xref: /linux/drivers/net/ethernet/engleder/tsnep_ptp.c (revision 8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88)
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_hwtstamp_get(struct net_device *netdev,
23 			   struct kernel_hwtstamp_config *config)
24 {
25 	struct tsnep_adapter *adapter = netdev_priv(netdev);
26 
27 	*config = adapter->hwtstamp_config;
28 	return 0;
29 }
30 
31 int tsnep_ptp_hwtstamp_set(struct net_device *netdev,
32 			   struct kernel_hwtstamp_config *config,
33 			   struct netlink_ext_ack *extack)
34 {
35 	struct tsnep_adapter *adapter = netdev_priv(netdev);
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 	adapter->hwtstamp_config = *config;
69 	return 0;
70 }
71 
72 static int tsnep_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
73 {
74 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
75 						     ptp_clock_info);
76 	bool negative = false;
77 	u64 rate_offset;
78 
79 	if (scaled_ppm < 0) {
80 		scaled_ppm = -scaled_ppm;
81 		negative = true;
82 	}
83 
84 	/* convert from 16 bit to 32 bit binary fractional, divide by 1000000 to
85 	 * eliminate ppm, multiply with 8 to compensate 8ns clock cycle time,
86 	 * simplify calculation because 15625 * 8 = 1000000 / 8
87 	 */
88 	rate_offset = scaled_ppm;
89 	rate_offset <<= 16 - 3;
90 	rate_offset = div_u64(rate_offset, 15625);
91 
92 	rate_offset &= ECM_CLOCK_RATE_OFFSET_MASK;
93 	if (negative)
94 		rate_offset |= ECM_CLOCK_RATE_OFFSET_SIGN;
95 	iowrite32(rate_offset & 0xFFFFFFFF, adapter->addr + ECM_CLOCK_RATE);
96 
97 	return 0;
98 }
99 
100 static int tsnep_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
101 {
102 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
103 						     ptp_clock_info);
104 	u64 system_time;
105 	unsigned long flags;
106 
107 	spin_lock_irqsave(&adapter->ptp_lock, flags);
108 
109 	tsnep_get_system_time(adapter, &system_time);
110 
111 	system_time += delta;
112 
113 	/* high dword is buffered in hardware and synchronously written to
114 	 * system time when low dword is written
115 	 */
116 	iowrite32(system_time >> 32, adapter->addr + ECM_SYSTEM_TIME_HIGH);
117 	iowrite32(system_time & 0xFFFFFFFF,
118 		  adapter->addr + ECM_SYSTEM_TIME_LOW);
119 
120 	spin_unlock_irqrestore(&adapter->ptp_lock, flags);
121 
122 	return 0;
123 }
124 
125 static int tsnep_ptp_gettimex64(struct ptp_clock_info *ptp,
126 				struct timespec64 *ts,
127 				struct ptp_system_timestamp *sts)
128 {
129 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
130 						     ptp_clock_info);
131 	u32 high_before;
132 	u32 low;
133 	u32 high;
134 	u64 system_time;
135 
136 	/* read high dword twice to detect overrun */
137 	high = ioread32(adapter->addr + ECM_SYSTEM_TIME_HIGH);
138 	do {
139 		ptp_read_system_prets(sts);
140 		low = ioread32(adapter->addr + ECM_SYSTEM_TIME_LOW);
141 		ptp_read_system_postts(sts);
142 		high_before = high;
143 		high = ioread32(adapter->addr + ECM_SYSTEM_TIME_HIGH);
144 	} while (high != high_before);
145 	system_time = (((u64)high) << 32) | ((u64)low);
146 
147 	*ts = ns_to_timespec64(system_time);
148 
149 	return 0;
150 }
151 
152 static int tsnep_ptp_settime64(struct ptp_clock_info *ptp,
153 			       const struct timespec64 *ts)
154 {
155 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
156 						     ptp_clock_info);
157 	u64 system_time = timespec64_to_ns(ts);
158 	unsigned long flags;
159 
160 	spin_lock_irqsave(&adapter->ptp_lock, flags);
161 
162 	/* high dword is buffered in hardware and synchronously written to
163 	 * system time when low dword is written
164 	 */
165 	iowrite32(system_time >> 32, adapter->addr + ECM_SYSTEM_TIME_HIGH);
166 	iowrite32(system_time & 0xFFFFFFFF,
167 		  adapter->addr + ECM_SYSTEM_TIME_LOW);
168 
169 	spin_unlock_irqrestore(&adapter->ptp_lock, flags);
170 
171 	return 0;
172 }
173 
174 static int tsnep_ptp_getcyclesx64(struct ptp_clock_info *ptp,
175 				  struct timespec64 *ts,
176 				  struct ptp_system_timestamp *sts)
177 {
178 	struct tsnep_adapter *adapter = container_of(ptp, struct tsnep_adapter,
179 						     ptp_clock_info);
180 	u32 high_before;
181 	u32 low;
182 	u32 high;
183 	u64 counter;
184 
185 	/* read high dword twice to detect overrun */
186 	high = ioread32(adapter->addr + ECM_COUNTER_HIGH);
187 	do {
188 		ptp_read_system_prets(sts);
189 		low = ioread32(adapter->addr + ECM_COUNTER_LOW);
190 		ptp_read_system_postts(sts);
191 		high_before = high;
192 		high = ioread32(adapter->addr + ECM_COUNTER_HIGH);
193 	} while (high != high_before);
194 	counter = (((u64)high) << 32) | ((u64)low);
195 
196 	*ts = ns_to_timespec64(counter);
197 
198 	return 0;
199 }
200 
201 int tsnep_ptp_init(struct tsnep_adapter *adapter)
202 {
203 	int retval = 0;
204 
205 	adapter->hwtstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
206 	adapter->hwtstamp_config.tx_type = HWTSTAMP_TX_OFF;
207 
208 	snprintf(adapter->ptp_clock_info.name, 16, "%s", TSNEP);
209 	adapter->ptp_clock_info.owner = THIS_MODULE;
210 	/* at most 2^-1ns adjustment every clock cycle for 8ns clock cycle time,
211 	 * stay slightly below because only bits below 2^-1ns are supported
212 	 */
213 	adapter->ptp_clock_info.max_adj = (500000000 / 8 - 1);
214 	adapter->ptp_clock_info.adjfine = tsnep_ptp_adjfine;
215 	adapter->ptp_clock_info.adjtime = tsnep_ptp_adjtime;
216 	adapter->ptp_clock_info.gettimex64 = tsnep_ptp_gettimex64;
217 	adapter->ptp_clock_info.settime64 = tsnep_ptp_settime64;
218 	adapter->ptp_clock_info.getcyclesx64 = tsnep_ptp_getcyclesx64;
219 
220 	spin_lock_init(&adapter->ptp_lock);
221 
222 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
223 						&adapter->pdev->dev);
224 	if (IS_ERR(adapter->ptp_clock)) {
225 		netdev_err(adapter->netdev, "ptp_clock_register failed\n");
226 
227 		retval = PTR_ERR(adapter->ptp_clock);
228 		adapter->ptp_clock = NULL;
229 	} else if (adapter->ptp_clock) {
230 		netdev_info(adapter->netdev, "PHC added\n");
231 	}
232 
233 	return retval;
234 }
235 
236 void tsnep_ptp_cleanup(struct tsnep_adapter *adapter)
237 {
238 	if (adapter->ptp_clock) {
239 		ptp_clock_unregister(adapter->ptp_clock);
240 		netdev_info(adapter->netdev, "PHC removed\n");
241 	}
242 }
243