diff options
Diffstat (limited to 'drivers/clk/ti/mux.c')
| -rw-r--r-- | drivers/clk/ti/mux.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c new file mode 100644 index 000000000..4205ff4ba --- /dev/null +++ b/drivers/clk/ti/mux.c @@ -0,0 +1,295 @@ +/* + * TI Multiplexer Clock + * + * Copyright (C) 2013 Texas Instruments, Inc. + * + * Tero Kristo <t-kristo@ti.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; 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/slab.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/clk/ti.h> +#include "clock.h" + +#undef pr_fmt +#define pr_fmt(fmt) "%s: " fmt, __func__ + +static u8 ti_clk_mux_get_parent(struct clk_hw *hw) +{ + struct clk_omap_mux *mux = to_clk_omap_mux(hw); + int num_parents = clk_hw_get_num_parents(hw); + u32 val; + + /* + * FIXME need a mux-specific flag to determine if val is bitwise or + * numeric. e.g. sys_clkin_ck's clksel field is 3 bits wide, but ranges + * from 0x1 to 0x7 (index starts at one) + * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so + * val = 0x4 really means "bit 2, index starts at bit 0" + */ + val = ti_clk_ll_ops->clk_readl(&mux->reg) >> mux->shift; + val &= mux->mask; + + if (mux->table) { + int i; + + for (i = 0; i < num_parents; i++) + if (mux->table[i] == val) + return i; + return -EINVAL; + } + + if (val && (mux->flags & CLK_MUX_INDEX_BIT)) + val = ffs(val) - 1; + + if (val && (mux->flags & CLK_MUX_INDEX_ONE)) + val--; + + if (val >= num_parents) + return -EINVAL; + + return val; +} + +static int ti_clk_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_omap_mux *mux = to_clk_omap_mux(hw); + u32 val; + + if (mux->table) { + index = mux->table[index]; + } else { + if (mux->flags & CLK_MUX_INDEX_BIT) + index = (1 << ffs(index)); + + if (mux->flags & CLK_MUX_INDEX_ONE) + index++; + } + + if (mux->flags & CLK_MUX_HIWORD_MASK) { + val = mux->mask << (mux->shift + 16); + } else { + val = ti_clk_ll_ops->clk_readl(&mux->reg); + val &= ~(mux->mask << mux->shift); + } + val |= index << mux->shift; + ti_clk_ll_ops->clk_writel(val, &mux->reg); + ti_clk_latch(&mux->reg, mux->latch); + + return 0; +} + +/** + * clk_mux_save_context - Save the parent selcted in the mux + * @hw: pointer struct clk_hw + * + * Save the parent mux value. + */ +static int clk_mux_save_context(struct clk_hw *hw) +{ + struct clk_omap_mux *mux = to_clk_omap_mux(hw); + + mux->saved_parent = ti_clk_mux_get_parent(hw); + return 0; +} + +/** + * clk_mux_restore_context - Restore the parent in the mux + * @hw: pointer struct clk_hw + * + * Restore the saved parent mux value. + */ +static void clk_mux_restore_context(struct clk_hw *hw) +{ + struct clk_omap_mux *mux = to_clk_omap_mux(hw); + + ti_clk_mux_set_parent(hw, mux->saved_parent); +} + +const struct clk_ops ti_clk_mux_ops = { + .get_parent = ti_clk_mux_get_parent, + .set_parent = ti_clk_mux_set_parent, + .determine_rate = __clk_mux_determine_rate, + .save_context = clk_mux_save_context, + .restore_context = clk_mux_restore_context, +}; + +static struct clk *_register_mux(struct device_node *node, const char *name, + const char * const *parent_names, + u8 num_parents, unsigned long flags, + struct clk_omap_reg *reg, u8 shift, u32 mask, + s8 latch, u8 clk_mux_flags, u32 *table) +{ + struct clk_omap_mux *mux; + struct clk *clk; + struct clk_init_data init; + + /* allocate the mux */ + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &ti_clk_mux_ops; + init.flags = flags; + init.parent_names = parent_names; + init.num_parents = num_parents; + + /* struct clk_mux assignments */ + memcpy(&mux->reg, reg, sizeof(*reg)); + mux->shift = shift; + mux->mask = mask; + mux->latch = latch; + mux->flags = clk_mux_flags; + mux->table = table; + mux->hw.init = &init; + + clk = of_ti_clk_register(node, &mux->hw, name); + + if (IS_ERR(clk)) + kfree(mux); + + return clk; +} + +/** + * of_mux_clk_setup - Setup function for simple mux rate clock + * @node: DT node for the clock + * + * Sets up a basic clock multiplexer. + */ +static void of_mux_clk_setup(struct device_node *node) +{ + struct clk *clk; + struct clk_omap_reg reg; + unsigned int num_parents; + const char **parent_names; + const char *name; + u8 clk_mux_flags = 0; + u32 mask = 0; + u32 shift = 0; + s32 latch = -EINVAL; + u32 flags = CLK_SET_RATE_NO_REPARENT; + + num_parents = of_clk_get_parent_count(node); + if (num_parents < 2) { + pr_err("mux-clock %pOFn must have parents\n", node); + return; + } + parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL); + if (!parent_names) + goto cleanup; + + of_clk_parent_fill(node, parent_names, num_parents); + + if (ti_clk_get_reg_addr(node, 0, ®)) + goto cleanup; + + of_property_read_u32(node, "ti,bit-shift", &shift); + + of_property_read_u32(node, "ti,latch-bit", &latch); + + if (of_property_read_bool(node, "ti,index-starts-at-one")) + clk_mux_flags |= CLK_MUX_INDEX_ONE; + + if (of_property_read_bool(node, "ti,set-rate-parent")) + flags |= CLK_SET_RATE_PARENT; + + /* Generate bit-mask based on parent info */ + mask = num_parents; + if (!(clk_mux_flags & CLK_MUX_INDEX_ONE)) + mask--; + + mask = (1 << fls(mask)) - 1; + + name = ti_dt_clk_name(node); + clk = _register_mux(node, name, parent_names, num_parents, + flags, ®, shift, mask, latch, clk_mux_flags, + NULL); + + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); + +cleanup: + kfree(parent_names); +} +CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup); + +struct clk_hw *ti_clk_build_component_mux(struct ti_clk_mux *setup) +{ + struct clk_omap_mux *mux; + int num_parents; + + if (!setup) + return NULL; + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + return ERR_PTR(-ENOMEM); + + mux->shift = setup->bit_shift; + mux->latch = -EINVAL; + + mux->reg.index = setup->module; + mux->reg.offset = setup->reg; + + if (setup->flags & CLKF_INDEX_STARTS_AT_ONE) + mux->flags |= CLK_MUX_INDEX_ONE; + + num_parents = setup->num_parents; + + mux->mask = num_parents - 1; + mux->mask = (1 << fls(mux->mask)) - 1; + + return &mux->hw; +} + +static void __init of_ti_composite_mux_clk_setup(struct device_node *node) +{ + struct clk_omap_mux *mux; + unsigned int num_parents; + u32 val; + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + return; + + if (ti_clk_get_reg_addr(node, 0, &mux->reg)) + goto cleanup; + + if (!of_property_read_u32(node, "ti,bit-shift", &val)) + mux->shift = val; + + if (of_property_read_bool(node, "ti,index-starts-at-one")) + mux->flags |= CLK_MUX_INDEX_ONE; + + num_parents = of_clk_get_parent_count(node); + + if (num_parents < 2) { + pr_err("%pOFn must have parents\n", node); + goto cleanup; + } + + mux->mask = num_parents - 1; + mux->mask = (1 << fls(mux->mask)) - 1; + + if (!ti_clk_add_component(node, &mux->hw, CLK_COMPONENT_TYPE_MUX)) + return; + +cleanup: + kfree(mux); +} +CLK_OF_DECLARE(ti_composite_mux_clk_setup, "ti,composite-mux-clock", + of_ti_composite_mux_clk_setup); |