/*
* 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)))
/* CCU field state tests */
#define ccu_policy_exists(ccu_policy) ((ccu_policy)->enable.offset != 0)
/* Clock field state tests */
#define policy_exists(policy) ((policy)->offset != 0)
#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 hyst_exists(hyst) ((hyst)->offset != 0)
#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)->u.s.frac_width > 0)
#define selector_exists(sel) ((sel)->width != 0)
#define trigger_exists(trig) FLAG_TEST(trig, TRIG, EXISTS)
#define policy_lvm_en_exists(enable) ((enable)->offset != 0)
#define policy_ctl_exists(control) ((control)->offset != 0)
/* 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
};
/*
* CCU policy control for clocks. Clocks can be enabled or disabled
* based on the CCU policy in effect. One bit in each policy mask
* register (one per CCU policy) represents whether the clock is
* enabled when that policy is effect or not. The CCU policy engine
* must be stopped to update these bits, and must be restarted again
* afterward.
*/
struct bcm_clk_policy {
u32 offset; /* first policy mask register offset */
u32 bit; /* bit used in all mask registers */
};
/* Policy initialization macro */
#define POLICY(_offset, _bit) \
{ \
.offset = (_offset), \
.bit = (_bit), \
}
/*
* 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), \
}
/* Gate hysteresis for clocks */
struct bcm_clk_hyst {
u32 offset; /* hyst register offset (normally CLKGATE) */
u32 en_bit; /* bit used to enable hysteresis */
u32 val_bit; /* if enabled: 0 = low delay; 1 = high delay */
};
/* Hysteresis initialization macro */
#define HYST(_offset, _en_bit, _val_bit) \
{ \
.offset = (_offset), \
.en_bit = (_en_bit), \
.val_bit = (_val_bit), \
}
/*
* 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 */
} s;
u32 fixed; /* non-zero fixed divider value */
} u;
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) \
{ \
.u.fixed = (_value), \
.flags = FLAG(DIV, EXISTS)|FLAG(DIV, FIXED), \
}
/* A divider with an integral divisor */
#define DIVIDER(_offset, _shift, _width) \
{ \
.u.s.offset = (_offset), \
.u.s.shift = (_shift), \
.u.s.width = (_width), \
.u.s.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) \
{ \
.u.s.offset = (_offset), \
.u.s.shift = (_shift), \
.u.s.width = (_width), \
.u.s.frac_width = (_frac_width), \
.u.s.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_policy policy;
struct bcm_clk_gate gate;
struct bcm_clk_hyst hyst;
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; /* includes 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;
} u;
};
#define to_kona_clk(_hw) \
container_of(_hw, struct kona_clk, hw)
/* Initialization macro for an entry in a CCU's kona_clks[] array. */
#define KONA_CLK(_ccu_name, _clk_name, _type) \
{ \
.init_data = { \
.name = #_clk_name, \
.ops = &kona_ ## _type ## _clk_ops, \
}, \
.ccu = &_ccu_name ## _ccu_data, \
.type = bcm_clk_ ## _type, \
.u.data = &_clk_name ## _data, \
}
#define LAST_KONA_CLK { .type = bcm_clk_none }
/*
* CCU policy control. To enable software update of the policy
* tables the CCU policy engine must be stopped by setting the
* software update enable bit (LVM_EN). After an update the engine
* is restarted using the GO bit and either the GO_ATL or GO_AC bit.
*/
struct bcm_lvm_en {
u32 offset; /* LVM_EN register offset */
u32 bit; /* POLICY_CONFIG_EN bit in register */
};
/* Policy enable initialization macro */
#define CCU_LVM_EN(_offset, _bit) \
{ \
.offset = (_offset), \
.bit = (_bit), \
}
struct bcm_policy_ctl {
u32 offset; /* POLICY_CTL register offset */
u32 go_bit;
u32 atl_bit; /* GO, GO_ATL, and GO_AC bits */
u32 ac_bit;
};
/* Policy control initialization macro */
#define CCU_POLICY_CTL(_offset, _go_bit, _ac_bit, _atl_bit) \
{ \
.offset = (_offset), \
.go_bit = (_go_bit), \
.ac_bit = (_ac_bit), \
.atl_bit = (_atl_bit), \
}
struct ccu_policy {
struct bcm_lvm_en enable;
struct bcm_policy_ctl control;
};
/*
* 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 ccu_policy policy;
struct list_head links; /* for ccu_list */
struct device_node *node;
struct clk_onecell_data clk_data;
const char *name;
u32 range; /* byte range of address space */
struct kona_clk kona_clks[]; /* must be last */
};
/* Initialization for common fields in a Kona ccu_data structure */
#define KONA_CCU_COMMON(_prefix, _name, _ccuname) \
.name = #_name "_ccu", \
.lock = __SPIN_LOCK_UNLOCKED(_name ## _ccu_data.lock), \
.links = LIST_HEAD_INIT(_name ## _ccu_data.links), \
.clk_data = { \
.clk_num = _prefix ## _ ## _ccuname ## _CCU_CLOCK_COUNT, \
}
/* Exported globals */
extern struct clk_ops kona_peri_clk_ops;
/* Externally visible functions */
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 kona_clk *bcm_clk);
extern void __init kona_dt_ccu_setup(struct ccu_data *ccu,
struct device_node *node);
extern bool __init kona_ccu_init(struct ccu_data *ccu);
#endif /* _CLK_KONA_H */