ARM: Xilinx: Adding Xilinx board support
The 1st board support is minimal to get a system up and running
on the Xilinx platform.
This platform reuses the clock implementation from plat-versatile, and
it depends entirely on CONFIG_OF support. There is only one board
support file which obtains all device information from a device tree
dtb file which is passed to the kernel at boot time.
Signed-off-by: John Linn <john.linn@xilinx.com>
diff --git a/arch/arm/mach-zynq/timer.c b/arch/arm/mach-zynq/timer.c
new file mode 100644
index 0000000..c2c96cc
--- /dev/null
+++ b/arch/arm/mach-zynq/timer.c
@@ -0,0 +1,298 @@
+/*
+ * This file contains driver for the Xilinx PS Timer Counter IP.
+ *
+ * Copyright (C) 2011 Xilinx
+ *
+ * based on arch/mips/kernel/time.c timer driver
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/types.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/io.h>
+
+#include <asm/mach/time.h>
+#include <mach/zynq_soc.h>
+#include "common.h"
+
+#define IRQ_TIMERCOUNTER0 42
+
+/*
+ * This driver configures the 2 16-bit count-up timers as follows:
+ *
+ * T1: Timer 1, clocksource for generic timekeeping
+ * T2: Timer 2, clockevent source for hrtimers
+ * T3: Timer 3, <unused>
+ *
+ * The input frequency to the timer module for emulation is 2.5MHz which is
+ * common to all the timer channels (T1, T2, and T3). With a pre-scaler of 32,
+ * the timers are clocked at 78.125KHz (12.8 us resolution).
+ *
+ * The input frequency to the timer module in silicon will be 200MHz. With the
+ * pre-scaler of 32, the timers are clocked at 6.25MHz (160ns resolution).
+ */
+#define XTTCPSS_CLOCKSOURCE 0 /* Timer 1 as a generic timekeeping */
+#define XTTCPSS_CLOCKEVENT 1 /* Timer 2 as a clock event */
+
+#define XTTCPSS_TIMER_BASE TTC0_BASE
+#define XTTCPCC_EVENT_TIMER_IRQ (IRQ_TIMERCOUNTER0 + 1)
+/*
+ * Timer Register Offset Definitions of Timer 1, Increment base address by 4
+ * and use same offsets for Timer 2
+ */
+#define XTTCPSS_CLK_CNTRL_OFFSET 0x00 /* Clock Control Reg, RW */
+#define XTTCPSS_CNT_CNTRL_OFFSET 0x0C /* Counter Control Reg, RW */
+#define XTTCPSS_COUNT_VAL_OFFSET 0x18 /* Counter Value Reg, RO */
+#define XTTCPSS_INTR_VAL_OFFSET 0x24 /* Interval Count Reg, RW */
+#define XTTCPSS_MATCH_1_OFFSET 0x30 /* Match 1 Value Reg, RW */
+#define XTTCPSS_MATCH_2_OFFSET 0x3C /* Match 2 Value Reg, RW */
+#define XTTCPSS_MATCH_3_OFFSET 0x48 /* Match 3 Value Reg, RW */
+#define XTTCPSS_ISR_OFFSET 0x54 /* Interrupt Status Reg, RO */
+#define XTTCPSS_IER_OFFSET 0x60 /* Interrupt Enable Reg, RW */
+
+#define XTTCPSS_CNT_CNTRL_DISABLE_MASK 0x1
+
+/* Setup the timers to use pre-scaling */
+
+#define TIMER_RATE (PERIPHERAL_CLOCK_RATE / 32)
+
+/**
+ * struct xttcpss_timer - This definition defines local timer structure
+ *
+ * @base_addr: Base address of timer
+ **/
+struct xttcpss_timer {
+ void __iomem *base_addr;
+};
+
+static struct xttcpss_timer timers[2];
+static struct clock_event_device xttcpss_clockevent;
+
+/**
+ * xttcpss_set_interval - Set the timer interval value
+ *
+ * @timer: Pointer to the timer instance
+ * @cycles: Timer interval ticks
+ **/
+static void xttcpss_set_interval(struct xttcpss_timer *timer,
+ unsigned long cycles)
+{
+ u32 ctrl_reg;
+
+ /* Disable the counter, set the counter value and re-enable counter */
+ ctrl_reg = __raw_readl(timer->base_addr + XTTCPSS_CNT_CNTRL_OFFSET);
+ ctrl_reg |= XTTCPSS_CNT_CNTRL_DISABLE_MASK;
+ __raw_writel(ctrl_reg, timer->base_addr + XTTCPSS_CNT_CNTRL_OFFSET);
+
+ __raw_writel(cycles, timer->base_addr + XTTCPSS_INTR_VAL_OFFSET);
+
+ /* Reset the counter (0x10) so that it starts from 0, one-shot
+ mode makes this needed for timing to be right. */
+ ctrl_reg |= 0x10;
+ ctrl_reg &= ~XTTCPSS_CNT_CNTRL_DISABLE_MASK;
+ __raw_writel(ctrl_reg, timer->base_addr + XTTCPSS_CNT_CNTRL_OFFSET);
+}
+
+/**
+ * xttcpss_clock_event_interrupt - Clock event timer interrupt handler
+ *
+ * @irq: IRQ number of the Timer
+ * @dev_id: void pointer to the xttcpss_timer instance
+ *
+ * returns: Always IRQ_HANDLED - success
+ **/
+static irqreturn_t xttcpss_clock_event_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &xttcpss_clockevent;
+ struct xttcpss_timer *timer = dev_id;
+
+ /* Acknowledge the interrupt and call event handler */
+ __raw_writel(__raw_readl(timer->base_addr + XTTCPSS_ISR_OFFSET),
+ timer->base_addr + XTTCPSS_ISR_OFFSET);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction event_timer_irq = {
+ .name = "xttcpss clockevent",
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .handler = xttcpss_clock_event_interrupt,
+};
+
+/**
+ * xttcpss_timer_hardware_init - Initialize the timer hardware
+ *
+ * Initialize the hardware to start the clock source, get the clock
+ * event timer ready to use, and hook up the interrupt.
+ **/
+static void __init xttcpss_timer_hardware_init(void)
+{
+ /* Setup the clock source counter to be an incrementing counter
+ * with no interrupt and it rolls over at 0xFFFF. Pre-scale
+ it by 32 also. Let it start running now.
+ */
+ timers[XTTCPSS_CLOCKSOURCE].base_addr = XTTCPSS_TIMER_BASE;
+
+ __raw_writel(0x0, timers[XTTCPSS_CLOCKSOURCE].base_addr +
+ XTTCPSS_IER_OFFSET);
+ __raw_writel(0x9, timers[XTTCPSS_CLOCKSOURCE].base_addr +
+ XTTCPSS_CLK_CNTRL_OFFSET);
+ __raw_writel(0x10, timers[XTTCPSS_CLOCKSOURCE].base_addr +
+ XTTCPSS_CNT_CNTRL_OFFSET);
+
+ /* Setup the clock event timer to be an interval timer which
+ * is prescaled by 32 using the interval interrupt. Leave it
+ * disabled for now.
+ */
+
+ timers[XTTCPSS_CLOCKEVENT].base_addr = XTTCPSS_TIMER_BASE + 4;
+
+ __raw_writel(0x23, timers[XTTCPSS_CLOCKEVENT].base_addr +
+ XTTCPSS_CNT_CNTRL_OFFSET);
+ __raw_writel(0x9, timers[XTTCPSS_CLOCKEVENT].base_addr +
+ XTTCPSS_CLK_CNTRL_OFFSET);
+ __raw_writel(0x1, timers[XTTCPSS_CLOCKEVENT].base_addr +
+ XTTCPSS_IER_OFFSET);
+
+ /* Setup IRQ the clock event timer */
+ event_timer_irq.dev_id = &timers[XTTCPSS_CLOCKEVENT];
+ setup_irq(XTTCPCC_EVENT_TIMER_IRQ, &event_timer_irq);
+}
+
+/**
+ * __raw_readl_cycles - Reads the timer counter register
+ *
+ * returns: Current timer counter register value
+ **/
+static cycle_t __raw_readl_cycles(struct clocksource *cs)
+{
+ struct xttcpss_timer *timer = &timers[XTTCPSS_CLOCKSOURCE];
+
+ return (cycle_t)__raw_readl(timer->base_addr +
+ XTTCPSS_COUNT_VAL_OFFSET);
+}
+
+
+/*
+ * Instantiate and initialize the clock source structure
+ */
+static struct clocksource clocksource_xttcpss = {
+ .name = "xttcpss_timer1",
+ .rating = 200, /* Reasonable clock source */
+ .read = __raw_readl_cycles,
+ .mask = CLOCKSOURCE_MASK(16),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+
+/**
+ * xttcpss_set_next_event - Sets the time interval for next event
+ *
+ * @cycles: Timer interval ticks
+ * @evt: Address of clock event instance
+ *
+ * returns: Always 0 - success
+ **/
+static int xttcpss_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ struct xttcpss_timer *timer = &timers[XTTCPSS_CLOCKEVENT];
+
+ xttcpss_set_interval(timer, cycles);
+ return 0;
+}
+
+/**
+ * xttcpss_set_mode - Sets the mode of timer
+ *
+ * @mode: Mode to be set
+ * @evt: Address of clock event instance
+ **/
+static void xttcpss_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ struct xttcpss_timer *timer = &timers[XTTCPSS_CLOCKEVENT];
+ u32 ctrl_reg;
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ xttcpss_set_interval(timer, TIMER_RATE / HZ);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ ctrl_reg = __raw_readl(timer->base_addr +
+ XTTCPSS_CNT_CNTRL_OFFSET);
+ ctrl_reg |= XTTCPSS_CNT_CNTRL_DISABLE_MASK;
+ __raw_writel(ctrl_reg,
+ timer->base_addr + XTTCPSS_CNT_CNTRL_OFFSET);
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ ctrl_reg = __raw_readl(timer->base_addr +
+ XTTCPSS_CNT_CNTRL_OFFSET);
+ ctrl_reg &= ~XTTCPSS_CNT_CNTRL_DISABLE_MASK;
+ __raw_writel(ctrl_reg,
+ timer->base_addr + XTTCPSS_CNT_CNTRL_OFFSET);
+ break;
+ }
+}
+
+/*
+ * Instantiate and initialize the clock event structure
+ */
+static struct clock_event_device xttcpss_clockevent = {
+ .name = "xttcpss_timer2",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = xttcpss_set_next_event,
+ .set_mode = xttcpss_set_mode,
+ .rating = 200,
+};
+
+/**
+ * xttcpss_timer_init - Initialize the timer
+ *
+ * Initializes the timer hardware and register the clock source and clock event
+ * timers with Linux kernal timer framework
+ **/
+static void __init xttcpss_timer_init(void)
+{
+ xttcpss_timer_hardware_init();
+ clocksource_register_hz(&clocksource_xttcpss, TIMER_RATE);
+
+ /* Calculate the parameters to allow the clockevent to operate using
+ integer math
+ */
+ clockevents_calc_mult_shift(&xttcpss_clockevent, TIMER_RATE, 4);
+
+ xttcpss_clockevent.max_delta_ns =
+ clockevent_delta2ns(0xfffe, &xttcpss_clockevent);
+ xttcpss_clockevent.min_delta_ns =
+ clockevent_delta2ns(1, &xttcpss_clockevent);
+
+ /* Indicate that clock event is on 1st CPU as SMP boot needs it */
+
+ xttcpss_clockevent.cpumask = cpumask_of(0);
+ clockevents_register_device(&xttcpss_clockevent);
+}
+
+/*
+ * Instantiate and initialize the system timer structure
+ */
+struct sys_timer xttcpss_sys_timer = {
+ .init = xttcpss_timer_init,
+};