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, int gmac4)
38 {
39 	u32 value = readl(ioaddr + PTP_TCR);
40 	unsigned long data;
41 
42 	/* For GMAC3.x, 4.x versions, convert the ptp_clock to nano second
43 	 *	formula = (1/ptp_clock) * 1000000000
44 	 * where ptp_clock is 50MHz if fine method is used to update system
45 	 */
46 	if (value & PTP_TCR_TSCFUPDT)
47 		data = (1000000000ULL / 50000000);
48 	else
49 		data = (1000000000ULL / ptp_clock);
50 
51 	/* 0.465ns accuracy */
52 	if (!(value & PTP_TCR_TSCTRLSSR))
53 		data = (data * 1000) / 465;
54 
55 	data &= PTP_SSIR_SSINC_MASK;
56 
57 	if (gmac4)
58 		data = data << GMAC4_PTP_SSIR_SSINC_SHIFT;
59 
60 	writel(data, ioaddr + PTP_SSIR);
61 
62 	return data;
63 }
64 
65 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
66 {
67 	int limit;
68 	u32 value;
69 
70 	writel(sec, ioaddr + PTP_STSUR);
71 	writel(nsec, ioaddr + PTP_STNSUR);
72 	/* issue command to initialize the system time value */
73 	value = readl(ioaddr + PTP_TCR);
74 	value |= PTP_TCR_TSINIT;
75 	writel(value, ioaddr + PTP_TCR);
76 
77 	/* wait for present system time initialize to complete */
78 	limit = 10;
79 	while (limit--) {
80 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSINIT))
81 			break;
82 		mdelay(10);
83 	}
84 	if (limit < 0)
85 		return -EBUSY;
86 
87 	return 0;
88 }
89 
90 static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
91 {
92 	u32 value;
93 	int limit;
94 
95 	writel(addend, ioaddr + PTP_TAR);
96 	/* issue command to update the addend value */
97 	value = readl(ioaddr + PTP_TCR);
98 	value |= PTP_TCR_TSADDREG;
99 	writel(value, ioaddr + PTP_TCR);
100 
101 	/* wait for present addend update to complete */
102 	limit = 10;
103 	while (limit--) {
104 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSADDREG))
105 			break;
106 		mdelay(10);
107 	}
108 	if (limit < 0)
109 		return -EBUSY;
110 
111 	return 0;
112 }
113 
114 static int stmmac_adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
115 				 int add_sub, int gmac4)
116 {
117 	u32 value;
118 	int limit;
119 
120 	if (add_sub) {
121 		/* If the new sec value needs to be subtracted with
122 		 * the system time, then MAC_STSUR reg should be
123 		 * programmed with (2^32 – <new_sec_value>)
124 		 */
125 		if (gmac4)
126 			sec = (100000000ULL - sec);
127 
128 		value = readl(ioaddr + PTP_TCR);
129 		if (value & PTP_TCR_TSCTRLSSR)
130 			nsec = (PTP_DIGITAL_ROLLOVER_MODE - nsec);
131 		else
132 			nsec = (PTP_BINARY_ROLLOVER_MODE - nsec);
133 	}
134 
135 	writel(sec, ioaddr + PTP_STSUR);
136 	value = (add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec;
137 	writel(value, ioaddr + PTP_STNSUR);
138 
139 	/* issue command to initialize the system time value */
140 	value = readl(ioaddr + PTP_TCR);
141 	value |= PTP_TCR_TSUPDT;
142 	writel(value, ioaddr + PTP_TCR);
143 
144 	/* wait for present system time adjust/update to complete */
145 	limit = 10;
146 	while (limit--) {
147 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSUPDT))
148 			break;
149 		mdelay(10);
150 	}
151 	if (limit < 0)
152 		return -EBUSY;
153 
154 	return 0;
155 }
156 
157 static u64 stmmac_get_systime(void __iomem *ioaddr)
158 {
159 	u64 ns;
160 
161 	/* Get the TSSS value */
162 	ns = readl(ioaddr + PTP_STNSR);
163 	/* Get the TSS and convert sec time value to nanosecond */
164 	ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
165 
166 	return ns;
167 }
168 
169 const struct stmmac_hwtimestamp stmmac_ptp = {
170 	.config_hw_tstamping = stmmac_config_hw_tstamping,
171 	.init_systime = stmmac_init_systime,
172 	.config_sub_second_increment = stmmac_config_sub_second_increment,
173 	.config_addend = stmmac_config_addend,
174 	.adjust_systime = stmmac_adjust_systime,
175 	.get_systime = stmmac_get_systime,
176 };
177