// SPDX-License-Identifier: GPL-2.0 /* * Fast Ethernet Controller (ENET) PTP driver for MX6x. * * Copyright (C) 2012 Freescale Semiconductor, Inc. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fec.h" /* FEC 1588 register bits */ #define FEC_T_CTRL_SLAVE 0x00002000 #define FEC_T_CTRL_CAPTURE 0x00000800 #define FEC_T_CTRL_RESTART 0x00000200 #define FEC_T_CTRL_PERIOD_RST 0x00000030 #define FEC_T_CTRL_PERIOD_EN 0x00000010 #define FEC_T_CTRL_ENABLE 0x00000001 #define FEC_T_INC_MASK 0x0000007f #define FEC_T_INC_OFFSET 0 #define FEC_T_INC_CORR_MASK 0x00007f00 #define FEC_T_INC_CORR_OFFSET 8 #define FEC_T_CTRL_PINPER 0x00000080 #define FEC_T_TF0_MASK 0x00000001 #define FEC_T_TF0_OFFSET 0 #define FEC_T_TF1_MASK 0x00000002 #define FEC_T_TF1_OFFSET 1 #define FEC_T_TF2_MASK 0x00000004 #define FEC_T_TF2_OFFSET 2 #define FEC_T_TF3_MASK 0x00000008 #define FEC_T_TF3_OFFSET 3 #define FEC_T_TDRE_MASK 0x00000001 #define FEC_T_TDRE_OFFSET 0 #define FEC_T_TMODE_MASK 0x0000003C #define FEC_T_TMODE_OFFSET 2 #define FEC_T_TIE_MASK 0x00000040 #define FEC_T_TIE_OFFSET 6 #define FEC_T_TF_MASK 0x00000080 #define FEC_T_TF_OFFSET 7 #define FEC_ATIME_CTRL 0x400 #define FEC_ATIME 0x404 #define FEC_ATIME_EVT_OFFSET 0x408 #define FEC_ATIME_EVT_PERIOD 0x40c #define FEC_ATIME_CORR 0x410 #define FEC_ATIME_INC 0x414 #define FEC_TS_TIMESTAMP 0x418 #define FEC_TGSR 0x604 #define FEC_TCSR(n) (0x608 + n * 0x08) #define FEC_TCCR(n) (0x60C + n * 0x08) #define MAX_TIMER_CHANNEL 3 #define FEC_TMODE_TOGGLE 0x05 #define FEC_HIGH_PULSE 0x0F #define FEC_CC_MULT (1 << 31) #define FEC_COUNTER_PERIOD (1 << 31) #define PPS_OUPUT_RELOAD_PERIOD NSEC_PER_SEC #define FEC_CHANNLE_0 0 #define DEFAULT_PPS_CHANNEL FEC_CHANNLE_0 /** * fec_ptp_enable_pps * @fep: the fec_enet_private structure handle * @enable: enable the channel pps output * * This function enble the PPS ouput on the timer channel. */ static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable) { unsigned long flags; u32 val, tempval; struct timespec64 ts; u64 ns; val = 0; if (!(fep->hwts_tx_en || fep->hwts_rx_en)) { dev_err(&fep->pdev->dev, "No ptp stack is running\n"); return -EINVAL; } if (fep->pps_enable == enable) return 0; fep->pps_channel = DEFAULT_PPS_CHANNEL; fep->reload_period = PPS_OUPUT_RELOAD_PERIOD; spin_lock_irqsave(&fep->tmreg_lock, flags); if (enable) { /* clear capture or output compare interrupt status if have. */ writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel)); /* It is recommended to double check the TMODE field in the * TCSR register to be cleared before the first compare counter * is written into TCCR register. Just add a double check. */ val = readl(fep->hwp + FEC_TCSR(fep->pps_channel)); do { val &= ~(FEC_T_TMODE_MASK); writel(val, fep->hwp + FEC_TCSR(fep->pps_channel)); val = readl(fep->hwp + FEC_TCSR(fep->pps_channel)); } while (val & FEC_T_TMODE_MASK); /* Dummy read counter to update the counter */ timecounter_read(&fep->tc); /* We want to find the first compare event in the next * second point. So we need to know what the ptp time * is now and how many nanoseconds is ahead to get next second. * The remaining nanosecond ahead before the next second would be * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds * to current timer would be next second. */ tempval = readl(fep->hwp + FEC_ATIME_CTRL); tempval |= FEC_T_CTRL_CAPTURE; writel(tempval, fep->hwp + FEC_ATIME_CTRL); tempval = readl(fep->hwp + FEC_ATIME); /* Convert the ptp local counter to 1588 timestamp */ ns = timecounter_cyc2time(&fep->tc, tempval); ts = ns_to_timespec64(ns); /* The tempval is less than 3 seconds, and so val is less than * 4 seconds. No overflow for 32bit calculation. */ val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval; /* Need to consider the situation that the current time is * very close to the second point, which means NSEC_PER_SEC * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer * is still running when we calculate the first compare event, it is * possible that the remaining nanoseonds run out before the compare * counter is calculated and written into TCCR register. To avoid * this possibility, we will set the compare event to be the next * of next second. The current setting is 31-bit timer and wrap * around over 2 seconds. So it is okay to set the next of next * seond for the timer. */ val += NSEC_PER_SEC; /* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current * ptp counter, which maybe cause 32-bit wrap. Since the * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second. * We can ensure the wrap will not cause issue. If the offset * is bigger than fep->cc.mask would be a error. */ val &= fep->cc.mask; writel(val, fep->hwp + FEC_TCCR(fep->pps_channel)); /* Calculate the second the compare event timestamp */ fep->next_counter = (val + fep->reload_period) & fep->cc.mask; /* * Enable compare event when overflow */ val = readl(fep->hwp + FEC_ATIME_CTRL); val |= FEC_T_CTRL_PINPER; writel(val, fep->hwp + FEC_ATIME_CTRL); /* Compare channel setting. */ val = readl(fep->hwp + FEC_TCSR(fep->pps_channel)); val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET); val &= ~(1 << FEC_T_TDRE_OFFSET); val &= ~(FEC_T_TMODE_MASK); val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET); writel(val, fep->hwp + FEC_TCSR(fep->pps_channel)); /* Write the second compare event timestamp and calculate * the third timestamp. Refer the TCCR register detail in the spec. */ writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel)); fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask; } else { writel(0, fep->hwp + FEC_TCSR(fep->pps_channel)); } fep->pps_enable = enable; spin_unlock_irqrestore(&fep->tmreg_lock, flags); return 0; } /** * fec_ptp_read - read raw cycle counter (to be used by time counter) * @cc: the cyclecounter structure * * this function reads the cyclecounter registers and is called by the * cyclecounter structure used to construct a ns counter from the * arbitrary fixed point registers */ static u64 fec_ptp_read(const struct cyclecounter *cc) { struct fec_enet_private *fep = container_of(cc, struct fec_enet_private, cc); const struct platform_device_id *id_entry = platform_get_device_id(fep->pdev); u32 tempval; tempval = readl(fep->hwp + FEC_ATIME_CTRL); tempval |= FEC_T_CTRL_CAPTURE; writel(tempval, fep->hwp + FEC_ATIME_CTRL); if (id_entry->driver_data & FEC_QUIRK_BUG_CAPTURE) udelay(1); return readl(fep->hwp + FEC_ATIME); } /** * fec_ptp_start_cyclecounter - create the cycle counter from hw * @ndev: network device * * this function initializes the timecounter and cyclecounter * structures for use in generated a ns counter from the arbitrary * fixed point cycles registers in the hardware. */ void fec_ptp_start_cyclecounter(struct net_device *ndev) { struct fec_enet_private *fep = netdev_priv(ndev); unsigned long flags; int inc; inc = 1000000000 / fep->cycle_speed; /* grab the ptp lock */ spin_lock_irqsave(&fep->tmreg_lock, flags); /* 1ns counter */ writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC); /* use 31-bit timer counter */ writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD); writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST, fep->hwp + FEC_ATIME_CTRL); memset(&fep->cc, 0, sizeof(fep->cc)); fep->cc.read = fec_ptp_read; fep->cc.mask = CLOCKSOURCE_MASK(31); fep->cc.shift = 31; fep->cc.mult = FEC_CC_MULT; /* reset the ns time counter */ timecounter_init(&fep->tc, &fep->cc, ktime_to_ns(ktime_get_real())); spin_unlock_irqrestore(&fep->tmreg_lock, flags); } /** * fec_ptp_adjfreq - adjust ptp cycle frequency * @ptp: the ptp clock structure * @ppb: parts per billion adjustment from base * * Adjust the frequency of the ptp cycle counter by the * indicated ppb from the base frequency. * * Because ENET hardware frequency adjust is complex, * using software method to do that. */ static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) { unsigned long flags; int neg_adj = 0; u32 i, tmp; u32 corr_inc, corr_period; u32 corr_ns; u64 lhs, rhs; struct fec_enet_private *fep = container_of(ptp, struct fec_enet_private, ptp_caps); if (ppb == 0) return 0; if (ppb < 0) { ppb = -ppb; neg_adj = 1; } /* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC; * Try to find the corr_inc between 1 to fep->ptp_inc to * meet adjustment requirement. */ lhs = NSEC_PER_SEC; rhs = (u64)ppb * (u64)fep->ptp_inc; for (i = 1; i <= fep->ptp_inc; i++) { if (lhs >= rhs) { corr_inc = i; corr_period = div_u64(lhs, rhs); break; } lhs += NSEC_PER_SEC; } /* Not found? Set it to high value - double speed * correct in every clock step. */ if (i > fep->ptp_inc) { corr_inc = fep->ptp_inc; corr_period = 1; } if (neg_adj) corr_ns = fep->ptp_inc - corr_inc; else corr_ns = fep->ptp_inc + corr_inc; spin_lock_irqsave(&fep->tmreg_lock, flags); tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK; tmp |= corr_ns << FEC_T_INC_CORR_OFFSET; writel(tmp, fep->hwp + FEC_ATIME_INC); corr_period = corr_period > 1 ? corr_period - 1 : corr_period; writel(corr_period, fep->hwp + FEC_ATIME_CORR); /* dummy read to update the timer. */ timecounter_read(&fep->tc); spin_unlock_irqrestore(&fep->tmreg_lock, flags); return 0; } /** * fec_ptp_adjtime * @ptp: the ptp clock structure * @delta: offset to adjust the cycle counter by * * adjust the timer by resetting the timecounter structure. */ static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) { struct fec_enet_private *fep = container_of(ptp, struct fec_enet_private, ptp_caps); unsigned long flags; spin_lock_irqsave(&fep->tmreg_lock, flags); timecounter_adjtime(&fep->tc, delta); spin_unlock_irqrestore(&fep->tmreg_lock, flags); return 0; } /** * fec_ptp_gettime * @ptp: the ptp clock structure * @ts: timespec structure to hold the current time value * * read the timecounter and return the correct value on ns, * after converting it into a struct timespec. */ static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) { struct fec_enet_private *adapter = container_of(ptp, struct fec_enet_private, ptp_caps); u64 ns; unsigned long flags; mutex_lock(&adapter->ptp_clk_mutex); /* Check the ptp clock */ if (!adapter->ptp_clk_on) { mutex_unlock(&adapter->ptp_clk_mutex); return -EINVAL; } spin_lock_irqsave(&adapter->tmreg_lock, flags); ns = timecounter_read(&adapter->tc); spin_unlock_irqrestore(&adapter->tmreg_lock, flags); mutex_unlock(&adapter->ptp_clk_mutex); *ts = ns_to_timespec64(ns); return 0; } /** * fec_ptp_settime * @ptp: the ptp clock structure * @ts: the timespec containing the new time for the cycle counter * * reset the timecounter to use a new base value instead of the kernel * wall timer value. */ static int fec_ptp_settime(struct ptp_clock_info *ptp, const struct timespec64 *ts) { struct fec_enet_private *fep = container_of(ptp, struct fec_enet_private, ptp_caps); u64 ns; unsigned long flags; u32 counter; mutex_lock(&fep->ptp_clk_mutex); /* Check the ptp clock */ if (!fep->ptp_clk_on) { mutex_unlock(&fep->ptp_clk_mutex); return -EINVAL; } ns = timespec64_to_ns(ts); /* Get the timer value based on timestamp. * Update the counter with the masked value. */ counter = ns & fep->cc.mask; spin_lock_irqsave(&fep->tmreg_lock, flags); writel(counter, fep->hwp + FEC_ATIME); timecounter_init(&fep->tc, &fep->cc, ns); spin_unlock_irqrestore(&fep->tmreg_lock, flags); mutex_unlock(&fep->ptp_clk_mutex); return 0; } /** * fec_ptp_enable * @ptp: the ptp clock structure * @rq: the requested feature to change * @on: whether to enable or disable the feature * */ static int fec_ptp_enable(struct ptp_clock_info *ptp, struct ptp_clock_request *rq, int on) { struct fec_enet_private *fep = container_of(ptp, struct fec_enet_private, ptp_caps); int ret = 0; if (rq->type == PTP_CLK_REQ_PPS) { ret = fec_ptp_enable_pps(fep, on); return ret; } return -EOPNOTSUPP; } int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr) { struct fec_enet_private *fep = netdev_priv(ndev); struct hwtstamp_config config; if (copy_from_user(&config, ifr->ifr_data, sizeof(config))) return -EFAULT; /* reserved for future extensions */ if (config.flags) return -EINVAL; switch (config.tx_type) { case HWTSTAMP_TX_OFF: fep->hwts_tx_en = 0; break; case HWTSTAMP_TX_ON: fep->hwts_tx_en = 1; break; default: return -ERANGE; } switch (config.rx_filter) { case HWTSTAMP_FILTER_NONE: if (fep->hwts_rx_en) fep->hwts_rx_en = 0; config.rx_filter = HWTSTAMP_FILTER_NONE; break; default: fep->hwts_rx_en = 1; config.rx_filter = HWTSTAMP_FILTER_ALL; break; } return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ? -EFAULT : 0; } int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr) { struct fec_enet_private *fep = netdev_priv(ndev); struct hwtstamp_config config; config.flags = 0; config.tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF; config.rx_filter = (fep->hwts_rx_en ? HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE); return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ? -EFAULT : 0; } /** * fec_time_keep - call timecounter_read every second to avoid timer overrun * because ENET just support 32bit counter, will timeout in 4s */ static void fec_time_keep(struct work_struct *work) { struct delayed_work *dwork = to_delayed_work(work); struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep); u64 ns; unsigned long flags; mutex_lock(&fep->ptp_clk_mutex); if (fep->ptp_clk_on) { spin_lock_irqsave(&fep->tmreg_lock, flags); ns = timecounter_read(&fep->tc); spin_unlock_irqrestore(&fep->tmreg_lock, flags); } mutex_unlock(&fep->ptp_clk_mutex); schedule_delayed_work(&fep->time_keep, HZ); } /* This function checks the pps event and reloads the timer compare counter. */ static irqreturn_t fec_pps_interrupt(int irq, void *dev_id) { struct net_device *ndev = dev_id; struct fec_enet_private *fep = netdev_priv(ndev); u32 val; u8 channel = fep->pps_channel; struct ptp_clock_event event; val = readl(fep->hwp + FEC_TCSR(channel)); if (val & FEC_T_TF_MASK) { /* Write the next next compare(not the next according the spec) * value to the register */ writel(fep->next_counter, fep->hwp + FEC_TCCR(channel)); do { writel(val, fep->hwp + FEC_TCSR(channel)); } while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK); /* Update the counter; */ fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask; event.type = PTP_CLOCK_PPS; ptp_clock_event(fep->ptp_clock, &event); return IRQ_HANDLED; } return IRQ_NONE; } /** * fec_ptp_init * @ndev: The FEC network adapter * * This function performs the required steps for enabling ptp * support. If ptp support has already been loaded it simply calls the * cyclecounter init routine and exits. */ void fec_ptp_init(struct platform_device *pdev, int irq_idx) { struct net_device *ndev = platform_get_drvdata(pdev); struct fec_enet_private *fep = netdev_priv(ndev); int irq; int ret; fep->ptp_caps.owner = THIS_MODULE; snprintf(fep->ptp_caps.name, 16, "fec ptp"); fep->ptp_caps.max_adj = 250000000; fep->ptp_caps.n_alarm = 0; fep->ptp_caps.n_ext_ts = 0; fep->ptp_caps.n_per_out = 0; fep->ptp_caps.n_pins = 0; fep->ptp_caps.pps = 1; fep->ptp_caps.adjfreq = fec_ptp_adjfreq; fep->ptp_caps.adjtime = fec_ptp_adjtime; fep->ptp_caps.gettime64 = fec_ptp_gettime; fep->ptp_caps.settime64 = fec_ptp_settime; fep->ptp_caps.enable = fec_ptp_enable; fep->cycle_speed = clk_get_rate(fep->clk_ptp); fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed; spin_lock_init(&fep->tmreg_lock); fec_ptp_start_cyclecounter(ndev); INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep); irq = platform_get_irq_byname(pdev, "pps"); if (irq < 0) irq = platform_get_irq(pdev, irq_idx); /* Failure to get an irq is not fatal, * only the PTP_CLOCK_PPS clock events should stop */ if (irq >= 0) { ret = devm_request_irq(&pdev->dev, irq, fec_pps_interrupt, 0, pdev->name, ndev); if (ret < 0) dev_warn(&pdev->dev, "request for pps irq failed(%d)\n", ret); } fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev); if (IS_ERR(fep->ptp_clock)) { fep->ptp_clock = NULL; pr_err("ptp_clock_register failed\n"); } schedule_delayed_work(&fep->time_keep, HZ); } void fec_ptp_stop(struct platform_device *pdev) { struct net_device *ndev = platform_get_drvdata(pdev); struct fec_enet_private *fep = netdev_priv(ndev); cancel_delayed_work_sync(&fep->time_keep); if (fep->ptp_clock) ptp_clock_unregister(fep->ptp_clock); }