164 lines
3.7 KiB
C
164 lines
3.7 KiB
C
/*
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* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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*/
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#include <linux/clk-provider.h>
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#include <linux/clkdev.h>
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#include <linux/clk/at91_pmc.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/io.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include "pmc.h"
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#define UTMI_FIXED_MUL 40
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struct clk_utmi {
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struct clk_hw hw;
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struct at91_pmc *pmc;
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unsigned int irq;
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wait_queue_head_t wait;
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};
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#define to_clk_utmi(hw) container_of(hw, struct clk_utmi, hw)
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static irqreturn_t clk_utmi_irq_handler(int irq, void *dev_id)
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{
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struct clk_utmi *utmi = (struct clk_utmi *)dev_id;
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wake_up(&utmi->wait);
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disable_irq_nosync(utmi->irq);
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return IRQ_HANDLED;
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}
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static int clk_utmi_prepare(struct clk_hw *hw)
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{
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struct clk_utmi *utmi = to_clk_utmi(hw);
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struct at91_pmc *pmc = utmi->pmc;
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u32 tmp = pmc_read(pmc, AT91_CKGR_UCKR) | AT91_PMC_UPLLEN |
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AT91_PMC_UPLLCOUNT | AT91_PMC_BIASEN;
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pmc_write(pmc, AT91_CKGR_UCKR, tmp);
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while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_LOCKU)) {
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enable_irq(utmi->irq);
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wait_event(utmi->wait,
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pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_LOCKU);
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}
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return 0;
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}
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static int clk_utmi_is_prepared(struct clk_hw *hw)
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{
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struct clk_utmi *utmi = to_clk_utmi(hw);
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struct at91_pmc *pmc = utmi->pmc;
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return !!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_LOCKU);
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}
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static void clk_utmi_unprepare(struct clk_hw *hw)
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{
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struct clk_utmi *utmi = to_clk_utmi(hw);
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struct at91_pmc *pmc = utmi->pmc;
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u32 tmp = pmc_read(pmc, AT91_CKGR_UCKR) & ~AT91_PMC_UPLLEN;
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pmc_write(pmc, AT91_CKGR_UCKR, tmp);
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}
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static unsigned long clk_utmi_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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/* UTMI clk is a fixed clk multiplier */
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return parent_rate * UTMI_FIXED_MUL;
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}
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static const struct clk_ops utmi_ops = {
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.prepare = clk_utmi_prepare,
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.unprepare = clk_utmi_unprepare,
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.is_prepared = clk_utmi_is_prepared,
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.recalc_rate = clk_utmi_recalc_rate,
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};
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static struct clk * __init
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at91_clk_register_utmi(struct at91_pmc *pmc, unsigned int irq,
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const char *name, const char *parent_name)
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{
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int ret;
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struct clk_utmi *utmi;
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struct clk *clk = NULL;
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struct clk_init_data init;
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utmi = kzalloc(sizeof(*utmi), GFP_KERNEL);
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if (!utmi)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &utmi_ops;
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init.parent_names = parent_name ? &parent_name : NULL;
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init.num_parents = parent_name ? 1 : 0;
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init.flags = CLK_SET_RATE_GATE;
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utmi->hw.init = &init;
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utmi->pmc = pmc;
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utmi->irq = irq;
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init_waitqueue_head(&utmi->wait);
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irq_set_status_flags(utmi->irq, IRQ_NOAUTOEN);
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ret = request_irq(utmi->irq, clk_utmi_irq_handler,
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IRQF_TRIGGER_HIGH, "clk-utmi", utmi);
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if (ret) {
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kfree(utmi);
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return ERR_PTR(ret);
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}
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clk = clk_register(NULL, &utmi->hw);
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if (IS_ERR(clk)) {
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free_irq(utmi->irq, utmi);
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kfree(utmi);
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}
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return clk;
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}
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static void __init
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of_at91_clk_utmi_setup(struct device_node *np, struct at91_pmc *pmc)
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{
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unsigned int irq;
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struct clk *clk;
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const char *parent_name;
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const char *name = np->name;
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parent_name = of_clk_get_parent_name(np, 0);
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of_property_read_string(np, "clock-output-names", &name);
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irq = irq_of_parse_and_map(np, 0);
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if (!irq)
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return;
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clk = at91_clk_register_utmi(pmc, irq, name, parent_name);
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if (IS_ERR(clk))
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return;
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of_clk_add_provider(np, of_clk_src_simple_get, clk);
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return;
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}
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void __init of_at91sam9x5_clk_utmi_setup(struct device_node *np,
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struct at91_pmc *pmc)
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{
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of_at91_clk_utmi_setup(np, pmc);
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}
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