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1c00289e TM |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Copyright (C) 2014-2018 Nuvoton Technologies tomer.maimon@nuvoton.com | |
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(3, 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 | ||
56 | static 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 | ||
68 | static 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 | ||
80 | static 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 | ||
88 | val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); | |
89 | val |= NPCM7XX_START_ONESHOT_Tx; | |
90 | writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); | |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
95 | static int npcm7xx_timer_periodic(struct clock_event_device *evt) | |
96 | { | |
97 | struct timer_of *to = to_timer_of(evt); | |
98 | u32 val; | |
99 | ||
100 | val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); | |
101 | val &= ~NPCM7XX_Tx_OPER; | |
102 | ||
103 | writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0); | |
104 | val |= NPCM7XX_START_PERIODIC_Tx; | |
105 | ||
106 | writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static int npcm7xx_clockevent_set_next_event(unsigned long evt, | |
112 | struct clock_event_device *clk) | |
113 | { | |
114 | struct timer_of *to = to_timer_of(clk); | |
115 | u32 val; | |
116 | ||
117 | writel(evt, timer_of_base(to) + NPCM7XX_REG_TICR0); | |
118 | val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); | |
119 | val |= NPCM7XX_START_Tx; | |
120 | writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); | |
121 | ||
122 | return 0; | |
123 | } | |
124 | ||
125 | static irqreturn_t npcm7xx_timer0_interrupt(int irq, void *dev_id) | |
126 | { | |
127 | struct clock_event_device *evt = (struct clock_event_device *)dev_id; | |
128 | struct timer_of *to = to_timer_of(evt); | |
129 | ||
130 | writel(NPCM7XX_T0_CLR_INT, timer_of_base(to) + NPCM7XX_REG_TISR); | |
131 | ||
132 | evt->event_handler(evt); | |
133 | ||
134 | return IRQ_HANDLED; | |
135 | } | |
136 | ||
137 | static struct timer_of npcm7xx_to = { | |
138 | .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK, | |
139 | ||
140 | .clkevt = { | |
141 | .name = "npcm7xx-timer0", | |
142 | .features = CLOCK_EVT_FEAT_PERIODIC | | |
143 | CLOCK_EVT_FEAT_ONESHOT, | |
144 | .set_next_event = npcm7xx_clockevent_set_next_event, | |
145 | .set_state_shutdown = npcm7xx_timer_shutdown, | |
146 | .set_state_periodic = npcm7xx_timer_periodic, | |
147 | .set_state_oneshot = npcm7xx_timer_oneshot, | |
148 | .tick_resume = npcm7xx_timer_resume, | |
149 | .rating = 300, | |
150 | }, | |
151 | ||
152 | .of_irq = { | |
153 | .handler = npcm7xx_timer0_interrupt, | |
154 | .flags = IRQF_TIMER | IRQF_IRQPOLL, | |
155 | }, | |
156 | }; | |
157 | ||
158 | static void __init npcm7xx_clockevents_init(void) | |
159 | { | |
160 | writel(NPCM7XX_DEFAULT_CSR, | |
161 | timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR0); | |
162 | ||
163 | writel(NPCM7XX_Tx_RESETINT, | |
164 | timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TISR); | |
165 | ||
166 | npcm7xx_to.clkevt.cpumask = cpumask_of(0); | |
167 | clockevents_config_and_register(&npcm7xx_to.clkevt, | |
168 | timer_of_rate(&npcm7xx_to), | |
169 | 0x1, NPCM7XX_Tx_MAX_CNT); | |
170 | } | |
171 | ||
172 | static void __init npcm7xx_clocksource_init(void) | |
173 | { | |
174 | u32 val; | |
175 | ||
176 | writel(NPCM7XX_DEFAULT_CSR, | |
177 | timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1); | |
178 | writel(NPCM7XX_Tx_MAX_CNT, | |
179 | timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TICR1); | |
180 | ||
181 | val = readl(timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1); | |
182 | val |= NPCM7XX_START_Tx; | |
183 | writel(val, timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1); | |
184 | ||
185 | clocksource_mmio_init(timer_of_base(&npcm7xx_to) + | |
186 | NPCM7XX_REG_TDR1, | |
187 | "npcm7xx-timer1", timer_of_rate(&npcm7xx_to), | |
188 | 200, (unsigned int)NPCM7XX_Tx_TDR_MASK_BITS, | |
189 | clocksource_mmio_readl_down); | |
190 | } | |
191 | ||
192 | static int __init npcm7xx_timer_init(struct device_node *np) | |
193 | { | |
194 | int ret; | |
195 | ||
196 | ret = timer_of_init(np, &npcm7xx_to); | |
197 | if (ret) | |
198 | return ret; | |
199 | ||
200 | /* Clock input is divided by PRESCALE + 1 before it is fed */ | |
201 | /* to the counter */ | |
202 | npcm7xx_to.of_clk.rate = npcm7xx_to.of_clk.rate / | |
203 | (NPCM7XX_Tx_MIN_PRESCALE + 1); | |
204 | ||
205 | npcm7xx_clocksource_init(); | |
206 | npcm7xx_clockevents_init(); | |
207 | ||
208 | pr_info("Enabling NPCM7xx clocksource timer base: %px, IRQ: %d ", | |
209 | timer_of_base(&npcm7xx_to), timer_of_irq(&npcm7xx_to)); | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | TIMER_OF_DECLARE(npcm7xx, "nuvoton,npcm750-timer", npcm7xx_timer_init); | |
215 |