arm: socfpga: scan: Introduce generic JTAG accessor
Introduce generic function for accessing the JTAG scan chains in the
SCC manager. Make use of this function throughout the SCC manager to
replace the ad-hoc writes to registers and make the code less cryptic.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Dinh Nguyen <dinguyen@opensource.altera.com>
diff --git a/arch/arm/mach-socfpga/scan_manager.c b/arch/arm/mach-socfpga/scan_manager.c
index 3f244b9..a7434e4 100644
--- a/arch/arm/mach-socfpga/scan_manager.c
+++ b/arch/arm/mach-socfpga/scan_manager.c
@@ -50,13 +50,57 @@
return -ETIMEDOUT;
}
+#define JTAG_BP_INSN (1 << 0)
+#define JTAG_BP_TMS (1 << 1)
+#define JTAG_BP_PAYLOAD (1 << 2)
+#define JTAG_BP_2BYTE (1 << 3)
+#define JTAG_BP_4BYTE (1 << 4)
+
+/**
+ * scan_mgr_jtag_io() - Access the JTAG chain
+ * @flags: Control flags, used to configure the action on the JTAG
+ * @iarg: Instruction argument
+ * @parg: Payload argument or data
+ *
+ * Perform I/O on the JTAG chain
+ */
+static void scan_mgr_jtag_io(const u32 flags, const u8 iarg, const u32 parg)
+{
+ u32 data = parg;
+
+ if (flags & JTAG_BP_INSN) { /* JTAG instruction */
+ /*
+ * The SCC JTAG register is LSB first, so make
+ * space for the instruction at the LSB.
+ */
+ data <<= 8;
+ if (flags & JTAG_BP_TMS) {
+ data |= (0 << 7); /* TMS instruction. */
+ data |= iarg & 0x3f; /* TMS arg is 6 bits. */
+ if (flags & JTAG_BP_PAYLOAD)
+ data |= (1 << 6);
+ } else {
+ data |= (1 << 7); /* TDI/TDO instruction. */
+ data |= iarg & 0xf; /* TDI/TDO arg is 4 bits. */
+ if (flags & JTAG_BP_PAYLOAD)
+ data |= (1 << 4);
+ }
+ }
+
+ if (flags & JTAG_BP_4BYTE)
+ writel(data, &scan_manager_base->fifo_quad_byte);
+ else if (flags & JTAG_BP_2BYTE)
+ writel(data & 0xffff, &scan_manager_base->fifo_double_byte);
+ else
+ writel(data & 0xff, &scan_manager_base->fifo_single_byte);
+}
+
/**
* scan_mgr_io_scan_chain_prg() - Program HPS IO Scan Chain
* @io_scan_chain_id: IO scan chain ID
*/
static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id)
{
- uint16_t tdi_tdo_header;
uint32_t io_program_iter;
uint32_t io_scan_chain_data_residual;
uint32_t residual;
@@ -101,27 +145,17 @@
io_scan_chain_data_residual = io_scan_chain_len_in_bits &
IO_SCAN_CHAIN_128BIT_MASK;
- /* Construct TDI_TDO packet for 128-bit IO scan chain (2 bytes) */
- tdi_tdo_header = TDI_TDO_HEADER_FIRST_BYTE |
- (TDI_TDO_MAX_PAYLOAD << TDI_TDO_HEADER_SECOND_BYTE_SHIFT);
-
/* Program IO scan chain in 128-bit iteration */
for (i = 0; i < io_program_iter; i++) {
- /* write TDI_TDO packet header to scan manager */
- writel(tdi_tdo_header, &scan_manager_base->fifo_double_byte);
-
- /* calculate array index. Multiply by 4 as write 4 x 32bits */
- index = i * 4;
+ /* Write TDI_TDO packet header for 128-bit IO scan chain */
+ scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_2BYTE, 0x0,
+ TDI_TDO_MAX_PAYLOAD);
/* write 4 successive 32-bit IO scan chain data into WFIFO */
- writel(iocsr_scan_chain[index],
- &scan_manager_base->fifo_quad_byte);
- writel(iocsr_scan_chain[index + 1],
- &scan_manager_base->fifo_quad_byte);
- writel(iocsr_scan_chain[index + 2],
- &scan_manager_base->fifo_quad_byte);
- writel(iocsr_scan_chain[index + 3],
- &scan_manager_base->fifo_quad_byte);
+ scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
+ scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
+ scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
+ scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0, iocsr_scan_chain[index++]);
/*
* Check if the scan chain engine has completed the
@@ -132,9 +166,6 @@
goto error;
}
- /* Calculate array index for final TDI_TDO packet */
- index = io_program_iter * 4;
-
/* Final TDI_TDO packet if any */
if (io_scan_chain_data_residual) {
/*
@@ -145,29 +176,21 @@
IO_SCAN_CHAIN_32BIT_SHIFT;
/*
- * Construct TDI_TDO packet for remaining IO
- * scan chain (2 bytes)
+ * Program the last part of IO scan chain write TDI_TDO
+ * packet header (2 bytes) to scan manager.
*/
- tdi_tdo_header = TDI_TDO_HEADER_FIRST_BYTE |
- ((io_scan_chain_data_residual - 1) <<
- TDI_TDO_HEADER_SECOND_BYTE_SHIFT);
-
- /*
- * Program the last part of IO scan chain write TDI_TDO packet
- * header (2 bytes) to scan manager
- */
- writel(tdi_tdo_header, &scan_manager_base->fifo_double_byte);
+ scan_mgr_jtag_io(JTAG_BP_INSN | JTAG_BP_2BYTE, 0x0,
+ io_scan_chain_data_residual - 1);
for (i = 0; i < io_program_iter; i++) {
/*
* write remaining scan chain data into scan
* manager WFIFO with 4 bytes write
- */
- writel(iocsr_scan_chain[index + i],
- &scan_manager_base->fifo_quad_byte);
+ */
+ scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0,
+ iocsr_scan_chain[index++]);
}
- index += io_program_iter;
residual = io_scan_chain_data_residual &
IO_SCAN_CHAIN_32BIT_MASK;
@@ -176,8 +199,8 @@
* write the last 4B scan chain data
* into scan manager WFIFO
*/
- writel(iocsr_scan_chain[index],
- &scan_manager_base->fifo_quad_byte);
+ scan_mgr_jtag_io(JTAG_BP_4BYTE, 0x0,
+ iocsr_scan_chain[index]);
} else {
/*
* write the remaining 1 - 3 bytes scan chain
@@ -189,9 +212,8 @@
* glitch)
*/
for (i = 0; i < residual; i += 8) {
- writel(((iocsr_scan_chain[index] >> i)
- & IO_SCAN_CHAIN_BYTE_MASK),
- &scan_manager_base->fifo_single_byte);
+ scan_mgr_jtag_io(0, 0x0,
+ iocsr_scan_chain[index] >> i);
}
}