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
20 #include "ixp46x_ts.h"
21
22 #define DRIVER "ptp_ixp46x"
23 #define N_EXT_TS 2
24
25 struct ixp_clock {
26 struct ixp46x_ts_regs *regs;
27 struct ptp_clock *ptp_clock;
28 struct ptp_clock_info caps;
29 int exts0_enabled;
30 int exts1_enabled;
31 int slave_irq;
32 int master_irq;
33 };
34
35 static DEFINE_SPINLOCK(register_lock);
36
37 /*
38 * Register access functions
39 */
40
ixp_systime_read(struct ixp46x_ts_regs * regs)41 static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
42 {
43 u64 ns;
44 u32 lo, hi;
45
46 lo = __raw_readl(®s->systime_lo);
47 hi = __raw_readl(®s->systime_hi);
48
49 ns = ((u64) hi) << 32;
50 ns |= lo;
51 ns <<= TICKS_NS_SHIFT;
52
53 return ns;
54 }
55
ixp_systime_write(struct ixp46x_ts_regs * regs,u64 ns)56 static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
57 {
58 u32 hi, lo;
59
60 ns >>= TICKS_NS_SHIFT;
61 hi = ns >> 32;
62 lo = ns & 0xffffffff;
63
64 __raw_writel(lo, ®s->systime_lo);
65 __raw_writel(hi, ®s->systime_hi);
66 }
67
68 /*
69 * Interrupt service routine
70 */
71
isr(int irq,void * priv)72 static irqreturn_t isr(int irq, void *priv)
73 {
74 struct ixp_clock *ixp_clock = priv;
75 struct ixp46x_ts_regs *regs = ixp_clock->regs;
76 struct ptp_clock_event event;
77 u32 ack = 0, lo, hi, val;
78
79 val = __raw_readl(®s->event);
80
81 if (val & TSER_SNS) {
82 ack |= TSER_SNS;
83 if (ixp_clock->exts0_enabled) {
84 hi = __raw_readl(®s->asms_hi);
85 lo = __raw_readl(®s->asms_lo);
86 event.type = PTP_CLOCK_EXTTS;
87 event.index = 0;
88 event.timestamp = ((u64) hi) << 32;
89 event.timestamp |= lo;
90 event.timestamp <<= TICKS_NS_SHIFT;
91 ptp_clock_event(ixp_clock->ptp_clock, &event);
92 }
93 }
94
95 if (val & TSER_SNM) {
96 ack |= TSER_SNM;
97 if (ixp_clock->exts1_enabled) {
98 hi = __raw_readl(®s->amms_hi);
99 lo = __raw_readl(®s->amms_lo);
100 event.type = PTP_CLOCK_EXTTS;
101 event.index = 1;
102 event.timestamp = ((u64) hi) << 32;
103 event.timestamp |= lo;
104 event.timestamp <<= TICKS_NS_SHIFT;
105 ptp_clock_event(ixp_clock->ptp_clock, &event);
106 }
107 }
108
109 if (val & TTIPEND)
110 ack |= TTIPEND; /* this bit seems to be always set */
111
112 if (ack) {
113 __raw_writel(ack, ®s->event);
114 return IRQ_HANDLED;
115 } else
116 return IRQ_NONE;
117 }
118
119 /*
120 * PTP clock operations
121 */
122
ptp_ixp_adjfine(struct ptp_clock_info * ptp,long scaled_ppm)123 static int ptp_ixp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
124 {
125 u32 addend;
126 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
127 struct ixp46x_ts_regs *regs = ixp_clock->regs;
128
129 addend = adjust_by_scaled_ppm(DEFAULT_ADDEND, scaled_ppm);
130
131 __raw_writel(addend, ®s->addend);
132
133 return 0;
134 }
135
ptp_ixp_adjtime(struct ptp_clock_info * ptp,s64 delta)136 static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
137 {
138 s64 now;
139 unsigned long flags;
140 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
141 struct ixp46x_ts_regs *regs = ixp_clock->regs;
142
143 spin_lock_irqsave(®ister_lock, flags);
144
145 now = ixp_systime_read(regs);
146 now += delta;
147 ixp_systime_write(regs, now);
148
149 spin_unlock_irqrestore(®ister_lock, flags);
150
151 return 0;
152 }
153
ptp_ixp_gettime(struct ptp_clock_info * ptp,struct timespec64 * ts)154 static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
155 {
156 u64 ns;
157 unsigned long flags;
158 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
159 struct ixp46x_ts_regs *regs = ixp_clock->regs;
160
161 spin_lock_irqsave(®ister_lock, flags);
162
163 ns = ixp_systime_read(regs);
164
165 spin_unlock_irqrestore(®ister_lock, flags);
166
167 *ts = ns_to_timespec64(ns);
168 return 0;
169 }
170
ptp_ixp_settime(struct ptp_clock_info * ptp,const struct timespec64 * ts)171 static int ptp_ixp_settime(struct ptp_clock_info *ptp,
172 const struct timespec64 *ts)
173 {
174 u64 ns;
175 unsigned long flags;
176 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
177 struct ixp46x_ts_regs *regs = ixp_clock->regs;
178
179 ns = timespec64_to_ns(ts);
180
181 spin_lock_irqsave(®ister_lock, flags);
182
183 ixp_systime_write(regs, ns);
184
185 spin_unlock_irqrestore(®ister_lock, flags);
186
187 return 0;
188 }
189
ptp_ixp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * rq,int on)190 static int ptp_ixp_enable(struct ptp_clock_info *ptp,
191 struct ptp_clock_request *rq, int on)
192 {
193 struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
194
195 switch (rq->type) {
196 case PTP_CLK_REQ_EXTTS:
197 switch (rq->extts.index) {
198 case 0:
199 ixp_clock->exts0_enabled = on ? 1 : 0;
200 break;
201 case 1:
202 ixp_clock->exts1_enabled = on ? 1 : 0;
203 break;
204 default:
205 return -EINVAL;
206 }
207 return 0;
208 default:
209 break;
210 }
211
212 return -EOPNOTSUPP;
213 }
214
215 static const struct ptp_clock_info ptp_ixp_caps = {
216 .owner = THIS_MODULE,
217 .name = "IXP46X timer",
218 .max_adj = 66666655,
219 .n_ext_ts = N_EXT_TS,
220 .n_pins = 0,
221 .pps = 0,
222 .adjfine = ptp_ixp_adjfine,
223 .adjtime = ptp_ixp_adjtime,
224 .gettime64 = ptp_ixp_gettime,
225 .settime64 = ptp_ixp_settime,
226 .enable = ptp_ixp_enable,
227 };
228
229 /* module operations */
230
231 static struct ixp_clock ixp_clock;
232
ixp46x_ptp_find(struct ixp46x_ts_regs * __iomem * regs,int * phc_index)233 int ixp46x_ptp_find(struct ixp46x_ts_regs *__iomem *regs, int *phc_index)
234 {
235 *regs = ixp_clock.regs;
236 *phc_index = ptp_clock_index(ixp_clock.ptp_clock);
237
238 if (!ixp_clock.ptp_clock)
239 return -EPROBE_DEFER;
240
241 return 0;
242 }
243 EXPORT_SYMBOL_GPL(ixp46x_ptp_find);
244
245 /* Called from the registered devm action */
ptp_ixp_unregister_action(void * d)246 static void ptp_ixp_unregister_action(void *d)
247 {
248 struct ptp_clock *ptp_clock = d;
249
250 ptp_clock_unregister(ptp_clock);
251 ixp_clock.ptp_clock = NULL;
252 }
253
ptp_ixp_probe(struct platform_device * pdev)254 static int ptp_ixp_probe(struct platform_device *pdev)
255 {
256 struct device *dev = &pdev->dev;
257 int ret;
258
259 ixp_clock.regs = devm_platform_ioremap_resource(pdev, 0);
260 ixp_clock.master_irq = platform_get_irq(pdev, 0);
261 ixp_clock.slave_irq = platform_get_irq(pdev, 1);
262 if (IS_ERR(ixp_clock.regs) ||
263 ixp_clock.master_irq < 0 || ixp_clock.slave_irq < 0)
264 return -ENXIO;
265
266 ixp_clock.caps = ptp_ixp_caps;
267
268 ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
269
270 if (IS_ERR(ixp_clock.ptp_clock))
271 return PTR_ERR(ixp_clock.ptp_clock);
272
273 ret = devm_add_action_or_reset(dev, ptp_ixp_unregister_action,
274 ixp_clock.ptp_clock);
275 if (ret) {
276 dev_err(dev, "failed to install clock removal handler\n");
277 return ret;
278 }
279
280 __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
281 __raw_writel(1, &ixp_clock.regs->trgt_lo);
282 __raw_writel(0, &ixp_clock.regs->trgt_hi);
283 __raw_writel(TTIPEND, &ixp_clock.regs->event);
284
285 ret = devm_request_irq(dev, ixp_clock.master_irq, isr,
286 0, DRIVER, &ixp_clock);
287 if (ret)
288 return dev_err_probe(dev, ret,
289 "request_irq failed for irq %d\n",
290 ixp_clock.master_irq);
291
292 ret = devm_request_irq(dev, ixp_clock.slave_irq, isr,
293 0, DRIVER, &ixp_clock);
294 if (ret)
295 return dev_err_probe(dev, ret,
296 "request_irq failed for irq %d\n",
297 ixp_clock.slave_irq);
298
299 return 0;
300 }
301
302 static const struct of_device_id ptp_ixp_match[] = {
303 {
304 .compatible = "intel,ixp46x-ptp-timer",
305 },
306 { },
307 };
308
309 static struct platform_driver ptp_ixp_driver = {
310 .driver = {
311 .name = "ptp-ixp46x",
312 .of_match_table = ptp_ixp_match,
313 .suppress_bind_attrs = true,
314 },
315 .probe = ptp_ixp_probe,
316 };
317 module_platform_driver(ptp_ixp_driver);
318
319 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
320 MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
321 MODULE_LICENSE("GPL");
322