138 lines
2.7 KiB
C
138 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2018, STMicroelectronics - All Rights Reserved
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* Author(s): Patrice Chotard, <patrice.chotard@foss.st.com> for STMicroelectronics.
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*/
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#define LOG_CATEGORY UCLASS_TIMER
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#include <common.h>
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#include <clk.h>
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#include <dm.h>
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#include <fdtdec.h>
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#include <timer.h>
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#include <dm/device_compat.h>
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#include <linux/bitops.h>
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#include <asm/io.h>
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/* Timer control1 register */
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#define CR1_CEN BIT(0)
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#define CR1_ARPE BIT(7)
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/* Event Generation Register register */
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#define EGR_UG BIT(0)
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/* Auto reload register for free running config */
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#define GPT_FREE_RUNNING 0xFFFFFFFF
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struct stm32_timer_regs {
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u32 cr1;
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u32 cr2;
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u32 smcr;
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u32 dier;
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u32 sr;
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u32 egr;
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u32 ccmr1;
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u32 ccmr2;
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u32 ccer;
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u32 cnt;
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u32 psc;
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u32 arr;
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u32 reserved;
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u32 ccr1;
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u32 ccr2;
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u32 ccr3;
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u32 ccr4;
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u32 reserved1;
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u32 dcr;
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u32 dmar;
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u32 tim2_5_or;
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};
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struct stm32_timer_priv {
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struct stm32_timer_regs *base;
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};
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static u64 stm32_timer_get_count(struct udevice *dev)
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{
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struct stm32_timer_priv *priv = dev_get_priv(dev);
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struct stm32_timer_regs *regs = priv->base;
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return readl(®s->cnt);
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}
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static int stm32_timer_probe(struct udevice *dev)
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{
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struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
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struct stm32_timer_priv *priv = dev_get_priv(dev);
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struct stm32_timer_regs *regs;
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struct clk clk;
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fdt_addr_t addr;
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int ret;
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u32 rate, psc;
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addr = dev_read_addr(dev);
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if (addr == FDT_ADDR_T_NONE)
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return -EINVAL;
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priv->base = (struct stm32_timer_regs *)addr;
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ret = clk_get_by_index(dev, 0, &clk);
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if (ret < 0)
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return ret;
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ret = clk_enable(&clk);
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if (ret) {
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dev_err(dev, "failed to enable clock\n");
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return ret;
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}
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regs = priv->base;
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/* Stop the timer */
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clrbits_le32(®s->cr1, CR1_CEN);
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/* get timer clock */
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rate = clk_get_rate(&clk);
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/* we set timer prescaler to obtain a 1MHz timer counter frequency */
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psc = (rate / CFG_SYS_HZ_CLOCK) - 1;
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writel(psc, ®s->psc);
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/* Set timer frequency to 1MHz */
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uc_priv->clock_rate = CFG_SYS_HZ_CLOCK;
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/* Configure timer for auto-reload */
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setbits_le32(®s->cr1, CR1_ARPE);
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/* load value for auto reload */
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writel(GPT_FREE_RUNNING, ®s->arr);
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/* start timer */
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setbits_le32(®s->cr1, CR1_CEN);
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/* Update generation */
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setbits_le32(®s->egr, EGR_UG);
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return 0;
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}
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static const struct timer_ops stm32_timer_ops = {
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.get_count = stm32_timer_get_count,
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};
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static const struct udevice_id stm32_timer_ids[] = {
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{ .compatible = "st,stm32-timer" },
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{}
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};
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U_BOOT_DRIVER(stm32_timer) = {
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.name = "stm32_timer",
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.id = UCLASS_TIMER,
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.of_match = stm32_timer_ids,
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.priv_auto = sizeof(struct stm32_timer_priv),
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.probe = stm32_timer_probe,
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.ops = &stm32_timer_ops,
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};
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