diff options
Diffstat (limited to 'arch/powerpc/sysdev/mpic_timer.c')
| -rw-r--r-- | arch/powerpc/sysdev/mpic_timer.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/mpic_timer.c b/arch/powerpc/sysdev/mpic_timer.c new file mode 100644 index 000000000..87e7c4277 --- /dev/null +++ b/arch/powerpc/sysdev/mpic_timer.c @@ -0,0 +1,561 @@ +/* + * MPIC timer driver + * + * Copyright 2013 Freescale Semiconductor, Inc. + * Author: Dongsheng Wang <Dongsheng.Wang@freescale.com> + * Li Yang <leoli@freescale.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/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_device.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 stoped + * + * 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 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 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 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); |