1 files changed, 434 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/fsl_gtm.c b/arch/powerpc/sysdev/fsl_gtm.c
new file mode 100644
index 000000000000..714ec02fed2e
--- /dev/null
+++ b/arch/powerpc/sysdev/fsl_gtm.c
@@ -0,0 +1,434 @@
+/*
+ * 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, &gtms, list_node) {
+                spin_lock_irq(&gtm->lock);
+
+                for (i = 0; i < ARRAY_SIZE(gtm->timers); i++) {
+                        if (!gtm->timers[i].requested) {
+                                gtm->timers[i].requested = true;
+                                spin_unlock_irq(&gtm->lock);
+                                return &gtm->timers[i];
+                        }
+                }
+
+                spin_unlock_irq(&gtm->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(&gtm->lock);
+
+        if (gtm->timers[timer].requested)
+                goto out;
+
+        ret = &gtm->timers[timer];
+        ret->requested = true;
+
+out:
+        spin_unlock_irq(&gtm->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 - &gtm->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(&gtm->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(&gtm->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 - &gtm->timers[0];
+        unsigned long flags;
+
+        spin_lock_irqsave(&gtm->lock, flags);
+
+        setbits8(tmr->gtcfr, GTCFR_STP(num));
+        out_be16(tmr->gtevr, 0xFFFF);
+
+        spin_unlock_irqrestore(&gtm->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 = &regs->gtcfr1;
+        timers[0].gtmdr = &regs->gtmdr1;
+        timers[0].gtcnr = &regs->gtcnr1;
+        timers[0].gtrfr = &regs->gtrfr1;
+        timers[0].gtevr = &regs->gtevr1;
+
+        timers[1].gtcfr = &regs->gtcfr1;
+        timers[1].gtmdr = &regs->gtmdr2;
+        timers[1].gtcnr = &regs->gtcnr2;
+        timers[1].gtrfr = &regs->gtrfr2;
+        timers[1].gtevr = &regs->gtevr2;
+
+        timers[2].gtcfr = &regs->gtcfr2;
+        timers[2].gtmdr = &regs->gtmdr3;
+        timers[2].gtcnr = &regs->gtcnr3;
+        timers[2].gtrfr = &regs->gtrfr3;
+        timers[2].gtevr = &regs->gtevr3;
+
+        timers[3].gtcfr = &regs->gtcfr2;
+        timers[3].gtmdr = &regs->gtmdr4;
+        timers[3].gtcnr = &regs->gtcnr4;
+        timers[3].gtrfr = &regs->gtrfr4;
+        timers[3].gtevr = &regs->gtevr4;
+
+        /* CPM2 doesn't have primary prescaler */
+        if (!of_device_is_compatible(np, "fsl,cpm2-gtm")) {
+                timers[0].gtpsr = &regs->gtpsr1;
+                timers[1].gtpsr = &regs->gtpsr2;
+                timers[2].gtpsr = &regs->gtpsr3;
+                timers[3].gtpsr = &regs->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(&gtm->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(&gtm->list_node, &gtms);
+
+                /* 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);