diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/clocksource/h8300_tpu.c | |
parent | Initial commit. (diff) | |
download | linux-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.c | 158 |
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); |