diff options
| -rw-r--r-- | drivers/net/ethernet/marvell/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/net/ethernet/marvell/mvpp2/Makefile | 3 | ||||
| -rw-r--r-- | drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 109 | ||||
| -rw-r--r-- | drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 | ||||
| -rw-r--r-- | drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c | 400 |
5 files changed, 521 insertions, 1 deletions
diff --git a/drivers/net/ethernet/marvell/Kconfig b/drivers/net/ethernet/marvell/Kconfig index 20415893ba4a..ce904a725500 100644 --- a/drivers/net/ethernet/marvell/Kconfig +++ b/drivers/net/ethernet/marvell/Kconfig @@ -95,6 +95,12 @@ config MVPP2 This driver supports the network interface units in the Marvell ARMADA 375, 7K and 8K SoCs. +config MVPP2_PTP + bool "Marvell Armada 8K Enable PTP support" + depends on NETWORK_PHY_TIMESTAMPING + depends on (PTP_1588_CLOCK = y && MVPP2 = y) || \ + (PTP_1588_CLOCK && MVPP2 = m) + config PXA168_ETH tristate "Marvell pxa168 ethernet support" depends on HAS_IOMEM diff --git a/drivers/net/ethernet/marvell/mvpp2/Makefile b/drivers/net/ethernet/marvell/mvpp2/Makefile index 51f65a202c6e..9bd8e7964b40 100644 --- a/drivers/net/ethernet/marvell/mvpp2/Makefile +++ b/drivers/net/ethernet/marvell/mvpp2/Makefile @@ -4,4 +4,5 @@ # obj-$(CONFIG_MVPP2) := mvpp2.o -mvpp2-objs := mvpp2_main.o mvpp2_prs.o mvpp2_cls.o mvpp2_debugfs.o +mvpp2-y := mvpp2_main.o mvpp2_prs.o mvpp2_cls.o mvpp2_debugfs.o +mvpp2-$(CONFIG_MVPP2_PTP) += mvpp2_tai.o diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h index c0192d68766f..3e85cd1f9f3a 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h @@ -492,6 +492,70 @@ #define MVPP22_SMI_MISC_CFG_REG 0x1204 #define MVPP22_SMI_POLLING_EN BIT(10) +/* TAI registers, PPv2.2 only, relative to priv->iface_base */ +#define MVPP22_TAI_INT_CAUSE 0x1400 +#define MVPP22_TAI_INT_MASK 0x1404 +#define MVPP22_TAI_CR0 0x1408 +#define MVPP22_TAI_CR1 0x140c +#define MVPP22_TAI_TCFCR0 0x1410 +#define MVPP22_TAI_TCFCR1 0x1414 +#define MVPP22_TAI_TCFCR2 0x1418 +#define MVPP22_TAI_FATWR 0x141c +#define MVPP22_TAI_TOD_STEP_NANO_CR 0x1420 +#define MVPP22_TAI_TOD_STEP_FRAC_HIGH 0x1424 +#define MVPP22_TAI_TOD_STEP_FRAC_LOW 0x1428 +#define MVPP22_TAI_TAPDC_HIGH 0x142c +#define MVPP22_TAI_TAPDC_LOW 0x1430 +#define MVPP22_TAI_TGTOD_SEC_HIGH 0x1434 +#define MVPP22_TAI_TGTOD_SEC_MED 0x1438 +#define MVPP22_TAI_TGTOD_SEC_LOW 0x143c +#define MVPP22_TAI_TGTOD_NANO_HIGH 0x1440 +#define MVPP22_TAI_TGTOD_NANO_LOW 0x1444 +#define MVPP22_TAI_TGTOD_FRAC_HIGH 0x1448 +#define MVPP22_TAI_TGTOD_FRAC_LOW 0x144c +#define MVPP22_TAI_TLV_SEC_HIGH 0x1450 +#define MVPP22_TAI_TLV_SEC_MED 0x1454 +#define MVPP22_TAI_TLV_SEC_LOW 0x1458 +#define MVPP22_TAI_TLV_NANO_HIGH 0x145c +#define MVPP22_TAI_TLV_NANO_LOW 0x1460 +#define MVPP22_TAI_TLV_FRAC_HIGH 0x1464 +#define MVPP22_TAI_TLV_FRAC_LOW 0x1468 +#define MVPP22_TAI_TCV0_SEC_HIGH 0x146c +#define MVPP22_TAI_TCV0_SEC_MED 0x1470 +#define MVPP22_TAI_TCV0_SEC_LOW 0x1474 +#define MVPP22_TAI_TCV0_NANO_HIGH 0x1478 +#define MVPP22_TAI_TCV0_NANO_LOW 0x147c +#define MVPP22_TAI_TCV0_FRAC_HIGH 0x1480 +#define MVPP22_TAI_TCV0_FRAC_LOW 0x1484 +#define MVPP22_TAI_TCV1_SEC_HIGH 0x1488 +#define MVPP22_TAI_TCV1_SEC_MED 0x148c +#define MVPP22_TAI_TCV1_SEC_LOW 0x1490 +#define MVPP22_TAI_TCV1_NANO_HIGH 0x1494 +#define MVPP22_TAI_TCV1_NANO_LOW 0x1498 +#define MVPP22_TAI_TCV1_FRAC_HIGH 0x149c +#define MVPP22_TAI_TCV1_FRAC_LOW 0x14a0 +#define MVPP22_TAI_TCSR 0x14a4 +#define MVPP22_TAI_TUC_LSB 0x14a8 +#define MVPP22_TAI_GFM_SEC_HIGH 0x14ac +#define MVPP22_TAI_GFM_SEC_MED 0x14b0 +#define MVPP22_TAI_GFM_SEC_LOW 0x14b4 +#define MVPP22_TAI_GFM_NANO_HIGH 0x14b8 +#define MVPP22_TAI_GFM_NANO_LOW 0x14bc +#define MVPP22_TAI_GFM_FRAC_HIGH 0x14c0 +#define MVPP22_TAI_GFM_FRAC_LOW 0x14c4 +#define MVPP22_TAI_PCLK_DA_HIGH 0x14c8 +#define MVPP22_TAI_PCLK_DA_LOW 0x14cc +#define MVPP22_TAI_CTCR 0x14d0 +#define MVPP22_TAI_PCLK_CCC_HIGH 0x14d4 +#define MVPP22_TAI_PCLK_CCC_LOW 0x14d8 +#define MVPP22_TAI_DTC_HIGH 0x14dc +#define MVPP22_TAI_DTC_LOW 0x14e0 +#define MVPP22_TAI_CCC_HIGH 0x14e4 +#define MVPP22_TAI_CCC_LOW 0x14e8 +#define MVPP22_TAI_ICICE 0x14f4 +#define MVPP22_TAI_ICICC_LOW 0x14f8 +#define MVPP22_TAI_TUC_MSB 0x14fc + #define MVPP22_GMAC_BASE(port) (0x7000 + (port) * 0x1000 + 0xe00) #define MVPP2_CAUSE_TXQ_SENT_DESC_ALL_MASK 0xff @@ -518,6 +582,39 @@ #define MVPP22_XPCS_CFG0_PCS_MODE(n) ((n) << 3) #define MVPP22_XPCS_CFG0_ACTIVE_LANE(n) ((n) << 5) +/* PTP registers. PPv2.2 only */ +#define MVPP22_PTP_BASE(port) (0x7800 + (port * 0x1000)) +#define MVPP22_PTP_INT_CAUSE 0x00 +#define MVPP22_PTP_INT_MASK 0x04 +#define MVPP22_PTP_GCR 0x08 +#define MVPP22_PTP_TX_Q0_R0 0x0c +#define MVPP22_PTP_TX_Q0_R1 0x10 +#define MVPP22_PTP_TX_Q0_R2 0x14 +#define MVPP22_PTP_TX_Q1_R0 0x18 +#define MVPP22_PTP_TX_Q1_R1 0x1c +#define MVPP22_PTP_TX_Q1_R2 0x20 +#define MVPP22_PTP_TPCR 0x24 +#define MVPP22_PTP_V1PCR 0x28 +#define MVPP22_PTP_V2PCR 0x2c +#define MVPP22_PTP_Y1731PCR 0x30 +#define MVPP22_PTP_NTPTSPCR 0x34 +#define MVPP22_PTP_NTPRXPCR 0x38 +#define MVPP22_PTP_NTPTXPCR 0x3c +#define MVPP22_PTP_WAMPPCR 0x40 +#define MVPP22_PTP_NAPCR 0x44 +#define MVPP22_PTP_FAPCR 0x48 +#define MVPP22_PTP_CAPCR 0x50 +#define MVPP22_PTP_ATAPCR 0x54 +#define MVPP22_PTP_ACTAPCR 0x58 +#define MVPP22_PTP_CATAPCR 0x5c +#define MVPP22_PTP_CACTAPCR 0x60 +#define MVPP22_PTP_AITAPCR 0x64 +#define MVPP22_PTP_CAITAPCR 0x68 +#define MVPP22_PTP_CITAPCR 0x6c +#define MVPP22_PTP_NTP_OFF_HIGH 0x70 +#define MVPP22_PTP_NTP_OFF_LOW 0x74 +#define MVPP22_PTP_TX_PIPE_STATUS_DELAY 0x78 + /* System controller registers. Accessed through a regmap. */ #define GENCONF_SOFT_RESET1 0x1108 #define GENCONF_SOFT_RESET1_GOP BIT(6) @@ -748,6 +845,8 @@ enum mvpp2_prs_l3_cast { #define MVPP2_DESC_DMA_MASK DMA_BIT_MASK(40) +struct mvpp2_tai; + /* Definitions */ struct mvpp2_dbgfs_entries; @@ -783,6 +882,7 @@ struct mvpp2 { /* List of pointers to port structures */ int port_count; struct mvpp2_port *port_list[MVPP2_MAX_PORTS]; + struct mvpp2_tai *tai; /* Number of Tx threads used */ unsigned int nthreads; @@ -1208,4 +1308,13 @@ void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name); void mvpp2_dbgfs_cleanup(struct mvpp2 *priv); +#ifdef CONFIG_MVPP2_PTP +int mvpp22_tai_probe(struct device *dev, struct mvpp2 *priv); +#else +static inline int mvpp22_tai_probe(struct device *dev, struct mvpp2 *priv) +{ + return 0; +} +#endif + #endif diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 06ef0effcd1e..53f147a6a8e2 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -6088,6 +6088,10 @@ static int mvpp2_probe(struct platform_device *pdev) goto err_axi_clk; } + err = mvpp22_tai_probe(&pdev->dev, priv); + if (err < 0) + goto err_axi_clk; + /* Initialize ports */ fwnode_for_each_available_child_node(fwnode, port_fwnode) { err = mvpp2_port_probe(pdev, port_fwnode, priv); 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 000000000000..86c94ca97e43 --- /dev/null +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c @@ -0,0 +1,400 @@ +// 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 <linux/io.h> +#include <linux/ptp_clock_kernel.h> +#include <linux/slab.h> + +#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 +}; + +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 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); +} + +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; + + 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; +} |