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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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4.5 kB · 207 lines
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208// SPDX-License-Identifier: GPL-2.0+//// Copyright 2017-2019 NXP
#include <linux/interrupt.h>#include <linux/clockchips.h>#include <linux/slab.h>
#include "timer-of.h"
#define CMP_OFFSET 0x10000#define RD_OFFSET 0x20000
#define CNTCV_LO 0x8#define CNTCV_HI 0xc#define CMPCV_LO (CMP_OFFSET + 0x20)#define CMPCV_HI (CMP_OFFSET + 0x24)#define CMPCR (CMP_OFFSET + 0x2c)#define CNTCV_LO_IMX95 (RD_OFFSET + 0x8)#define CNTCV_HI_IMX95 (RD_OFFSET + 0xc)
#define SYS_CTR_EN 0x1#define SYS_CTR_IRQ_MASK 0x2
#define SYS_CTR_CLK_DIV 0x3
struct sysctr_private { u32 cmpcr; u32 lo_off; u32 hi_off;};
static void sysctr_timer_enable(struct clock_event_device *evt, bool enable){ struct timer_of *to = to_timer_of(evt); struct sysctr_private *priv = to->private_data; void __iomem *base = timer_of_base(to);
writel(enable ? priv->cmpcr | SYS_CTR_EN : priv->cmpcr, base + CMPCR);}
static void sysctr_irq_acknowledge(struct clock_event_device *evt){ /* * clear the enable bit(EN =0) will clear * the status bit(ISTAT = 0), then the interrupt * signal will be negated(acknowledged). */ sysctr_timer_enable(evt, false);}
static inline u64 sysctr_read_counter(struct clock_event_device *evt){ struct timer_of *to = to_timer_of(evt); struct sysctr_private *priv = to->private_data; void __iomem *base = timer_of_base(to); u32 cnt_hi, tmp_hi, cnt_lo;
do { cnt_hi = readl_relaxed(base + priv->hi_off); cnt_lo = readl_relaxed(base + priv->lo_off); tmp_hi = readl_relaxed(base + priv->hi_off); } while (tmp_hi != cnt_hi);
return ((u64) cnt_hi << 32) | cnt_lo;}
static int sysctr_set_next_event(unsigned long delta, struct clock_event_device *evt){ struct timer_of *to = to_timer_of(evt); void __iomem *base = timer_of_base(to); u32 cmp_hi, cmp_lo; u64 next;
sysctr_timer_enable(evt, false);
next = sysctr_read_counter(evt);
next += delta;
cmp_hi = (next >> 32) & 0x00fffff; cmp_lo = next & 0xffffffff;
writel_relaxed(cmp_hi, base + CMPCV_HI); writel_relaxed(cmp_lo, base + CMPCV_LO);
sysctr_timer_enable(evt, true);
return 0;}
static int sysctr_set_state_oneshot(struct clock_event_device *evt){ return 0;}
static int sysctr_set_state_shutdown(struct clock_event_device *evt){ sysctr_timer_enable(evt, false);
return 0;}
static irqreturn_t sysctr_timer_interrupt(int irq, void *dev_id){ struct clock_event_device *evt = dev_id;
sysctr_irq_acknowledge(evt);
evt->event_handler(evt);
return IRQ_HANDLED;}
static struct timer_of to_sysctr = { .flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE, .clkevt = { .name = "i.MX system counter timer", .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ, .set_state_oneshot = sysctr_set_state_oneshot, .set_next_event = sysctr_set_next_event, .set_state_shutdown = sysctr_set_state_shutdown, .rating = 200, }, .of_irq = { .handler = sysctr_timer_interrupt, .flags = IRQF_TIMER, }, .of_clk = { .name = "per", },};
static int __init __sysctr_timer_init(struct device_node *np){ struct sysctr_private *priv; void __iomem *base; int ret;
priv = kzalloc_obj(struct sysctr_private); if (!priv) return -ENOMEM;
ret = timer_of_init(np, &to_sysctr); if (ret) { kfree(priv); return ret; }
if (!of_property_read_bool(np, "nxp,no-divider")) { /* system counter clock is divided by 3 internally */ to_sysctr.of_clk.rate /= SYS_CTR_CLK_DIV; }
to_sysctr.clkevt.cpumask = cpu_possible_mask; to_sysctr.private_data = priv;
base = timer_of_base(&to_sysctr); priv->cmpcr = readl(base + CMPCR) & ~SYS_CTR_EN;
return 0;}
static int __init sysctr_timer_init(struct device_node *np){ struct sysctr_private *priv; int ret;
ret = __sysctr_timer_init(np); if (ret) return ret;
priv = to_sysctr.private_data; priv->lo_off = CNTCV_LO; priv->hi_off = CNTCV_HI;
clockevents_config_and_register(&to_sysctr.clkevt, timer_of_rate(&to_sysctr), 0xff, 0x7fffffff);
return 0;}
static int __init sysctr_timer_imx95_init(struct device_node *np){ struct sysctr_private *priv; int ret;
ret = __sysctr_timer_init(np); if (ret) return ret;
priv = to_sysctr.private_data; priv->lo_off = CNTCV_LO_IMX95; priv->hi_off = CNTCV_HI_IMX95;
clockevents_config_and_register(&to_sysctr.clkevt, timer_of_rate(&to_sysctr), 0xff, 0x7fffffff);
return 0;}
TIMER_OF_DECLARE(sysctr_timer, "nxp,sysctr-timer", sysctr_timer_init);TIMER_OF_DECLARE(sysctr_timer_imx95, "nxp,imx95-sysctr-timer", sysctr_timer_imx95_init);