text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * bdc_cmd.c - BRCM BDC USB3.0 device controller
   *
   * Copyright (C) 2014 Broadcom Corporation
   *
   * Author: Ashwini Pahuja
   */
  #include <linux/scatterlist.h>
  #include <linux/slab.h>
  
  #include "bdc.h"
  #include "bdc_cmd.h"
  #include "bdc_dbg.h"
  
  /* Issues a cmd to cmd processor and waits for cmd completion */
  static int bdc_issue_cmd(struct bdc *bdc, u32 cmd_sc, u32 param0,
  							u32 param1, u32 param2)
  {
  	u32 timeout = BDC_CMD_TIMEOUT;
  	u32 cmd_status;
  	u32 temp;
  
  	bdc_writel(bdc->regs, BDC_CMDPAR0, param0);
  	bdc_writel(bdc->regs, BDC_CMDPAR1, param1);
  	bdc_writel(bdc->regs, BDC_CMDPAR2, param2);
  
  	/* Issue the cmd */
  	/* Make sure the cmd params are written before asking HW to exec cmd */
  	wmb();
  	bdc_writel(bdc->regs, BDC_CMDSC, cmd_sc | BDC_CMD_CWS | BDC_CMD_SRD);
  	do {
  		temp = bdc_readl(bdc->regs, BDC_CMDSC);
  		dev_dbg_ratelimited(bdc->dev, "cmdsc=%x", temp);
  		cmd_status =  BDC_CMD_CST(temp);
  		if (cmd_status != BDC_CMDS_BUSY)  {
  			dev_dbg(bdc->dev,
  				"command completed cmd_sts:%x\n", cmd_status);
  			return cmd_status;
  		}
  		udelay(1);
  	} while (timeout--);
  
  	dev_err(bdc->dev,
  		"command operation timedout cmd_status=%d\n", cmd_status);
  
  	return cmd_status;
  }
  
  /* Submits cmd and analyze the return value of bdc_issue_cmd */
  static int bdc_submit_cmd(struct bdc *bdc, u32 cmd_sc,
  					u32 param0, u32 param1,	u32 param2)
  {
  	u32 temp, cmd_status;
  	int ret;
  
  	temp = bdc_readl(bdc->regs, BDC_CMDSC);
  	dev_dbg(bdc->dev,
  		"%s:CMDSC:%08x cmdsc:%08x param0=%08x param1=%08x param2=%08x\n",
  		 __func__, temp, cmd_sc, param0, param1, param2);
  
  	cmd_status = BDC_CMD_CST(temp);
  	if (cmd_status  ==  BDC_CMDS_BUSY) {
  		dev_err(bdc->dev, "command processor busy: %x\n", cmd_status);
  		return -EBUSY;
  	}
  	ret = bdc_issue_cmd(bdc, cmd_sc, param0, param1, param2);
  	switch (ret) {
  	case BDC_CMDS_SUCC:
  		dev_dbg(bdc->dev, "command completed successfully\n");
  		ret = 0;
  		break;
  
  	case BDC_CMDS_PARA:
  		dev_err(bdc->dev, "command parameter error\n");
  		ret = -EINVAL;
  		break;
  
  	case BDC_CMDS_STAT:
  		dev_err(bdc->dev, "Invalid device/ep state\n");
  		ret = -EINVAL;
  		break;
  
  	case BDC_CMDS_FAIL:
  		dev_err(bdc->dev, "Command failed?\n");
  		ret = -EAGAIN;
  		break;
  
  	case BDC_CMDS_INTL:
  		dev_err(bdc->dev, "BDC Internal error\n");
  		ret = -ECONNRESET;
  		break;
  
  	case BDC_CMDS_BUSY:
  		dev_err(bdc->dev,
  			"command timedout waited for %dusec\n",
  			BDC_CMD_TIMEOUT);
  		ret = -ECONNRESET;
  		break;
  	default:
  		dev_dbg(bdc->dev, "Unknown command completion code:%x\n", ret);
  	}
  
  	return ret;
  }
  
  /* Deconfigure the endpoint from HW */
  int bdc_dconfig_ep(struct bdc *bdc, struct bdc_ep *ep)
  {
  	u32 cmd_sc;
  
  	cmd_sc = BDC_SUB_CMD_DRP_EP|BDC_CMD_EPN(ep->ep_num)|BDC_CMD_EPC;
  	dev_dbg(bdc->dev, "%s ep->ep_num =%d cmd_sc=%x\n", __func__,
  							ep->ep_num, cmd_sc);
  
  	return bdc_submit_cmd(bdc, cmd_sc, 0, 0, 0);
  }
  
  /* Reinitalize the bdlist after config ep command */
  static void ep_bd_list_reinit(struct bdc_ep *ep)
  {
  	struct bdc *bdc = ep->bdc;
  	struct bdc_bd *bd;
  
  	ep->bd_list.eqp_bdi = 0;
  	ep->bd_list.hwd_bdi = 0;
  	bd = ep->bd_list.bd_table_array[0]->start_bd;
  	dev_dbg(bdc->dev, "%s ep:%p bd:%p\n", __func__, ep, bd);
  	memset(bd, 0, sizeof(struct bdc_bd));
  	bd->offset[3] |= cpu_to_le32(BD_SBF);
  }
  
  /* Configure an endpoint */
  int bdc_config_ep(struct bdc *bdc, struct bdc_ep *ep)
  {
  	const struct usb_ss_ep_comp_descriptor *comp_desc;
  	const struct usb_endpoint_descriptor	*desc;
  	u32 param0, param1, param2, cmd_sc;
  	u32 mps, mbs, mul, si;
  	int ret;
  
  	desc = ep->desc;
  	comp_desc = ep->comp_desc;
  	cmd_sc = mul = mbs = param2 = 0;
  	param0 = lower_32_bits(ep->bd_list.bd_table_array[0]->dma);
  	param1 = upper_32_bits(ep->bd_list.bd_table_array[0]->dma);
  	cpu_to_le32s(&param0);
  	cpu_to_le32s(&param1);
  
  	dev_dbg(bdc->dev, "%s: param0=%08x param1=%08x",
  						__func__, param0, param1);
  	si = desc->bInterval;
  	si = clamp_val(si, 1, 16) - 1;
  
  	mps = usb_endpoint_maxp(desc);
  	mps &= 0x7ff;
  	param2 |= mps << MP_SHIFT;
  	param2 |= usb_endpoint_type(desc) << EPT_SHIFT;
  
  	switch (bdc->gadget.speed) {
  	case USB_SPEED_SUPER:
  		if (usb_endpoint_xfer_int(desc) ||
  					usb_endpoint_xfer_isoc(desc)) {
  			param2 |= si;
  			if (usb_endpoint_xfer_isoc(desc) && comp_desc)
  					mul = comp_desc->bmAttributes;
  
  		}
  		param2 |= mul << EPM_SHIFT;
  		if (comp_desc)
  			mbs = comp_desc->bMaxBurst;
  		param2 |= mbs << MB_SHIFT;
  		break;
  
  	case USB_SPEED_HIGH:
  		if (usb_endpoint_xfer_isoc(desc) ||
  					usb_endpoint_xfer_int(desc)) {
  			param2 |= si;
  
  			mbs = usb_endpoint_maxp_mult(desc);
  			param2 |= mbs << MB_SHIFT;
  		}
  		break;
  
  	case USB_SPEED_FULL:
  	case USB_SPEED_LOW:
  		/* the hardware accepts SI in 125usec range */
  		if (usb_endpoint_xfer_isoc(desc))
  			si += 3;
  
  		/*
  		 * FS Int endpoints can have si of 1-255ms but the controller
  		 * accepts 2^bInterval*125usec, so convert ms to nearest power
  		 * of 2
  		 */
  		if (usb_endpoint_xfer_int(desc))
  			si = fls(desc->bInterval * 8) - 1;
  
  		param2 |= si;
  		break;
  	default:
  		dev_err(bdc->dev, "UNKNOWN speed ERR\n");
  		return -EINVAL;
  	}
  
  	cmd_sc |= BDC_CMD_EPC|BDC_CMD_EPN(ep->ep_num)|BDC_SUB_CMD_ADD_EP;
  
  	dev_dbg(bdc->dev, "cmd_sc=%x param2=%08x\n", cmd_sc, param2);
  	ret = bdc_submit_cmd(bdc, cmd_sc, param0, param1, param2);
  	if (ret) {
  		dev_err(bdc->dev, "command failed :%x\n", ret);
  		return ret;
  	}
  	ep_bd_list_reinit(ep);
  
  	return ret;
  }
  
  /*
   * Change the HW deq pointer, if this command is successful, HW will start
   * fetching the next bd from address dma_addr.
   */
  int bdc_ep_bla(struct bdc *bdc, struct bdc_ep *ep, dma_addr_t dma_addr)
  {
  	u32 param0, param1;
  	u32 cmd_sc = 0;
  
  	dev_dbg(bdc->dev, "%s: add=%08llx\n", __func__,
  				(unsigned long long)(dma_addr));
  	param0 = lower_32_bits(dma_addr);
  	param1 = upper_32_bits(dma_addr);
  	cpu_to_le32s(&param0);
  	cpu_to_le32s(&param1);
  
  	cmd_sc |= BDC_CMD_EPN(ep->ep_num)|BDC_CMD_BLA;
  	dev_dbg(bdc->dev, "cmd_sc=%x\n", cmd_sc);
  
  	return bdc_submit_cmd(bdc, cmd_sc, param0, param1, 0);
  }
  
  /* Set the address sent bu Host in SET_ADD request */
  int bdc_address_device(struct bdc *bdc, u32 add)
  {
  	u32 cmd_sc = 0;
  	u32 param2;
  
  	dev_dbg(bdc->dev, "%s: add=%d\n", __func__, add);
  	cmd_sc |=  BDC_SUB_CMD_ADD|BDC_CMD_DVC;
  	param2 = add & 0x7f;
  
  	return bdc_submit_cmd(bdc, cmd_sc, 0, 0, param2);
  }
  
  /* Send a Function Wake notification packet using FH command */
  int bdc_function_wake_fh(struct bdc *bdc, u8 intf)
  {
  	u32 param0, param1;
  	u32 cmd_sc = 0;
  
  	param0 = param1 = 0;
  	dev_dbg(bdc->dev, "%s intf=%d\n", __func__, intf);
  	cmd_sc  |=  BDC_CMD_FH;
  	param0 |= TRA_PACKET;
  	param0 |= (bdc->dev_addr << 25);
  	param1 |= DEV_NOTF_TYPE;
  	param1 |= (FWK_SUBTYPE<<4);
  	dev_dbg(bdc->dev, "param0=%08x param1=%08x\n", param0, param1);
  
  	return bdc_submit_cmd(bdc, cmd_sc, param0, param1, 0);
  }
  
  /* Send a Function Wake notification packet using DNC command */
  int bdc_function_wake(struct bdc *bdc, u8 intf)
  {
  	u32 cmd_sc = 0;
  	u32 param2 = 0;
  
  	dev_dbg(bdc->dev, "%s intf=%d", __func__, intf);
  	param2 |= intf;
  	cmd_sc |= BDC_SUB_CMD_FWK|BDC_CMD_DNC;
  
  	return bdc_submit_cmd(bdc, cmd_sc, 0, 0, param2);
  }
  
  /* Stall the endpoint */
  int bdc_ep_set_stall(struct bdc *bdc, int epnum)
  {
  	u32 cmd_sc = 0;
  
  	dev_dbg(bdc->dev, "%s epnum=%d\n", __func__, epnum);
  	/* issue a stall endpoint command */
  	cmd_sc |=  BDC_SUB_CMD_EP_STL | BDC_CMD_EPN(epnum) | BDC_CMD_EPO;
  
  	return bdc_submit_cmd(bdc, cmd_sc, 0, 0, 0);
  }
  
  /* resets the endpoint, called when host sends CLEAR_FEATURE(HALT) */
  int bdc_ep_clear_stall(struct bdc *bdc, int epnum)
  {
  	struct bdc_ep *ep;
  	u32 cmd_sc = 0;
  	int ret;
  
  	dev_dbg(bdc->dev, "%s: epnum=%d\n", __func__, epnum);
  	ep = bdc->bdc_ep_array[epnum];
  	/*
  	 * If we are not in stalled then stall Endpoint and issue clear stall,
  	 * his will reset the seq number for non EP0.
  	 */
  	if (epnum != 1) {
  		/* if the endpoint it not stallled */
  		if (!(ep->flags & BDC_EP_STALL)) {
  			ret = bdc_ep_set_stall(bdc, epnum);
  			if (ret)
  				return ret;
  		}
  	}
  	/* Preserve the seq number for ep0 only */
  	if (epnum != 1)
  		cmd_sc |= BDC_CMD_EPO_RST_SN;
  
  	/* issue a reset endpoint command */
  	cmd_sc |=  BDC_SUB_CMD_EP_RST | BDC_CMD_EPN(epnum) | BDC_CMD_EPO;
  
  	ret = bdc_submit_cmd(bdc, cmd_sc, 0, 0, 0);
  	if (ret) {
  		dev_err(bdc->dev, "command failed:%x\n", ret);
  		return ret;
  	}
  	bdc_notify_xfr(bdc, epnum);
  
  	return ret;
  }
  
  /* Stop the endpoint, called when software wants to dequeue some request */
  int bdc_stop_ep(struct bdc *bdc, int epnum)
  {
  	struct bdc_ep *ep;
  	u32 cmd_sc = 0;
  	int ret;
  
  	ep = bdc->bdc_ep_array[epnum];
  	dev_dbg(bdc->dev, "%s: ep:%s ep->flags:%08x\n", __func__,
  						ep->name, ep->flags);
  	/* Endpoint has to be in running state to execute stop ep command */
  	if (!(ep->flags & BDC_EP_ENABLED)) {
  		dev_err(bdc->dev, "stop endpoint called for disabled ep\n");
  		return   -EINVAL;
  	}
  	if ((ep->flags & BDC_EP_STALL) || (ep->flags & BDC_EP_STOP))
  		return 0;
  
  	/* issue a stop endpoint command */
  	cmd_sc |= BDC_CMD_EP0_XSD | BDC_SUB_CMD_EP_STP
  				| BDC_CMD_EPN(epnum) | BDC_CMD_EPO;
  
  	ret = bdc_submit_cmd(bdc, cmd_sc, 0, 0, 0);
  	if (ret) {
  		dev_err(bdc->dev,
  			"stop endpoint command didn't complete:%d ep:%s\n",
  			ret, ep->name);
  		return ret;
  	}
  	ep->flags |= BDC_EP_STOP;
  	bdc_dump_epsts(bdc);
  
  	return ret;
  }
  