From mboxrd@z Thu Jan 1 00:00:00 1970 From: linus.walleij@linaro.org (Linus Walleij) Date: Thu, 30 Aug 2012 18:37:58 +0200 Subject: [PATCH] ARM: clps711x: convert to clocksource/clockevents Message-ID: <1346344678-18248-1-git-send-email-linus.walleij@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This converts the ageing clps711x timer driver to the modern clocksource/clockevent API. This was blind-coded using the datasheet, it'd be great if someone who has this machine could test it. Signed-off-by: Linus Walleij --- arch/arm/Kconfig | 3 +- arch/arm/mach-clps711x/common.c | 59 +++++++++++++++++++++++++++++--------- 2 files changed, 47 insertions(+), 15 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 181b697..8a3da9e 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -383,8 +383,9 @@ config ARCH_HIGHBANK config ARCH_CLPS711X bool "Cirrus Logic CLPS711x/EP721x/EP731x-based" select CPU_ARM720T - select ARCH_USES_GETTIMEOFFSET select NEED_MACH_MEMORY_H + select GENERIC_CLOCKEVENTS + select CLKSRC_MMIO help Support for Cirrus Logic 711x/721x/731x based boards. diff --git a/arch/arm/mach-clps711x/common.c b/arch/arm/mach-clps711x/common.c index f15293b..850697f 100644 --- a/arch/arm/mach-clps711x/common.c +++ b/arch/arm/mach-clps711x/common.c @@ -26,6 +26,8 @@ #include #include #include +#include +#include #include #include @@ -157,25 +159,42 @@ void __init clps711x_init_irq(void) clps_writel(0, KBDEOI); } -/* - * gettimeoffset() returns time since last timer tick, in usecs. - * - * 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy. - * 'tick' is usecs per jiffy. - */ -static unsigned long clps711x_gettimeoffset(void) +static void clps711x_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) { - unsigned long hwticks; - hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */ - return (hwticks * (tick_nsec / 1000)) / LATCH; + u32 syscon; + u32 period = DIV_ROUND_CLOSEST(512000, HZ); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + case CLOCK_EVT_MODE_RESUME: + /* Go into prescaler mode, program frequency */ + syscon = clps_readl(SYSCON1); + syscon |= SYSCON1_TC2M; + clps_writel(syscon, SYSCON1); + clps_writel(period, TC2D); + break; + default: + break; + } } +static struct clock_event_device clockevent_clps711x = { + .name = "clps711x_tc2d", + .rating = 300, + /* Only support periodic mode */ + .features = CLOCK_EVT_FEAT_PERIODIC, + .set_mode = clps711x_set_mode, +}; + /* * IRQ handler for the timer */ static irqreturn_t p720t_timer_interrupt(int irq, void *dev_id) { - timer_tick(); + struct clock_event_device *evt = &clockevent_clps711x; + + evt->event_handler(evt); return IRQ_HANDLED; } @@ -190,17 +209,29 @@ static void __init clps711x_timer_init(void) unsigned int syscon; syscon = clps_readl(SYSCON1); - syscon |= SYSCON1_TC2S | SYSCON1_TC2M; + /* Timer 1 in free running mode */ + syscon &= ~(SYSCON1_TC1M); + /* Timer 2 in prescale mode */ + syscon |= SYSCON1_TC2M; + /* Set both timers to 512 kHz */ + syscon |= (SYSCON1_TC1S | SYSCON1_TC2S); clps_writel(syscon, SYSCON1); - clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */ + /* Start timer 1 in free running mode */ + clps_writel(0xFFFFU, TC1D); + if (clocksource_mmio_init(CLPS711X_VIRT_BASE + TC1D, + "clps711x_tc1d", 512000, 300, 16, + clocksource_mmio_readl_down)) + pr_err("timer: failed to initialize clps711x clock source\n"); + /* Configure and register the clockevent */ + clockevents_config_and_register(&clockevent_clps711x, 512000, + 1, 0xFFFFU); setup_irq(IRQ_TC2OI, &clps711x_timer_irq); } struct sys_timer clps711x_timer = { .init = clps711x_timer_init, - .offset = clps711x_gettimeoffset, }; void clps711x_restart(char mode, const char *cmd) -- 1.7.7.6