--- /dev/null
+/*
+ * arch/arm/mach-lpc32xx/timer.c
+ *
+ * Author: Kevin Wells <kevin.wells@nxp.com>
+ *
+ * Copyright (C) 2009 - 2010 NXP Semiconductors
+ * Copyright (C) 2009 Fontys University of Applied Sciences, Eindhoven
+ * Ed Schouten <e.schouten@fontys.nl>
+ * Laurens Timmermans <l.timmermans@fontys.nl>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/time.h>
+#include <linux/err.h>
+#include <linux/clockchips.h>
+
+#include <asm/mach/time.h>
+
+#include <mach/hardware.h>
+#include <mach/platform.h>
+#include "common.h"
+
+static int lpc32xx_clkevt_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ __raw_writel(LPC32XX_TIMER_CNTR_TCR_RESET,
+ LPC32XX_TIMER_TCR(LPC32XX_TIMER0_BASE));
+ __raw_writel(delta, LPC32XX_TIMER_PR(LPC32XX_TIMER0_BASE));
+ __raw_writel(LPC32XX_TIMER_CNTR_TCR_EN,
+ LPC32XX_TIMER_TCR(LPC32XX_TIMER0_BASE));
+
+ return 0;
+}
+
+static void lpc32xx_clkevt_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ WARN_ON(1);
+ break;
+
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ /*
+ * Disable the timer. When using oneshot, we must also
+ * disable the timer to wait for the first call to
+ * set_next_event().
+ */
+ __raw_writel(0, LPC32XX_TIMER_TCR(LPC32XX_TIMER0_BASE));
+ break;
+
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+}
+
+static struct clock_event_device lpc32xx_clkevt = {
+ .name = "lpc32xx_clkevt",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 300,
+ .set_next_event = lpc32xx_clkevt_next_event,
+ .set_mode = lpc32xx_clkevt_mode,
+};
+
+static irqreturn_t lpc32xx_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &lpc32xx_clkevt;
+
+ /* Clear match */
+ __raw_writel(LPC32XX_TIMER_CNTR_MTCH_BIT(0),
+ LPC32XX_TIMER_IR(LPC32XX_TIMER0_BASE));
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction lpc32xx_timer_irq = {
+ .name = "LPC32XX Timer Tick",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = lpc32xx_timer_interrupt,
+};
+
+/*
+ * The clock management driver isn't initialized at this point, so the
+ * clocks need to be enabled here manually and then tagged as used in
+ * the clock driver initialization
+ */
+void __init lpc32xx_timer_init(void)
+{
+ u32 clkrate, pllreg;
+
+ /* Enable timer clock */
+ __raw_writel(LPC32XX_CLKPWR_TMRPWMCLK_TIMER0_EN |
+ LPC32XX_CLKPWR_TMRPWMCLK_TIMER1_EN,
+ LPC32XX_CLKPWR_TIMERS_PWMS_CLK_CTRL_1);
+
+ /*
+ * The clock driver isn't initialized at this point. So determine if
+ * the SYSCLK is driven from the PLL397 or main oscillator and then use
+ * it to compute the PLL frequency and the PCLK divider to get the base
+ * timer rates. This rate is needed to compute the tick rate.
+ */
+ if (clk_is_sysclk_mainosc() != 0)
+ clkrate = LPC32XX_MAIN_OSC_FREQ;
+ else
+ clkrate = 397 * LPC32XX_CLOCK_OSC_FREQ;
+
+ /* Get ARM HCLKPLL register and convert it into a frequency */
+ pllreg = __raw_readl(LPC32XX_CLKPWR_HCLKPLL_CTRL) & 0x1FFFF;
+ clkrate = clk_get_pllrate_from_reg(clkrate, pllreg);
+
+ /* Get PCLK divider and divide ARM PLL clock by it to get timer rate */
+ clkrate = clkrate / clk_get_pclk_div();
+
+ /* Initial timer setup */
+ __raw_writel(0, LPC32XX_TIMER_TCR(LPC32XX_TIMER0_BASE));
+ __raw_writel(LPC32XX_TIMER_CNTR_MTCH_BIT(0),
+ LPC32XX_TIMER_IR(LPC32XX_TIMER0_BASE));
+ __raw_writel(1, LPC32XX_TIMER_MR0(LPC32XX_TIMER0_BASE));
+ __raw_writel(LPC32XX_TIMER_CNTR_MCR_MTCH(0) |
+ LPC32XX_TIMER_CNTR_MCR_STOP(0) |
+ LPC32XX_TIMER_CNTR_MCR_RESET(0),
+ LPC32XX_TIMER_MCR(LPC32XX_TIMER0_BASE));
+
+ /* Setup tick interrupt */
+ setup_irq(IRQ_LPC32XX_TIMER0, &lpc32xx_timer_irq);
+
+ /* Setup the clockevent structure. */
+ lpc32xx_clkevt.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&lpc32xx_clkevt, clkrate, 1, -1);
+
+ /* Use timer1 as clock source. */
+ __raw_writel(LPC32XX_TIMER_CNTR_TCR_RESET,
+ LPC32XX_TIMER_TCR(LPC32XX_TIMER1_BASE));
+ __raw_writel(0, LPC32XX_TIMER_PR(LPC32XX_TIMER1_BASE));
+ __raw_writel(0, LPC32XX_TIMER_MCR(LPC32XX_TIMER1_BASE));
+ __raw_writel(LPC32XX_TIMER_CNTR_TCR_EN,
+ LPC32XX_TIMER_TCR(LPC32XX_TIMER1_BASE));
+
+ clocksource_mmio_init(LPC32XX_TIMER_TC(LPC32XX_TIMER1_BASE),
+ "lpc32xx_clksrc", clkrate, 300, 32, clocksource_mmio_readl_up);
+}
Code Review / kvmfornfv.git / blobdiff