1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * PTP 1588 clock using the IXP46X
4 *
5 * Copyright (C) 2010 OMICRON electronics GmbH
6 */
7 #include <linux/device.h>
8 #include <linux/err.h>
9 #include <linux/gpio.h>
10 #include <linux/init.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/irq.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16
17 #include <linux/ptp_clock_kernel.h>
18
19 #include "ixp46x_ts.h"
20
21 #define DRIVER "ptp_ixp46x"
22 #define N_EXT_TS 2
23 #define MASTER_GPIO 8
24 #define MASTER_IRQ 25
25 #define SLAVE_GPIO 7
26 #define SLAVE_IRQ 24
27
28 struct ixp_clock {
29 struct ixp46x_ts_regs *regs;
30 struct ptp_clock *ptp_clock;
31 struct ptp_clock_info caps;
32 int exts0_enabled;
33 int exts1_enabled;
34 };
35
36 DEFINE_SPINLOCK(register_lock);
37
38 /*
39 * Register access functions
40 */
41
ixp_systime_read(struct ixp46x_ts_regs * regs)42 static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
43 {
44 u64 ns;
45 u32 lo, hi;
46
47 lo = __raw_readl(®s->systime_lo);
48 hi = __raw_readl(®s->systime_hi);
49
50 ns = ((u64) hi) << 32;
51 ns |= lo;
52 ns <<= TICKS_NS_SHIFT;
53
54 return ns;
55 }
56
ixp_systime_write(struct ixp46x_ts_regs * regs,u64 ns)57 static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
58 {
59 u32 hi, lo;
60
61 ns >>= TICKS_NS_SHIFT;
62 hi = ns >> 32;
63 lo = ns & 0xffffffff;
64
65 __raw_writel(lo, ®s->systime_lo);
66 __raw_writel(hi, ®s->systime_hi);
67 }
68
69 /*
70 * Interrupt service routine
71 */
72
isr(int irq,void * priv)73 static irqreturn_t isr(int irq, void *priv)
74 {
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;
79
80 val = __raw_readl(®s->event);
81
82 if (val & TSER_SNS) {
83 ack |= TSER_SNS;
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;
88 event.index = 0;
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);
93 }
94 }
95
96 if (val & TSER_SNM) {
97 ack |= TSER_SNM;
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;
102 event.index = 1;
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);
107 }
108 }
109
110 if (val & TTIPEND)
111 ack |= TTIPEND; /* this bit seems to be always set */
112
113 if (ack) {
114 __raw_writel(ack, ®s->event);
115 return IRQ_HANDLED;
116 } else
117 return IRQ_NONE;
118 }
119
120 /*
121 * PTP clock operations
122 */
123
ptp_ixp_adjfreq(struct ptp_clock_info * ptp,s32 ppb)124 static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
125 {
126 u64 adj;
127 u32 diff, addend;
128 int neg_adj = 0;
129 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
130 struct ixp46x_ts_regs *regs = ixp_clock->regs;
131
132 if (ppb < 0) {
133 neg_adj = 1;
134 ppb = -ppb;
135 }
136 addend = DEFAULT_ADDEND;
137 adj = addend;
138 adj *= ppb;
139 diff = div_u64(adj, 1000000000ULL);
140
141 addend = neg_adj ? addend - diff : addend + diff;
142
143 __raw_writel(addend, ®s->addend);
144
145 return 0;
146 }
147
ptp_ixp_adjtime(struct ptp_clock_info * ptp,s64 delta)148 static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
149 {
150 s64 now;
151 unsigned long flags;
152 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
153 struct ixp46x_ts_regs *regs = ixp_clock->regs;
154
155 spin_lock_irqsave(®ister_lock, flags);
156
157 now = ixp_systime_read(regs);
158 now += delta;
159 ixp_systime_write(regs, now);
160
161 spin_unlock_irqrestore(®ister_lock, flags);
162
163 return 0;
164 }
165
ptp_ixp_gettime(struct ptp_clock_info * ptp,struct timespec64 * ts)166 static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
167 {
168 u64 ns;
169 unsigned long flags;
170 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
171 struct ixp46x_ts_regs *regs = ixp_clock->regs;
172
173 spin_lock_irqsave(®ister_lock, flags);
174
175 ns = ixp_systime_read(regs);
176
177 spin_unlock_irqrestore(®ister_lock, flags);
178
179 *ts = ns_to_timespec64(ns);
180 return 0;
181 }
182
ptp_ixp_settime(struct ptp_clock_info * ptp,const struct timespec64 * ts)183 static int ptp_ixp_settime(struct ptp_clock_info *ptp,
184 const struct timespec64 *ts)
185 {
186 u64 ns;
187 unsigned long flags;
188 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
189 struct ixp46x_ts_regs *regs = ixp_clock->regs;
190
191 ns = timespec64_to_ns(ts);
192
193 spin_lock_irqsave(®ister_lock, flags);
194
195 ixp_systime_write(regs, ns);
196
197 spin_unlock_irqrestore(®ister_lock, flags);
198
199 return 0;
200 }
201
ptp_ixp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * rq,int on)202 static int ptp_ixp_enable(struct ptp_clock_info *ptp,
203 struct ptp_clock_request *rq, int on)
204 {
205 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
206
207 switch (rq->type) {
208 case PTP_CLK_REQ_EXTTS:
209 switch (rq->extts.index) {
210 case 0:
211 ixp_clock->exts0_enabled = on ? 1 : 0;
212 break;
213 case 1:
214 ixp_clock->exts1_enabled = on ? 1 : 0;
215 break;
216 default:
217 return -EINVAL;
218 }
219 return 0;
220 default:
221 break;
222 }
223
224 return -EOPNOTSUPP;
225 }
226
227 static const struct ptp_clock_info ptp_ixp_caps = {
228 .owner = THIS_MODULE,
229 .name = "IXP46X timer",
230 .max_adj = 66666655,
231 .n_ext_ts = N_EXT_TS,
232 .n_pins = 0,
233 .pps = 0,
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,
239 };
240
241 /* module operations */
242
243 static struct ixp_clock ixp_clock;
244
setup_interrupt(int gpio)245 static int setup_interrupt(int gpio)
246 {
247 int irq;
248 int err;
249
250 err = gpio_request(gpio, "ixp4-ptp");
251 if (err)
252 return err;
253
254 err = gpio_direction_input(gpio);
255 if (err)
256 return err;
257
258 irq = gpio_to_irq(gpio);
259 if (irq < 0)
260 return irq;
261
262 err = irq_set_irq_type(irq, IRQF_TRIGGER_FALLING);
263 if (err) {
264 pr_err("cannot set trigger type for irq %d\n", irq);
265 return err;
266 }
267
268 err = request_irq(irq, isr, 0, DRIVER, &ixp_clock);
269 if (err) {
270 pr_err("request_irq failed for irq %d\n", irq);
271 return err;
272 }
273
274 return irq;
275 }
276
ptp_ixp_exit(void)277 static void __exit ptp_ixp_exit(void)
278 {
279 free_irq(MASTER_IRQ, &ixp_clock);
280 free_irq(SLAVE_IRQ, &ixp_clock);
281 ixp46x_phc_index = -1;
282 ptp_clock_unregister(ixp_clock.ptp_clock);
283 }
284
ptp_ixp_init(void)285 static int __init ptp_ixp_init(void)
286 {
287 if (!cpu_is_ixp46x())
288 return -ENODEV;
289
290 ixp_clock.regs =
291 (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
292
293 ixp_clock.caps = ptp_ixp_caps;
294
295 ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
296
297 if (IS_ERR(ixp_clock.ptp_clock))
298 return PTR_ERR(ixp_clock.ptp_clock);
299
300 ixp46x_phc_index = ptp_clock_index(ixp_clock.ptp_clock);
301
302 __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
303 __raw_writel(1, &ixp_clock.regs->trgt_lo);
304 __raw_writel(0, &ixp_clock.regs->trgt_hi);
305 __raw_writel(TTIPEND, &ixp_clock.regs->event);
306
307 if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
308 pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
309 goto no_master;
310 }
311 if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
312 pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
313 goto no_slave;
314 }
315
316 return 0;
317 no_slave:
318 free_irq(MASTER_IRQ, &ixp_clock);
319 no_master:
320 ptp_clock_unregister(ixp_clock.ptp_clock);
321 return -ENODEV;
322 }
323
324 module_init(ptp_ixp_init);
325 module_exit(ptp_ixp_exit);
326
327 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
328 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
329 MODULE_LICENSE("GPL");
330