2 * PTP 1588 clock using the IXP46X
4 * Copyright (C) 2010 OMICRON electronics GmbH
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include <linux/device.h>
21 #include <linux/err.h>
22 #include <linux/gpio.h>
23 #include <linux/init.h>
24 #include <linux/interrupt.h>
26 #include <linux/irq.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
30 #include <linux/ptp_clock_kernel.h>
31 #include <mach/ixp46x_ts.h>
33 #define DRIVER "ptp_ixp46x"
41 struct ixp46x_ts_regs *regs;
42 struct ptp_clock *ptp_clock;
43 struct ptp_clock_info caps;
48 DEFINE_SPINLOCK(register_lock);
51 * Register access functions
54 static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
59 lo = __raw_readl(®s->systime_lo);
60 hi = __raw_readl(®s->systime_hi);
62 ns = ((u64) hi) << 32;
64 ns <<= TICKS_NS_SHIFT;
69 static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
73 ns >>= TICKS_NS_SHIFT;
77 __raw_writel(lo, ®s->systime_lo);
78 __raw_writel(hi, ®s->systime_hi);
82 * Interrupt service routine
85 static irqreturn_t isr(int irq, void *priv)
87 struct ixp_clock *ixp_clock = priv;
88 struct ixp46x_ts_regs *regs = ixp_clock->regs;
89 struct ptp_clock_event event;
90 u32 ack = 0, lo, hi, val;
92 val = __raw_readl(®s->event);
96 if (ixp_clock->exts0_enabled) {
97 hi = __raw_readl(®s->asms_hi);
98 lo = __raw_readl(®s->asms_lo);
99 event.type = PTP_CLOCK_EXTTS;
101 event.timestamp = ((u64) hi) << 32;
102 event.timestamp |= lo;
103 event.timestamp <<= TICKS_NS_SHIFT;
104 ptp_clock_event(ixp_clock->ptp_clock, &event);
108 if (val & TSER_SNM) {
110 if (ixp_clock->exts1_enabled) {
111 hi = __raw_readl(®s->amms_hi);
112 lo = __raw_readl(®s->amms_lo);
113 event.type = PTP_CLOCK_EXTTS;
115 event.timestamp = ((u64) hi) << 32;
116 event.timestamp |= lo;
117 event.timestamp <<= TICKS_NS_SHIFT;
118 ptp_clock_event(ixp_clock->ptp_clock, &event);
123 ack |= TTIPEND; /* this bit seems to be always set */
126 __raw_writel(ack, ®s->event);
133 * PTP clock operations
136 static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
141 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
142 struct ixp46x_ts_regs *regs = ixp_clock->regs;
148 addend = DEFAULT_ADDEND;
151 diff = div_u64(adj, 1000000000ULL);
153 addend = neg_adj ? addend - diff : addend + diff;
155 __raw_writel(addend, ®s->addend);
160 static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
164 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
165 struct ixp46x_ts_regs *regs = ixp_clock->regs;
167 spin_lock_irqsave(®ister_lock, flags);
169 now = ixp_systime_read(regs);
171 ixp_systime_write(regs, now);
173 spin_unlock_irqrestore(®ister_lock, flags);
178 static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
183 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
184 struct ixp46x_ts_regs *regs = ixp_clock->regs;
186 spin_lock_irqsave(®ister_lock, flags);
188 ns = ixp_systime_read(regs);
190 spin_unlock_irqrestore(®ister_lock, flags);
192 ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
193 ts->tv_nsec = remainder;
197 static int ptp_ixp_settime(struct ptp_clock_info *ptp,
198 const struct timespec64 *ts)
202 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
203 struct ixp46x_ts_regs *regs = ixp_clock->regs;
205 ns = ts->tv_sec * 1000000000ULL;
208 spin_lock_irqsave(®ister_lock, flags);
210 ixp_systime_write(regs, ns);
212 spin_unlock_irqrestore(®ister_lock, flags);
217 static int ptp_ixp_enable(struct ptp_clock_info *ptp,
218 struct ptp_clock_request *rq, int on)
220 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
223 case PTP_CLK_REQ_EXTTS:
224 switch (rq->extts.index) {
226 ixp_clock->exts0_enabled = on ? 1 : 0;
229 ixp_clock->exts1_enabled = on ? 1 : 0;
242 static struct ptp_clock_info ptp_ixp_caps = {
243 .owner = THIS_MODULE,
244 .name = "IXP46X timer",
246 .n_ext_ts = N_EXT_TS,
249 .adjfreq = ptp_ixp_adjfreq,
250 .adjtime = ptp_ixp_adjtime,
251 .gettime64 = ptp_ixp_gettime,
252 .settime64 = ptp_ixp_settime,
253 .enable = ptp_ixp_enable,
256 /* module operations */
258 static struct ixp_clock ixp_clock;
260 static int setup_interrupt(int gpio)
265 err = gpio_request(gpio, "ixp4-ptp");
269 err = gpio_direction_input(gpio);
273 irq = gpio_to_irq(gpio);
278 if (irq_set_irq_type(irq, IRQF_TRIGGER_FALLING)) {
279 pr_err("cannot set trigger type for irq %d\n", irq);
283 if (request_irq(irq, isr, 0, DRIVER, &ixp_clock)) {
284 pr_err("request_irq failed for irq %d\n", irq);
291 static void __exit ptp_ixp_exit(void)
293 free_irq(MASTER_IRQ, &ixp_clock);
294 free_irq(SLAVE_IRQ, &ixp_clock);
295 ixp46x_phc_index = -1;
296 ptp_clock_unregister(ixp_clock.ptp_clock);
299 static int __init ptp_ixp_init(void)
301 if (!cpu_is_ixp46x())
305 (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
307 ixp_clock.caps = ptp_ixp_caps;
309 ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
311 if (IS_ERR(ixp_clock.ptp_clock))
312 return PTR_ERR(ixp_clock.ptp_clock);
314 ixp46x_phc_index = ptp_clock_index(ixp_clock.ptp_clock);
316 __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
317 __raw_writel(1, &ixp_clock.regs->trgt_lo);
318 __raw_writel(0, &ixp_clock.regs->trgt_hi);
319 __raw_writel(TTIPEND, &ixp_clock.regs->event);
321 if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
322 pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
325 if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
326 pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
332 free_irq(MASTER_IRQ, &ixp_clock);
334 ptp_clock_unregister(ixp_clock.ptp_clock);
338 module_init(ptp_ixp_init);
339 module_exit(ptp_ixp_exit);
341 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
342 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
343 MODULE_LICENSE("GPL");