Skip to content
Snippets Groups Projects
omap-timer.c 2.75 KiB
Newer Older
  • Learn to ignore specific revisions
  • /*
     * TI OMAP timer driver
     *
     * Copyright (C) 2015, Texas Instruments, Incorporated
     *
     * SPDX-License-Identifier: GPL-2.0+
     */
    
    #include <common.h>
    #include <dm.h>
    #include <errno.h>
    #include <timer.h>
    #include <asm/io.h>
    #include <asm/arch/clock.h>
    
    DECLARE_GLOBAL_DATA_PTR;
    
    /* Timer register bits */
    #define TCLR_START			BIT(0)	/* Start=1 */
    #define TCLR_AUTO_RELOAD		BIT(1)	/* Auto reload */
    #define TCLR_PRE_EN			BIT(5)	/* Pre-scaler enable */
    #define TCLR_PTV_SHIFT			(2)	/* Pre-scaler shift value */
    
    #define TIMER_CLOCK             (V_SCLK / (2 << CONFIG_SYS_PTV))
    
    struct omap_gptimer_regs {
    	unsigned int tidr;		/* offset 0x00 */
    	unsigned char res1[12];
    	unsigned int tiocp_cfg;		/* offset 0x10 */
    	unsigned char res2[12];
    	unsigned int tier;		/* offset 0x20 */
    	unsigned int tistatr;		/* offset 0x24 */
    	unsigned int tistat;		/* offset 0x28 */
    	unsigned int tisr;		/* offset 0x2c */
    	unsigned int tcicr;		/* offset 0x30 */
    	unsigned int twer;		/* offset 0x34 */
    	unsigned int tclr;		/* offset 0x38 */
    	unsigned int tcrr;		/* offset 0x3c */
    	unsigned int tldr;		/* offset 0x40 */
    	unsigned int ttgr;		/* offset 0x44 */
    	unsigned int twpc;		/* offset 0x48 */
    	unsigned int tmar;		/* offset 0x4c */
    	unsigned int tcar1;		/* offset 0x50 */
    	unsigned int tscir;		/* offset 0x54 */
    	unsigned int tcar2;		/* offset 0x58 */
    };
    
    /* Omap Timer Priv */
    struct omap_timer_priv {
    	struct omap_gptimer_regs *regs;
    };
    
    static int omap_timer_get_count(struct udevice *dev, u64 *count)
    {
    	struct omap_timer_priv *priv = dev_get_priv(dev);
    
    	*count = readl(&priv->regs->tcrr);
    
    	return 0;
    }
    
    static int omap_timer_probe(struct udevice *dev)
    {
    	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
    	struct omap_timer_priv *priv = dev_get_priv(dev);
    
    	uc_priv->clock_rate = TIMER_CLOCK;
    
    	/* start the counter ticking up, reload value on overflow */
    	writel(0, &priv->regs->tldr);
    	/* enable timer */
    	writel((CONFIG_SYS_PTV << 2) | TCLR_PRE_EN | TCLR_AUTO_RELOAD |
    	       TCLR_START, &priv->regs->tclr);
    
    	return 0;
    }
    
    static int omap_timer_ofdata_to_platdata(struct udevice *dev)
    {
    	struct omap_timer_priv *priv = dev_get_priv(dev);
    
    
    	priv->regs = map_physmem(dev_get_addr(dev),
    				 sizeof(struct omap_gptimer_regs), MAP_NOCACHE);
    
    
    	return 0;
    }
    
    
    static const struct timer_ops omap_timer_ops = {
    	.get_count = omap_timer_get_count,
    };
    
    static const struct udevice_id omap_timer_ids[] = {
    	{ .compatible = "ti,am335x-timer" },
    	{ .compatible = "ti,am4372-timer" },
    	{ .compatible = "ti,omap5430-timer" },
    	{}
    };
    
    U_BOOT_DRIVER(omap_timer) = {
    	.name	= "omap_timer",
    	.id	= UCLASS_TIMER,
    	.of_match = omap_timer_ids,
    	.ofdata_to_platdata = omap_timer_ofdata_to_platdata,
    	.priv_auto_alloc_size = sizeof(struct omap_timer_priv),
    	.probe = omap_timer_probe,
    	.ops	= &omap_timer_ops,
    	.flags = DM_FLAG_PRE_RELOC,
    };