clk: ti: add generic support for clock latching

Certain clocks require latching to be done, so that the actual
settings get updated on the HW that generates the clock signal.
One example of such a clock is the dra76x GMAC DPLL H14 output,
which requires its divider settings to be latched when updated.

Signed-off-by: Tero Kristo <t-kristo@ti.com>

2 files changed, 16 insertions, 0 deletions

diff --git a/drivers/clk/ti/clk.c b/drivers/clk/ti/clk.c
index 4efa2c9ea908..7d22e1af2247 100644
--- a/drivers/clk/ti/clk.c
+++ b/drivers/clk/ti/clk.c
@@ -275,6 +275,20 @@ int ti_clk_get_reg_addr(struct device_node *node, int index,
 	return 0;
 }
 
+void ti_clk_latch(struct clk_omap_reg *reg, s8 shift)
+{
+	u32 latch;
+
+	if (shift < 0)
+		return;
+
+	latch = 1 << shift;
+
+	ti_clk_ll_ops->clk_rmw(latch, latch, reg);
+	ti_clk_ll_ops->clk_rmw(0, latch, reg);
+	ti_clk_ll_ops->clk_readl(reg); /* OCP barrier */
+}
+
 /**
  * omap2_clk_provider_init - init master clock provider
  * @parent: master node
diff --git a/drivers/clk/ti/clock.h b/drivers/clk/ti/clock.h
index d9b43bfc2532..2f8af8fd886a 100644
--- a/drivers/clk/ti/clock.h
+++ b/drivers/clk/ti/clock.h
@@ -194,6 +194,8 @@ struct clk *ti_clk_register(struct device *dev, struct clk_hw *hw,
 int ti_clk_add_alias(struct device *dev, struct clk *clk, const char *con);
 void ti_clk_add_aliases(void);
 
+void ti_clk_latch(struct clk_omap_reg *reg, s8 shift);
+
 struct clk_hw *ti_clk_build_component_mux(struct ti_clk_mux *setup);
 
 int ti_clk_parse_divider_data(int *div_table, int num_dividers, int max_div,