drivers/usb/musb/am35x.c

   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@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 }