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
25struct 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
35static DEFINE_SPINLOCK(register_lock);
36
37/*
38 * Register access functions
39 */
40
41static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
42{
43 u64 ns;
44 u32 lo, hi;
45
46 lo = __raw_readl(addr: &regs->systime_lo);
47 hi = __raw_readl(addr: &regs->systime_hi);
48
49 ns = ((u64) hi) << 32;
50 ns |= lo;
51 ns <<= TICKS_NS_SHIFT;
52
53 return ns;
54}
55
56static 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(val: lo, addr: &regs->systime_lo);
65 __raw_writel(val: hi, addr: &regs->systime_hi);
66}
67
68/*
69 * Interrupt service routine
70 */
71
72static 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(addr: &regs->event);
80
81 if (val & TSER_SNS) {
82 ack |= TSER_SNS;
83 if (ixp_clock->exts0_enabled) {
84 hi = __raw_readl(addr: &regs->asms_hi);
85 lo = __raw_readl(addr: &regs->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(ptp: ixp_clock->ptp_clock, event: &event);
92 }
93 }
94
95 if (val & TSER_SNM) {
96 ack |= TSER_SNM;
97 if (ixp_clock->exts1_enabled) {
98 hi = __raw_readl(addr: &regs->amms_hi);
99 lo = __raw_readl(addr: &regs->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(ptp: ixp_clock->ptp_clock, event: &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(val: ack, addr: &regs->event);
114 return IRQ_HANDLED;
115 } else
116 return IRQ_NONE;
117}
118
119/*
120 * PTP clock operations
121 */
122
123static 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(val: addend, addr: &regs->addend);
132
133 return 0;
134}
135
136static 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(&register_lock, flags);
144
145 now = ixp_systime_read(regs);
146 now += delta;
147 ixp_systime_write(regs, ns: now);
148
149 spin_unlock_irqrestore(lock: &register_lock, flags);
150
151 return 0;
152}
153
154static 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(&register_lock, flags);
162
163 ns = ixp_systime_read(regs);
164
165 spin_unlock_irqrestore(lock: &register_lock, flags);
166
167 *ts = ns_to_timespec64(nsec: ns);
168 return 0;
169}
170
171static 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(&register_lock, flags);
182
183 ixp_systime_write(regs, ns);
184
185 spin_unlock_irqrestore(lock: &register_lock, flags);
186
187 return 0;
188}
189
190static 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
215static 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
231static struct ixp_clock ixp_clock;
232
233int ixp46x_ptp_find(struct ixp46x_ts_regs *__iomem *regs, int *phc_index)
234{
235 *regs = ixp_clock.regs;
236 *phc_index = ptp_clock_index(ptp: ixp_clock.ptp_clock);
237
238 if (!ixp_clock.ptp_clock)
239 return -EPROBE_DEFER;
240
241 return 0;
242}
243EXPORT_SYMBOL_GPL(ixp46x_ptp_find);
244
245/* Called from the registered devm action */
246static void ptp_ixp_unregister_action(void *d)
247{
248 struct ptp_clock *ptp_clock = d;
249
250 ptp_clock_unregister(ptp: ptp_clock);
251 ixp_clock.ptp_clock = NULL;
252}
253
254static 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, index: 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(ptr: 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(info: &ixp_clock.caps, NULL);
269
270 if (IS_ERR(ptr: ixp_clock.ptp_clock))
271 return PTR_ERR(ptr: 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, addr: &ixp_clock.regs->addend);
281 __raw_writel(val: 1, addr: &ixp_clock.regs->trgt_lo);
282 __raw_writel(val: 0, addr: &ixp_clock.regs->trgt_hi);
283 __raw_writel(TTIPEND, addr: &ixp_clock.regs->event);
284
285 ret = devm_request_irq(dev, irq: ixp_clock.master_irq, handler: isr,
286 irqflags: 0, DRIVER, dev_id: &ixp_clock);
287 if (ret)
288 return dev_err_probe(dev, err: ret,
289 fmt: "request_irq failed for irq %d\n",
290 ixp_clock.master_irq);
291
292 ret = devm_request_irq(dev, irq: ixp_clock.slave_irq, handler: isr,
293 irqflags: 0, DRIVER, dev_id: &ixp_clock);
294 if (ret)
295 return dev_err_probe(dev, err: ret,
296 fmt: "request_irq failed for irq %d\n",
297 ixp_clock.slave_irq);
298
299 return 0;
300}
301
302static const struct of_device_id ptp_ixp_match[] = {
303 {
304 .compatible = "intel,ixp46x-ptp-timer",
305 },
306 { },
307};
308
309static 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};
317module_platform_driver(ptp_ixp_driver);
318
319MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
320MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
321MODULE_LICENSE("GPL");
322

source code of linux/drivers/net/ethernet/xscale/ptp_ixp46x.c