xref: /linux/drivers/net/ethernet/renesas/rcar_gen4_ptp.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Renesas R-Car Gen4 gPTP device driver
3  *
4  * Copyright (C) 2022 Renesas Electronics Corporation
5  */
6 
7 #include <linux/err.h>
8 #include <linux/etherdevice.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/slab.h>
13 
14 #include "rcar_gen4_ptp.h"
15 #define ptp_to_priv(ptp)	container_of(ptp, struct rcar_gen4_ptp_private, info)
16 
17 static const struct rcar_gen4_ptp_reg_offset s4_offs = {
18 	.enable = PTPTMEC,
19 	.disable = PTPTMDC,
20 	.increment = PTPTIVC0,
21 	.config_t0 = PTPTOVC00,
22 	.config_t1 = PTPTOVC10,
23 	.config_t2 = PTPTOVC20,
24 	.monitor_t0 = PTPGPTPTM00,
25 	.monitor_t1 = PTPGPTPTM10,
26 	.monitor_t2 = PTPGPTPTM20,
27 };
28 
29 static int rcar_gen4_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
30 {
31 	struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
32 	bool neg_adj = scaled_ppm < 0 ? true : false;
33 	s64 addend = ptp_priv->default_addend;
34 	s64 diff;
35 
36 	if (neg_adj)
37 		scaled_ppm = -scaled_ppm;
38 	diff = div_s64(addend * scaled_ppm_to_ppb(scaled_ppm), NSEC_PER_SEC);
39 	addend = neg_adj ? addend - diff : addend + diff;
40 
41 	iowrite32(addend, ptp_priv->addr + ptp_priv->offs->increment);
42 
43 	return 0;
44 }
45 
46 /* Caller must hold the lock */
47 static void _rcar_gen4_ptp_gettime(struct ptp_clock_info *ptp,
48 				   struct timespec64 *ts)
49 {
50 	struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
51 
52 	ts->tv_nsec = ioread32(ptp_priv->addr + ptp_priv->offs->monitor_t0);
53 	ts->tv_sec = ioread32(ptp_priv->addr + ptp_priv->offs->monitor_t1) |
54 		     ((s64)ioread32(ptp_priv->addr + ptp_priv->offs->monitor_t2) << 32);
55 }
56 
57 static int rcar_gen4_ptp_gettime(struct ptp_clock_info *ptp,
58 				 struct timespec64 *ts)
59 {
60 	struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
61 	unsigned long flags;
62 
63 	spin_lock_irqsave(&ptp_priv->lock, flags);
64 	_rcar_gen4_ptp_gettime(ptp, ts);
65 	spin_unlock_irqrestore(&ptp_priv->lock, flags);
66 
67 	return 0;
68 }
69 
70 /* Caller must hold the lock */
71 static void _rcar_gen4_ptp_settime(struct ptp_clock_info *ptp,
72 				   const struct timespec64 *ts)
73 {
74 	struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
75 
76 	iowrite32(1, ptp_priv->addr + ptp_priv->offs->disable);
77 	iowrite32(0, ptp_priv->addr + ptp_priv->offs->config_t2);
78 	iowrite32(0, ptp_priv->addr + ptp_priv->offs->config_t1);
79 	iowrite32(0, ptp_priv->addr + ptp_priv->offs->config_t0);
80 	iowrite32(1, ptp_priv->addr + ptp_priv->offs->enable);
81 	iowrite32(ts->tv_sec >> 32, ptp_priv->addr + ptp_priv->offs->config_t2);
82 	iowrite32(ts->tv_sec, ptp_priv->addr + ptp_priv->offs->config_t1);
83 	iowrite32(ts->tv_nsec, ptp_priv->addr + ptp_priv->offs->config_t0);
84 }
85 
86 static int rcar_gen4_ptp_settime(struct ptp_clock_info *ptp,
87 				 const struct timespec64 *ts)
88 {
89 	struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
90 	unsigned long flags;
91 
92 	spin_lock_irqsave(&ptp_priv->lock, flags);
93 	_rcar_gen4_ptp_settime(ptp, ts);
94 	spin_unlock_irqrestore(&ptp_priv->lock, flags);
95 
96 	return 0;
97 }
98 
99 static int rcar_gen4_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
100 {
101 	struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
102 	struct timespec64 ts;
103 	unsigned long flags;
104 	s64 now;
105 
106 	spin_lock_irqsave(&ptp_priv->lock, flags);
107 	_rcar_gen4_ptp_gettime(ptp, &ts);
108 	now = ktime_to_ns(timespec64_to_ktime(ts));
109 	ts = ns_to_timespec64(now + delta);
110 	_rcar_gen4_ptp_settime(ptp, &ts);
111 	spin_unlock_irqrestore(&ptp_priv->lock, flags);
112 
113 	return 0;
114 }
115 
116 static int rcar_gen4_ptp_enable(struct ptp_clock_info *ptp,
117 				struct ptp_clock_request *rq, int on)
118 {
119 	return -EOPNOTSUPP;
120 }
121 
122 static struct ptp_clock_info rcar_gen4_ptp_info = {
123 	.owner = THIS_MODULE,
124 	.name = "rcar_gen4_ptp",
125 	.max_adj = 50000000,
126 	.adjfine = rcar_gen4_ptp_adjfine,
127 	.adjtime = rcar_gen4_ptp_adjtime,
128 	.gettime64 = rcar_gen4_ptp_gettime,
129 	.settime64 = rcar_gen4_ptp_settime,
130 	.enable = rcar_gen4_ptp_enable,
131 };
132 
133 static void rcar_gen4_ptp_set_offs(struct rcar_gen4_ptp_private *ptp_priv,
134 				   enum rcar_gen4_ptp_reg_layout layout)
135 {
136 	WARN_ON(layout != RCAR_GEN4_PTP_REG_LAYOUT_S4);
137 
138 	ptp_priv->offs = &s4_offs;
139 }
140 
141 int rcar_gen4_ptp_register(struct rcar_gen4_ptp_private *ptp_priv,
142 			   enum rcar_gen4_ptp_reg_layout layout, u32 clock)
143 {
144 	if (ptp_priv->initialized)
145 		return 0;
146 
147 	spin_lock_init(&ptp_priv->lock);
148 
149 	rcar_gen4_ptp_set_offs(ptp_priv, layout);
150 
151 	ptp_priv->default_addend = clock;
152 	iowrite32(ptp_priv->default_addend, ptp_priv->addr + ptp_priv->offs->increment);
153 	ptp_priv->clock = ptp_clock_register(&ptp_priv->info, NULL);
154 	if (IS_ERR(ptp_priv->clock))
155 		return PTR_ERR(ptp_priv->clock);
156 
157 	iowrite32(0x01, ptp_priv->addr + ptp_priv->offs->enable);
158 	ptp_priv->initialized = true;
159 
160 	return 0;
161 }
162 
163 int rcar_gen4_ptp_unregister(struct rcar_gen4_ptp_private *ptp_priv)
164 {
165 	iowrite32(1, ptp_priv->addr + ptp_priv->offs->disable);
166 
167 	return ptp_clock_unregister(ptp_priv->clock);
168 }
169 
170 struct rcar_gen4_ptp_private *rcar_gen4_ptp_alloc(struct platform_device *pdev)
171 {
172 	struct rcar_gen4_ptp_private *ptp;
173 
174 	ptp = devm_kzalloc(&pdev->dev, sizeof(*ptp), GFP_KERNEL);
175 	if (!ptp)
176 		return NULL;
177 
178 	ptp->info = rcar_gen4_ptp_info;
179 
180 	return ptp;
181 }
182