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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * TI clock autoidle support4 *5 * Copyright (C) 2013 Texas Instruments, Inc.6 *7 * Tero Kristo <t-kristo@ti.com>8 */9 10#include <linux/clk-provider.h>11#include <linux/slab.h>12#include <linux/io.h>13#include <linux/of.h>14#include <linux/of_address.h>15#include <linux/clk/ti.h>16 17#include "clock.h"18 19struct clk_ti_autoidle {20 struct clk_omap_reg reg;21 u8 shift;22 u8 flags;23 const char *name;24 struct list_head node;25};26 27#define AUTOIDLE_LOW 0x128 29static LIST_HEAD(autoidle_clks);30 31/*32 * we have some non-atomic read/write33 * operations behind it, so lets34 * take one lock for handling autoidle35 * of all clocks36 */37static DEFINE_SPINLOCK(autoidle_spinlock);38 39static int _omap2_clk_deny_idle(struct clk_hw_omap *clk)40{41 if (clk->ops && clk->ops->deny_idle) {42 unsigned long irqflags;43 44 spin_lock_irqsave(&autoidle_spinlock, irqflags);45 clk->autoidle_count++;46 if (clk->autoidle_count == 1)47 clk->ops->deny_idle(clk);48 49 spin_unlock_irqrestore(&autoidle_spinlock, irqflags);50 }51 return 0;52}53 54static int _omap2_clk_allow_idle(struct clk_hw_omap *clk)55{56 if (clk->ops && clk->ops->allow_idle) {57 unsigned long irqflags;58 59 spin_lock_irqsave(&autoidle_spinlock, irqflags);60 clk->autoidle_count--;61 if (clk->autoidle_count == 0)62 clk->ops->allow_idle(clk);63 64 spin_unlock_irqrestore(&autoidle_spinlock, irqflags);65 }66 return 0;67}68 69/**70 * omap2_clk_deny_idle - disable autoidle on an OMAP clock71 * @clk: struct clk * to disable autoidle for72 *73 * Disable autoidle on an OMAP clock.74 */75int omap2_clk_deny_idle(struct clk *clk)76{77 struct clk_hw *hw;78 79 if (!clk)80 return -EINVAL;81 82 hw = __clk_get_hw(clk);83 84 if (omap2_clk_is_hw_omap(hw)) {85 struct clk_hw_omap *c = to_clk_hw_omap(hw);86 87 return _omap2_clk_deny_idle(c);88 }89 90 return -EINVAL;91}92 93/**94 * omap2_clk_allow_idle - enable autoidle on an OMAP clock95 * @clk: struct clk * to enable autoidle for96 *97 * Enable autoidle on an OMAP clock.98 */99int omap2_clk_allow_idle(struct clk *clk)100{101 struct clk_hw *hw;102 103 if (!clk)104 return -EINVAL;105 106 hw = __clk_get_hw(clk);107 108 if (omap2_clk_is_hw_omap(hw)) {109 struct clk_hw_omap *c = to_clk_hw_omap(hw);110 111 return _omap2_clk_allow_idle(c);112 }113 114 return -EINVAL;115}116 117static void _allow_autoidle(struct clk_ti_autoidle *clk)118{119 u32 val;120 121 val = ti_clk_ll_ops->clk_readl(&clk->reg);122 123 if (clk->flags & AUTOIDLE_LOW)124 val &= ~(1 << clk->shift);125 else126 val |= (1 << clk->shift);127 128 ti_clk_ll_ops->clk_writel(val, &clk->reg);129}130 131static void _deny_autoidle(struct clk_ti_autoidle *clk)132{133 u32 val;134 135 val = ti_clk_ll_ops->clk_readl(&clk->reg);136 137 if (clk->flags & AUTOIDLE_LOW)138 val |= (1 << clk->shift);139 else140 val &= ~(1 << clk->shift);141 142 ti_clk_ll_ops->clk_writel(val, &clk->reg);143}144 145/**146 * _clk_generic_allow_autoidle_all - enable autoidle for all clocks147 *148 * Enables hardware autoidle for all registered DT clocks, which have149 * the feature.150 */151static void _clk_generic_allow_autoidle_all(void)152{153 struct clk_ti_autoidle *c;154 155 list_for_each_entry(c, &autoidle_clks, node)156 _allow_autoidle(c);157}158 159/**160 * _clk_generic_deny_autoidle_all - disable autoidle for all clocks161 *162 * Disables hardware autoidle for all registered DT clocks, which have163 * the feature.164 */165static void _clk_generic_deny_autoidle_all(void)166{167 struct clk_ti_autoidle *c;168 169 list_for_each_entry(c, &autoidle_clks, node)170 _deny_autoidle(c);171}172 173/**174 * of_ti_clk_autoidle_setup - sets up hardware autoidle for a clock175 * @node: pointer to the clock device node176 *177 * Checks if a clock has hardware autoidle support or not (check178 * for presence of 'ti,autoidle-shift' property in the device tree179 * node) and sets up the hardware autoidle feature for the clock180 * if available. If autoidle is available, the clock is also added181 * to the autoidle list for later processing. Returns 0 on success,182 * negative error value on failure.183 */184int __init of_ti_clk_autoidle_setup(struct device_node *node)185{186 u32 shift;187 struct clk_ti_autoidle *clk;188 int ret;189 190 /* Check if this clock has autoidle support or not */191 if (of_property_read_u32(node, "ti,autoidle-shift", &shift))192 return 0;193 194 clk = kzalloc(sizeof(*clk), GFP_KERNEL);195 196 if (!clk)197 return -ENOMEM;198 199 clk->shift = shift;200 clk->name = ti_dt_clk_name(node);201 ret = ti_clk_get_reg_addr(node, 0, &clk->reg);202 if (ret) {203 kfree(clk);204 return ret;205 }206 207 if (of_property_read_bool(node, "ti,invert-autoidle-bit"))208 clk->flags |= AUTOIDLE_LOW;209 210 list_add(&clk->node, &autoidle_clks);211 212 return 0;213}214 215/**216 * omap2_clk_enable_autoidle_all - enable autoidle on all OMAP clocks that217 * support it218 *219 * Enable clock autoidle on all OMAP clocks that have allow_idle220 * function pointers associated with them. This function is intended221 * to be temporary until support for this is added to the common clock222 * code. Returns 0.223 */224int omap2_clk_enable_autoidle_all(void)225{226 int ret;227 228 ret = omap2_clk_for_each(_omap2_clk_allow_idle);229 if (ret)230 return ret;231 232 _clk_generic_allow_autoidle_all();233 234 return 0;235}236 237/**238 * omap2_clk_disable_autoidle_all - disable autoidle on all OMAP clocks that239 * support it240 *241 * Disable clock autoidle on all OMAP clocks that have allow_idle242 * function pointers associated with them. This function is intended243 * to be temporary until support for this is added to the common clock244 * code. Returns 0.245 */246int omap2_clk_disable_autoidle_all(void)247{248 int ret;249 250 ret = omap2_clk_for_each(_omap2_clk_deny_idle);251 if (ret)252 return ret;253 254 _clk_generic_deny_autoidle_all();255 256 return 0;257}258