[PATCH] pinctrl/sunxi: adding input-debounce-ns property

[Marjan Pascolo]

On Allwinner SoC interrupt debounce can be controlled by two oscillator
(32KHz and 24MHz) and a prescale divider.
Oscillator and prescale divider are set through
device tree property "input-debounce" which have 1uS accuracy.
For acheive nS precision a new device tree poperty is made
named "input-debounce-ns".
"input-debounce-ns" is checked only if "input-debounce"
property is not defined.


Suggested-by: Maxime Ripard <maxime@xxxxxxxxxx>
Signed-off-by: Marjan Pascolo <marjan.pascolo@xxxxxxxxx>
---
---
 .../pinctrl/allwinner,sun4i-a10-pinctrl.yaml  |  9 +++++++
 drivers/pinctrl/sunxi/pinctrl-sunxi.c         | 25 ++++++++++++++++---
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git 
a/Documentation/devicetree/bindings/pinctrl/allwinner,sun4i-a10-pinctrl.yaml 
b/Documentation/devicetree/bindings/pinctrl/allwinner,sun4i-a10-pinctrl.yaml
index 5240487dfe50..346776de3a44 100644
--- 
a/Documentation/devicetree/bindings/pinctrl/allwinner,sun4i-a10-pinctrl.yaml
+++ 
b/Documentation/devicetree/bindings/pinctrl/allwinner,sun4i-a10-pinctrl.yaml
@@ -93,6 +93,15 @@ properties:
     minItems: 1
     maxItems: 5

+  input-debounce-ns:
+    description:
+      Debouncing periods in nanoseconds, one period per interrupt
+      bank found in the controller.
+      Only checked if input-debounce is not present
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 5
+
 patternProperties:
   # It's pretty scary, but the basic idea is that:
   #   - One node name can start with either s- or r- for PRCM nodes,
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c 
b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index dc8d39ae045b..869b6d5743ba 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -1335,14 +1335,31 @@ static int sunxi_pinctrl_setup_debounce(struct 
sunxi_pinctrl *pctl,
     struct clk *hosc, *losc;
     u8 div, src;
     int i, ret;
+    /* Keeping for loop below clean */
+    const char* debounce_prop_name;
+    unsigned long debounce_dividend;

     /* Deal with old DTs that didn't have the oscillators */
     if (of_clk_get_parent_count(node) != 3)
         return 0;

+    /*
+     * Distinguish between simple input-debounce
+     * and new input-debounce-ns
+     */
+
     /* If we don't have any setup, bail out */
-    if (!of_find_property(node, "input-debounce", NULL))
-        return 0;
+    if (!of_find_property(node, "input-debounce", NULL)) {
+        if(!of_find_property(node, "input-debounce-ns", NULL)) {
+            return 0;
+        } else {
+            debounce_prop_name="input-debounce-ns";
+            debounce_dividend=NSEC_PER_SEC;
+        }
+    } else {
+        debounce_prop_name="input-debounce";
+        debounce_dividend=USEC_PER_SEC;
+    }

     losc = devm_clk_get(pctl->dev, "losc");
     if (IS_ERR(losc))
@@ -1356,7 +1373,7 @@ static int sunxi_pinctrl_setup_debounce(struct 
sunxi_pinctrl *pctl,
         unsigned long debounce_freq;
         u32 debounce;

-        ret = of_property_read_u32_index(node, "input-debounce",
+        ret = of_property_read_u32_index(node, debounce_prop_name,
                          i, &debounce);
         if (ret)
             return ret;
@@ -1364,7 +1381,7 @@ static int sunxi_pinctrl_setup_debounce(struct 
sunxi_pinctrl *pctl,
         if (!debounce)
             continue;

-        debounce_freq = DIV_ROUND_CLOSEST(USEC_PER_SEC, debounce);
+        debounce_freq = DIV_ROUND_CLOSEST(debounce_dividend, debounce);
         losc_div = sunxi_pinctrl_get_debounce_div(losc,
                               debounce_freq,
                               &losc_diff);
--
2.22.0.windows.1