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![Nicolas Ferre](/assets/img/avatar_default.png)
Some SoC have a 32 bit variant of Timer Counter Blocks. We do not need the chaining of two 16 bit counters anymore for them. The SoC nature is deduced from the device tree "compatible" string. For non-device-tree configurations, backward compatibility is maintained by using the default 16 bit counter configuration. This patch addresses both the atmel_tclib and its user: tcb_clksrc clocksource. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Acked-by: Grant Likely <grant.likely@secretlab.ca>
207 lines
4.5 KiB
C
207 lines
4.5 KiB
C
#include <linux/atmel_tc.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/ioport.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <linux/of.h>
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/*
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* This is a thin library to solve the problem of how to portably allocate
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* one of the TC blocks. For simplicity, it doesn't currently expect to
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* share individual timers between different drivers.
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*/
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#if defined(CONFIG_AVR32)
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/* AVR32 has these divide PBB */
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const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
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EXPORT_SYMBOL(atmel_tc_divisors);
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#elif defined(CONFIG_ARCH_AT91)
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/* AT91 has these divide MCK */
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const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
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EXPORT_SYMBOL(atmel_tc_divisors);
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#endif
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static DEFINE_SPINLOCK(tc_list_lock);
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static LIST_HEAD(tc_list);
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/**
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* atmel_tc_alloc - allocate a specified TC block
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* @block: which block to allocate
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* @name: name to be associated with the iomem resource
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*
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* Caller allocates a block. If it is available, a pointer to a
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* pre-initialized struct atmel_tc is returned. The caller can access
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* the registers directly through the "regs" field.
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*/
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struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
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{
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struct atmel_tc *tc;
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struct platform_device *pdev = NULL;
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struct resource *r;
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size_t size;
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spin_lock(&tc_list_lock);
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list_for_each_entry(tc, &tc_list, node) {
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if (tc->pdev->dev.of_node) {
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if (of_alias_get_id(tc->pdev->dev.of_node, "tcb")
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== block) {
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pdev = tc->pdev;
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break;
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}
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} else if (tc->pdev->id == block) {
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pdev = tc->pdev;
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break;
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}
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}
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if (!pdev || tc->iomem)
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goto fail;
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!r)
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goto fail;
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size = resource_size(r);
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r = request_mem_region(r->start, size, name);
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if (!r)
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goto fail;
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tc->regs = ioremap(r->start, size);
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if (!tc->regs)
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goto fail_ioremap;
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tc->iomem = r;
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out:
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spin_unlock(&tc_list_lock);
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return tc;
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fail_ioremap:
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release_mem_region(r->start, size);
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fail:
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tc = NULL;
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goto out;
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}
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EXPORT_SYMBOL_GPL(atmel_tc_alloc);
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/**
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* atmel_tc_free - release a specified TC block
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* @tc: Timer/counter block that was returned by atmel_tc_alloc()
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*
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* This reverses the effect of atmel_tc_alloc(), unmapping the I/O
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* registers, invalidating the resource returned by that routine and
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* making the TC available to other drivers.
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*/
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void atmel_tc_free(struct atmel_tc *tc)
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{
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spin_lock(&tc_list_lock);
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if (tc->regs) {
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iounmap(tc->regs);
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release_mem_region(tc->iomem->start, resource_size(tc->iomem));
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tc->regs = NULL;
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tc->iomem = NULL;
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}
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spin_unlock(&tc_list_lock);
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}
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EXPORT_SYMBOL_GPL(atmel_tc_free);
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#if defined(CONFIG_OF)
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static struct atmel_tcb_config tcb_rm9200_config = {
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.counter_width = 16,
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};
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static struct atmel_tcb_config tcb_sam9x5_config = {
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.counter_width = 32,
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};
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static const struct of_device_id atmel_tcb_dt_ids[] = {
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{
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.compatible = "atmel,at91rm9200-tcb",
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.data = &tcb_rm9200_config,
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}, {
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.compatible = "atmel,at91sam9x5-tcb",
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.data = &tcb_sam9x5_config,
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}, {
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/* sentinel */
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}
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};
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MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
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#endif
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static int __init tc_probe(struct platform_device *pdev)
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{
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struct atmel_tc *tc;
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struct clk *clk;
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int irq;
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if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
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return -EINVAL;
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irq = platform_get_irq(pdev, 0);
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if (irq < 0)
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return -EINVAL;
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tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
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if (!tc)
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return -ENOMEM;
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tc->pdev = pdev;
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clk = clk_get(&pdev->dev, "t0_clk");
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if (IS_ERR(clk)) {
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kfree(tc);
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return -EINVAL;
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}
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/* Now take SoC information if available */
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if (pdev->dev.of_node) {
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const struct of_device_id *match;
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match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
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if (match)
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tc->tcb_config = match->data;
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}
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tc->clk[0] = clk;
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tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
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if (IS_ERR(tc->clk[1]))
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tc->clk[1] = clk;
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tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
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if (IS_ERR(tc->clk[2]))
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tc->clk[2] = clk;
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tc->irq[0] = irq;
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tc->irq[1] = platform_get_irq(pdev, 1);
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if (tc->irq[1] < 0)
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tc->irq[1] = irq;
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tc->irq[2] = platform_get_irq(pdev, 2);
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if (tc->irq[2] < 0)
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tc->irq[2] = irq;
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spin_lock(&tc_list_lock);
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list_add_tail(&tc->node, &tc_list);
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spin_unlock(&tc_list_lock);
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return 0;
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}
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static struct platform_driver tc_driver = {
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.driver = {
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.name = "atmel_tcb",
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.of_match_table = of_match_ptr(atmel_tcb_dt_ids),
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},
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};
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static int __init tc_init(void)
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{
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return platform_driver_probe(&tc_driver, tc_probe);
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}
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arch_initcall(tc_init);
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