1 /*******************************************************************************
2 PTP 1588 clock using the STMMAC.
3
4 Copyright (C) 2013 Vayavya Labs Pvt Ltd
5
6 This program is free software; you can redistribute it and/or modify it
7 under the terms and conditions of the GNU General Public License,
8 version 2, as published by the Free Software Foundation.
9
10 This program is distributed in the hope it will be useful, but WITHOUT
11 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 more details.
14
15 You should have received a copy of the GNU General Public License along with
16 this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18
19 The full GNU General Public License is included in this distribution in
20 the file called "COPYING".
21
22 Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
23 *******************************************************************************/
24 #include "stmmac.h"
25 #include "stmmac_ptp.h"
26
27 /**
28 * stmmac_adjust_freq
29 *
30 * @ptp: pointer to ptp_clock_info structure
31 * @ppb: desired period change in parts ber billion
32 *
33 * Description: this function will adjust the frequency of hardware clock.
34 */
stmmac_adjust_freq(struct ptp_clock_info * ptp,s32 ppb)35 static int stmmac_adjust_freq(struct ptp_clock_info *ptp, s32 ppb)
36 {
37 struct stmmac_priv *priv =
38 container_of(ptp, struct stmmac_priv, ptp_clock_ops);
39 unsigned long flags;
40 u32 diff, addend;
41 int neg_adj = 0;
42 u64 adj;
43
44 if (ppb < 0) {
45 neg_adj = 1;
46 ppb = -ppb;
47 }
48
49 addend = priv->default_addend;
50 adj = addend;
51 adj *= ppb;
52 diff = div_u64(adj, 1000000000ULL);
53 addend = neg_adj ? (addend - diff) : (addend + diff);
54
55 spin_lock_irqsave(&priv->ptp_lock, flags);
56
57 priv->hw->ptp->config_addend(priv->ptpaddr, addend);
58
59 spin_unlock_irqrestore(&priv->ptp_lock, flags);
60
61 return 0;
62 }
63
64 /**
65 * stmmac_adjust_time
66 *
67 * @ptp: pointer to ptp_clock_info structure
68 * @delta: desired change in nanoseconds
69 *
70 * Description: this function will shift/adjust the hardware clock time.
71 */
stmmac_adjust_time(struct ptp_clock_info * ptp,s64 delta)72 static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
73 {
74 struct stmmac_priv *priv =
75 container_of(ptp, struct stmmac_priv, ptp_clock_ops);
76 unsigned long flags;
77 u32 sec, nsec;
78 u32 quotient, reminder;
79 int neg_adj = 0;
80
81 if (delta < 0) {
82 neg_adj = 1;
83 delta = -delta;
84 }
85
86 quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
87 sec = quotient;
88 nsec = reminder;
89
90 spin_lock_irqsave(&priv->ptp_lock, flags);
91
92 priv->hw->ptp->adjust_systime(priv->ptpaddr, sec, nsec, neg_adj,
93 priv->plat->has_gmac4);
94
95 spin_unlock_irqrestore(&priv->ptp_lock, flags);
96
97 return 0;
98 }
99
100 /**
101 * stmmac_get_time
102 *
103 * @ptp: pointer to ptp_clock_info structure
104 * @ts: pointer to hold time/result
105 *
106 * Description: this function will read the current time from the
107 * hardware clock and store it in @ts.
108 */
stmmac_get_time(struct ptp_clock_info * ptp,struct timespec64 * ts)109 static int stmmac_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
110 {
111 struct stmmac_priv *priv =
112 container_of(ptp, struct stmmac_priv, ptp_clock_ops);
113 unsigned long flags;
114 u64 ns;
115
116 spin_lock_irqsave(&priv->ptp_lock, flags);
117
118 ns = priv->hw->ptp->get_systime(priv->ptpaddr);
119
120 spin_unlock_irqrestore(&priv->ptp_lock, flags);
121
122 *ts = ns_to_timespec64(ns);
123
124 return 0;
125 }
126
127 /**
128 * stmmac_set_time
129 *
130 * @ptp: pointer to ptp_clock_info structure
131 * @ts: time value to set
132 *
133 * Description: this function will set the current time on the
134 * hardware clock.
135 */
stmmac_set_time(struct ptp_clock_info * ptp,const struct timespec64 * ts)136 static int stmmac_set_time(struct ptp_clock_info *ptp,
137 const struct timespec64 *ts)
138 {
139 struct stmmac_priv *priv =
140 container_of(ptp, struct stmmac_priv, ptp_clock_ops);
141 unsigned long flags;
142
143 spin_lock_irqsave(&priv->ptp_lock, flags);
144
145 priv->hw->ptp->init_systime(priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
146
147 spin_unlock_irqrestore(&priv->ptp_lock, flags);
148
149 return 0;
150 }
151
stmmac_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * rq,int on)152 static int stmmac_enable(struct ptp_clock_info *ptp,
153 struct ptp_clock_request *rq, int on)
154 {
155 return -EOPNOTSUPP;
156 }
157
158 /* structure describing a PTP hardware clock */
159 static struct ptp_clock_info stmmac_ptp_clock_ops = {
160 .owner = THIS_MODULE,
161 .name = "stmmac_ptp_clock",
162 .max_adj = 62500000,
163 .n_alarm = 0,
164 .n_ext_ts = 0,
165 .n_per_out = 0,
166 .n_pins = 0,
167 .pps = 0,
168 .adjfreq = stmmac_adjust_freq,
169 .adjtime = stmmac_adjust_time,
170 .gettime64 = stmmac_get_time,
171 .settime64 = stmmac_set_time,
172 .enable = stmmac_enable,
173 };
174
175 /**
176 * stmmac_ptp_register
177 * @priv: driver private structure
178 * Description: this function will register the ptp clock driver
179 * to kernel. It also does some house keeping work.
180 */
stmmac_ptp_register(struct stmmac_priv * priv)181 void stmmac_ptp_register(struct stmmac_priv *priv)
182 {
183 spin_lock_init(&priv->ptp_lock);
184 priv->ptp_clock_ops = stmmac_ptp_clock_ops;
185
186 priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
187 priv->device);
188 if (IS_ERR(priv->ptp_clock)) {
189 netdev_err(priv->dev, "ptp_clock_register failed\n");
190 priv->ptp_clock = NULL;
191 } else if (priv->ptp_clock)
192 netdev_info(priv->dev, "registered PTP clock\n");
193 }
194
195 /**
196 * stmmac_ptp_unregister
197 * @priv: driver private structure
198 * Description: this function will remove/unregister the ptp clock driver
199 * from the kernel.
200 */
stmmac_ptp_unregister(struct stmmac_priv * priv)201 void stmmac_ptp_unregister(struct stmmac_priv *priv)
202 {
203 if (priv->ptp_clock) {
204 ptp_clock_unregister(priv->ptp_clock);
205 priv->ptp_clock = NULL;
206 pr_debug("Removed PTP HW clock successfully on %s\n",
207 priv->dev->name);
208 }
209 }
210