350 lines
9.8 KiB
C
350 lines
9.8 KiB
C
/*
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* Copyright (c) 2012-2017, NVIDIA CORPORATION. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/clk-provider.h>
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#include <linux/clk.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <soc/tegra/tegra-dvfs.h>
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#include "clk.h"
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static u8 clk_periph_get_parent(struct clk_hw *hw)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *mux_ops = periph->mux_ops;
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struct clk_hw *mux_hw = &periph->mux.hw;
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__clk_hw_set_clk(mux_hw, hw);
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return mux_ops->get_parent(mux_hw);
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}
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static int clk_periph_set_parent(struct clk_hw *hw, u8 index)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *mux_ops = periph->mux_ops;
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struct clk_hw *mux_hw = &periph->mux.hw;
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__clk_hw_set_clk(mux_hw, hw);
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return mux_ops->set_parent(mux_hw, index);
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}
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static unsigned long clk_periph_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *div_ops = periph->div_ops;
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struct clk_hw *div_hw = &periph->divider.hw;
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__clk_hw_set_clk(div_hw, hw);
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return div_ops->recalc_rate(div_hw, parent_rate);
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}
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static int clk_periph_determine_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *div_ops = periph->div_ops;
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struct clk_hw *div_hw = &periph->divider.hw;
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__clk_hw_set_clk(div_hw, hw);
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return div_ops->determine_rate(div_hw, req);
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}
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static int set_request_parent(struct clk_hw *hw, struct clk_rate_request *req,
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u8 parent_idx)
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{
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struct clk_hw *parent_hw;
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unsigned long parent_rate;
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parent_hw = clk_hw_get_parent_by_index(hw, parent_idx);
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if (!parent_hw)
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return -EINVAL;
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parent_rate = clk_hw_get_rate(parent_hw);
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if (!parent_rate)
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return -EINVAL;
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req->best_parent_hw = parent_hw;
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req->best_parent_rate = parent_rate;
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return 0;
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}
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static int clk_periph_determine_reparent_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *div_ops = periph->div_ops;
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struct clk_hw *div_hw = &periph->divider.hw;
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struct clk_rate_request low_rate_req = { };
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unsigned long rate = req->rate;
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__clk_hw_set_clk(div_hw, hw);
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/*
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* First try to use low-rate parent. Keep it if derived rate is below
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* low-rate threshold or matches target exactly.
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*/
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if (set_request_parent(hw, req, periph->rpolicy.low_rate_parent_idx))
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return -EINVAL;
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if (div_ops->determine_rate(div_hw, req))
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return -EINVAL;
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if (req->rate == rate || req->rate <= periph->rpolicy.threshold)
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return 0;
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low_rate_req = *req;
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req->rate = rate; /* restore target */
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/*
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* Now try to use high-rate parent. Keep it if derived rate is below
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* rate reached from low-rate parent or low-rate parent is below target.
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* Otherwise fall back on low-rate parent. This selection policy assumes
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* that divider output rate is rounded up (divider rounded down), and
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* best parent provides lowest rate above the target.
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*/
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if (set_request_parent(hw, req, periph->rpolicy.high_rate_parent_idx))
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return -EINVAL;
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if (div_ops->determine_rate(div_hw, req))
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return -EINVAL;
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if (low_rate_req.rate < rate || req->rate < low_rate_req.rate)
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return 0;
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*req = low_rate_req;
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return 0;
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}
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static int clk_periph_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *div_ops = periph->div_ops;
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struct clk_hw *div_hw = &periph->divider.hw;
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__clk_hw_set_clk(div_hw, hw);
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return div_ops->set_rate(div_hw, rate, parent_rate);
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}
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static int clk_periph_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate, u8 index)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *mux_ops = periph->mux_ops;
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struct clk_hw *mux_hw = &periph->mux.hw;
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const struct clk_ops *div_ops = periph->div_ops;
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struct clk_hw *div_hw = &periph->divider.hw;
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struct clk_hw *old_phw;
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unsigned long old_prate;
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int ret;
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__clk_hw_set_clk(mux_hw, hw);
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__clk_hw_set_clk(div_hw, hw);
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old_phw = clk_hw_get_parent_by_index(hw, mux_ops->get_parent(mux_hw));
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if (!old_phw)
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return -EINVAL;
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old_prate = clk_hw_get_rate(old_phw);
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if (!old_prate)
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return -EINVAL;
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if (old_prate < parent_rate) {
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ret = div_ops->set_rate(div_hw, rate * old_prate / parent_rate,
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old_prate);
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if (ret)
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return ret;
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}
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ret = mux_ops->set_parent(mux_hw, index);
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if (ret)
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return ret;
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return div_ops->set_rate(div_hw, rate, parent_rate);
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}
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static int clk_periph_is_enabled(struct clk_hw *hw)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *gate_ops = periph->gate_ops;
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struct clk_hw *gate_hw = &periph->gate.hw;
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__clk_hw_set_clk(gate_hw, hw);
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return gate_ops->is_enabled(gate_hw);
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}
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static int clk_periph_enable(struct clk_hw *hw)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *gate_ops = periph->gate_ops;
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struct clk_hw *gate_hw = &periph->gate.hw;
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__clk_hw_set_clk(gate_hw, hw);
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return gate_ops->enable(gate_hw);
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}
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static void clk_periph_disable(struct clk_hw *hw)
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{
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struct tegra_clk_periph *periph = to_clk_periph(hw);
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const struct clk_ops *gate_ops = periph->gate_ops;
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struct clk_hw *gate_hw = &periph->gate.hw;
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gate_ops->disable(gate_hw);
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}
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static int clk_periph_prepare(struct clk_hw *hw)
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{
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return tegra_dvfs_set_rate(hw->clk, clk_hw_get_rate(hw));
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}
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static void clk_periph_unprepare(struct clk_hw *hw)
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{
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tegra_dvfs_set_rate(hw->clk, 0);
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}
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const struct clk_ops tegra_clk_periph_ops = {
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.get_parent = clk_periph_get_parent,
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.set_parent = clk_periph_set_parent,
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.recalc_rate = clk_periph_recalc_rate,
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.determine_rate = clk_periph_determine_rate,
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.set_rate = clk_periph_set_rate,
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.is_enabled = clk_periph_is_enabled,
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.enable = clk_periph_enable,
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.disable = clk_periph_disable,
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.prepare = clk_periph_prepare,
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.unprepare = clk_periph_unprepare,
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};
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static const struct clk_ops tegra_clk_periph_nodiv_ops = {
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.get_parent = clk_periph_get_parent,
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.set_parent = clk_periph_set_parent,
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.is_enabled = clk_periph_is_enabled,
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.enable = clk_periph_enable,
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.disable = clk_periph_disable,
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.prepare = clk_periph_prepare,
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.unprepare = clk_periph_unprepare,
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};
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static const struct clk_ops tegra_clk_periph_no_gate_ops = {
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.get_parent = clk_periph_get_parent,
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.set_parent = clk_periph_set_parent,
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.recalc_rate = clk_periph_recalc_rate,
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.determine_rate = clk_periph_determine_rate,
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.set_rate = clk_periph_set_rate,
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.prepare = clk_periph_prepare,
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.unprepare = clk_periph_unprepare,
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};
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const struct clk_ops tegra_clk_periph_reparent_ops = {
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.get_parent = clk_periph_get_parent,
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.set_parent = clk_periph_set_parent,
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.recalc_rate = clk_periph_recalc_rate,
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.determine_rate = clk_periph_determine_reparent_rate,
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.set_rate = clk_periph_set_rate,
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.set_rate_and_parent = clk_periph_set_rate_and_parent,
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.is_enabled = clk_periph_is_enabled,
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.enable = clk_periph_enable,
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.disable = clk_periph_disable,
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.prepare = clk_periph_prepare,
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.unprepare = clk_periph_unprepare,
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};
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static struct clk *_tegra_clk_register_periph(const char *name,
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const char * const *parent_names, int num_parents,
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struct tegra_clk_periph *periph,
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void __iomem *clk_base, u32 offset,
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unsigned long flags)
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{
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struct clk *clk;
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struct clk_init_data init;
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const struct tegra_clk_periph_regs *bank;
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bool div = !(periph->gate.flags & TEGRA_PERIPH_NO_DIV);
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if (periph->gate.flags & TEGRA_PERIPH_NO_DIV) {
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flags |= CLK_SET_RATE_PARENT;
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init.ops = &tegra_clk_periph_nodiv_ops;
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} else if (periph->gate.flags & TEGRA_PERIPH_NO_GATE) {
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init.ops = &tegra_clk_periph_no_gate_ops;
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} else if (periph->rpolicy.threshold) {
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if (periph->divider.flags & TEGRA_DIVIDER_ROUND_UP) {
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WARN(1, "%s: %s: No reparenting with div round up\n",
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__func__, name);
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init.ops = &tegra_clk_periph_ops;
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} else {
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init.ops = &tegra_clk_periph_reparent_ops;
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}
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} else
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init.ops = &tegra_clk_periph_ops;
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init.name = name;
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init.flags = flags;
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init.parent_names = parent_names;
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init.num_parents = num_parents;
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bank = get_reg_bank(periph->gate.clk_num);
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if (!bank)
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return ERR_PTR(-EINVAL);
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/* Data in .init is copied by clk_register(), so stack variable OK */
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periph->hw.init = &init;
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periph->magic = TEGRA_CLK_PERIPH_MAGIC;
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periph->mux.reg = clk_base + offset;
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periph->divider.reg = div ? (clk_base + offset) : NULL;
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periph->gate.clk_base = clk_base;
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periph->gate.regs = bank;
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periph->gate.enable_refcnt = periph_clk_enb_refcnt;
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clk = clk_register(NULL, &periph->hw);
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if (IS_ERR(clk))
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return clk;
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periph->mux.hw.clk = clk;
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periph->divider.hw.clk = div ? clk : NULL;
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periph->gate.hw.clk = clk;
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return clk;
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}
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struct clk *tegra_clk_register_periph(const char *name,
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const char * const *parent_names, int num_parents,
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struct tegra_clk_periph *periph, void __iomem *clk_base,
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u32 offset, unsigned long flags)
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{
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return _tegra_clk_register_periph(name, parent_names, num_parents,
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periph, clk_base, offset, flags);
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}
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struct clk *tegra_clk_register_periph_nodiv(const char *name,
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const char * const *parent_names, int num_parents,
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struct tegra_clk_periph *periph, void __iomem *clk_base,
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u32 offset)
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{
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periph->gate.flags |= TEGRA_PERIPH_NO_DIV;
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return _tegra_clk_register_periph(name, parent_names, num_parents,
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periph, clk_base, offset, CLK_SET_RATE_PARENT);
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}
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