atmel_tclib.c

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#include <linux/atmel_tc.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/of.h>

/*
 * This is a thin library to solve the problem of how to portably allocate
 * one of the TC blocks.  For simplicity, it doesn't currently expect to
 * share individual timers between different drivers.
 */

#if defined(CONFIG_AVR32)
/* AVR32 has these divide PBB */
const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
EXPORT_SYMBOL(atmel_tc_divisors);

#elif defined(CONFIG_ARCH_AT91)
/* AT91 has these divide MCK */
const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
EXPORT_SYMBOL(atmel_tc_divisors);

#endif

static DEFINE_SPINLOCK(tc_list_lock);
static LIST_HEAD(tc_list);

struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
{
    struct atmel_tc     *tc;
    struct platform_device  *pdev = NULL;
    struct resource     *r;
    size_t          size;

    spin_lock(&tc_list_lock);
    list_for_each_entry(tc, &tc_list, node) {
        if (tc->pdev->dev.of_node) {
            if (of_alias_get_id(tc->pdev->dev.of_node, "tcb")
                    == block) {
                pdev = tc->pdev;
                break;
            }
        } else if (tc->pdev->id == block) {
            pdev = tc->pdev;
            break;
        }
    }

    if (!pdev || tc->iomem)
        goto fail;

    r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!r)
        goto fail;

    size = resource_size(r);
    r = request_mem_region(r->start, size, name);
    if (!r)
        goto fail;

    tc->regs = ioremap(r->start, size);
    if (!tc->regs)
        goto fail_ioremap;

    tc->iomem = r;

out:
    spin_unlock(&tc_list_lock);
    return tc;

fail_ioremap:
    release_mem_region(r->start, size);
fail:
    tc = NULL;
    goto out;
}
EXPORT_SYMBOL_GPL(atmel_tc_alloc);

void atmel_tc_free(struct atmel_tc *tc)
{
    spin_lock(&tc_list_lock);
    if (tc->regs) {
        iounmap(tc->regs);
        release_mem_region(tc->iomem->start, resource_size(tc->iomem));
        tc->regs = NULL;
        tc->iomem = NULL;
    }
    spin_unlock(&tc_list_lock);
}
EXPORT_SYMBOL_GPL(atmel_tc_free);

#if defined(CONFIG_OF)
static struct atmel_tcb_config tcb_rm9200_config = {
    .counter_width = 16,
};

static struct atmel_tcb_config tcb_sam9x5_config = {
    .counter_width = 32,
};

static const struct of_device_id atmel_tcb_dt_ids[] = {
    {
        .compatible = "atmel,at91rm9200-tcb",
        .data = &tcb_rm9200_config,
    }, {
        .compatible = "atmel,at91sam9x5-tcb",
        .data = &tcb_sam9x5_config,
    }, {
        /* sentinel */
    }
};

MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
#endif

static int __init tc_probe(struct platform_device *pdev)
{
    struct atmel_tc *tc;
    struct clk  *clk;
    int     irq;

    if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
        return -EINVAL;

    irq = platform_get_irq(pdev, 0);
    if (irq < 0)
        return -EINVAL;

    tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
    if (!tc)
        return -ENOMEM;

    tc->pdev = pdev;

    clk = clk_get(&pdev->dev, "t0_clk");
    if (IS_ERR(clk)) {
        kfree(tc);
        return -EINVAL;
    }

    /* Now take SoC information if available */
    if (pdev->dev.of_node) {
        const struct of_device_id *match;
        match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
        if (match)
            tc->tcb_config = match->data;
    }

    tc->clk[0] = clk;
    tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
    if (IS_ERR(tc->clk[1]))
        tc->clk[1] = clk;
    tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
    if (IS_ERR(tc->clk[2]))
        tc->clk[2] = clk;

    tc->irq[0] = irq;
    tc->irq[1] = platform_get_irq(pdev, 1);
    if (tc->irq[1] < 0)
        tc->irq[1] = irq;
    tc->irq[2] = platform_get_irq(pdev, 2);
    if (tc->irq[2] < 0)
        tc->irq[2] = irq;

    spin_lock(&tc_list_lock);
    list_add_tail(&tc->node, &tc_list);
    spin_unlock(&tc_list_lock);

    return 0;
}

static struct platform_driver tc_driver = {
    .driver = {
        .name   = "atmel_tcb",
        .of_match_table = of_match_ptr(atmel_tcb_dt_ids),
    },
};

static int __init tc_init(void)
{
    return platform_driver_probe(&tc_driver, tc_probe);
}
arch_initcall(tc_init);