xref: /linux/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c (revision 8a5f956a9fb7d74fff681145082acfad5afa6bb8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*******************************************************************************
3   Copyright (C) 2013  Vayavya Labs Pvt Ltd
4 
5   This implements all the API for managing HW timestamp & PTP.
6 
7 
8   Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
9   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
10 *******************************************************************************/
11 
12 #include <linux/io.h>
13 #include <linux/iopoll.h>
14 #include <linux/delay.h>
15 #include <linux/ptp_clock_kernel.h>
16 #include "common.h"
17 #include "stmmac_ptp.h"
18 #include "dwmac4.h"
19 #include "stmmac.h"
20 
21 #define STMMAC_HWTS_CFG_MASK	(PTP_TCR_TSENA | PTP_TCR_TSCFUPDT | \
22 				 PTP_TCR_TSINIT | PTP_TCR_TSUPDT | \
23 				 PTP_TCR_TSCTRLSSR | PTP_TCR_SNAPTYPSEL_1 | \
24 				 PTP_TCR_TSIPV4ENA | PTP_TCR_TSIPV6ENA | \
25 				 PTP_TCR_TSEVNTENA | PTP_TCR_TSMSTRENA | \
26 				 PTP_TCR_TSVER2ENA | PTP_TCR_TSIPENA | \
27 				 PTP_TCR_TSTRIG | PTP_TCR_TSENALL)
28 
29 static void config_hw_tstamping(void __iomem *ioaddr, u32 data)
30 {
31 	u32 regval = readl(ioaddr + PTP_TCR);
32 
33 	regval &= ~STMMAC_HWTS_CFG_MASK;
34 	regval |= data;
35 
36 	writel(regval, ioaddr + PTP_TCR);
37 }
38 
39 static void config_sub_second_increment(void __iomem *ioaddr,
40 		u32 ptp_clock, int gmac4, u32 *ssinc)
41 {
42 	u32 value = readl(ioaddr + PTP_TCR);
43 	unsigned long data;
44 	u32 reg_value;
45 
46 	/* For GMAC3.x, 4.x versions, in "fine adjustement mode" set sub-second
47 	 * increment to twice the number of nanoseconds of a clock cycle.
48 	 * The calculation of the default_addend value by the caller will set it
49 	 * to mid-range = 2^31 when the remainder of this division is zero,
50 	 * which will make the accumulator overflow once every 2 ptp_clock
51 	 * cycles, adding twice the number of nanoseconds of a clock cycle :
52 	 * 2000000000ULL / ptp_clock.
53 	 */
54 	if (value & PTP_TCR_TSCFUPDT)
55 		data = (2000000000ULL / ptp_clock);
56 	else
57 		data = (1000000000ULL / ptp_clock);
58 
59 	/* 0.465ns accuracy */
60 	if (!(value & PTP_TCR_TSCTRLSSR))
61 		data = (data * 1000) / 465;
62 
63 	if (data > PTP_SSIR_SSINC_MAX)
64 		data = PTP_SSIR_SSINC_MAX;
65 
66 	reg_value = data;
67 	if (gmac4)
68 		reg_value <<= GMAC4_PTP_SSIR_SSINC_SHIFT;
69 
70 	writel(reg_value, ioaddr + PTP_SSIR);
71 
72 	if (ssinc)
73 		*ssinc = data;
74 }
75 
76 static void hwtstamp_correct_latency(struct stmmac_priv *priv)
77 {
78 	void __iomem *ioaddr = priv->ptpaddr;
79 	u32 reg_tsic, reg_tsicsns;
80 	u32 reg_tsec, reg_tsecsns;
81 	u64 scaled_ns;
82 	u32 val;
83 
84 	/* MAC-internal ingress latency */
85 	scaled_ns = readl(ioaddr + PTP_TS_INGR_LAT);
86 
87 	/* See section 11.7.2.5.3.1 "Ingress Correction" on page 4001 of
88 	 * i.MX8MP Applications Processor Reference Manual Rev. 1, 06/2021
89 	 */
90 	val = readl(ioaddr + PTP_TCR);
91 	if (val & PTP_TCR_TSCTRLSSR)
92 		/* nanoseconds field is in decimal format with granularity of 1ns/bit */
93 		scaled_ns = ((u64)NSEC_PER_SEC << 16) - scaled_ns;
94 	else
95 		/* nanoseconds field is in binary format with granularity of ~0.466ns/bit */
96 		scaled_ns = ((1ULL << 31) << 16) -
97 			DIV_U64_ROUND_CLOSEST(scaled_ns * PSEC_PER_NSEC, 466U);
98 
99 	reg_tsic = scaled_ns >> 16;
100 	reg_tsicsns = scaled_ns & 0xff00;
101 
102 	/* set bit 31 for 2's compliment */
103 	reg_tsic |= BIT(31);
104 
105 	writel(reg_tsic, ioaddr + PTP_TS_INGR_CORR_NS);
106 	writel(reg_tsicsns, ioaddr + PTP_TS_INGR_CORR_SNS);
107 
108 	/* MAC-internal egress latency */
109 	scaled_ns = readl(ioaddr + PTP_TS_EGR_LAT);
110 
111 	reg_tsec = scaled_ns >> 16;
112 	reg_tsecsns = scaled_ns & 0xff00;
113 
114 	writel(reg_tsec, ioaddr + PTP_TS_EGR_CORR_NS);
115 	writel(reg_tsecsns, ioaddr + PTP_TS_EGR_CORR_SNS);
116 }
117 
118 static int init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
119 {
120 	u32 value;
121 
122 	writel(sec, ioaddr + PTP_STSUR);
123 	writel(nsec, ioaddr + PTP_STNSUR);
124 	/* issue command to initialize the system time value */
125 	value = readl(ioaddr + PTP_TCR);
126 	value |= PTP_TCR_TSINIT;
127 	writel(value, ioaddr + PTP_TCR);
128 
129 	/* wait for present system time initialize to complete */
130 	return readl_poll_timeout_atomic(ioaddr + PTP_TCR, value,
131 				 !(value & PTP_TCR_TSINIT),
132 				 10, 100000);
133 }
134 
135 static int config_addend(void __iomem *ioaddr, u32 addend)
136 {
137 	u32 value;
138 
139 	writel(addend, ioaddr + PTP_TAR);
140 	/* issue command to update the addend value */
141 	value = readl(ioaddr + PTP_TCR);
142 	value |= PTP_TCR_TSADDREG;
143 	writel(value, ioaddr + PTP_TCR);
144 
145 	/* wait for present addend update to complete */
146 	return readl_poll_timeout_atomic(ioaddr + PTP_TCR, value,
147 					 !(value & PTP_TCR_TSADDREG),
148 					 10, 100000);
149 }
150 
151 static int adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
152 		int add_sub, int gmac4)
153 {
154 	u32 value;
155 
156 	if (add_sub) {
157 		/* If the new sec value needs to be subtracted with
158 		 * the system time, then MAC_STSUR reg should be
159 		 * programmed with (2^32 – <new_sec_value>)
160 		 */
161 		if (gmac4)
162 			sec = -sec;
163 
164 		value = readl(ioaddr + PTP_TCR);
165 		if (value & PTP_TCR_TSCTRLSSR)
166 			nsec = (PTP_DIGITAL_ROLLOVER_MODE - nsec);
167 		else
168 			nsec = (PTP_BINARY_ROLLOVER_MODE - nsec);
169 	}
170 
171 	writel(sec, ioaddr + PTP_STSUR);
172 	value = (add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec;
173 	writel(value, ioaddr + PTP_STNSUR);
174 
175 	/* issue command to initialize the system time value */
176 	value = readl(ioaddr + PTP_TCR);
177 	value |= PTP_TCR_TSUPDT;
178 	writel(value, ioaddr + PTP_TCR);
179 
180 	/* wait for present system time adjust/update to complete */
181 	return readl_poll_timeout_atomic(ioaddr + PTP_TCR, value,
182 					 !(value & PTP_TCR_TSUPDT),
183 					 10, 100000);
184 }
185 
186 static void get_systime(void __iomem *ioaddr, u64 *systime)
187 {
188 	u64 ns, sec0, sec1;
189 
190 	/* Get the TSS value */
191 	sec1 = readl_relaxed(ioaddr + PTP_STSR);
192 	do {
193 		sec0 = sec1;
194 		/* Get the TSSS value */
195 		ns = readl_relaxed(ioaddr + PTP_STNSR);
196 		/* Get the TSS value */
197 		sec1 = readl_relaxed(ioaddr + PTP_STSR);
198 	} while (sec0 != sec1);
199 
200 	if (systime)
201 		*systime = ns + (sec1 * 1000000000ULL);
202 }
203 
204 static void get_ptptime(void __iomem *ptpaddr, u64 *ptp_time)
205 {
206 	u64 ns;
207 
208 	ns = readl(ptpaddr + PTP_ATNR);
209 	ns += (u64)readl(ptpaddr + PTP_ATSR) * NSEC_PER_SEC;
210 
211 	*ptp_time = ns;
212 }
213 
214 static void timestamp_interrupt(struct stmmac_priv *priv)
215 {
216 	u32 num_snapshot, ts_status, tsync_int;
217 	struct ptp_clock_event event;
218 	u32 acr_value, channel;
219 	unsigned long flags;
220 	u64 ptp_time;
221 	int i;
222 
223 	if (priv->plat->flags & STMMAC_FLAG_INT_SNAPSHOT_EN) {
224 		wake_up(&priv->tstamp_busy_wait);
225 		return;
226 	}
227 
228 	tsync_int = readl(priv->ioaddr + GMAC_INT_STATUS) & GMAC_INT_TSIE;
229 
230 	if (!tsync_int)
231 		return;
232 
233 	/* Read timestamp status to clear interrupt from either external
234 	 * timestamp or start/end of PPS.
235 	 */
236 	ts_status = readl(priv->ioaddr + GMAC_TIMESTAMP_STATUS);
237 
238 	if (!(priv->plat->flags & STMMAC_FLAG_EXT_SNAPSHOT_EN))
239 		return;
240 
241 	num_snapshot = (ts_status & GMAC_TIMESTAMP_ATSNS_MASK) >>
242 		       GMAC_TIMESTAMP_ATSNS_SHIFT;
243 
244 	acr_value = readl(priv->ptpaddr + PTP_ACR);
245 	channel = ilog2(FIELD_GET(PTP_ACR_MASK, acr_value));
246 
247 	for (i = 0; i < num_snapshot; i++) {
248 		read_lock_irqsave(&priv->ptp_lock, flags);
249 		get_ptptime(priv->ptpaddr, &ptp_time);
250 		read_unlock_irqrestore(&priv->ptp_lock, flags);
251 		event.type = PTP_CLOCK_EXTTS;
252 		event.index = channel;
253 		event.timestamp = ptp_time;
254 		ptp_clock_event(priv->ptp_clock, &event);
255 	}
256 }
257 
258 const struct stmmac_hwtimestamp stmmac_ptp = {
259 	.config_hw_tstamping = config_hw_tstamping,
260 	.init_systime = init_systime,
261 	.config_sub_second_increment = config_sub_second_increment,
262 	.config_addend = config_addend,
263 	.adjust_systime = adjust_systime,
264 	.get_systime = get_systime,
265 	.get_ptptime = get_ptptime,
266 	.timestamp_interrupt = timestamp_interrupt,
267 	.hwtstamp_correct_latency = hwtstamp_correct_latency,
268 };
269 
270 const struct stmmac_hwtimestamp dwmac1000_ptp = {
271 	.config_hw_tstamping = config_hw_tstamping,
272 	.init_systime = init_systime,
273 	.config_sub_second_increment = config_sub_second_increment,
274 	.config_addend = config_addend,
275 	.adjust_systime = adjust_systime,
276 	.get_systime = get_systime,
277 	.get_ptptime = dwmac1000_get_ptptime,
278 	.timestamp_interrupt = dwmac1000_timestamp_interrupt,
279 };
280