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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2014-2018 Nuvoton Technologies [email protected]
4 * All rights reserved.
5 *
6 * Copyright 2017 Google, Inc.
7 */
8
9#include <linux/kernel.h>
10#include <linux/sched.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/err.h>
14#include <linux/clk.h>
15#include <linux/io.h>
16#include <linux/clockchips.h>
17#include <linux/of_irq.h>
18#include <linux/of_address.h>
19#include "timer-of.h"
20
21/* Timers registers */
22#define NPCM7XX_REG_TCSR0 0x0 /* Timer 0 Control and Status Register */
23#define NPCM7XX_REG_TICR0 0x8 /* Timer 0 Initial Count Register */
24#define NPCM7XX_REG_TCSR1 0x4 /* Timer 1 Control and Status Register */
25#define NPCM7XX_REG_TICR1 0xc /* Timer 1 Initial Count Register */
26#define NPCM7XX_REG_TDR1 0x14 /* Timer 1 Data Register */
27#define NPCM7XX_REG_TISR 0x18 /* Timer Interrupt Status Register */
28
29/* Timers control */
30#define NPCM7XX_Tx_RESETINT 0x1f
31#define NPCM7XX_Tx_PERIOD BIT(27)
32#define NPCM7XX_Tx_INTEN BIT(29)
33#define NPCM7XX_Tx_COUNTEN BIT(30)
34#define NPCM7XX_Tx_ONESHOT 0x0
35#define NPCM7XX_Tx_OPER GENMASK(28, 27)
36#define NPCM7XX_Tx_MIN_PRESCALE 0x1
37#define NPCM7XX_Tx_TDR_MASK_BITS 24
38#define NPCM7XX_Tx_MAX_CNT 0xFFFFFF
39#define NPCM7XX_T0_CLR_INT 0x1
40#define NPCM7XX_Tx_CLR_CSR 0x0
41
42/* Timers operating mode */
43#define NPCM7XX_START_PERIODIC_Tx (NPCM7XX_Tx_PERIOD | NPCM7XX_Tx_COUNTEN | \
44 NPCM7XX_Tx_INTEN | \
45 NPCM7XX_Tx_MIN_PRESCALE)
46
47#define NPCM7XX_START_ONESHOT_Tx (NPCM7XX_Tx_ONESHOT | NPCM7XX_Tx_COUNTEN | \
48 NPCM7XX_Tx_INTEN | \
49 NPCM7XX_Tx_MIN_PRESCALE)
50
51#define NPCM7XX_START_Tx (NPCM7XX_Tx_COUNTEN | NPCM7XX_Tx_PERIOD | \
52 NPCM7XX_Tx_MIN_PRESCALE)
53
54#define NPCM7XX_DEFAULT_CSR (NPCM7XX_Tx_CLR_CSR | NPCM7XX_Tx_MIN_PRESCALE)
55
56static int npcm7xx_timer_resume(struct clock_event_device *evt)
57{
58 struct timer_of *to = to_timer_of(evt);
59 u32 val;
60
61 val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
62 val |= NPCM7XX_Tx_COUNTEN;
63 writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
64
65 return 0;
66}
67
68static int npcm7xx_timer_shutdown(struct clock_event_device *evt)
69{
70 struct timer_of *to = to_timer_of(evt);
71 u32 val;
72
73 val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
74 val &= ~NPCM7XX_Tx_COUNTEN;
75 writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
76
77 return 0;
78}
79
80static int npcm7xx_timer_oneshot(struct clock_event_device *evt)
81{
82 struct timer_of *to = to_timer_of(evt);
83 u32 val;
84
85 val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
86 val &= ~NPCM7XX_Tx_OPER;
87 val |= NPCM7XX_START_ONESHOT_Tx;
88 writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
89
90 return 0;
91}
92
93static int npcm7xx_timer_periodic(struct clock_event_device *evt)
94{
95 struct timer_of *to = to_timer_of(evt);
96 u32 val;
97
98 writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0);
99
100 val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
101 val &= ~NPCM7XX_Tx_OPER;
102 val |= NPCM7XX_START_PERIODIC_Tx;
103 writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
104
105 return 0;
106}
107
108static int npcm7xx_clockevent_set_next_event(unsigned long evt,
109 struct clock_event_device *clk)
110{
111 struct timer_of *to = to_timer_of(clk);
112 u32 val;
113
114 writel(evt, timer_of_base(to) + NPCM7XX_REG_TICR0);
115 val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0);
116 val |= NPCM7XX_START_Tx;
117 writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0);
118
119 return 0;
120}
121
122static irqreturn_t npcm7xx_timer0_interrupt(int irq, void *dev_id)
123{
124 struct clock_event_device *evt = (struct clock_event_device *)dev_id;
125 struct timer_of *to = to_timer_of(evt);
126
127 writel(NPCM7XX_T0_CLR_INT, timer_of_base(to) + NPCM7XX_REG_TISR);
128
129 evt->event_handler(evt);
130
131 return IRQ_HANDLED;
132}
133
134static struct timer_of npcm7xx_to = {
135 .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
136
137 .clkevt = {
138 .name = "npcm7xx-timer0",
139 .features = CLOCK_EVT_FEAT_PERIODIC |
140 CLOCK_EVT_FEAT_ONESHOT,
141 .set_next_event = npcm7xx_clockevent_set_next_event,
142 .set_state_shutdown = npcm7xx_timer_shutdown,
143 .set_state_periodic = npcm7xx_timer_periodic,
144 .set_state_oneshot = npcm7xx_timer_oneshot,
145 .tick_resume = npcm7xx_timer_resume,
146 .rating = 300,
147 },
148
149 .of_irq = {
150 .handler = npcm7xx_timer0_interrupt,
151 .flags = IRQF_TIMER | IRQF_IRQPOLL,
152 },
153};
154
155static void __init npcm7xx_clockevents_init(void)
156{
157 writel(NPCM7XX_DEFAULT_CSR,
158 timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR0);
159
160 writel(NPCM7XX_Tx_RESETINT,
161 timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TISR);
162
163 npcm7xx_to.clkevt.cpumask = cpumask_of(0);
164 clockevents_config_and_register(&npcm7xx_to.clkevt,
165 timer_of_rate(&npcm7xx_to),
166 0x1, NPCM7XX_Tx_MAX_CNT);
167}
168
169static void __init npcm7xx_clocksource_init(void)
170{
171 u32 val;
172
173 writel(NPCM7XX_DEFAULT_CSR,
174 timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1);
175 writel(NPCM7XX_Tx_MAX_CNT,
176 timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TICR1);
177
178 val = readl(timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1);
179 val |= NPCM7XX_START_Tx;
180 writel(val, timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1);
181
182 clocksource_mmio_init(timer_of_base(&npcm7xx_to) +
183 NPCM7XX_REG_TDR1,
184 "npcm7xx-timer1", timer_of_rate(&npcm7xx_to),
185 200, (unsigned int)NPCM7XX_Tx_TDR_MASK_BITS,
186 clocksource_mmio_readl_down);
187}
188
189static int __init npcm7xx_timer_init(struct device_node *np)
190{
191 struct clk *clk;
192 int ret;
193
194 ret = timer_of_init(np, &npcm7xx_to);
195 if (ret)
196 return ret;
197
198 /* Clock input is divided by PRESCALE + 1 before it is fed */
199 /* to the counter */
200 npcm7xx_to.of_clk.rate = npcm7xx_to.of_clk.rate /
201 (NPCM7XX_Tx_MIN_PRESCALE + 1);
202
203 /* Enable the clock for timer1, if it exists */
204 clk = of_clk_get(np, 1);
205 if (clk) {
206 if (!IS_ERR(clk))
207 clk_prepare_enable(clk);
208 else
209 pr_warn("%pOF: Failed to get clock for timer1: %pe", np, clk);
210 }
211
212 npcm7xx_clocksource_init();
213 npcm7xx_clockevents_init();
214
215 pr_info("Enabling NPCM7xx clocksource timer base: %px, IRQ: %d ",
216 timer_of_base(&npcm7xx_to), timer_of_irq(&npcm7xx_to));
217
218 return 0;
219}
220
221TIMER_OF_DECLARE(wpcm450, "nuvoton,wpcm450-timer", npcm7xx_timer_init);
222TIMER_OF_DECLARE(npcm7xx, "nuvoton,npcm750-timer", npcm7xx_timer_init);
223