diff options
Diffstat (limited to 'drivers/clocksource/timer-nps.c')
| -rw-r--r-- | drivers/clocksource/timer-nps.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-nps.c b/drivers/clocksource/timer-nps.c index 0c8e21f905d7..b4c8a023a2d4 100644 --- a/drivers/clocksource/timer-nps.c +++ b/drivers/clocksource/timer-nps.c @@ -111,3 +111,173 @@ static int __init nps_setup_clocksource(struct device_node *node) CLOCKSOURCE_OF_DECLARE(ezchip_nps400_clksrc, "ezchip,nps400-timer", nps_setup_clocksource); +CLOCKSOURCE_OF_DECLARE(ezchip_nps400_clk_src, "ezchip,nps400-timer1", + nps_setup_clocksource); + +#ifdef CONFIG_EZNPS_MTM_EXT +#include <soc/nps/mtm.h> + +/* Timer related Aux registers */ +#define NPS_REG_TIMER0_TSI 0xFFFFF850 +#define NPS_REG_TIMER0_LIMIT 0x23 +#define NPS_REG_TIMER0_CTRL 0x22 +#define NPS_REG_TIMER0_CNT 0x21 + +/* + * Interrupt Enabled (IE) - re-arm the timer + * Not Halted (NH) - is cleared when working with JTAG (for debug) + */ +#define TIMER0_CTRL_IE BIT(0) +#define TIMER0_CTRL_NH BIT(1) + +static unsigned long nps_timer0_freq; +static unsigned long nps_timer0_irq; + +static void nps_clkevent_rm_thread(void) +{ + int thread; + unsigned int cflags, enabled_threads; + + hw_schd_save(&cflags); + + enabled_threads = read_aux_reg(NPS_REG_TIMER0_TSI); + + /* remove thread from TSI1 */ + thread = read_aux_reg(CTOP_AUX_THREAD_ID); + enabled_threads &= ~(1 << thread); + write_aux_reg(NPS_REG_TIMER0_TSI, enabled_threads); + + /* Acknowledge and if needed re-arm the timer */ + if (!enabled_threads) + write_aux_reg(NPS_REG_TIMER0_CTRL, TIMER0_CTRL_NH); + else + write_aux_reg(NPS_REG_TIMER0_CTRL, + TIMER0_CTRL_IE | TIMER0_CTRL_NH); + + hw_schd_restore(cflags); +} + +static void nps_clkevent_add_thread(unsigned long delta) +{ + int thread; + unsigned int cflags, enabled_threads; + + hw_schd_save(&cflags); + + /* add thread to TSI1 */ + thread = read_aux_reg(CTOP_AUX_THREAD_ID); + enabled_threads = read_aux_reg(NPS_REG_TIMER0_TSI); + enabled_threads |= (1 << thread); + write_aux_reg(NPS_REG_TIMER0_TSI, enabled_threads); + + /* set next timer event */ + write_aux_reg(NPS_REG_TIMER0_LIMIT, delta); + write_aux_reg(NPS_REG_TIMER0_CNT, 0); + write_aux_reg(NPS_REG_TIMER0_CTRL, + TIMER0_CTRL_IE | TIMER0_CTRL_NH); + + hw_schd_restore(cflags); +} + +/* + * Whenever anyone tries to change modes, we just mask interrupts + * and wait for the next event to get set. + */ +static int nps_clkevent_set_state(struct clock_event_device *dev) +{ + nps_clkevent_rm_thread(); + disable_percpu_irq(nps_timer0_irq); + + return 0; +} + +static int nps_clkevent_set_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + nps_clkevent_add_thread(delta); + enable_percpu_irq(nps_timer0_irq, IRQ_TYPE_NONE); + + return 0; +} + +static DEFINE_PER_CPU(struct clock_event_device, nps_clockevent_device) = { + .name = "NPS Timer0", + .features = CLOCK_EVT_FEAT_ONESHOT, + .rating = 300, + .set_next_event = nps_clkevent_set_next_event, + .set_state_oneshot = nps_clkevent_set_state, + .set_state_oneshot_stopped = nps_clkevent_set_state, + .set_state_shutdown = nps_clkevent_set_state, + .tick_resume = nps_clkevent_set_state, +}; + +static irqreturn_t timer_irq_handler(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + nps_clkevent_rm_thread(); + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static int nps_timer_starting_cpu(unsigned int cpu) +{ + struct clock_event_device *evt = this_cpu_ptr(&nps_clockevent_device); + + evt->cpumask = cpumask_of(smp_processor_id()); + + clockevents_config_and_register(evt, nps_timer0_freq, 0, ULONG_MAX); + enable_percpu_irq(nps_timer0_irq, IRQ_TYPE_NONE); + + return 0; +} + +static int nps_timer_dying_cpu(unsigned int cpu) +{ + disable_percpu_irq(nps_timer0_irq); + return 0; +} + +static int __init nps_setup_clockevent(struct device_node *node) +{ + struct clk *clk; + int ret; + + nps_timer0_irq = irq_of_parse_and_map(node, 0); + if (nps_timer0_irq <= 0) { + pr_err("clockevent: missing irq"); + return -EINVAL; + } + + ret = nps_get_timer_clk(node, &nps_timer0_freq, &clk); + if (ret) + return ret; + + /* Needs apriori irq_set_percpu_devid() done in intc map function */ + ret = request_percpu_irq(nps_timer0_irq, timer_irq_handler, + "Timer0 (per-cpu-tick)", + &nps_clockevent_device); + if (ret) { + pr_err("Couldn't request irq\n"); + clk_disable_unprepare(clk); + return ret; + } + + ret = cpuhp_setup_state(CPUHP_AP_ARC_TIMER_STARTING, + "clockevents/nps:starting", + nps_timer_starting_cpu, + nps_timer_dying_cpu); + if (ret) { + pr_err("Failed to setup hotplug state"); + clk_disable_unprepare(clk); + free_percpu_irq(nps_timer0_irq, &nps_clockevent_device); + return ret; + } + + return 0; +} + +CLOCKSOURCE_OF_DECLARE(ezchip_nps400_clk_evt, "ezchip,nps400-timer0", + nps_setup_clockevent); +#endif /* CONFIG_EZNPS_MTM_EXT */ |