--- /dev/null
+/*
+ * Copyright (C) 2007-2009 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * Timer COH 901 328, runs the OS timer interrupt.
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ */
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/types.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+/* Generic stuff */
+#include <asm/mach/map.h>
+#include <asm/mach/time.h>
+
+/*
+ * APP side special timer registers
+ * This timer contains four timers which can fire an interrupt each.
+ * OS (operating system) timer @ 32768 Hz
+ * DD (device driver) timer @ 1 kHz
+ * GP1 (general purpose 1) timer @ 1MHz
+ * GP2 (general purpose 2) timer @ 1MHz
+ */
+
+/* Reset OS Timer 32bit (-/W) */
+#define U300_TIMER_APP_ROST (0x0000)
+#define U300_TIMER_APP_ROST_TIMER_RESET (0x00000000)
+/* Enable OS Timer 32bit (-/W) */
+#define U300_TIMER_APP_EOST (0x0004)
+#define U300_TIMER_APP_EOST_TIMER_ENABLE (0x00000000)
+/* Disable OS Timer 32bit (-/W) */
+#define U300_TIMER_APP_DOST (0x0008)
+#define U300_TIMER_APP_DOST_TIMER_DISABLE (0x00000000)
+/* OS Timer Mode Register 32bit (-/W) */
+#define U300_TIMER_APP_SOSTM (0x000c)
+#define U300_TIMER_APP_SOSTM_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_SOSTM_MODE_ONE_SHOT (0x00000001)
+/* OS Timer Status Register 32bit (R/-) */
+#define U300_TIMER_APP_OSTS (0x0010)
+#define U300_TIMER_APP_OSTS_TIMER_STATE_MASK (0x0000000F)
+#define U300_TIMER_APP_OSTS_TIMER_STATE_IDLE (0x00000001)
+#define U300_TIMER_APP_OSTS_TIMER_STATE_ACTIVE (0x00000002)
+#define U300_TIMER_APP_OSTS_ENABLE_IND (0x00000010)
+#define U300_TIMER_APP_OSTS_MODE_MASK (0x00000020)
+#define U300_TIMER_APP_OSTS_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_OSTS_MODE_ONE_SHOT (0x00000020)
+#define U300_TIMER_APP_OSTS_IRQ_ENABLED_IND (0x00000040)
+#define U300_TIMER_APP_OSTS_IRQ_PENDING_IND (0x00000080)
+/* OS Timer Current Count Register 32bit (R/-) */
+#define U300_TIMER_APP_OSTCC (0x0014)
+/* OS Timer Terminal Count Register 32bit (R/W) */
+#define U300_TIMER_APP_OSTTC (0x0018)
+/* OS Timer Interrupt Enable Register 32bit (-/W) */
+#define U300_TIMER_APP_OSTIE (0x001c)
+#define U300_TIMER_APP_OSTIE_IRQ_DISABLE (0x00000000)
+#define U300_TIMER_APP_OSTIE_IRQ_ENABLE (0x00000001)
+/* OS Timer Interrupt Acknowledge Register 32bit (-/W) */
+#define U300_TIMER_APP_OSTIA (0x0020)
+#define U300_TIMER_APP_OSTIA_IRQ_ACK (0x00000080)
+
+/* Reset DD Timer 32bit (-/W) */
+#define U300_TIMER_APP_RDDT (0x0040)
+#define U300_TIMER_APP_RDDT_TIMER_RESET (0x00000000)
+/* Enable DD Timer 32bit (-/W) */
+#define U300_TIMER_APP_EDDT (0x0044)
+#define U300_TIMER_APP_EDDT_TIMER_ENABLE (0x00000000)
+/* Disable DD Timer 32bit (-/W) */
+#define U300_TIMER_APP_DDDT (0x0048)
+#define U300_TIMER_APP_DDDT_TIMER_DISABLE (0x00000000)
+/* DD Timer Mode Register 32bit (-/W) */
+#define U300_TIMER_APP_SDDTM (0x004c)
+#define U300_TIMER_APP_SDDTM_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_SDDTM_MODE_ONE_SHOT (0x00000001)
+/* DD Timer Status Register 32bit (R/-) */
+#define U300_TIMER_APP_DDTS (0x0050)
+#define U300_TIMER_APP_DDTS_TIMER_STATE_MASK (0x0000000F)
+#define U300_TIMER_APP_DDTS_TIMER_STATE_IDLE (0x00000001)
+#define U300_TIMER_APP_DDTS_TIMER_STATE_ACTIVE (0x00000002)
+#define U300_TIMER_APP_DDTS_ENABLE_IND (0x00000010)
+#define U300_TIMER_APP_DDTS_MODE_MASK (0x00000020)
+#define U300_TIMER_APP_DDTS_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_DDTS_MODE_ONE_SHOT (0x00000020)
+#define U300_TIMER_APP_DDTS_IRQ_ENABLED_IND (0x00000040)
+#define U300_TIMER_APP_DDTS_IRQ_PENDING_IND (0x00000080)
+/* DD Timer Current Count Register 32bit (R/-) */
+#define U300_TIMER_APP_DDTCC (0x0054)
+/* DD Timer Terminal Count Register 32bit (R/W) */
+#define U300_TIMER_APP_DDTTC (0x0058)
+/* DD Timer Interrupt Enable Register 32bit (-/W) */
+#define U300_TIMER_APP_DDTIE (0x005c)
+#define U300_TIMER_APP_DDTIE_IRQ_DISABLE (0x00000000)
+#define U300_TIMER_APP_DDTIE_IRQ_ENABLE (0x00000001)
+/* DD Timer Interrupt Acknowledge Register 32bit (-/W) */
+#define U300_TIMER_APP_DDTIA (0x0060)
+#define U300_TIMER_APP_DDTIA_IRQ_ACK (0x00000080)
+
+/* Reset GP1 Timer 32bit (-/W) */
+#define U300_TIMER_APP_RGPT1 (0x0080)
+#define U300_TIMER_APP_RGPT1_TIMER_RESET (0x00000000)
+/* Enable GP1 Timer 32bit (-/W) */
+#define U300_TIMER_APP_EGPT1 (0x0084)
+#define U300_TIMER_APP_EGPT1_TIMER_ENABLE (0x00000000)
+/* Disable GP1 Timer 32bit (-/W) */
+#define U300_TIMER_APP_DGPT1 (0x0088)
+#define U300_TIMER_APP_DGPT1_TIMER_DISABLE (0x00000000)
+/* GP1 Timer Mode Register 32bit (-/W) */
+#define U300_TIMER_APP_SGPT1M (0x008c)
+#define U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT (0x00000001)
+/* GP1 Timer Status Register 32bit (R/-) */
+#define U300_TIMER_APP_GPT1S (0x0090)
+#define U300_TIMER_APP_GPT1S_TIMER_STATE_MASK (0x0000000F)
+#define U300_TIMER_APP_GPT1S_TIMER_STATE_IDLE (0x00000001)
+#define U300_TIMER_APP_GPT1S_TIMER_STATE_ACTIVE (0x00000002)
+#define U300_TIMER_APP_GPT1S_ENABLE_IND (0x00000010)
+#define U300_TIMER_APP_GPT1S_MODE_MASK (0x00000020)
+#define U300_TIMER_APP_GPT1S_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_GPT1S_MODE_ONE_SHOT (0x00000020)
+#define U300_TIMER_APP_GPT1S_IRQ_ENABLED_IND (0x00000040)
+#define U300_TIMER_APP_GPT1S_IRQ_PENDING_IND (0x00000080)
+/* GP1 Timer Current Count Register 32bit (R/-) */
+#define U300_TIMER_APP_GPT1CC (0x0094)
+/* GP1 Timer Terminal Count Register 32bit (R/W) */
+#define U300_TIMER_APP_GPT1TC (0x0098)
+/* GP1 Timer Interrupt Enable Register 32bit (-/W) */
+#define U300_TIMER_APP_GPT1IE (0x009c)
+#define U300_TIMER_APP_GPT1IE_IRQ_DISABLE (0x00000000)
+#define U300_TIMER_APP_GPT1IE_IRQ_ENABLE (0x00000001)
+/* GP1 Timer Interrupt Acknowledge Register 32bit (-/W) */
+#define U300_TIMER_APP_GPT1IA (0x00a0)
+#define U300_TIMER_APP_GPT1IA_IRQ_ACK (0x00000080)
+
+/* Reset GP2 Timer 32bit (-/W) */
+#define U300_TIMER_APP_RGPT2 (0x00c0)
+#define U300_TIMER_APP_RGPT2_TIMER_RESET (0x00000000)
+/* Enable GP2 Timer 32bit (-/W) */
+#define U300_TIMER_APP_EGPT2 (0x00c4)
+#define U300_TIMER_APP_EGPT2_TIMER_ENABLE (0x00000000)
+/* Disable GP2 Timer 32bit (-/W) */
+#define U300_TIMER_APP_DGPT2 (0x00c8)
+#define U300_TIMER_APP_DGPT2_TIMER_DISABLE (0x00000000)
+/* GP2 Timer Mode Register 32bit (-/W) */
+#define U300_TIMER_APP_SGPT2M (0x00cc)
+#define U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_SGPT2M_MODE_ONE_SHOT (0x00000001)
+/* GP2 Timer Status Register 32bit (R/-) */
+#define U300_TIMER_APP_GPT2S (0x00d0)
+#define U300_TIMER_APP_GPT2S_TIMER_STATE_MASK (0x0000000F)
+#define U300_TIMER_APP_GPT2S_TIMER_STATE_IDLE (0x00000001)
+#define U300_TIMER_APP_GPT2S_TIMER_STATE_ACTIVE (0x00000002)
+#define U300_TIMER_APP_GPT2S_ENABLE_IND (0x00000010)
+#define U300_TIMER_APP_GPT2S_MODE_MASK (0x00000020)
+#define U300_TIMER_APP_GPT2S_MODE_CONTINUOUS (0x00000000)
+#define U300_TIMER_APP_GPT2S_MODE_ONE_SHOT (0x00000020)
+#define U300_TIMER_APP_GPT2S_IRQ_ENABLED_IND (0x00000040)
+#define U300_TIMER_APP_GPT2S_IRQ_PENDING_IND (0x00000080)
+/* GP2 Timer Current Count Register 32bit (R/-) */
+#define U300_TIMER_APP_GPT2CC (0x00d4)
+/* GP2 Timer Terminal Count Register 32bit (R/W) */
+#define U300_TIMER_APP_GPT2TC (0x00d8)
+/* GP2 Timer Interrupt Enable Register 32bit (-/W) */
+#define U300_TIMER_APP_GPT2IE (0x00dc)
+#define U300_TIMER_APP_GPT2IE_IRQ_DISABLE (0x00000000)
+#define U300_TIMER_APP_GPT2IE_IRQ_ENABLE (0x00000001)
+/* GP2 Timer Interrupt Acknowledge Register 32bit (-/W) */
+#define U300_TIMER_APP_GPT2IA (0x00e0)
+#define U300_TIMER_APP_GPT2IA_IRQ_ACK (0x00000080)
+
+/* Clock request control register - all four timers */
+#define U300_TIMER_APP_CRC (0x100)
+#define U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE (0x00000001)
+
+static void __iomem *u300_timer_base;
+
+struct u300_clockevent_data {
+ struct clock_event_device cevd;
+ unsigned ticks_per_jiffy;
+};
+
+/*
+ * The u300_set_mode() function is always called first, if we
+ * have oneshot timer active, the oneshot scheduling function
+ * u300_set_next_event() is called immediately after.
+ */
+static void u300_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ struct u300_clockevent_data *cevdata =
+ container_of(evt, struct u300_clockevent_data, cevd);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ /* Disable interrupts on GPT1 */
+ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
+ u300_timer_base + U300_TIMER_APP_GPT1IE);
+ /* Disable GP1 while we're reprogramming it. */
+ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
+ u300_timer_base + U300_TIMER_APP_DGPT1);
+ /*
+ * Set the periodic mode to a certain number of ticks per
+ * jiffy.
+ */
+ writel(cevdata->ticks_per_jiffy,
+ u300_timer_base + U300_TIMER_APP_GPT1TC);
+ /*
+ * Set continuous mode, so the timer keeps triggering
+ * interrupts.
+ */
+ writel(U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS,
+ u300_timer_base + U300_TIMER_APP_SGPT1M);
+ /* Enable timer interrupts */
+ writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
+ u300_timer_base + U300_TIMER_APP_GPT1IE);
+ /* Then enable the OS timer again */
+ writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
+ u300_timer_base + U300_TIMER_APP_EGPT1);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* Just break; here? */
+ /*
+ * The actual event will be programmed by the next event hook,
+ * so we just set a dummy value somewhere at the end of the
+ * universe here.
+ */
+ /* Disable interrupts on GPT1 */
+ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
+ u300_timer_base + U300_TIMER_APP_GPT1IE);
+ /* Disable GP1 while we're reprogramming it. */
+ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
+ u300_timer_base + U300_TIMER_APP_DGPT1);
+ /*
+ * Expire far in the future, u300_set_next_event() will be
+ * called soon...
+ */
+ writel(0xFFFFFFFF, u300_timer_base + U300_TIMER_APP_GPT1TC);
+ /* We run one shot per tick here! */
+ writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,
+ u300_timer_base + U300_TIMER_APP_SGPT1M);
+ /* Enable interrupts for this timer */
+ writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
+ u300_timer_base + U300_TIMER_APP_GPT1IE);
+ /* Enable timer */
+ writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
+ u300_timer_base + U300_TIMER_APP_EGPT1);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ /* Disable interrupts on GP1 */
+ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
+ u300_timer_base + U300_TIMER_APP_GPT1IE);
+ /* Disable GP1 */
+ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
+ u300_timer_base + U300_TIMER_APP_DGPT1);
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ /* Ignore this call */
+ break;
+ }
+}
+
+/*
+ * The app timer in one shot mode obviously has to be reprogrammed
+ * in EXACTLY this sequence to work properly. Do NOT try to e.g. replace
+ * the interrupt disable + timer disable commands with a reset command,
+ * it will fail miserably. Apparently (and I found this the hard way)
+ * the timer is very sensitive to the instruction order, though you don't
+ * get that impression from the data sheet.
+ */
+static int u300_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+
+{
+ /* Disable interrupts on GPT1 */
+ writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
+ u300_timer_base + U300_TIMER_APP_GPT1IE);
+ /* Disable GP1 while we're reprogramming it. */
+ writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
+ u300_timer_base + U300_TIMER_APP_DGPT1);
+ /* Reset the General Purpose timer 1. */
+ writel(U300_TIMER_APP_RGPT1_TIMER_RESET,
+ u300_timer_base + U300_TIMER_APP_RGPT1);
+ /* IRQ in n * cycles */
+ writel(cycles, u300_timer_base + U300_TIMER_APP_GPT1TC);
+ /*
+ * We run one shot per tick here! (This is necessary to reconfigure,
+ * the timer will tilt if you don't!)
+ */
+ writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,
+ u300_timer_base + U300_TIMER_APP_SGPT1M);
+ /* Enable timer interrupts */
+ writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
+ u300_timer_base + U300_TIMER_APP_GPT1IE);
+ /* Then enable the OS timer again */
+ writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
+ u300_timer_base + U300_TIMER_APP_EGPT1);
+ return 0;
+}
+
+static struct u300_clockevent_data u300_clockevent_data = {
+ /* Use general purpose timer 1 as clock event */
+ .cevd = {
+ .name = "GPT1",
+ /* Reasonably fast and accurate clock event */
+ .rating = 300,
+ .features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = u300_set_next_event,
+ .set_mode = u300_set_mode,
+ },
+};
+
+/* Clock event timer interrupt handler */
+static irqreturn_t u300_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &u300_clockevent_data.cevd;
+ /* ACK/Clear timer IRQ for the APP GPT1 Timer */
+
+ writel(U300_TIMER_APP_GPT1IA_IRQ_ACK,
+ u300_timer_base + U300_TIMER_APP_GPT1IA);
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction u300_timer_irq = {
+ .name = "U300 Timer Tick",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = u300_timer_interrupt,
+};
+
+/*
+ * Override the global weak sched_clock symbol with this
+ * local implementation which uses the clocksource to get some
+ * better resolution when scheduling the kernel. We accept that
+ * this wraps around for now, since it is just a relative time
+ * stamp. (Inspired by OMAP implementation.)
+ */
+
+static u64 notrace u300_read_sched_clock(void)
+{
+ return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);
+}
+
+static unsigned long u300_read_current_timer(void)
+{
+ return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);
+}
+
+static struct delay_timer u300_delay_timer;
+
+/*
+ * This sets up the system timers, clock source and clock event.
+ */
+static void __init u300_timer_init_of(struct device_node *np)
+{
+ unsigned int irq;
+ struct clk *clk;
+ unsigned long rate;
+
+ u300_timer_base = of_iomap(np, 0);
+ if (!u300_timer_base)
+ panic("could not ioremap system timer\n");
+
+ /* Get the IRQ for the GP1 timer */
+ irq = irq_of_parse_and_map(np, 2);
+ if (!irq)
+ panic("no IRQ for system timer\n");
+
+ pr_info("U300 GP1 timer @ base: %p, IRQ: %u\n", u300_timer_base, irq);
+
+ /* Clock the interrupt controller */
+ clk = of_clk_get(np, 0);
+ BUG_ON(IS_ERR(clk));
+ clk_prepare_enable(clk);
+ rate = clk_get_rate(clk);
+
+ u300_clockevent_data.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
+
+ sched_clock_register(u300_read_sched_clock, 32, rate);
+
+ u300_delay_timer.read_current_timer = &u300_read_current_timer;
+ u300_delay_timer.freq = rate;
+ register_current_timer_delay(&u300_delay_timer);
+
+ /*
+ * Disable the "OS" and "DD" timers - these are designed for Symbian!
+ * Example usage in cnh1601578 cpu subsystem pd_timer_app.c
+ */
+ writel(U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE,
+ u300_timer_base + U300_TIMER_APP_CRC);
+ writel(U300_TIMER_APP_ROST_TIMER_RESET,
+ u300_timer_base + U300_TIMER_APP_ROST);
+ writel(U300_TIMER_APP_DOST_TIMER_DISABLE,
+ u300_timer_base + U300_TIMER_APP_DOST);
+ writel(U300_TIMER_APP_RDDT_TIMER_RESET,
+ u300_timer_base + U300_TIMER_APP_RDDT);
+ writel(U300_TIMER_APP_DDDT_TIMER_DISABLE,
+ u300_timer_base + U300_TIMER_APP_DDDT);
+
+ /* Reset the General Purpose timer 1. */
+ writel(U300_TIMER_APP_RGPT1_TIMER_RESET,
+ u300_timer_base + U300_TIMER_APP_RGPT1);
+
+ /* Set up the IRQ handler */
+ setup_irq(irq, &u300_timer_irq);
+
+ /* Reset the General Purpose timer 2 */
+ writel(U300_TIMER_APP_RGPT2_TIMER_RESET,
+ u300_timer_base + U300_TIMER_APP_RGPT2);
+ /* Set this timer to run around forever */
+ writel(0xFFFFFFFFU, u300_timer_base + U300_TIMER_APP_GPT2TC);
+ /* Set continuous mode so it wraps around */
+ writel(U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS,
+ u300_timer_base + U300_TIMER_APP_SGPT2M);
+ /* Disable timer interrupts */
+ writel(U300_TIMER_APP_GPT2IE_IRQ_DISABLE,
+ u300_timer_base + U300_TIMER_APP_GPT2IE);
+ /* Then enable the GP2 timer to use as a free running us counter */
+ writel(U300_TIMER_APP_EGPT2_TIMER_ENABLE,
+ u300_timer_base + U300_TIMER_APP_EGPT2);
+
+ /* Use general purpose timer 2 as clock source */
+ if (clocksource_mmio_init(u300_timer_base + U300_TIMER_APP_GPT2CC,
+ "GPT2", rate, 300, 32, clocksource_mmio_readl_up))
+ pr_err("timer: failed to initialize U300 clock source\n");
+
+ /* Configure and register the clockevent */
+ clockevents_config_and_register(&u300_clockevent_data.cevd, rate,
+ 1, 0xffffffff);
+
+ /*
+ * TODO: init and register the rest of the timers too, they can be
+ * used by hrtimers!
+ */
+}
+
+CLOCKSOURCE_OF_DECLARE(u300_timer, "stericsson,u300-apptimer",
+ u300_timer_init_of);
Code Review / kvmfornfv.git / blobdiff