Hi,
On Mon, Feb 03, 2014 at 11:32:19AM +0800, Chen-Yu Tsai wrote:
> 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 <wens@xxxxxxxx>
> ---
> Documentation/devicetree/bindings/clock/sunxi.txt | 26 +++++++
> drivers/clk/sunxi/clk-sunxi.c | 83 +++++++++++++++++++++++
> 2 files changed, 109 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> index 0cf679b..f43b4c0 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 +100,25 @@ 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>;
> + clocks = <&mii_phy_tx_clk>, <&gmac_int_tx_clk>;
You should also document in which order you expect the parents to
be. Or it will probably be easier to just use clock-names here.
> + clock-output-names = "gmac";
> +};
> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> index 736fb60..0b361d2 100644
> --- a/drivers/clk/sunxi/clk-sunxi.c
> +++ b/drivers/clk/sunxi/clk-sunxi.c
> @@ -379,6 +379,89 @@ 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_MAX_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_MAX_PARENTS];
> + void *reg;
> + int i = 0;
> +
> + /* allocate mux and gate clock structs */
> + mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
> + if (!mux)
> + return;
Newline.
> + gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
> + if (!gate) {
> + kfree(mux);
> + return;
> + }
> +
> + reg = of_iomap(node, 0);
You should check for the return code here.
> + of_property_read_string(node, "clock-output-names", &clk_name);
And here too, since you made the clock-output-names property mandatory
> + while (i < SUN7I_A20_GMAC_MAX_PARENTS &&
> + (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
You should check for an error here too, but if you switch to using
clock-names, that will probably be refactored anyway.
> + i++;
> +
> + /* 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, i,
> + &mux->hw, &clk_mux_ops,
> + NULL, NULL,
> + &gate->hw, &clk_gate_ops,
> + 0);
> +
> + if (!IS_ERR(clk)) {
> + of_clk_add_provider(node, of_clk_src_simple_get, clk);
> + clk_register_clkdev(clk, clk_name, NULL);
> + }
> +}
> +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
> */
>
> --
> 1.9.rc1
>
It looks fine otherwise.
Thanks!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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