--- /dev/null
+/*
+ * H8/300 TPU Driver
+ *
+ * Copyright 2015 Yoshinori Sato <ysato@users.sourcefoge.jp>
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/clocksource.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include <asm/irq.h>
+
+#define TCR 0
+#define TMDR 1
+#define TIOR 2
+#define TER 4
+#define TSR 5
+#define TCNT 6
+#define TGRA 8
+#define TGRB 10
+#define TGRC 12
+#define TGRD 14
+
+struct tpu_priv {
+ struct platform_device *pdev;
+ struct clocksource cs;
+ struct clk *clk;
+ unsigned long mapbase1;
+ unsigned long mapbase2;
+ raw_spinlock_t lock;
+ unsigned int cs_enabled;
+};
+
+static inline unsigned long read_tcnt32(struct tpu_priv *p)
+{
+ unsigned long tcnt;
+
+ tcnt = ctrl_inw(p->mapbase1 + TCNT) << 16;
+ tcnt |= ctrl_inw(p->mapbase2 + TCNT);
+ return tcnt;
+}
+
+static int tpu_get_counter(struct tpu_priv *p, unsigned long long *val)
+{
+ unsigned long v1, v2, v3;
+ int o1, o2;
+
+ o1 = ctrl_inb(p->mapbase1 + TSR) & 0x10;
+
+ /* Make sure the timer value is stable. Stolen from acpi_pm.c */
+ do {
+ o2 = o1;
+ v1 = read_tcnt32(p);
+ v2 = read_tcnt32(p);
+ v3 = read_tcnt32(p);
+ o1 = ctrl_inb(p->mapbase1 + TSR) & 0x10;
+ } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
+ || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
+
+ *val = v2;
+ return o1;
+}
+
+static inline struct tpu_priv *cs_to_priv(struct clocksource *cs)
+{
+ return container_of(cs, struct tpu_priv, cs);
+}
+
+static cycle_t tpu_clocksource_read(struct clocksource *cs)
+{
+ struct tpu_priv *p = cs_to_priv(cs);
+ unsigned long flags;
+ unsigned long long value;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+ if (tpu_get_counter(p, &value))
+ value += 0x100000000;
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return value;
+}
+
+static int tpu_clocksource_enable(struct clocksource *cs)
+{
+ struct tpu_priv *p = cs_to_priv(cs);
+
+ WARN_ON(p->cs_enabled);
+
+ ctrl_outw(0, p->mapbase1 + TCNT);
+ ctrl_outw(0, p->mapbase2 + TCNT);
+ ctrl_outb(0x0f, p->mapbase1 + TCR);
+ ctrl_outb(0x03, p->mapbase2 + TCR);
+
+ p->cs_enabled = true;
+ return 0;
+}
+
+static void tpu_clocksource_disable(struct clocksource *cs)
+{
+ struct tpu_priv *p = cs_to_priv(cs);
+
+ WARN_ON(!p->cs_enabled);
+
+ ctrl_outb(0, p->mapbase1 + TCR);
+ ctrl_outb(0, p->mapbase2 + TCR);
+ p->cs_enabled = false;
+}
+
+#define CH_L 0
+#define CH_H 1
+
+static int __init tpu_setup(struct tpu_priv *p, struct platform_device *pdev)
+{
+ struct resource *res[2];
+
+ p->pdev = pdev;
+
+ res[CH_L] = platform_get_resource(p->pdev, IORESOURCE_MEM, CH_L);
+ res[CH_H] = platform_get_resource(p->pdev, IORESOURCE_MEM, CH_H);
+ if (!res[CH_L] || !res[CH_H]) {
+ dev_err(&p->pdev->dev, "failed to get I/O memory\n");
+ return -ENXIO;
+ }
+
+ p->clk = clk_get(&p->pdev->dev, "fck");
+ if (IS_ERR(p->clk)) {
+ dev_err(&p->pdev->dev, "can't get clk\n");
+ return PTR_ERR(p->clk);
+ }
+
+ p->mapbase1 = res[CH_L]->start;
+ p->mapbase2 = res[CH_H]->start;
+
+ p->cs.name = pdev->name;
+ p->cs.rating = 200;
+ p->cs.read = tpu_clocksource_read;
+ p->cs.enable = tpu_clocksource_enable;
+ p->cs.disable = tpu_clocksource_disable;
+ p->cs.mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
+ p->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+ clocksource_register_hz(&p->cs, clk_get_rate(p->clk) / 64);
+ platform_set_drvdata(pdev, p);
+
+ return 0;
+}
+
+static int tpu_probe(struct platform_device *pdev)
+{
+ struct tpu_priv *p = platform_get_drvdata(pdev);
+
+ if (p) {
+ dev_info(&pdev->dev, "kept as earlytimer\n");
+ return 0;
+ }
+
+ p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ return tpu_setup(p, pdev);
+}
+
+static int tpu_remove(struct platform_device *pdev)
+{
+ return -EBUSY;
+}
+
+static const struct of_device_id tpu_of_table[] = {
+ { .compatible = "renesas,tpu" },
+ { }
+};
+
+static struct platform_driver tpu_driver = {
+ .probe = tpu_probe,
+ .remove = tpu_remove,
+ .driver = {
+ .name = "h8s-tpu",
+ .of_match_table = of_match_ptr(tpu_of_table),
+ }
+};
+
+static int __init tpu_init(void)
+{
+ return platform_driver_register(&tpu_driver);
+}
+
+static void __exit tpu_exit(void)
+{
+ platform_driver_unregister(&tpu_driver);
+}
+
+subsys_initcall(tpu_init);
+module_exit(tpu_exit);
+MODULE_AUTHOR("Yoshinori Sato");
+MODULE_DESCRIPTION("H8S Timer Pulse Unit Driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff