271 lines
6.8 KiB
C
271 lines
6.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* R-Car Gen3 Clock Pulse Generator Library
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*
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* Copyright (C) 2015-2018 Glider bvba
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* Copyright (C) 2019 Renesas Electronics Corp.
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*
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* Based on clk-rcar-gen3.c
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*
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* Copyright (C) 2015 Renesas Electronics Corp.
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*/
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#include <linux/clk.h>
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#include <linux/clk-provider.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/pm.h>
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#include <linux/slab.h>
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#include <linux/sys_soc.h>
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#include "rcar-cpg-lib.h"
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spinlock_t cpg_lock;
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void cpg_reg_modify(void __iomem *reg, u32 clear, u32 set)
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{
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unsigned long flags;
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u32 val;
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spin_lock_irqsave(&cpg_lock, flags);
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val = readl(reg);
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val &= ~clear;
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val |= set;
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writel(val, reg);
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spin_unlock_irqrestore(&cpg_lock, flags);
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};
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static int cpg_simple_notifier_call(struct notifier_block *nb,
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unsigned long action, void *data)
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{
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struct cpg_simple_notifier *csn =
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container_of(nb, struct cpg_simple_notifier, nb);
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switch (action) {
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case PM_EVENT_SUSPEND:
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csn->saved = readl(csn->reg);
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return NOTIFY_OK;
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case PM_EVENT_RESUME:
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writel(csn->saved, csn->reg);
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return NOTIFY_OK;
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}
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return NOTIFY_DONE;
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}
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void cpg_simple_notifier_register(struct raw_notifier_head *notifiers,
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struct cpg_simple_notifier *csn)
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{
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csn->nb.notifier_call = cpg_simple_notifier_call;
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raw_notifier_chain_register(notifiers, &csn->nb);
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}
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/*
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* SDn Clock
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*/
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#define CPG_SD_STP_HCK BIT(9)
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#define CPG_SD_STP_CK BIT(8)
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#define CPG_SD_STP_MASK (CPG_SD_STP_HCK | CPG_SD_STP_CK)
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#define CPG_SD_FC_MASK (0x7 << 2 | 0x3 << 0)
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#define CPG_SD_DIV_TABLE_DATA(stp_hck, sd_srcfc, sd_fc, sd_div) \
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{ \
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.val = ((stp_hck) ? CPG_SD_STP_HCK : 0) | \
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((sd_srcfc) << 2) | \
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((sd_fc) << 0), \
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.div = (sd_div), \
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}
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struct sd_div_table {
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u32 val;
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unsigned int div;
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};
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struct sd_clock {
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struct clk_hw hw;
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const struct sd_div_table *div_table;
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struct cpg_simple_notifier csn;
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unsigned int div_num;
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unsigned int cur_div_idx;
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};
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/* SDn divider
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* sd_srcfc sd_fc div
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* stp_hck (div) (div) = sd_srcfc x sd_fc
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*---------------------------------------------------------
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* 0 0 (1) 1 (4) 4 : SDR104 / HS200 / HS400 (8 TAP)
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* 0 1 (2) 1 (4) 8 : SDR50
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* 1 2 (4) 1 (4) 16 : HS / SDR25
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* 1 3 (8) 1 (4) 32 : NS / SDR12
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* 1 4 (16) 1 (4) 64
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* 0 0 (1) 0 (2) 2
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* 0 1 (2) 0 (2) 4 : SDR104 / HS200 / HS400 (4 TAP)
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* 1 2 (4) 0 (2) 8
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* 1 3 (8) 0 (2) 16
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* 1 4 (16) 0 (2) 32
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*
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* NOTE: There is a quirk option to ignore the first row of the dividers
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* table when searching for suitable settings. This is because HS400 on
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* early ES versions of H3 and M3-W requires a specific setting to work.
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*/
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static const struct sd_div_table cpg_sd_div_table[] = {
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/* CPG_SD_DIV_TABLE_DATA(stp_hck, sd_srcfc, sd_fc, sd_div) */
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CPG_SD_DIV_TABLE_DATA(0, 0, 1, 4),
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CPG_SD_DIV_TABLE_DATA(0, 1, 1, 8),
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CPG_SD_DIV_TABLE_DATA(1, 2, 1, 16),
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CPG_SD_DIV_TABLE_DATA(1, 3, 1, 32),
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CPG_SD_DIV_TABLE_DATA(1, 4, 1, 64),
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CPG_SD_DIV_TABLE_DATA(0, 0, 0, 2),
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CPG_SD_DIV_TABLE_DATA(0, 1, 0, 4),
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CPG_SD_DIV_TABLE_DATA(1, 2, 0, 8),
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CPG_SD_DIV_TABLE_DATA(1, 3, 0, 16),
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CPG_SD_DIV_TABLE_DATA(1, 4, 0, 32),
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};
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#define to_sd_clock(_hw) container_of(_hw, struct sd_clock, hw)
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static int cpg_sd_clock_enable(struct clk_hw *hw)
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{
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struct sd_clock *clock = to_sd_clock(hw);
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cpg_reg_modify(clock->csn.reg, CPG_SD_STP_MASK,
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clock->div_table[clock->cur_div_idx].val &
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CPG_SD_STP_MASK);
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return 0;
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}
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static void cpg_sd_clock_disable(struct clk_hw *hw)
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{
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struct sd_clock *clock = to_sd_clock(hw);
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cpg_reg_modify(clock->csn.reg, 0, CPG_SD_STP_MASK);
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}
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static int cpg_sd_clock_is_enabled(struct clk_hw *hw)
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{
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struct sd_clock *clock = to_sd_clock(hw);
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return !(readl(clock->csn.reg) & CPG_SD_STP_MASK);
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}
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static unsigned long cpg_sd_clock_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct sd_clock *clock = to_sd_clock(hw);
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return DIV_ROUND_CLOSEST(parent_rate,
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clock->div_table[clock->cur_div_idx].div);
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}
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static int cpg_sd_clock_determine_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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unsigned long best_rate = ULONG_MAX, diff_min = ULONG_MAX;
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struct sd_clock *clock = to_sd_clock(hw);
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unsigned long calc_rate, diff;
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unsigned int i;
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for (i = 0; i < clock->div_num; i++) {
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calc_rate = DIV_ROUND_CLOSEST(req->best_parent_rate,
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clock->div_table[i].div);
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if (calc_rate < req->min_rate || calc_rate > req->max_rate)
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continue;
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diff = calc_rate > req->rate ? calc_rate - req->rate
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: req->rate - calc_rate;
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if (diff < diff_min) {
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best_rate = calc_rate;
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diff_min = diff;
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}
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}
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if (best_rate == ULONG_MAX)
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return -EINVAL;
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req->rate = best_rate;
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return 0;
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}
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static int cpg_sd_clock_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 sd_clock *clock = to_sd_clock(hw);
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unsigned int i;
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for (i = 0; i < clock->div_num; i++)
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if (rate == DIV_ROUND_CLOSEST(parent_rate,
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clock->div_table[i].div))
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break;
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if (i >= clock->div_num)
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return -EINVAL;
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clock->cur_div_idx = i;
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cpg_reg_modify(clock->csn.reg, CPG_SD_STP_MASK | CPG_SD_FC_MASK,
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clock->div_table[i].val &
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(CPG_SD_STP_MASK | CPG_SD_FC_MASK));
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return 0;
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}
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static const struct clk_ops cpg_sd_clock_ops = {
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.enable = cpg_sd_clock_enable,
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.disable = cpg_sd_clock_disable,
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.is_enabled = cpg_sd_clock_is_enabled,
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.recalc_rate = cpg_sd_clock_recalc_rate,
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.determine_rate = cpg_sd_clock_determine_rate,
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.set_rate = cpg_sd_clock_set_rate,
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};
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struct clk * __init cpg_sd_clk_register(const char *name,
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void __iomem *base, unsigned int offset, const char *parent_name,
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struct raw_notifier_head *notifiers, bool skip_first)
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{
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struct clk_init_data init;
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struct sd_clock *clock;
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struct clk *clk;
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u32 val;
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clock = kzalloc(sizeof(*clock), GFP_KERNEL);
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if (!clock)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &cpg_sd_clock_ops;
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init.flags = CLK_SET_RATE_PARENT;
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init.parent_names = &parent_name;
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init.num_parents = 1;
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clock->csn.reg = base + offset;
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clock->hw.init = &init;
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clock->div_table = cpg_sd_div_table;
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clock->div_num = ARRAY_SIZE(cpg_sd_div_table);
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if (skip_first) {
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clock->div_table++;
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clock->div_num--;
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}
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val = readl(clock->csn.reg) & ~CPG_SD_FC_MASK;
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val |= CPG_SD_STP_MASK | (clock->div_table[0].val & CPG_SD_FC_MASK);
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writel(val, clock->csn.reg);
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clk = clk_register(NULL, &clock->hw);
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if (IS_ERR(clk))
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goto free_clock;
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cpg_simple_notifier_register(notifiers, &clock->csn);
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return clk;
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free_clock:
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kfree(clock);
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return clk;
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}
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