arch/arm/mach-socfpga/scan_manager.c

   1 /*
   2  *  Copyright (C) 2013 Altera Corporation <www.altera.com>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <errno.h>
   9 #include <asm/io.h>
  10 #include <asm/arch/freeze_controller.h>
  11 #include <asm/arch/scan_manager.h>
  12
  13 /*
  14  * Maximum polling loop to wait for IO scan chain engine becomes idle
  15  * to prevent infinite loop. It is important that this is NOT changed
  16  * to delay using timer functions, since at the time this function is
  17  * called, timer might not yet be inited.
  18  */
  19 #define SCANMGR_MAX_DELAY               100
  20
  21 /*
  22  * Maximum length of TDI_TDO packet payload is 128 bits,
  23  * represented by (length - 1) in TDI_TDO header.
  24  */
  25 #define TDI_TDO_MAX_PAYLOAD             127
  26
  27 #define SCANMGR_STAT_ACTIVE             (1 << 31)
  28 #define SCANMGR_STAT_WFIFOCNT_MASK      0x70000000
  29
  30 DECLARE_GLOBAL_DATA_PTR;
  31
  32 static const struct socfpga_scan_manager *scan_manager_base =
  33                 (void *)(SOCFPGA_SCANMGR_ADDRESS);
  34 static const struct socfpga_freeze_controller *freeze_controller_base =
  35                 (void *)(SOCFPGA_SYSMGR_ADDRESS + SYSMGR_FRZCTRL_ADDRESS);
  36
  37 /**
  38  * scan_chain_engine_is_idle() - Check if the JTAG scan chain is idle
  39  * @max_iter:   Maximum number of iterations to wait for idle
  40  *
  41  * Function to check IO scan chain engine status and wait if the engine is
  42  * is active. Poll the IO scan chain engine till maximum iteration reached.
  43  */
  44 static u32 scan_chain_engine_is_idle(u32 max_iter)
  45 {
  46         const u32 mask = SCANMGR_STAT_ACTIVE | SCANMGR_STAT_WFIFOCNT_MASK;
  47         u32 status;
  48
  49         /* Poll the engine until the scan engine is inactive. */
  50         do {
  51                 status = readl(&scan_manager_base->stat);
  52                 if (!(status & mask))
  53                         return 0;
  54         } while (max_iter--);
  55
  56         return -ETIMEDOUT;
  57 }
  58
  59 #define JTAG_BP_INSN            (1 << 0)
  60 #define JTAG_BP_TMS             (1 << 1)
  61 #define JTAG_BP_PAYLOAD         (1 << 2)
  62 #define JTAG_BP_2BYTE           (1 << 3)
  63 #define JTAG_BP_4BYTE           (1 << 4)
  64
  65 /**
  66  * scan_mgr_jtag_io() - Access the JTAG chain
  67  * @flags:      Control flags, used to configure the action on the JTAG
  68  * @iarg:       Instruction argument
  69  * @parg:       Payload argument or data
  70  *
  71  * Perform I/O on the JTAG chain
  72  */
  73 static void scan_mgr_jtag_io(const u32 flags, const u8 iarg, const u32 parg)
  74 {
  75         u32 data = parg;
  76
  77         if (flags & JTAG_BP_INSN) {     /* JTAG instruction */
  78                 /*
  79                  * The SCC JTAG register is LSB first, so make
  80                  * space for the instruction at the LSB.
  81                  */
  82                 data <<= 8;
  83                 if (flags & JTAG_BP_TMS) {
  84                         data |= (0 << 7);       /* TMS instruction. */
  85                         data |= iarg & 0x3f;    /* TMS arg is 6 bits. */
  86                         if (flags & JTAG_BP_PAYLOAD)
  87                                 data |= (1 << 6);
  88                 } else {
  89                         data |= (1 << 7);       /* TDI/TDO instruction. */
  90                         data |= iarg & 0xf;     /* TDI/TDO arg is 4 bits. */
  91                         if (flags & JTAG_BP_PAYLOAD)
  92                                 data |= (1 << 4);
  93                 }
  94         }
  95
  96         if (flags & JTAG_BP_4BYTE)
  97                 writel(data, &scan_manager_base->fifo_quad_byte);
  98         else if (flags & JTAG_BP_2BYTE)
  99                 writel(data & 0xffff, &scan_manager_base->fifo_double_byte);
 100         else
 101                 writel(data & 0xff, &scan_manager_base->fifo_single_byte);
 102 }
 103
 104 /**
 105  * scan_mgr_io_scan_chain_prg() - Program HPS IO Scan Chain
 106  * @io_scan_chain_id:           IO scan chain ID
 107  */
 108 static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id)
 109 {
 110         u32 residual;
 111         u32 io_scan_chain_len_in_bits;
 112         const unsigned long *iocsr_scan_chain;
 113         int i, ret, index = 0;
 114
 115         ret = iocsr_get_config_table(io_scan_chain_id, &iocsr_scan_chain,
 116                                      &io_scan_chain_len_in_bits);
 117         if (ret)
 118                 return 1;
 119
 120         /*
 121          * De-assert reinit if the IO scan chain is intended for HIO. In
 122          * this, its the chain 3.
 123          */
 124         if (io_scan_chain_id == 3)
 125                 clrbits_le32(&freeze_controller_base->hioctrl,
 126                              SYSMGR_FRZCTRL_HIOCTRL_DLLRST_MASK);
 127
 128         /*
 129          * Check if the scan chain engine is inactive and the
 130          * WFIFO is empty before enabling the IO scan chain
 131          */
 132         ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY);
 133         if (ret)
 134                 return ret;
 135
 136         /*
 137          * Enable IO Scan chain based on scan chain id
 138          * Note: only one chain can be enabled at a time
 139          */
 140         setbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
 141
 142         /* Program IO scan chain in 128-bit iteration */
 143         for (i = 0; i < io_scan_chain_len_in_bits / 128; i++) {
 144                 /* Write TDI_TDO packet header for 128-bit IO scan chain */
 145                 scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_2BYTE, 0x0,
 146                                  TDI_TDO_MAX_PAYLOAD);
 147
 148                 /* write 4 successive 32-bit IO scan chain data into WFIFO */
 149                 scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
 150                 scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
 151                 scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
 152                 scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
 153
 154                 /*
 155                  * Check if the scan chain engine has completed the
 156                  * IO scan chain data shifting
 157                  */
 158                 ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY);
 159                 if (ret)
 160                         goto error;
 161         }
 162
 163         residual = io_scan_chain_len_in_bits % 128;
 164
 165         /* Final TDI_TDO packet (if chain length is not aligned to 128 bits) */
 166         if (residual) {
 167                 /*
 168                  * Program the last part of IO scan chain write TDI_TDO
 169                  * packet header (2 bytes) to scan manager.
 170                  */
 171                 scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_2BYTE, 0x0,
 172                                  residual - 1);
 173
 174                 for (i = 0; i < residual / 32; i++) {
 175                         /*
 176                          * write remaining scan chain data into scan
 177                          * manager WFIFO with 4 bytes write
 178                          */
 179                         scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0,
 180                                          iocsr_scan_chain[index++]);
 181                 }
 182
 183                 residual = io_scan_chain_len_in_bits % 32;
 184                 if (residual > 24) {
 185                         /*
 186                          * write the last 4B scan chain data
 187                          * into scan manager WFIFO
 188                          */
 189                         scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0,
 190                                          iocsr_scan_chain[index]);
 191                 } else {
 192                         /*
 193                          * write the remaining 1 - 3 bytes scan chain
 194                          * data into scan manager WFIFO byte by byte
 195                          * to prevent JTAG engine shifting unused data
 196                          * from the FIFO and mistaken the data as a
 197                          * valid command (even though unused bits are
 198                          * set to 0, but just to prevent hardware
 199                          * glitch)
 200                          */
 201                         for (i = 0; i < residual; i += 8) {
 202                                 scan_mgr_jtag_io(0, 0x0,
 203                                          iocsr_scan_chain[index] >> i);
 204                         }
 205                 }
 206
 207                 /*
 208                  * Check if the scan chain engine has completed the
 209                  * IO scan chain data shifting
 210                  */
 211                 ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY);
 212                 if (ret)
 213                         goto error;
 214         }
 215
 216         /* Disable IO Scan chain when configuration done*/
 217         clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
 218         return 0;
 219
 220 error:
 221         /* Disable IO Scan chain when error detected */
 222         clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id);
 223         return ret;
 224 }
 225
 226 int scan_mgr_configure_iocsr(void)
 227 {
 228         int status = 0;
 229
 230         /* configure the IOCSR through scan chain */
 231         status |= scan_mgr_io_scan_chain_prg(0);
 232         status |= scan_mgr_io_scan_chain_prg(1);
 233         status |= scan_mgr_io_scan_chain_prg(2);
 234         status |= scan_mgr_io_scan_chain_prg(3);
 235         return status;
 236 }