xref: /linux/drivers/net/ethernet/qualcomm/emac/emac-sgmii.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
3  */
4 
5 /* Qualcomm Technologies, Inc. EMAC SGMII Controller driver.
6  */
7 
8 #include <linux/interrupt.h>
9 #include <linux/iopoll.h>
10 #include <linux/acpi.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/of_platform.h>
14 #include "emac.h"
15 #include "emac-mac.h"
16 #include "emac-sgmii.h"
17 
18 /* EMAC_SGMII register offsets */
19 #define EMAC_SGMII_PHY_AUTONEG_CFG2		0x0048
20 #define EMAC_SGMII_PHY_SPEED_CFG1		0x0074
21 #define EMAC_SGMII_PHY_IRQ_CMD			0x00ac
22 #define EMAC_SGMII_PHY_INTERRUPT_CLEAR		0x00b0
23 #define EMAC_SGMII_PHY_INTERRUPT_MASK		0x00b4
24 #define EMAC_SGMII_PHY_INTERRUPT_STATUS		0x00b8
25 #define EMAC_SGMII_PHY_RX_CHK_STATUS		0x00d4
26 
27 #define FORCE_AN_TX_CFG				BIT(5)
28 #define FORCE_AN_RX_CFG				BIT(4)
29 #define AN_ENABLE				BIT(0)
30 
31 #define DUPLEX_MODE				BIT(4)
32 #define SPDMODE_1000				BIT(1)
33 #define SPDMODE_100				BIT(0)
34 #define SPDMODE_10				0
35 
36 #define CDR_ALIGN_DET				BIT(6)
37 
38 #define IRQ_GLOBAL_CLEAR			BIT(0)
39 
40 #define DECODE_CODE_ERR				BIT(7)
41 #define DECODE_DISP_ERR				BIT(6)
42 
43 #define SGMII_PHY_IRQ_CLR_WAIT_TIME		10
44 
45 #define SGMII_PHY_INTERRUPT_ERR		(DECODE_CODE_ERR | DECODE_DISP_ERR)
46 #define SGMII_ISR_MASK  		(SGMII_PHY_INTERRUPT_ERR)
47 
48 #define SERDES_START_WAIT_TIMES			100
49 
50 int emac_sgmii_init(struct emac_adapter *adpt)
51 {
52 	if (!(adpt->phy.sgmii_ops && adpt->phy.sgmii_ops->init))
53 		return 0;
54 
55 	return adpt->phy.sgmii_ops->init(adpt);
56 }
57 
58 int emac_sgmii_open(struct emac_adapter *adpt)
59 {
60 	if (!(adpt->phy.sgmii_ops && adpt->phy.sgmii_ops->open))
61 		return 0;
62 
63 	return adpt->phy.sgmii_ops->open(adpt);
64 }
65 
66 void emac_sgmii_close(struct emac_adapter *adpt)
67 {
68 	if (!(adpt->phy.sgmii_ops && adpt->phy.sgmii_ops->close))
69 		return;
70 
71 	adpt->phy.sgmii_ops->close(adpt);
72 }
73 
74 int emac_sgmii_link_change(struct emac_adapter *adpt, bool link_state)
75 {
76 	if (!(adpt->phy.sgmii_ops && adpt->phy.sgmii_ops->link_change))
77 		return 0;
78 
79 	return adpt->phy.sgmii_ops->link_change(adpt, link_state);
80 }
81 
82 void emac_sgmii_reset(struct emac_adapter *adpt)
83 {
84 	if (!(adpt->phy.sgmii_ops && adpt->phy.sgmii_ops->reset))
85 		return;
86 
87 	adpt->phy.sgmii_ops->reset(adpt);
88 }
89 
90 /* Initialize the SGMII link between the internal and external PHYs. */
91 static void emac_sgmii_link_init(struct emac_adapter *adpt)
92 {
93 	struct emac_sgmii *phy = &adpt->phy;
94 	u32 val;
95 
96 	/* Always use autonegotiation. It works no matter how the external
97 	 * PHY is configured.
98 	 */
99 	val = readl(phy->base + EMAC_SGMII_PHY_AUTONEG_CFG2);
100 	val &= ~(FORCE_AN_RX_CFG | FORCE_AN_TX_CFG);
101 	val |= AN_ENABLE;
102 	writel(val, phy->base + EMAC_SGMII_PHY_AUTONEG_CFG2);
103 }
104 
105 static int emac_sgmii_irq_clear(struct emac_adapter *adpt, u8 irq_bits)
106 {
107 	struct emac_sgmii *phy = &adpt->phy;
108 	u8 status;
109 
110 	writel_relaxed(irq_bits, phy->base + EMAC_SGMII_PHY_INTERRUPT_CLEAR);
111 	writel_relaxed(IRQ_GLOBAL_CLEAR, phy->base + EMAC_SGMII_PHY_IRQ_CMD);
112 	/* Ensure interrupt clear command is written to HW */
113 	wmb();
114 
115 	/* After set the IRQ_GLOBAL_CLEAR bit, the status clearing must
116 	 * be confirmed before clearing the bits in other registers.
117 	 * It takes a few cycles for hw to clear the interrupt status.
118 	 */
119 	if (readl_poll_timeout_atomic(phy->base +
120 				      EMAC_SGMII_PHY_INTERRUPT_STATUS,
121 				      status, !(status & irq_bits), 1,
122 				      SGMII_PHY_IRQ_CLR_WAIT_TIME)) {
123 		net_err_ratelimited("%s: failed to clear SGMII irq: status:0x%x bits:0x%x\n",
124 				    adpt->netdev->name, status, irq_bits);
125 		return -EIO;
126 	}
127 
128 	/* Finalize clearing procedure */
129 	writel_relaxed(0, phy->base + EMAC_SGMII_PHY_IRQ_CMD);
130 	writel_relaxed(0, phy->base + EMAC_SGMII_PHY_INTERRUPT_CLEAR);
131 
132 	/* Ensure that clearing procedure finalization is written to HW */
133 	wmb();
134 
135 	return 0;
136 }
137 
138 /* The number of decode errors that triggers a reset */
139 #define DECODE_ERROR_LIMIT	2
140 
141 static irqreturn_t emac_sgmii_interrupt(int irq, void *data)
142 {
143 	struct emac_adapter *adpt = data;
144 	struct emac_sgmii *phy = &adpt->phy;
145 	u8 status;
146 
147 	status = readl(phy->base + EMAC_SGMII_PHY_INTERRUPT_STATUS);
148 	status &= SGMII_ISR_MASK;
149 	if (!status)
150 		return IRQ_HANDLED;
151 
152 	/* If we get a decoding error and CDR is not locked, then try
153 	 * resetting the internal PHY.  The internal PHY uses an embedded
154 	 * clock with Clock and Data Recovery (CDR) to recover the
155 	 * clock and data.
156 	 */
157 	if (status & SGMII_PHY_INTERRUPT_ERR) {
158 		int count;
159 
160 		/* The SGMII is capable of recovering from some decode
161 		 * errors automatically.  However, if we get multiple
162 		 * decode errors in a row, then assume that something
163 		 * is wrong and reset the interface.
164 		 */
165 		count = atomic_inc_return(&phy->decode_error_count);
166 		if (count == DECODE_ERROR_LIMIT) {
167 			schedule_work(&adpt->work_thread);
168 			atomic_set(&phy->decode_error_count, 0);
169 		}
170 	} else {
171 		/* We only care about consecutive decode errors. */
172 		atomic_set(&phy->decode_error_count, 0);
173 	}
174 
175 	if (emac_sgmii_irq_clear(adpt, status))
176 		schedule_work(&adpt->work_thread);
177 
178 	return IRQ_HANDLED;
179 }
180 
181 static void emac_sgmii_reset_prepare(struct emac_adapter *adpt)
182 {
183 	struct emac_sgmii *phy = &adpt->phy;
184 	u32 val;
185 
186 	/* Reset PHY */
187 	val = readl(phy->base + EMAC_EMAC_WRAPPER_CSR2);
188 	writel(((val & ~PHY_RESET) | PHY_RESET), phy->base +
189 	       EMAC_EMAC_WRAPPER_CSR2);
190 	/* Ensure phy-reset command is written to HW before the release cmd */
191 	msleep(50);
192 	val = readl(phy->base + EMAC_EMAC_WRAPPER_CSR2);
193 	writel((val & ~PHY_RESET), phy->base + EMAC_EMAC_WRAPPER_CSR2);
194 	/* Ensure phy-reset release command is written to HW before initializing
195 	 * SGMII
196 	 */
197 	msleep(50);
198 }
199 
200 static void emac_sgmii_common_reset(struct emac_adapter *adpt)
201 {
202 	int ret;
203 
204 	emac_sgmii_reset_prepare(adpt);
205 	emac_sgmii_link_init(adpt);
206 
207 	ret = emac_sgmii_init(adpt);
208 	if (ret)
209 		netdev_err(adpt->netdev,
210 			   "could not reinitialize internal PHY (error=%i)\n",
211 			   ret);
212 }
213 
214 static int emac_sgmii_common_open(struct emac_adapter *adpt)
215 {
216 	struct emac_sgmii *sgmii = &adpt->phy;
217 	int ret;
218 
219 	if (sgmii->irq) {
220 		/* Make sure interrupts are cleared and disabled first */
221 		ret = emac_sgmii_irq_clear(adpt, 0xff);
222 		if (ret)
223 			return ret;
224 		writel(0, sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
225 
226 		ret = request_irq(sgmii->irq, emac_sgmii_interrupt, 0,
227 				  "emac-sgmii", adpt);
228 		if (ret) {
229 			netdev_err(adpt->netdev,
230 				   "could not register handler for internal PHY\n");
231 			return ret;
232 		}
233 	}
234 
235 	return 0;
236 }
237 
238 static void emac_sgmii_common_close(struct emac_adapter *adpt)
239 {
240 	struct emac_sgmii *sgmii = &adpt->phy;
241 
242 	/* Make sure interrupts are disabled */
243 	writel(0, sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
244 	free_irq(sgmii->irq, adpt);
245 }
246 
247 /* The error interrupts are only valid after the link is up */
248 static int emac_sgmii_common_link_change(struct emac_adapter *adpt, bool linkup)
249 {
250 	struct emac_sgmii *sgmii = &adpt->phy;
251 	int ret;
252 
253 	if (linkup) {
254 		/* Clear and enable interrupts */
255 		ret = emac_sgmii_irq_clear(adpt, 0xff);
256 		if (ret)
257 			return ret;
258 
259 		writel(SGMII_ISR_MASK,
260 		       sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
261 	} else {
262 		/* Disable interrupts */
263 		writel(0, sgmii->base + EMAC_SGMII_PHY_INTERRUPT_MASK);
264 		synchronize_irq(sgmii->irq);
265 	}
266 
267 	return 0;
268 }
269 
270 static struct sgmii_ops fsm9900_ops = {
271 	.init = emac_sgmii_init_fsm9900,
272 	.open = emac_sgmii_common_open,
273 	.close = emac_sgmii_common_close,
274 	.link_change = emac_sgmii_common_link_change,
275 	.reset = emac_sgmii_common_reset,
276 };
277 
278 static struct sgmii_ops qdf2432_ops = {
279 	.init = emac_sgmii_init_qdf2432,
280 	.open = emac_sgmii_common_open,
281 	.close = emac_sgmii_common_close,
282 	.link_change = emac_sgmii_common_link_change,
283 	.reset = emac_sgmii_common_reset,
284 };
285 
286 #ifdef CONFIG_ACPI
287 static struct sgmii_ops qdf2400_ops = {
288 	.init = emac_sgmii_init_qdf2400,
289 	.open = emac_sgmii_common_open,
290 	.close = emac_sgmii_common_close,
291 	.link_change = emac_sgmii_common_link_change,
292 	.reset = emac_sgmii_common_reset,
293 };
294 #endif
295 
296 struct emac_match_data {
297 	struct sgmii_ops **sgmii_ops;
298 	struct device *target_device;
299 };
300 
301 static int emac_sgmii_acpi_match(struct device *dev, void *data)
302 {
303 #ifdef CONFIG_ACPI
304 	static const struct acpi_device_id match_table[] = {
305 		{
306 			.id = "QCOM8071",
307 		},
308 		{}
309 	};
310 	const struct acpi_device_id *id = acpi_match_device(match_table, dev);
311 	struct emac_match_data *match_data = data;
312 
313 	if (id) {
314 		acpi_handle handle = ACPI_HANDLE(dev);
315 		unsigned long long hrv;
316 		acpi_status status;
317 
318 		status = acpi_evaluate_integer(handle, "_HRV", NULL, &hrv);
319 		if (status) {
320 			if (status == AE_NOT_FOUND)
321 				/* Older versions of the QDF2432 ACPI tables do
322 				 * not have an _HRV property.
323 				 */
324 				hrv = 1;
325 			else
326 				/* Something is wrong with the tables */
327 				return 0;
328 		}
329 
330 		switch (hrv) {
331 		case 1:
332 			*match_data->sgmii_ops = &qdf2432_ops;
333 			match_data->target_device = dev;
334 			return 1;
335 		case 2:
336 			*match_data->sgmii_ops = &qdf2400_ops;
337 			match_data->target_device = dev;
338 			return 1;
339 		}
340 	}
341 #endif
342 
343 	return 0;
344 }
345 
346 static const struct of_device_id emac_sgmii_dt_match[] = {
347 	{
348 		.compatible = "qcom,fsm9900-emac-sgmii",
349 		.data = &fsm9900_ops,
350 	},
351 	{
352 		.compatible = "qcom,qdf2432-emac-sgmii",
353 		.data = &qdf2432_ops,
354 	},
355 	{}
356 };
357 
358 int emac_sgmii_config(struct platform_device *pdev, struct emac_adapter *adpt)
359 {
360 	struct platform_device *sgmii_pdev = NULL;
361 	struct emac_sgmii *phy = &adpt->phy;
362 	struct resource *res;
363 	int ret;
364 
365 	if (has_acpi_companion(&pdev->dev)) {
366 		struct emac_match_data match_data = {
367 			.sgmii_ops = &phy->sgmii_ops,
368 			.target_device = NULL,
369 		};
370 		struct device *dev;
371 
372 		device_for_each_child(&pdev->dev, &match_data, emac_sgmii_acpi_match);
373 		dev = match_data.target_device;
374 
375 		if (!dev) {
376 			dev_warn(&pdev->dev, "cannot find internal phy node\n");
377 			return 0;
378 		}
379 
380 		get_device(dev);
381 		sgmii_pdev = to_platform_device(dev);
382 	} else {
383 		const struct of_device_id *match;
384 		struct device_node *np;
385 
386 		np = of_parse_phandle(pdev->dev.of_node, "internal-phy", 0);
387 		if (!np) {
388 			dev_err(&pdev->dev, "missing internal-phy property\n");
389 			return -ENODEV;
390 		}
391 
392 		sgmii_pdev = of_find_device_by_node(np);
393 		of_node_put(np);
394 		if (!sgmii_pdev) {
395 			dev_err(&pdev->dev, "invalid internal-phy property\n");
396 			return -ENODEV;
397 		}
398 
399 		match = of_match_device(emac_sgmii_dt_match, &sgmii_pdev->dev);
400 		if (!match) {
401 			dev_err(&pdev->dev, "unrecognized internal phy node\n");
402 			ret = -ENODEV;
403 			goto error_put_device;
404 		}
405 
406 		phy->sgmii_ops = (struct sgmii_ops *)match->data;
407 	}
408 
409 	/* Base address is the first address */
410 	res = platform_get_resource(sgmii_pdev, IORESOURCE_MEM, 0);
411 	if (!res) {
412 		ret = -EINVAL;
413 		goto error_put_device;
414 	}
415 
416 	phy->base = ioremap(res->start, resource_size(res));
417 	if (!phy->base) {
418 		ret = -ENOMEM;
419 		goto error_put_device;
420 	}
421 
422 	/* v2 SGMII has a per-lane digital digital, so parse it if it exists */
423 	res = platform_get_resource(sgmii_pdev, IORESOURCE_MEM, 1);
424 	if (res) {
425 		phy->digital = ioremap(res->start, resource_size(res));
426 		if (!phy->digital) {
427 			ret = -ENOMEM;
428 			goto error_unmap_base;
429 		}
430 	}
431 
432 	ret = emac_sgmii_init(adpt);
433 	if (ret)
434 		goto error;
435 
436 	emac_sgmii_link_init(adpt);
437 
438 	ret = platform_get_irq(sgmii_pdev, 0);
439 	if (ret > 0)
440 		phy->irq = ret;
441 
442 	/* We've remapped the addresses, so we don't need the device any
443 	 * more.  of_find_device_by_node() says we should release it.
444 	 */
445 	put_device(&sgmii_pdev->dev);
446 
447 	return 0;
448 
449 error:
450 	if (phy->digital)
451 		iounmap(phy->digital);
452 error_unmap_base:
453 	iounmap(phy->base);
454 error_put_device:
455 	put_device(&sgmii_pdev->dev);
456 
457 	return ret;
458 }
459