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