drivers/net/ethernet/ti/netcp_sgmii.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SGMI module initialisation
   4  *
   5  * Copyright (C) 2014 Texas Instruments Incorporated
   6  * Authors:     Sandeep Nair <sandeep_n@ti.com>
   7  *              Sandeep Paulraj <s-paulraj@ti.com>
   8  *              Wingman Kwok <w-kwok2@ti.com>
   9  *
  10  */
  11
  12 #include "netcp.h"
  13
  14 #define SGMII_SRESET_RESET              BIT(0)
  15 #define SGMII_SRESET_RTRESET            BIT(1)
  16
  17 #define SGMII_REG_STATUS_LOCK           BIT(4)
  18 #define SGMII_REG_STATUS_LINK           BIT(0)
  19 #define SGMII_REG_STATUS_AUTONEG        BIT(2)
  20 #define SGMII_REG_CONTROL_AUTONEG       BIT(0)
  21
  22 #define SGMII23_OFFSET(x)       ((x - 2) * 0x100)
  23 #define SGMII_OFFSET(x)         ((x <= 1) ? (x * 0x100) : (SGMII23_OFFSET(x)))
  24
  25 /* SGMII registers */
  26 #define SGMII_SRESET_REG(x)   (SGMII_OFFSET(x) + 0x004)
  27 #define SGMII_CTL_REG(x)      (SGMII_OFFSET(x) + 0x010)
  28 #define SGMII_STATUS_REG(x)   (SGMII_OFFSET(x) + 0x014)
  29 #define SGMII_MRADV_REG(x)    (SGMII_OFFSET(x) + 0x018)
  30
  31 static void sgmii_write_reg(void __iomem *base, int reg, u32 val)
  32 {
  33         writel(val, base + reg);
  34 }
  35
  36 static u32 sgmii_read_reg(void __iomem *base, int reg)
  37 {
  38         return readl(base + reg);
  39 }
  40
  41 static void sgmii_write_reg_bit(void __iomem *base, int reg, u32 val)
  42 {
  43         writel((readl(base + reg) | val), base + reg);
  44 }
  45
  46 /* port is 0 based */
  47 int netcp_sgmii_reset(void __iomem *sgmii_ofs, int port)
  48 {
  49         /* Soft reset */
  50         sgmii_write_reg_bit(sgmii_ofs, SGMII_SRESET_REG(port),
  51                             SGMII_SRESET_RESET);
  52
  53         while ((sgmii_read_reg(sgmii_ofs, SGMII_SRESET_REG(port)) &
  54                 SGMII_SRESET_RESET) != 0x0)
  55                 ;
  56
  57         return 0;
  58 }
  59
  60 /* port is 0 based */
  61 bool netcp_sgmii_rtreset(void __iomem *sgmii_ofs, int port, bool set)
  62 {
  63         u32 reg;
  64         bool oldval;
  65
  66         /* Initiate a soft reset */
  67         reg = sgmii_read_reg(sgmii_ofs, SGMII_SRESET_REG(port));
  68         oldval = (reg & SGMII_SRESET_RTRESET) != 0x0;
  69         if (set)
  70                 reg |= SGMII_SRESET_RTRESET;
  71         else
  72                 reg &= ~SGMII_SRESET_RTRESET;
  73         sgmii_write_reg(sgmii_ofs, SGMII_SRESET_REG(port), reg);
  74         wmb();
  75
  76         return oldval;
  77 }
  78
  79 int netcp_sgmii_get_port_link(void __iomem *sgmii_ofs, int port)
  80 {
  81         u32 status = 0, link = 0;
  82
  83         status = sgmii_read_reg(sgmii_ofs, SGMII_STATUS_REG(port));
  84         if ((status & SGMII_REG_STATUS_LINK) != 0)
  85                 link = 1;
  86         return link;
  87 }
  88
  89 int netcp_sgmii_config(void __iomem *sgmii_ofs, int port, u32 interface)
  90 {
  91         unsigned int i, status, mask;
  92         u32 mr_adv_ability;
  93         u32 control;
  94
  95         switch (interface) {
  96         case SGMII_LINK_MAC_MAC_AUTONEG:
  97                 mr_adv_ability  = 0x9801;
  98                 control         = 0x21;
  99                 break;
 100
 101         case SGMII_LINK_MAC_PHY:
 102         case SGMII_LINK_MAC_PHY_NO_MDIO:
 103                 mr_adv_ability  = 1;
 104                 control         = 1;
 105                 break;
 106
 107         case SGMII_LINK_MAC_MAC_FORCED:
 108                 mr_adv_ability  = 0x9801;
 109                 control         = 0x20;
 110                 break;
 111
 112         case SGMII_LINK_MAC_FIBER:
 113                 mr_adv_ability  = 0x20;
 114                 control         = 0x1;
 115                 break;
 116
 117         default:
 118                 WARN_ONCE(1, "Invalid sgmii interface: %d\n", interface);
 119                 return -EINVAL;
 120         }
 121
 122         sgmii_write_reg(sgmii_ofs, SGMII_CTL_REG(port), 0);
 123
 124         /* Wait for the SerDes pll to lock */
 125         for (i = 0; i < 1000; i++)  {
 126                 usleep_range(1000, 2000);
 127                 status = sgmii_read_reg(sgmii_ofs, SGMII_STATUS_REG(port));
 128                 if ((status & SGMII_REG_STATUS_LOCK) != 0)
 129                         break;
 130         }
 131
 132         if ((status & SGMII_REG_STATUS_LOCK) == 0)
 133                 pr_err("serdes PLL not locked\n");
 134
 135         sgmii_write_reg(sgmii_ofs, SGMII_MRADV_REG(port), mr_adv_ability);
 136         sgmii_write_reg(sgmii_ofs, SGMII_CTL_REG(port), control);
 137
 138         mask = SGMII_REG_STATUS_LINK;
 139         if (control & SGMII_REG_CONTROL_AUTONEG)
 140                 mask |= SGMII_REG_STATUS_AUTONEG;
 141
 142         for (i = 0; i < 1000; i++)  {
 143                 usleep_range(200, 500);
 144                 status = sgmii_read_reg(sgmii_ofs, SGMII_STATUS_REG(port));
 145                 if ((status & mask) == mask)
 146                         break;
 147         }
 148
 149         return 0;
 150 }