clk: qcom: Add support for branches/gate clocks

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This commit is contained in:
Stephen Boyd 2014-01-15 10:47:26 -08:00 committed by Mike Turquette
parent bcd61c0f53
commit 6e0ad1b6c1
3 changed files with 216 additions and 0 deletions

View File

@ -4,3 +4,4 @@ clk-qcom-$(CONFIG_COMMON_CLK_QCOM) += clk-regmap.o
clk-qcom-$(CONFIG_COMMON_CLK_QCOM) += clk-pll.o
clk-qcom-$(CONFIG_COMMON_CLK_QCOM) += clk-rcg.o
clk-qcom-$(CONFIG_COMMON_CLK_QCOM) += clk-rcg2.o
clk-qcom-$(CONFIG_COMMON_CLK_QCOM) += clk-branch.o

View File

@ -0,0 +1,159 @@
/*
* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#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 0;
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_get_name(br->clkr.hw.clk);
/* Skip checking halt bit if the clock is in hardware gated mode */
if (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_branch_simple_ops = {
.enable = clk_enable_regmap,
.disable = clk_disable_regmap,
.is_enabled = clk_is_enabled_regmap,
};
EXPORT_SYMBOL_GPL(clk_branch_simple_ops);

View File

@ -0,0 +1,56 @@
/*
* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef __QCOM_CLK_BRANCH_H__
#define __QCOM_CLK_BRANCH_H__
#include <linux/clk-provider.h>
#include "clk-regmap.h"
/**
* struct clk_branch - gating clock with status bit and dynamic hardware gating
*
* @hwcg_reg: dynamic hardware clock gating register
* @hwcg_bit: ORed with @hwcg_reg to enable dynamic hardware clock gating
* @halt_reg: halt register
* @halt_bit: ANDed with @halt_reg to test for clock halted
* @halt_check: type of halt checking to perform
* @clkr: handle between common and hardware-specific interfaces
*
* Clock which can gate its output.
*/
struct clk_branch {
u32 hwcg_reg;
u32 halt_reg;
u8 hwcg_bit;
u8 halt_bit;
u8 halt_check;
#define BRANCH_VOTED BIT(7) /* Delay on disable */
#define BRANCH_HALT 0 /* pol: 1 = halt */
#define BRANCH_HALT_VOTED (BRANCH_HALT | BRANCH_VOTED)
#define BRANCH_HALT_ENABLE 1 /* pol: 0 = halt */
#define BRANCH_HALT_ENABLE_VOTED (BRANCH_HALT_ENABLE | BRANCH_VOTED)
#define BRANCH_HALT_DELAY 2 /* No bit to check; just delay */
struct clk_regmap clkr;
};
extern const struct clk_ops clk_branch_ops;
extern const struct clk_ops clk_branch2_ops;
extern const struct clk_ops clk_branch_simple_ops;
#define to_clk_branch(_hw) \
container_of(to_clk_regmap(_hw), struct clk_branch, clkr)
#endif