| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * StarFive JH71X0 Clock Generator Driver |
| * |
| * Copyright (C) 2021-2022 Emil Renner Berthing <kernel@esmil.dk> |
| */ |
| |
| #include <linux/clk-provider.h> |
| #include <linux/debugfs.h> |
| #include <linux/device.h> |
| #include <linux/io.h> |
| |
| #include "clk-starfive-jh71x0.h" |
| |
| static struct jh71x0_clk *jh71x0_clk_from(struct clk_hw *hw) |
| { |
| return container_of(hw, struct jh71x0_clk, hw); |
| } |
| |
| static struct jh71x0_clk_priv *jh71x0_priv_from(struct jh71x0_clk *clk) |
| { |
| return container_of(clk, struct jh71x0_clk_priv, reg[clk->idx]); |
| } |
| |
| static u32 jh71x0_clk_reg_get(struct jh71x0_clk *clk) |
| { |
| struct jh71x0_clk_priv *priv = jh71x0_priv_from(clk); |
| void __iomem *reg = priv->base + 4 * clk->idx; |
| |
| return readl_relaxed(reg); |
| } |
| |
| static void jh71x0_clk_reg_rmw(struct jh71x0_clk *clk, u32 mask, u32 value) |
| { |
| struct jh71x0_clk_priv *priv = jh71x0_priv_from(clk); |
| void __iomem *reg = priv->base + 4 * clk->idx; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&priv->rmw_lock, flags); |
| value |= readl_relaxed(reg) & ~mask; |
| writel_relaxed(value, reg); |
| spin_unlock_irqrestore(&priv->rmw_lock, flags); |
| } |
| |
| static int jh71x0_clk_enable(struct clk_hw *hw) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| |
| jh71x0_clk_reg_rmw(clk, JH71X0_CLK_ENABLE, JH71X0_CLK_ENABLE); |
| return 0; |
| } |
| |
| static void jh71x0_clk_disable(struct clk_hw *hw) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| |
| jh71x0_clk_reg_rmw(clk, JH71X0_CLK_ENABLE, 0); |
| } |
| |
| static int jh71x0_clk_is_enabled(struct clk_hw *hw) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| |
| return !!(jh71x0_clk_reg_get(clk) & JH71X0_CLK_ENABLE); |
| } |
| |
| static unsigned long jh71x0_clk_recalc_rate(struct clk_hw *hw, |
| unsigned long parent_rate) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| u32 div = jh71x0_clk_reg_get(clk) & JH71X0_CLK_DIV_MASK; |
| |
| return div ? parent_rate / div : 0; |
| } |
| |
| static int jh71x0_clk_determine_rate(struct clk_hw *hw, |
| struct clk_rate_request *req) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| unsigned long parent = req->best_parent_rate; |
| unsigned long rate = clamp(req->rate, req->min_rate, req->max_rate); |
| unsigned long div = min_t(unsigned long, DIV_ROUND_UP(parent, rate), clk->max_div); |
| unsigned long result = parent / div; |
| |
| /* |
| * we want the result clamped by min_rate and max_rate if possible: |
| * case 1: div hits the max divider value, which means it's less than |
| * parent / rate, so the result is greater than rate and min_rate in |
| * particular. we can't do anything about result > max_rate because the |
| * divider doesn't go any further. |
| * case 2: div = DIV_ROUND_UP(parent, rate) which means the result is |
| * always lower or equal to rate and max_rate. however the result may |
| * turn out lower than min_rate, but then the next higher rate is fine: |
| * div - 1 = ceil(parent / rate) - 1 < parent / rate |
| * and thus |
| * min_rate <= rate < parent / (div - 1) |
| */ |
| if (result < req->min_rate && div > 1) |
| result = parent / (div - 1); |
| |
| req->rate = result; |
| return 0; |
| } |
| |
| static int jh71x0_clk_set_rate(struct clk_hw *hw, |
| unsigned long rate, |
| unsigned long parent_rate) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| unsigned long div = clamp(DIV_ROUND_CLOSEST(parent_rate, rate), |
| 1UL, (unsigned long)clk->max_div); |
| |
| jh71x0_clk_reg_rmw(clk, JH71X0_CLK_DIV_MASK, div); |
| return 0; |
| } |
| |
| static unsigned long jh71x0_clk_frac_recalc_rate(struct clk_hw *hw, |
| unsigned long parent_rate) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| u32 reg = jh71x0_clk_reg_get(clk); |
| unsigned long div100 = 100 * (reg & JH71X0_CLK_INT_MASK) + |
| ((reg & JH71X0_CLK_FRAC_MASK) >> JH71X0_CLK_FRAC_SHIFT); |
| |
| return (div100 >= JH71X0_CLK_FRAC_MIN) ? 100 * parent_rate / div100 : 0; |
| } |
| |
| static int jh71x0_clk_frac_determine_rate(struct clk_hw *hw, |
| struct clk_rate_request *req) |
| { |
| unsigned long parent100 = 100 * req->best_parent_rate; |
| unsigned long rate = clamp(req->rate, req->min_rate, req->max_rate); |
| unsigned long div100 = clamp(DIV_ROUND_CLOSEST(parent100, rate), |
| JH71X0_CLK_FRAC_MIN, JH71X0_CLK_FRAC_MAX); |
| unsigned long result = parent100 / div100; |
| |
| /* clamp the result as in jh71x0_clk_determine_rate() above */ |
| if (result > req->max_rate && div100 < JH71X0_CLK_FRAC_MAX) |
| result = parent100 / (div100 + 1); |
| if (result < req->min_rate && div100 > JH71X0_CLK_FRAC_MIN) |
| result = parent100 / (div100 - 1); |
| |
| req->rate = result; |
| return 0; |
| } |
| |
| static int jh71x0_clk_frac_set_rate(struct clk_hw *hw, |
| unsigned long rate, |
| unsigned long parent_rate) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| unsigned long div100 = clamp(DIV_ROUND_CLOSEST(100 * parent_rate, rate), |
| JH71X0_CLK_FRAC_MIN, JH71X0_CLK_FRAC_MAX); |
| u32 value = ((div100 % 100) << JH71X0_CLK_FRAC_SHIFT) | (div100 / 100); |
| |
| jh71x0_clk_reg_rmw(clk, JH71X0_CLK_DIV_MASK, value); |
| return 0; |
| } |
| |
| static u8 jh71x0_clk_get_parent(struct clk_hw *hw) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| u32 value = jh71x0_clk_reg_get(clk); |
| |
| return (value & JH71X0_CLK_MUX_MASK) >> JH71X0_CLK_MUX_SHIFT; |
| } |
| |
| static int jh71x0_clk_set_parent(struct clk_hw *hw, u8 index) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| u32 value = (u32)index << JH71X0_CLK_MUX_SHIFT; |
| |
| jh71x0_clk_reg_rmw(clk, JH71X0_CLK_MUX_MASK, value); |
| return 0; |
| } |
| |
| static int jh71x0_clk_get_phase(struct clk_hw *hw) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| u32 value = jh71x0_clk_reg_get(clk); |
| |
| return (value & JH71X0_CLK_INVERT) ? 180 : 0; |
| } |
| |
| static int jh71x0_clk_set_phase(struct clk_hw *hw, int degrees) |
| { |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| u32 value; |
| |
| if (degrees == 0) |
| value = 0; |
| else if (degrees == 180) |
| value = JH71X0_CLK_INVERT; |
| else |
| return -EINVAL; |
| |
| jh71x0_clk_reg_rmw(clk, JH71X0_CLK_INVERT, value); |
| return 0; |
| } |
| |
| #ifdef CONFIG_DEBUG_FS |
| static void jh71x0_clk_debug_init(struct clk_hw *hw, struct dentry *dentry) |
| { |
| static const struct debugfs_reg32 jh71x0_clk_reg = { |
| .name = "CTRL", |
| .offset = 0, |
| }; |
| struct jh71x0_clk *clk = jh71x0_clk_from(hw); |
| struct jh71x0_clk_priv *priv = jh71x0_priv_from(clk); |
| struct debugfs_regset32 *regset; |
| |
| regset = devm_kzalloc(priv->dev, sizeof(*regset), GFP_KERNEL); |
| if (!regset) |
| return; |
| |
| regset->regs = &jh71x0_clk_reg; |
| regset->nregs = 1; |
| regset->base = priv->base + 4 * clk->idx; |
| |
| debugfs_create_regset32("registers", 0400, dentry, regset); |
| } |
| #else |
| #define jh71x0_clk_debug_init NULL |
| #endif |
| |
| static const struct clk_ops jh71x0_clk_gate_ops = { |
| .enable = jh71x0_clk_enable, |
| .disable = jh71x0_clk_disable, |
| .is_enabled = jh71x0_clk_is_enabled, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_div_ops = { |
| .recalc_rate = jh71x0_clk_recalc_rate, |
| .determine_rate = jh71x0_clk_determine_rate, |
| .set_rate = jh71x0_clk_set_rate, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_fdiv_ops = { |
| .recalc_rate = jh71x0_clk_frac_recalc_rate, |
| .determine_rate = jh71x0_clk_frac_determine_rate, |
| .set_rate = jh71x0_clk_frac_set_rate, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_gdiv_ops = { |
| .enable = jh71x0_clk_enable, |
| .disable = jh71x0_clk_disable, |
| .is_enabled = jh71x0_clk_is_enabled, |
| .recalc_rate = jh71x0_clk_recalc_rate, |
| .determine_rate = jh71x0_clk_determine_rate, |
| .set_rate = jh71x0_clk_set_rate, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_mux_ops = { |
| .determine_rate = __clk_mux_determine_rate, |
| .set_parent = jh71x0_clk_set_parent, |
| .get_parent = jh71x0_clk_get_parent, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_gmux_ops = { |
| .enable = jh71x0_clk_enable, |
| .disable = jh71x0_clk_disable, |
| .is_enabled = jh71x0_clk_is_enabled, |
| .determine_rate = __clk_mux_determine_rate, |
| .set_parent = jh71x0_clk_set_parent, |
| .get_parent = jh71x0_clk_get_parent, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_mdiv_ops = { |
| .recalc_rate = jh71x0_clk_recalc_rate, |
| .determine_rate = jh71x0_clk_determine_rate, |
| .get_parent = jh71x0_clk_get_parent, |
| .set_parent = jh71x0_clk_set_parent, |
| .set_rate = jh71x0_clk_set_rate, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_gmd_ops = { |
| .enable = jh71x0_clk_enable, |
| .disable = jh71x0_clk_disable, |
| .is_enabled = jh71x0_clk_is_enabled, |
| .recalc_rate = jh71x0_clk_recalc_rate, |
| .determine_rate = jh71x0_clk_determine_rate, |
| .get_parent = jh71x0_clk_get_parent, |
| .set_parent = jh71x0_clk_set_parent, |
| .set_rate = jh71x0_clk_set_rate, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| static const struct clk_ops jh71x0_clk_inv_ops = { |
| .get_phase = jh71x0_clk_get_phase, |
| .set_phase = jh71x0_clk_set_phase, |
| .debug_init = jh71x0_clk_debug_init, |
| }; |
| |
| const struct clk_ops *starfive_jh71x0_clk_ops(u32 max) |
| { |
| if (max & JH71X0_CLK_DIV_MASK) { |
| if (max & JH71X0_CLK_MUX_MASK) { |
| if (max & JH71X0_CLK_ENABLE) |
| return &jh71x0_clk_gmd_ops; |
| return &jh71x0_clk_mdiv_ops; |
| } |
| if (max & JH71X0_CLK_ENABLE) |
| return &jh71x0_clk_gdiv_ops; |
| if (max == JH71X0_CLK_FRAC_MAX) |
| return &jh71x0_clk_fdiv_ops; |
| return &jh71x0_clk_div_ops; |
| } |
| |
| if (max & JH71X0_CLK_MUX_MASK) { |
| if (max & JH71X0_CLK_ENABLE) |
| return &jh71x0_clk_gmux_ops; |
| return &jh71x0_clk_mux_ops; |
| } |
| |
| if (max & JH71X0_CLK_ENABLE) |
| return &jh71x0_clk_gate_ops; |
| |
| return &jh71x0_clk_inv_ops; |
| } |
| EXPORT_SYMBOL_GPL(starfive_jh71x0_clk_ops); |