ARM: LPC32XX: GPIO, timer, and IRQ drivers

Common drivers for the LPC32XX used on all platforms
Signed-off-by: Kevin Wells <wellsk40@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

arch/arm/mach-lpc32xx/timer.c

+/*
+ * 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 cycle_t lpc32xx_clksrc_read(struct clocksource *cs)
+{
+	return (cycle_t)__raw_readl(LCP32XX_TIMER_TC(LPC32XX_TIMER1_BASE));
+}
+
+static struct clocksource lpc32xx_clksrc = {
+	.name	= "lpc32xx_clksrc",
+	.shift	= 24,
+	.rating	= 300,
+	.read	= lpc32xx_clksrc_read,
+	.mask	= CLOCKSOURCE_MASK(32),
+	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int lpc32xx_clkevt_next_event(unsigned long delta,
+    struct clock_event_device *dev)
+{
+	__raw_writel(LCP32XX_TIMER_CNTR_TCR_RESET,
+		LCP32XX_TIMER_TCR(LPC32XX_TIMER0_BASE));
+	__raw_writel(delta, LCP32XX_TIMER_PR(LPC32XX_TIMER0_BASE));
+	__raw_writel(LCP32XX_TIMER_CNTR_TCR_EN,
+		LCP32XX_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, LCP32XX_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,
+	.shift		= 32,
+	.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(LCP32XX_TIMER_CNTR_MTCH_BIT(0),
+		LCP32XX_TIMER_IR(LPC32XX_TIMER0_BASE));
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction lpc32xx_timer_irq = {
+	.name		= "LPC32XX Timer Tick",
+	.flags		= IRQF_DISABLED | 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
+ */
+static 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, LCP32XX_TIMER_TCR(LPC32XX_TIMER0_BASE));
+	__raw_writel(LCP32XX_TIMER_CNTR_MTCH_BIT(0),
+		LCP32XX_TIMER_IR(LPC32XX_TIMER0_BASE));
+	__raw_writel(1, LCP32XX_TIMER_MR0(LPC32XX_TIMER0_BASE));
+	__raw_writel(LCP32XX_TIMER_CNTR_MCR_MTCH(0) |
+		LCP32XX_TIMER_CNTR_MCR_STOP(0) |
+		LCP32XX_TIMER_CNTR_MCR_RESET(0),
+		LCP32XX_TIMER_MCR(LPC32XX_TIMER0_BASE));
+
+	/* Setup tick interrupt */
+	setup_irq(IRQ_LPC32XX_TIMER0, &lpc32xx_timer_irq);
+
+	/* Setup the clockevent structure. */
+	lpc32xx_clkevt.mult = div_sc(clkrate, NSEC_PER_SEC,
+		lpc32xx_clkevt.shift);
+	lpc32xx_clkevt.max_delta_ns = clockevent_delta2ns(-1,
+		&lpc32xx_clkevt);
+	lpc32xx_clkevt.min_delta_ns = clockevent_delta2ns(1,
+		&lpc32xx_clkevt) + 1;
+	lpc32xx_clkevt.cpumask = cpumask_of(0);
+	clockevents_register_device(&lpc32xx_clkevt);
+
+	/* Use timer1 as clock source. */
+	__raw_writel(LCP32XX_TIMER_CNTR_TCR_RESET,
+		LCP32XX_TIMER_TCR(LPC32XX_TIMER1_BASE));
+	__raw_writel(0, LCP32XX_TIMER_PR(LPC32XX_TIMER1_BASE));
+	__raw_writel(0, LCP32XX_TIMER_MCR(LPC32XX_TIMER1_BASE));
+	__raw_writel(LCP32XX_TIMER_CNTR_TCR_EN,
+		LCP32XX_TIMER_TCR(LPC32XX_TIMER1_BASE));
+	lpc32xx_clksrc.mult = clocksource_hz2mult(clkrate,
+		lpc32xx_clksrc.shift);
+	clocksource_register(&lpc32xx_clksrc);
+}
+
+struct sys_timer lpc32xx_timer = {
+	.init		= &lpc32xx_timer_init,
+};
+