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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(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 | + |
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