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sti-timer.c 1.64 KiB
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  • /*
     * (C) Copyright 2017 Patrice Chotard <patrice.chotard@st.com>
     *
     * SPDX-License-Identifier:	GPL-2.0+
     */
    
    #include <common.h>
    #include <dm.h>
    #include <fdtdec.h>
    #include <timer.h>
    
    #include <asm/io.h>
    #include <asm/arch-armv7/globaltimer.h>
    
    DECLARE_GLOBAL_DATA_PTR;
    
    struct sti_timer_priv {
    	struct globaltimer *global_timer;
    };
    
    static int sti_timer_get_count(struct udevice *dev, u64 *count)
    {
    	struct sti_timer_priv *priv = dev_get_priv(dev);
    	struct globaltimer *global_timer = priv->global_timer;
    	u32 low, high;
    	u64 timer;
    	u32 old = readl(&global_timer->cnt_h);
    
    	while (1) {
    		low = readl(&global_timer->cnt_l);
    		high = readl(&global_timer->cnt_h);
    		if (old == high)
    			break;
    		else
    			old = high;
    	}
    	timer = high;
    	*count = (u64)((timer << 32) | low);
    
    	return 0;
    }
    
    static int sti_timer_probe(struct udevice *dev)
    {
    	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
    	struct sti_timer_priv *priv = dev_get_priv(dev);
    	fdt_addr_t addr;
    
    	uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
    
    	/* get arm global timer base address */
    	addr = fdtdec_get_addr(gd->fdt_blob, dev_of_offset(dev), "reg");
    	priv->global_timer = (struct globaltimer *)addr;
    
    	/* init timer */
    	writel(0x01, &priv->global_timer->ctl);
    
    	return 0;
    }
    
    static const struct timer_ops sti_timer_ops = {
    	.get_count = sti_timer_get_count,
    };
    
    static const struct udevice_id sti_timer_ids[] = {
    	{ .compatible = "arm,cortex-a9-global-timer" },
    	{}
    };
    
    U_BOOT_DRIVER(sti_timer) = {
    	.name = "sti_timer",
    	.id = UCLASS_TIMER,
    	.of_match = sti_timer_ids,
    	.priv_auto_alloc_size = sizeof(struct sti_timer_priv),
    	.probe = sti_timer_probe,
    	.ops = &sti_timer_ops,
    	.flags = DM_FLAG_PRE_RELOC,
    };