@@ -13,6 +13,7 @@
*/
#include <linux/bitops.h>
+#include <linux/limits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
@@ -34,12 +35,24 @@
#define WDOG_CURRENT_COUNT_REG_OFFSET 0x08
#define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c
#define WDOG_COUNTER_RESTART_KICK_VALUE 0x76
+#define WDOG_COMP_PARAMS_1_REG_OFFSET 0xf4
+#define WDOG_COMP_PARAMS_1_USE_FIX_TOP BIT(6)
-/* The maximum TOP (timeout period) value that can be set in the watchdog. */
-#define DW_WDT_MAX_TOP 15
+/* There are sixteen TOPs (timeout periods) that can be set in the watchdog. */
+#define DW_WDT_NUM_TOPS 16
+#define DW_WDT_FIX_TOP(_idx) (1U << (16 + _idx))
#define DW_WDT_DEFAULT_SECONDS 30
+static const u32 dw_wdt_fix_tops[DW_WDT_NUM_TOPS] = {
+ DW_WDT_FIX_TOP(0), DW_WDT_FIX_TOP(1), DW_WDT_FIX_TOP(2),
+ DW_WDT_FIX_TOP(3), DW_WDT_FIX_TOP(4), DW_WDT_FIX_TOP(5),
+ DW_WDT_FIX_TOP(6), DW_WDT_FIX_TOP(7), DW_WDT_FIX_TOP(8),
+ DW_WDT_FIX_TOP(9), DW_WDT_FIX_TOP(10), DW_WDT_FIX_TOP(11),
+ DW_WDT_FIX_TOP(12), DW_WDT_FIX_TOP(13), DW_WDT_FIX_TOP(14),
+ DW_WDT_FIX_TOP(15)
+};
+
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
@@ -49,6 +62,8 @@ struct dw_wdt {
void __iomem *regs;
struct clk *clk;
unsigned long rate;
+ unsigned int max_top;
+ unsigned int timeouts[DW_WDT_NUM_TOPS];
struct watchdog_device wdd;
struct reset_control *rst;
/* Save/restore */
@@ -64,20 +79,68 @@ static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt)
WDOG_CONTROL_REG_WDT_EN_MASK;
}
-static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top)
+static unsigned int dw_wdt_find_best_top(struct dw_wdt *dw_wdt,
+ unsigned int timeout, u32 *top)
{
+ u32 diff = UINT_MAX, tmp;
+ int idx;
+
/*
- * There are 16 possible timeout values in 0..15 where the number of
- * cycles is 2 ^ (16 + i) and the watchdog counts down.
+ * In general case of non-fixed timeout values they can be arranged in
+ * any order so we have to traverse all the array values. We also try
+ * to find a closest timeout number and make sure its value is greater
+ * than the requested timeout. Note we'll return a maximum timeout
+ * if reachable value couldn't be found.
*/
- return (1U << (16 + top)) / dw_wdt->rate;
+ for (*top = dw_wdt->max_top, idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
+ if (dw_wdt->timeouts[idx] < timeout)
+ continue;
+
+ tmp = dw_wdt->timeouts[idx] - timeout;
+ if (tmp < diff) {
+ diff = tmp;
+ *top = idx;
+ }
+ }
+
+ return dw_wdt->timeouts[*top];
+}
+
+static unsigned int dw_wdt_find_min_timeout(struct dw_wdt *dw_wdt)
+{
+ u32 min_timeout = UINT_MAX, top;
+ int idx;
+
+ for (top = 0, idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
+ if (dw_wdt->timeouts[idx] <= min_timeout) {
+ min_timeout = dw_wdt->timeouts[idx];
+ top = idx;
+ }
+ }
+
+ return dw_wdt->timeouts[top];
+}
+
+static unsigned int dw_wdt_find_max_top(struct dw_wdt *dw_wdt, u32 *top)
+{
+ u32 max_timeout = 0;
+ int idx;
+
+ for (*top = 0, idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
+ if (dw_wdt->timeouts[idx] >= max_timeout) {
+ max_timeout = dw_wdt->timeouts[idx];
+ *top = idx;
+ }
+ }
+
+ return dw_wdt->timeouts[*top];
}
-static int dw_wdt_get_top(struct dw_wdt *dw_wdt)
+static unsigned int dw_wdt_get_timeout(struct dw_wdt *dw_wdt)
{
int top = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
- return dw_wdt_top_in_seconds(dw_wdt, top);
+ return dw_wdt->timeouts[top];
}
static int dw_wdt_ping(struct watchdog_device *wdd)
@@ -90,20 +153,13 @@ static int dw_wdt_ping(struct watchdog_device *wdd)
return 0;
}
-static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
+static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int req)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
- int i, top_val = DW_WDT_MAX_TOP;
+ unsigned int timeout;
+ u32 top;
- /*
- * Iterate over the timeout values until we find the closest match. We
- * always look for >=.
- */
- for (i = 0; i <= DW_WDT_MAX_TOP; ++i)
- if (dw_wdt_top_in_seconds(dw_wdt, i) >= top_s) {
- top_val = i;
- break;
- }
+ timeout = dw_wdt_find_best_top(dw_wdt, req * MSEC_PER_SEC, &top);
/*
* Set the new value in the watchdog. Some versions of dw_wdt
@@ -111,7 +167,7 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
* CP_WDT_DUAL_TOP in WDT_COMP_PARAMS_1). On those we
* effectively get a pat of the watchdog right here.
*/
- writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
+ writel(top | top << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
/*
@@ -119,10 +175,10 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
* kernel(watchdog_dev.c) helps to feed watchdog before
* wdd->max_hw_heartbeat_ms
*/
- if (top_s * 1000 <= wdd->max_hw_heartbeat_ms)
- wdd->timeout = dw_wdt_top_in_seconds(dw_wdt, top_val);
+ if (req * MSEC_PER_SEC > wdd->max_hw_heartbeat_ms)
+ wdd->timeout = req;
else
- wdd->timeout = top_s;
+ wdd->timeout = timeout / MSEC_PER_SEC;
return 0;
}
@@ -238,6 +294,41 @@ static int dw_wdt_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume);
+static void dw_wdt_init_timeouts(struct dw_wdt *dw_wdt, struct device *dev)
+{
+ u32 data, of_tops[DW_WDT_NUM_TOPS];
+ const u32 *tops;
+ int ret, idx;
+
+ /*
+ * Retrieve custom or fixed counter values depending on the
+ * WDT_USE_FIX_TOP flag found in the component specific parameters
+ * #1 register.
+ */
+ data = readl(dw_wdt->regs + WDOG_COMP_PARAMS_1_REG_OFFSET);
+ if (data & WDOG_COMP_PARAMS_1_USE_FIX_TOP) {
+ tops = dw_wdt_fix_tops;
+ } else {
+ ret = of_property_read_variable_u32_array(dev_of_node(dev),
+ "snps,watchdog-tops", of_tops, DW_WDT_NUM_TOPS,
+ DW_WDT_NUM_TOPS);
+ if (ret < 0) {
+ dev_warn(dev, "No valid TOPs array specified\n");
+ tops = dw_wdt_fix_tops;
+ } else {
+ tops = of_tops;
+ }
+ }
+
+ /*
+ * We'll keep the timeout values in ms to approximate requested
+ * timeouts with better accuracy.
+ */
+ for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx)
+ dw_wdt->timeouts[idx] =
+ mult_frac(tops[idx], MSEC_PER_SEC, dw_wdt->rate);
+}
+
static int dw_wdt_drv_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -275,12 +366,14 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
reset_control_deassert(dw_wdt->rst);
+ dw_wdt_init_timeouts(dw_wdt, dev);
+
wdd = &dw_wdt->wdd;
wdd->info = &dw_wdt_ident;
wdd->ops = &dw_wdt_ops;
- wdd->min_timeout = 1;
+ wdd->min_timeout = dw_wdt_find_min_timeout(dw_wdt) / MSEC_PER_SEC;
wdd->max_hw_heartbeat_ms =
- dw_wdt_top_in_seconds(dw_wdt, DW_WDT_MAX_TOP) * 1000;
+ dw_wdt_find_max_top(dw_wdt, &dw_wdt->max_top);
wdd->parent = dev;
watchdog_set_drvdata(wdd, dw_wdt);
@@ -293,7 +386,7 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
* devicetree.
*/
if (dw_wdt_is_enabled(dw_wdt)) {
- wdd->timeout = dw_wdt_get_top(dw_wdt);
+ wdd->timeout = dw_wdt_get_timeout(dw_wdt) / MSEC_PER_SEC;
set_bit(WDOG_HW_RUNNING, &wdd->status);
} else {
wdd->timeout = DW_WDT_DEFAULT_SECONDS;