113 lines
2.7 KiB
C
113 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2016 Synopsys, Inc. All rights reserved.
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*/
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#include <common.h>
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#include <dm.h>
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#include <errno.h>
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#include <timer.h>
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#include <asm/arcregs.h>
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#include <asm/io.h>
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DECLARE_GLOBAL_DATA_PTR;
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#define NH_MODE (1 << 1)
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/*
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* ARC timer control registers are mapped to auxiliary address space.
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* There are special ARC asm command to access that addresses.
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* Therefore we use built-in functions to read from and write to timer
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* control register.
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*/
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/* Driver private data. Contains timer id. Could be either 0 or 1. */
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struct arc_timer_priv {
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uint timer_id;
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};
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static int arc_timer_get_count(struct udevice *dev, u64 *count)
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{
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u32 val = 0;
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struct arc_timer_priv *priv = dev_get_priv(dev);
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switch (priv->timer_id) {
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case 0:
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val = read_aux_reg(ARC_AUX_TIMER0_CNT);
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break;
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case 1:
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val = read_aux_reg(ARC_AUX_TIMER1_CNT);
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break;
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}
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*count = timer_conv_64(val);
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return 0;
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}
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static int arc_timer_probe(struct udevice *dev)
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{
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int id;
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struct arc_timer_priv *priv = dev_get_priv(dev);
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/* Get registers offset and size */
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id = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", -1);
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if (id < 0)
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return -EINVAL;
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if (id > 1)
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return -ENXIO;
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priv->timer_id = (uint)id;
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/*
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* In ARC core there're special registers (Auxiliary or AUX) in its
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* separate memory space that are used for accessing some hardware
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* features of the core. They are not mapped in normal memory space
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* and also always have the same location regardless core configuration.
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* Thus to simplify understanding of the programming model we chose to
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* access AUX regs of Timer0 and Timer1 separately instead of using
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* offsets from some base address.
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*/
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switch (priv->timer_id) {
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case 0:
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/* Disable timer if CPU is halted */
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write_aux_reg(ARC_AUX_TIMER0_CTRL, NH_MODE);
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/* Set max value for counter/timer */
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write_aux_reg(ARC_AUX_TIMER0_LIMIT, 0xffffffff);
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/* Set initial count value and restart counter/timer */
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write_aux_reg(ARC_AUX_TIMER0_CNT, 0);
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break;
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case 1:
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/* Disable timer if CPU is halted */
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write_aux_reg(ARC_AUX_TIMER1_CTRL, NH_MODE);
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/* Set max value for counter/timer */
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write_aux_reg(ARC_AUX_TIMER1_LIMIT, 0xffffffff);
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/* Set initial count value and restart counter/timer */
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write_aux_reg(ARC_AUX_TIMER1_CNT, 0);
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break;
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}
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return 0;
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}
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static const struct timer_ops arc_timer_ops = {
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.get_count = arc_timer_get_count,
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};
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static const struct udevice_id arc_timer_ids[] = {
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{ .compatible = "snps,arc-timer" },
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{}
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};
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U_BOOT_DRIVER(arc_timer) = {
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.name = "arc_timer",
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.id = UCLASS_TIMER,
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.of_match = arc_timer_ids,
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.probe = arc_timer_probe,
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.ops = &arc_timer_ops,
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.flags = DM_FLAG_PRE_RELOC,
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.priv_auto_alloc_size = sizeof(struct arc_timer_priv),
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};
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