134 lines
3.0 KiB
C
134 lines
3.0 KiB
C
/*
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* TI clock autoidle support
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*
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* Copyright (C) 2013 Texas Instruments, Inc.
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*
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* Tero Kristo <t-kristo@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/clk-provider.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/clk/ti.h>
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struct clk_ti_autoidle {
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void __iomem *reg;
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u8 shift;
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u8 flags;
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const char *name;
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struct list_head node;
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};
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#define AUTOIDLE_LOW 0x1
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static LIST_HEAD(autoidle_clks);
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static void ti_allow_autoidle(struct clk_ti_autoidle *clk)
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{
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u32 val;
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val = ti_clk_ll_ops->clk_readl(clk->reg);
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if (clk->flags & AUTOIDLE_LOW)
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val &= ~(1 << clk->shift);
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else
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val |= (1 << clk->shift);
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ti_clk_ll_ops->clk_writel(val, clk->reg);
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}
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static void ti_deny_autoidle(struct clk_ti_autoidle *clk)
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{
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u32 val;
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val = ti_clk_ll_ops->clk_readl(clk->reg);
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if (clk->flags & AUTOIDLE_LOW)
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val |= (1 << clk->shift);
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else
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val &= ~(1 << clk->shift);
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ti_clk_ll_ops->clk_writel(val, clk->reg);
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}
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/**
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* of_ti_clk_allow_autoidle_all - enable autoidle for all clocks
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*
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* Enables hardware autoidle for all registered DT clocks, which have
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* the feature.
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*/
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void of_ti_clk_allow_autoidle_all(void)
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{
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struct clk_ti_autoidle *c;
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list_for_each_entry(c, &autoidle_clks, node)
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ti_allow_autoidle(c);
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}
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/**
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* of_ti_clk_deny_autoidle_all - disable autoidle for all clocks
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*
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* Disables hardware autoidle for all registered DT clocks, which have
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* the feature.
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*/
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void of_ti_clk_deny_autoidle_all(void)
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{
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struct clk_ti_autoidle *c;
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list_for_each_entry(c, &autoidle_clks, node)
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ti_deny_autoidle(c);
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}
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/**
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* of_ti_clk_autoidle_setup - sets up hardware autoidle for a clock
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* @node: pointer to the clock device node
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*
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* Checks if a clock has hardware autoidle support or not (check
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* for presence of 'ti,autoidle-shift' property in the device tree
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* node) and sets up the hardware autoidle feature for the clock
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* if available. If autoidle is available, the clock is also added
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* to the autoidle list for later processing. Returns 0 on success,
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* negative error value on failure.
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*/
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int __init of_ti_clk_autoidle_setup(struct device_node *node)
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{
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u32 shift;
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struct clk_ti_autoidle *clk;
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/* Check if this clock has autoidle support or not */
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if (of_property_read_u32(node, "ti,autoidle-shift", &shift))
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return 0;
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clk = kzalloc(sizeof(*clk), GFP_KERNEL);
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if (!clk)
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return -ENOMEM;
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clk->shift = shift;
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clk->name = node->name;
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clk->reg = ti_clk_get_reg_addr(node, 0);
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if (!clk->reg) {
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kfree(clk);
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return -EINVAL;
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}
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if (of_property_read_bool(node, "ti,invert-autoidle-bit"))
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clk->flags |= AUTOIDLE_LOW;
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list_add(&clk->node, &autoidle_clks);
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return 0;
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}
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