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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /drivers/clocksource/h8300_tpu.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/clocksource/h8300_tpu.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/clocksource/h8300_tpu.c b/drivers/clocksource/h8300_tpu.c
new file mode 100644
index 000000000..17d4ab0f6
--- /dev/null
+++ b/drivers/clocksource/h8300_tpu.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * H8S TPU Driver
+ *
+ * Copyright 2015 Yoshinori Sato <ysato@users.sourcefoge.jp>
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/clocksource.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define TCR 0x0
+#define TSR 0x5
+#define TCNT 0x6
+
+#define TCFV 0x10
+
+struct tpu_priv {
+ struct clocksource cs;
+ void __iomem *mapbase1;
+ void __iomem *mapbase2;
+ raw_spinlock_t lock;
+ unsigned int cs_enabled;
+};
+
+static inline unsigned long read_tcnt32(struct tpu_priv *p)
+{
+ unsigned long tcnt;
+
+ tcnt = ioread16be(p->mapbase1 + TCNT) << 16;
+ tcnt |= ioread16be(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 = ioread8(p->mapbase1 + TSR) & TCFV;
+
+ /* 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 = ioread8(p->mapbase1 + TSR) & TCFV;
+ } 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 u64 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);
+
+ iowrite16be(0, p->mapbase1 + TCNT);
+ iowrite16be(0, p->mapbase2 + TCNT);
+ iowrite8(0x0f, p->mapbase1 + TCR);
+ iowrite8(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);
+
+ iowrite8(0, p->mapbase1 + TCR);
+ iowrite8(0, p->mapbase2 + TCR);
+ p->cs_enabled = false;
+}
+
+static struct tpu_priv tpu_priv = {
+ .cs = {
+ .name = "H8S_TPU",
+ .rating = 200,
+ .read = tpu_clocksource_read,
+ .enable = tpu_clocksource_enable,
+ .disable = tpu_clocksource_disable,
+ .mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ },
+};
+
+#define CH_L 0
+#define CH_H 1
+
+static int __init h8300_tpu_init(struct device_node *node)
+{
+ void __iomem *base[2];
+ struct clk *clk;
+ int ret = -ENXIO;
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ pr_err("failed to get clock for clocksource\n");
+ return PTR_ERR(clk);
+ }
+
+ base[CH_L] = of_iomap(node, CH_L);
+ if (!base[CH_L]) {
+ pr_err("failed to map registers for clocksource\n");
+ goto free_clk;
+ }
+ base[CH_H] = of_iomap(node, CH_H);
+ if (!base[CH_H]) {
+ pr_err("failed to map registers for clocksource\n");
+ goto unmap_L;
+ }
+
+ tpu_priv.mapbase1 = base[CH_L];
+ tpu_priv.mapbase2 = base[CH_H];
+
+ return clocksource_register_hz(&tpu_priv.cs, clk_get_rate(clk) / 64);
+
+unmap_L:
+ iounmap(base[CH_H]);
+free_clk:
+ clk_put(clk);
+ return ret;
+}
+
+TIMER_OF_DECLARE(h8300_tpu, "renesas,tpu", h8300_tpu_init);