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