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Diffstat (limited to 'drivers/net/dsa/hirschmann/hellcreek_ptp.c')
-rw-r--r--drivers/net/dsa/hirschmann/hellcreek_ptp.c453
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/net/dsa/hirschmann/hellcreek_ptp.c b/drivers/net/dsa/hirschmann/hellcreek_ptp.c
new file mode 100644
index 000000000..b28baab6d
--- /dev/null
+++ b/drivers/net/dsa/hirschmann/hellcreek_ptp.c
@@ -0,0 +1,453 @@
+// 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/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;
+ const char *label, *state;
+ 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;
+
+ ret = of_property_read_string(led, "default-state", &state);
+ if (!ret) {
+ if (!strcmp(state, "on"))
+ hellcreek->led_sync_good.brightness = 1;
+ else if (!strcmp(state, "off"))
+ hellcreek->led_sync_good.brightness = 0;
+ else if (!strcmp(state, "keep"))
+ hellcreek->led_sync_good.brightness =
+ hellcreek_get_brightness(hellcreek,
+ STATUS_OUT_SYNC_GOOD);
+ }
+
+ 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;
+
+ ret = of_property_read_string(led, "default-state", &state);
+ if (!ret) {
+ if (!strcmp(state, "on"))
+ hellcreek->led_is_gm.brightness = 1;
+ else if (!strcmp(state, "off"))
+ hellcreek->led_is_gm.brightness = 0;
+ else if (!strcmp(state, "keep"))
+ hellcreek->led_is_gm.brightness =
+ hellcreek_get_brightness(hellcreek,
+ STATUS_OUT_IS_GM);
+ }
+
+ 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;
+}