312 lines
6.8 KiB
C
312 lines
6.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Microchip Image Sensor Controller (ISC) common clock driver setup
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*
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* Copyright (C) 2016 Microchip Technology, Inc.
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*
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* Author: Songjun Wu
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* Author: Eugen Hristev <eugen.hristev@microchip.com>
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*
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*/
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#include <linux/clk.h>
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#include <linux/clkdev.h>
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#include <linux/clk-provider.h>
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#include <linux/pm_runtime.h>
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#include <linux/regmap.h>
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#include "atmel-isc-regs.h"
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#include "atmel-isc.h"
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static int isc_wait_clk_stable(struct clk_hw *hw)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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struct regmap *regmap = isc_clk->regmap;
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unsigned long timeout = jiffies + usecs_to_jiffies(1000);
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unsigned int status;
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while (time_before(jiffies, timeout)) {
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regmap_read(regmap, ISC_CLKSR, &status);
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if (!(status & ISC_CLKSR_SIP))
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return 0;
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usleep_range(10, 250);
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}
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return -ETIMEDOUT;
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}
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static int isc_clk_prepare(struct clk_hw *hw)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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int ret;
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ret = pm_runtime_resume_and_get(isc_clk->dev);
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if (ret < 0)
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return ret;
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return isc_wait_clk_stable(hw);
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}
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static void isc_clk_unprepare(struct clk_hw *hw)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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isc_wait_clk_stable(hw);
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pm_runtime_put_sync(isc_clk->dev);
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}
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static int isc_clk_enable(struct clk_hw *hw)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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u32 id = isc_clk->id;
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struct regmap *regmap = isc_clk->regmap;
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unsigned long flags;
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unsigned int status;
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dev_dbg(isc_clk->dev, "ISC CLK: %s, id = %d, div = %d, parent id = %d\n",
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__func__, id, isc_clk->div, isc_clk->parent_id);
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spin_lock_irqsave(&isc_clk->lock, flags);
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regmap_update_bits(regmap, ISC_CLKCFG,
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ISC_CLKCFG_DIV_MASK(id) | ISC_CLKCFG_SEL_MASK(id),
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(isc_clk->div << ISC_CLKCFG_DIV_SHIFT(id)) |
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(isc_clk->parent_id << ISC_CLKCFG_SEL_SHIFT(id)));
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regmap_write(regmap, ISC_CLKEN, ISC_CLK(id));
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spin_unlock_irqrestore(&isc_clk->lock, flags);
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regmap_read(regmap, ISC_CLKSR, &status);
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if (status & ISC_CLK(id))
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return 0;
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else
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return -EINVAL;
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}
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static void isc_clk_disable(struct clk_hw *hw)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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u32 id = isc_clk->id;
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unsigned long flags;
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spin_lock_irqsave(&isc_clk->lock, flags);
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regmap_write(isc_clk->regmap, ISC_CLKDIS, ISC_CLK(id));
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spin_unlock_irqrestore(&isc_clk->lock, flags);
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}
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static int isc_clk_is_enabled(struct clk_hw *hw)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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u32 status;
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int ret;
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ret = pm_runtime_resume_and_get(isc_clk->dev);
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if (ret < 0)
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return 0;
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regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
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pm_runtime_put_sync(isc_clk->dev);
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return status & ISC_CLK(isc_clk->id) ? 1 : 0;
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}
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static unsigned long
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isc_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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return DIV_ROUND_CLOSEST(parent_rate, isc_clk->div + 1);
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}
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static int isc_clk_determine_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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long best_rate = -EINVAL;
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int best_diff = -1;
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unsigned int i, div;
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for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
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struct clk_hw *parent;
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unsigned long parent_rate;
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parent = clk_hw_get_parent_by_index(hw, i);
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if (!parent)
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continue;
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parent_rate = clk_hw_get_rate(parent);
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if (!parent_rate)
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continue;
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for (div = 1; div < ISC_CLK_MAX_DIV + 2; div++) {
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unsigned long rate;
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int diff;
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rate = DIV_ROUND_CLOSEST(parent_rate, div);
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diff = abs(req->rate - rate);
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if (best_diff < 0 || best_diff > diff) {
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best_rate = rate;
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best_diff = diff;
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req->best_parent_rate = parent_rate;
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req->best_parent_hw = parent;
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}
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if (!best_diff || rate < req->rate)
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break;
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}
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if (!best_diff)
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break;
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}
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dev_dbg(isc_clk->dev,
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"ISC CLK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
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__func__, best_rate,
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__clk_get_name((req->best_parent_hw)->clk),
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req->best_parent_rate);
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if (best_rate < 0)
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return best_rate;
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req->rate = best_rate;
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return 0;
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}
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static int isc_clk_set_parent(struct clk_hw *hw, u8 index)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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if (index >= clk_hw_get_num_parents(hw))
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return -EINVAL;
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isc_clk->parent_id = index;
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return 0;
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}
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static u8 isc_clk_get_parent(struct clk_hw *hw)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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return isc_clk->parent_id;
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}
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static int isc_clk_set_rate(struct clk_hw *hw,
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unsigned long rate,
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unsigned long parent_rate)
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{
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struct isc_clk *isc_clk = to_isc_clk(hw);
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u32 div;
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if (!rate)
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return -EINVAL;
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div = DIV_ROUND_CLOSEST(parent_rate, rate);
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if (div > (ISC_CLK_MAX_DIV + 1) || !div)
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return -EINVAL;
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isc_clk->div = div - 1;
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return 0;
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}
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static const struct clk_ops isc_clk_ops = {
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.prepare = isc_clk_prepare,
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.unprepare = isc_clk_unprepare,
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.enable = isc_clk_enable,
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.disable = isc_clk_disable,
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.is_enabled = isc_clk_is_enabled,
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.recalc_rate = isc_clk_recalc_rate,
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.determine_rate = isc_clk_determine_rate,
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.set_parent = isc_clk_set_parent,
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.get_parent = isc_clk_get_parent,
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.set_rate = isc_clk_set_rate,
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};
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static int isc_clk_register(struct isc_device *isc, unsigned int id)
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{
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struct regmap *regmap = isc->regmap;
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struct device_node *np = isc->dev->of_node;
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struct isc_clk *isc_clk;
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struct clk_init_data init;
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const char *clk_name = np->name;
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const char *parent_names[3];
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int num_parents;
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if (id == ISC_ISPCK && !isc->ispck_required)
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return 0;
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num_parents = of_clk_get_parent_count(np);
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if (num_parents < 1 || num_parents > 3)
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return -EINVAL;
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if (num_parents > 2 && id == ISC_ISPCK)
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num_parents = 2;
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of_clk_parent_fill(np, parent_names, num_parents);
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if (id == ISC_MCK)
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of_property_read_string(np, "clock-output-names", &clk_name);
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else
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clk_name = "isc-ispck";
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init.parent_names = parent_names;
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init.num_parents = num_parents;
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init.name = clk_name;
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init.ops = &isc_clk_ops;
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init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
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isc_clk = &isc->isc_clks[id];
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isc_clk->hw.init = &init;
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isc_clk->regmap = regmap;
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isc_clk->id = id;
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isc_clk->dev = isc->dev;
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spin_lock_init(&isc_clk->lock);
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isc_clk->clk = clk_register(isc->dev, &isc_clk->hw);
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if (IS_ERR(isc_clk->clk)) {
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dev_err(isc->dev, "%s: clock register fail\n", clk_name);
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return PTR_ERR(isc_clk->clk);
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} else if (id == ISC_MCK) {
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of_clk_add_provider(np, of_clk_src_simple_get, isc_clk->clk);
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}
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return 0;
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}
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int isc_clk_init(struct isc_device *isc)
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{
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unsigned int i;
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int ret;
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for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++)
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isc->isc_clks[i].clk = ERR_PTR(-EINVAL);
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for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) {
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ret = isc_clk_register(isc, i);
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if (ret)
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return ret;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(isc_clk_init);
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void isc_clk_cleanup(struct isc_device *isc)
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{
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unsigned int i;
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of_clk_del_provider(isc->dev->of_node);
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for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) {
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struct isc_clk *isc_clk = &isc->isc_clks[i];
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if (!IS_ERR(isc_clk->clk))
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clk_unregister(isc_clk->clk);
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}
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}
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EXPORT_SYMBOL_GPL(isc_clk_cleanup);
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