clk: socfpga: Add a second parent option for the dbg_base_clk

From: Dinh Nguyen <[email protected]>

The debug base clock can be bypassed from the main PLL to the OSC1 clock. The bypass register is the staysoc1(0x10) register that is in the clock manager.

This patch adds the option to get the correct parent for the debug base clock.

Signed-off-by Dinh Nguyen <[email protected]>

---
v2: Update socfpga_periph_init to support multiple parents

---
 arch/arm/boot/dts/socfpga.dtsi   |    2 +-
 drivers/clk/socfpga/clk-periph.c |   21 +++++++++++++++++----
 drivers/clk/socfpga/clk.h        |    1 +
 3 files changed, 19 insertions(+), 5 deletions(-)

arch/arm/boot/dts/socfpga.dtsi +1 -1

index 291eff1..26d755b 100644
@@ -139,7 +139,7 @@
                                                dbg_base_clk: dbg_base_clk {
                                                        #clock-cells = <0>;
                                                        compatible = "altr,socfpga-perip-clk";
-                                                       clocks = <&main_pll>;
+                                                       clocks = <&main_pll>, <&osc1>;
                                                        div-reg = <0xe8 0 9>;
                                                        reg = <0x50>;
                                                };

drivers/clk/socfpga/clk-periph.c +17 -4

index 46531c3..9b64847 100644
@@ -45,8 +45,17 @@ static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
        return parent_rate / div;
 }
 
+static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
+{
+       u32 clk_src;
+
+       clk_src = readl(clk_mgr_base_addr + CLKMGR_DBCTRL);
+       return clk_src & 0x1;
+}
+
 static const struct clk_ops periclk_ops = {
        .recalc_rate = clk_periclk_recalc_rate,
+       .get_parent = clk_periclk_get_parent,
 };
 
 static __init void __socfpga_periph_init(struct device_node *node,

@@ -56,11 +65,12 @@ static __init void __socfpga_periph_init(struct device_node *node,
        struct clk *clk;
        struct socfpga_periph_clk *periph_clk;
        const char *clk_name = node->name;
-       const char *parent_name;
+       const char *parent_name[SOCFPGA_MAX_PARENTS];
        struct clk_init_data init;
        int rc;
        u32 fixed_div;
        u32 div_reg[3];
+       int i = 0;
 
        of_property_read_u32(node, "reg", &reg);
 

@@ -90,9 +100,12 @@ static __init void __socfpga_periph_init(struct device_node *node,
        init.name = clk_name;
        init.ops = ops;
        init.flags = 0;
-       parent_name = of_clk_get_parent_name(node, 0);
-       init.parent_names = &parent_name;
-       init.num_parents = 1;
+       while (i < SOCFPGA_MAX_PARENTS && (parent_name[i] =
+                       of_clk_get_parent_name(node, i)) != NULL)
+               i++;
+
+       init.parent_names = parent_name;
+       init.num_parents = i;
 
        periph_clk->hw.hw.init = &init;
 

drivers/clk/socfpga/clk.h +1 -0

index d291f60..d036de2 100644
@@ -23,6 +23,7 @@
 /* Clock Manager offsets */
 #define CLKMGR_CTRL            0x0
 #define CLKMGR_BYPASS          0x4
+#define CLKMGR_DBCTRL          0x10
 #define CLKMGR_L4SRC           0x70
 #define CLKMGR_PERPLL_SRC      0xAC
 

Signature · 1 line

1.7.9.5

Quoting dinguyen at altera.com (2014-06-13 20:00:35)

Quoted 9 lines

From: Dinh Nguyen <[email protected]>

The debug base clock can be bypassed from the main PLL to the OSC1 clock. The bypass register is the staysoc1(0x10) register that is in the clock manager.

This patch adds the option to get the correct parent for the debug base clock.

Quoted 1 line

Signed-off-by Dinh Nguyen <[email protected]>

Looks good to me.

Regards,
Mike