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

source code of linux/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c