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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 /arch/mips/ralink/timer.c
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.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--arch/mips/ralink/timer.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/mips/ralink/timer.c b/arch/mips/ralink/timer.c
new file mode 100644
index 000000000..652424d8e
--- /dev/null
+++ b/arch/mips/ralink/timer.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ralink RT2880 timer
+ * Author: John Crispin
+ *
+ * Copyright (C) 2013 John Crispin <john@phrozen.org>
+*/
+
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/timer.h>
+#include <linux/of_gpio.h>
+#include <linux/clk.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define TIMER_REG_TMRSTAT 0x00
+#define TIMER_REG_TMR0LOAD 0x10
+#define TIMER_REG_TMR0CTL 0x18
+
+#define TMRSTAT_TMR0INT BIT(0)
+
+#define TMR0CTL_ENABLE BIT(7)
+#define TMR0CTL_MODE_PERIODIC BIT(4)
+#define TMR0CTL_PRESCALER 1
+#define TMR0CTL_PRESCALE_VAL (0xf - TMR0CTL_PRESCALER)
+#define TMR0CTL_PRESCALE_DIV (65536 / BIT(TMR0CTL_PRESCALER))
+
+struct rt_timer {
+ struct device *dev;
+ void __iomem *membase;
+ int irq;
+ unsigned long timer_freq;
+ unsigned long timer_div;
+};
+
+static inline void rt_timer_w32(struct rt_timer *rt, u8 reg, u32 val)
+{
+ __raw_writel(val, rt->membase + reg);
+}
+
+static inline u32 rt_timer_r32(struct rt_timer *rt, u8 reg)
+{
+ return __raw_readl(rt->membase + reg);
+}
+
+static irqreturn_t rt_timer_irq(int irq, void *_rt)
+{
+ struct rt_timer *rt = (struct rt_timer *) _rt;
+
+ rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
+ rt_timer_w32(rt, TIMER_REG_TMRSTAT, TMRSTAT_TMR0INT);
+
+ return IRQ_HANDLED;
+}
+
+
+static int rt_timer_request(struct rt_timer *rt)
+{
+ int err = request_irq(rt->irq, rt_timer_irq, 0,
+ dev_name(rt->dev), rt);
+ if (err) {
+ dev_err(rt->dev, "failed to request irq\n");
+ } else {
+ u32 t = TMR0CTL_MODE_PERIODIC | TMR0CTL_PRESCALE_VAL;
+ rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
+ }
+ return err;
+}
+
+static int rt_timer_config(struct rt_timer *rt, unsigned long divisor)
+{
+ if (rt->timer_freq < divisor)
+ rt->timer_div = rt->timer_freq;
+ else
+ rt->timer_div = divisor;
+
+ rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
+
+ return 0;
+}
+
+static int rt_timer_enable(struct rt_timer *rt)
+{
+ u32 t;
+
+ rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
+
+ t = rt_timer_r32(rt, TIMER_REG_TMR0CTL);
+ t |= TMR0CTL_ENABLE;
+ rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
+
+ return 0;
+}
+
+static int rt_timer_probe(struct platform_device *pdev)
+{
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ struct rt_timer *rt;
+ struct clk *clk;
+
+ rt = devm_kzalloc(&pdev->dev, sizeof(*rt), GFP_KERNEL);
+ if (!rt) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ rt->irq = platform_get_irq(pdev, 0);
+ if (rt->irq < 0)
+ return rt->irq;
+
+ rt->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(rt->membase))
+ return PTR_ERR(rt->membase);
+
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "failed get clock rate\n");
+ return PTR_ERR(clk);
+ }
+
+ rt->timer_freq = clk_get_rate(clk) / TMR0CTL_PRESCALE_DIV;
+ if (!rt->timer_freq)
+ return -EINVAL;
+
+ rt->dev = &pdev->dev;
+ platform_set_drvdata(pdev, rt);
+
+ rt_timer_request(rt);
+ rt_timer_config(rt, 2);
+ rt_timer_enable(rt);
+
+ dev_info(&pdev->dev, "maximum frequency is %luHz\n", rt->timer_freq);
+
+ return 0;
+}
+
+static const struct of_device_id rt_timer_match[] = {
+ { .compatible = "ralink,rt2880-timer" },
+ {},
+};
+
+static struct platform_driver rt_timer_driver = {
+ .probe = rt_timer_probe,
+ .driver = {
+ .name = "rt-timer",
+ .of_match_table = rt_timer_match,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(rt_timer_driver);