clk: bcm281xx: add clock hysteresis support
Add support for clock gate hysteresis control. For now, if it's
defined for a clock, it's enabled.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c
index 7d90c34..d603c4e 100644
--- a/drivers/clk/bcm/clk-kona.c
+++ b/drivers/clk/bcm/clk-kona.c
@@ -527,6 +527,35 @@
return -EIO;
}
+/* Hysteresis operations */
+
+/*
+ * If a clock gate requires a turn-off delay it will have
+ * "hysteresis" register bits defined. The first, if set, enables
+ * the delay; and if enabled, the second bit determines whether the
+ * delay is "low" or "high" (1 means high). For now, if it's
+ * defined for a clock, we set it.
+ */
+static bool hyst_init(struct ccu_data *ccu, struct bcm_clk_hyst *hyst)
+{
+ u32 offset;
+ u32 reg_val;
+ u32 mask;
+
+ if (!hyst_exists(hyst))
+ return true;
+
+ offset = hyst->offset;
+ mask = (u32)1 << hyst->en_bit;
+ mask |= (u32)1 << hyst->val_bit;
+
+ reg_val = __ccu_read(ccu, offset);
+ reg_val |= mask;
+ __ccu_write(ccu, offset, reg_val);
+
+ return true;
+}
+
/* Trigger operations */
/*
@@ -1131,6 +1160,10 @@
pr_err("%s: error initializing gate for %s\n", __func__, name);
return false;
}
+ if (!hyst_init(ccu, &peri->hyst)) {
+ pr_err("%s: error initializing hyst for %s\n", __func__, name);
+ return false;
+ }
if (!div_init(ccu, &peri->gate, &peri->div, &peri->trig)) {
pr_err("%s: error initializing divider for %s\n", __func__,
name);