From 62d1e7823d9c3b454dcbffd58f35c5fa96172644 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Mon, 30 Nov 2015 17:54:56 +0100 Subject: clk: axi-clkgen: Add multi-parent support The clock generator has two clock inputs that can be used as the reference clock. Add support for switching between them at runtime. Signed-off-by: Lars-Peter Clausen Signed-off-by: Stephen Boyd --- .../devicetree/bindings/clock/axi-clkgen.txt | 5 ++- drivers/clk/clk-axi-clkgen.c | 40 ++++++++++++++++++---- 2 files changed, 38 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/clock/axi-clkgen.txt b/Documentation/devicetree/bindings/clock/axi-clkgen.txt index 20e1704e7df2..fb40da303d25 100644 --- a/Documentation/devicetree/bindings/clock/axi-clkgen.txt +++ b/Documentation/devicetree/bindings/clock/axi-clkgen.txt @@ -8,7 +8,10 @@ Required properties: - compatible : shall be "adi,axi-clkgen-1.00.a" or "adi,axi-clkgen-2.00.a". - #clock-cells : from common clock binding; Should always be set to 0. - reg : Address and length of the axi-clkgen register set. -- clocks : Phandle and clock specifier for the parent clock. +- clocks : Phandle and clock specifier for the parent clock(s). This must + either reference one clock if only the first clock input is connected or two + if both clock inputs are connected. For the later case the clock connected + to the first input must be specified first. Optional properties: - clock-output-names : From common clock binding. diff --git a/drivers/clk/clk-axi-clkgen.c b/drivers/clk/clk-axi-clkgen.c index 8dedc600e711..9a0744c9947c 100644 --- a/drivers/clk/clk-axi-clkgen.c +++ b/drivers/clk/clk-axi-clkgen.c @@ -17,6 +17,7 @@ #include #define AXI_CLKGEN_V2_REG_RESET 0x40 +#define AXI_CLKGEN_V2_REG_CLKSEL 0x44 #define AXI_CLKGEN_V2_REG_DRP_CNTRL 0x70 #define AXI_CLKGEN_V2_REG_DRP_STATUS 0x74 @@ -349,12 +350,33 @@ static void axi_clkgen_disable(struct clk_hw *clk_hw) axi_clkgen_mmcm_enable(axi_clkgen, false); } +static int axi_clkgen_set_parent(struct clk_hw *clk_hw, u8 index) +{ + struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); + + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, index); + + return 0; +} + +static u8 axi_clkgen_get_parent(struct clk_hw *clk_hw) +{ + struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); + unsigned int parent; + + axi_clkgen_read(axi_clkgen, AXI_CLKGEN_V2_REG_CLKSEL, &parent); + + return parent; +} + static const struct clk_ops axi_clkgen_ops = { .recalc_rate = axi_clkgen_recalc_rate, .round_rate = axi_clkgen_round_rate, .set_rate = axi_clkgen_set_rate, .enable = axi_clkgen_enable, .disable = axi_clkgen_disable, + .set_parent = axi_clkgen_set_parent, + .get_parent = axi_clkgen_get_parent, }; static const struct of_device_id axi_clkgen_ids[] = { @@ -370,10 +392,11 @@ static int axi_clkgen_probe(struct platform_device *pdev) const struct of_device_id *id; struct axi_clkgen *axi_clkgen; struct clk_init_data init; - const char *parent_name; + const char *parent_names[2]; const char *clk_name; struct resource *mem; struct clk *clk; + unsigned int i; if (!pdev->dev.of_node) return -ENODEV; @@ -391,19 +414,24 @@ static int axi_clkgen_probe(struct platform_device *pdev) if (IS_ERR(axi_clkgen->base)) return PTR_ERR(axi_clkgen->base); - parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0); - if (!parent_name) + init.num_parents = of_clk_get_parent_count(pdev->dev.of_node); + if (init.num_parents < 1 || init.num_parents > 2) return -EINVAL; + for (i = 0; i < init.num_parents; i++) { + parent_names[i] = of_clk_get_parent_name(pdev->dev.of_node, i); + if (!parent_names[i]) + return -EINVAL; + } + clk_name = pdev->dev.of_node->name; of_property_read_string(pdev->dev.of_node, "clock-output-names", &clk_name); init.name = clk_name; init.ops = &axi_clkgen_ops; - init.flags = CLK_SET_RATE_GATE; - init.parent_names = &parent_name; - init.num_parents = 1; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; + init.parent_names = parent_names; axi_clkgen_mmcm_enable(axi_clkgen, false); -- cgit v1.2.3