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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/clk/sunxi/clk-a20-gmac.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/sunxi/clk-a20-gmac.c | 112 |
1 files changed, 112 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 000000000..0b09230a0 --- /dev/null +++ b/drivers/clk/sunxi/clk-a20-gmac.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2013 Emilio López + * Emilio López <emilio@elopez.com.ar> + * + * Copyright 2013 Chen-Yu Tsai + * Chen-Yu Tsai <wens@csie.org> + */ + +#include <linux/clk-provider.h> +#include <linux/io.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); +} +CLK_OF_DECLARE(sun7i_a20_gmac, "allwinner,sun7i-a20-gmac-clk", + sun7i_a20_gmac_clk_setup); |