linux/drivers/clk/qcom/clk-branch.c
Bjorn Andersson 360fed4228 clk: qcom: branch: Add AON clock ops
Some clocks can only be turned on by resetting the block containing
them, provide a clock type that allow us to reference these clocks and
have the client drivers enable and "disable" them.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-11 13:34:21 -07:00

161 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/clk-provider.h>
#include <linux/regmap.h>
#include "clk-branch.h"
static bool clk_branch_in_hwcg_mode(const struct clk_branch *br)
{
u32 val;
if (!br->hwcg_reg)
return false;
regmap_read(br->clkr.regmap, br->hwcg_reg, &val);
return !!(val & BIT(br->hwcg_bit));
}
static bool clk_branch_check_halt(const struct clk_branch *br, bool enabling)
{
bool invert = (br->halt_check == BRANCH_HALT_ENABLE);
u32 val;
regmap_read(br->clkr.regmap, br->halt_reg, &val);
val &= BIT(br->halt_bit);
if (invert)
val = !val;
return !!val == !enabling;
}
#define BRANCH_CLK_OFF BIT(31)
#define BRANCH_NOC_FSM_STATUS_SHIFT 28
#define BRANCH_NOC_FSM_STATUS_MASK 0x7
#define BRANCH_NOC_FSM_STATUS_ON (0x2 << BRANCH_NOC_FSM_STATUS_SHIFT)
static bool clk_branch2_check_halt(const struct clk_branch *br, bool enabling)
{
u32 val;
u32 mask;
mask = BRANCH_NOC_FSM_STATUS_MASK << BRANCH_NOC_FSM_STATUS_SHIFT;
mask |= BRANCH_CLK_OFF;
regmap_read(br->clkr.regmap, br->halt_reg, &val);
if (enabling) {
val &= mask;
return (val & BRANCH_CLK_OFF) == 0 ||
val == BRANCH_NOC_FSM_STATUS_ON;
} else {
return val & BRANCH_CLK_OFF;
}
}
static int clk_branch_wait(const struct clk_branch *br, bool enabling,
bool (check_halt)(const struct clk_branch *, bool))
{
bool voted = br->halt_check & BRANCH_VOTED;
const char *name = clk_hw_get_name(&br->clkr.hw);
/*
* Skip checking halt bit if we're explicitly ignoring the bit or the
* clock is in hardware gated mode
*/
if (br->halt_check == BRANCH_HALT_SKIP || clk_branch_in_hwcg_mode(br))
return 0;
if (br->halt_check == BRANCH_HALT_DELAY || (!enabling && voted)) {
udelay(10);
} else if (br->halt_check == BRANCH_HALT_ENABLE ||
br->halt_check == BRANCH_HALT ||
(enabling && voted)) {
int count = 200;
while (count-- > 0) {
if (check_halt(br, enabling))
return 0;
udelay(1);
}
WARN(1, "%s status stuck at 'o%s'", name,
enabling ? "ff" : "n");
return -EBUSY;
}
return 0;
}
static int clk_branch_toggle(struct clk_hw *hw, bool en,
bool (check_halt)(const struct clk_branch *, bool))
{
struct clk_branch *br = to_clk_branch(hw);
int ret;
if (en) {
ret = clk_enable_regmap(hw);
if (ret)
return ret;
} else {
clk_disable_regmap(hw);
}
return clk_branch_wait(br, en, check_halt);
}
static int clk_branch_enable(struct clk_hw *hw)
{
return clk_branch_toggle(hw, true, clk_branch_check_halt);
}
static void clk_branch_disable(struct clk_hw *hw)
{
clk_branch_toggle(hw, false, clk_branch_check_halt);
}
const struct clk_ops clk_branch_ops = {
.enable = clk_branch_enable,
.disable = clk_branch_disable,
.is_enabled = clk_is_enabled_regmap,
};
EXPORT_SYMBOL_GPL(clk_branch_ops);
static int clk_branch2_enable(struct clk_hw *hw)
{
return clk_branch_toggle(hw, true, clk_branch2_check_halt);
}
static void clk_branch2_disable(struct clk_hw *hw)
{
clk_branch_toggle(hw, false, clk_branch2_check_halt);
}
const struct clk_ops clk_branch2_ops = {
.enable = clk_branch2_enable,
.disable = clk_branch2_disable,
.is_enabled = clk_is_enabled_regmap,
};
EXPORT_SYMBOL_GPL(clk_branch2_ops);
const struct clk_ops clk_branch2_aon_ops = {
.enable = clk_branch2_enable,
.is_enabled = clk_is_enabled_regmap,
};
EXPORT_SYMBOL_GPL(clk_branch2_aon_ops);
const struct clk_ops clk_branch_simple_ops = {
.enable = clk_enable_regmap,
.disable = clk_disable_regmap,
.is_enabled = clk_is_enabled_regmap,
};
EXPORT_SYMBOL_GPL(clk_branch_simple_ops);