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 <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Emilio López <emilio@elopez.com.ar>
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index d4cf297..335c987 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -411,6 +411,102 @@
/**
+ * 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
*/