diff options
Diffstat (limited to 'drivers/clk/zynqmp/clk-mux-zynqmp.c')
| -rw-r--r-- | drivers/clk/zynqmp/clk-mux-zynqmp.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/drivers/clk/zynqmp/clk-mux-zynqmp.c b/drivers/clk/zynqmp/clk-mux-zynqmp.c new file mode 100644 index 000000000..9b5d3050b --- /dev/null +++ b/drivers/clk/zynqmp/clk-mux-zynqmp.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Zynq UltraScale+ MPSoC mux + * + * Copyright (C) 2016-2018 Xilinx + */ + +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include "clk-zynqmp.h" + +/* + * DOC: basic adjustable multiplexer clock that cannot gate + * + * Traits of this clock: + * prepare - clk_prepare only ensures that parents are prepared + * enable - clk_enable only ensures that parents are enabled + * rate - rate is only affected by parent switching. No clk_set_rate support + * parent - parent is adjustable through clk_set_parent + */ + +/** + * struct zynqmp_clk_mux - multiplexer clock + * + * @hw: handle between common and hardware-specific interfaces + * @flags: hardware-specific flags + * @clk_id: Id of clock + */ +struct zynqmp_clk_mux { + struct clk_hw hw; + u8 flags; + u32 clk_id; +}; + +#define to_zynqmp_clk_mux(_hw) container_of(_hw, struct zynqmp_clk_mux, hw) + +/** + * zynqmp_clk_mux_get_parent() - Get parent of clock + * @hw: handle between common and hardware-specific interfaces + * + * Return: Parent index on success or number of parents in case of error + */ +static u8 zynqmp_clk_mux_get_parent(struct clk_hw *hw) +{ + struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw); + const char *clk_name = clk_hw_get_name(hw); + u32 clk_id = mux->clk_id; + u32 val; + int ret; + + ret = zynqmp_pm_clock_getparent(clk_id, &val); + + if (ret) { + pr_debug("%s() getparent failed for clock: %s, ret = %d\n", + __func__, clk_name, ret); + /* + * clk_core_get_parent_by_index() takes num_parents as incorrect + * index which is exactly what I want to return here + */ + return clk_hw_get_num_parents(hw); + } + + return val; +} + +/** + * zynqmp_clk_mux_set_parent() - Set parent of clock + * @hw: handle between common and hardware-specific interfaces + * @index: Parent index + * + * Return: 0 on success else error+reason + */ +static int zynqmp_clk_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw); + const char *clk_name = clk_hw_get_name(hw); + u32 clk_id = mux->clk_id; + int ret; + + ret = zynqmp_pm_clock_setparent(clk_id, index); + + if (ret) + pr_debug("%s() set parent failed for clock: %s, ret = %d\n", + __func__, clk_name, ret); + + return ret; +} + +static const struct clk_ops zynqmp_clk_mux_ops = { + .get_parent = zynqmp_clk_mux_get_parent, + .set_parent = zynqmp_clk_mux_set_parent, + .determine_rate = __clk_mux_determine_rate_closest, +}; + +static const struct clk_ops zynqmp_clk_mux_ro_ops = { + .get_parent = zynqmp_clk_mux_get_parent, +}; + +static inline unsigned long zynqmp_clk_map_mux_ccf_flags( + const u32 zynqmp_type_flag) +{ + unsigned long ccf_flag = 0; + + if (zynqmp_type_flag & ZYNQMP_CLK_MUX_INDEX_ONE) + ccf_flag |= CLK_MUX_INDEX_ONE; + if (zynqmp_type_flag & ZYNQMP_CLK_MUX_INDEX_BIT) + ccf_flag |= CLK_MUX_INDEX_BIT; + if (zynqmp_type_flag & ZYNQMP_CLK_MUX_HIWORD_MASK) + ccf_flag |= CLK_MUX_HIWORD_MASK; + if (zynqmp_type_flag & ZYNQMP_CLK_MUX_READ_ONLY) + ccf_flag |= CLK_MUX_READ_ONLY; + if (zynqmp_type_flag & ZYNQMP_CLK_MUX_ROUND_CLOSEST) + ccf_flag |= CLK_MUX_ROUND_CLOSEST; + if (zynqmp_type_flag & ZYNQMP_CLK_MUX_BIG_ENDIAN) + ccf_flag |= CLK_MUX_BIG_ENDIAN; + + return ccf_flag; +} + +/** + * zynqmp_clk_register_mux() - Register a mux table with the clock + * framework + * @name: Name of this clock + * @clk_id: Id of this clock + * @parents: Name of this clock's parents + * @num_parents: Number of parents + * @nodes: Clock topology node + * + * Return: clock hardware of the registered clock mux + */ +struct clk_hw *zynqmp_clk_register_mux(const char *name, u32 clk_id, + const char * const *parents, + u8 num_parents, + const struct clock_topology *nodes) +{ + struct zynqmp_clk_mux *mux; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + return ERR_PTR(-ENOMEM); + + init.name = name; + if (nodes->type_flag & CLK_MUX_READ_ONLY) + init.ops = &zynqmp_clk_mux_ro_ops; + else + init.ops = &zynqmp_clk_mux_ops; + + init.flags = zynqmp_clk_map_common_ccf_flags(nodes->flag); + + init.parent_names = parents; + init.num_parents = num_parents; + mux->flags = zynqmp_clk_map_mux_ccf_flags(nodes->type_flag); + mux->hw.init = &init; + mux->clk_id = clk_id; + + hw = &mux->hw; + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(mux); + hw = ERR_PTR(ret); + } + + return hw; +} |