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
17static const struct rcar_gen4_ptp_reg_offset gen4_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
29static 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(dividend: addend * scaled_ppm_to_ppb(ppm: 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 */
47static 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
57static 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(lock: &ptp_priv->lock, flags);
66
67 return 0;
68}
69
70/* Caller must hold the lock */
71static 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
86static 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(lock: &ptp_priv->lock, flags);
95
96 return 0;
97}
98
99static 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: &ts);
108 now = ktime_to_ns(kt: timespec64_to_ktime(ts));
109 ts = ns_to_timespec64(nsec: now + delta);
110 _rcar_gen4_ptp_settime(ptp, ts: &ts);
111 spin_unlock_irqrestore(lock: &ptp_priv->lock, flags);
112
113 return 0;
114}
115
116static int rcar_gen4_ptp_enable(struct ptp_clock_info *ptp,
117 struct ptp_clock_request *rq, int on)
118{
119 return -EOPNOTSUPP;
120}
121
122static 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
133static int rcar_gen4_ptp_set_offs(struct rcar_gen4_ptp_private *ptp_priv,
134 enum rcar_gen4_ptp_reg_layout layout)
135{
136 if (layout != RCAR_GEN4_PTP_REG_LAYOUT)
137 return -EINVAL;
138
139 ptp_priv->offs = &gen4_offs;
140
141 return 0;
142}
143
144static s64 rcar_gen4_ptp_rate_to_increment(u32 rate)
145{
146 /* Timer increment in ns.
147 * bit[31:27] - integer
148 * bit[26:0] - decimal
149 * increment[ns] = perid[ns] * 2^27 => (1ns * 2^27) / rate[hz]
150 */
151 return div_s64(dividend: 1000000000LL << 27, divisor: rate);
152}
153
154int rcar_gen4_ptp_register(struct rcar_gen4_ptp_private *ptp_priv,
155 enum rcar_gen4_ptp_reg_layout layout, u32 rate)
156{
157 int ret;
158
159 if (ptp_priv->initialized)
160 return 0;
161
162 spin_lock_init(&ptp_priv->lock);
163
164 ret = rcar_gen4_ptp_set_offs(ptp_priv, layout);
165 if (ret)
166 return ret;
167
168 ptp_priv->default_addend = rcar_gen4_ptp_rate_to_increment(rate);
169 iowrite32(ptp_priv->default_addend, ptp_priv->addr + ptp_priv->offs->increment);
170 ptp_priv->clock = ptp_clock_register(info: &ptp_priv->info, NULL);
171 if (IS_ERR(ptr: ptp_priv->clock))
172 return PTR_ERR(ptr: ptp_priv->clock);
173
174 iowrite32(0x01, ptp_priv->addr + ptp_priv->offs->enable);
175 ptp_priv->initialized = true;
176
177 return 0;
178}
179EXPORT_SYMBOL_GPL(rcar_gen4_ptp_register);
180
181int rcar_gen4_ptp_unregister(struct rcar_gen4_ptp_private *ptp_priv)
182{
183 iowrite32(1, ptp_priv->addr + ptp_priv->offs->disable);
184
185 return ptp_clock_unregister(ptp: ptp_priv->clock);
186}
187EXPORT_SYMBOL_GPL(rcar_gen4_ptp_unregister);
188
189struct rcar_gen4_ptp_private *rcar_gen4_ptp_alloc(struct platform_device *pdev)
190{
191 struct rcar_gen4_ptp_private *ptp;
192
193 ptp = devm_kzalloc(dev: &pdev->dev, size: sizeof(*ptp), GFP_KERNEL);
194 if (!ptp)
195 return NULL;
196
197 ptp->info = rcar_gen4_ptp_info;
198
199 return ptp;
200}
201EXPORT_SYMBOL_GPL(rcar_gen4_ptp_alloc);
202
203MODULE_AUTHOR("Yoshihiro Shimoda");
204MODULE_DESCRIPTION("Renesas R-Car Gen4 gPTP driver");
205MODULE_LICENSE("GPL");
206

source code of linux/drivers/net/ethernet/renesas/rcar_gen4_ptp.c