diff options
Diffstat (limited to 'drivers/clocksource/timer-vf-pit.c')
| -rw-r--r-- | drivers/clocksource/timer-vf-pit.c | 194 |
1 files changed, 0 insertions, 194 deletions
diff --git a/drivers/clocksource/timer-vf-pit.c b/drivers/clocksource/timer-vf-pit.c deleted file mode 100644 index 911c92146eca..000000000000 --- a/drivers/clocksource/timer-vf-pit.c +++ /dev/null @@ -1,194 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright 2012-2013 Freescale Semiconductor, Inc. - */ - -#include <linux/interrupt.h> -#include <linux/clockchips.h> -#include <linux/clk.h> -#include <linux/of_address.h> -#include <linux/of_irq.h> -#include <linux/sched_clock.h> - -/* - * Each pit takes 0x10 Bytes register space - */ -#define PITMCR 0x00 -#define PIT0_OFFSET 0x100 -#define PITn_OFFSET(n) (PIT0_OFFSET + 0x10 * (n)) -#define PITLDVAL 0x00 -#define PITCVAL 0x04 -#define PITTCTRL 0x08 -#define PITTFLG 0x0c - -#define PITMCR_MDIS (0x1 << 1) - -#define PITTCTRL_TEN (0x1 << 0) -#define PITTCTRL_TIE (0x1 << 1) -#define PITCTRL_CHN (0x1 << 2) - -#define PITTFLG_TIF 0x1 - -static void __iomem *clksrc_base; -static void __iomem *clkevt_base; -static unsigned long cycle_per_jiffy; - -static inline void pit_timer_enable(void) -{ - __raw_writel(PITTCTRL_TEN | PITTCTRL_TIE, clkevt_base + PITTCTRL); -} - -static inline void pit_timer_disable(void) -{ - __raw_writel(0, clkevt_base + PITTCTRL); -} - -static inline void pit_irq_acknowledge(void) -{ - __raw_writel(PITTFLG_TIF, clkevt_base + PITTFLG); -} - -static u64 notrace pit_read_sched_clock(void) -{ - return ~__raw_readl(clksrc_base + PITCVAL); -} - -static int __init pit_clocksource_init(unsigned long rate) -{ - /* set the max load value and start the clock source counter */ - __raw_writel(0, clksrc_base + PITTCTRL); - __raw_writel(~0UL, clksrc_base + PITLDVAL); - __raw_writel(PITTCTRL_TEN, clksrc_base + PITTCTRL); - - sched_clock_register(pit_read_sched_clock, 32, rate); - return clocksource_mmio_init(clksrc_base + PITCVAL, "vf-pit", rate, - 300, 32, clocksource_mmio_readl_down); -} - -static int pit_set_next_event(unsigned long delta, - struct clock_event_device *unused) -{ - /* - * set a new value to PITLDVAL register will not restart the timer, - * to abort the current cycle and start a timer period with the new - * value, the timer must be disabled and enabled again. - * and the PITLAVAL should be set to delta minus one according to pit - * hardware requirement. - */ - pit_timer_disable(); - __raw_writel(delta - 1, clkevt_base + PITLDVAL); - pit_timer_enable(); - - return 0; -} - -static int pit_shutdown(struct clock_event_device *evt) -{ - pit_timer_disable(); - return 0; -} - -static int pit_set_periodic(struct clock_event_device *evt) -{ - pit_set_next_event(cycle_per_jiffy, evt); - return 0; -} - -static irqreturn_t pit_timer_interrupt(int irq, void *dev_id) -{ - struct clock_event_device *evt = dev_id; - - pit_irq_acknowledge(); - - /* - * pit hardware doesn't support oneshot, it will generate an interrupt - * and reload the counter value from PITLDVAL when PITCVAL reach zero, - * and start the counter again. So software need to disable the timer - * to stop the counter loop in ONESHOT mode. - */ - if (likely(clockevent_state_oneshot(evt))) - pit_timer_disable(); - - evt->event_handler(evt); - - return IRQ_HANDLED; -} - -static struct clock_event_device clockevent_pit = { - .name = "VF pit timer", - .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, - .set_state_shutdown = pit_shutdown, - .set_state_periodic = pit_set_periodic, - .set_next_event = pit_set_next_event, - .rating = 300, -}; - -static int __init pit_clockevent_init(unsigned long rate, int irq) -{ - __raw_writel(0, clkevt_base + PITTCTRL); - __raw_writel(PITTFLG_TIF, clkevt_base + PITTFLG); - - BUG_ON(request_irq(irq, pit_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL, - "VF pit timer", &clockevent_pit)); - - clockevent_pit.cpumask = cpumask_of(0); - clockevent_pit.irq = irq; - /* - * The value for the LDVAL register trigger is calculated as: - * LDVAL trigger = (period / clock period) - 1 - * The pit is a 32-bit down count timer, when the counter value - * reaches 0, it will generate an interrupt, thus the minimal - * LDVAL trigger value is 1. And then the min_delta is - * minimal LDVAL trigger value + 1, and the max_delta is full 32-bit. - */ - clockevents_config_and_register(&clockevent_pit, rate, 2, 0xffffffff); - - return 0; -} - -static int __init pit_timer_init(struct device_node *np) -{ - struct clk *pit_clk; - void __iomem *timer_base; - unsigned long clk_rate; - int irq, ret; - - timer_base = of_iomap(np, 0); - if (!timer_base) { - pr_err("Failed to iomap\n"); - return -ENXIO; - } - - /* - * PIT0 and PIT1 can be chained to build a 64-bit timer, - * so choose PIT2 as clocksource, PIT3 as clockevent device, - * and leave PIT0 and PIT1 unused for anyone else who needs them. - */ - clksrc_base = timer_base + PITn_OFFSET(2); - clkevt_base = timer_base + PITn_OFFSET(3); - - irq = irq_of_parse_and_map(np, 0); - if (irq <= 0) - return -EINVAL; - - pit_clk = of_clk_get(np, 0); - if (IS_ERR(pit_clk)) - return PTR_ERR(pit_clk); - - ret = clk_prepare_enable(pit_clk); - if (ret) - return ret; - - clk_rate = clk_get_rate(pit_clk); - cycle_per_jiffy = clk_rate / (HZ); - - /* enable the pit module */ - __raw_writel(~PITMCR_MDIS, timer_base + PITMCR); - - ret = pit_clocksource_init(clk_rate); - if (ret) - return ret; - - return pit_clockevent_init(clk_rate, irq); -} -TIMER_OF_DECLARE(vf610, "fsl,vf610-pit", pit_timer_init); |