linux/drivers/ptp/ptp_ixp46x.c
Richard Cochran 1ef761582c ptp: link the phc device to its parent device
PTP Hardware Clock devices appear as class devices in sysfs. This patch
changes the registration API to use the parent device, clarifying the
clock's relationship to the underlying device.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-22 15:42:38 -04:00

336 lines
7.3 KiB
C

/*
* PTP 1588 clock using the IXP46X
*
* Copyright (C) 2010 OMICRON electronics GmbH
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ptp_clock_kernel.h>
#include <mach/ixp46x_ts.h>
#define DRIVER "ptp_ixp46x"
#define N_EXT_TS 2
#define MASTER_GPIO 8
#define MASTER_IRQ 25
#define SLAVE_GPIO 7
#define SLAVE_IRQ 24
struct ixp_clock {
struct ixp46x_ts_regs *regs;
struct ptp_clock *ptp_clock;
struct ptp_clock_info caps;
int exts0_enabled;
int exts1_enabled;
};
DEFINE_SPINLOCK(register_lock);
/*
* Register access functions
*/
static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
{
u64 ns;
u32 lo, hi;
lo = __raw_readl(&regs->systime_lo);
hi = __raw_readl(&regs->systime_hi);
ns = ((u64) hi) << 32;
ns |= lo;
ns <<= TICKS_NS_SHIFT;
return ns;
}
static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
{
u32 hi, lo;
ns >>= TICKS_NS_SHIFT;
hi = ns >> 32;
lo = ns & 0xffffffff;
__raw_writel(lo, &regs->systime_lo);
__raw_writel(hi, &regs->systime_hi);
}
/*
* Interrupt service routine
*/
static irqreturn_t isr(int irq, void *priv)
{
struct ixp_clock *ixp_clock = priv;
struct ixp46x_ts_regs *regs = ixp_clock->regs;
struct ptp_clock_event event;
u32 ack = 0, lo, hi, val;
val = __raw_readl(&regs->event);
if (val & TSER_SNS) {
ack |= TSER_SNS;
if (ixp_clock->exts0_enabled) {
hi = __raw_readl(&regs->asms_hi);
lo = __raw_readl(&regs->asms_lo);
event.type = PTP_CLOCK_EXTTS;
event.index = 0;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
event.timestamp <<= TICKS_NS_SHIFT;
ptp_clock_event(ixp_clock->ptp_clock, &event);
}
}
if (val & TSER_SNM) {
ack |= TSER_SNM;
if (ixp_clock->exts1_enabled) {
hi = __raw_readl(&regs->amms_hi);
lo = __raw_readl(&regs->amms_lo);
event.type = PTP_CLOCK_EXTTS;
event.index = 1;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
event.timestamp <<= TICKS_NS_SHIFT;
ptp_clock_event(ixp_clock->ptp_clock, &event);
}
}
if (val & TTIPEND)
ack |= TTIPEND; /* this bit seems to be always set */
if (ack) {
__raw_writel(ack, &regs->event);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
/*
* PTP clock operations
*/
static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
u64 adj;
u32 diff, addend;
int neg_adj = 0;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
if (ppb < 0) {
neg_adj = 1;
ppb = -ppb;
}
addend = DEFAULT_ADDEND;
adj = addend;
adj *= ppb;
diff = div_u64(adj, 1000000000ULL);
addend = neg_adj ? addend - diff : addend + diff;
__raw_writel(addend, &regs->addend);
return 0;
}
static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
s64 now;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
spin_lock_irqsave(&register_lock, flags);
now = ixp_systime_read(regs);
now += delta;
ixp_systime_write(regs, now);
spin_unlock_irqrestore(&register_lock, flags);
return 0;
}
static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
{
u64 ns;
u32 remainder;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
spin_lock_irqsave(&register_lock, flags);
ns = ixp_systime_read(regs);
spin_unlock_irqrestore(&register_lock, flags);
ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
ts->tv_nsec = remainder;
return 0;
}
static int ptp_ixp_settime(struct ptp_clock_info *ptp,
const struct timespec *ts)
{
u64 ns;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
ns = ts->tv_sec * 1000000000ULL;
ns += ts->tv_nsec;
spin_lock_irqsave(&register_lock, flags);
ixp_systime_write(regs, ns);
spin_unlock_irqrestore(&register_lock, flags);
return 0;
}
static int ptp_ixp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
switch (rq->type) {
case PTP_CLK_REQ_EXTTS:
switch (rq->extts.index) {
case 0:
ixp_clock->exts0_enabled = on ? 1 : 0;
break;
case 1:
ixp_clock->exts1_enabled = on ? 1 : 0;
break;
default:
return -EINVAL;
}
return 0;
default:
break;
}
return -EOPNOTSUPP;
}
static struct ptp_clock_info ptp_ixp_caps = {
.owner = THIS_MODULE,
.name = "IXP46X timer",
.max_adj = 66666655,
.n_ext_ts = N_EXT_TS,
.pps = 0,
.adjfreq = ptp_ixp_adjfreq,
.adjtime = ptp_ixp_adjtime,
.gettime = ptp_ixp_gettime,
.settime = ptp_ixp_settime,
.enable = ptp_ixp_enable,
};
/* module operations */
static struct ixp_clock ixp_clock;
static int setup_interrupt(int gpio)
{
int irq;
gpio_line_config(gpio, IXP4XX_GPIO_IN);
irq = gpio_to_irq(gpio);
if (NO_IRQ == irq)
return NO_IRQ;
if (irq_set_irq_type(irq, IRQF_TRIGGER_FALLING)) {
pr_err("cannot set trigger type for irq %d\n", irq);
return NO_IRQ;
}
if (request_irq(irq, isr, 0, DRIVER, &ixp_clock)) {
pr_err("request_irq failed for irq %d\n", irq);
return NO_IRQ;
}
return irq;
}
static void __exit ptp_ixp_exit(void)
{
free_irq(MASTER_IRQ, &ixp_clock);
free_irq(SLAVE_IRQ, &ixp_clock);
ixp46x_phc_index = -1;
ptp_clock_unregister(ixp_clock.ptp_clock);
}
static int __init ptp_ixp_init(void)
{
if (!cpu_is_ixp46x())
return -ENODEV;
ixp_clock.regs =
(struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
ixp_clock.caps = ptp_ixp_caps;
ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
if (IS_ERR(ixp_clock.ptp_clock))
return PTR_ERR(ixp_clock.ptp_clock);
ixp46x_phc_index = ptp_clock_index(ixp_clock.ptp_clock);
__raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
__raw_writel(1, &ixp_clock.regs->trgt_lo);
__raw_writel(0, &ixp_clock.regs->trgt_hi);
__raw_writel(TTIPEND, &ixp_clock.regs->event);
if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
goto no_master;
}
if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
goto no_slave;
}
return 0;
no_slave:
free_irq(MASTER_IRQ, &ixp_clock);
no_master:
ptp_clock_unregister(ixp_clock.ptp_clock);
return -ENODEV;
}
module_init(ptp_ixp_init);
module_exit(ptp_ixp_exit);
MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
MODULE_LICENSE("GPL");