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 void stmmac_config_sub_second_increment(void __iomem *ioaddr)
37 {
38 	u32 value = readl(ioaddr + PTP_TCR);
39 	unsigned long data;
40 
41 	/* Convert the ptp_clock to nano second
42 	 * formula = (1/ptp_clock) * 1000000000
43 	 * where, ptp_clock = 50MHz.
44 	 */
45 	data = (1000000000ULL / 50000000);
46 
47 	/* 0.465ns accuracy */
48 	if (!(value & PTP_TCR_TSCTRLSSR))
49 		data = (data * 1000) / 465;
50 
51 	writel(data, ioaddr + PTP_SSIR);
52 }
53 
54 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
55 {
56 	int limit;
57 	u32 value;
58 
59 	writel(sec, ioaddr + PTP_STSUR);
60 	writel(nsec, ioaddr + PTP_STNSUR);
61 	/* issue command to initialize the system time value */
62 	value = readl(ioaddr + PTP_TCR);
63 	value |= PTP_TCR_TSINIT;
64 	writel(value, ioaddr + PTP_TCR);
65 
66 	/* wait for present system time initialize to complete */
67 	limit = 10;
68 	while (limit--) {
69 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSINIT))
70 			break;
71 		mdelay(10);
72 	}
73 	if (limit < 0)
74 		return -EBUSY;
75 
76 	return 0;
77 }
78 
79 static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
80 {
81 	u32 value;
82 	int limit;
83 
84 	writel(addend, ioaddr + PTP_TAR);
85 	/* issue command to update the addend value */
86 	value = readl(ioaddr + PTP_TCR);
87 	value |= PTP_TCR_TSADDREG;
88 	writel(value, ioaddr + PTP_TCR);
89 
90 	/* wait for present addend update to complete */
91 	limit = 10;
92 	while (limit--) {
93 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSADDREG))
94 			break;
95 		mdelay(10);
96 	}
97 	if (limit < 0)
98 		return -EBUSY;
99 
100 	return 0;
101 }
102 
103 static int stmmac_adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
104 				 int add_sub)
105 {
106 	u32 value;
107 	int limit;
108 
109 	writel(sec, ioaddr + PTP_STSUR);
110 	writel(((add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec),
111 		ioaddr + PTP_STNSUR);
112 	/* issue command to initialize the system time value */
113 	value = readl(ioaddr + PTP_TCR);
114 	value |= PTP_TCR_TSUPDT;
115 	writel(value, ioaddr + PTP_TCR);
116 
117 	/* wait for present system time adjust/update to complete */
118 	limit = 10;
119 	while (limit--) {
120 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSUPDT))
121 			break;
122 		mdelay(10);
123 	}
124 	if (limit < 0)
125 		return -EBUSY;
126 
127 	return 0;
128 }
129 
130 static u64 stmmac_get_systime(void __iomem *ioaddr)
131 {
132 	u64 ns;
133 
134 	ns = readl(ioaddr + PTP_STNSR);
135 	/* convert sec time value to nanosecond */
136 	ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
137 
138 	return ns;
139 }
140 
141 const struct stmmac_hwtimestamp stmmac_ptp = {
142 	.config_hw_tstamping = stmmac_config_hw_tstamping,
143 	.init_systime = stmmac_init_systime,
144 	.config_sub_second_increment = stmmac_config_sub_second_increment,
145 	.config_addend = stmmac_config_addend,
146 	.adjust_systime = stmmac_adjust_systime,
147 	.get_systime = stmmac_get_systime,
148 };
149