diff options
Diffstat (limited to 'drivers/clk/qcom/clk-branch.c')
| -rw-r--r-- | drivers/clk/qcom/clk-branch.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-branch.c b/drivers/clk/qcom/clk-branch.c new file mode 100644 index 000000000000..6b4d2bcb1a53 --- /dev/null +++ b/drivers/clk/qcom/clk-branch.c @@ -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); |