cregit-Linux how code gets into the kernel

Release 4.7 drivers/clk/sunxi/clk-a20-gmac.c

/*
 * 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/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 u32 sun7i_a20_gmac_mux_table[SUN7I_A20_GMAC_PARENTS] = {
	0x00, /* Select mii_phy_tx_clk */
	0x02, /* Select gmac_int_tx_clk */
};


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 __iomem *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 */ if (of_clk_parent_fill(node, parents, 2) != 2) 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->table = sun7i_a20_gmac_mux_table; 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); return; iounmap_reg: iounmap(reg); free_gate: kfree(gate); free_mux: kfree(mux); }

Contributors

PersonTokensPropCommitsCommitProp
maxime ripardmaxime ripard24996.51%125.00%
dinh nguyendinh nguyen62.33%125.00%
hans de goedehans de goede20.78%125.00%
emilio lopezemilio lopez10.39%125.00%
Total258100.00%4100.00%

CLK_OF_DECLARE(sun7i_a20_gmac, "allwinner,sun7i-a20-gmac-clk", sun7i_a20_gmac_clk_setup);

Overall Contributors

PersonTokensPropCommitsCommitProp
maxime ripardmaxime ripard29092.06%125.00%
hans de goedehans de goede185.71%125.00%
dinh nguyendinh nguyen61.90%125.00%
emilio lopezemilio lopez10.32%125.00%
Total315100.00%4100.00%
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