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authorLinus Torvalds <torvalds@linux-foundation.org>2014-06-16 02:02:20 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-16 02:02:20 (GMT)
commitdd1845af24a47b70cf84c29126698884f740ff9c (patch)
treefa12809d854d18ba36a568c21d57ceff43617af1 /drivers/clk/sunxi/clk-a20-gmac.c
parentb55b39020289f225bf2455349ce1a67372a0baa9 (diff)
parentb640a6037c9ecd1f0ad23a8e9b4ca5f5b4112508 (diff)
downloadlinux-dd1845af24a47b70cf84c29126698884f740ff9c.tar.xz
Merge tag 'clk-for-linus-3.16-part2' of git://git.linaro.org/people/mike.turquette/linux
Pull more clock framework updates from Mike Turquette: "This contains the second half the of the clk changes for 3.16. They are simply fixes and code refactoring for the OMAP clock drivers. The sunxi clock driver changes include splitting out the one mega-driver into several smaller pieces and adding support for the A31 SoC clocks" * tag 'clk-for-linus-3.16-part2' of git://git.linaro.org/people/mike.turquette/linux: (25 commits) clk: sunxi: document PRCM clock compatible strings clk: sunxi: add PRCM (Power/Reset/Clock Management) clks support clk: sun6i: Protect SDRAM gating bit clk: sun6i: Protect CPU clock clk: sunxi: Rework clock protection code clk: sunxi: Move the GMAC clock to a file of its own clk: sunxi: Move the 24M oscillator to a file of its own clk: sunxi: Remove calls to clk_put clk: sunxi: document new A31 USB clock compatible clk: sunxi: Implement A31 USB clock ARM: dts: OMAP5/DRA7: use omap5-mpu-dpll-clock capable of dealing with higher frequencies CLK: TI: dpll: support OMAP5 MPU DPLL that need special handling for higher frequencies ARM: OMAP5+: dpll: support Duty Cycle Correction(DCC) CLK: TI: clk-54xx: Set the rate for dpll_abe_m2x2_ck CLK: TI: Driver for DRA7 ATL (Audio Tracking Logic) dt:/bindings: DRA7 ATL (Audio Tracking Logic) clock bindings ARM: dts: dra7xx-clocks: Correct name for atl clkin3 clock CLK: TI: gate: add composite interface clock to OMAP2 only build ARM: OMAP2: clock: add DT boot support for cpufreq_ck CLK: TI: OMAP2: add clock init support ...
Diffstat (limited to 'drivers/clk/sunxi/clk-a20-gmac.c')
-rw-r--r--drivers/clk/sunxi/clk-a20-gmac.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-a20-gmac.c b/drivers/clk/sunxi/clk-a20-gmac.c
new file mode 100644
index 0000000..633ddc4
--- /dev/null
+++ b/drivers/clk/sunxi/clk-a20-gmac.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2013 Emilio López
+ * Emilio López <emilio@elopez.com.ar>
+ *
+ * Copyright 2013 Chen-Yu Tsai
+ * Chen-Yu Tsai <wens@csie.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+static DEFINE_SPINLOCK(gmac_lock);
+
+/**
+ * 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 = &gmac_lock;
+ mux->reg = reg;
+ mux->mask = SUN7I_A20_GMAC_MASK;
+ mux->flags = CLK_MUX_INDEX_BIT;
+ mux->lock = &gmac_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);