From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ... --- drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c | 457 +++++++++++++++++++++++++ 1 file changed, 457 insertions(+) create mode 100644 drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c (limited to 'drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c') diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c new file mode 100644 index 000000000..95862aff4 --- /dev/null +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c @@ -0,0 +1,457 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Marvell PP2.2 TAI support + * + * Note: + * Do NOT use the event capture support. + * Do Not even set the MPP muxes to allow PTP_EVENT_REQ to be used. + * It will disrupt the operation of this driver, and there is nothing + * that this driver can do to prevent that. Even using PTP_EVENT_REQ + * as an output will be seen as a trigger input, which can't be masked. + * When ever a trigger input is seen, the action in the TCFCR0_TCF + * field will be performed - whether it is a set, increment, decrement + * read, or frequency update. + * + * Other notes (useful, not specified in the documentation): + * - PTP_PULSE_OUT (PTP_EVENT_REQ MPP) + * It looks like the hardware can't generate a pulse at nsec=0. (The + * output doesn't trigger if the nsec field is zero.) + * Note: when configured as an output via the register at 0xfX441120, + * the input is still very much alive, and will trigger the current TCF + * function. + * - PTP_CLK_OUT (PTP_TRIG_GEN MPP) + * This generates a "PPS" signal determined by the CCC registers. It + * seems this is not aligned to the TOD counter in any way (it may be + * initially, but if you specify a non-round second interval, it won't, + * and you can't easily get it back.) + * - PTP_PCLK_OUT + * This generates a 50% duty cycle clock based on the TOD counter, and + * seems it can be set to any period of 1ns resolution. It is probably + * limited by the TOD step size. Its period is defined by the PCLK_CCC + * registers. Again, its alignment to the second is questionable. + * + * Consequently, we support none of these. + */ +#include +#include +#include + +#include "mvpp2.h" + +#define CR0_SW_NRESET BIT(0) + +#define TCFCR0_PHASE_UPDATE_ENABLE BIT(8) +#define TCFCR0_TCF_MASK (7 << 2) +#define TCFCR0_TCF_UPDATE (0 << 2) +#define TCFCR0_TCF_FREQUPDATE (1 << 2) +#define TCFCR0_TCF_INCREMENT (2 << 2) +#define TCFCR0_TCF_DECREMENT (3 << 2) +#define TCFCR0_TCF_CAPTURE (4 << 2) +#define TCFCR0_TCF_NOP (7 << 2) +#define TCFCR0_TCF_TRIGGER BIT(0) + +#define TCSR_CAPTURE_1_VALID BIT(1) +#define TCSR_CAPTURE_0_VALID BIT(0) + +struct mvpp2_tai { + struct ptp_clock_info caps; + struct ptp_clock *ptp_clock; + void __iomem *base; + spinlock_t lock; + u64 period; // nanosecond period in 32.32 fixed point + /* This timestamp is updated every two seconds */ + struct timespec64 stamp; +}; + +static void mvpp2_tai_modify(void __iomem *reg, u32 mask, u32 set) +{ + u32 val; + + val = readl_relaxed(reg) & ~mask; + val |= set & mask; + writel(val, reg); +} + +static void mvpp2_tai_write(u32 val, void __iomem *reg) +{ + writel_relaxed(val & 0xffff, reg); +} + +static u32 mvpp2_tai_read(void __iomem *reg) +{ + return readl_relaxed(reg) & 0xffff; +} + +static struct mvpp2_tai *ptp_to_tai(struct ptp_clock_info *ptp) +{ + return container_of(ptp, struct mvpp2_tai, caps); +} + +static void mvpp22_tai_read_ts(struct timespec64 *ts, void __iomem *base) +{ + ts->tv_sec = (u64)mvpp2_tai_read(base + 0) << 32 | + mvpp2_tai_read(base + 4) << 16 | + mvpp2_tai_read(base + 8); + + ts->tv_nsec = mvpp2_tai_read(base + 12) << 16 | + mvpp2_tai_read(base + 16); + + /* Read and discard fractional part */ + readl_relaxed(base + 20); + readl_relaxed(base + 24); +} + +static void mvpp2_tai_write_tlv(const struct timespec64 *ts, u32 frac, + void __iomem *base) +{ + mvpp2_tai_write(ts->tv_sec >> 32, base + MVPP22_TAI_TLV_SEC_HIGH); + mvpp2_tai_write(ts->tv_sec >> 16, base + MVPP22_TAI_TLV_SEC_MED); + mvpp2_tai_write(ts->tv_sec, base + MVPP22_TAI_TLV_SEC_LOW); + mvpp2_tai_write(ts->tv_nsec >> 16, base + MVPP22_TAI_TLV_NANO_HIGH); + mvpp2_tai_write(ts->tv_nsec, base + MVPP22_TAI_TLV_NANO_LOW); + mvpp2_tai_write(frac >> 16, base + MVPP22_TAI_TLV_FRAC_HIGH); + mvpp2_tai_write(frac, base + MVPP22_TAI_TLV_FRAC_LOW); +} + +static void mvpp2_tai_op(u32 op, void __iomem *base) +{ + /* Trigger the operation. Note that an external unmaskable + * event on PTP_EVENT_REQ will also trigger this action. + */ + mvpp2_tai_modify(base + MVPP22_TAI_TCFCR0, + TCFCR0_TCF_MASK | TCFCR0_TCF_TRIGGER, + op | TCFCR0_TCF_TRIGGER); + mvpp2_tai_modify(base + MVPP22_TAI_TCFCR0, TCFCR0_TCF_MASK, + TCFCR0_TCF_NOP); +} + +/* The adjustment has a range of +0.5ns to -0.5ns in 2^32 steps, so has units + * of 2^-32 ns. + * + * units(s) = 1 / (2^32 * 10^9) + * fractional = abs_scaled_ppm / (2^16 * 10^6) + * + * What we want to achieve: + * freq_adjusted = freq_nominal * (1 + fractional) + * freq_delta = freq_adjusted - freq_nominal => positive = faster + * freq_delta = freq_nominal * (1 + fractional) - freq_nominal + * So: freq_delta = freq_nominal * fractional + * + * However, we are dealing with periods, so: + * period_adjusted = period_nominal / (1 + fractional) + * period_delta = period_nominal - period_adjusted => positive = faster + * period_delta = period_nominal * fractional / (1 + fractional) + * + * Hence: + * period_delta = period_nominal * abs_scaled_ppm / + * (2^16 * 10^6 + abs_scaled_ppm) + * + * To avoid overflow, we reduce both sides of the divide operation by a factor + * of 16. + */ +static u64 mvpp22_calc_frac_ppm(struct mvpp2_tai *tai, long abs_scaled_ppm) +{ + u64 val = tai->period * abs_scaled_ppm >> 4; + + return div_u64(val, (1000000 << 12) + (abs_scaled_ppm >> 4)); +} + +static s32 mvpp22_calc_max_adj(struct mvpp2_tai *tai) +{ + return 1000000; +} + +static int mvpp22_tai_adjfine(struct ptp_clock_info *ptp, long scaled_ppm) +{ + struct mvpp2_tai *tai = ptp_to_tai(ptp); + unsigned long flags; + void __iomem *base; + bool neg_adj; + s32 frac; + u64 val; + + neg_adj = scaled_ppm < 0; + if (neg_adj) + scaled_ppm = -scaled_ppm; + + val = mvpp22_calc_frac_ppm(tai, scaled_ppm); + + /* Convert to a signed 32-bit adjustment */ + if (neg_adj) { + /* -S32_MIN warns, -val < S32_MIN fails, so go for the easy + * solution. + */ + if (val > 0x80000000) + return -ERANGE; + + frac = -val; + } else { + if (val > S32_MAX) + return -ERANGE; + + frac = val; + } + + base = tai->base; + spin_lock_irqsave(&tai->lock, flags); + mvpp2_tai_write(frac >> 16, base + MVPP22_TAI_TLV_FRAC_HIGH); + mvpp2_tai_write(frac, base + MVPP22_TAI_TLV_FRAC_LOW); + mvpp2_tai_op(TCFCR0_TCF_FREQUPDATE, base); + spin_unlock_irqrestore(&tai->lock, flags); + + return 0; +} + +static int mvpp22_tai_adjtime(struct ptp_clock_info *ptp, s64 delta) +{ + struct mvpp2_tai *tai = ptp_to_tai(ptp); + struct timespec64 ts; + unsigned long flags; + void __iomem *base; + u32 tcf; + + /* We can't deal with S64_MIN */ + if (delta == S64_MIN) + return -ERANGE; + + if (delta < 0) { + delta = -delta; + tcf = TCFCR0_TCF_DECREMENT; + } else { + tcf = TCFCR0_TCF_INCREMENT; + } + + ts = ns_to_timespec64(delta); + + base = tai->base; + spin_lock_irqsave(&tai->lock, flags); + mvpp2_tai_write_tlv(&ts, 0, base); + mvpp2_tai_op(tcf, base); + spin_unlock_irqrestore(&tai->lock, flags); + + return 0; +} + +static int mvpp22_tai_gettimex64(struct ptp_clock_info *ptp, + struct timespec64 *ts, + struct ptp_system_timestamp *sts) +{ + struct mvpp2_tai *tai = ptp_to_tai(ptp); + unsigned long flags; + void __iomem *base; + u32 tcsr; + int ret; + + base = tai->base; + spin_lock_irqsave(&tai->lock, flags); + /* XXX: the only way to read the PTP time is for the CPU to trigger + * an event. However, there is no way to distinguish between the CPU + * triggered event, and an external event on PTP_EVENT_REQ. So this + * is incompatible with external use of PTP_EVENT_REQ. + */ + ptp_read_system_prets(sts); + mvpp2_tai_modify(base + MVPP22_TAI_TCFCR0, + TCFCR0_TCF_MASK | TCFCR0_TCF_TRIGGER, + TCFCR0_TCF_CAPTURE | TCFCR0_TCF_TRIGGER); + ptp_read_system_postts(sts); + mvpp2_tai_modify(base + MVPP22_TAI_TCFCR0, TCFCR0_TCF_MASK, + TCFCR0_TCF_NOP); + + tcsr = readl(base + MVPP22_TAI_TCSR); + if (tcsr & TCSR_CAPTURE_1_VALID) { + mvpp22_tai_read_ts(ts, base + MVPP22_TAI_TCV1_SEC_HIGH); + ret = 0; + } else if (tcsr & TCSR_CAPTURE_0_VALID) { + mvpp22_tai_read_ts(ts, base + MVPP22_TAI_TCV0_SEC_HIGH); + ret = 0; + } else { + /* We don't seem to have a reading... */ + ret = -EBUSY; + } + spin_unlock_irqrestore(&tai->lock, flags); + + return ret; +} + +static int mvpp22_tai_settime64(struct ptp_clock_info *ptp, + const struct timespec64 *ts) +{ + struct mvpp2_tai *tai = ptp_to_tai(ptp); + unsigned long flags; + void __iomem *base; + + base = tai->base; + spin_lock_irqsave(&tai->lock, flags); + mvpp2_tai_write_tlv(ts, 0, base); + + /* Trigger an update to load the value from the TLV registers + * into the TOD counter. Note that an external unmaskable event on + * PTP_EVENT_REQ will also trigger this action. + */ + mvpp2_tai_modify(base + MVPP22_TAI_TCFCR0, + TCFCR0_PHASE_UPDATE_ENABLE | + TCFCR0_TCF_MASK | TCFCR0_TCF_TRIGGER, + TCFCR0_TCF_UPDATE | TCFCR0_TCF_TRIGGER); + mvpp2_tai_modify(base + MVPP22_TAI_TCFCR0, TCFCR0_TCF_MASK, + TCFCR0_TCF_NOP); + spin_unlock_irqrestore(&tai->lock, flags); + + return 0; +} + +static long mvpp22_tai_aux_work(struct ptp_clock_info *ptp) +{ + struct mvpp2_tai *tai = ptp_to_tai(ptp); + + mvpp22_tai_gettimex64(ptp, &tai->stamp, NULL); + + return msecs_to_jiffies(2000); +} + +static void mvpp22_tai_set_step(struct mvpp2_tai *tai) +{ + void __iomem *base = tai->base; + u32 nano, frac; + + nano = upper_32_bits(tai->period); + frac = lower_32_bits(tai->period); + + /* As the fractional nanosecond is a signed offset, if the MSB (sign) + * bit is set, we have to increment the whole nanoseconds. + */ + if (frac >= 0x80000000) + nano += 1; + + mvpp2_tai_write(nano, base + MVPP22_TAI_TOD_STEP_NANO_CR); + mvpp2_tai_write(frac >> 16, base + MVPP22_TAI_TOD_STEP_FRAC_HIGH); + mvpp2_tai_write(frac, base + MVPP22_TAI_TOD_STEP_FRAC_LOW); +} + +static void mvpp22_tai_init(struct mvpp2_tai *tai) +{ + void __iomem *base = tai->base; + + mvpp22_tai_set_step(tai); + + /* Release the TAI reset */ + mvpp2_tai_modify(base + MVPP22_TAI_CR0, CR0_SW_NRESET, CR0_SW_NRESET); +} + +int mvpp22_tai_ptp_clock_index(struct mvpp2_tai *tai) +{ + return ptp_clock_index(tai->ptp_clock); +} + +void mvpp22_tai_tstamp(struct mvpp2_tai *tai, u32 tstamp, + struct skb_shared_hwtstamps *hwtstamp) +{ + struct timespec64 ts; + int delta; + + /* The tstamp consists of 2 bits of seconds and 30 bits of nanoseconds. + * We use our stored timestamp (tai->stamp) to form a full timestamp, + * and we must read the seconds exactly once. + */ + ts.tv_sec = READ_ONCE(tai->stamp.tv_sec); + ts.tv_nsec = tstamp & 0x3fffffff; + + /* Calculate the delta in seconds between our stored timestamp and + * the value read from the queue. Allow timestamps one second in the + * past, otherwise consider them to be in the future. + */ + delta = ((tstamp >> 30) - (ts.tv_sec & 3)) & 3; + if (delta == 3) + delta -= 4; + ts.tv_sec += delta; + + memset(hwtstamp, 0, sizeof(*hwtstamp)); + hwtstamp->hwtstamp = timespec64_to_ktime(ts); +} + +void mvpp22_tai_start(struct mvpp2_tai *tai) +{ + long delay; + + delay = mvpp22_tai_aux_work(&tai->caps); + + ptp_schedule_worker(tai->ptp_clock, delay); +} + +void mvpp22_tai_stop(struct mvpp2_tai *tai) +{ + ptp_cancel_worker_sync(tai->ptp_clock); +} + +static void mvpp22_tai_remove(void *priv) +{ + struct mvpp2_tai *tai = priv; + + if (!IS_ERR(tai->ptp_clock)) + ptp_clock_unregister(tai->ptp_clock); +} + +int mvpp22_tai_probe(struct device *dev, struct mvpp2 *priv) +{ + struct mvpp2_tai *tai; + int ret; + + tai = devm_kzalloc(dev, sizeof(*tai), GFP_KERNEL); + if (!tai) + return -ENOMEM; + + spin_lock_init(&tai->lock); + + tai->base = priv->iface_base; + + /* The step size consists of three registers - a 16-bit nanosecond step + * size, and a 32-bit fractional nanosecond step size split over two + * registers. The fractional nanosecond step size has units of 2^-32ns. + * + * To calculate this, we calculate: + * (10^9 + freq / 2) / (freq * 2^-32) + * which gives us the nanosecond step to the nearest integer in 16.32 + * fixed point format, and the fractional part of the step size with + * the MSB inverted. With rounding of the fractional nanosecond, and + * simplification, this becomes: + * (10^9 << 32 + freq << 31 + (freq + 1) >> 1) / freq + * + * So: + * div = (10^9 << 32 + freq << 31 + (freq + 1) >> 1) / freq + * nano = upper_32_bits(div); + * frac = lower_32_bits(div) ^ 0x80000000; + * Will give the values for the registers. + * + * This is all seems perfect, but alas it is not when considering the + * whole story. The system is clocked from 25MHz, which is multiplied + * by a PLL to 1GHz, and then divided by three, giving 333333333Hz + * (recurring). This gives exactly 3ns, but using 333333333Hz with + * the above gives an error of 13*2^-32ns. + * + * Consequently, we use the period rather than calculating from the + * frequency. + */ + tai->period = 3ULL << 32; + + mvpp22_tai_init(tai); + + tai->caps.owner = THIS_MODULE; + strscpy(tai->caps.name, "Marvell PP2.2", sizeof(tai->caps.name)); + tai->caps.max_adj = mvpp22_calc_max_adj(tai); + tai->caps.adjfine = mvpp22_tai_adjfine; + tai->caps.adjtime = mvpp22_tai_adjtime; + tai->caps.gettimex64 = mvpp22_tai_gettimex64; + tai->caps.settime64 = mvpp22_tai_settime64; + tai->caps.do_aux_work = mvpp22_tai_aux_work; + + ret = devm_add_action(dev, mvpp22_tai_remove, tai); + if (ret) + return ret; + + tai->ptp_clock = ptp_clock_register(&tai->caps, dev); + if (IS_ERR(tai->ptp_clock)) + return PTR_ERR(tai->ptp_clock); + + priv->tai = tai; + + return 0; +} -- cgit v1.2.3