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1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | // Copyright 2017 Broadcom | |
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3 | |
4 | #include <linux/err.h> | |
5 | #include <linux/io.h> | |
6 | #include <linux/module.h> | |
ac316725 | 7 | #include <linux/mod_devicetable.h> |
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8 | #include <linux/platform_device.h> |
9 | #include <linux/ptp_clock_kernel.h> | |
10 | #include <linux/types.h> | |
11 | ||
12 | #define DTE_NCO_LOW_TIME_REG 0x00 | |
13 | #define DTE_NCO_TIME_REG 0x04 | |
14 | #define DTE_NCO_OVERFLOW_REG 0x08 | |
15 | #define DTE_NCO_INC_REG 0x0c | |
16 | ||
17 | #define DTE_NCO_SUM2_MASK 0xffffffff | |
18 | #define DTE_NCO_SUM2_SHIFT 4ULL | |
19 | ||
20 | #define DTE_NCO_SUM3_MASK 0xff | |
21 | #define DTE_NCO_SUM3_SHIFT 36ULL | |
22 | #define DTE_NCO_SUM3_WR_SHIFT 8 | |
23 | ||
24 | #define DTE_NCO_TS_WRAP_MASK 0xfff | |
25 | #define DTE_NCO_TS_WRAP_LSHIFT 32 | |
26 | ||
27 | #define DTE_NCO_INC_DEFAULT 0x80000000 | |
28 | #define DTE_NUM_REGS_TO_RESTORE 4 | |
29 | ||
30 | /* Full wrap around is 44bits in ns (~4.887 hrs) */ | |
31 | #define DTE_WRAP_AROUND_NSEC_SHIFT 44 | |
32 | ||
33 | /* 44 bits NCO */ | |
3d05035e | 34 | #define DTE_NCO_MAX_NS 0xFFFFFFFFFFFLL |
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35 | |
36 | /* 125MHz with 3.29 reg cfg */ | |
37 | #define DTE_PPB_ADJ(ppb) (u32)(div64_u64((((u64)abs(ppb) * BIT(28)) +\ | |
38 | 62500000ULL), 125000000ULL)) | |
39 | ||
40 | /* ptp dte priv structure */ | |
41 | struct ptp_dte { | |
42 | void __iomem *regs; | |
43 | struct ptp_clock *ptp_clk; | |
44 | struct ptp_clock_info caps; | |
45 | struct device *dev; | |
46 | u32 ts_ovf_last; | |
47 | u32 ts_wrap_cnt; | |
48 | spinlock_t lock; | |
49 | u32 reg_val[DTE_NUM_REGS_TO_RESTORE]; | |
50 | }; | |
51 | ||
52 | static void dte_write_nco(void __iomem *regs, s64 ns) | |
53 | { | |
54 | u32 sum2, sum3; | |
55 | ||
56 | sum2 = (u32)((ns >> DTE_NCO_SUM2_SHIFT) & DTE_NCO_SUM2_MASK); | |
57 | /* compensate for ignoring sum1 */ | |
58 | if (sum2 != DTE_NCO_SUM2_MASK) | |
59 | sum2++; | |
60 | ||
61 | /* to write sum3, bits [15:8] needs to be written */ | |
62 | sum3 = (u32)(((ns >> DTE_NCO_SUM3_SHIFT) & DTE_NCO_SUM3_MASK) << | |
63 | DTE_NCO_SUM3_WR_SHIFT); | |
64 | ||
65 | writel(0, (regs + DTE_NCO_LOW_TIME_REG)); | |
66 | writel(sum2, (regs + DTE_NCO_TIME_REG)); | |
67 | writel(sum3, (regs + DTE_NCO_OVERFLOW_REG)); | |
68 | } | |
69 | ||
70 | static s64 dte_read_nco(void __iomem *regs) | |
71 | { | |
72 | u32 sum2, sum3; | |
73 | s64 ns; | |
74 | ||
75 | /* | |
76 | * ignoring sum1 (4 bits) gives a 16ns resolution, which | |
77 | * works due to the async register read. | |
78 | */ | |
79 | sum3 = readl(regs + DTE_NCO_OVERFLOW_REG) & DTE_NCO_SUM3_MASK; | |
80 | sum2 = readl(regs + DTE_NCO_TIME_REG); | |
81 | ns = ((s64)sum3 << DTE_NCO_SUM3_SHIFT) | | |
82 | ((s64)sum2 << DTE_NCO_SUM2_SHIFT); | |
83 | ||
84 | return ns; | |
85 | } | |
86 | ||
87 | static void dte_write_nco_delta(struct ptp_dte *ptp_dte, s64 delta) | |
88 | { | |
89 | s64 ns; | |
90 | ||
91 | ns = dte_read_nco(ptp_dte->regs); | |
92 | ||
93 | /* handle wraparound conditions */ | |
94 | if ((delta < 0) && (abs(delta) > ns)) { | |
95 | if (ptp_dte->ts_wrap_cnt) { | |
96 | ns += DTE_NCO_MAX_NS + delta; | |
97 | ptp_dte->ts_wrap_cnt--; | |
98 | } else { | |
99 | ns = 0; | |
100 | } | |
101 | } else { | |
102 | ns += delta; | |
103 | if (ns > DTE_NCO_MAX_NS) { | |
104 | ptp_dte->ts_wrap_cnt++; | |
105 | ns -= DTE_NCO_MAX_NS; | |
106 | } | |
107 | } | |
108 | ||
109 | dte_write_nco(ptp_dte->regs, ns); | |
110 | ||
111 | ptp_dte->ts_ovf_last = (ns >> DTE_NCO_TS_WRAP_LSHIFT) & | |
112 | DTE_NCO_TS_WRAP_MASK; | |
113 | } | |
114 | ||
115 | static s64 dte_read_nco_with_ovf(struct ptp_dte *ptp_dte) | |
116 | { | |
117 | u32 ts_ovf; | |
118 | s64 ns = 0; | |
119 | ||
120 | ns = dte_read_nco(ptp_dte->regs); | |
121 | ||
122 | /*Timestamp overflow: 8 LSB bits of sum3, 4 MSB bits of sum2 */ | |
123 | ts_ovf = (ns >> DTE_NCO_TS_WRAP_LSHIFT) & DTE_NCO_TS_WRAP_MASK; | |
124 | ||
125 | /* Check for wrap around */ | |
126 | if (ts_ovf < ptp_dte->ts_ovf_last) | |
127 | ptp_dte->ts_wrap_cnt++; | |
128 | ||
129 | ptp_dte->ts_ovf_last = ts_ovf; | |
130 | ||
131 | /* adjust for wraparounds */ | |
132 | ns += (s64)(BIT_ULL(DTE_WRAP_AROUND_NSEC_SHIFT) * ptp_dte->ts_wrap_cnt); | |
133 | ||
134 | return ns; | |
135 | } | |
136 | ||
137 | static int ptp_dte_adjfreq(struct ptp_clock_info *ptp, s32 ppb) | |
138 | { | |
139 | u32 nco_incr; | |
140 | unsigned long flags; | |
141 | struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); | |
142 | ||
143 | if (abs(ppb) > ptp_dte->caps.max_adj) { | |
144 | dev_err(ptp_dte->dev, "ppb adj too big\n"); | |
145 | return -EINVAL; | |
146 | } | |
147 | ||
148 | if (ppb < 0) | |
149 | nco_incr = DTE_NCO_INC_DEFAULT - DTE_PPB_ADJ(ppb); | |
150 | else | |
151 | nco_incr = DTE_NCO_INC_DEFAULT + DTE_PPB_ADJ(ppb); | |
152 | ||
153 | spin_lock_irqsave(&ptp_dte->lock, flags); | |
154 | writel(nco_incr, ptp_dte->regs + DTE_NCO_INC_REG); | |
155 | spin_unlock_irqrestore(&ptp_dte->lock, flags); | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | static int ptp_dte_adjtime(struct ptp_clock_info *ptp, s64 delta) | |
161 | { | |
162 | unsigned long flags; | |
163 | struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); | |
164 | ||
165 | spin_lock_irqsave(&ptp_dte->lock, flags); | |
166 | dte_write_nco_delta(ptp_dte, delta); | |
167 | spin_unlock_irqrestore(&ptp_dte->lock, flags); | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | static int ptp_dte_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) | |
173 | { | |
174 | unsigned long flags; | |
175 | struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); | |
176 | ||
177 | spin_lock_irqsave(&ptp_dte->lock, flags); | |
178 | *ts = ns_to_timespec64(dte_read_nco_with_ovf(ptp_dte)); | |
179 | spin_unlock_irqrestore(&ptp_dte->lock, flags); | |
180 | ||
181 | return 0; | |
182 | } | |
183 | ||
184 | static int ptp_dte_settime(struct ptp_clock_info *ptp, | |
185 | const struct timespec64 *ts) | |
186 | { | |
187 | unsigned long flags; | |
188 | struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); | |
189 | ||
190 | spin_lock_irqsave(&ptp_dte->lock, flags); | |
191 | ||
192 | /* Disable nco increment */ | |
193 | writel(0, ptp_dte->regs + DTE_NCO_INC_REG); | |
194 | ||
195 | dte_write_nco(ptp_dte->regs, timespec64_to_ns(ts)); | |
196 | ||
197 | /* reset overflow and wrap counter */ | |
198 | ptp_dte->ts_ovf_last = 0; | |
199 | ptp_dte->ts_wrap_cnt = 0; | |
200 | ||
201 | /* Enable nco increment */ | |
202 | writel(DTE_NCO_INC_DEFAULT, ptp_dte->regs + DTE_NCO_INC_REG); | |
203 | ||
204 | spin_unlock_irqrestore(&ptp_dte->lock, flags); | |
205 | ||
206 | return 0; | |
207 | } | |
208 | ||
209 | static int ptp_dte_enable(struct ptp_clock_info *ptp, | |
210 | struct ptp_clock_request *rq, int on) | |
211 | { | |
212 | return -EOPNOTSUPP; | |
213 | } | |
214 | ||
7d47e9a2 | 215 | static const struct ptp_clock_info ptp_dte_caps = { |
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216 | .owner = THIS_MODULE, |
217 | .name = "DTE PTP timer", | |
218 | .max_adj = 50000000, | |
219 | .n_ext_ts = 0, | |
220 | .n_pins = 0, | |
221 | .pps = 0, | |
222 | .adjfreq = ptp_dte_adjfreq, | |
223 | .adjtime = ptp_dte_adjtime, | |
224 | .gettime64 = ptp_dte_gettime, | |
225 | .settime64 = ptp_dte_settime, | |
226 | .enable = ptp_dte_enable, | |
227 | }; | |
228 | ||
229 | static int ptp_dte_probe(struct platform_device *pdev) | |
230 | { | |
231 | struct ptp_dte *ptp_dte; | |
232 | struct device *dev = &pdev->dev; | |
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233 | |
234 | ptp_dte = devm_kzalloc(dev, sizeof(struct ptp_dte), GFP_KERNEL); | |
235 | if (!ptp_dte) | |
236 | return -ENOMEM; | |
237 | ||
f063d58b | 238 | ptp_dte->regs = devm_platform_ioremap_resource(pdev, 0); |
37f7c66f | 239 | if (IS_ERR(ptp_dte->regs)) |
8a56aa10 | 240 | return PTR_ERR(ptp_dte->regs); |
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241 | |
242 | spin_lock_init(&ptp_dte->lock); | |
243 | ||
244 | ptp_dte->dev = dev; | |
245 | ptp_dte->caps = ptp_dte_caps; | |
246 | ptp_dte->ptp_clk = ptp_clock_register(&ptp_dte->caps, &pdev->dev); | |
247 | if (IS_ERR(ptp_dte->ptp_clk)) { | |
248 | dev_err(dev, | |
249 | "%s: Failed to register ptp clock\n", __func__); | |
250 | return PTR_ERR(ptp_dte->ptp_clk); | |
251 | } | |
252 | ||
253 | platform_set_drvdata(pdev, ptp_dte); | |
254 | ||
255 | dev_info(dev, "ptp clk probe done\n"); | |
256 | ||
257 | return 0; | |
258 | } | |
259 | ||
260 | static int ptp_dte_remove(struct platform_device *pdev) | |
261 | { | |
262 | struct ptp_dte *ptp_dte = platform_get_drvdata(pdev); | |
263 | u8 i; | |
264 | ||
265 | ptp_clock_unregister(ptp_dte->ptp_clk); | |
266 | ||
267 | for (i = 0; i < DTE_NUM_REGS_TO_RESTORE; i++) | |
268 | writel(0, ptp_dte->regs + (i * sizeof(u32))); | |
269 | ||
270 | return 0; | |
271 | } | |
272 | ||
273 | #ifdef CONFIG_PM_SLEEP | |
274 | static int ptp_dte_suspend(struct device *dev) | |
275 | { | |
c0bfdae0 | 276 | struct ptp_dte *ptp_dte = dev_get_drvdata(dev); |
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277 | u8 i; |
278 | ||
279 | for (i = 0; i < DTE_NUM_REGS_TO_RESTORE; i++) { | |
280 | ptp_dte->reg_val[i] = | |
281 | readl(ptp_dte->regs + (i * sizeof(u32))); | |
282 | } | |
283 | ||
284 | /* disable the nco */ | |
285 | writel(0, ptp_dte->regs + DTE_NCO_INC_REG); | |
286 | ||
287 | return 0; | |
288 | } | |
289 | ||
290 | static int ptp_dte_resume(struct device *dev) | |
291 | { | |
c0bfdae0 | 292 | struct ptp_dte *ptp_dte = dev_get_drvdata(dev); |
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293 | u8 i; |
294 | ||
295 | for (i = 0; i < DTE_NUM_REGS_TO_RESTORE; i++) { | |
296 | if ((i * sizeof(u32)) != DTE_NCO_OVERFLOW_REG) | |
297 | writel(ptp_dte->reg_val[i], | |
298 | (ptp_dte->regs + (i * sizeof(u32)))); | |
299 | else | |
300 | writel(((ptp_dte->reg_val[i] & | |
301 | DTE_NCO_SUM3_MASK) << DTE_NCO_SUM3_WR_SHIFT), | |
302 | (ptp_dte->regs + (i * sizeof(u32)))); | |
303 | } | |
304 | ||
305 | return 0; | |
306 | } | |
307 | ||
308 | static const struct dev_pm_ops ptp_dte_pm_ops = { | |
309 | .suspend = ptp_dte_suspend, | |
310 | .resume = ptp_dte_resume | |
311 | }; | |
312 | ||
313 | #define PTP_DTE_PM_OPS (&ptp_dte_pm_ops) | |
314 | #else | |
315 | #define PTP_DTE_PM_OPS NULL | |
316 | #endif | |
317 | ||
318 | static const struct of_device_id ptp_dte_of_match[] = { | |
319 | { .compatible = "brcm,ptp-dte", }, | |
320 | {}, | |
321 | }; | |
322 | MODULE_DEVICE_TABLE(of, ptp_dte_of_match); | |
323 | ||
324 | static struct platform_driver ptp_dte_driver = { | |
325 | .driver = { | |
326 | .name = "ptp-dte", | |
327 | .pm = PTP_DTE_PM_OPS, | |
328 | .of_match_table = ptp_dte_of_match, | |
329 | }, | |
330 | .probe = ptp_dte_probe, | |
331 | .remove = ptp_dte_remove, | |
332 | }; | |
333 | module_platform_driver(ptp_dte_driver); | |
334 | ||
335 | MODULE_AUTHOR("Broadcom"); | |
336 | MODULE_DESCRIPTION("Broadcom DTE PTP Clock driver"); | |
337 | MODULE_LICENSE("GPL v2"); |