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linux/drivers/net/gianfar_ptp.c
Richard Cochran cbc056602c gianfar: fix fiper alignment after resetting the time 
After resetting the time, the PPS signals on the FIPER output channels
are incorrectly offset from the clock time, as can be readily verified
by a looping back the FIPER to the external time stamp input.

Despite its name, setting the "Fiper Realignment Disable" bit seems to
fix the problem, at least on the P2020.

Also, following the example code from the Freescale BSP, it is not really
necessary to disable and re-enable the timer in order to reprogram the
FIPER. (The documentation is rather unclear on this point. It seems that
writing to the alarm register also disables the FIPER.)

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Cc: <stable@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-07 22:53:22 -07:00

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/*
* PTP 1588 clock using the eTSEC
*
* 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/hrtimer.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/timex.h>
#include <linux/io.h>
#include <linux/ptp_clock_kernel.h>
#include "gianfar.h"
/*
* gianfar ptp registers
* Generated by regen.tcl on Thu May 13 01:38:57 PM CEST 2010
*/
struct gianfar_ptp_registers {
u32 tmr_ctrl; /* Timer control register */
u32 tmr_tevent; /* Timestamp event register */
u32 tmr_temask; /* Timer event mask register */
u32 tmr_pevent; /* Timestamp event register */
u32 tmr_pemask; /* Timer event mask register */
u32 tmr_stat; /* Timestamp status register */
u32 tmr_cnt_h; /* Timer counter high register */
u32 tmr_cnt_l; /* Timer counter low register */
u32 tmr_add; /* Timer drift compensation addend register */
u32 tmr_acc; /* Timer accumulator register */
u32 tmr_prsc; /* Timer prescale */
u8 res1[4];
u32 tmroff_h; /* Timer offset high */
u32 tmroff_l; /* Timer offset low */
u8 res2[8];
u32 tmr_alarm1_h; /* Timer alarm 1 high register */
u32 tmr_alarm1_l; /* Timer alarm 1 high register */
u32 tmr_alarm2_h; /* Timer alarm 2 high register */
u32 tmr_alarm2_l; /* Timer alarm 2 high register */
u8 res3[48];
u32 tmr_fiper1; /* Timer fixed period interval */
u32 tmr_fiper2; /* Timer fixed period interval */
u32 tmr_fiper3; /* Timer fixed period interval */
u8 res4[20];
u32 tmr_etts1_h; /* Timestamp of general purpose external trigger */
u32 tmr_etts1_l; /* Timestamp of general purpose external trigger */
u32 tmr_etts2_h; /* Timestamp of general purpose external trigger */
u32 tmr_etts2_l; /* Timestamp of general purpose external trigger */
};
/* Bit definitions for the TMR_CTRL register */
#define ALM1P (1<<31) /* Alarm1 output polarity */
#define ALM2P (1<<30) /* Alarm2 output polarity */
#define FS (1<<28) /* FIPER start indication */
#define PP1L (1<<27) /* Fiper1 pulse loopback mode enabled. */
#define PP2L (1<<26) /* Fiper2 pulse loopback mode enabled. */
#define TCLK_PERIOD_SHIFT (16) /* 1588 timer reference clock period. */
#define TCLK_PERIOD_MASK (0x3ff)
#define RTPE (1<<15) /* Record Tx Timestamp to PAL Enable. */
#define FRD (1<<14) /* FIPER Realignment Disable */
#define ESFDP (1<<11) /* External Tx/Rx SFD Polarity. */
#define ESFDE (1<<10) /* External Tx/Rx SFD Enable. */
#define ETEP2 (1<<9) /* External trigger 2 edge polarity */
#define ETEP1 (1<<8) /* External trigger 1 edge polarity */
#define COPH (1<<7) /* Generated clock output phase. */
#define CIPH (1<<6) /* External oscillator input clock phase */
#define TMSR (1<<5) /* Timer soft reset. */
#define BYP (1<<3) /* Bypass drift compensated clock */
#define TE (1<<2) /* 1588 timer enable. */
#define CKSEL_SHIFT (0) /* 1588 Timer reference clock source */
#define CKSEL_MASK (0x3)
/* Bit definitions for the TMR_TEVENT register */
#define ETS2 (1<<25) /* External trigger 2 timestamp sampled */
#define ETS1 (1<<24) /* External trigger 1 timestamp sampled */
#define ALM2 (1<<17) /* Current time = alarm time register 2 */
#define ALM1 (1<<16) /* Current time = alarm time register 1 */
#define PP1 (1<<7) /* periodic pulse generated on FIPER1 */
#define PP2 (1<<6) /* periodic pulse generated on FIPER2 */
#define PP3 (1<<5) /* periodic pulse generated on FIPER3 */
/* Bit definitions for the TMR_TEMASK register */
#define ETS2EN (1<<25) /* External trigger 2 timestamp enable */
#define ETS1EN (1<<24) /* External trigger 1 timestamp enable */
#define ALM2EN (1<<17) /* Timer ALM2 event enable */
#define ALM1EN (1<<16) /* Timer ALM1 event enable */
#define PP1EN (1<<7) /* Periodic pulse event 1 enable */
#define PP2EN (1<<6) /* Periodic pulse event 2 enable */
/* Bit definitions for the TMR_PEVENT register */
#define TXP2 (1<<9) /* PTP transmitted timestamp im TXTS2 */
#define TXP1 (1<<8) /* PTP transmitted timestamp in TXTS1 */
#define RXP (1<<0) /* PTP frame has been received */
/* Bit definitions for the TMR_PEMASK register */
#define TXP2EN (1<<9) /* Transmit PTP packet event 2 enable */
#define TXP1EN (1<<8) /* Transmit PTP packet event 1 enable */
#define RXPEN (1<<0) /* Receive PTP packet event enable */
/* Bit definitions for the TMR_STAT register */
#define STAT_VEC_SHIFT (0) /* Timer general purpose status vector */
#define STAT_VEC_MASK (0x3f)
/* Bit definitions for the TMR_PRSC register */
#define PRSC_OCK_SHIFT (0) /* Output clock division/prescale factor. */
#define PRSC_OCK_MASK (0xffff)
#define DRIVER "gianfar_ptp"
#define DEFAULT_CKSEL 1
#define N_ALARM 1 /* first alarm is used internally to reset fipers */
#define N_EXT_TS 2
#define REG_SIZE sizeof(struct gianfar_ptp_registers)
struct etsects {
struct gianfar_ptp_registers *regs;
spinlock_t lock; /* protects regs */
struct ptp_clock *clock;
struct ptp_clock_info caps;
struct resource *rsrc;
int irq;
u64 alarm_interval; /* for periodic alarm */
u64 alarm_value;
u32 tclk_period; /* nanoseconds */
u32 tmr_prsc;
u32 tmr_add;
u32 cksel;
u32 tmr_fiper1;
u32 tmr_fiper2;
};
/*
* Register access functions
*/
/* Caller must hold etsects->lock. */
static u64 tmr_cnt_read(struct etsects *etsects)
{
u64 ns;
u32 lo, hi;
lo = gfar_read(&etsects->regs->tmr_cnt_l);
hi = gfar_read(&etsects->regs->tmr_cnt_h);
ns = ((u64) hi) << 32;
ns |= lo;
return ns;
}
/* Caller must hold etsects->lock. */
static void tmr_cnt_write(struct etsects *etsects, u64 ns)
{
u32 hi = ns >> 32;
u32 lo = ns & 0xffffffff;
gfar_write(&etsects->regs->tmr_cnt_l, lo);
gfar_write(&etsects->regs->tmr_cnt_h, hi);
}
/* Caller must hold etsects->lock. */
static void set_alarm(struct etsects *etsects)
{
u64 ns;
u32 lo, hi;
ns = tmr_cnt_read(etsects) + 1500000000ULL;
ns = div_u64(ns, 1000000000UL) * 1000000000ULL;
ns -= etsects->tclk_period;
hi = ns >> 32;
lo = ns & 0xffffffff;
gfar_write(&etsects->regs->tmr_alarm1_l, lo);
gfar_write(&etsects->regs->tmr_alarm1_h, hi);
}
/* Caller must hold etsects->lock. */
static void set_fipers(struct etsects *etsects)
{
set_alarm(etsects);
gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1);
gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2);
}
/*
* Interrupt service routine
*/
static irqreturn_t isr(int irq, void *priv)
{
struct etsects *etsects = priv;
struct ptp_clock_event event;
u64 ns;
u32 ack = 0, lo, hi, mask, val;
val = gfar_read(&etsects->regs->tmr_tevent);
if (val & ETS1) {
ack |= ETS1;
hi = gfar_read(&etsects->regs->tmr_etts1_h);
lo = gfar_read(&etsects->regs->tmr_etts1_l);
event.type = PTP_CLOCK_EXTTS;
event.index = 0;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
ptp_clock_event(etsects->clock, &event);
}
if (val & ETS2) {
ack |= ETS2;
hi = gfar_read(&etsects->regs->tmr_etts2_h);
lo = gfar_read(&etsects->regs->tmr_etts2_l);
event.type = PTP_CLOCK_EXTTS;
event.index = 1;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
ptp_clock_event(etsects->clock, &event);
}
if (val & ALM2) {
ack |= ALM2;
if (etsects->alarm_value) {
event.type = PTP_CLOCK_ALARM;
event.index = 0;
event.timestamp = etsects->alarm_value;
ptp_clock_event(etsects->clock, &event);
}
if (etsects->alarm_interval) {
ns = etsects->alarm_value + etsects->alarm_interval;
hi = ns >> 32;
lo = ns & 0xffffffff;
spin_lock(&etsects->lock);
gfar_write(&etsects->regs->tmr_alarm2_l, lo);
gfar_write(&etsects->regs->tmr_alarm2_h, hi);
spin_unlock(&etsects->lock);
etsects->alarm_value = ns;
} else {
gfar_write(&etsects->regs->tmr_tevent, ALM2);
spin_lock(&etsects->lock);
mask = gfar_read(&etsects->regs->tmr_temask);
mask &= ~ALM2EN;
gfar_write(&etsects->regs->tmr_temask, mask);
spin_unlock(&etsects->lock);
etsects->alarm_value = 0;
etsects->alarm_interval = 0;
}
}
if (val & PP1) {
ack |= PP1;
event.type = PTP_CLOCK_PPS;
ptp_clock_event(etsects->clock, &event);
}
if (ack) {
gfar_write(&etsects->regs->tmr_tevent, ack);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
/*
* PTP clock operations
*/
static int ptp_gianfar_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
u64 adj;
u32 diff, tmr_add;
int neg_adj = 0;
struct etsects *etsects = container_of(ptp, struct etsects, caps);
if (ppb < 0) {
neg_adj = 1;
ppb = -ppb;
}
tmr_add = etsects->tmr_add;
adj = tmr_add;
adj *= ppb;
diff = div_u64(adj, 1000000000ULL);
tmr_add = neg_adj ? tmr_add - diff : tmr_add + diff;
gfar_write(&etsects->regs->tmr_add, tmr_add);
return 0;
}
static int ptp_gianfar_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
s64 now;
unsigned long flags;
struct etsects *etsects = container_of(ptp, struct etsects, caps);
spin_lock_irqsave(&etsects->lock, flags);
now = tmr_cnt_read(etsects);
now += delta;
tmr_cnt_write(etsects, now);
spin_unlock_irqrestore(&etsects->lock, flags);
set_fipers(etsects);
return 0;
}
static int ptp_gianfar_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
{
u64 ns;
u32 remainder;
unsigned long flags;
struct etsects *etsects = container_of(ptp, struct etsects, caps);
spin_lock_irqsave(&etsects->lock, flags);
ns = tmr_cnt_read(etsects);
spin_unlock_irqrestore(&etsects->lock, flags);
ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
ts->tv_nsec = remainder;
return 0;
}
static int ptp_gianfar_settime(struct ptp_clock_info *ptp,
const struct timespec *ts)
{
u64 ns;
unsigned long flags;
struct etsects *etsects = container_of(ptp, struct etsects, caps);
ns = ts->tv_sec * 1000000000ULL;
ns += ts->tv_nsec;
spin_lock_irqsave(&etsects->lock, flags);
tmr_cnt_write(etsects, ns);
set_fipers(etsects);
spin_unlock_irqrestore(&etsects->lock, flags);
return 0;
}
static int ptp_gianfar_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
struct etsects *etsects = container_of(ptp, struct etsects, caps);
unsigned long flags;
u32 bit, mask;
switch (rq->type) {
case PTP_CLK_REQ_EXTTS:
switch (rq->extts.index) {
case 0:
bit = ETS1EN;
break;
case 1:
bit = ETS2EN;
break;
default:
return -EINVAL;
}
spin_lock_irqsave(&etsects->lock, flags);
mask = gfar_read(&etsects->regs->tmr_temask);
if (on)
mask |= bit;
else
mask &= ~bit;
gfar_write(&etsects->regs->tmr_temask, mask);
spin_unlock_irqrestore(&etsects->lock, flags);
return 0;
case PTP_CLK_REQ_PPS:
spin_lock_irqsave(&etsects->lock, flags);
mask = gfar_read(&etsects->regs->tmr_temask);
if (on)
mask |= PP1EN;
else
mask &= ~PP1EN;
gfar_write(&etsects->regs->tmr_temask, mask);
spin_unlock_irqrestore(&etsects->lock, flags);
return 0;
default:
break;
}
return -EOPNOTSUPP;
}
static struct ptp_clock_info ptp_gianfar_caps = {
.owner = THIS_MODULE,
.name = "gianfar clock",
.max_adj = 512000,
.n_alarm = N_ALARM,
.n_ext_ts = N_EXT_TS,
.n_per_out = 0,
.pps = 1,
.adjfreq = ptp_gianfar_adjfreq,
.adjtime = ptp_gianfar_adjtime,
.gettime = ptp_gianfar_gettime,
.settime = ptp_gianfar_settime,
.enable = ptp_gianfar_enable,
};
/* OF device tree */
static int get_of_u32(struct device_node *node, char *str, u32 *val)
{
int plen;
const u32 *prop = of_get_property(node, str, &plen);
if (!prop || plen != sizeof(*prop))
return -1;
*val = *prop;
return 0;
}
static int gianfar_ptp_probe(struct platform_device *dev)
{
struct device_node *node = dev->dev.of_node;
struct etsects *etsects;
struct timespec now;
int err = -ENOMEM;
u32 tmr_ctrl;
unsigned long flags;
etsects = kzalloc(sizeof(*etsects), GFP_KERNEL);
if (!etsects)
goto no_memory;
err = -ENODEV;
etsects->caps = ptp_gianfar_caps;
etsects->cksel = DEFAULT_CKSEL;
if (get_of_u32(node, "fsl,tclk-period", &etsects->tclk_period) ||
get_of_u32(node, "fsl,tmr-prsc", &etsects->tmr_prsc) ||
get_of_u32(node, "fsl,tmr-add", &etsects->tmr_add) ||
get_of_u32(node, "fsl,tmr-fiper1", &etsects->tmr_fiper1) ||
get_of_u32(node, "fsl,tmr-fiper2", &etsects->tmr_fiper2) ||
get_of_u32(node, "fsl,max-adj", &etsects->caps.max_adj)) {
pr_err("device tree node missing required elements\n");
goto no_node;
}
etsects->irq = platform_get_irq(dev, 0);
if (etsects->irq == NO_IRQ) {
pr_err("irq not in device tree\n");
goto no_node;
}
if (request_irq(etsects->irq, isr, 0, DRIVER, etsects)) {
pr_err("request_irq failed\n");
goto no_node;
}
etsects->rsrc = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!etsects->rsrc) {
pr_err("no resource\n");
goto no_resource;
}
if (request_resource(&ioport_resource, etsects->rsrc)) {
pr_err("resource busy\n");
goto no_resource;
}
spin_lock_init(&etsects->lock);
etsects->regs = ioremap(etsects->rsrc->start,
resource_size(etsects->rsrc));
if (!etsects->regs) {
pr_err("ioremap ptp registers failed\n");
goto no_ioremap;
}
getnstimeofday(&now);
ptp_gianfar_settime(&etsects->caps, &now);
tmr_ctrl =
(etsects->tclk_period & TCLK_PERIOD_MASK) << TCLK_PERIOD_SHIFT |
(etsects->cksel & CKSEL_MASK) << CKSEL_SHIFT;
spin_lock_irqsave(&etsects->lock, flags);
gfar_write(&etsects->regs->tmr_ctrl, tmr_ctrl);
gfar_write(&etsects->regs->tmr_add, etsects->tmr_add);
gfar_write(&etsects->regs->tmr_prsc, etsects->tmr_prsc);
gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1);
gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2);
set_alarm(etsects);
gfar_write(&etsects->regs->tmr_ctrl, tmr_ctrl|FS|RTPE|TE|FRD);
spin_unlock_irqrestore(&etsects->lock, flags);
etsects->clock = ptp_clock_register(&etsects->caps);
if (IS_ERR(etsects->clock)) {
err = PTR_ERR(etsects->clock);
goto no_clock;
}
dev_set_drvdata(&dev->dev, etsects);
return 0;
no_clock:
no_ioremap:
release_resource(etsects->rsrc);
no_resource:
free_irq(etsects->irq, etsects);
no_node:
kfree(etsects);
no_memory:
return err;
}
static int gianfar_ptp_remove(struct platform_device *dev)
{
struct etsects *etsects = dev_get_drvdata(&dev->dev);
gfar_write(&etsects->regs->tmr_temask, 0);
gfar_write(&etsects->regs->tmr_ctrl, 0);
ptp_clock_unregister(etsects->clock);
iounmap(etsects->regs);
release_resource(etsects->rsrc);
free_irq(etsects->irq, etsects);
kfree(etsects);
return 0;
}
static struct of_device_id match_table[] = {
{ .compatible = "fsl,etsec-ptp" },
{},
};
static struct platform_driver gianfar_ptp_driver = {
.driver = {
.name = "gianfar_ptp",
.of_match_table = match_table,
.owner = THIS_MODULE,
},
.probe = gianfar_ptp_probe,
.remove = gianfar_ptp_remove,
};
/* module operations */
static int __init ptp_gianfar_init(void)
{
return platform_driver_register(&gianfar_ptp_driver);
}
module_init(ptp_gianfar_init);
static void __exit ptp_gianfar_exit(void)
{
platform_driver_unregister(&gianfar_ptp_driver);
}
module_exit(ptp_gianfar_exit);
MODULE_AUTHOR("Richard Cochran <richard.cochran@omicron.at>");
MODULE_DESCRIPTION("PTP clock using the eTSEC");
MODULE_LICENSE("GPL");
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