xref: /linux/drivers/net/ethernet/engleder/tsnep_ptp.c (revision 41fb0cf1bced59c1fe178cf6cc9f716b5da9e40e)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2021 Gerhard Engleder <gerhard@engleder-embedded.com> */
3 
4 #include "tsnep.h"
5 
6 void tsnep_get_system_time(struct tsnep_adapter *adapter, u64 *time)
7 {
8 	u32 high_before;
9 	u32 low;
10 	u32 high;
11 
12 	/* read high dword twice to detect overrun */
13 	high = ioread32(adapter->addr + ECM_SYSTEM_TIME_HIGH);
14 	do {
15 		low = ioread32(adapter->addr + ECM_SYSTEM_TIME_LOW);
16 		high_before = high;
17 		high = ioread32(adapter->addr + ECM_SYSTEM_TIME_HIGH);
18 	} while (high != high_before);
19 	*time = (((u64)high) << 32) | ((u64)low);
20 }
21 
22 int tsnep_ptp_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
23 {
24 	struct tsnep_adapter *adapter = netdev_priv(netdev);
25 	struct hwtstamp_config config;
26 
27 	if (!ifr)
28 		return -EINVAL;
29 
30 	if (cmd == SIOCSHWTSTAMP) {
31 		if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
32 			return -EFAULT;
33 
34 		if (config.flags)
35 			return -EINVAL;
36 
37 		switch (config.tx_type) {
38 		case HWTSTAMP_TX_OFF:
39 		case HWTSTAMP_TX_ON:
40 			break;
41 		default:
42 			return -ERANGE;
43 		}
44 
45 		switch (config.rx_filter) {
46 		case HWTSTAMP_FILTER_NONE:
47 			break;
48 		case HWTSTAMP_FILTER_ALL:
49 		case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
50 		case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
51 		case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
52 		case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
53 		case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
54 		case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
55 		case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
56 		case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
57 		case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
58 		case HWTSTAMP_FILTER_PTP_V2_EVENT:
59 		case HWTSTAMP_FILTER_PTP_V2_SYNC:
60 		case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
61 		case HWTSTAMP_FILTER_NTP_ALL:
62 			config.rx_filter = HWTSTAMP_FILTER_ALL;
63 			break;
64 		default:
65 			return -ERANGE;
66 		}
67 
68 		memcpy(&adapter->hwtstamp_config, &config,
69 		       sizeof(adapter->hwtstamp_config));
70 	}
71 
72 	if (copy_to_user(ifr->ifr_data, &adapter->hwtstamp_config,
73 			 sizeof(adapter->hwtstamp_config)))
74 		return -EFAULT;
75 
76 	return 0;
77 }
78 
79 static int tsnep_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
80 {
81 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
82 						     ptp_clock_info);
83 	bool negative = false;
84 	u64 rate_offset;
85 
86 	if (scaled_ppm < 0) {
87 		scaled_ppm = -scaled_ppm;
88 		negative = true;
89 	}
90 
91 	/* convert from 16 bit to 32 bit binary fractional, divide by 1000000 to
92 	 * eliminate ppm, multiply with 8 to compensate 8ns clock cycle time,
93 	 * simplify calculation because 15625 * 8 = 1000000 / 8
94 	 */
95 	rate_offset = scaled_ppm;
96 	rate_offset <<= 16 - 3;
97 	rate_offset = div_u64(rate_offset, 15625);
98 
99 	rate_offset &= ECM_CLOCK_RATE_OFFSET_MASK;
100 	if (negative)
101 		rate_offset |= ECM_CLOCK_RATE_OFFSET_SIGN;
102 	iowrite32(rate_offset & 0xFFFFFFFF, adapter->addr + ECM_CLOCK_RATE);
103 
104 	return 0;
105 }
106 
107 static int tsnep_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
108 {
109 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
110 						     ptp_clock_info);
111 	u64 system_time;
112 	unsigned long flags;
113 
114 	spin_lock_irqsave(&adapter->ptp_lock, flags);
115 
116 	tsnep_get_system_time(adapter, &system_time);
117 
118 	system_time += delta;
119 
120 	/* high dword is buffered in hardware and synchronously written to
121 	 * system time when low dword is written
122 	 */
123 	iowrite32(system_time >> 32, adapter->addr + ECM_SYSTEM_TIME_HIGH);
124 	iowrite32(system_time & 0xFFFFFFFF,
125 		  adapter->addr + ECM_SYSTEM_TIME_LOW);
126 
127 	spin_unlock_irqrestore(&adapter->ptp_lock, flags);
128 
129 	return 0;
130 }
131 
132 static int tsnep_ptp_gettimex64(struct ptp_clock_info *ptp,
133 				struct timespec64 *ts,
134 				struct ptp_system_timestamp *sts)
135 {
136 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
137 						     ptp_clock_info);
138 	u32 high_before;
139 	u32 low;
140 	u32 high;
141 	u64 system_time;
142 
143 	/* read high dword twice to detect overrun */
144 	high = ioread32(adapter->addr + ECM_SYSTEM_TIME_HIGH);
145 	do {
146 		ptp_read_system_prets(sts);
147 		low = ioread32(adapter->addr + ECM_SYSTEM_TIME_LOW);
148 		ptp_read_system_postts(sts);
149 		high_before = high;
150 		high = ioread32(adapter->addr + ECM_SYSTEM_TIME_HIGH);
151 	} while (high != high_before);
152 	system_time = (((u64)high) << 32) | ((u64)low);
153 
154 	*ts = ns_to_timespec64(system_time);
155 
156 	return 0;
157 }
158 
159 static int tsnep_ptp_settime64(struct ptp_clock_info *ptp,
160 			       const struct timespec64 *ts)
161 {
162 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
163 						     ptp_clock_info);
164 	u64 system_time = timespec64_to_ns(ts);
165 	unsigned long flags;
166 
167 	spin_lock_irqsave(&adapter->ptp_lock, flags);
168 
169 	/* high dword is buffered in hardware and synchronously written to
170 	 * system time when low dword is written
171 	 */
172 	iowrite32(system_time >> 32, adapter->addr + ECM_SYSTEM_TIME_HIGH);
173 	iowrite32(system_time & 0xFFFFFFFF,
174 		  adapter->addr + ECM_SYSTEM_TIME_LOW);
175 
176 	spin_unlock_irqrestore(&adapter->ptp_lock, flags);
177 
178 	return 0;
179 }
180 
181 int tsnep_ptp_init(struct tsnep_adapter *adapter)
182 {
183 	int retval = 0;
184 
185 	adapter->hwtstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
186 	adapter->hwtstamp_config.tx_type = HWTSTAMP_TX_OFF;
187 
188 	snprintf(adapter->ptp_clock_info.name, 16, "%s", TSNEP);
189 	adapter->ptp_clock_info.owner = THIS_MODULE;
190 	/* at most 2^-1ns adjustment every clock cycle for 8ns clock cycle time,
191 	 * stay slightly below because only bits below 2^-1ns are supported
192 	 */
193 	adapter->ptp_clock_info.max_adj = (500000000 / 8 - 1);
194 	adapter->ptp_clock_info.adjfine = tsnep_ptp_adjfine;
195 	adapter->ptp_clock_info.adjtime = tsnep_ptp_adjtime;
196 	adapter->ptp_clock_info.gettimex64 = tsnep_ptp_gettimex64;
197 	adapter->ptp_clock_info.settime64 = tsnep_ptp_settime64;
198 
199 	spin_lock_init(&adapter->ptp_lock);
200 
201 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
202 						&adapter->pdev->dev);
203 	if (IS_ERR(adapter->ptp_clock)) {
204 		netdev_err(adapter->netdev, "ptp_clock_register failed\n");
205 
206 		retval = PTR_ERR(adapter->ptp_clock);
207 		adapter->ptp_clock = NULL;
208 	} else if (adapter->ptp_clock) {
209 		netdev_info(adapter->netdev, "PHC added\n");
210 	}
211 
212 	return retval;
213 }
214 
215 void tsnep_ptp_cleanup(struct tsnep_adapter *adapter)
216 {
217 	if (adapter->ptp_clock) {
218 		ptp_clock_unregister(adapter->ptp_clock);
219 		netdev_info(adapter->netdev, "PHC removed\n");
220 	}
221 }
222