From aa5659ac65b4eefc1685f9d520279c4ee553789a Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sat, 1 Aug 2015 02:48:03 +0200 Subject: [PATCH] arm: socfpga: scan: Clean up scan_chain_engine_is_idle() Rework this function so it's clear that it is only polling for certain bits to be cleared. Add kerneldoc. Fix it's return value to be either 0 on success and -ETIMEDOUT on error and propagate this through the scan manager code. Signed-off-by: Marek Vasut Acked-by: Dinh Nguyen --- arch/arm/mach-socfpga/include/mach/scan_manager.h | 9 ---- arch/arm/mach-socfpga/scan_manager.c | 53 +++++++++++++++-------- 2 files changed, 34 insertions(+), 28 deletions(-) diff --git a/arch/arm/mach-socfpga/include/mach/scan_manager.h b/arch/arm/mach-socfpga/include/mach/scan_manager.h index 94ad50b..ddf8790 100644 --- a/arch/arm/mach-socfpga/include/mach/scan_manager.h +++ b/arch/arm/mach-socfpga/include/mach/scan_manager.h @@ -59,15 +59,6 @@ struct socfpga_scan_manager { /* Position of second command byte for TDI_TDO packet */ #define TDI_TDO_HEADER_SECOND_BYTE_SHIFT 8 -/* - * Maximum polling loop to wait for IO scan chain engine - * becomes idle to prevent infinite loop - */ -#define SCAN_MAX_DELAY 100 - -#define SCANMGR_STAT_ACTIVE_GET(x) (((x) & 0x80000000) >> 31) -#define SCANMGR_STAT_WFIFOCNT_GET(x) (((x) & 0x70000000) >> 28) - int scan_mgr_configure_iocsr(void); int iocsr_get_config_table(const unsigned int chain_id, const unsigned long **table, diff --git a/arch/arm/mach-socfpga/scan_manager.c b/arch/arm/mach-socfpga/scan_manager.c index ec0c630..3f244b9 100644 --- a/arch/arm/mach-socfpga/scan_manager.c +++ b/arch/arm/mach-socfpga/scan_manager.c @@ -5,10 +5,22 @@ */ #include +#include #include #include #include +/* + * Maximum polling loop to wait for IO scan chain engine becomes idle + * to prevent infinite loop. It is important that this is NOT changed + * to delay using timer functions, since at the time this function is + * called, timer might not yet be inited. + */ +#define SCANMGR_MAX_DELAY 100 + +#define SCANMGR_STAT_ACTIVE (1 << 31) +#define SCANMGR_STAT_WFIFOCNT_MASK 0x70000000 + DECLARE_GLOBAL_DATA_PTR; static const struct socfpga_scan_manager *scan_manager_base = @@ -16,26 +28,26 @@ static const struct socfpga_scan_manager *scan_manager_base = static const struct socfpga_freeze_controller *freeze_controller_base = (void *)(SOCFPGA_SYSMGR_ADDRESS + SYSMGR_FRZCTRL_ADDRESS); -/* +/** + * scan_chain_engine_is_idle() - Check if the JTAG scan chain is idle + * @max_iter: Maximum number of iterations to wait for idle + * * Function to check IO scan chain engine status and wait if the engine is * is active. Poll the IO scan chain engine till maximum iteration reached. */ -static inline uint32_t scan_chain_engine_is_idle(uint32_t max_iter) +static u32 scan_chain_engine_is_idle(u32 max_iter) { - uint32_t scanmgr_status; - - scanmgr_status = readl(&scan_manager_base->stat); + const u32 mask = SCANMGR_STAT_ACTIVE | SCANMGR_STAT_WFIFOCNT_MASK; + u32 status; - /* Poll the engine until the scan engine is inactive */ - while (SCANMGR_STAT_ACTIVE_GET(scanmgr_status) || - (SCANMGR_STAT_WFIFOCNT_GET(scanmgr_status) > 0)) { - max_iter--; - if (max_iter > 0) - scanmgr_status = readl(&scan_manager_base->stat); - else + /* Poll the engine until the scan engine is inactive. */ + do { + status = readl(&scan_manager_base->stat); + if (!(status & mask)) return 0; - } - return 1; + } while (max_iter--); + + return -ETIMEDOUT; } /** @@ -70,8 +82,9 @@ static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id) * Check if the scan chain engine is inactive and the * WFIFO is empty before enabling the IO scan chain */ - if (!scan_chain_engine_is_idle(SCAN_MAX_DELAY)) - return 1; + ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY); + if (ret) + return ret; /* * Enable IO Scan chain based on scan chain id @@ -114,7 +127,8 @@ static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id) * Check if the scan chain engine has completed the * IO scan chain data shifting */ - if (!scan_chain_engine_is_idle(SCAN_MAX_DELAY)) + ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY); + if (ret) goto error; } @@ -185,7 +199,8 @@ static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id) * Check if the scan chain engine has completed the * IO scan chain data shifting */ - if (!scan_chain_engine_is_idle(SCAN_MAX_DELAY)) + ret = scan_chain_engine_is_idle(SCANMGR_MAX_DELAY); + if (ret) goto error; } @@ -196,7 +211,7 @@ static int scan_mgr_io_scan_chain_prg(const unsigned int io_scan_chain_id) error: /* Disable IO Scan chain when error detected */ clrbits_le32(&scan_manager_base->en, 1 << io_scan_chain_id); - return 1; + return ret; } int scan_mgr_configure_iocsr(void) -- 2.7.4