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Diffstat (limited to 'arch/powerpc/sysdev/mpic_timer.c')
-rw-r--r--arch/powerpc/sysdev/mpic_timer.c556
1 files changed, 556 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/mpic_timer.c b/arch/powerpc/sysdev/mpic_timer.c
new file mode 100644
index 0000000000..7166e2e0ba
--- /dev/null
+++ b/arch/powerpc/sysdev/mpic_timer.c
@@ -0,0 +1,556 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MPIC timer driver
+ *
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ * Author: Dongsheng Wang <Dongsheng.Wang@freescale.com>
+ * Li Yang <leoli@freescale.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/syscore_ops.h>
+#include <sysdev/fsl_soc.h>
+#include <asm/io.h>
+
+#include <asm/mpic_timer.h>
+
+#define FSL_GLOBAL_TIMER 0x1
+
+/* Clock Ratio
+ * Divide by 64 0x00000300
+ * Divide by 32 0x00000200
+ * Divide by 16 0x00000100
+ * Divide by 8 0x00000000 (Hardware default div)
+ */
+#define MPIC_TIMER_TCR_CLKDIV 0x00000300
+
+#define MPIC_TIMER_TCR_ROVR_OFFSET 24
+
+#define TIMER_STOP 0x80000000
+#define GTCCR_TOG 0x80000000
+#define TIMERS_PER_GROUP 4
+#define MAX_TICKS (~0U >> 1)
+#define MAX_TICKS_CASCADE (~0U)
+#define TIMER_OFFSET(num) (1 << (TIMERS_PER_GROUP - 1 - num))
+
+struct timer_regs {
+ u32 gtccr;
+ u32 res0[3];
+ u32 gtbcr;
+ u32 res1[3];
+ u32 gtvpr;
+ u32 res2[3];
+ u32 gtdr;
+ u32 res3[3];
+};
+
+struct cascade_priv {
+ u32 tcr_value; /* TCR register: CASC & ROVR value */
+ unsigned int cascade_map; /* cascade map */
+ unsigned int timer_num; /* cascade control timer */
+};
+
+struct timer_group_priv {
+ struct timer_regs __iomem *regs;
+ struct mpic_timer timer[TIMERS_PER_GROUP];
+ struct list_head node;
+ unsigned int timerfreq;
+ unsigned int idle;
+ unsigned int flags;
+ spinlock_t lock;
+ void __iomem *group_tcr;
+};
+
+static struct cascade_priv cascade_timer[] = {
+ /* cascade timer 0 and 1 */
+ {0x1, 0xc, 0x1},
+ /* cascade timer 1 and 2 */
+ {0x2, 0x6, 0x2},
+ /* cascade timer 2 and 3 */
+ {0x4, 0x3, 0x3}
+};
+
+static LIST_HEAD(timer_group_list);
+
+static void convert_ticks_to_time(struct timer_group_priv *priv,
+ const u64 ticks, time64_t *time)
+{
+ *time = (u64)div_u64(ticks, priv->timerfreq);
+}
+
+/* the time set by the user is converted to "ticks" */
+static int convert_time_to_ticks(struct timer_group_priv *priv,
+ time64_t time, u64 *ticks)
+{
+ u64 max_value; /* prevent u64 overflow */
+
+ max_value = div_u64(ULLONG_MAX, priv->timerfreq);
+
+ if (time > max_value)
+ return -EINVAL;
+
+ *ticks = (u64)time * (u64)priv->timerfreq;
+
+ return 0;
+}
+
+/* detect whether there is a cascade timer available */
+static struct mpic_timer *detect_idle_cascade_timer(
+ struct timer_group_priv *priv)
+{
+ struct cascade_priv *casc_priv;
+ unsigned int map;
+ unsigned int array_size = ARRAY_SIZE(cascade_timer);
+ unsigned int num;
+ unsigned int i;
+ unsigned long flags;
+
+ casc_priv = cascade_timer;
+ for (i = 0; i < array_size; i++) {
+ spin_lock_irqsave(&priv->lock, flags);
+ map = casc_priv->cascade_map & priv->idle;
+ if (map == casc_priv->cascade_map) {
+ num = casc_priv->timer_num;
+ priv->timer[num].cascade_handle = casc_priv;
+
+ /* set timer busy */
+ priv->idle &= ~casc_priv->cascade_map;
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return &priv->timer[num];
+ }
+ spin_unlock_irqrestore(&priv->lock, flags);
+ casc_priv++;
+ }
+
+ return NULL;
+}
+
+static int set_cascade_timer(struct timer_group_priv *priv, u64 ticks,
+ unsigned int num)
+{
+ struct cascade_priv *casc_priv;
+ u32 tcr;
+ u32 tmp_ticks;
+ u32 rem_ticks;
+
+ /* set group tcr reg for cascade */
+ casc_priv = priv->timer[num].cascade_handle;
+ if (!casc_priv)
+ return -EINVAL;
+
+ tcr = casc_priv->tcr_value |
+ (casc_priv->tcr_value << MPIC_TIMER_TCR_ROVR_OFFSET);
+ setbits32(priv->group_tcr, tcr);
+
+ tmp_ticks = div_u64_rem(ticks, MAX_TICKS_CASCADE, &rem_ticks);
+
+ out_be32(&priv->regs[num].gtccr, 0);
+ out_be32(&priv->regs[num].gtbcr, tmp_ticks | TIMER_STOP);
+
+ out_be32(&priv->regs[num - 1].gtccr, 0);
+ out_be32(&priv->regs[num - 1].gtbcr, rem_ticks);
+
+ return 0;
+}
+
+static struct mpic_timer *get_cascade_timer(struct timer_group_priv *priv,
+ u64 ticks)
+{
+ struct mpic_timer *allocated_timer;
+
+ /* Two cascade timers: Support the maximum time */
+ const u64 max_ticks = (u64)MAX_TICKS * (u64)MAX_TICKS_CASCADE;
+ int ret;
+
+ if (ticks > max_ticks)
+ return NULL;
+
+ /* detect idle timer */
+ allocated_timer = detect_idle_cascade_timer(priv);
+ if (!allocated_timer)
+ return NULL;
+
+ /* set ticks to timer */
+ ret = set_cascade_timer(priv, ticks, allocated_timer->num);
+ if (ret < 0)
+ return NULL;
+
+ return allocated_timer;
+}
+
+static struct mpic_timer *get_timer(time64_t time)
+{
+ struct timer_group_priv *priv;
+ struct mpic_timer *timer;
+
+ u64 ticks;
+ unsigned int num;
+ unsigned int i;
+ unsigned long flags;
+ int ret;
+
+ list_for_each_entry(priv, &timer_group_list, node) {
+ ret = convert_time_to_ticks(priv, time, &ticks);
+ if (ret < 0)
+ return NULL;
+
+ if (ticks > MAX_TICKS) {
+ if (!(priv->flags & FSL_GLOBAL_TIMER))
+ return NULL;
+
+ timer = get_cascade_timer(priv, ticks);
+ if (!timer)
+ continue;
+
+ return timer;
+ }
+
+ for (i = 0; i < TIMERS_PER_GROUP; i++) {
+ /* one timer: Reverse allocation */
+ num = TIMERS_PER_GROUP - 1 - i;
+ spin_lock_irqsave(&priv->lock, flags);
+ if (priv->idle & (1 << i)) {
+ /* set timer busy */
+ priv->idle &= ~(1 << i);
+ /* set ticks & stop timer */
+ out_be32(&priv->regs[num].gtbcr,
+ ticks | TIMER_STOP);
+ out_be32(&priv->regs[num].gtccr, 0);
+ priv->timer[num].cascade_handle = NULL;
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return &priv->timer[num];
+ }
+ spin_unlock_irqrestore(&priv->lock, flags);
+ }
+ }
+
+ return NULL;
+}
+
+/**
+ * mpic_start_timer - start hardware timer
+ * @handle: the timer to be started.
+ *
+ * It will do ->fn(->dev) callback from the hardware interrupt at
+ * the 'time64_t' point in the future.
+ */
+void mpic_start_timer(struct mpic_timer *handle)
+{
+ struct timer_group_priv *priv = container_of(handle,
+ struct timer_group_priv, timer[handle->num]);
+
+ clrbits32(&priv->regs[handle->num].gtbcr, TIMER_STOP);
+}
+EXPORT_SYMBOL(mpic_start_timer);
+
+/**
+ * mpic_stop_timer - stop hardware timer
+ * @handle: the timer to be stopped
+ *
+ * The timer periodically generates an interrupt. Unless user stops the timer.
+ */
+void mpic_stop_timer(struct mpic_timer *handle)
+{
+ struct timer_group_priv *priv = container_of(handle,
+ struct timer_group_priv, timer[handle->num]);
+ struct cascade_priv *casc_priv;
+
+ setbits32(&priv->regs[handle->num].gtbcr, TIMER_STOP);
+
+ casc_priv = priv->timer[handle->num].cascade_handle;
+ if (casc_priv) {
+ out_be32(&priv->regs[handle->num].gtccr, 0);
+ out_be32(&priv->regs[handle->num - 1].gtccr, 0);
+ } else {
+ out_be32(&priv->regs[handle->num].gtccr, 0);
+ }
+}
+EXPORT_SYMBOL(mpic_stop_timer);
+
+/**
+ * mpic_get_remain_time - get timer time
+ * @handle: the timer to be selected.
+ * @time: time for timer
+ *
+ * Query timer remaining time.
+ */
+void mpic_get_remain_time(struct mpic_timer *handle, time64_t *time)
+{
+ struct timer_group_priv *priv = container_of(handle,
+ struct timer_group_priv, timer[handle->num]);
+ struct cascade_priv *casc_priv;
+
+ u64 ticks;
+ u32 tmp_ticks;
+
+ casc_priv = priv->timer[handle->num].cascade_handle;
+ if (casc_priv) {
+ tmp_ticks = in_be32(&priv->regs[handle->num].gtccr);
+ tmp_ticks &= ~GTCCR_TOG;
+ ticks = ((u64)tmp_ticks & UINT_MAX) * (u64)MAX_TICKS_CASCADE;
+ tmp_ticks = in_be32(&priv->regs[handle->num - 1].gtccr);
+ ticks += tmp_ticks;
+ } else {
+ ticks = in_be32(&priv->regs[handle->num].gtccr);
+ ticks &= ~GTCCR_TOG;
+ }
+
+ convert_ticks_to_time(priv, ticks, time);
+}
+EXPORT_SYMBOL(mpic_get_remain_time);
+
+/**
+ * mpic_free_timer - free hardware timer
+ * @handle: the timer to be removed.
+ *
+ * Free the timer.
+ *
+ * Note: can not be used in interrupt context.
+ */
+void mpic_free_timer(struct mpic_timer *handle)
+{
+ struct timer_group_priv *priv = container_of(handle,
+ struct timer_group_priv, timer[handle->num]);
+
+ struct cascade_priv *casc_priv;
+ unsigned long flags;
+
+ mpic_stop_timer(handle);
+
+ casc_priv = priv->timer[handle->num].cascade_handle;
+
+ free_irq(priv->timer[handle->num].irq, priv->timer[handle->num].dev);
+
+ spin_lock_irqsave(&priv->lock, flags);
+ if (casc_priv) {
+ u32 tcr;
+ tcr = casc_priv->tcr_value | (casc_priv->tcr_value <<
+ MPIC_TIMER_TCR_ROVR_OFFSET);
+ clrbits32(priv->group_tcr, tcr);
+ priv->idle |= casc_priv->cascade_map;
+ priv->timer[handle->num].cascade_handle = NULL;
+ } else {
+ priv->idle |= TIMER_OFFSET(handle->num);
+ }
+ spin_unlock_irqrestore(&priv->lock, flags);
+}
+EXPORT_SYMBOL(mpic_free_timer);
+
+/**
+ * mpic_request_timer - get a hardware timer
+ * @fn: interrupt handler function
+ * @dev: callback function of the data
+ * @time: time for timer
+ *
+ * This executes the "request_irq", returning NULL
+ * else "handle" on success.
+ */
+struct mpic_timer *mpic_request_timer(irq_handler_t fn, void *dev,
+ time64_t time)
+{
+ struct mpic_timer *allocated_timer;
+ int ret;
+
+ if (list_empty(&timer_group_list))
+ return NULL;
+
+ if (time < 0)
+ return NULL;
+
+ allocated_timer = get_timer(time);
+ if (!allocated_timer)
+ return NULL;
+
+ ret = request_irq(allocated_timer->irq, fn,
+ IRQF_TRIGGER_LOW, "global-timer", dev);
+ if (ret) {
+ mpic_free_timer(allocated_timer);
+ return NULL;
+ }
+
+ allocated_timer->dev = dev;
+
+ return allocated_timer;
+}
+EXPORT_SYMBOL(mpic_request_timer);
+
+static int __init timer_group_get_freq(struct device_node *np,
+ struct timer_group_priv *priv)
+{
+ u32 div;
+
+ if (priv->flags & FSL_GLOBAL_TIMER) {
+ struct device_node *dn;
+
+ dn = of_find_compatible_node(NULL, NULL, "fsl,mpic");
+ if (dn) {
+ of_property_read_u32(dn, "clock-frequency",
+ &priv->timerfreq);
+ of_node_put(dn);
+ }
+ }
+
+ if (priv->timerfreq <= 0)
+ return -EINVAL;
+
+ if (priv->flags & FSL_GLOBAL_TIMER) {
+ div = (1 << (MPIC_TIMER_TCR_CLKDIV >> 8)) * 8;
+ priv->timerfreq /= div;
+ }
+
+ return 0;
+}
+
+static int __init timer_group_get_irq(struct device_node *np,
+ struct timer_group_priv *priv)
+{
+ const u32 all_timer[] = { 0, TIMERS_PER_GROUP };
+ const u32 *p;
+ u32 offset;
+ u32 count;
+
+ unsigned int i;
+ unsigned int j;
+ unsigned int irq_index = 0;
+ unsigned int irq;
+ int len;
+
+ p = of_get_property(np, "fsl,available-ranges", &len);
+ if (p && len % (2 * sizeof(u32)) != 0) {
+ pr_err("%pOF: malformed available-ranges property.\n", np);
+ return -EINVAL;
+ }
+
+ if (!p) {
+ p = all_timer;
+ len = sizeof(all_timer);
+ }
+
+ len /= 2 * sizeof(u32);
+
+ for (i = 0; i < len; i++) {
+ offset = p[i * 2];
+ count = p[i * 2 + 1];
+ for (j = 0; j < count; j++) {
+ irq = irq_of_parse_and_map(np, irq_index);
+ if (!irq) {
+ pr_err("%pOF: irq parse and map failed.\n", np);
+ return -EINVAL;
+ }
+
+ /* Set timer idle */
+ priv->idle |= TIMER_OFFSET((offset + j));
+ priv->timer[offset + j].irq = irq;
+ priv->timer[offset + j].num = offset + j;
+ irq_index++;
+ }
+ }
+
+ return 0;
+}
+
+static void __init timer_group_init(struct device_node *np)
+{
+ struct timer_group_priv *priv;
+ unsigned int i = 0;
+ int ret;
+
+ priv = kzalloc(sizeof(struct timer_group_priv), GFP_KERNEL);
+ if (!priv) {
+ pr_err("%pOF: cannot allocate memory for group.\n", np);
+ return;
+ }
+
+ if (of_device_is_compatible(np, "fsl,mpic-global-timer"))
+ priv->flags |= FSL_GLOBAL_TIMER;
+
+ priv->regs = of_iomap(np, i++);
+ if (!priv->regs) {
+ pr_err("%pOF: cannot ioremap timer register address.\n", np);
+ goto out;
+ }
+
+ if (priv->flags & FSL_GLOBAL_TIMER) {
+ priv->group_tcr = of_iomap(np, i++);
+ if (!priv->group_tcr) {
+ pr_err("%pOF: cannot ioremap tcr address.\n", np);
+ goto out;
+ }
+ }
+
+ ret = timer_group_get_freq(np, priv);
+ if (ret < 0) {
+ pr_err("%pOF: cannot get timer frequency.\n", np);
+ goto out;
+ }
+
+ ret = timer_group_get_irq(np, priv);
+ if (ret < 0) {
+ pr_err("%pOF: cannot get timer irqs.\n", np);
+ goto out;
+ }
+
+ spin_lock_init(&priv->lock);
+
+ /* Init FSL timer hardware */
+ if (priv->flags & FSL_GLOBAL_TIMER)
+ setbits32(priv->group_tcr, MPIC_TIMER_TCR_CLKDIV);
+
+ list_add_tail(&priv->node, &timer_group_list);
+
+ return;
+
+out:
+ if (priv->regs)
+ iounmap(priv->regs);
+
+ if (priv->group_tcr)
+ iounmap(priv->group_tcr);
+
+ kfree(priv);
+}
+
+static void mpic_timer_resume(void)
+{
+ struct timer_group_priv *priv;
+
+ list_for_each_entry(priv, &timer_group_list, node) {
+ /* Init FSL timer hardware */
+ if (priv->flags & FSL_GLOBAL_TIMER)
+ setbits32(priv->group_tcr, MPIC_TIMER_TCR_CLKDIV);
+ }
+}
+
+static const struct of_device_id mpic_timer_ids[] = {
+ { .compatible = "fsl,mpic-global-timer", },
+ {},
+};
+
+static struct syscore_ops mpic_timer_syscore_ops = {
+ .resume = mpic_timer_resume,
+};
+
+static int __init mpic_timer_init(void)
+{
+ struct device_node *np = NULL;
+
+ for_each_matching_node(np, mpic_timer_ids)
+ timer_group_init(np);
+
+ register_syscore_ops(&mpic_timer_syscore_ops);
+
+ if (list_empty(&timer_group_list))
+ return -ENODEV;
+
+ return 0;
+}
+subsys_initcall(mpic_timer_init);
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