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- /*
- * 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_hw_get_name(&br->clkr.hw);
- /* 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);
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