1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2018 Socionext Inc.
  4 */
  5
  6#include <linux/clk.h>
  7#include <linux/interrupt.h>
  8#include <linux/irq.h>
  9#include <linux/irqreturn.h>
 10#include <linux/sched_clock.h>
 11#include "timer-of.h"
 12
 13#define MLB_TMR_TMCSR_OFS	0x0
 14#define MLB_TMR_TMR_OFS		0x4
 15#define MLB_TMR_TMRLR1_OFS	0x8
 16#define MLB_TMR_TMRLR2_OFS	0xc
 17#define MLB_TMR_REGSZPCH	0x10
 18
 19#define MLB_TMR_TMCSR_OUTL	BIT(5)
 20#define MLB_TMR_TMCSR_RELD	BIT(4)
 21#define MLB_TMR_TMCSR_INTE	BIT(3)
 22#define MLB_TMR_TMCSR_UF	BIT(2)
 23#define MLB_TMR_TMCSR_CNTE	BIT(1)
 24#define MLB_TMR_TMCSR_TRG	BIT(0)
 25
 26#define MLB_TMR_TMCSR_CSL_DIV2	0
 27#define MLB_TMR_DIV_CNT		2
 28
 29#define MLB_TMR_SRC_CH		1
 30#define MLB_TMR_EVT_CH		0
 31
 32#define MLB_TMR_SRC_CH_OFS	(MLB_TMR_REGSZPCH * MLB_TMR_SRC_CH)
 33#define MLB_TMR_EVT_CH_OFS	(MLB_TMR_REGSZPCH * MLB_TMR_EVT_CH)
 34
 35#define MLB_TMR_SRC_TMCSR_OFS	(MLB_TMR_SRC_CH_OFS + MLB_TMR_TMCSR_OFS)
 36#define MLB_TMR_SRC_TMR_OFS	(MLB_TMR_SRC_CH_OFS + MLB_TMR_TMR_OFS)
 37#define MLB_TMR_SRC_TMRLR1_OFS	(MLB_TMR_SRC_CH_OFS + MLB_TMR_TMRLR1_OFS)
 38#define MLB_TMR_SRC_TMRLR2_OFS	(MLB_TMR_SRC_CH_OFS + MLB_TMR_TMRLR2_OFS)
 39
 40#define MLB_TMR_EVT_TMCSR_OFS	(MLB_TMR_EVT_CH_OFS + MLB_TMR_TMCSR_OFS)
 41#define MLB_TMR_EVT_TMR_OFS	(MLB_TMR_EVT_CH_OFS + MLB_TMR_TMR_OFS)
 42#define MLB_TMR_EVT_TMRLR1_OFS	(MLB_TMR_EVT_CH_OFS + MLB_TMR_TMRLR1_OFS)
 43#define MLB_TMR_EVT_TMRLR2_OFS	(MLB_TMR_EVT_CH_OFS + MLB_TMR_TMRLR2_OFS)
 44
 45#define MLB_TIMER_RATING	500
 46#define MLB_TIMER_ONESHOT	0
 47#define MLB_TIMER_PERIODIC	1
 48
 49static irqreturn_t mlb_timer_interrupt(int irq, void *dev_id)
 50{
 51	struct clock_event_device *clk = dev_id;
 52	struct timer_of *to = to_timer_of(clk);
 53	u32 val;
 54
 55	val = readl_relaxed(timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
 56	val &= ~MLB_TMR_TMCSR_UF;
 57	writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
 58
 59	clk->event_handler(clk);
 60
 61	return IRQ_HANDLED;
 62}
 63
 64static void mlb_evt_timer_start(struct timer_of *to, bool periodic)
 65{
 66	u32 val = MLB_TMR_TMCSR_CSL_DIV2;
 67
 68	val |= MLB_TMR_TMCSR_CNTE | MLB_TMR_TMCSR_TRG | MLB_TMR_TMCSR_INTE;
 69	if (periodic)
 70		val |= MLB_TMR_TMCSR_RELD;
 71	writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
 72}
 73
 74static void mlb_evt_timer_stop(struct timer_of *to)
 75{
 76	u32 val = readl_relaxed(timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
 77
 78	val &= ~MLB_TMR_TMCSR_CNTE;
 79	writel_relaxed(val, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
 80}
 81
 82static void mlb_evt_timer_register_count(struct timer_of *to, unsigned long cnt)
 83{
 84	writel_relaxed(cnt, timer_of_base(to) + MLB_TMR_EVT_TMRLR1_OFS);
 85}
 86
 87static int mlb_set_state_periodic(struct clock_event_device *clk)
 88{
 89	struct timer_of *to = to_timer_of(clk);
 90
 91	mlb_evt_timer_stop(to);
 92	mlb_evt_timer_register_count(to, to->of_clk.period);
 93	mlb_evt_timer_start(to, MLB_TIMER_PERIODIC);
 94	return 0;
 95}
 96
 97static int mlb_set_state_oneshot(struct clock_event_device *clk)
 98{
 99	struct timer_of *to = to_timer_of(clk);
100
101	mlb_evt_timer_stop(to);
102	mlb_evt_timer_start(to, MLB_TIMER_ONESHOT);
103	return 0;
104}
105
106static int mlb_set_state_shutdown(struct clock_event_device *clk)
107{
108	struct timer_of *to = to_timer_of(clk);
109
110	mlb_evt_timer_stop(to);
111	return 0;
112}
113
114static int mlb_clkevt_next_event(unsigned long event,
115				   struct clock_event_device *clk)
116{
117	struct timer_of *to = to_timer_of(clk);
118
119	mlb_evt_timer_stop(to);
120	mlb_evt_timer_register_count(to, event);
121	mlb_evt_timer_start(to, MLB_TIMER_ONESHOT);
122	return 0;
123}
124
125static int mlb_config_clock_source(struct timer_of *to)
126{
127	u32 val = MLB_TMR_TMCSR_CSL_DIV2;
128
129	writel_relaxed(val, timer_of_base(to) + MLB_TMR_SRC_TMCSR_OFS);
130	writel_relaxed(~0, timer_of_base(to) + MLB_TMR_SRC_TMRLR1_OFS);
131	writel_relaxed(~0, timer_of_base(to) + MLB_TMR_SRC_TMRLR2_OFS);
132	val |= MLB_TMR_TMCSR_RELD | MLB_TMR_TMCSR_CNTE | MLB_TMR_TMCSR_TRG;
133	writel_relaxed(val, timer_of_base(to) + MLB_TMR_SRC_TMCSR_OFS);
134	return 0;
135}
136
137static int mlb_config_clock_event(struct timer_of *to)
138{
139	writel_relaxed(0, timer_of_base(to) + MLB_TMR_EVT_TMCSR_OFS);
140	return 0;
141}
142
143static struct timer_of to = {
144	.flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
145
146	.clkevt = {
147		.name = "mlb-clkevt",
148		.rating = MLB_TIMER_RATING,
149		.cpumask = cpu_possible_mask,
150		.features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_ONESHOT,
151		.set_state_oneshot = mlb_set_state_oneshot,
152		.set_state_periodic = mlb_set_state_periodic,
153		.set_state_shutdown = mlb_set_state_shutdown,
154		.set_next_event = mlb_clkevt_next_event,
155	},
156
157	.of_irq = {
158		.flags = IRQF_TIMER | IRQF_IRQPOLL,
159		.handler = mlb_timer_interrupt,
160	},
161};
162
163static u64 notrace mlb_timer_sched_read(void)
164{
165	return ~readl_relaxed(timer_of_base(&to) + MLB_TMR_SRC_TMR_OFS);
166}
167
168static int __init mlb_timer_init(struct device_node *node)
169{
170	int ret;
171	unsigned long rate;
172
173	ret = timer_of_init(node, &to);
174	if (ret)
175		return ret;
176
177	rate = timer_of_rate(&to) / MLB_TMR_DIV_CNT;
178	mlb_config_clock_source(&to);
179	clocksource_mmio_init(timer_of_base(&to) + MLB_TMR_SRC_TMR_OFS,
180		node->name, rate, MLB_TIMER_RATING, 32,
181		clocksource_mmio_readl_down);
182	sched_clock_register(mlb_timer_sched_read, 32, rate);
183	mlb_config_clock_event(&to);
184	clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), 15,
185		0xffffffff);
186	return 0;
187}
188TIMER_OF_DECLARE(mlb_peritimer, "socionext,milbeaut-timer",
189		mlb_timer_init);