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/module.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/err.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.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>
20
21 #include "ixp46x_ts.h"
22
23 #define DRIVER "ptp_ixp46x"
24 #define N_EXT_TS 2
25
26 struct ixp_clock {
27 struct ixp46x_ts_regs *regs;
28 struct ptp_clock *ptp_clock;
29 struct ptp_clock_info caps;
30 int exts0_enabled;
31 int exts1_enabled;
32 int slave_irq;
33 int master_irq;
34 };
35
36 static 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
ixp46x_ptp_find(struct ixp46x_ts_regs * __iomem * regs,int * phc_index)245 int ixp46x_ptp_find(struct ixp46x_ts_regs *__iomem *regs, int *phc_index)
246 {
247 *regs = ixp_clock.regs;
248 *phc_index = ptp_clock_index(ixp_clock.ptp_clock);
249
250 if (!ixp_clock.ptp_clock)
251 return -EPROBE_DEFER;
252
253 return 0;
254 }
255 EXPORT_SYMBOL_GPL(ixp46x_ptp_find);
256
257 /* Called from the registered devm action */
ptp_ixp_unregister_action(void * d)258 static void ptp_ixp_unregister_action(void *d)
259 {
260 struct ptp_clock *ptp_clock = d;
261
262 ptp_clock_unregister(ptp_clock);
263 ixp_clock.ptp_clock = NULL;
264 }
265
ptp_ixp_probe(struct platform_device * pdev)266 static int ptp_ixp_probe(struct platform_device *pdev)
267 {
268 struct device *dev = &pdev->dev;
269 int ret;
270
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 < 0 || ixp_clock.slave_irq < 0)
276 return -ENXIO;
277
278 ixp_clock.caps = ptp_ixp_caps;
279
280 ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
281
282 if (IS_ERR(ixp_clock.ptp_clock))
283 return PTR_ERR(ixp_clock.ptp_clock);
284
285 ret = devm_add_action_or_reset(dev, ptp_ixp_unregister_action,
286 ixp_clock.ptp_clock);
287 if (ret) {
288 dev_err(dev, "failed to install clock removal handler\n");
289 return ret;
290 }
291
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);
296
297 ret = devm_request_irq(dev, ixp_clock.master_irq, isr,
298 0, DRIVER, &ixp_clock);
299 if (ret)
300 return dev_err_probe(dev, ret,
301 "request_irq failed for irq %d\n",
302 ixp_clock.master_irq);
303
304 ret = devm_request_irq(dev, ixp_clock.slave_irq, isr,
305 0, DRIVER, &ixp_clock);
306 if (ret)
307 return dev_err_probe(dev, ret,
308 "request_irq failed for irq %d\n",
309 ixp_clock.slave_irq);
310
311 return 0;
312 }
313
314 static const struct of_device_id ptp_ixp_match[] = {
315 {
316 .compatible = "intel,ixp46x-ptp-timer",
317 },
318 { },
319 };
320
321 static struct platform_driver ptp_ixp_driver = {
322 .driver = {
323 .name = "ptp-ixp46x",
324 .of_match_table = ptp_ixp_match,
325 .suppress_bind_attrs = true,
326 },
327 .probe = ptp_ixp_probe,
328 };
329 module_platform_driver(ptp_ixp_driver);
330
331 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
332 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
333 MODULE_LICENSE("GPL");
334