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Diffstat (limited to 'drivers/clk/bcm/clk-kona.h')
| -rw-r--r-- | drivers/clk/bcm/clk-kona.h | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/drivers/clk/bcm/clk-kona.h b/drivers/clk/bcm/clk-kona.h new file mode 100644 index 0000000..5e139ad --- /dev/null +++ b/drivers/clk/bcm/clk-kona.h @@ -0,0 +1,410 @@ +/* + * Copyright (C) 2013 Broadcom Corporation + * Copyright 2013 Linaro Limited + * + * 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 version 2. + * + * 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. + */ + +#ifndef _CLK_KONA_H +#define _CLK_KONA_H + +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/device.h> +#include <linux/of.h> +#include <linux/clk-provider.h> + +#define BILLION 1000000000 + +/* The common clock framework uses u8 to represent a parent index */ +#define PARENT_COUNT_MAX ((u32)U8_MAX) + +#define BAD_CLK_INDEX U8_MAX /* Can't ever be valid */ +#define BAD_CLK_NAME ((const char *)-1) + +#define BAD_SCALED_DIV_VALUE U64_MAX + +/* + * Utility macros for object flag management. If possible, flags + * should be defined such that 0 is the desired default value. + */ +#define FLAG(type, flag) BCM_CLK_ ## type ## _FLAGS_ ## flag +#define FLAG_SET(obj, type, flag) ((obj)->flags |= FLAG(type, flag)) +#define FLAG_CLEAR(obj, type, flag) ((obj)->flags &= ~(FLAG(type, flag))) +#define FLAG_FLIP(obj, type, flag) ((obj)->flags ^= FLAG(type, flag)) +#define FLAG_TEST(obj, type, flag) (!!((obj)->flags & FLAG(type, flag))) + +/* Clock field state tests */ + +#define gate_exists(gate) FLAG_TEST(gate, GATE, EXISTS) +#define gate_is_enabled(gate) FLAG_TEST(gate, GATE, ENABLED) +#define gate_is_hw_controllable(gate) FLAG_TEST(gate, GATE, HW) +#define gate_is_sw_controllable(gate) FLAG_TEST(gate, GATE, SW) +#define gate_is_sw_managed(gate) FLAG_TEST(gate, GATE, SW_MANAGED) +#define gate_is_no_disable(gate) FLAG_TEST(gate, GATE, NO_DISABLE) + +#define gate_flip_enabled(gate) FLAG_FLIP(gate, GATE, ENABLED) + +#define divider_exists(div) FLAG_TEST(div, DIV, EXISTS) +#define divider_is_fixed(div) FLAG_TEST(div, DIV, FIXED) +#define divider_has_fraction(div) (!divider_is_fixed(div) && \ + (div)->frac_width > 0) + +#define selector_exists(sel) ((sel)->width != 0) +#define trigger_exists(trig) FLAG_TEST(trig, TRIG, EXISTS) + +/* Clock type, used to tell common block what it's part of */ +enum bcm_clk_type { + bcm_clk_none, /* undefined clock type */ + bcm_clk_bus, + bcm_clk_core, + bcm_clk_peri +}; + +/* + * Each CCU defines a mapped area of memory containing registers + * used to manage clocks implemented by the CCU. Access to memory + * within the CCU's space is serialized by a spinlock. Before any + * (other) address can be written, a special access "password" value + * must be written to its WR_ACCESS register (located at the base + * address of the range). We keep track of the name of each CCU as + * it is set up, and maintain them in a list. + */ +struct ccu_data { + void __iomem *base; /* base of mapped address space */ + spinlock_t lock; /* serialization lock */ + bool write_enabled; /* write access is currently enabled */ + struct list_head links; /* for ccu_list */ + struct device_node *node; + struct clk_onecell_data data; + const char *name; + u32 range; /* byte range of address space */ +}; + +/* + * Gating control and status is managed by a 32-bit gate register. + * + * There are several types of gating available: + * - (no gate) + * A clock with no gate is assumed to be always enabled. + * - hardware-only gating (auto-gating) + * Enabling or disabling clocks with this type of gate is + * managed automatically by the hardware. Such clocks can be + * considered by the software to be enabled. The current status + * of auto-gated clocks can be read from the gate status bit. + * - software-only gating + * Auto-gating is not available for this type of clock. + * Instead, software manages whether it's enabled by setting or + * clearing the enable bit. The current gate status of a gate + * under software control can be read from the gate status bit. + * To ensure a change to the gating status is complete, the + * status bit can be polled to verify that the gate has entered + * the desired state. + * - selectable hardware or software gating + * Gating for this type of clock can be configured to be either + * under software or hardware control. Which type is in use is + * determined by the hw_sw_sel bit of the gate register. + */ +struct bcm_clk_gate { + u32 offset; /* gate register offset */ + u32 status_bit; /* 0: gate is disabled; 0: gatge is enabled */ + u32 en_bit; /* 0: disable; 1: enable */ + u32 hw_sw_sel_bit; /* 0: hardware gating; 1: software gating */ + u32 flags; /* BCM_CLK_GATE_FLAGS_* below */ +}; + +/* + * Gate flags: + * HW means this gate can be auto-gated + * SW means the state of this gate can be software controlled + * NO_DISABLE means this gate is (only) enabled if under software control + * SW_MANAGED means the status of this gate is under software control + * ENABLED means this software-managed gate is *supposed* to be enabled + */ +#define BCM_CLK_GATE_FLAGS_EXISTS ((u32)1 << 0) /* Gate is valid */ +#define BCM_CLK_GATE_FLAGS_HW ((u32)1 << 1) /* Can auto-gate */ +#define BCM_CLK_GATE_FLAGS_SW ((u32)1 << 2) /* Software control */ +#define BCM_CLK_GATE_FLAGS_NO_DISABLE ((u32)1 << 3) /* HW or enabled */ +#define BCM_CLK_GATE_FLAGS_SW_MANAGED ((u32)1 << 4) /* SW now in control */ +#define BCM_CLK_GATE_FLAGS_ENABLED ((u32)1 << 5) /* If SW_MANAGED */ + +/* + * Gate initialization macros. + * + * Any gate initially under software control will be enabled. + */ + +/* A hardware/software gate initially under software control */ +#define HW_SW_GATE(_offset, _status_bit, _en_bit, _hw_sw_sel_bit) \ + { \ + .offset = (_offset), \ + .status_bit = (_status_bit), \ + .en_bit = (_en_bit), \ + .hw_sw_sel_bit = (_hw_sw_sel_bit), \ + .flags = FLAG(GATE, HW)|FLAG(GATE, SW)| \ + FLAG(GATE, SW_MANAGED)|FLAG(GATE, ENABLED)| \ + FLAG(GATE, EXISTS), \ + } + +/* A hardware/software gate initially under hardware control */ +#define HW_SW_GATE_AUTO(_offset, _status_bit, _en_bit, _hw_sw_sel_bit) \ + { \ + .offset = (_offset), \ + .status_bit = (_status_bit), \ + .en_bit = (_en_bit), \ + .hw_sw_sel_bit = (_hw_sw_sel_bit), \ + .flags = FLAG(GATE, HW)|FLAG(GATE, SW)| \ + FLAG(GATE, EXISTS), \ + } + +/* A hardware-or-enabled gate (enabled if not under hardware control) */ +#define HW_ENABLE_GATE(_offset, _status_bit, _en_bit, _hw_sw_sel_bit) \ + { \ + .offset = (_offset), \ + .status_bit = (_status_bit), \ + .en_bit = (_en_bit), \ + .hw_sw_sel_bit = (_hw_sw_sel_bit), \ + .flags = FLAG(GATE, HW)|FLAG(GATE, SW)| \ + FLAG(GATE, NO_DISABLE)|FLAG(GATE, EXISTS), \ + } + +/* A software-only gate */ +#define SW_ONLY_GATE(_offset, _status_bit, _en_bit) \ + { \ + .offset = (_offset), \ + .status_bit = (_status_bit), \ + .en_bit = (_en_bit), \ + .flags = FLAG(GATE, SW)|FLAG(GATE, SW_MANAGED)| \ + FLAG(GATE, ENABLED)|FLAG(GATE, EXISTS), \ + } + +/* A hardware-only gate */ +#define HW_ONLY_GATE(_offset, _status_bit) \ + { \ + .offset = (_offset), \ + .status_bit = (_status_bit), \ + .flags = FLAG(GATE, HW)|FLAG(GATE, EXISTS), \ + } + +/* + * Each clock can have zero, one, or two dividers which change the + * output rate of the clock. Each divider can be either fixed or + * variable. If there are two dividers, they are the "pre-divider" + * and the "regular" or "downstream" divider. If there is only one, + * there is no pre-divider. + * + * A fixed divider is any non-zero (positive) value, and it + * indicates how the input rate is affected by the divider. + * + * The value of a variable divider is maintained in a sub-field of a + * 32-bit divider register. The position of the field in the + * register is defined by its offset and width. The value recorded + * in this field is always 1 less than the value it represents. + * + * In addition, a variable divider can indicate that some subset + * of its bits represent a "fractional" part of the divider. Such + * bits comprise the low-order portion of the divider field, and can + * be viewed as representing the portion of the divider that lies to + * the right of the decimal point. Most variable dividers have zero + * fractional bits. Variable dividers with non-zero fraction width + * still record a value 1 less than the value they represent; the + * added 1 does *not* affect the low-order bit in this case, it + * affects the bits above the fractional part only. (Often in this + * code a divider field value is distinguished from the value it + * represents by referring to the latter as a "divisor".) + * + * In order to avoid dealing with fractions, divider arithmetic is + * performed using "scaled" values. A scaled value is one that's + * been left-shifted by the fractional width of a divider. Dividing + * a scaled value by a scaled divisor produces the desired quotient + * without loss of precision and without any other special handling + * for fractions. + * + * The recorded value of a variable divider can be modified. To + * modify either divider (or both), a clock must be enabled (i.e., + * using its gate). In addition, a trigger register (described + * below) must be used to commit the change, and polled to verify + * the change is complete. + */ +struct bcm_clk_div { + union { + struct { /* variable divider */ + u32 offset; /* divider register offset */ + u32 shift; /* field shift */ + u32 width; /* field width */ + u32 frac_width; /* field fraction width */ + + u64 scaled_div; /* scaled divider value */ + }; + u32 fixed; /* non-zero fixed divider value */ + }; + u32 flags; /* BCM_CLK_DIV_FLAGS_* below */ +}; + +/* + * Divider flags: + * EXISTS means this divider exists + * FIXED means it is a fixed-rate divider + */ +#define BCM_CLK_DIV_FLAGS_EXISTS ((u32)1 << 0) /* Divider is valid */ +#define BCM_CLK_DIV_FLAGS_FIXED ((u32)1 << 1) /* Fixed-value */ + +/* Divider initialization macros */ + +/* A fixed (non-zero) divider */ +#define FIXED_DIVIDER(_value) \ + { \ + .fixed = (_value), \ + .flags = FLAG(DIV, EXISTS)|FLAG(DIV, FIXED), \ + } + +/* A divider with an integral divisor */ +#define DIVIDER(_offset, _shift, _width) \ + { \ + .offset = (_offset), \ + .shift = (_shift), \ + .width = (_width), \ + .scaled_div = BAD_SCALED_DIV_VALUE, \ + .flags = FLAG(DIV, EXISTS), \ + } + +/* A divider whose divisor has an integer and fractional part */ +#define FRAC_DIVIDER(_offset, _shift, _width, _frac_width) \ + { \ + .offset = (_offset), \ + .shift = (_shift), \ + .width = (_width), \ + .frac_width = (_frac_width), \ + .scaled_div = BAD_SCALED_DIV_VALUE, \ + .flags = FLAG(DIV, EXISTS), \ + } + +/* + * Clocks may have multiple "parent" clocks. If there is more than + * one, a selector must be specified to define which of the parent + * clocks is currently in use. The selected clock is indicated in a + * sub-field of a 32-bit selector register. The range of + * representable selector values typically exceeds the number of + * available parent clocks. Occasionally the reset value of a + * selector field is explicitly set to a (specific) value that does + * not correspond to a defined input clock. + * + * We register all known parent clocks with the common clock code + * using a packed array (i.e., no empty slots) of (parent) clock + * names, and refer to them later using indexes into that array. + * We maintain an array of selector values indexed by common clock + * index values in order to map between these common clock indexes + * and the selector values used by the hardware. + * + * Like dividers, a selector can be modified, but to do so a clock + * must be enabled, and a trigger must be used to commit the change. + */ +struct bcm_clk_sel { + u32 offset; /* selector register offset */ + u32 shift; /* field shift */ + u32 width; /* field width */ + + u32 parent_count; /* number of entries in parent_sel[] */ + u32 *parent_sel; /* array of parent selector values */ + u8 clk_index; /* current selected index in parent_sel[] */ +}; + +/* Selector initialization macro */ +#define SELECTOR(_offset, _shift, _width) \ + { \ + .offset = (_offset), \ + .shift = (_shift), \ + .width = (_width), \ + .clk_index = BAD_CLK_INDEX, \ + } + +/* + * Making changes to a variable divider or a selector for a clock + * requires the use of a trigger. A trigger is defined by a single + * bit within a register. To signal a change, a 1 is written into + * that bit. To determine when the change has been completed, that + * trigger bit is polled; the read value will be 1 while the change + * is in progress, and 0 when it is complete. + * + * Occasionally a clock will have more than one trigger. In this + * case, the "pre-trigger" will be used when changing a clock's + * selector and/or its pre-divider. + */ +struct bcm_clk_trig { + u32 offset; /* trigger register offset */ + u32 bit; /* trigger bit */ + u32 flags; /* BCM_CLK_TRIG_FLAGS_* below */ +}; + +/* + * Trigger flags: + * EXISTS means this trigger exists + */ +#define BCM_CLK_TRIG_FLAGS_EXISTS ((u32)1 << 0) /* Trigger is valid */ + +/* Trigger initialization macro */ +#define TRIGGER(_offset, _bit) \ + { \ + .offset = (_offset), \ + .bit = (_bit), \ + .flags = FLAG(TRIG, EXISTS), \ + } + +struct peri_clk_data { + struct bcm_clk_gate gate; + struct bcm_clk_trig pre_trig; + struct bcm_clk_div pre_div; + struct bcm_clk_trig trig; + struct bcm_clk_div div; + struct bcm_clk_sel sel; + const char *clocks[]; /* must be last; use CLOCKS() to declare */ +}; +#define CLOCKS(...) { __VA_ARGS__, NULL, } +#define NO_CLOCKS { NULL, } /* Must use of no parent clocks */ + +struct kona_clk { + struct clk_hw hw; + struct clk_init_data init_data; + const char *name; /* name of this clock */ + struct ccu_data *ccu; /* ccu this clock is associated with */ + enum bcm_clk_type type; + union { + void *data; + struct peri_clk_data *peri; + }; +}; +#define to_kona_clk(_hw) \ + container_of(_hw, struct kona_clk, hw) + +/* Exported globals */ + +extern struct clk_ops kona_peri_clk_ops; + +/* Help functions */ + +#define PERI_CLK_SETUP(clks, ccu, id, name) \ + clks[id] = kona_clk_setup(ccu, #name, bcm_clk_peri, &name ## _data) + +/* Externally visible functions */ + +extern u64 do_div_round_closest(u64 dividend, unsigned long divisor); +extern u64 scaled_div_max(struct bcm_clk_div *div); +extern u64 scaled_div_build(struct bcm_clk_div *div, u32 div_value, + u32 billionths); + +extern struct clk *kona_clk_setup(struct ccu_data *ccu, const char *name, + enum bcm_clk_type type, void *data); +extern void __init kona_dt_ccu_setup(struct device_node *node, + int (*ccu_clks_setup)(struct ccu_data *)); +extern bool __init kona_ccu_init(struct ccu_data *ccu); + +#endif /* _CLK_KONA_H */ |
