diff options
| -rw-r--r-- | Documentation/devicetree/bindings/clock/ti/mux.txt | 76 | ||||
| -rw-r--r-- | drivers/clk/ti/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clk/ti/composite.c | 2 | ||||
| -rw-r--r-- | drivers/clk/ti/mux.c | 246 | ||||
| -rw-r--r-- | include/linux/clk/ti.h | 1 |
5 files changed, 325 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/clock/ti/mux.txt b/Documentation/devicetree/bindings/clock/ti/mux.txt new file mode 100644 index 00000000000..2d0d170f800 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/ti/mux.txt @@ -0,0 +1,76 @@ +Binding for TI mux clock. + +Binding status: Unstable - ABI compatibility may be broken in the future + +This binding uses the common clock binding[1]. It assumes a +register-mapped multiplexer with multiple input clock signals or +parents, one of which can be selected as output. This clock does not +gate or adjust the parent rate via a divider or multiplier. + +By default the "clocks" property lists the parents in the same order +as they are programmed into the regster. E.g: + + clocks = <&foo_clock>, <&bar_clock>, <&baz_clock>; + +results in programming the register as follows: + +register value selected parent clock +0 foo_clock +1 bar_clock +2 baz_clock + +Some clock controller IPs do not allow a value of zero to be programmed +into the register, instead indexing begins at 1. The optional property +"index-starts-at-one" modified the scheme as follows: + +register value selected clock parent +1 foo_clock +2 bar_clock +3 baz_clock + +The binding must provide the register to control the mux. Optionally +the number of bits to shift the control field in the register can be +supplied. If the shift value is missing it is the same as supplying +a zero shift. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible : shall be "ti,mux-clock" or "ti,composite-mux-clock". +- #clock-cells : from common clock binding; shall be set to 0. +- clocks : link phandles of parent clocks +- reg : register offset for register controlling adjustable mux + +Optional properties: +- ti,bit-shift : number of bits to shift the bit-mask, defaults to + 0 if not present +- ti,index-starts-at-one : valid input select programming starts at 1, not + zero +- ti,set-rate-parent : clk_set_rate is propagated to parent clock, + not supported by the composite-mux-clock subtype + +Examples: + +sys_clkin_ck: sys_clkin_ck@4a306110 { + #clock-cells = <0>; + compatible = "ti,mux-clock"; + clocks = <&virt_12000000_ck>, <&virt_13000000_ck>, <&virt_16800000_ck>, <&virt_19200000_ck>, <&virt_26000000_ck>, <&virt_27000000_ck>, <&virt_38400000_ck>; + reg = <0x0110>; + ti,index-starts-at-one; +}; + +abe_dpll_bypass_clk_mux_ck: abe_dpll_bypass_clk_mux_ck@4a306108 { + #clock-cells = <0>; + compatible = "ti,mux-clock"; + clocks = <&sys_clkin_ck>, <&sys_32k_ck>; + ti,bit-shift = <24>; + reg = <0x0108>; +}; + +mcbsp5_mux_fck: mcbsp5_mux_fck { + #clock-cells = <0>; + compatible = "ti,composite-mux-clock"; + clocks = <&core_96m_fck>, <&mcbsp_clks>; + ti,bit-shift = <4>; + reg = <0x02d8>; +}; diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile index ae7cd1e91cd..d98a47fb13a 100644 --- a/drivers/clk/ti/Makefile +++ b/drivers/clk/ti/Makefile @@ -1,5 +1,5 @@ ifneq ($(CONFIG_OF),) obj-y += clk.o autoidle.o clockdomain.o clk-common = dpll.o composite.o divider.o gate.o \ - fixed-factor.o + fixed-factor.o mux.o endif diff --git a/drivers/clk/ti/composite.c b/drivers/clk/ti/composite.c index ffb8db4829b..19d8980ba45 100644 --- a/drivers/clk/ti/composite.c +++ b/drivers/clk/ti/composite.c @@ -173,7 +173,7 @@ static void __init ti_clk_register_composite(struct clk_hw *hw, clk = clk_register_composite(NULL, node->name, parent_names, num_parents, _get_hw(cclk, CLK_COMPONENT_TYPE_MUX), - &clk_mux_ops, + &ti_clk_mux_ops, _get_hw(cclk, CLK_COMPONENT_TYPE_DIVIDER), &ti_composite_divider_ops, _get_hw(cclk, CLK_COMPONENT_TYPE_GATE), diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c new file mode 100644 index 00000000000..0197a478720 --- /dev/null +++ b/drivers/clk/ti/mux.c @@ -0,0 +1,246 @@ +/* + * 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> + +#undef pr_fmt +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw) + +static u8 ti_clk_mux_get_parent(struct clk_hw *hw) +{ + struct clk_mux *mux = to_clk_mux(hw); + int num_parents = __clk_get_num_parents(hw->clk); + 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_mux *mux = to_clk_mux(hw); + u32 val; + unsigned long flags = 0; + + 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->lock) + spin_lock_irqsave(mux->lock, flags); + + 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); + + if (mux->lock) + spin_unlock_irqrestore(mux->lock, flags); + + return 0; +} + +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, +}; + +static struct clk *_register_mux(struct device *dev, const char *name, + const char **parent_names, u8 num_parents, + unsigned long flags, void __iomem *reg, + u8 shift, u32 mask, u8 clk_mux_flags, + u32 *table, spinlock_t *lock) +{ + struct clk_mux *mux; + struct clk *clk; + struct clk_init_data init; + + /* allocate the mux */ + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) { + pr_err("%s: could not allocate mux clk\n", __func__); + return ERR_PTR(-ENOMEM); + } + + init.name = name; + init.ops = &ti_clk_mux_ops; + init.flags = flags | CLK_IS_BASIC; + init.parent_names = parent_names; + init.num_parents = num_parents; + + /* struct clk_mux assignments */ + mux->reg = reg; + mux->shift = shift; + mux->mask = mask; + mux->flags = clk_mux_flags; + mux->lock = lock; + mux->table = table; + mux->hw.init = &init; + + clk = clk_register(dev, &mux->hw); + + 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; + void __iomem *reg; + int num_parents; + const char **parent_names; + int i; + u8 clk_mux_flags = 0; + u32 mask = 0; + u32 shift = 0; + u32 flags = 0; + + num_parents = of_clk_get_parent_count(node); + if (num_parents < 2) { + pr_err("mux-clock %s must have parents\n", node->name); + return; + } + parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL); + if (!parent_names) + goto cleanup; + + for (i = 0; i < num_parents; i++) + parent_names[i] = of_clk_get_parent_name(node, i); + + reg = ti_clk_get_reg_addr(node, 0); + + if (!reg) + goto cleanup; + + of_property_read_u32(node, "ti,bit-shift", &shift); + + 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; + + clk = _register_mux(NULL, node->name, parent_names, num_parents, flags, + reg, shift, mask, clk_mux_flags, NULL, 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); + +static void __init of_ti_composite_mux_clk_setup(struct device_node *node) +{ + struct clk_mux *mux; + int num_parents; + u32 val; + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + return; + + mux->reg = ti_clk_get_reg_addr(node, 0); + + if (!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("%s must have parents\n", node->name); + 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); diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h index a3f89a60de0..6e205b14007 100644 --- a/include/linux/clk/ti.h +++ b/include/linux/clk/ti.h @@ -224,6 +224,7 @@ struct ti_clk_ll_ops { extern struct ti_clk_ll_ops *ti_clk_ll_ops; extern const struct clk_ops ti_clk_divider_ops; +extern const struct clk_ops ti_clk_mux_ops; #define to_clk_hw_omap(_hw) container_of(_hw, struct clk_hw_omap, hw) |