1 /*
2 * PTP 1588 clock using the IXP46X
3 *
4 * Copyright (C) 2010 OMICRON electronics GmbH
5 *
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.
10 *
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.
15 *
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.
19 */
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>
25 #include <linux/io.h>
26 #include <linux/irq.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29
30 #include <linux/ptp_clock_kernel.h>
31 #include <mach/ixp46x_ts.h>
32
33 #define DRIVER "ptp_ixp46x"
34 #define N_EXT_TS 2
35 #define MASTER_GPIO 8
36 #define MASTER_IRQ 25
37 #define SLAVE_GPIO 7
38 #define SLAVE_IRQ 24
39
40 struct ixp_clock {
41 struct ixp46x_ts_regs *regs;
42 struct ptp_clock *ptp_clock;
43 struct ptp_clock_info caps;
44 int exts0_enabled;
45 int exts1_enabled;
46 };
47
48 DEFINE_SPINLOCK(register_lock);
49
50 /*
51 * Register access functions
52 */
53
ixp_systime_read(struct ixp46x_ts_regs * regs)54 static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
55 {
56 u64 ns;
57 u32 lo, hi;
58
59 lo = __raw_readl(®s->systime_lo);
60 hi = __raw_readl(®s->systime_hi);
61
62 ns = ((u64) hi) << 32;
63 ns |= lo;
64 ns <<= TICKS_NS_SHIFT;
65
66 return ns;
67 }
68
ixp_systime_write(struct ixp46x_ts_regs * regs,u64 ns)69 static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
70 {
71 u32 hi, lo;
72
73 ns >>= TICKS_NS_SHIFT;
74 hi = ns >> 32;
75 lo = ns & 0xffffffff;
76
77 __raw_writel(lo, ®s->systime_lo);
78 __raw_writel(hi, ®s->systime_hi);
79 }
80
81 /*
82 * Interrupt service routine
83 */
84
isr(int irq,void * priv)85 static irqreturn_t isr(int irq, void *priv)
86 {
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;
91
92 val = __raw_readl(®s->event);
93
94 if (val & TSER_SNS) {
95 ack |= TSER_SNS;
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;
100 event.index = 0;
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);
105 }
106 }
107
108 if (val & TSER_SNM) {
109 ack |= 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;
114 event.index = 1;
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);
119 }
120 }
121
122 if (val & TTIPEND)
123 ack |= TTIPEND; /* this bit seems to be always set */
124
125 if (ack) {
126 __raw_writel(ack, ®s->event);
127 return IRQ_HANDLED;
128 } else
129 return IRQ_NONE;
130 }
131
132 /*
133 * PTP clock operations
134 */
135
ptp_ixp_adjfreq(struct ptp_clock_info * ptp,s32 ppb)136 static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
137 {
138 u64 adj;
139 u32 diff, addend;
140 int neg_adj = 0;
141 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
142 struct ixp46x_ts_regs *regs = ixp_clock->regs;
143
144 if (ppb < 0) {
145 neg_adj = 1;
146 ppb = -ppb;
147 }
148 addend = DEFAULT_ADDEND;
149 adj = addend;
150 adj *= ppb;
151 diff = div_u64(adj, 1000000000ULL);
152
153 addend = neg_adj ? addend - diff : addend + diff;
154
155 __raw_writel(addend, ®s->addend);
156
157 return 0;
158 }
159
ptp_ixp_adjtime(struct ptp_clock_info * ptp,s64 delta)160 static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
161 {
162 s64 now;
163 unsigned long flags;
164 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
165 struct ixp46x_ts_regs *regs = ixp_clock->regs;
166
167 spin_lock_irqsave(®ister_lock, flags);
168
169 now = ixp_systime_read(regs);
170 now += delta;
171 ixp_systime_write(regs, now);
172
173 spin_unlock_irqrestore(®ister_lock, flags);
174
175 return 0;
176 }
177
ptp_ixp_gettime(struct ptp_clock_info * ptp,struct timespec64 * ts)178 static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
179 {
180 u64 ns;
181 unsigned long flags;
182 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
183 struct ixp46x_ts_regs *regs = ixp_clock->regs;
184
185 spin_lock_irqsave(®ister_lock, flags);
186
187 ns = ixp_systime_read(regs);
188
189 spin_unlock_irqrestore(®ister_lock, flags);
190
191 *ts = ns_to_timespec64(ns);
192 return 0;
193 }
194
ptp_ixp_settime(struct ptp_clock_info * ptp,const struct timespec64 * ts)195 static int ptp_ixp_settime(struct ptp_clock_info *ptp,
196 const struct timespec64 *ts)
197 {
198 u64 ns;
199 unsigned long flags;
200 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
201 struct ixp46x_ts_regs *regs = ixp_clock->regs;
202
203 ns = timespec64_to_ns(ts);
204
205 spin_lock_irqsave(®ister_lock, flags);
206
207 ixp_systime_write(regs, ns);
208
209 spin_unlock_irqrestore(®ister_lock, flags);
210
211 return 0;
212 }
213
ptp_ixp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * rq,int on)214 static int ptp_ixp_enable(struct ptp_clock_info *ptp,
215 struct ptp_clock_request *rq, int on)
216 {
217 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
218
219 switch (rq->type) {
220 case PTP_CLK_REQ_EXTTS:
221 switch (rq->extts.index) {
222 case 0:
223 ixp_clock->exts0_enabled = on ? 1 : 0;
224 break;
225 case 1:
226 ixp_clock->exts1_enabled = on ? 1 : 0;
227 break;
228 default:
229 return -EINVAL;
230 }
231 return 0;
232 default:
233 break;
234 }
235
236 return -EOPNOTSUPP;
237 }
238
239 static const struct ptp_clock_info ptp_ixp_caps = {
240 .owner = THIS_MODULE,
241 .name = "IXP46X timer",
242 .max_adj = 66666655,
243 .n_ext_ts = N_EXT_TS,
244 .n_pins = 0,
245 .pps = 0,
246 .adjfreq = ptp_ixp_adjfreq,
247 .adjtime = ptp_ixp_adjtime,
248 .gettime64 = ptp_ixp_gettime,
249 .settime64 = ptp_ixp_settime,
250 .enable = ptp_ixp_enable,
251 };
252
253 /* module operations */
254
255 static struct ixp_clock ixp_clock;
256
setup_interrupt(int gpio)257 static int setup_interrupt(int gpio)
258 {
259 int irq;
260 int err;
261
262 err = gpio_request(gpio, "ixp4-ptp");
263 if (err)
264 return err;
265
266 err = gpio_direction_input(gpio);
267 if (err)
268 return err;
269
270 irq = gpio_to_irq(gpio);
271 if (irq < 0)
272 return irq;
273
274 err = irq_set_irq_type(irq, IRQF_TRIGGER_FALLING);
275 if (err) {
276 pr_err("cannot set trigger type for irq %d\n", irq);
277 return err;
278 }
279
280 err = request_irq(irq, isr, 0, DRIVER, &ixp_clock);
281 if (err) {
282 pr_err("request_irq failed for irq %d\n", irq);
283 return err;
284 }
285
286 return irq;
287 }
288
ptp_ixp_exit(void)289 static void __exit ptp_ixp_exit(void)
290 {
291 free_irq(MASTER_IRQ, &ixp_clock);
292 free_irq(SLAVE_IRQ, &ixp_clock);
293 ixp46x_phc_index = -1;
294 ptp_clock_unregister(ixp_clock.ptp_clock);
295 }
296
ptp_ixp_init(void)297 static int __init ptp_ixp_init(void)
298 {
299 if (!cpu_is_ixp46x())
300 return -ENODEV;
301
302 ixp_clock.regs =
303 (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
304
305 ixp_clock.caps = ptp_ixp_caps;
306
307 ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
308
309 if (IS_ERR(ixp_clock.ptp_clock))
310 return PTR_ERR(ixp_clock.ptp_clock);
311
312 ixp46x_phc_index = ptp_clock_index(ixp_clock.ptp_clock);
313
314 __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
315 __raw_writel(1, &ixp_clock.regs->trgt_lo);
316 __raw_writel(0, &ixp_clock.regs->trgt_hi);
317 __raw_writel(TTIPEND, &ixp_clock.regs->event);
318
319 if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
320 pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
321 goto no_master;
322 }
323 if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
324 pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
325 goto no_slave;
326 }
327
328 return 0;
329 no_slave:
330 free_irq(MASTER_IRQ, &ixp_clock);
331 no_master:
332 ptp_clock_unregister(ixp_clock.ptp_clock);
333 return -ENODEV;
334 }
335
336 module_init(ptp_ixp_init);
337 module_exit(ptp_ixp_exit);
338
339 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
340 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
341 MODULE_LICENSE("GPL");
342