1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * PTP 1588 clock using the IXP46X
5 * Copyright (C) 2010 OMICRON electronics GmbH
7 #include <linux/device.h>
8 #include <linux/module.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/err.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
14 #include <linux/irq.h>
15 #include <linux/kernel.h>
16 #include <linux/ptp_clock_kernel.h>
17 #include <linux/platform_device.h>
18 #include <linux/soc/ixp4xx/cpu.h>
19 #include <mach/ixp4xx-regs.h>
21 #include "ixp46x_ts.h"
23 #define DRIVER "ptp_ixp46x"
27 struct ixp46x_ts_regs *regs;
28 struct ptp_clock *ptp_clock;
29 struct ptp_clock_info caps;
36 static DEFINE_SPINLOCK(register_lock);
39 * Register access functions
42 static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
47 lo = __raw_readl(®s->systime_lo);
48 hi = __raw_readl(®s->systime_hi);
50 ns = ((u64) hi) << 32;
52 ns <<= TICKS_NS_SHIFT;
57 static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
61 ns >>= TICKS_NS_SHIFT;
65 __raw_writel(lo, ®s->systime_lo);
66 __raw_writel(hi, ®s->systime_hi);
70 * Interrupt service routine
73 static irqreturn_t isr(int irq, void *priv)
75 struct ixp_clock *ixp_clock = priv;
76 struct ixp46x_ts_regs *regs = ixp_clock->regs;
77 struct ptp_clock_event event;
78 u32 ack = 0, lo, hi, val;
80 val = __raw_readl(®s->event);
84 if (ixp_clock->exts0_enabled) {
85 hi = __raw_readl(®s->asms_hi);
86 lo = __raw_readl(®s->asms_lo);
87 event.type = PTP_CLOCK_EXTTS;
89 event.timestamp = ((u64) hi) << 32;
90 event.timestamp |= lo;
91 event.timestamp <<= TICKS_NS_SHIFT;
92 ptp_clock_event(ixp_clock->ptp_clock, &event);
98 if (ixp_clock->exts1_enabled) {
99 hi = __raw_readl(®s->amms_hi);
100 lo = __raw_readl(®s->amms_lo);
101 event.type = PTP_CLOCK_EXTTS;
103 event.timestamp = ((u64) hi) << 32;
104 event.timestamp |= lo;
105 event.timestamp <<= TICKS_NS_SHIFT;
106 ptp_clock_event(ixp_clock->ptp_clock, &event);
111 ack |= TTIPEND; /* this bit seems to be always set */
114 __raw_writel(ack, ®s->event);
121 * PTP clock operations
124 static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
129 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
130 struct ixp46x_ts_regs *regs = ixp_clock->regs;
136 addend = DEFAULT_ADDEND;
139 diff = div_u64(adj, 1000000000ULL);
141 addend = neg_adj ? addend - diff : addend + diff;
143 __raw_writel(addend, ®s->addend);
148 static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
152 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
153 struct ixp46x_ts_regs *regs = ixp_clock->regs;
155 spin_lock_irqsave(®ister_lock, flags);
157 now = ixp_systime_read(regs);
159 ixp_systime_write(regs, now);
161 spin_unlock_irqrestore(®ister_lock, flags);
166 static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
170 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
171 struct ixp46x_ts_regs *regs = ixp_clock->regs;
173 spin_lock_irqsave(®ister_lock, flags);
175 ns = ixp_systime_read(regs);
177 spin_unlock_irqrestore(®ister_lock, flags);
179 *ts = ns_to_timespec64(ns);
183 static int ptp_ixp_settime(struct ptp_clock_info *ptp,
184 const struct timespec64 *ts)
188 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
189 struct ixp46x_ts_regs *regs = ixp_clock->regs;
191 ns = timespec64_to_ns(ts);
193 spin_lock_irqsave(®ister_lock, flags);
195 ixp_systime_write(regs, ns);
197 spin_unlock_irqrestore(®ister_lock, flags);
202 static int ptp_ixp_enable(struct ptp_clock_info *ptp,
203 struct ptp_clock_request *rq, int on)
205 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
208 case PTP_CLK_REQ_EXTTS:
209 switch (rq->extts.index) {
211 ixp_clock->exts0_enabled = on ? 1 : 0;
214 ixp_clock->exts1_enabled = on ? 1 : 0;
227 static const struct ptp_clock_info ptp_ixp_caps = {
228 .owner = THIS_MODULE,
229 .name = "IXP46X timer",
231 .n_ext_ts = N_EXT_TS,
234 .adjfreq = ptp_ixp_adjfreq,
235 .adjtime = ptp_ixp_adjtime,
236 .gettime64 = ptp_ixp_gettime,
237 .settime64 = ptp_ixp_settime,
238 .enable = ptp_ixp_enable,
241 /* module operations */
243 static struct ixp_clock ixp_clock;
245 int ixp46x_ptp_find(struct ixp46x_ts_regs *__iomem *regs, int *phc_index)
247 *regs = ixp_clock.regs;
248 *phc_index = ptp_clock_index(ixp_clock.ptp_clock);
250 if (!ixp_clock.ptp_clock)
251 return -EPROBE_DEFER;
255 EXPORT_SYMBOL_GPL(ixp46x_ptp_find);
257 /* Called from the registered devm action */
258 static void ptp_ixp_unregister_action(void *d)
260 struct ptp_clock *ptp_clock = d;
262 ptp_clock_unregister(ptp_clock);
263 ixp_clock.ptp_clock = NULL;
266 static int ptp_ixp_probe(struct platform_device *pdev)
268 struct device *dev = &pdev->dev;
271 ixp_clock.regs = devm_platform_ioremap_resource(pdev, 0);
272 ixp_clock.master_irq = platform_get_irq(pdev, 0);
273 ixp_clock.slave_irq = platform_get_irq(pdev, 1);
274 if (IS_ERR(ixp_clock.regs) ||
275 !ixp_clock.master_irq || !ixp_clock.slave_irq)
278 ixp_clock.caps = ptp_ixp_caps;
280 ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
282 if (IS_ERR(ixp_clock.ptp_clock))
283 return PTR_ERR(ixp_clock.ptp_clock);
285 ret = devm_add_action_or_reset(dev, ptp_ixp_unregister_action,
286 ixp_clock.ptp_clock);
288 dev_err(dev, "failed to install clock removal handler\n");
292 __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
293 __raw_writel(1, &ixp_clock.regs->trgt_lo);
294 __raw_writel(0, &ixp_clock.regs->trgt_hi);
295 __raw_writel(TTIPEND, &ixp_clock.regs->event);
297 ret = devm_request_irq(dev, ixp_clock.master_irq, isr,
298 0, DRIVER, &ixp_clock);
300 return dev_err_probe(dev, ret,
301 "request_irq failed for irq %d\n",
302 ixp_clock.master_irq);
304 ret = devm_request_irq(dev, ixp_clock.slave_irq, isr,
305 0, DRIVER, &ixp_clock);
307 return dev_err_probe(dev, ret,
308 "request_irq failed for irq %d\n",
309 ixp_clock.slave_irq);
314 static const struct of_device_id ptp_ixp_match[] = {
316 .compatible = "intel,ixp46x-ptp-timer",
321 static struct platform_driver ptp_ixp_driver = {
323 .name = "ptp-ixp46x",
324 .of_match_table = ptp_ixp_match,
325 .suppress_bind_attrs = true,
327 .probe = ptp_ixp_probe,
329 module_platform_driver(ptp_ixp_driver);
331 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
332 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
333 MODULE_LICENSE("GPL");