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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * am35x.c - TI's AM35x platform specific usb wrapper functions.
      4  *
      5  * Author: Ajay Kumar Gupta <ajay.gupta (at) ti.com>
      6  *
      7  * Based on drivers/usb/musb/da8xx.c
      8  *
      9  * Copyright (c) 2010 Texas Instruments Incorporated
     10  */
     11 
     12 #include <common.h>
     13 
     14 #include "am35x.h"
     15 
     16 /* MUSB platform configuration */
     17 struct musb_config musb_cfg = {
     18 	.regs		= (struct musb_regs *)AM35X_USB_OTG_CORE_BASE,
     19 	.timeout	= AM35X_USB_OTG_TIMEOUT,
     20 	.musb_speed	= 0,
     21 };
     22 
     23 /*
     24  * Enable the USB phy
     25  */
     26 static u8 phy_on(void)
     27 {
     28 	u32 devconf2;
     29 	u32 timeout;
     30 
     31 	devconf2 = readl(&am35x_scm_general_regs->devconf2);
     32 
     33 	devconf2 &= ~(DEVCONF2_RESET | DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN |
     34 		      DEVCONF2_OTGMODE | DEVCONF2_REFFREQ |
     35 		      DEVCONF2_PHY_GPIOMODE);
     36 	devconf2 |= DEVCONF2_SESENDEN | DEVCONF2_VBDTCTEN | DEVCONF2_PHY_PLLON |
     37 		    DEVCONF2_REFFREQ_13MHZ | DEVCONF2_DATPOL;
     38 
     39 	writel(devconf2, &am35x_scm_general_regs->devconf2);
     40 
     41 	/* wait until the USB phy is turned on */
     42 	timeout = musb_cfg.timeout;
     43 	while (timeout--)
     44 		if (readl(&am35x_scm_general_regs->devconf2) & DEVCONF2_PHYCKGD)
     45 			return 1;
     46 
     47 	/* USB phy was not turned on */
     48 	return 0;
     49 }
     50 
     51 /*
     52  * Disable the USB phy
     53  */
     54 static void phy_off(void)
     55 {
     56 	u32 devconf2;
     57 
     58 	/*
     59 	 * Power down the on-chip PHY.
     60 	 */
     61 	devconf2 = readl(&am35x_scm_general_regs->devconf2);
     62 
     63 	devconf2 &= ~DEVCONF2_PHY_PLLON;
     64 	devconf2 |= DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN;
     65 	writel(devconf2, &am35x_scm_general_regs->devconf2);
     66 }
     67 
     68 /*
     69  * This function performs platform specific initialization for usb0.
     70  */
     71 int musb_platform_init(void)
     72 {
     73 	u32 revision;
     74 	u32 sw_reset;
     75 
     76 	/* global usb reset */
     77 	sw_reset = readl(&am35x_scm_general_regs->ip_sw_reset);
     78 	sw_reset |= (1 << 0);
     79 	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
     80 	sw_reset &= ~(1 << 0);
     81 	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
     82 
     83 	/* reset the controller */
     84 	writel(0x1, &am35x_usb_regs->control);
     85 	udelay(5000);
     86 
     87 	/* start the on-chip usb phy and its pll */
     88 	if (phy_on() == 0)
     89 		return -1;
     90 
     91 	/* Returns zero if e.g. not clocked */
     92 	revision = readl(&am35x_usb_regs->revision);
     93 	if (revision == 0)
     94 		return -1;
     95 
     96 	return 0;
     97 }
     98 
     99 /*
    100  * This function performs platform specific deinitialization for usb0.
    101  */
    102 void musb_platform_deinit(void)
    103 {
    104 	/* Turn off the phy */
    105 	phy_off();
    106 }
    107 
    108 /*
    109  * This function reads data from endpoint fifo for AM35x
    110  * which supports only 32bit read operation.
    111  *
    112  * ep           - endpoint number
    113  * length       - number of bytes to read from FIFO
    114  * fifo_data    - pointer to data buffer into which data is read
    115  */
    116 __attribute__((weak))
    117 void read_fifo(u8 ep, u32 length, void *fifo_data)
    118 {
    119 	u8  *data = (u8 *)fifo_data;
    120 	u32 val;
    121 	int i;
    122 
    123 	/* select the endpoint index */
    124 	writeb(ep, &musbr->index);
    125 
    126 	if (length > 4) {
    127 		for (i = 0; i < (length >> 2); i++) {
    128 			val = readl(&musbr->fifox[ep]);
    129 			memcpy(data, &val, 4);
    130 			data += 4;
    131 		}
    132 		length %= 4;
    133 	}
    134 	if (length > 0) {
    135 		val = readl(&musbr->fifox[ep]);
    136 		memcpy(data, &val, length);
    137 	}
    138 }
    139