1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Cirrus Logic CLPS711X clocksource driver
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/clk.h>
9*4882a593Smuzhiyun #include <linux/clockchips.h>
10*4882a593Smuzhiyun #include <linux/clocksource.h>
11*4882a593Smuzhiyun #include <linux/interrupt.h>
12*4882a593Smuzhiyun #include <linux/io.h>
13*4882a593Smuzhiyun #include <linux/of_address.h>
14*4882a593Smuzhiyun #include <linux/of_irq.h>
15*4882a593Smuzhiyun #include <linux/sched_clock.h>
16*4882a593Smuzhiyun #include <linux/slab.h>
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun enum {
19*4882a593Smuzhiyun CLPS711X_CLKSRC_CLOCKSOURCE,
20*4882a593Smuzhiyun CLPS711X_CLKSRC_CLOCKEVENT,
21*4882a593Smuzhiyun };
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun static void __iomem *tcd;
24*4882a593Smuzhiyun
clps711x_sched_clock_read(void)25*4882a593Smuzhiyun static u64 notrace clps711x_sched_clock_read(void)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun return ~readw(tcd);
28*4882a593Smuzhiyun }
29*4882a593Smuzhiyun
clps711x_clksrc_init(struct clk * clock,void __iomem * base)30*4882a593Smuzhiyun static void __init clps711x_clksrc_init(struct clk *clock, void __iomem *base)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun unsigned long rate = clk_get_rate(clock);
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun tcd = base;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16,
37*4882a593Smuzhiyun clocksource_mmio_readw_down);
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun sched_clock_register(clps711x_sched_clock_read, 16, rate);
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun
clps711x_timer_interrupt(int irq,void * dev_id)42*4882a593Smuzhiyun static irqreturn_t clps711x_timer_interrupt(int irq, void *dev_id)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun struct clock_event_device *evt = dev_id;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun evt->event_handler(evt);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun return IRQ_HANDLED;
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
_clps711x_clkevt_init(struct clk * clock,void __iomem * base,unsigned int irq)51*4882a593Smuzhiyun static int __init _clps711x_clkevt_init(struct clk *clock, void __iomem *base,
52*4882a593Smuzhiyun unsigned int irq)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun struct clock_event_device *clkevt;
55*4882a593Smuzhiyun unsigned long rate;
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
58*4882a593Smuzhiyun if (!clkevt)
59*4882a593Smuzhiyun return -ENOMEM;
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun rate = clk_get_rate(clock);
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun /* Set Timer prescaler */
64*4882a593Smuzhiyun writew(DIV_ROUND_CLOSEST(rate, HZ), base);
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun clkevt->name = "clps711x-clockevent";
67*4882a593Smuzhiyun clkevt->rating = 300;
68*4882a593Smuzhiyun clkevt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_C3STOP;
69*4882a593Smuzhiyun clkevt->cpumask = cpumask_of(0);
70*4882a593Smuzhiyun clockevents_config_and_register(clkevt, HZ, 0, 0);
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER,
73*4882a593Smuzhiyun "clps711x-timer", clkevt);
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun
clps711x_timer_init(struct device_node * np)76*4882a593Smuzhiyun static int __init clps711x_timer_init(struct device_node *np)
77*4882a593Smuzhiyun {
78*4882a593Smuzhiyun unsigned int irq = irq_of_parse_and_map(np, 0);
79*4882a593Smuzhiyun struct clk *clock = of_clk_get(np, 0);
80*4882a593Smuzhiyun void __iomem *base = of_iomap(np, 0);
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun if (!base)
83*4882a593Smuzhiyun return -ENOMEM;
84*4882a593Smuzhiyun if (!irq)
85*4882a593Smuzhiyun return -EINVAL;
86*4882a593Smuzhiyun if (IS_ERR(clock))
87*4882a593Smuzhiyun return PTR_ERR(clock);
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun switch (of_alias_get_id(np, "timer")) {
90*4882a593Smuzhiyun case CLPS711X_CLKSRC_CLOCKSOURCE:
91*4882a593Smuzhiyun clps711x_clksrc_init(clock, base);
92*4882a593Smuzhiyun break;
93*4882a593Smuzhiyun case CLPS711X_CLKSRC_CLOCKEVENT:
94*4882a593Smuzhiyun return _clps711x_clkevt_init(clock, base, irq);
95*4882a593Smuzhiyun default:
96*4882a593Smuzhiyun return -EINVAL;
97*4882a593Smuzhiyun }
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun return 0;
100*4882a593Smuzhiyun }
101*4882a593Smuzhiyun TIMER_OF_DECLARE(clps711x, "cirrus,ep7209-timer", clps711x_timer_init);
102