Commit 4105f19f authored by Serge Semin's avatar Serge Semin Committed by Wim Van Sebroeck
Browse files

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: default avatarSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
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: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
parent 46a19463

drivers/watchdog/dw_wdt.c

+68 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/platform_device.h>

#include <linux/reset.h>

#include <linux/watchdog.h>

#include <linux/debugfs.h>



#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);