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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/misc/atmel_tclib.c
Initial import
Diffstat (limited to 'drivers/misc/atmel_tclib.c')
-rw-r--r--drivers/misc/atmel_tclib.c194
1 files changed, 194 insertions, 0 deletions
diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c
new file mode 100644
index 000000000..0ca05c3ec
--- /dev/null
+++ b/drivers/misc/atmel_tclib.c
@@ -0,0 +1,194 @@
+#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);
+
+/**
+ * atmel_tc_alloc - allocate a specified TC block
+ * @block: which block to allocate
+ *
+ * Caller allocates a block. If it is available, a pointer to a
+ * pre-initialized struct atmel_tc is returned. The caller can access
+ * the registers directly through the "regs" field.
+ */
+struct atmel_tc *atmel_tc_alloc(unsigned block)
+{
+ struct atmel_tc *tc;
+ struct platform_device *pdev = NULL;
+
+ spin_lock(&tc_list_lock);
+ list_for_each_entry(tc, &tc_list, node) {
+ if (tc->allocated)
+ continue;
+
+ if ((tc->pdev->dev.of_node && tc->id == block) ||
+ (tc->pdev->id == block)) {
+ pdev = tc->pdev;
+ tc->allocated = true;
+ break;
+ }
+ }
+ spin_unlock(&tc_list_lock);
+
+ return pdev ? tc : NULL;
+}
+EXPORT_SYMBOL_GPL(atmel_tc_alloc);
+
+/**
+ * atmel_tc_free - release a specified TC block
+ * @tc: Timer/counter block that was returned by atmel_tc_alloc()
+ *
+ * This reverses the effect of atmel_tc_alloc(), invalidating the resource
+ * returned by that routine and making the TC available to other drivers.
+ */
+void atmel_tc_free(struct atmel_tc *tc)
+{
+ spin_lock(&tc_list_lock);
+ if (tc->allocated)
+ tc->allocated = false;
+ 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;
+ struct resource *r;
+ unsigned int i;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return -EINVAL;
+
+ tc = devm_kzalloc(&pdev->dev, sizeof(struct atmel_tc), GFP_KERNEL);
+ if (!tc)
+ return -ENOMEM;
+
+ tc->pdev = pdev;
+
+ clk = devm_clk_get(&pdev->dev, "t0_clk");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ tc->regs = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(tc->regs))
+ return PTR_ERR(tc->regs);
+
+ /* 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->id = of_alias_get_id(tc->pdev->dev.of_node, "tcb");
+ } else {
+ tc->id = pdev->id;
+ }
+
+ tc->clk[0] = clk;
+ tc->clk[1] = devm_clk_get(&pdev->dev, "t1_clk");
+ if (IS_ERR(tc->clk[1]))
+ tc->clk[1] = clk;
+ tc->clk[2] = devm_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;
+
+ for (i = 0; i < 3; i++)
+ writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
+
+ spin_lock(&tc_list_lock);
+ list_add_tail(&tc->node, &tc_list);
+ spin_unlock(&tc_list_lock);
+
+ platform_set_drvdata(pdev, tc);
+
+ return 0;
+}
+
+static void tc_shutdown(struct platform_device *pdev)
+{
+ int i;
+ struct atmel_tc *tc = platform_get_drvdata(pdev);
+
+ for (i = 0; i < 3; i++)
+ writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
+}
+
+static struct platform_driver tc_driver = {
+ .driver = {
+ .name = "atmel_tcb",
+ .of_match_table = of_match_ptr(atmel_tcb_dt_ids),
+ },
+ .shutdown = tc_shutdown,
+};
+
+static int __init tc_init(void)
+{
+ return platform_driver_probe(&tc_driver, tc_probe);
+}
+arch_initcall(tc_init);