diff options
Diffstat (limited to 'drivers/clocksource/timer-npcm7xx.c')
| -rw-r--r-- | drivers/clocksource/timer-npcm7xx.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-npcm7xx.c b/drivers/clocksource/timer-npcm7xx.c new file mode 100644 index 000000000..9780ffd80 --- /dev/null +++ b/drivers/clocksource/timer-npcm7xx.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2014-2018 Nuvoton Technologies tomer.maimon@nuvoton.com + * All rights reserved. + * + * Copyright 2017 Google, Inc. + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/clockchips.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> +#include "timer-of.h" + +/* Timers registers */ +#define NPCM7XX_REG_TCSR0 0x0 /* Timer 0 Control and Status Register */ +#define NPCM7XX_REG_TICR0 0x8 /* Timer 0 Initial Count Register */ +#define NPCM7XX_REG_TCSR1 0x4 /* Timer 1 Control and Status Register */ +#define NPCM7XX_REG_TICR1 0xc /* Timer 1 Initial Count Register */ +#define NPCM7XX_REG_TDR1 0x14 /* Timer 1 Data Register */ +#define NPCM7XX_REG_TISR 0x18 /* Timer Interrupt Status Register */ + +/* Timers control */ +#define NPCM7XX_Tx_RESETINT 0x1f +#define NPCM7XX_Tx_PERIOD BIT(27) +#define NPCM7XX_Tx_INTEN BIT(29) +#define NPCM7XX_Tx_COUNTEN BIT(30) +#define NPCM7XX_Tx_ONESHOT 0x0 +#define NPCM7XX_Tx_OPER GENMASK(28, 27) +#define NPCM7XX_Tx_MIN_PRESCALE 0x1 +#define NPCM7XX_Tx_TDR_MASK_BITS 24 +#define NPCM7XX_Tx_MAX_CNT 0xFFFFFF +#define NPCM7XX_T0_CLR_INT 0x1 +#define NPCM7XX_Tx_CLR_CSR 0x0 + +/* Timers operating mode */ +#define NPCM7XX_START_PERIODIC_Tx (NPCM7XX_Tx_PERIOD | NPCM7XX_Tx_COUNTEN | \ + NPCM7XX_Tx_INTEN | \ + NPCM7XX_Tx_MIN_PRESCALE) + +#define NPCM7XX_START_ONESHOT_Tx (NPCM7XX_Tx_ONESHOT | NPCM7XX_Tx_COUNTEN | \ + NPCM7XX_Tx_INTEN | \ + NPCM7XX_Tx_MIN_PRESCALE) + +#define NPCM7XX_START_Tx (NPCM7XX_Tx_COUNTEN | NPCM7XX_Tx_PERIOD | \ + NPCM7XX_Tx_MIN_PRESCALE) + +#define NPCM7XX_DEFAULT_CSR (NPCM7XX_Tx_CLR_CSR | NPCM7XX_Tx_MIN_PRESCALE) + +static int npcm7xx_timer_resume(struct clock_event_device *evt) +{ + struct timer_of *to = to_timer_of(evt); + u32 val; + + val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); + val |= NPCM7XX_Tx_COUNTEN; + writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); + + return 0; +} + +static int npcm7xx_timer_shutdown(struct clock_event_device *evt) +{ + struct timer_of *to = to_timer_of(evt); + u32 val; + + val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); + val &= ~NPCM7XX_Tx_COUNTEN; + writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); + + return 0; +} + +static int npcm7xx_timer_oneshot(struct clock_event_device *evt) +{ + struct timer_of *to = to_timer_of(evt); + u32 val; + + val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); + val &= ~NPCM7XX_Tx_OPER; + val |= NPCM7XX_START_ONESHOT_Tx; + writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); + + return 0; +} + +static int npcm7xx_timer_periodic(struct clock_event_device *evt) +{ + struct timer_of *to = to_timer_of(evt); + u32 val; + + writel(timer_of_period(to), timer_of_base(to) + NPCM7XX_REG_TICR0); + + val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); + val &= ~NPCM7XX_Tx_OPER; + val |= NPCM7XX_START_PERIODIC_Tx; + writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); + + return 0; +} + +static int npcm7xx_clockevent_set_next_event(unsigned long evt, + struct clock_event_device *clk) +{ + struct timer_of *to = to_timer_of(clk); + u32 val; + + writel(evt, timer_of_base(to) + NPCM7XX_REG_TICR0); + val = readl(timer_of_base(to) + NPCM7XX_REG_TCSR0); + val |= NPCM7XX_START_Tx; + writel(val, timer_of_base(to) + NPCM7XX_REG_TCSR0); + + return 0; +} + +static irqreturn_t npcm7xx_timer0_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = (struct clock_event_device *)dev_id; + struct timer_of *to = to_timer_of(evt); + + writel(NPCM7XX_T0_CLR_INT, timer_of_base(to) + NPCM7XX_REG_TISR); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct timer_of npcm7xx_to = { + .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK, + + .clkevt = { + .name = "npcm7xx-timer0", + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = npcm7xx_clockevent_set_next_event, + .set_state_shutdown = npcm7xx_timer_shutdown, + .set_state_periodic = npcm7xx_timer_periodic, + .set_state_oneshot = npcm7xx_timer_oneshot, + .tick_resume = npcm7xx_timer_resume, + .rating = 300, + }, + + .of_irq = { + .handler = npcm7xx_timer0_interrupt, + .flags = IRQF_TIMER | IRQF_IRQPOLL, + }, +}; + +static void __init npcm7xx_clockevents_init(void) +{ + writel(NPCM7XX_DEFAULT_CSR, + timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR0); + + writel(NPCM7XX_Tx_RESETINT, + timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TISR); + + npcm7xx_to.clkevt.cpumask = cpumask_of(0); + clockevents_config_and_register(&npcm7xx_to.clkevt, + timer_of_rate(&npcm7xx_to), + 0x1, NPCM7XX_Tx_MAX_CNT); +} + +static void __init npcm7xx_clocksource_init(void) +{ + u32 val; + + writel(NPCM7XX_DEFAULT_CSR, + timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1); + writel(NPCM7XX_Tx_MAX_CNT, + timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TICR1); + + val = readl(timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1); + val |= NPCM7XX_START_Tx; + writel(val, timer_of_base(&npcm7xx_to) + NPCM7XX_REG_TCSR1); + + clocksource_mmio_init(timer_of_base(&npcm7xx_to) + + NPCM7XX_REG_TDR1, + "npcm7xx-timer1", timer_of_rate(&npcm7xx_to), + 200, (unsigned int)NPCM7XX_Tx_TDR_MASK_BITS, + clocksource_mmio_readl_down); +} + +static int __init npcm7xx_timer_init(struct device_node *np) +{ + int ret; + + ret = timer_of_init(np, &npcm7xx_to); + if (ret) + return ret; + + /* Clock input is divided by PRESCALE + 1 before it is fed */ + /* to the counter */ + npcm7xx_to.of_clk.rate = npcm7xx_to.of_clk.rate / + (NPCM7XX_Tx_MIN_PRESCALE + 1); + + npcm7xx_clocksource_init(); + npcm7xx_clockevents_init(); + + pr_info("Enabling NPCM7xx clocksource timer base: %px, IRQ: %d ", + timer_of_base(&npcm7xx_to), timer_of_irq(&npcm7xx_to)); + + return 0; +} + +TIMER_OF_DECLARE(npcm7xx, "nuvoton,npcm750-timer", npcm7xx_timer_init); + |