text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * am35x.c - TI's AM35x platform specific usb wrapper functions.
   *
   * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
   *
   * Based on drivers/usb/musb/da8xx.c
   *
   * Copyright (c) 2010 Texas Instruments Incorporated
   */
  
  #include <common.h>
  
  #include "am35x.h"
  
  /* MUSB platform configuration */
  struct musb_config musb_cfg = {
  	.regs		= (struct musb_regs *)AM35X_USB_OTG_CORE_BASE,
  	.timeout	= AM35X_USB_OTG_TIMEOUT,
  	.musb_speed	= 0,
  };
  
  /*
   * Enable the USB phy
   */
  static u8 phy_on(void)
  {
  	u32 devconf2;
  	u32 timeout;
  
  	devconf2 = readl(&am35x_scm_general_regs->devconf2);
  
  	devconf2 &= ~(DEVCONF2_RESET | DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN |
  		      DEVCONF2_OTGMODE | DEVCONF2_REFFREQ |
  		      DEVCONF2_PHY_GPIOMODE);
  	devconf2 |= DEVCONF2_SESENDEN | DEVCONF2_VBDTCTEN | DEVCONF2_PHY_PLLON |
  		    DEVCONF2_REFFREQ_13MHZ | DEVCONF2_DATPOL;
  
  	writel(devconf2, &am35x_scm_general_regs->devconf2);
  
  	/* wait until the USB phy is turned on */
  	timeout = musb_cfg.timeout;
  	while (timeout--)
  		if (readl(&am35x_scm_general_regs->devconf2) & DEVCONF2_PHYCKGD)
  			return 1;
  
  	/* USB phy was not turned on */
  	return 0;
  }
  
  /*
   * Disable the USB phy
   */
  static void phy_off(void)
  {
  	u32 devconf2;
  
  	/*
  	 * Power down the on-chip PHY.
  	 */
  	devconf2 = readl(&am35x_scm_general_regs->devconf2);
  
  	devconf2 &= ~DEVCONF2_PHY_PLLON;
  	devconf2 |= DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN;
  	writel(devconf2, &am35x_scm_general_regs->devconf2);
  }
  
  /*
   * This function performs platform specific initialization for usb0.
   */
  int musb_platform_init(void)
  {
  	u32 revision;
  	u32 sw_reset;
  
  	/* global usb reset */
  	sw_reset = readl(&am35x_scm_general_regs->ip_sw_reset);
  	sw_reset |= (1 << 0);
  	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
  	sw_reset &= ~(1 << 0);
  	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
  
  	/* reset the controller */
  	writel(0x1, &am35x_usb_regs->control);
  	udelay(5000);
  
  	/* start the on-chip usb phy and its pll */
  	if (phy_on() == 0)
  		return -1;
  
  	/* Returns zero if e.g. not clocked */
  	revision = readl(&am35x_usb_regs->revision);
  	if (revision == 0)
  		return -1;
  
  	return 0;
  }
  
  /*
   * This function performs platform specific deinitialization for usb0.
   */
  void musb_platform_deinit(void)
  {
  	/* Turn off the phy */
  	phy_off();
  }
  
  /*
   * This function reads data from endpoint fifo for AM35x
   * which supports only 32bit read operation.
   *
   * ep           - endpoint number
   * length       - number of bytes to read from FIFO
   * fifo_data    - pointer to data buffer into which data is read
   */
  __attribute__((weak))
  void read_fifo(u8 ep, u32 length, void *fifo_data)
  {
  	u8  *data = (u8 *)fifo_data;
  	u32 val;
  	int i;
  
  	/* select the endpoint index */
  	writeb(ep, &musbr->index);
  
  	if (length > 4) {
  		for (i = 0; i < (length >> 2); i++) {
  			val = readl(&musbr->fifox[ep]);
  			memcpy(data, &val, 4);
  			data += 4;
  		}
  		length %= 4;
  	}
  	if (length > 0) {
  		val = readl(&musbr->fifox[ep]);
  		memcpy(data, &val, length);
  	}
  }
  