/* * PTP 1588 clock using the IXP46X * * Copyright (C) 2010 OMICRON electronics GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/device.h> #include <linux/err.h> #include <linux/gpio.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/ptp_clock_kernel.h> #include <mach/ixp46x_ts.h> #define DRIVER "ptp_ixp46x" #define N_EXT_TS 2 #define MASTER_GPIO 8 #define MASTER_IRQ 25 #define SLAVE_GPIO 7 #define SLAVE_IRQ 24 struct ixp_clock { struct ixp46x_ts_regs *regs; struct ptp_clock *ptp_clock; struct ptp_clock_info caps; int exts0_enabled; int exts1_enabled; }; DEFINE_SPINLOCK(register_lock); /* * Register access functions */ static u64 ixp_systime_read(struct ixp46x_ts_regs *regs) { u64 ns; u32 lo, hi; lo = __raw_readl(®s->systime_lo); hi = __raw_readl(®s->systime_hi); ns = ((u64) hi) << 32; ns |= lo; ns <<= TICKS_NS_SHIFT; return ns; } static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns) { u32 hi, lo; ns >>= TICKS_NS_SHIFT; hi = ns >> 32; lo = ns & 0xffffffff; __raw_writel(lo, ®s->systime_lo); __raw_writel(hi, ®s->systime_hi); } /* * Interrupt service routine */ static irqreturn_t isr(int irq, void *priv) { struct ixp_clock *ixp_clock = priv; struct ixp46x_ts_regs *regs = ixp_clock->regs; struct ptp_clock_event event; u32 ack = 0, lo, hi, val; val = __raw_readl(®s->event); if (val & TSER_SNS) { ack |= TSER_SNS; if (ixp_clock->exts0_enabled) { hi = __raw_readl(®s->asms_hi); lo = __raw_readl(®s->asms_lo); event.type = PTP_CLOCK_EXTTS; event.index = 0; event.timestamp = ((u64) hi) << 32; event.timestamp |= lo; event.timestamp <<= TICKS_NS_SHIFT; ptp_clock_event(ixp_clock->ptp_clock, &event); } } if (val & TSER_SNM) { ack |= TSER_SNM; if (ixp_clock->exts1_enabled) { hi = __raw_readl(®s->amms_hi); lo = __raw_readl(®s->amms_lo); event.type = PTP_CLOCK_EXTTS; event.index = 1; event.timestamp = ((u64) hi) << 32; event.timestamp |= lo; event.timestamp <<= TICKS_NS_SHIFT; ptp_clock_event(ixp_clock->ptp_clock, &event); } } if (val & TTIPEND) ack |= TTIPEND; /* this bit seems to be always set */ if (ack) { __raw_writel(ack, ®s->event); return IRQ_HANDLED; } else return IRQ_NONE; } /* * PTP clock operations */ static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) { u64 adj; u32 diff, addend; int neg_adj = 0; struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps); struct ixp46x_ts_regs *regs = ixp_clock->regs; if (ppb < 0) { neg_adj = 1; ppb = -ppb; } addend = DEFAULT_ADDEND; adj = addend; adj *= ppb; diff = div_u64(adj, 1000000000ULL); addend = neg_adj ? addend - diff : addend + diff; __raw_writel(addend, ®s->addend); return 0; } static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta) { s64 now; unsigned long flags; struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps); struct ixp46x_ts_regs *regs = ixp_clock->regs; spin_lock_irqsave(®ister_lock, flags); now = ixp_systime_read(regs); now += delta; ixp_systime_write(regs, now); spin_unlock_irqrestore(®ister_lock, flags); return 0; } static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec *ts) { u64 ns; u32 remainder; unsigned long flags; struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps); struct ixp46x_ts_regs *regs = ixp_clock->regs; spin_lock_irqsave(®ister_lock, flags); ns = ixp_systime_read(regs); spin_unlock_irqrestore(®ister_lock, flags); ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder); ts->tv_nsec = remainder; return 0; } static int ptp_ixp_settime(struct ptp_clock_info *ptp, const struct timespec *ts) { u64 ns; unsigned long flags; struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps); struct ixp46x_ts_regs *regs = ixp_clock->regs; ns = ts->tv_sec * 1000000000ULL; ns += ts->tv_nsec; spin_lock_irqsave(®ister_lock, flags); ixp_systime_write(regs, ns); spin_unlock_irqrestore(®ister_lock, flags); return 0; } static int ptp_ixp_enable(struct ptp_clock_info *ptp, struct ptp_clock_request *rq, int on) { struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps); switch (rq->type) { case PTP_CLK_REQ_EXTTS: switch (rq->extts.index) { case 0: ixp_clock->exts0_enabled = on ? 1 : 0; break; case 1: ixp_clock->exts1_enabled = on ? 1 : 0; break; default: return -EINVAL; } return 0; default: break; } return -EOPNOTSUPP; } static struct ptp_clock_info ptp_ixp_caps = { .owner = THIS_MODULE, .name = "IXP46X timer", .max_adj = 66666655, .n_ext_ts = N_EXT_TS, .n_pins = 0, .pps = 0, .adjfreq = ptp_ixp_adjfreq, .adjtime = ptp_ixp_adjtime, .gettime = ptp_ixp_gettime, .settime = ptp_ixp_settime, .enable = ptp_ixp_enable, }; /* module operations */ static struct ixp_clock ixp_clock; static int setup_interrupt(int gpio) { int irq; int err; err = gpio_request(gpio, "ixp4-ptp"); if (err) return err; err = gpio_direction_input(gpio); if (err) return err; irq = gpio_to_irq(gpio); if (NO_IRQ == irq) return NO_IRQ; if (irq_set_irq_type(irq, IRQF_TRIGGER_FALLING)) { pr_err("cannot set trigger type for irq %d\n", irq); return NO_IRQ; } if (request_irq(irq, isr, 0, DRIVER, &ixp_clock)) { pr_err("request_irq failed for irq %d\n", irq); return NO_IRQ; } return irq; } static void __exit ptp_ixp_exit(void) { free_irq(MASTER_IRQ, &ixp_clock); free_irq(SLAVE_IRQ, &ixp_clock); ixp46x_phc_index = -1; ptp_clock_unregister(ixp_clock.ptp_clock); } static int __init ptp_ixp_init(void) { if (!cpu_is_ixp46x()) return -ENODEV; ixp_clock.regs = (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT; ixp_clock.caps = ptp_ixp_caps; ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL); if (IS_ERR(ixp_clock.ptp_clock)) return PTR_ERR(ixp_clock.ptp_clock); ixp46x_phc_index = ptp_clock_index(ixp_clock.ptp_clock); __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend); __raw_writel(1, &ixp_clock.regs->trgt_lo); __raw_writel(0, &ixp_clock.regs->trgt_hi); __raw_writel(TTIPEND, &ixp_clock.regs->event); if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) { pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO); goto no_master; } if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) { pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO); goto no_slave; } return 0; no_slave: free_irq(MASTER_IRQ, &ixp_clock); no_master: ptp_clock_unregister(ixp_clock.ptp_clock); return -ENODEV; } module_init(ptp_ixp_init); module_exit(ptp_ixp_exit); MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); MODULE_DESCRIPTION("PTP clock using the IXP46X timer"); MODULE_LICENSE("GPL");