--- /dev/null
+/*
+ * Freescale General-purpose Timers Module
+ *
+ * Copyright (c) Freescale Semicondutor, Inc. 2006.
+ * Shlomi Gridish <gridish@freescale.com>
+ * Jerry Huang <Chang-Ming.Huang@freescale.com>
+ * Copyright (c) MontaVista Software, Inc. 2008.
+ * Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/bitops.h>
+#include <asm/fsl_gtm.h>
+
+#define GTCFR_STP(x) ((x) & 1 ? 1 << 5 : 1 << 1)
+#define GTCFR_RST(x) ((x) & 1 ? 1 << 4 : 1 << 0)
+
+#define GTMDR_ICLK_MASK (3 << 1)
+#define GTMDR_ICLK_ICAS (0 << 1)
+#define GTMDR_ICLK_ICLK (1 << 1)
+#define GTMDR_ICLK_SLGO (2 << 1)
+#define GTMDR_FRR (1 << 3)
+#define GTMDR_ORI (1 << 4)
+#define GTMDR_SPS(x) ((x) << 8)
+
+struct gtm_timers_regs {
+ u8 gtcfr1; /* Timer 1, Timer 2 global config register */
+ u8 res0[0x3];
+ u8 gtcfr2; /* Timer 3, timer 4 global config register */
+ u8 res1[0xB];
+ __be16 gtmdr1; /* Timer 1 mode register */
+ __be16 gtmdr2; /* Timer 2 mode register */
+ __be16 gtrfr1; /* Timer 1 reference register */
+ __be16 gtrfr2; /* Timer 2 reference register */
+ __be16 gtcpr1; /* Timer 1 capture register */
+ __be16 gtcpr2; /* Timer 2 capture register */
+ __be16 gtcnr1; /* Timer 1 counter */
+ __be16 gtcnr2; /* Timer 2 counter */
+ __be16 gtmdr3; /* Timer 3 mode register */
+ __be16 gtmdr4; /* Timer 4 mode register */
+ __be16 gtrfr3; /* Timer 3 reference register */
+ __be16 gtrfr4; /* Timer 4 reference register */
+ __be16 gtcpr3; /* Timer 3 capture register */
+ __be16 gtcpr4; /* Timer 4 capture register */
+ __be16 gtcnr3; /* Timer 3 counter */
+ __be16 gtcnr4; /* Timer 4 counter */
+ __be16 gtevr1; /* Timer 1 event register */
+ __be16 gtevr2; /* Timer 2 event register */
+ __be16 gtevr3; /* Timer 3 event register */
+ __be16 gtevr4; /* Timer 4 event register */
+ __be16 gtpsr1; /* Timer 1 prescale register */
+ __be16 gtpsr2; /* Timer 2 prescale register */
+ __be16 gtpsr3; /* Timer 3 prescale register */
+ __be16 gtpsr4; /* Timer 4 prescale register */
+ u8 res2[0x40];
+} __attribute__ ((packed));
+
+struct gtm {
+ unsigned int clock;
+ struct gtm_timers_regs __iomem *regs;
+ struct gtm_timer timers[4];
+ spinlock_t lock;
+ struct list_head list_node;
+};
+
+static LIST_HEAD(gtms);
+
+/**
+ * gtm_get_timer - request GTM timer to use it with the rest of GTM API
+ * Context: non-IRQ
+ *
+ * This function reserves GTM timer for later use. It returns gtm_timer
+ * structure to use with the rest of GTM API, you should use timer->irq
+ * to manage timer interrupt.
+ */
+struct gtm_timer *gtm_get_timer16(void)
+{
+ struct gtm *gtm = NULL;
+ int i;
+
+ list_for_each_entry(gtm, >ms, list_node) {
+ spin_lock_irq(>m->lock);
+
+ for (i = 0; i < ARRAY_SIZE(gtm->timers); i++) {
+ if (!gtm->timers[i].requested) {
+ gtm->timers[i].requested = true;
+ spin_unlock_irq(>m->lock);
+ return >m->timers[i];
+ }
+ }
+
+ spin_unlock_irq(>m->lock);
+ }
+
+ if (gtm)
+ return ERR_PTR(-EBUSY);
+ return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL(gtm_get_timer16);
+
+/**
+ * gtm_get_specific_timer - request specific GTM timer
+ * @gtm: specific GTM, pass here GTM's device_node->data
+ * @timer: specific timer number, Timer1 is 0.
+ * Context: non-IRQ
+ *
+ * This function reserves GTM timer for later use. It returns gtm_timer
+ * structure to use with the rest of GTM API, you should use timer->irq
+ * to manage timer interrupt.
+ */
+struct gtm_timer *gtm_get_specific_timer16(struct gtm *gtm,
+ unsigned int timer)
+{
+ struct gtm_timer *ret = ERR_PTR(-EBUSY);
+
+ if (timer > 3)
+ return ERR_PTR(-EINVAL);
+
+ spin_lock_irq(>m->lock);
+
+ if (gtm->timers[timer].requested)
+ goto out;
+
+ ret = >m->timers[timer];
+ ret->requested = true;
+
+out:
+ spin_unlock_irq(>m->lock);
+ return ret;
+}
+EXPORT_SYMBOL(gtm_get_specific_timer16);
+
+/**
+ * gtm_put_timer16 - release 16 bits GTM timer
+ * @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
+ * Context: any
+ *
+ * This function releases GTM timer so others may request it.
+ */
+void gtm_put_timer16(struct gtm_timer *tmr)
+{
+ gtm_stop_timer16(tmr);
+
+ spin_lock_irq(&tmr->gtm->lock);
+ tmr->requested = false;
+ spin_unlock_irq(&tmr->gtm->lock);
+}
+EXPORT_SYMBOL(gtm_put_timer16);
+
+/*
+ * This is back-end for the exported functions, it's used to reset single
+ * timer in reference mode.
+ */
+static int gtm_set_ref_timer16(struct gtm_timer *tmr, int frequency,
+ int reference_value, bool free_run)
+{
+ struct gtm *gtm = tmr->gtm;
+ int num = tmr - >m->timers[0];
+ unsigned int prescaler;
+ u8 iclk = GTMDR_ICLK_ICLK;
+ u8 psr;
+ u8 sps;
+ unsigned long flags;
+ int max_prescaler = 256 * 256 * 16;
+
+ /* CPM2 doesn't have primary prescaler */
+ if (!tmr->gtpsr)
+ max_prescaler /= 256;
+
+ prescaler = gtm->clock / frequency;
+ /*
+ * We have two 8 bit prescalers -- primary and secondary (psr, sps),
+ * plus "slow go" mode (clk / 16). So, total prescale value is
+ * 16 * (psr + 1) * (sps + 1). Though, for CPM2 GTMs we losing psr.
+ */
+ if (prescaler > max_prescaler)
+ return -EINVAL;
+
+ if (prescaler > max_prescaler / 16) {
+ iclk = GTMDR_ICLK_SLGO;
+ prescaler /= 16;
+ }
+
+ if (prescaler <= 256) {
+ psr = 0;
+ sps = prescaler - 1;
+ } else {
+ psr = 256 - 1;
+ sps = prescaler / 256 - 1;
+ }
+
+ spin_lock_irqsave(>m->lock, flags);
+
+ /*
+ * Properly reset timers: stop, reset, set up prescalers, reference
+ * value and clear event register.
+ */
+ clrsetbits_8(tmr->gtcfr, ~(GTCFR_STP(num) | GTCFR_RST(num)),
+ GTCFR_STP(num) | GTCFR_RST(num));
+
+ setbits8(tmr->gtcfr, GTCFR_STP(num));
+
+ if (tmr->gtpsr)
+ out_be16(tmr->gtpsr, psr);
+ clrsetbits_be16(tmr->gtmdr, 0xFFFF, iclk | GTMDR_SPS(sps) |
+ GTMDR_ORI | (free_run ? GTMDR_FRR : 0));
+ out_be16(tmr->gtcnr, 0);
+ out_be16(tmr->gtrfr, reference_value);
+ out_be16(tmr->gtevr, 0xFFFF);
+
+ /* Let it be. */
+ clrbits8(tmr->gtcfr, GTCFR_STP(num));
+
+ spin_unlock_irqrestore(>m->lock, flags);
+
+ return 0;
+}
+
+/**
+ * gtm_set_timer16 - (re)set 16 bit timer with arbitrary precision
+ * @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
+ * @usec: timer interval in microseconds
+ * @reload: if set, the timer will reset upon expiry rather than
+ * continue running free.
+ * Context: any
+ *
+ * This function (re)sets the GTM timer so that it counts up to the requested
+ * interval value, and fires the interrupt when the value is reached. This
+ * function will reduce the precision of the timer as needed in order for the
+ * requested timeout to fit in a 16-bit register.
+ */
+int gtm_set_timer16(struct gtm_timer *tmr, unsigned long usec, bool reload)
+{
+ /* quite obvious, frequency which is enough for µSec precision */
+ int freq = 1000000;
+ unsigned int bit;
+
+ bit = fls_long(usec);
+ if (bit > 15) {
+ freq >>= bit - 15;
+ usec >>= bit - 15;
+ }
+
+ if (!freq)
+ return -EINVAL;
+
+ return gtm_set_ref_timer16(tmr, freq, usec, reload);
+}
+EXPORT_SYMBOL(gtm_set_timer16);
+
+/**
+ * gtm_set_exact_utimer16 - (re)set 16 bits timer
+ * @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
+ * @usec: timer interval in microseconds
+ * @reload: if set, the timer will reset upon expiry rather than
+ * continue running free.
+ * Context: any
+ *
+ * This function (re)sets GTM timer so that it counts up to the requested
+ * interval value, and fires the interrupt when the value is reached. If reload
+ * flag was set, timer will also reset itself upon reference value, otherwise
+ * it continues to increment.
+ *
+ * The _exact_ bit in the function name states that this function will not
+ * crop precision of the "usec" argument, thus usec is limited to 16 bits
+ * (single timer width).
+ */
+int gtm_set_exact_timer16(struct gtm_timer *tmr, u16 usec, bool reload)
+{
+ /* quite obvious, frequency which is enough for µSec precision */
+ const int freq = 1000000;
+
+ /*
+ * We can lower the frequency (and probably power consumption) by
+ * dividing both frequency and usec by 2 until there is no remainder.
+ * But we won't bother with this unless savings are measured, so just
+ * run the timer as is.
+ */
+
+ return gtm_set_ref_timer16(tmr, freq, usec, reload);
+}
+EXPORT_SYMBOL(gtm_set_exact_timer16);
+
+/**
+ * gtm_stop_timer16 - stop single timer
+ * @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
+ * Context: any
+ *
+ * This function simply stops the GTM timer.
+ */
+void gtm_stop_timer16(struct gtm_timer *tmr)
+{
+ struct gtm *gtm = tmr->gtm;
+ int num = tmr - >m->timers[0];
+ unsigned long flags;
+
+ spin_lock_irqsave(>m->lock, flags);
+
+ setbits8(tmr->gtcfr, GTCFR_STP(num));
+ out_be16(tmr->gtevr, 0xFFFF);
+
+ spin_unlock_irqrestore(>m->lock, flags);
+}
+EXPORT_SYMBOL(gtm_stop_timer16);
+
+/**
+ * gtm_ack_timer16 - acknowledge timer event (free-run timers only)
+ * @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
+ * @events: events mask to ack
+ * Context: any
+ *
+ * Thus function used to acknowledge timer interrupt event, use it inside the
+ * interrupt handler.
+ */
+void gtm_ack_timer16(struct gtm_timer *tmr, u16 events)
+{
+ out_be16(tmr->gtevr, events);
+}
+EXPORT_SYMBOL(gtm_ack_timer16);
+
+static void __init gtm_set_shortcuts(struct device_node *np,
+ struct gtm_timer *timers,
+ struct gtm_timers_regs __iomem *regs)
+{
+ /*
+ * Yeah, I don't like this either, but timers' registers a bit messed,
+ * so we have to provide shortcuts to write timer independent code.
+ * Alternative option is to create gt*() accessors, but that will be
+ * even uglier and cryptic.
+ */
+ timers[0].gtcfr = ®s->gtcfr1;
+ timers[0].gtmdr = ®s->gtmdr1;
+ timers[0].gtcnr = ®s->gtcnr1;
+ timers[0].gtrfr = ®s->gtrfr1;
+ timers[0].gtevr = ®s->gtevr1;
+
+ timers[1].gtcfr = ®s->gtcfr1;
+ timers[1].gtmdr = ®s->gtmdr2;
+ timers[1].gtcnr = ®s->gtcnr2;
+ timers[1].gtrfr = ®s->gtrfr2;
+ timers[1].gtevr = ®s->gtevr2;
+
+ timers[2].gtcfr = ®s->gtcfr2;
+ timers[2].gtmdr = ®s->gtmdr3;
+ timers[2].gtcnr = ®s->gtcnr3;
+ timers[2].gtrfr = ®s->gtrfr3;
+ timers[2].gtevr = ®s->gtevr3;
+
+ timers[3].gtcfr = ®s->gtcfr2;
+ timers[3].gtmdr = ®s->gtmdr4;
+ timers[3].gtcnr = ®s->gtcnr4;
+ timers[3].gtrfr = ®s->gtrfr4;
+ timers[3].gtevr = ®s->gtevr4;
+
+ /* CPM2 doesn't have primary prescaler */
+ if (!of_device_is_compatible(np, "fsl,cpm2-gtm")) {
+ timers[0].gtpsr = ®s->gtpsr1;
+ timers[1].gtpsr = ®s->gtpsr2;
+ timers[2].gtpsr = ®s->gtpsr3;
+ timers[3].gtpsr = ®s->gtpsr4;
+ }
+}
+
+static int __init fsl_gtm_init(void)
+{
+ struct device_node *np;
+
+ for_each_compatible_node(np, NULL, "fsl,gtm") {
+ int i;
+ struct gtm *gtm;
+ const u32 *clock;
+ int size;
+
+ gtm = kzalloc(sizeof(*gtm), GFP_KERNEL);
+ if (!gtm) {
+ pr_err("%s: unable to allocate memory\n",
+ np->full_name);
+ continue;
+ }
+
+ spin_lock_init(>m->lock);
+
+ clock = of_get_property(np, "clock-frequency", &size);
+ if (!clock || size != sizeof(*clock)) {
+ pr_err("%s: no clock-frequency\n", np->full_name);
+ goto err;
+ }
+ gtm->clock = *clock;
+
+ for (i = 0; i < ARRAY_SIZE(gtm->timers); i++) {
+ int ret;
+ struct resource irq;
+
+ ret = of_irq_to_resource(np, i, &irq);
+ if (ret == NO_IRQ) {
+ pr_err("%s: not enough interrupts specified\n",
+ np->full_name);
+ goto err;
+ }
+ gtm->timers[i].irq = irq.start;
+ gtm->timers[i].gtm = gtm;
+ }
+
+ gtm->regs = of_iomap(np, 0);
+ if (!gtm->regs) {
+ pr_err("%s: unable to iomap registers\n",
+ np->full_name);
+ goto err;
+ }
+
+ gtm_set_shortcuts(np, gtm->timers, gtm->regs);
+ list_add(>m->list_node, >ms);
+
+ /* We don't want to lose the node and its ->data */
+ np->data = gtm;
+ of_node_get(np);
+
+ continue;
+err:
+ kfree(gtm);
+ }
+ return 0;
+}
+arch_initcall(fsl_gtm_init);
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