From 967f938d4b16233fd7596e94803a36161847c6a8 Mon Sep 17 00:00:00 2001 From: Chen-Yu Tsai Date: Mon, 10 Feb 2014 18:35:47 +0800 Subject: [PATCH] clk: sunxi: Add Allwinner A20/A31 GMAC clock unit The Allwinner A20/A31 clock module controls the transmit clock source and interface type of the GMAC ethernet controller. Model this as a single clock for GMAC drivers to use. Signed-off-by: Chen-Yu Tsai --- Documentation/devicetree/bindings/clock/sunxi.txt | 30 +++++++ drivers/clk/sunxi/clk-sunxi.c | 96 +++++++++++++++++++++++ 2 files changed, 126 insertions(+) diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt index 93d003c..0da774c 100644 --- a/Documentation/devicetree/bindings/clock/sunxi.txt +++ b/Documentation/devicetree/bindings/clock/sunxi.txt @@ -37,6 +37,7 @@ Required properties: "allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31 "allwinner,sun4i-mod0-clk" - for the module 0 family of clocks "allwinner,sun7i-a20-out-clk" - for the external output clocks + "allwinner,sun7i-a20-gmac-clk" - for the GMAC clock module on A20/A31 Required properties for all clocks: - reg : shall be the control register address for the clock. @@ -50,6 +51,9 @@ Required properties for all clocks: If the clock module only has one output, the name shall be the module name. +For "allwinner,sun7i-a20-gmac-clk", the parent clocks shall be fixed rate +dummy clocks at 25 MHz and 125 MHz, respectively. See example. + Clock consumers should specify the desired clocks they use with a "clocks" phandle cell. Consumers that are using a gated clock should provide an additional ID in their clock property. This ID is the @@ -96,3 +100,29 @@ mmc0_clk: clk@01c20088 { clocks = <&osc24M>, <&pll6 1>, <&pll5 1>; clock-output-names = "mmc0"; }; + +mii_phy_tx_clk: clk@2 { + #clock-cells = <0>; + compatible = "fixed-clock"; + clock-frequency = <25000000>; + clock-output-names = "mii_phy_tx"; +}; + +gmac_int_tx_clk: clk@3 { + #clock-cells = <0>; + compatible = "fixed-clock"; + clock-frequency = <125000000>; + clock-output-names = "gmac_int_tx"; +}; + +gmac_clk: clk@01c20164 { + #clock-cells = <0>; + compatible = "allwinner,sun7i-a20-gmac-clk"; + reg = <0x01c20164 0x4>; + /* + * The first clock must be fixed at 25MHz; + * the second clock must be fixed at 125MHz + */ + clocks = <&mii_phy_tx_clk>, <&gmac_int_tx_clk>; + clock-output-names = "gmac"; +}; diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c index 0dce6fd..3283179 100644 --- a/drivers/clk/sunxi/clk-sunxi.c +++ b/drivers/clk/sunxi/clk-sunxi.c @@ -404,6 +404,102 @@ static void sun7i_a20_get_out_factors(u32 *freq, u32 parent_rate, /** + * sun7i_a20_gmac_clk_setup - Setup function for A20/A31 GMAC clock module + * + * This clock looks something like this + * ________________________ + * MII TX clock from PHY >-----|___________ _________|----> to GMAC core + * GMAC Int. RGMII TX clk >----|___________\__/__gate---|----> to PHY + * Ext. 125MHz RGMII TX clk >--|__divider__/ | + * |________________________| + * + * The external 125 MHz reference is optional, i.e. GMAC can use its + * internal TX clock just fine. The A31 GMAC clock module does not have + * the divider controls for the external reference. + * + * To keep it simple, let the GMAC use either the MII TX clock for MII mode, + * and its internal TX clock for GMII and RGMII modes. The GMAC driver should + * select the appropriate source and gate/ungate the output to the PHY. + * + * Only the GMAC should use this clock. Altering the clock so that it doesn't + * match the GMAC's operation parameters will result in the GMAC not being + * able to send traffic out. The GMAC driver should set the clock rate and + * enable/disable this clock to configure the required state. The clock + * driver then responds by auto-reparenting the clock. + */ + +#define SUN7I_A20_GMAC_GPIT 2 +#define SUN7I_A20_GMAC_MASK 0x3 +#define SUN7I_A20_GMAC_PARENTS 2 + +static void __init sun7i_a20_gmac_clk_setup(struct device_node *node) +{ + struct clk *clk; + struct clk_mux *mux; + struct clk_gate *gate; + const char *clk_name = node->name; + const char *parents[SUN7I_A20_GMAC_PARENTS]; + void *reg; + + if (of_property_read_string(node, "clock-output-names", &clk_name)) + return; + + /* allocate mux and gate clock structs */ + mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL); + if (!mux) + return; + + gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL); + if (!gate) + goto free_mux; + + /* gmac clock requires exactly 2 parents */ + parents[0] = of_clk_get_parent_name(node, 0); + parents[1] = of_clk_get_parent_name(node, 1); + if (!parents[0] || !parents[1]) + goto free_gate; + + reg = of_iomap(node, 0); + if (!reg) + goto free_gate; + + /* set up gate and fixed rate properties */ + gate->reg = reg; + gate->bit_idx = SUN7I_A20_GMAC_GPIT; + gate->lock = &clk_lock; + mux->reg = reg; + mux->mask = SUN7I_A20_GMAC_MASK; + mux->flags = CLK_MUX_INDEX_BIT; + mux->lock = &clk_lock; + + clk = clk_register_composite(NULL, clk_name, + parents, SUN7I_A20_GMAC_PARENTS, + &mux->hw, &clk_mux_ops, + NULL, NULL, + &gate->hw, &clk_gate_ops, + 0); + + if (IS_ERR(clk)) + goto iounmap_reg; + + of_clk_add_provider(node, of_clk_src_simple_get, clk); + clk_register_clkdev(clk, clk_name, NULL); + + return; + +iounmap_reg: + iounmap(reg); +free_gate: + kfree(gate); +free_mux: + kfree(mux); +} +CLK_OF_DECLARE(sun7i_a20_gmac, "allwinner,sun7i-a20-gmac-clk", + sun7i_a20_gmac_clk_setup); + + + +/** * sunxi_factors_clk_setup() - Setup function for factor clocks */ -- 1.8.5.5