From 4105f19fd0ce51b571f8112457182dfad142768e Mon Sep 17 00:00:00 2001 From: Serge Semin Date: Sat, 30 May 2020 10:35:57 +0300 Subject: [PATCH] watchdog: dw_wdt: Add DebugFS files For the sake of the easier device-driver debug procedure, we added a DebugFS file with the controller registers state. It's available only if kernel is configured with DebugFS support. Signed-off-by: Serge Semin Reviewed-by: Guenter Roeck Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200530073557.22661-8-Sergey.Semin@baikalelectronics.ru Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/dw_wdt.c | 68 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index 7a171920dd21..4fec2c6a3c01 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -28,6 +28,7 @@ #include #include #include +#include #define WDOG_CONTROL_REG_OFFSET 0x00 #define WDOG_CONTROL_REG_WDT_EN_MASK 0x01 @@ -39,8 +40,14 @@ #define WDOG_COUNTER_RESTART_KICK_VALUE 0x76 #define WDOG_INTERRUPT_STATUS_REG_OFFSET 0x10 #define WDOG_INTERRUPT_CLEAR_REG_OFFSET 0x14 +#define WDOG_COMP_PARAMS_5_REG_OFFSET 0xe4 +#define WDOG_COMP_PARAMS_4_REG_OFFSET 0xe8 +#define WDOG_COMP_PARAMS_3_REG_OFFSET 0xec +#define WDOG_COMP_PARAMS_2_REG_OFFSET 0xf0 #define WDOG_COMP_PARAMS_1_REG_OFFSET 0xf4 #define WDOG_COMP_PARAMS_1_USE_FIX_TOP BIT(6) +#define WDOG_COMP_VERSION_REG_OFFSET 0xf8 +#define WDOG_COMP_TYPE_REG_OFFSET 0xfc /* There are sixteen TOPs (timeout periods) that can be set in the watchdog. */ #define DW_WDT_NUM_TOPS 16 @@ -85,6 +92,10 @@ struct dw_wdt { /* Save/restore */ u32 control; u32 timeout; + +#ifdef CONFIG_DEBUG_FS + struct dentry *dbgfs_dir; +#endif }; #define to_dw_wdt(wdd) container_of(wdd, struct dw_wdt, wdd) @@ -484,6 +495,59 @@ static int dw_wdt_init_timeouts(struct dw_wdt *dw_wdt, struct device *dev) return 0; } +#ifdef CONFIG_DEBUG_FS + +#define DW_WDT_DBGFS_REG(_name, _off) \ +{ \ + .name = _name, \ + .offset = _off \ +} + +static const struct debugfs_reg32 dw_wdt_dbgfs_regs[] = { + DW_WDT_DBGFS_REG("cr", WDOG_CONTROL_REG_OFFSET), + DW_WDT_DBGFS_REG("torr", WDOG_TIMEOUT_RANGE_REG_OFFSET), + DW_WDT_DBGFS_REG("ccvr", WDOG_CURRENT_COUNT_REG_OFFSET), + DW_WDT_DBGFS_REG("crr", WDOG_COUNTER_RESTART_REG_OFFSET), + DW_WDT_DBGFS_REG("stat", WDOG_INTERRUPT_STATUS_REG_OFFSET), + DW_WDT_DBGFS_REG("param5", WDOG_COMP_PARAMS_5_REG_OFFSET), + DW_WDT_DBGFS_REG("param4", WDOG_COMP_PARAMS_4_REG_OFFSET), + DW_WDT_DBGFS_REG("param3", WDOG_COMP_PARAMS_3_REG_OFFSET), + DW_WDT_DBGFS_REG("param2", WDOG_COMP_PARAMS_2_REG_OFFSET), + DW_WDT_DBGFS_REG("param1", WDOG_COMP_PARAMS_1_REG_OFFSET), + DW_WDT_DBGFS_REG("version", WDOG_COMP_VERSION_REG_OFFSET), + DW_WDT_DBGFS_REG("type", WDOG_COMP_TYPE_REG_OFFSET) +}; + +static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) +{ + struct device *dev = dw_wdt->wdd.parent; + struct debugfs_regset32 *regset; + + regset = devm_kzalloc(dev, sizeof(*regset), GFP_KERNEL); + if (!regset) + return; + + regset->regs = dw_wdt_dbgfs_regs; + regset->nregs = ARRAY_SIZE(dw_wdt_dbgfs_regs); + regset->base = dw_wdt->regs; + + dw_wdt->dbgfs_dir = debugfs_create_dir(dev_name(dev), NULL); + + debugfs_create_regset32("registers", 0444, dw_wdt->dbgfs_dir, regset); +} + +static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) +{ + debugfs_remove_recursive(dw_wdt->dbgfs_dir); +} + +#else /* !CONFIG_DEBUG_FS */ + +static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) {} +static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) {} + +#endif /* !CONFIG_DEBUG_FS */ + static int dw_wdt_drv_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -607,6 +671,8 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) if (ret) goto out_disable_pclk; + dw_wdt_dbgfs_init(dw_wdt); + return 0; out_disable_pclk: @@ -621,6 +687,8 @@ static int dw_wdt_drv_remove(struct platform_device *pdev) { struct dw_wdt *dw_wdt = platform_get_drvdata(pdev); + dw_wdt_dbgfs_clear(dw_wdt); + watchdog_unregister_device(&dw_wdt->wdd); reset_control_assert(dw_wdt->rst); clk_disable_unprepare(dw_wdt->pclk);