0x%x\n", __func__, byte);
  
  	status = rsi_sdio_write_register(adapter,
  					 function,
  					 SDIO_MASTER_ACCESS_MSBYTE,
  					 &byte);
  	if (status) {
  		rsi_dbg(ERR_ZONE,
  			"%s: fail to access MASTER_ACCESS_MSBYTE\n",
  			__func__);
  		return -1;
  	}
  
  	byte = (u8)(ms_word >> 8);
  
  	rsi_dbg(INIT_ZONE, "%s:MASTER_ACCESS_LSBYTE:0x%x\n", __func__, byte);
  	status = rsi_sdio_write_register(adapter,
  					 function,
  					 SDIO_MASTER_ACCESS_LSBYTE,
  					 &byte);
  	return status;
  }
  
  void rsi_sdio_rx_thread(struct rsi_common *common)
  {
  	struct rsi_hw *adapter = common->priv;
  	struct rsi_91x_sdiodev *sdev = adapter->rsi_dev;
  	struct sk_buff *skb;
  	int status;
  
  	do {
  		rsi_wait_event(&sdev->rx_thread.event, EVENT_WAIT_FOREVER);
  		rsi_reset_event(&sdev->rx_thread.event);
  
  		while (true) {
  			if (atomic_read(&sdev->rx_thread.thread_done))
  				goto out;
  
  			skb = skb_dequeue(&sdev->rx_q.head);
  			if (!skb)
  				break;
  			if (sdev->rx_q.num_rx_pkts > 0)
  				sdev->rx_q.num_rx_pkts--;
  			status = rsi_read_pkt(common, skb->data, skb->len);
  			if (status) {
  				rsi_dbg(ERR_ZONE, "Failed to read the packet\n");
  				dev_kfree_skb(skb);
  				break;
  			}
  			dev_kfree_skb(skb);
  		}
  	} while (1);
  
  out:
  	rsi_dbg(INFO_ZONE, "%s: Terminated SDIO RX thread\n", __func__);
  	skb_queue_purge(&sdev->rx_q.head);
  	atomic_inc(&sdev->rx_thread.thread_done);
  	complete_and_exit(&sdev->rx_thread.completion, 0);
  }
  
  /**
   * rsi_process_pkt() - This Function reads rx_blocks register and figures out
   *		       the size of the rx pkt.
   * @common: Pointer to the driver private structure.
   *
   * Return: 0 on success, -1 on failure.
   */
  static int rsi_process_pkt(struct rsi_common *common)
  {
  	struct rsi_hw *adapter = common->priv;
  	struct rsi_91x_sdiodev *dev =
  		(struct rsi_91x_sdiodev *)adapter->rsi_dev;
  	u8 num_blks = 0;
  	u32 rcv_pkt_len = 0;
  	int status = 0;
  	u8 value = 0;
  	struct sk_buff *skb;
  
  	if (dev->rx_q.num_rx_pkts >= RSI_MAX_RX_PKTS)
  		return 0;
  
  	num_blks = ((adapter->interrupt_status & 1) |
  			((adapter->interrupt_status >> RECV_NUM_BLOCKS) << 1));
  
  	if (!num_blks) {
  		status = rsi_sdio_read_register(adapter,
  						SDIO_RX_NUM_BLOCKS_REG,
  						&value);
  		if (status) {
  			rsi_dbg(ERR_ZONE,
  				"%s: Failed to read pkt length from the card:\n",
  				__func__);
  			return status;
  		}
  		num_blks = value & 0x1f;
  	}
  
  	if (dev->write_fail == 2)
  		rsi_sdio_ack_intr(common->priv, (1 << MSDU_PKT_PENDING));
  
  	if (unlikely(!num_blks)) {
  		dev->write_fail = 2;
  		return -1;
  	}
  
  	rcv_pkt_len = (num_blks * 256);
  
  	skb = dev_alloc_skb(rcv_pkt_len);
  	if (!skb)
  		return -ENOMEM;
  
  	status = rsi_sdio_host_intf_read_pkt(adapter, skb->data, rcv_pkt_len);
  	if (status) {
  		rsi_dbg(ERR_ZONE, "%s: Failed to read packet from card\n",
  			__func__);
  		dev_kfree_skb(skb);
  		return status;
  	}
  	skb_put(skb, rcv_pkt_len);
  	skb_queue_tail(&dev->rx_q.head, skb);
  	dev->rx_q.num_rx_pkts++;
  
  	rsi_set_event(&dev->rx_thread.event);
  
  	return 0;
  }
  
  /**
   * rsi_init_sdio_slave_regs() - This function does the actual initialization
   *				of SDBUS slave registers.
   * @adapter: Pointer to the adapter structure.
   *
   * Return: status: 0 on success, -1 on failure.
   */
  int rsi_init_sdio_slave_regs(struct rsi_hw *adapter)
  {
  	struct rsi_91x_sdiodev *dev =
  		(struct rsi_91x_sdiodev *)adapter->rsi_dev;
  	u8 function = 0;
  	u8 byte;
  	int status = 0;
  
  	if (dev->next_read_delay) {
  		byte = dev->next_read_delay;
  		status = rsi_sdio_write_register(adapter,
  						 function,
  						 SDIO_NXT_RD_DELAY2,
  						 &byte);
  		if (status) {
  			rsi_dbg(ERR_ZONE,
  				"%s: Failed to write SDIO_NXT_RD_DELAY2\n",
  				__func__);
  			return -1;
  		}
  	}
  
  	if (dev->sdio_high_speed_enable) {
  		rsi_dbg(INIT_ZONE, "%s: Enabling SDIO High speed\n", __func__);
  		byte = 0x3;
  
  		status = rsi_sdio_write_register(adapter,
  						 function,
  						 SDIO_REG_HIGH_SPEED,
  						 &byte);
  		if (status) {
  			rsi_dbg(ERR_ZONE,
  				"%s: Failed to enable SDIO high speed\n",
  				__func__);
  			return -1;
  		}
  	}
  
  	/* This tells SDIO FIFO when to start read to host */
  	rsi_dbg(INIT_ZONE, "%s: Initializing SDIO read start level\n", __func__);
  	byte = 0x24;
  
  	status = rsi_sdio_write_register(adapter,
  					 function,
  					 SDIO_READ_START_LVL,
  					 &byte);
  	if (status) {
  		rsi_dbg(ERR_ZONE,
  			"%s: Failed to write SDIO_READ_START_LVL\n", __func__);
  		return -1;
  	}
  
  	rsi_dbg(INIT_ZONE, "%s: Initializing FIFO ctrl registers\n", __func__);
  	byte = (128 - 32);
  
  	status = rsi_sdio_write_register(adapter,
  					 function,
  					 SDIO_READ_FIFO_CTL,
  					 &byte);
  	if (status) {
  		rsi_dbg(ERR_ZONE,
  			"%s: Failed to write SDIO_READ_FIFO_CTL\n", __func__);
  		return -1;
  	}
  
  	byte = 32;
  	status = rsi_sdio_write_register(adapter,
  					 function,
  					 SDIO_WRITE_FIFO_CTL,
  					 &byte);
  	if (status) {
  		rsi_dbg(ERR_ZONE,
  			"%s: Failed to write SDIO_WRITE_FIFO_CTL\n", __func__);
  		return -1;
  	}
  
  	return 0;
  }
  
  /**
   * rsi_interrupt_handler() - This function read and process SDIO interrupts.
   * @adapter: Pointer to the adapter structure.
   *
   * Return: None.
   */
  void rsi_interrupt_handler(struct rsi_hw *adapter)
  {
  	struct rsi_common *common = adapter->priv;
  	struct rsi_91x_sdiodev *dev =
  		(struct rsi_91x_sdiodev *)adapter->rsi_dev;
  	int status;
  	enum sdio_interrupt_type isr_type;
  	u8 isr_status = 0;
  	u8 fw_status = 0;
  
  	dev->rx_info.sdio_int_counter++;
  
  	do {
  		mutex_lock(&common->rx_lock);
  		status = rsi_sdio_read_register(common->priv,
  						RSI_FN1_INT_REGISTER,
  						&isr_status);
  		if (status) {
  			rsi_dbg(ERR_ZONE,
  				"%s: Failed to Read Intr Status Register\n",
  				__func__);
  			mutex_unlock(&common->rx_lock);
  			return;
  		}
  		adapter->interrupt_status = isr_status;
  
  		if (isr_status == 0) {
  			rsi_set_event(&common->tx_thread.event);
  			dev->rx_info.sdio_intr_status_zero++;
  			mutex_unlock(&common->rx_lock);
  			return;
  		}
  
  		rsi_dbg(ISR_ZONE, "%s: Intr_status = %x %d %d\n",
  			__func__, isr_status, (1 << MSDU_PKT_PENDING),
  			(1 << FW_ASSERT_IND));
  
  		do {
  			RSI_GET_SDIO_INTERRUPT_TYPE(isr_status, isr_type);
  
  			switch (isr_type) {
  			case BUFFER_AVAILABLE:
  				status = rsi_sdio_check_buffer_status(adapter,
  								      0);
  				if (status < 0)
  					rsi_dbg(ERR_ZONE,
  						"%s: Failed to check buffer status\n",
  						__func__);
  				rsi_sdio_ack_intr(common->priv,
  						  (1 << PKT_BUFF_AVAILABLE));
  				rsi_set_event(&common->tx_thread.event);
  
  				rsi_dbg(ISR_ZONE,
  					"%s: ==> BUFFER_AVAILABLE <==\n",
  					__func__);
  				dev->buff_status_updated = true;
  				break;
  
  			case FIRMWARE_ASSERT_IND:
  				rsi_dbg(ERR_ZONE,
  					"%s: ==> FIRMWARE Assert <==\n",
  					__func__);
  				status = rsi_sdio_read_register(common->priv,
  							SDIO_FW_STATUS_REG,
  							&fw_status);
  				if (status) {
  					rsi_dbg(ERR_ZONE,
  						"%s: Failed to read f/w reg\n",
  						__func__);
  				} else {
  					rsi_dbg(ERR_ZONE,
  						"%s: Firmware Status is 0x%x\n",
  						__func__ , fw_status);
  					rsi_sdio_ack_intr(common->priv,
  							  (1 << FW_ASSERT_IND));
  				}
  
  				common->fsm_state = FSM_CARD_NOT_READY;
  				break;
  
  			case MSDU_PACKET_PENDING:
  				rsi_dbg(ISR_ZONE, "Pkt pending interrupt\n");
  				dev->rx_info.total_sdio_msdu_pending_intr++;
  
  				status = rsi_process_pkt(common);
  				if (status) {
  					rsi_dbg(ERR_ZONE,
  						"%s: Failed to read pkt\n",
  						__func__);
  					mutex_unlock(&common->rx_lock);
  					return;
  				}
  				break;
  			default:
  				rsi_sdio_ack_intr(common->priv, isr_status);
  				dev->rx_info.total_sdio_unknown_intr++;
  				isr_status = 0;
  				rsi_dbg(ISR_ZONE,
  					"Unknown Interrupt %x\n",
  					isr_status);
  				break;
  			}
  			isr_status ^= BIT(isr_type - 1);
  		} while (isr_status);
  		mutex_unlock(&common->rx_lock);
  	} while (1);
  }
  
  /* This function is used to read buffer status register and
   * set relevant fields in rsi_91x_sdiodev struct.
   */
  int rsi_sdio_check_buffer_status(struct rsi_hw *adapter, u8 q_num)
  {
  	struct rsi_common *common = adapter->priv;
  	struct rsi_91x_sdiodev *dev =
  		(struct rsi_91x_sdiodev *)adapter->rsi_dev;
  	u8 buf_status = 0;
  	int status = 0;
  	static int counter = 4;
  
  	if (!dev->buff_status_updated && counter) {
  		counter--;
  		goto out;
  	}
  
  	dev->buff_status_updated = false;
  	status = rsi_sdio_read_register(common->priv,
  					RSI_DEVICE_BUFFER_STATUS_REGISTER,
  					&buf_status);
  
  	if (status) {
  		rsi_dbg(ERR_ZONE,
  			"%s: Failed to read status register\n", __func__);
  		return -1;
  	}
  
  	if (buf_status & (BIT(PKT_MGMT_BUFF_FULL))) {
  		if (!dev->rx_info.mgmt_buffer_full)
  			dev->rx_info.mgmt_buf_full_counter++;
  		dev->rx_info.mgmt_buffer_full = true;
  	} else {
  		dev->rx_info.mgmt_buffer_full = false;
  	}
  
  	if (buf_status & (BIT(PKT_BUFF_FULL))) {
  		if (!dev->rx_info.buffer_full)
  			dev->rx_info.buf_full_counter++;
  		dev->rx_info.buffer_full = true;
  	} else {
  		dev->rx_info.buffer_full = false;
  	}
  
  	if (buf_status & (BIT(PKT_BUFF_SEMI_FULL))) {
  		if (!dev->rx_info.semi_buffer_full)
  			dev->rx_info.buf_semi_full_counter++;
  		dev->rx_info.semi_buffer_full = true;
  	} else {
  		dev->rx_info.semi_buffer_full = false;
  	}
  
  	if (dev->rx_info.mgmt_buffer_full || dev->rx_info.buf_full_counter)
  		counter = 1;
  	else
  		counter = 4;
  
  out:
  	if ((q_num == MGMT_SOFT_Q) && (dev->rx_info.mgmt_buffer_full))
  		return QUEUE_FULL;
  
  	if ((q_num < MGMT_SOFT_Q) && (dev->rx_info.buffer_full))
  		return QUEUE_FULL;
  
  	return QUEUE_NOT_FULL;
  }
  
  /**
   * rsi_sdio_determine_event_timeout() - This Function determines the event
   *					timeout duration.
   * @adapter: Pointer to the adapter structure.
   *
   * Return: timeout duration is returned.
   */
  int rsi_sdio_determine_event_timeout(struct rsi_hw *adapter)
  {
  	struct rsi_91x_sdiodev *dev =
  		(struct rsi_91x_sdiodev *)adapter->rsi_dev;
  
  	/* Once buffer full is seen, event timeout to occur every 2 msecs */
  	if (dev->rx_info.buffer_full)
  		return 2;
  
  	return EVENT_WAIT_FOREVER;
  }
  