xref: /linux/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
1 /*******************************************************************************
2   Copyright (C) 2013  Vayavya Labs Pvt Ltd
3 
4   This implements all the API for managing HW timestamp & PTP.
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   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
24 *******************************************************************************/
25 
26 #include <linux/io.h>
27 #include <linux/delay.h>
28 #include "common.h"
29 #include "stmmac_ptp.h"
30 
31 static void stmmac_config_hw_tstamping(void __iomem *ioaddr, u32 data)
32 {
33 	writel(data, ioaddr + PTP_TCR);
34 }
35 
36 static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
37 					      u32 ptp_clock)
38 {
39 	u32 value = readl(ioaddr + PTP_TCR);
40 	unsigned long data;
41 
42 	/* Convert the ptp_clock to nano second
43 	 * formula = (2/ptp_clock) * 1000000000
44 	 * where, ptp_clock = 50MHz.
45 	 */
46 	data = (2000000000ULL / ptp_clock);
47 
48 	/* 0.465ns accuracy */
49 	if (!(value & PTP_TCR_TSCTRLSSR))
50 		data = (data * 1000) / 465;
51 
52 	writel(data, ioaddr + PTP_SSIR);
53 
54 	return data;
55 }
56 
57 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
58 {
59 	int limit;
60 	u32 value;
61 
62 	writel(sec, ioaddr + PTP_STSUR);
63 	writel(nsec, ioaddr + PTP_STNSUR);
64 	/* issue command to initialize the system time value */
65 	value = readl(ioaddr + PTP_TCR);
66 	value |= PTP_TCR_TSINIT;
67 	writel(value, ioaddr + PTP_TCR);
68 
69 	/* wait for present system time initialize to complete */
70 	limit = 10;
71 	while (limit--) {
72 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSINIT))
73 			break;
74 		mdelay(10);
75 	}
76 	if (limit < 0)
77 		return -EBUSY;
78 
79 	return 0;
80 }
81 
82 static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
83 {
84 	u32 value;
85 	int limit;
86 
87 	writel(addend, ioaddr + PTP_TAR);
88 	/* issue command to update the addend value */
89 	value = readl(ioaddr + PTP_TCR);
90 	value |= PTP_TCR_TSADDREG;
91 	writel(value, ioaddr + PTP_TCR);
92 
93 	/* wait for present addend update to complete */
94 	limit = 10;
95 	while (limit--) {
96 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSADDREG))
97 			break;
98 		mdelay(10);
99 	}
100 	if (limit < 0)
101 		return -EBUSY;
102 
103 	return 0;
104 }
105 
106 static int stmmac_adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
107 				 int add_sub)
108 {
109 	u32 value;
110 	int limit;
111 
112 	writel(sec, ioaddr + PTP_STSUR);
113 	writel(((add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec),
114 		ioaddr + PTP_STNSUR);
115 	/* issue command to initialize the system time value */
116 	value = readl(ioaddr + PTP_TCR);
117 	value |= PTP_TCR_TSUPDT;
118 	writel(value, ioaddr + PTP_TCR);
119 
120 	/* wait for present system time adjust/update to complete */
121 	limit = 10;
122 	while (limit--) {
123 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSUPDT))
124 			break;
125 		mdelay(10);
126 	}
127 	if (limit < 0)
128 		return -EBUSY;
129 
130 	return 0;
131 }
132 
133 static u64 stmmac_get_systime(void __iomem *ioaddr)
134 {
135 	u64 ns;
136 
137 	ns = readl(ioaddr + PTP_STNSR);
138 	/* convert sec time value to nanosecond */
139 	ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
140 
141 	return ns;
142 }
143 
144 const struct stmmac_hwtimestamp stmmac_ptp = {
145 	.config_hw_tstamping = stmmac_config_hw_tstamping,
146 	.init_systime = stmmac_init_systime,
147 	.config_sub_second_increment = stmmac_config_sub_second_increment,
148 	.config_addend = stmmac_config_addend,
149 	.adjust_systime = stmmac_adjust_systime,
150 	.get_systime = stmmac_get_systime,
151 };
152