diff options
Diffstat (limited to 'drivers/net/dsa/hirschmann/hellcreek_ptp.c')
| -rw-r--r-- | drivers/net/dsa/hirschmann/hellcreek_ptp.c | 453 |
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; +} |