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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/mips/ralink/timer.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/mips/ralink/timer.c | 151 |
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); |