linux_dsm_epyc7002/drivers/clk/ti/divider.c

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/*
* TI Divider 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__
#define div_mask(d) ((1 << ((d)->width)) - 1)
static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
{
unsigned int maxdiv = 0;
const struct clk_div_table *clkt;
for (clkt = table; clkt->div; clkt++)
if (clkt->div > maxdiv)
maxdiv = clkt->div;
return maxdiv;
}
static unsigned int _get_maxdiv(struct clk_divider *divider)
{
if (divider->flags & CLK_DIVIDER_ONE_BASED)
return div_mask(divider);
if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
return 1 << div_mask(divider);
if (divider->table)
return _get_table_maxdiv(divider->table);
return div_mask(divider) + 1;
}
static unsigned int _get_table_div(const struct clk_div_table *table,
unsigned int val)
{
const struct clk_div_table *clkt;
for (clkt = table; clkt->div; clkt++)
if (clkt->val == val)
return clkt->div;
return 0;
}
static unsigned int _get_div(struct clk_divider *divider, unsigned int val)
{
if (divider->flags & CLK_DIVIDER_ONE_BASED)
return val;
if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
return 1 << val;
if (divider->table)
return _get_table_div(divider->table, val);
return val + 1;
}
static unsigned int _get_table_val(const struct clk_div_table *table,
unsigned int div)
{
const struct clk_div_table *clkt;
for (clkt = table; clkt->div; clkt++)
if (clkt->div == div)
return clkt->val;
return 0;
}
static unsigned int _get_val(struct clk_divider *divider, u8 div)
{
if (divider->flags & CLK_DIVIDER_ONE_BASED)
return div;
if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
return __ffs(div);
if (divider->table)
return _get_table_val(divider->table, div);
return div - 1;
}
static unsigned long ti_clk_divider_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
unsigned int div, val;
val = ti_clk_ll_ops->clk_readl(divider->reg) >> divider->shift;
val &= div_mask(divider);
div = _get_div(divider, val);
if (!div) {
WARN(!(divider->flags & CLK_DIVIDER_ALLOW_ZERO),
"%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
clk_hw_get_name(hw));
return parent_rate;
}
return DIV_ROUND_UP(parent_rate, div);
}
/*
* The reverse of DIV_ROUND_UP: The maximum number which
* divided by m is r
*/
#define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1)
static bool _is_valid_table_div(const struct clk_div_table *table,
unsigned int div)
{
const struct clk_div_table *clkt;
for (clkt = table; clkt->div; clkt++)
if (clkt->div == div)
return true;
return false;
}
static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
{
if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
return is_power_of_2(div);
if (divider->table)
return _is_valid_table_div(divider->table, div);
return true;
}
static int ti_clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
unsigned long *best_parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
int i, bestdiv = 0;
unsigned long parent_rate, best = 0, now, maxdiv;
unsigned long parent_rate_saved = *best_parent_rate;
if (!rate)
rate = 1;
maxdiv = _get_maxdiv(divider);
if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
parent_rate = *best_parent_rate;
bestdiv = DIV_ROUND_UP(parent_rate, rate);
bestdiv = bestdiv == 0 ? 1 : bestdiv;
bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
return bestdiv;
}
/*
* The maximum divider we can use without overflowing
* unsigned long in rate * i below
*/
maxdiv = min(ULONG_MAX / rate, maxdiv);
for (i = 1; i <= maxdiv; i++) {
if (!_is_valid_div(divider, i))
continue;
if (rate * i == parent_rate_saved) {
/*
* It's the most ideal case if the requested rate can be
* divided from parent clock without needing to change
* parent rate, so return the divider immediately.
*/
*best_parent_rate = parent_rate_saved;
return i;
}
parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw),
MULT_ROUND_UP(rate, i));
now = DIV_ROUND_UP(parent_rate, i);
if (now <= rate && now > best) {
bestdiv = i;
best = now;
*best_parent_rate = parent_rate;
}
}
if (!bestdiv) {
bestdiv = _get_maxdiv(divider);
*best_parent_rate =
clk_hw_round_rate(clk_hw_get_parent(hw), 1);
}
return bestdiv;
}
static long ti_clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
int div;
div = ti_clk_divider_bestdiv(hw, rate, prate);
return DIV_ROUND_UP(*prate, div);
}
static int ti_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_divider *divider;
unsigned int div, value;
u32 val;
if (!hw || !rate)
return -EINVAL;
divider = to_clk_divider(hw);
div = DIV_ROUND_UP(parent_rate, rate);
value = _get_val(divider, div);
if (value > div_mask(divider))
value = div_mask(divider);
if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
val = div_mask(divider) << (divider->shift + 16);
} else {
val = ti_clk_ll_ops->clk_readl(divider->reg);
val &= ~(div_mask(divider) << divider->shift);
}
val |= value << divider->shift;
ti_clk_ll_ops->clk_writel(val, divider->reg);
return 0;
}
const struct clk_ops ti_clk_divider_ops = {
.recalc_rate = ti_clk_divider_recalc_rate,
.round_rate = ti_clk_divider_round_rate,
.set_rate = ti_clk_divider_set_rate,
};
static struct clk *_register_divider(struct device *dev, const char *name,
const char *parent_name,
unsigned long flags, void __iomem *reg,
u8 shift, u8 width, u8 clk_divider_flags,
const struct clk_div_table *table)
{
struct clk_divider *div;
struct clk *clk;
struct clk_init_data init;
if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) {
if (width + shift > 16) {
pr_warn("divider value exceeds LOWORD field\n");
return ERR_PTR(-EINVAL);
}
}
/* allocate the divider */
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div) {
pr_err("%s: could not allocate divider clk\n", __func__);
return ERR_PTR(-ENOMEM);
}
init.name = name;
init.ops = &ti_clk_divider_ops;
init.flags = flags | CLK_IS_BASIC;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
/* struct clk_divider assignments */
div->reg = reg;
div->shift = shift;
div->width = width;
div->flags = clk_divider_flags;
div->hw.init = &init;
div->table = table;
/* register the clock */
clk = clk_register(dev, &div->hw);
if (IS_ERR(clk))
kfree(div);
return clk;
}
static struct clk_div_table *
_get_div_table_from_setup(struct ti_clk_divider *setup, u8 *width)
{
int valid_div = 0;
struct clk_div_table *table;
int i;
int div;
u32 val;
u8 flags;
if (!setup->num_dividers) {
/* Clk divider table not provided, determine min/max divs */
flags = setup->flags;
if (flags & CLKF_INDEX_STARTS_AT_ONE)
val = 1;
else
val = 0;
div = 1;
while (div < setup->max_div) {
if (flags & CLKF_INDEX_POWER_OF_TWO)
div <<= 1;
else
div++;
val++;
}
*width = fls(val);
return NULL;
}
for (i = 0; i < setup->num_dividers; i++)
if (setup->dividers[i])
valid_div++;
table = kzalloc(sizeof(*table) * (valid_div + 1), GFP_KERNEL);
if (!table)
return ERR_PTR(-ENOMEM);
valid_div = 0;
*width = 0;
for (i = 0; i < setup->num_dividers; i++)
if (setup->dividers[i]) {
table[valid_div].div = setup->dividers[i];
table[valid_div].val = i;
valid_div++;
*width = i;
}
*width = fls(*width);
return table;
}
struct clk_hw *ti_clk_build_component_div(struct ti_clk_divider *setup)
{
struct clk_divider *div;
struct clk_omap_reg *reg;
if (!setup)
return NULL;
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div)
return ERR_PTR(-ENOMEM);
reg = (struct clk_omap_reg *)&div->reg;
reg->index = setup->module;
reg->offset = setup->reg;
if (setup->flags & CLKF_INDEX_STARTS_AT_ONE)
div->flags |= CLK_DIVIDER_ONE_BASED;
if (setup->flags & CLKF_INDEX_POWER_OF_TWO)
div->flags |= CLK_DIVIDER_POWER_OF_TWO;
div->table = _get_div_table_from_setup(setup, &div->width);
div->shift = setup->bit_shift;
return &div->hw;
}
struct clk *ti_clk_register_divider(struct ti_clk *setup)
{
struct ti_clk_divider *div;
struct clk_omap_reg *reg_setup;
u32 reg;
u8 width;
u32 flags = 0;
u8 div_flags = 0;
struct clk_div_table *table;
struct clk *clk;
div = setup->data;
reg_setup = (struct clk_omap_reg *)&reg;
reg_setup->index = div->module;
reg_setup->offset = div->reg;
if (div->flags & CLKF_INDEX_STARTS_AT_ONE)
div_flags |= CLK_DIVIDER_ONE_BASED;
if (div->flags & CLKF_INDEX_POWER_OF_TWO)
div_flags |= CLK_DIVIDER_POWER_OF_TWO;
if (div->flags & CLKF_SET_RATE_PARENT)
flags |= CLK_SET_RATE_PARENT;
table = _get_div_table_from_setup(div, &width);
if (IS_ERR(table))
return (struct clk *)table;
clk = _register_divider(NULL, setup->name, div->parent,
flags, (void __iomem *)reg, div->bit_shift,
width, div_flags, table);
if (IS_ERR(clk))
kfree(table);
return clk;
}
clk: ti: LLVMLinux: Move __init outside of type definition As written, the __init for ti_clk_get_div_table is in the middle of the return type. The gcc documentation indicates that section attributes should be added to the end of the function declaration: extern void foobar (void) __attribute__ ((section ("bar"))); However gcc seems to be very permissive with where attributes can be placed. clang on the other hand isn't so permissive, and fails if you put the section definition in the middle of the return type: drivers/clk/ti/divider.c:298:28: error: expected ';' after struct static struct clk_div_table ^ ; drivers/clk/ti/divider.c:298:1: warning: 'static' ignored on this declaration [-Wmissing-declarations] static struct clk_div_table ^ drivers/clk/ti/divider.c:299:9: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int] __init *ti_clk_get_div_table(struct device_node *node) ~~~~~~ ^ drivers/clk/ti/divider.c:345:9: warning: incompatible pointer types returning 'struct clk_div_table *' from a function with result type 'int *' [-Wincompatible-pointer-types] return table; ^~~~~ drivers/clk/ti/divider.c:419:9: warning: incompatible pointer types assigning to 'const struct clk_div_table *' from 'int *' [-Wincompatible-pointer-types] *table = ti_clk_get_div_table(node); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~ 3 warnings and 2 errors generated. By convention, most of the kernel code puts section attributes between the return type and function name. In the case where the return type is a pointer, it's important to place the '*' on left of the __init. This updated code works for both gcc and clang. Signed-off-by: Behan Webster <behanw@converseincode.com> Reviewed-by: Mark Charlebois <charlebm@gmail.com> Reviewed-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Tero Kristo <t-kristo@ti.com>
2014-09-27 07:31:48 +07:00
static struct clk_div_table *
__init ti_clk_get_div_table(struct device_node *node)
{
struct clk_div_table *table;
const __be32 *divspec;
u32 val;
u32 num_div;
u32 valid_div;
int i;
divspec = of_get_property(node, "ti,dividers", &num_div);
if (!divspec)
return NULL;
num_div /= 4;
valid_div = 0;
/* Determine required size for divider table */
for (i = 0; i < num_div; i++) {
of_property_read_u32_index(node, "ti,dividers", i, &val);
if (val)
valid_div++;
}
if (!valid_div) {
pr_err("no valid dividers for %s table\n", node->name);
return ERR_PTR(-EINVAL);
}
table = kzalloc(sizeof(*table) * (valid_div + 1), GFP_KERNEL);
if (!table)
return ERR_PTR(-ENOMEM);
valid_div = 0;
for (i = 0; i < num_div; i++) {
of_property_read_u32_index(node, "ti,dividers", i, &val);
if (val) {
table[valid_div].div = val;
table[valid_div].val = i;
valid_div++;
}
}
return table;
}
static int _get_divider_width(struct device_node *node,
const struct clk_div_table *table,
u8 flags)
{
u32 min_div;
u32 max_div;
u32 val = 0;
u32 div;
if (!table) {
/* Clk divider table not provided, determine min/max divs */
if (of_property_read_u32(node, "ti,min-div", &min_div))
min_div = 1;
if (of_property_read_u32(node, "ti,max-div", &max_div)) {
pr_err("no max-div for %s!\n", node->name);
return -EINVAL;
}
/* Determine bit width for the field */
if (flags & CLK_DIVIDER_ONE_BASED)
val = 1;
div = min_div;
while (div < max_div) {
if (flags & CLK_DIVIDER_POWER_OF_TWO)
div <<= 1;
else
div++;
val++;
}
} else {
div = 0;
while (table[div].div) {
val = table[div].val;
div++;
}
}
return fls(val);
}
static int __init ti_clk_divider_populate(struct device_node *node,
void __iomem **reg, const struct clk_div_table **table,
u32 *flags, u8 *div_flags, u8 *width, u8 *shift)
{
u32 val;
*reg = ti_clk_get_reg_addr(node, 0);
if (IS_ERR(*reg))
return PTR_ERR(*reg);
if (!of_property_read_u32(node, "ti,bit-shift", &val))
*shift = val;
else
*shift = 0;
*flags = 0;
*div_flags = 0;
if (of_property_read_bool(node, "ti,index-starts-at-one"))
*div_flags |= CLK_DIVIDER_ONE_BASED;
if (of_property_read_bool(node, "ti,index-power-of-two"))
*div_flags |= CLK_DIVIDER_POWER_OF_TWO;
if (of_property_read_bool(node, "ti,set-rate-parent"))
*flags |= CLK_SET_RATE_PARENT;
*table = ti_clk_get_div_table(node);
if (IS_ERR(*table))
return PTR_ERR(*table);
*width = _get_divider_width(node, *table, *div_flags);
return 0;
}
/**
* of_ti_divider_clk_setup - Setup function for simple div rate clock
* @node: device node for this clock
*
* Sets up a basic divider clock.
*/
static void __init of_ti_divider_clk_setup(struct device_node *node)
{
struct clk *clk;
const char *parent_name;
void __iomem *reg;
u8 clk_divider_flags = 0;
u8 width = 0;
u8 shift = 0;
const struct clk_div_table *table = NULL;
u32 flags = 0;
parent_name = of_clk_get_parent_name(node, 0);
if (ti_clk_divider_populate(node, &reg, &table, &flags,
&clk_divider_flags, &width, &shift))
goto cleanup;
clk = _register_divider(NULL, node->name, parent_name, flags, reg,
shift, width, clk_divider_flags, table);
if (!IS_ERR(clk)) {
of_clk_add_provider(node, of_clk_src_simple_get, clk);
of_ti_clk_autoidle_setup(node);
return;
}
cleanup:
kfree(table);
}
CLK_OF_DECLARE(divider_clk, "ti,divider-clock", of_ti_divider_clk_setup);
static void __init of_ti_composite_divider_clk_setup(struct device_node *node)
{
struct clk_divider *div;
u32 val;
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div)
return;
if (ti_clk_divider_populate(node, &div->reg, &div->table, &val,
&div->flags, &div->width, &div->shift) < 0)
goto cleanup;
if (!ti_clk_add_component(node, &div->hw, CLK_COMPONENT_TYPE_DIVIDER))
return;
cleanup:
kfree(div->table);
kfree(div);
}
CLK_OF_DECLARE(ti_composite_divider_clk, "ti,composite-divider-clock",
of_ti_composite_divider_clk_setup);