1 /*
2  * Broadcom GENET MDIO routines
3  *
4  * Copyright (c) 2014 Broadcom Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 
12 #include <linux/types.h>
13 #include <linux/delay.h>
14 #include <linux/wait.h>
15 #include <linux/mii.h>
16 #include <linux/ethtool.h>
17 #include <linux/bitops.h>
18 #include <linux/netdevice.h>
19 #include <linux/platform_device.h>
20 #include <linux/phy.h>
21 #include <linux/phy_fixed.h>
22 #include <linux/brcmphy.h>
23 #include <linux/of.h>
24 #include <linux/of_net.h>
25 #include <linux/of_mdio.h>
26 
27 #include "bcmgenet.h"
28 
29 /* read a value from the MII */
30 static int bcmgenet_mii_read(struct mii_bus *bus, int phy_id, int location)
31 {
32 	int ret;
33 	struct net_device *dev = bus->priv;
34 	struct bcmgenet_priv *priv = netdev_priv(dev);
35 	u32 reg;
36 
37 	bcmgenet_umac_writel(priv, (MDIO_RD | (phy_id << MDIO_PMD_SHIFT) |
38 			     (location << MDIO_REG_SHIFT)), UMAC_MDIO_CMD);
39 	/* Start MDIO transaction*/
40 	reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
41 	reg |= MDIO_START_BUSY;
42 	bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
43 	wait_event_timeout(priv->wq,
44 			   !(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD)
45 			   & MDIO_START_BUSY),
46 			   HZ / 100);
47 	ret = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
48 
49 	if (ret & MDIO_READ_FAIL)
50 		return -EIO;
51 
52 	return ret & 0xffff;
53 }
54 
55 /* write a value to the MII */
56 static int bcmgenet_mii_write(struct mii_bus *bus, int phy_id,
57 			      int location, u16 val)
58 {
59 	struct net_device *dev = bus->priv;
60 	struct bcmgenet_priv *priv = netdev_priv(dev);
61 	u32 reg;
62 
63 	bcmgenet_umac_writel(priv, (MDIO_WR | (phy_id << MDIO_PMD_SHIFT) |
64 			     (location << MDIO_REG_SHIFT) | (0xffff & val)),
65 			     UMAC_MDIO_CMD);
66 	reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
67 	reg |= MDIO_START_BUSY;
68 	bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
69 	wait_event_timeout(priv->wq,
70 			   !(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD) &
71 			   MDIO_START_BUSY),
72 			   HZ / 100);
73 
74 	return 0;
75 }
76 
77 /* setup netdev link state when PHY link status change and
78  * update UMAC and RGMII block when link up
79  */
80 void bcmgenet_mii_setup(struct net_device *dev)
81 {
82 	struct bcmgenet_priv *priv = netdev_priv(dev);
83 	struct phy_device *phydev = priv->phydev;
84 	u32 reg, cmd_bits = 0;
85 	bool status_changed = false;
86 
87 	if (priv->old_link != phydev->link) {
88 		status_changed = true;
89 		priv->old_link = phydev->link;
90 	}
91 
92 	if (phydev->link) {
93 		/* check speed/duplex/pause changes */
94 		if (priv->old_speed != phydev->speed) {
95 			status_changed = true;
96 			priv->old_speed = phydev->speed;
97 		}
98 
99 		if (priv->old_duplex != phydev->duplex) {
100 			status_changed = true;
101 			priv->old_duplex = phydev->duplex;
102 		}
103 
104 		if (priv->old_pause != phydev->pause) {
105 			status_changed = true;
106 			priv->old_pause = phydev->pause;
107 		}
108 
109 		/* done if nothing has changed */
110 		if (!status_changed)
111 			return;
112 
113 		/* speed */
114 		if (phydev->speed == SPEED_1000)
115 			cmd_bits = UMAC_SPEED_1000;
116 		else if (phydev->speed == SPEED_100)
117 			cmd_bits = UMAC_SPEED_100;
118 		else
119 			cmd_bits = UMAC_SPEED_10;
120 		cmd_bits <<= CMD_SPEED_SHIFT;
121 
122 		/* duplex */
123 		if (phydev->duplex != DUPLEX_FULL)
124 			cmd_bits |= CMD_HD_EN;
125 
126 		/* pause capability */
127 		if (!phydev->pause)
128 			cmd_bits |= CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE;
129 
130 		/*
131 		 * Program UMAC and RGMII block based on established
132 		 * link speed, duplex, and pause. The speed set in
133 		 * umac->cmd tell RGMII block which clock to use for
134 		 * transmit -- 25MHz(100Mbps) or 125MHz(1Gbps).
135 		 * Receive clock is provided by the PHY.
136 		 */
137 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
138 		reg &= ~OOB_DISABLE;
139 		reg |= RGMII_LINK;
140 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
141 
142 		reg = bcmgenet_umac_readl(priv, UMAC_CMD);
143 		reg &= ~((CMD_SPEED_MASK << CMD_SPEED_SHIFT) |
144 			       CMD_HD_EN |
145 			       CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE);
146 		reg |= cmd_bits;
147 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
148 	} else {
149 		/* done if nothing has changed */
150 		if (!status_changed)
151 			return;
152 
153 		/* needed for MoCA fixed PHY to reflect correct link status */
154 		netif_carrier_off(dev);
155 	}
156 
157 	phy_print_status(phydev);
158 }
159 
160 void bcmgenet_mii_reset(struct net_device *dev)
161 {
162 	struct bcmgenet_priv *priv = netdev_priv(dev);
163 
164 	if (priv->phydev) {
165 		phy_init_hw(priv->phydev);
166 		phy_start_aneg(priv->phydev);
167 	}
168 }
169 
170 static void bcmgenet_ephy_power_up(struct net_device *dev)
171 {
172 	struct bcmgenet_priv *priv = netdev_priv(dev);
173 	u32 reg = 0;
174 
175 	/* EXT_GPHY_CTRL is only valid for GENETv4 and onward */
176 	if (!GENET_IS_V4(priv))
177 		return;
178 
179 	reg = bcmgenet_ext_readl(priv, EXT_GPHY_CTRL);
180 	reg &= ~(EXT_CFG_IDDQ_BIAS | EXT_CFG_PWR_DOWN);
181 	reg |= EXT_GPHY_RESET;
182 	bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
183 	mdelay(2);
184 
185 	reg &= ~EXT_GPHY_RESET;
186 	bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
187 	udelay(20);
188 }
189 
190 static void bcmgenet_internal_phy_setup(struct net_device *dev)
191 {
192 	struct bcmgenet_priv *priv = netdev_priv(dev);
193 	u32 reg;
194 
195 	/* Power up EPHY */
196 	bcmgenet_ephy_power_up(dev);
197 	/* enable APD */
198 	reg = bcmgenet_ext_readl(priv, EXT_EXT_PWR_MGMT);
199 	reg |= EXT_PWR_DN_EN_LD;
200 	bcmgenet_ext_writel(priv, reg, EXT_EXT_PWR_MGMT);
201 	bcmgenet_mii_reset(dev);
202 }
203 
204 static void bcmgenet_moca_phy_setup(struct bcmgenet_priv *priv)
205 {
206 	u32 reg;
207 
208 	/* Speed settings are set in bcmgenet_mii_setup() */
209 	reg = bcmgenet_sys_readl(priv, SYS_PORT_CTRL);
210 	reg |= LED_ACT_SOURCE_MAC;
211 	bcmgenet_sys_writel(priv, reg, SYS_PORT_CTRL);
212 }
213 
214 int bcmgenet_mii_config(struct net_device *dev, bool init)
215 {
216 	struct bcmgenet_priv *priv = netdev_priv(dev);
217 	struct phy_device *phydev = priv->phydev;
218 	struct device *kdev = &priv->pdev->dev;
219 	const char *phy_name = NULL;
220 	u32 id_mode_dis = 0;
221 	u32 port_ctrl;
222 	u32 reg;
223 
224 	priv->ext_phy = !phy_is_internal(priv->phydev) &&
225 			(priv->phy_interface != PHY_INTERFACE_MODE_MOCA);
226 
227 	if (phy_is_internal(priv->phydev))
228 		priv->phy_interface = PHY_INTERFACE_MODE_NA;
229 
230 	switch (priv->phy_interface) {
231 	case PHY_INTERFACE_MODE_NA:
232 	case PHY_INTERFACE_MODE_MOCA:
233 		/* Irrespective of the actually configured PHY speed (100 or
234 		 * 1000) GENETv4 only has an internal GPHY so we will just end
235 		 * up masking the Gigabit features from what we support, not
236 		 * switching to the EPHY
237 		 */
238 		if (GENET_IS_V4(priv))
239 			port_ctrl = PORT_MODE_INT_GPHY;
240 		else
241 			port_ctrl = PORT_MODE_INT_EPHY;
242 
243 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
244 
245 		if (phy_is_internal(priv->phydev)) {
246 			phy_name = "internal PHY";
247 			bcmgenet_internal_phy_setup(dev);
248 		} else if (priv->phy_interface == PHY_INTERFACE_MODE_MOCA) {
249 			phy_name = "MoCA";
250 			bcmgenet_moca_phy_setup(priv);
251 		}
252 		break;
253 
254 	case PHY_INTERFACE_MODE_MII:
255 		phy_name = "external MII";
256 		phydev->supported &= PHY_BASIC_FEATURES;
257 		bcmgenet_sys_writel(priv,
258 				    PORT_MODE_EXT_EPHY, SYS_PORT_CTRL);
259 		break;
260 
261 	case PHY_INTERFACE_MODE_REVMII:
262 		phy_name = "external RvMII";
263 		/* of_mdiobus_register took care of reading the 'max-speed'
264 		 * PHY property for us, effectively limiting the PHY supported
265 		 * capabilities, use that knowledge to also configure the
266 		 * Reverse MII interface correctly.
267 		 */
268 		if ((priv->phydev->supported & PHY_BASIC_FEATURES) ==
269 				PHY_BASIC_FEATURES)
270 			port_ctrl = PORT_MODE_EXT_RVMII_25;
271 		else
272 			port_ctrl = PORT_MODE_EXT_RVMII_50;
273 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
274 		break;
275 
276 	case PHY_INTERFACE_MODE_RGMII:
277 		/* RGMII_NO_ID: TXC transitions at the same time as TXD
278 		 *		(requires PCB or receiver-side delay)
279 		 * RGMII:	Add 2ns delay on TXC (90 degree shift)
280 		 *
281 		 * ID is implicitly disabled for 100Mbps (RG)MII operation.
282 		 */
283 		id_mode_dis = BIT(16);
284 		/* fall through */
285 	case PHY_INTERFACE_MODE_RGMII_TXID:
286 		if (id_mode_dis)
287 			phy_name = "external RGMII (no delay)";
288 		else
289 			phy_name = "external RGMII (TX delay)";
290 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
291 		reg |= RGMII_MODE_EN | id_mode_dis;
292 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
293 		bcmgenet_sys_writel(priv,
294 				    PORT_MODE_EXT_GPHY, SYS_PORT_CTRL);
295 		break;
296 	default:
297 		dev_err(kdev, "unknown phy mode: %d\n", priv->phy_interface);
298 		return -EINVAL;
299 	}
300 
301 	if (init)
302 		dev_info(kdev, "configuring instance for %s\n", phy_name);
303 
304 	return 0;
305 }
306 
307 static int bcmgenet_mii_probe(struct net_device *dev)
308 {
309 	struct bcmgenet_priv *priv = netdev_priv(dev);
310 	struct device_node *dn = priv->pdev->dev.of_node;
311 	struct phy_device *phydev;
312 	u32 phy_flags;
313 	int ret;
314 
315 	if (priv->phydev) {
316 		pr_info("PHY already attached\n");
317 		return 0;
318 	}
319 
320 	/* In the case of a fixed PHY, the DT node associated
321 	 * to the PHY is the Ethernet MAC DT node.
322 	 */
323 	if (!priv->phy_dn && of_phy_is_fixed_link(dn)) {
324 		ret = of_phy_register_fixed_link(dn);
325 		if (ret)
326 			return ret;
327 
328 		priv->phy_dn = of_node_get(dn);
329 	}
330 
331 	/* Communicate the integrated PHY revision */
332 	phy_flags = priv->gphy_rev;
333 
334 	/* Initialize link state variables that bcmgenet_mii_setup() uses */
335 	priv->old_link = -1;
336 	priv->old_speed = -1;
337 	priv->old_duplex = -1;
338 	priv->old_pause = -1;
339 
340 	phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup,
341 				phy_flags, priv->phy_interface);
342 	if (!phydev) {
343 		pr_err("could not attach to PHY\n");
344 		return -ENODEV;
345 	}
346 
347 	priv->phydev = phydev;
348 
349 	/* Configure port multiplexer based on what the probed PHY device since
350 	 * reading the 'max-speed' property determines the maximum supported
351 	 * PHY speed which is needed for bcmgenet_mii_config() to configure
352 	 * things appropriately.
353 	 */
354 	ret = bcmgenet_mii_config(dev, true);
355 	if (ret) {
356 		phy_disconnect(priv->phydev);
357 		return ret;
358 	}
359 
360 	phydev->advertising = phydev->supported;
361 
362 	/* The internal PHY has its link interrupts routed to the
363 	 * Ethernet MAC ISRs
364 	 */
365 	if (phy_is_internal(priv->phydev))
366 		priv->mii_bus->irq[phydev->addr] = PHY_IGNORE_INTERRUPT;
367 	else
368 		priv->mii_bus->irq[phydev->addr] = PHY_POLL;
369 
370 	pr_info("attached PHY at address %d [%s]\n",
371 		phydev->addr, phydev->drv->name);
372 
373 	return 0;
374 }
375 
376 static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv)
377 {
378 	struct mii_bus *bus;
379 
380 	if (priv->mii_bus)
381 		return 0;
382 
383 	priv->mii_bus = mdiobus_alloc();
384 	if (!priv->mii_bus) {
385 		pr_err("failed to allocate\n");
386 		return -ENOMEM;
387 	}
388 
389 	bus = priv->mii_bus;
390 	bus->priv = priv->dev;
391 	bus->name = "bcmgenet MII bus";
392 	bus->parent = &priv->pdev->dev;
393 	bus->read = bcmgenet_mii_read;
394 	bus->write = bcmgenet_mii_write;
395 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d",
396 		 priv->pdev->name, priv->pdev->id);
397 
398 	bus->irq = kcalloc(PHY_MAX_ADDR, sizeof(int), GFP_KERNEL);
399 	if (!bus->irq) {
400 		mdiobus_free(priv->mii_bus);
401 		return -ENOMEM;
402 	}
403 
404 	return 0;
405 }
406 
407 static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv)
408 {
409 	struct device_node *dn = priv->pdev->dev.of_node;
410 	struct device *kdev = &priv->pdev->dev;
411 	struct device_node *mdio_dn;
412 	char *compat;
413 	int ret;
414 
415 	compat = kasprintf(GFP_KERNEL, "brcm,genet-mdio-v%d", priv->version);
416 	if (!compat)
417 		return -ENOMEM;
418 
419 	mdio_dn = of_find_compatible_node(dn, NULL, compat);
420 	kfree(compat);
421 	if (!mdio_dn) {
422 		dev_err(kdev, "unable to find MDIO bus node\n");
423 		return -ENODEV;
424 	}
425 
426 	ret = of_mdiobus_register(priv->mii_bus, mdio_dn);
427 	if (ret) {
428 		dev_err(kdev, "failed to register MDIO bus\n");
429 		return ret;
430 	}
431 
432 	/* Fetch the PHY phandle */
433 	priv->phy_dn = of_parse_phandle(dn, "phy-handle", 0);
434 
435 	/* Get the link mode */
436 	priv->phy_interface = of_get_phy_mode(dn);
437 
438 	return 0;
439 }
440 
441 int bcmgenet_mii_init(struct net_device *dev)
442 {
443 	struct bcmgenet_priv *priv = netdev_priv(dev);
444 	int ret;
445 
446 	ret = bcmgenet_mii_alloc(priv);
447 	if (ret)
448 		return ret;
449 
450 	ret = bcmgenet_mii_of_init(priv);
451 	if (ret)
452 		goto out_free;
453 
454 	ret = bcmgenet_mii_probe(dev);
455 	if (ret)
456 		goto out;
457 
458 	return 0;
459 
460 out:
461 	of_node_put(priv->phy_dn);
462 	mdiobus_unregister(priv->mii_bus);
463 out_free:
464 	kfree(priv->mii_bus->irq);
465 	mdiobus_free(priv->mii_bus);
466 	return ret;
467 }
468 
469 void bcmgenet_mii_exit(struct net_device *dev)
470 {
471 	struct bcmgenet_priv *priv = netdev_priv(dev);
472 
473 	of_node_put(priv->phy_dn);
474 	mdiobus_unregister(priv->mii_bus);
475 	kfree(priv->mii_bus->irq);
476 	mdiobus_free(priv->mii_bus);
477 }
478