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// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* DSA driver for:
* Hirschmann Hellcreek TSN switch.
*
* Copyright (C) 2019,2020 Hochschule Offenburg
* Copyright (C) 2019,2020 Linutronix GmbH
* Authors: Kamil Alkhouri <kamil.alkhouri@hs-offenburg.de>
* Kurt Kanzenbach <kurt@linutronix.de>
*/
#include <linux/of.h>
#include <linux/ptp_clock_kernel.h>
#include "hellcreek.h"
#include "hellcreek_ptp.h"
#include "hellcreek_hwtstamp.h"
u16 hellcreek_ptp_read(struct hellcreek *hellcreek, unsigned int offset)
{
return readw(hellcreek->ptp_base + offset);
}
void hellcreek_ptp_write(struct hellcreek *hellcreek, u16 data,
unsigned int offset)
{
writew(data, hellcreek->ptp_base + offset);
}
/* Get nanoseconds from PTP clock */
static u64 hellcreek_ptp_clock_read(struct hellcreek *hellcreek)
{
u16 nsl, nsh;
/* Take a snapshot */
hellcreek_ptp_write(hellcreek, PR_COMMAND_C_SS, PR_COMMAND_C);
/* The time of the day is saved as 96 bits. However, due to hardware
* limitations the seconds are not or only partly kept in the PTP
* core. Currently only three bits for the seconds are available. That's
* why only the nanoseconds are used and the seconds are tracked in
* software. Anyway due to internal locking all five registers should be
* read.
*/
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsl = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
return (u64)nsl | ((u64)nsh << 16);
}
static u64 __hellcreek_ptp_gettime(struct hellcreek *hellcreek)
{
u64 ns;
ns = hellcreek_ptp_clock_read(hellcreek);
if (ns < hellcreek->last_ts)
hellcreek->seconds++;
hellcreek->last_ts = ns;
ns += hellcreek->seconds * NSEC_PER_SEC;
return ns;
}
/* Retrieve the seconds parts in nanoseconds for a packet timestamped with @ns.
* There has to be a check whether an overflow occurred between the packet
* arrival and now. If so use the correct seconds (-1) for calculating the
* packet arrival time.
*/
u64 hellcreek_ptp_gettime_seconds(struct hellcreek *hellcreek, u64 ns)
{
u64 s;
__hellcreek_ptp_gettime(hellcreek);
if (hellcreek->last_ts > ns)
s = hellcreek->seconds * NSEC_PER_SEC;
else
s = (hellcreek->seconds - 1) * NSEC_PER_SEC;
return s;
}
static int hellcreek_ptp_gettime(struct ptp_clock_info *ptp,
struct timespec64 *ts)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u64 ns;
mutex_lock(&hellcreek->ptp_lock);
ns = __hellcreek_ptp_gettime(hellcreek);
mutex_unlock(&hellcreek->ptp_lock);
*ts = ns_to_timespec64(ns);
return 0;
}
static int hellcreek_ptp_settime(struct ptp_clock_info *ptp,
const struct timespec64 *ts)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u16 secl, nsh, nsl;
secl = ts->tv_sec & 0xffff;
nsh = ((u32)ts->tv_nsec & 0xffff0000) >> 16;
nsl = ts->tv_nsec & 0xffff;
mutex_lock(&hellcreek->ptp_lock);
/* Update overflow data structure */
hellcreek->seconds = ts->tv_sec;
hellcreek->last_ts = ts->tv_nsec;
/* Set time in clock */
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, secl, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, nsh, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, nsl, PR_CLOCK_WRITE_C);
mutex_unlock(&hellcreek->ptp_lock);
return 0;
}
static int hellcreek_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u16 negative = 0, addendh, addendl;
u32 addend;
u64 adj;
if (scaled_ppm < 0) {
negative = 1;
scaled_ppm = -scaled_ppm;
}
/* IP-Core adjusts the nominal frequency by adding or subtracting 1 ns
* from the 8 ns (period of the oscillator) every time the accumulator
* register overflows. The value stored in the addend register is added
* to the accumulator register every 8 ns.
*
* addend value = (2^30 * accumulator_overflow_rate) /
* oscillator_frequency
* where:
*
* oscillator_frequency = 125 MHz
* accumulator_overflow_rate = 125 MHz * scaled_ppm * 2^-16 * 10^-6 * 8
*/
adj = scaled_ppm;
adj <<= 11;
addend = (u32)div_u64(adj, 15625);
addendh = (addend & 0xffff0000) >> 16;
addendl = addend & 0xffff;
negative = (negative << 15) & 0x8000;
mutex_lock(&hellcreek->ptp_lock);
/* Set drift register */
hellcreek_ptp_write(hellcreek, negative, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, addendh, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, addendl, PR_CLOCK_DRIFT_C);
mutex_unlock(&hellcreek->ptp_lock);
return 0;
}
static int hellcreek_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u16 negative = 0, counth, countl;
u32 count_val;
/* If the offset is larger than IP-Core slow offset resources. Don't
* consider slow adjustment. Rather, add the offset directly to the
* current time
*/
if (abs(delta) > MAX_SLOW_OFFSET_ADJ) {
struct timespec64 now, then = ns_to_timespec64(delta);
hellcreek_ptp_gettime(ptp, &now);
now = timespec64_add(now, then);
hellcreek_ptp_settime(ptp, &now);
return 0;
}
if (delta < 0) {
negative = 1;
delta = -delta;
}
/* 'count_val' does not exceed the maximum register size (2^30) */
count_val = div_s64(delta, MAX_NS_PER_STEP);
counth = (count_val & 0xffff0000) >> 16;
countl = count_val & 0xffff;
negative = (negative << 15) & 0x8000;
mutex_lock(&hellcreek->ptp_lock);
/* Set offset write register */
hellcreek_ptp_write(hellcreek, negative, PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, MAX_NS_PER_STEP, PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, MIN_CLK_CYCLES_BETWEEN_STEPS,
PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, countl, PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, counth, PR_CLOCK_OFFSET_C);
mutex_unlock(&hellcreek->ptp_lock);
return 0;
}
static int hellcreek_ptp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
return -EOPNOTSUPP;
}
static void hellcreek_ptp_overflow_check(struct work_struct *work)
{
struct delayed_work *dw = to_delayed_work(work);
struct hellcreek *hellcreek;
hellcreek = dw_overflow_to_hellcreek(dw);
mutex_lock(&hellcreek->ptp_lock);
__hellcreek_ptp_gettime(hellcreek);
mutex_unlock(&hellcreek->ptp_lock);
schedule_delayed_work(&hellcreek->overflow_work,
HELLCREEK_OVERFLOW_PERIOD);
}
static enum led_brightness hellcreek_get_brightness(struct hellcreek *hellcreek,
int led)
{
return (hellcreek->status_out & led) ? 1 : 0;
}
static void hellcreek_set_brightness(struct hellcreek *hellcreek, int led,
enum led_brightness b)
{
mutex_lock(&hellcreek->ptp_lock);
if (b)
hellcreek->status_out |= led;
else
hellcreek->status_out &= ~led;
hellcreek_ptp_write(hellcreek, hellcreek->status_out, STATUS_OUT);
mutex_unlock(&hellcreek->ptp_lock);
}
static void hellcreek_led_sync_good_set(struct led_classdev *ldev,
enum led_brightness b)
{
struct hellcreek *hellcreek = led_to_hellcreek(ldev, led_sync_good);
hellcreek_set_brightness(hellcreek, STATUS_OUT_SYNC_GOOD, b);
}
static enum led_brightness hellcreek_led_sync_good_get(struct led_classdev *ldev)
{
struct hellcreek *hellcreek = led_to_hellcreek(ldev, led_sync_good);
return hellcreek_get_brightness(hellcreek, STATUS_OUT_SYNC_GOOD);
}
static void hellcreek_led_is_gm_set(struct led_classdev *ldev,
enum led_brightness b)
{
struct hellcreek *hellcreek = led_to_hellcreek(ldev, led_is_gm);
hellcreek_set_brightness(hellcreek, STATUS_OUT_IS_GM, b);
}
static enum led_brightness hellcreek_led_is_gm_get(struct led_classdev *ldev)
{
struct hellcreek *hellcreek = led_to_hellcreek(ldev, led_is_gm);
return hellcreek_get_brightness(hellcreek, STATUS_OUT_IS_GM);
}
/* There two available LEDs internally called sync_good and is_gm. However, the
* user might want to use a different label and specify the default state. Take
* those properties from device tree.
*/
static int hellcreek_led_setup(struct hellcreek *hellcreek)
{
struct device_node *leds, *led = NULL;
enum led_default_state state;
const char *label;
int ret = -EINVAL;
of_node_get(hellcreek->dev->of_node);
leds = of_find_node_by_name(hellcreek->dev->of_node, "leds");
if (!leds) {
dev_err(hellcreek->dev, "No LEDs specified in device tree!\n");
return ret;
}
hellcreek->status_out = 0;
led = of_get_next_available_child(leds, led);
if (!led) {
dev_err(hellcreek->dev, "First LED not specified!\n");
goto out;
}
ret = of_property_read_string(led, "label", &label);
hellcreek->led_sync_good.name = ret ? "sync_good" : label;
state = led_init_default_state_get(of_fwnode_handle(led));
switch (state) {
case LEDS_DEFSTATE_ON:
hellcreek->led_sync_good.brightness = 1;
break;
case LEDS_DEFSTATE_KEEP:
hellcreek->led_sync_good.brightness =
hellcreek_get_brightness(hellcreek, STATUS_OUT_SYNC_GOOD);
break;
default:
hellcreek->led_sync_good.brightness = 0;
}
hellcreek->led_sync_good.max_brightness = 1;
hellcreek->led_sync_good.brightness_set = hellcreek_led_sync_good_set;
hellcreek->led_sync_good.brightness_get = hellcreek_led_sync_good_get;
led = of_get_next_available_child(leds, led);
if (!led) {
dev_err(hellcreek->dev, "Second LED not specified!\n");
ret = -EINVAL;
goto out;
}
ret = of_property_read_string(led, "label", &label);
hellcreek->led_is_gm.name = ret ? "is_gm" : label;
state = led_init_default_state_get(of_fwnode_handle(led));
switch (state) {
case LEDS_DEFSTATE_ON:
hellcreek->led_is_gm.brightness = 1;
break;
case LEDS_DEFSTATE_KEEP:
hellcreek->led_is_gm.brightness =
hellcreek_get_brightness(hellcreek, STATUS_OUT_IS_GM);
break;
default:
hellcreek->led_is_gm.brightness = 0;
}
hellcreek->led_is_gm.max_brightness = 1;
hellcreek->led_is_gm.brightness_set = hellcreek_led_is_gm_set;
hellcreek->led_is_gm.brightness_get = hellcreek_led_is_gm_get;
/* Set initial state */
if (hellcreek->led_sync_good.brightness == 1)
hellcreek_set_brightness(hellcreek, STATUS_OUT_SYNC_GOOD, 1);
if (hellcreek->led_is_gm.brightness == 1)
hellcreek_set_brightness(hellcreek, STATUS_OUT_IS_GM, 1);
/* Register both leds */
led_classdev_register(hellcreek->dev, &hellcreek->led_sync_good);
led_classdev_register(hellcreek->dev, &hellcreek->led_is_gm);
ret = 0;
out:
of_node_put(leds);
return ret;
}
int hellcreek_ptp_setup(struct hellcreek *hellcreek)
{
u16 status;
int ret;
/* Set up the overflow work */
INIT_DELAYED_WORK(&hellcreek->overflow_work,
hellcreek_ptp_overflow_check);
/* Setup PTP clock */
hellcreek->ptp_clock_info.owner = THIS_MODULE;
snprintf(hellcreek->ptp_clock_info.name,
sizeof(hellcreek->ptp_clock_info.name),
dev_name(hellcreek->dev));
/* IP-Core can add up to 0.5 ns per 8 ns cycle, which means
* accumulator_overflow_rate shall not exceed 62.5 MHz (which adjusts
* the nominal frequency by 6.25%)
*/
hellcreek->ptp_clock_info.max_adj = 62500000;
hellcreek->ptp_clock_info.n_alarm = 0;
hellcreek->ptp_clock_info.n_pins = 0;
hellcreek->ptp_clock_info.n_ext_ts = 0;
hellcreek->ptp_clock_info.n_per_out = 0;
hellcreek->ptp_clock_info.pps = 0;
hellcreek->ptp_clock_info.adjfine = hellcreek_ptp_adjfine;
hellcreek->ptp_clock_info.adjtime = hellcreek_ptp_adjtime;
hellcreek->ptp_clock_info.gettime64 = hellcreek_ptp_gettime;
hellcreek->ptp_clock_info.settime64 = hellcreek_ptp_settime;
hellcreek->ptp_clock_info.enable = hellcreek_ptp_enable;
hellcreek->ptp_clock_info.do_aux_work = hellcreek_hwtstamp_work;
hellcreek->ptp_clock = ptp_clock_register(&hellcreek->ptp_clock_info,
hellcreek->dev);
if (IS_ERR(hellcreek->ptp_clock))
return PTR_ERR(hellcreek->ptp_clock);
/* Enable the offset correction process, if no offset correction is
* already taking place
*/
status = hellcreek_ptp_read(hellcreek, PR_CLOCK_STATUS_C);
if (!(status & PR_CLOCK_STATUS_C_OFS_ACT))
hellcreek_ptp_write(hellcreek,
status | PR_CLOCK_STATUS_C_ENA_OFS,
PR_CLOCK_STATUS_C);
/* Enable the drift correction process */
hellcreek_ptp_write(hellcreek, status | PR_CLOCK_STATUS_C_ENA_DRIFT,
PR_CLOCK_STATUS_C);
/* LED setup */
ret = hellcreek_led_setup(hellcreek);
if (ret) {
if (hellcreek->ptp_clock)
ptp_clock_unregister(hellcreek->ptp_clock);
return ret;
}
schedule_delayed_work(&hellcreek->overflow_work,
HELLCREEK_OVERFLOW_PERIOD);
return 0;
}
void hellcreek_ptp_free(struct hellcreek *hellcreek)
{
led_classdev_unregister(&hellcreek->led_is_gm);
led_classdev_unregister(&hellcreek->led_sync_good);
cancel_delayed_work_sync(&hellcreek->overflow_work);
if (hellcreek->ptp_clock)
ptp_clock_unregister(hellcreek->ptp_clock);
hellcreek->ptp_clock = NULL;
}