1 // SPDX-License-Identifier: GPL-2.0-only
2 /*******************************************************************************
3   Copyright (C) 2013  Vayavya Labs Pvt Ltd
4 
5   This implements all the API for managing HW timestamp & PTP.
6 
7 
8   Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
9   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
10 *******************************************************************************/
11 
12 #include <linux/io.h>
13 #include <linux/delay.h>
14 #include "common.h"
15 #include "stmmac_ptp.h"
16 
17 static void config_hw_tstamping(void __iomem *ioaddr, u32 data)
18 {
19 	writel(data, ioaddr + PTP_TCR);
20 }
21 
22 static void config_sub_second_increment(void __iomem *ioaddr,
23 		u32 ptp_clock, int gmac4, u32 *ssinc)
24 {
25 	u32 value = readl(ioaddr + PTP_TCR);
26 	unsigned long data;
27 	u32 reg_value;
28 
29 	/* For GMAC3.x, 4.x versions, convert the ptp_clock to nano second
30 	 *	formula = (1/ptp_clock) * 1000000000
31 	 * where ptp_clock is 50MHz if fine method is used to update system
32 	 */
33 	if (value & PTP_TCR_TSCFUPDT)
34 		data = (1000000000ULL / 50000000);
35 	else
36 		data = (1000000000ULL / ptp_clock);
37 
38 	/* 0.465ns accuracy */
39 	if (!(value & PTP_TCR_TSCTRLSSR))
40 		data = (data * 1000) / 465;
41 
42 	data &= PTP_SSIR_SSINC_MASK;
43 
44 	reg_value = data;
45 	if (gmac4)
46 		reg_value <<= GMAC4_PTP_SSIR_SSINC_SHIFT;
47 
48 	writel(reg_value, ioaddr + PTP_SSIR);
49 
50 	if (ssinc)
51 		*ssinc = data;
52 }
53 
54 static int 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 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 adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
104 		int add_sub, int gmac4)
105 {
106 	u32 value;
107 	int limit;
108 
109 	if (add_sub) {
110 		/* If the new sec value needs to be subtracted with
111 		 * the system time, then MAC_STSUR reg should be
112 		 * programmed with (2^32 – <new_sec_value>)
113 		 */
114 		if (gmac4)
115 			sec = -sec;
116 
117 		value = readl(ioaddr + PTP_TCR);
118 		if (value & PTP_TCR_TSCTRLSSR)
119 			nsec = (PTP_DIGITAL_ROLLOVER_MODE - nsec);
120 		else
121 			nsec = (PTP_BINARY_ROLLOVER_MODE - nsec);
122 	}
123 
124 	writel(sec, ioaddr + PTP_STSUR);
125 	value = (add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec;
126 	writel(value, ioaddr + PTP_STNSUR);
127 
128 	/* issue command to initialize the system time value */
129 	value = readl(ioaddr + PTP_TCR);
130 	value |= PTP_TCR_TSUPDT;
131 	writel(value, ioaddr + PTP_TCR);
132 
133 	/* wait for present system time adjust/update to complete */
134 	limit = 10;
135 	while (limit--) {
136 		if (!(readl(ioaddr + PTP_TCR) & PTP_TCR_TSUPDT))
137 			break;
138 		mdelay(10);
139 	}
140 	if (limit < 0)
141 		return -EBUSY;
142 
143 	return 0;
144 }
145 
146 static void get_systime(void __iomem *ioaddr, u64 *systime)
147 {
148 	u64 ns;
149 
150 	/* Get the TSSS value */
151 	ns = readl(ioaddr + PTP_STNSR);
152 	/* Get the TSS and convert sec time value to nanosecond */
153 	ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
154 
155 	if (systime)
156 		*systime = ns;
157 }
158 
159 const struct stmmac_hwtimestamp stmmac_ptp = {
160 	.config_hw_tstamping = config_hw_tstamping,
161 	.init_systime = init_systime,
162 	.config_sub_second_increment = config_sub_second_increment,
163 	.config_addend = config_addend,
164 	.adjust_systime = adjust_systime,
165 	.get_systime = get_systime,
166 };
167