[PATCH v2 02/10] clk: sunxi: Add support for multiple parents to gates

[Jens Kuske]

Some newer sunxi SoCs (A83T, H3) don't have individual registers for
AHB1, APB1 and APB2 gates anymore, but one big bus gates area where each
gate can have a different parent.

The current clock driver sets the same parent for all gates in a group.
This commit adds a new parents field to the gates_data structure, which
allows us to specify an array of parent indices for every single gate.

Signed-off-by: Jens Kuske <jenskuske at gmail.com>
---
 drivers/clk/sunxi/clk-sunxi.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 9a82f17..17cba4d 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -898,6 +898,8 @@ static void __init sunxi_divider_clk_setup(struct device_node *node,
 
 struct gates_data {
 	DECLARE_BITMAP(mask, SUNXI_GATES_MAX_SIZE);
+	/* If used, ARRAY_SIZE(parents) has to be >= bitmap_weight(mask) */
+	const u8 *parents;
 };
 
 static const struct gates_data sun4i_axi_gates_data __initconst = {
@@ -1000,16 +1002,21 @@ static void __init sunxi_gates_clk_setup(struct device_node *node,
 					 struct gates_data *data)
 {
 	struct clk_onecell_data *clk_data;
+	const char *parents[SUNXI_MAX_PARENTS];
 	const char *clk_parent;
 	const char *clk_name;
 	void __iomem *reg;
+	int npar = 0;
 	int qty;
 	int i = 0;
 	int j = 0;
 
 	reg = of_iomap(node, 0);
 
-	clk_parent = of_clk_get_parent_name(node, 0);
+	while (npar < SUNXI_MAX_PARENTS &&
+	       (parents[npar] = of_clk_get_parent_name(node, npar)) != NULL)
+		npar++;
+	clk_parent = parents[0];
 
 	/* Worst-case size approximation and memory allocation */
 	qty = find_last_bit(data->mask, SUNXI_GATES_MAX_SIZE);
@@ -1026,6 +1033,9 @@ static void __init sunxi_gates_clk_setup(struct device_node *node,
 		of_property_read_string_index(node, "clock-output-names",
 					      j, &clk_name);
 
+		if (data->parents && !WARN_ON(data->parents[j] >= npar))
+			clk_parent = parents[data->parents[j]];
+
 		clk_data->clks[i] = clk_register_gate(NULL, clk_name,
 						      clk_parent, 0,
 						      reg + 4 * (i/32), i % 32,
-- 
2.4.0