// SPDX-License-Identifier: GPL-2.0
/*
* Fast Ethernet Controller (ENET) PTP driver for MX6x.
*
* Copyright (C) 2012 Freescale Semiconductor, Inc.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/phy.h>
#include <linux/fec.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/of_net.h>
#include "fec.h"
/* FEC 1588 register bits */
#define FEC_T_CTRL_SLAVE 0x00002000
#define FEC_T_CTRL_CAPTURE 0x00000800
#define FEC_T_CTRL_RESTART 0x00000200
#define FEC_T_CTRL_PERIOD_RST 0x00000030
#define FEC_T_CTRL_PERIOD_EN 0x00000010
#define FEC_T_CTRL_ENABLE 0x00000001
#define FEC_T_INC_MASK 0x0000007f
#define FEC_T_INC_OFFSET 0
#define FEC_T_INC_CORR_MASK 0x00007f00
#define FEC_T_INC_CORR_OFFSET 8
#define FEC_T_CTRL_PINPER 0x00000080
#define FEC_T_TF0_MASK 0x00000001
#define FEC_T_TF0_OFFSET 0
#define FEC_T_TF1_MASK 0x00000002
#define FEC_T_TF1_OFFSET 1
#define FEC_T_TF2_MASK 0x00000004
#define FEC_T_TF2_OFFSET 2
#define FEC_T_TF3_MASK 0x00000008
#define FEC_T_TF3_OFFSET 3
#define FEC_T_TDRE_MASK 0x00000001
#define FEC_T_TDRE_OFFSET 0
#define FEC_T_TMODE_MASK 0x0000003C
#define FEC_T_TMODE_OFFSET 2
#define FEC_T_TIE_MASK 0x00000040
#define FEC_T_TIE_OFFSET 6
#define FEC_T_TF_MASK 0x00000080
#define FEC_T_TF_OFFSET 7
#define FEC_ATIME_CTRL 0x400
#define FEC_ATIME 0x404
#define FEC_ATIME_EVT_OFFSET 0x408
#define FEC_ATIME_EVT_PERIOD 0x40c
#define FEC_ATIME_CORR 0x410
#define FEC_ATIME_INC 0x414
#define FEC_TS_TIMESTAMP 0x418
#define FEC_TGSR 0x604
#define FEC_TCSR(n) (0x608 + n * 0x08)
#define FEC_TCCR(n) (0x60C + n * 0x08)
#define MAX_TIMER_CHANNEL 3
#define FEC_TMODE_TOGGLE 0x05
#define FEC_HIGH_PULSE 0x0F
#define FEC_CC_MULT (1 << 31)
#define FEC_COUNTER_PERIOD (1 << 31)
#define PPS_OUPUT_RELOAD_PERIOD NSEC_PER_SEC
#define FEC_CHANNLE_0 0
#define DEFAULT_PPS_CHANNEL FEC_CHANNLE_0
/**
* fec_ptp_enable_pps
* @fep: the fec_enet_private structure handle
* @enable: enable the channel pps output
*
* This function enble the PPS ouput on the timer channel.
*/
static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable)
{
unsigned long flags;
u32 val, tempval;
struct timespec64 ts;
u64 ns;
val = 0;
if (!(fep->hwts_tx_en || fep->hwts_rx_en)) {
dev_err(&fep->pdev->dev, "No ptp stack is running\n");
return -EINVAL;
}
if (fep->pps_enable == enable)
return 0;
fep->pps_channel = DEFAULT_PPS_CHANNEL;
fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
spin_lock_irqsave(&fep->tmreg_lock, flags);
if (enable) {
/* clear capture or output compare interrupt status if have.
*/
writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
/* It is recommended to double check the TMODE field in the
* TCSR register to be cleared before the first compare counter
* is written into TCCR register. Just add a double check.
*/
val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
do {
val &= ~(FEC_T_TMODE_MASK);
writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
} while (val & FEC_T_TMODE_MASK);
/* Dummy read counter to update the counter */
timecounter_read(&fep->tc);
/* We want to find the first compare event in the next
* second point. So we need to know what the ptp time
* is now and how many nanoseconds is ahead to get next second.
* The remaining nanosecond ahead before the next second would be
* NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
* to current timer would be next second.
*/
tempval = readl(fep->hwp + FEC_ATIME_CTRL);
tempval |= FEC_T_CTRL_CAPTURE;
writel(tempval, fep->hwp + FEC_ATIME_CTRL);
tempval = readl(fep->hwp + FEC_ATIME);
/* Convert the ptp local counter to 1588 timestamp */
ns = timecounter_cyc2time(&fep->tc, tempval);
ts = ns_to_timespec64(ns);
/* The tempval is less than 3 seconds, and so val is less than
* 4 seconds. No overflow for 32bit calculation.
*/
val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
/* Need to consider the situation that the current time is
* very close to the second point, which means NSEC_PER_SEC
* - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
* is still running when we calculate the first compare event, it is
* possible that the remaining nanoseonds run out before the compare
* counter is calculated and written into TCCR register. To avoid
* this possibility, we will set the compare event to be the next
* of next second. The current setting is 31-bit timer and wrap
* around over 2 seconds. So it is okay to set the next of next
* seond for the timer.
*/
val += NSEC_PER_SEC;
/* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
* ptp counter, which maybe cause 32-bit wrap. Since the
* (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
* We can ensure the wrap will not cause issue. If the offset
* is bigger than fep->cc.mask would be a error.
*/
val &= fep->cc.mask;
writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
/* Calculate the second the compare event timestamp */
fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
/* * Enable compare event when overflow */
val = readl(fep->hwp + FEC_ATIME_CTRL);
val |= FEC_T_CTRL_PINPER;
writel(val, fep->hwp + FEC_ATIME_CTRL);
/* Compare channel setting. */
val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
val &= ~(1 << FEC_T_TDRE_OFFSET);
val &= ~(FEC_T_TMODE_MASK);
val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
/* Write the second compare event timestamp and calculate
* the third timestamp. Refer the TCCR register detail in the spec.
*/
writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
} else {
writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
}
fep->pps_enable = enable;
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
return 0;
}
/**
* fec_ptp_read - read raw cycle counter (to be used by time counter)
* @cc: the cyclecounter structure
*
* this function reads the cyclecounter registers and is called by the
* cyclecounter structure used to construct a ns counter from the
* arbitrary fixed point registers
*/
static u64 fec_ptp_read(const struct cyclecounter *cc)
{
struct fec_enet_private *fep =
container_of(cc, struct fec_enet_private, cc);
const struct platform_device_id *id_entry =
platform_get_device_id(fep->pdev);
u32 tempval;
tempval = readl(fep->hwp + FEC_ATIME_CTRL);
tempval |= FEC_T_CTRL_CAPTURE;
writel(tempval, fep->hwp + FEC_ATIME_CTRL);
if (id_entry->driver_data & FEC_QUIRK_BUG_CAPTURE)
udelay(1);
return readl(fep->hwp + FEC_ATIME);
}
/**
* fec_ptp_start_cyclecounter - create the cycle counter from hw
* @ndev: network device
*
* this function initializes the timecounter and cyclecounter
* structures for use in generated a ns counter from the arbitrary
* fixed point cycles registers in the hardware.
*/
void fec_ptp_start_cyclecounter(struct net_device *ndev)
{
struct fec_enet_private *fep = netdev_priv(ndev);
unsigned long flags;
int inc;
inc = 1000000000 / fep->cycle_speed;
/* grab the ptp lock */
spin_lock_irqsave(&fep->tmreg_lock, flags);
/* 1ns counter */
writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
/* use 31-bit timer counter */
writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
fep->hwp + FEC_ATIME_CTRL);
memset(&fep->cc, 0, sizeof(fep->cc));
fep->cc.read = fec_ptp_read;
fep->cc.mask = CLOCKSOURCE_MASK(31);
fep->cc.shift = 31;
fep->cc.mult = FEC_CC_MULT;
/* reset the ns time counter */
timecounter_init(&fep->tc, &fep->cc, ktime_to_ns(ktime_get_real()));
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
}
/**
* fec_ptp_adjfreq - adjust ptp cycle frequency
* @ptp: the ptp clock structure
* @ppb: parts per billion adjustment from base
*
* Adjust the frequency of the ptp cycle counter by the
* indicated ppb from the base frequency.
*
* Because ENET hardware frequency adjust is complex,
* using software method to do that.
*/
static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
unsigned long flags;
int neg_adj = 0;
u32 i, tmp;
u32 corr_inc, corr_period;
u32 corr_ns;
u64 lhs, rhs;
struct fec_enet_private *fep =
container_of(ptp, struct fec_enet_private, ptp_caps);
if (ppb == 0)
return 0;
if (ppb < 0) {
ppb = -ppb;
neg_adj = 1;
}
/* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
* Try to find the corr_inc between 1 to fep->ptp_inc to
* meet adjustment requirement.
*/
lhs = NSEC_PER_SEC;
rhs = (u64)ppb * (u64)fep->ptp_inc;
for (i = 1; i <= fep->ptp_inc; i++) {
if (lhs >= rhs) {
corr_inc = i;
corr_period = div_u64(lhs, rhs);
break;
}
lhs += NSEC_PER_SEC;
}
/* Not found? Set it to high value - double speed
* correct in every clock step.
*/
if (i > fep->ptp_inc) {
corr_inc = fep->ptp_inc;
corr_period = 1;
}
if (neg_adj)
corr_ns = fep->ptp_inc - corr_inc;
else
corr_ns = fep->ptp_inc + corr_inc;
spin_lock_irqsave(&fep->tmreg_lock, flags);
tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
writel(tmp, fep->hwp + FEC_ATIME_INC);
corr_period = corr_period > 1 ? corr_period - 1 : corr_period;
writel(corr_period, fep->hwp + FEC_ATIME_CORR);
/* dummy read to update the timer. */
timecounter_read(&fep->tc);
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
return 0;
}
/**
* fec_ptp_adjtime
* @ptp: the ptp clock structure
* @delta: offset to adjust the cycle counter by
*
* adjust the timer by resetting the timecounter structure.
*/
static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
struct fec_enet_private *fep =
container_of(ptp, struct fec_enet_private, ptp_caps);
unsigned long flags;
spin_lock_irqsave(&fep->tmreg_lock, flags);
timecounter_adjtime(&fep->tc, delta);
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
return 0;
}
/**
* fec_ptp_gettime
* @ptp: the ptp clock structure
* @ts: timespec structure to hold the current time value
*
* read the timecounter and return the correct value on ns,
* after converting it into a struct timespec.
*/
static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
{
struct fec_enet_private *adapter =
container_of(ptp, struct fec_enet_private, ptp_caps);
u64 ns;
unsigned long flags;
spin_lock_irqsave(&adapter->tmreg_lock, flags);
ns = timecounter_read(&adapter->tc);
spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
*ts = ns_to_timespec64(ns);
return 0;
}
/**
* fec_ptp_settime
* @ptp: the ptp clock structure
* @ts: the timespec containing the new time for the cycle counter
*
* reset the timecounter to use a new base value instead of the kernel
* wall timer value.
*/
static int fec_ptp_settime(struct ptp_clock_info *ptp,
const struct timespec64 *ts)
{
struct fec_enet_private *fep =
container_of(ptp, struct fec_enet_private, ptp_caps);
u64 ns;
unsigned long flags;
u32 counter;
mutex_lock(&fep->ptp_clk_mutex);
/* Check the ptp clock */
if (!fep->ptp_clk_on) {
mutex_unlock(&fep->ptp_clk_mutex);
return -EINVAL;
}
ns = timespec64_to_ns(ts);
/* Get the timer value based on timestamp.
* Update the counter with the masked value.
*/
counter = ns & fep->cc.mask;
spin_lock_irqsave(&fep->tmreg_lock, flags);
writel(counter, fep->hwp + FEC_ATIME);
timecounter_init(&fep->tc, &fep->cc, ns);
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
mutex_unlock(&fep->ptp_clk_mutex);
return 0;
}
/**
* fec_ptp_enable
* @ptp: the ptp clock structure
* @rq: the requested feature to change
* @on: whether to enable or disable the feature
*
*/
static int fec_ptp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
struct fec_enet_private *fep =
container_of(ptp, struct fec_enet_private, ptp_caps);
int ret = 0;
if (rq->type == PTP_CLK_REQ_PPS) {
ret = fec_ptp_enable_pps(fep, on);
return ret;
}
return -EOPNOTSUPP;
}
int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr)
{
struct fec_enet_private *fep = netdev_priv(ndev);
struct hwtstamp_config config;
if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
return -EFAULT;
/* reserved for future extensions */
if (config.flags)
return -EINVAL;
switch (config.tx_type) {
case HWTSTAMP_TX_OFF:
fep->hwts_tx_en = 0;
break;
case HWTSTAMP_TX_ON:
fep->hwts_tx_en = 1;
break;
default:
return -ERANGE;
}
switch (config.rx_filter) {
case HWTSTAMP_FILTER_NONE:
if (fep->hwts_rx_en)
fep->hwts_rx_en = 0;
config.rx_filter = HWTSTAMP_FILTER_NONE;
break;
default:
fep->hwts_rx_en = 1;
config.rx_filter = HWTSTAMP_FILTER_ALL;
break;
}
return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
-EFAULT : 0;
}
int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr)
{
struct fec_enet_private *fep = netdev_priv(ndev);
struct hwtstamp_config config;
config.flags = 0;
config.tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
config.rx_filter = (fep->hwts_rx_en ?
HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
-EFAULT : 0;
}
/**
* fec_time_keep - call timecounter_read every second to avoid timer overrun
* because ENET just support 32bit counter, will timeout in 4s
*/
static void fec_time_keep(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep);
u64 ns;
unsigned long flags;
mutex_lock(&fep->ptp_clk_mutex);
if (fep->ptp_clk_on) {
spin_lock_irqsave(&fep->tmreg_lock, flags);
ns = timecounter_read(&fep->tc);
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
}
mutex_unlock(&fep->ptp_clk_mutex);
schedule_delayed_work(&fep->time_keep, HZ);
}
/* This function checks the pps event and reloads the timer compare counter. */
static irqreturn_t fec_pps_interrupt(int irq, void *dev_id)
{
struct net_device *ndev = dev_id;
struct fec_enet_private *fep = netdev_priv(ndev);
u32 val;
u8 channel = fep->pps_channel;
struct ptp_clock_event event;
val = readl(fep->hwp + FEC_TCSR(channel));
if (val & FEC_T_TF_MASK) {
/* Write the next next compare(not the next according the spec)
* value to the register
*/
writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
do {
writel(val, fep->hwp + FEC_TCSR(channel));
} while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
/* Update the counter; */
fep->next_counter = (fep->next_counter + fep->reload_period) &
fep->cc.mask;
event.type = PTP_CLOCK_PPS;
ptp_clock_event(fep->ptp_clock, &event);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/**
* fec_ptp_init
* @ndev: The FEC network adapter
*
* This function performs the required steps for enabling ptp
* support. If ptp support has already been loaded it simply calls the
* cyclecounter init routine and exits.
*/
void fec_ptp_init(struct platform_device *pdev, int irq_idx)
{
struct net_device *ndev = platform_get_drvdata(pdev);
struct fec_enet_private *fep = netdev_priv(ndev);
int irq;
int ret;
fep->ptp_caps.owner = THIS_MODULE;
snprintf(fep->ptp_caps.name, 16, "fec ptp");
fep->ptp_caps.max_adj = 250000000;
fep->ptp_caps.n_alarm = 0;
fep->ptp_caps.n_ext_ts = 0;
fep->ptp_caps.n_per_out = 0;
fep->ptp_caps.n_pins = 0;
fep->ptp_caps.pps = 1;
fep->ptp_caps.adjfreq = fec_ptp_adjfreq;
fep->ptp_caps.adjtime = fec_ptp_adjtime;
fep->ptp_caps.gettime64 = fec_ptp_gettime;
fep->ptp_caps.settime64 = fec_ptp_settime;
fep->ptp_caps.enable = fec_ptp_enable;
fep->cycle_speed = clk_get_rate(fep->clk_ptp);
fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
spin_lock_init(&fep->tmreg_lock);
fec_ptp_start_cyclecounter(ndev);
INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
irq = platform_get_irq_byname(pdev, "pps");
if (irq < 0)
irq = platform_get_irq(pdev, irq_idx);
/* Failure to get an irq is not fatal,
* only the PTP_CLOCK_PPS clock events should stop
*/
if (irq >= 0) {
ret = devm_request_irq(&pdev->dev, irq, fec_pps_interrupt,
0, pdev->name, ndev);
if (ret < 0)
dev_warn(&pdev->dev, "request for pps irq failed(%d)\n",
ret);
}
fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev);
if (IS_ERR(fep->ptp_clock)) {
fep->ptp_clock = NULL;
dev_err(&pdev->dev, "ptp_clock_register failed\n");
}
schedule_delayed_work(&fep->time_keep, HZ);
}
void fec_ptp_stop(struct platform_device *pdev)
{
struct net_device *ndev = platform_get_drvdata(pdev);
struct fec_enet_private *fep = netdev_priv(ndev);
cancel_delayed_work_sync(&fep->time_keep);
if (fep->ptp_clock)
ptp_clock_unregister(fep->ptp_clock);
}
