1 // SPDX-License-Identifier: GPL-2.0
2 /* Marvell PTP driver
3  *
4  * Copyright (C) 2020 Marvell International Ltd.
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/device.h>
9 #include <linux/module.h>
10 #include <linux/pci.h>
11 
12 #include "ptp.h"
13 #include "mbox.h"
14 #include "rvu.h"
15 
16 #define DRV_NAME				"Marvell PTP Driver"
17 
18 #define PCI_DEVID_OCTEONTX2_PTP			0xA00C
19 #define PCI_SUBSYS_DEVID_OCTX2_98xx_PTP		0xB100
20 #define PCI_SUBSYS_DEVID_OCTX2_96XX_PTP		0xB200
21 #define PCI_SUBSYS_DEVID_OCTX2_95XX_PTP		0xB300
22 #define PCI_SUBSYS_DEVID_OCTX2_LOKI_PTP		0xB400
23 #define PCI_SUBSYS_DEVID_OCTX2_95MM_PTP		0xB500
24 #define PCI_SUBSYS_DEVID_CN10K_A_PTP		0xB900
25 #define PCI_SUBSYS_DEVID_CNF10K_A_PTP		0xBA00
26 #define PCI_SUBSYS_DEVID_CNF10K_B_PTP		0xBC00
27 #define PCI_DEVID_OCTEONTX2_RST			0xA085
28 
29 #define PCI_PTP_BAR_NO				0
30 #define PCI_RST_BAR_NO				0
31 
32 #define PTP_CLOCK_CFG				0xF00ULL
33 #define PTP_CLOCK_CFG_PTP_EN			BIT_ULL(0)
34 #define PTP_CLOCK_LO				0xF08ULL
35 #define PTP_CLOCK_HI				0xF10ULL
36 #define PTP_CLOCK_COMP				0xF18ULL
37 
38 #define RST_BOOT				0x1600ULL
39 #define RST_MUL_BITS				GENMASK_ULL(38, 33)
40 #define CLOCK_BASE_RATE				50000000ULL
41 
42 static u64 get_clock_rate(void)
43 {
44 	u64 cfg, ret = CLOCK_BASE_RATE * 16;
45 	struct pci_dev *pdev;
46 	void __iomem *base;
47 
48 	/* To get the input clock frequency with which PTP co-processor
49 	 * block is running the base frequency(50 MHz) needs to be multiplied
50 	 * with multiplier bits present in RST_BOOT register of RESET block.
51 	 * Hence below code gets the multiplier bits from the RESET PCI
52 	 * device present in the system.
53 	 */
54 	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
55 			      PCI_DEVID_OCTEONTX2_RST, NULL);
56 	if (!pdev)
57 		goto error;
58 
59 	base = pci_ioremap_bar(pdev, PCI_RST_BAR_NO);
60 	if (!base)
61 		goto error_put_pdev;
62 
63 	cfg = readq(base + RST_BOOT);
64 	ret = CLOCK_BASE_RATE * FIELD_GET(RST_MUL_BITS, cfg);
65 
66 	iounmap(base);
67 
68 error_put_pdev:
69 	pci_dev_put(pdev);
70 
71 error:
72 	return ret;
73 }
74 
75 struct ptp *ptp_get(void)
76 {
77 	struct pci_dev *pdev;
78 	struct ptp *ptp;
79 
80 	/* If the PTP pci device is found on the system and ptp
81 	 * driver is bound to it then the PTP pci device is returned
82 	 * to the caller(rvu driver).
83 	 */
84 	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
85 			      PCI_DEVID_OCTEONTX2_PTP, NULL);
86 	if (!pdev)
87 		return ERR_PTR(-ENODEV);
88 
89 	ptp = pci_get_drvdata(pdev);
90 	if (!ptp)
91 		ptp = ERR_PTR(-EPROBE_DEFER);
92 	if (IS_ERR(ptp))
93 		pci_dev_put(pdev);
94 
95 	return ptp;
96 }
97 
98 void ptp_put(struct ptp *ptp)
99 {
100 	if (!ptp)
101 		return;
102 
103 	pci_dev_put(ptp->pdev);
104 }
105 
106 static int ptp_adjfine(struct ptp *ptp, long scaled_ppm)
107 {
108 	bool neg_adj = false;
109 	u64 comp;
110 	u64 adj;
111 	s64 ppb;
112 
113 	if (scaled_ppm < 0) {
114 		neg_adj = true;
115 		scaled_ppm = -scaled_ppm;
116 	}
117 
118 	/* The hardware adds the clock compensation value to the PTP clock
119 	 * on every coprocessor clock cycle. Typical convention is that it
120 	 * represent number of nanosecond betwen each cycle. In this
121 	 * convention compensation value is in 64 bit fixed-point
122 	 * representation where upper 32 bits are number of nanoseconds
123 	 * and lower is fractions of nanosecond.
124 	 * The scaled_ppm represent the ratio in "parts per million" by which
125 	 * the compensation value should be corrected.
126 	 * To calculate new compenstation value we use 64bit fixed point
127 	 * arithmetic on following formula
128 	 * comp = tbase + tbase * scaled_ppm / (1M * 2^16)
129 	 * where tbase is the basic compensation value calculated
130 	 * initialy in the probe function.
131 	 */
132 	comp = ((u64)1000000000ull << 32) / ptp->clock_rate;
133 	/* convert scaled_ppm to ppb */
134 	ppb = 1 + scaled_ppm;
135 	ppb *= 125;
136 	ppb >>= 13;
137 	adj = comp * ppb;
138 	adj = div_u64(adj, 1000000000ull);
139 	comp = neg_adj ? comp - adj : comp + adj;
140 
141 	writeq(comp, ptp->reg_base + PTP_CLOCK_COMP);
142 
143 	return 0;
144 }
145 
146 static int ptp_get_clock(struct ptp *ptp, u64 *clk)
147 {
148 	/* Return the current PTP clock */
149 	*clk = readq(ptp->reg_base + PTP_CLOCK_HI);
150 
151 	return 0;
152 }
153 
154 static int ptp_probe(struct pci_dev *pdev,
155 		     const struct pci_device_id *ent)
156 {
157 	struct device *dev = &pdev->dev;
158 	struct ptp *ptp;
159 	u64 clock_comp;
160 	u64 clock_cfg;
161 	int err;
162 
163 	ptp = devm_kzalloc(dev, sizeof(*ptp), GFP_KERNEL);
164 	if (!ptp) {
165 		err = -ENOMEM;
166 		goto error;
167 	}
168 
169 	ptp->pdev = pdev;
170 
171 	err = pcim_enable_device(pdev);
172 	if (err)
173 		goto error_free;
174 
175 	err = pcim_iomap_regions(pdev, 1 << PCI_PTP_BAR_NO, pci_name(pdev));
176 	if (err)
177 		goto error_free;
178 
179 	ptp->reg_base = pcim_iomap_table(pdev)[PCI_PTP_BAR_NO];
180 
181 	ptp->clock_rate = get_clock_rate();
182 
183 	/* Enable PTP clock */
184 	clock_cfg = readq(ptp->reg_base + PTP_CLOCK_CFG);
185 	clock_cfg |= PTP_CLOCK_CFG_PTP_EN;
186 	writeq(clock_cfg, ptp->reg_base + PTP_CLOCK_CFG);
187 
188 	clock_comp = ((u64)1000000000ull << 32) / ptp->clock_rate;
189 	/* Initial compensation value to start the nanosecs counter */
190 	writeq(clock_comp, ptp->reg_base + PTP_CLOCK_COMP);
191 
192 	pci_set_drvdata(pdev, ptp);
193 
194 	return 0;
195 
196 error_free:
197 	devm_kfree(dev, ptp);
198 
199 error:
200 	/* For `ptp_get()` we need to differentiate between the case
201 	 * when the core has not tried to probe this device and the case when
202 	 * the probe failed.  In the later case we pretend that the
203 	 * initialization was successful and keep the error in
204 	 * `dev->driver_data`.
205 	 */
206 	pci_set_drvdata(pdev, ERR_PTR(err));
207 	return 0;
208 }
209 
210 static void ptp_remove(struct pci_dev *pdev)
211 {
212 	struct ptp *ptp = pci_get_drvdata(pdev);
213 	u64 clock_cfg;
214 
215 	if (IS_ERR_OR_NULL(ptp))
216 		return;
217 
218 	/* Disable PTP clock */
219 	clock_cfg = readq(ptp->reg_base + PTP_CLOCK_CFG);
220 	clock_cfg &= ~PTP_CLOCK_CFG_PTP_EN;
221 	writeq(clock_cfg, ptp->reg_base + PTP_CLOCK_CFG);
222 }
223 
224 static const struct pci_device_id ptp_id_table[] = {
225 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
226 			 PCI_VENDOR_ID_CAVIUM,
227 			 PCI_SUBSYS_DEVID_OCTX2_98xx_PTP) },
228 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
229 			 PCI_VENDOR_ID_CAVIUM,
230 			 PCI_SUBSYS_DEVID_OCTX2_96XX_PTP) },
231 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
232 			 PCI_VENDOR_ID_CAVIUM,
233 			 PCI_SUBSYS_DEVID_OCTX2_95XX_PTP) },
234 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
235 			 PCI_VENDOR_ID_CAVIUM,
236 			 PCI_SUBSYS_DEVID_OCTX2_LOKI_PTP) },
237 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
238 			 PCI_VENDOR_ID_CAVIUM,
239 			 PCI_SUBSYS_DEVID_OCTX2_95MM_PTP) },
240 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
241 			 PCI_VENDOR_ID_CAVIUM,
242 			 PCI_SUBSYS_DEVID_CN10K_A_PTP) },
243 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
244 			 PCI_VENDOR_ID_CAVIUM,
245 			 PCI_SUBSYS_DEVID_CNF10K_A_PTP) },
246 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_OCTEONTX2_PTP,
247 			 PCI_VENDOR_ID_CAVIUM,
248 			 PCI_SUBSYS_DEVID_CNF10K_B_PTP) },
249 	{ 0, }
250 };
251 
252 struct pci_driver ptp_driver = {
253 	.name = DRV_NAME,
254 	.id_table = ptp_id_table,
255 	.probe = ptp_probe,
256 	.remove = ptp_remove,
257 };
258 
259 int rvu_mbox_handler_ptp_op(struct rvu *rvu, struct ptp_req *req,
260 			    struct ptp_rsp *rsp)
261 {
262 	int err = 0;
263 
264 	/* This function is the PTP mailbox handler invoked when
265 	 * called by AF consumers/netdev drivers via mailbox mechanism.
266 	 * It is used by netdev driver to get the PTP clock and to set
267 	 * frequency adjustments. Since mailbox can be called without
268 	 * notion of whether the driver is bound to ptp device below
269 	 * validation is needed as first step.
270 	 */
271 	if (!rvu->ptp)
272 		return -ENODEV;
273 
274 	switch (req->op) {
275 	case PTP_OP_ADJFINE:
276 		err = ptp_adjfine(rvu->ptp, req->scaled_ppm);
277 		break;
278 	case PTP_OP_GET_CLOCK:
279 		err = ptp_get_clock(rvu->ptp, &rsp->clk);
280 		break;
281 	default:
282 		err = -EINVAL;
283 		break;
284 	}
285 
286 	return err;
287 }
288