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  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19 
20 
21 #include <linux/types.h>
22 #include <linux/delay.h>
23 #include <linux/wait.h>
24 #include <linux/mii.h>
25 #include <linux/ethtool.h>
26 #include <linux/bitops.h>
27 #include <linux/netdevice.h>
28 #include <linux/platform_device.h>
29 #include <linux/phy.h>
30 #include <linux/phy_fixed.h>
31 #include <linux/brcmphy.h>
32 #include <linux/of.h>
33 #include <linux/of_net.h>
34 #include <linux/of_mdio.h>
35 
36 #include "bcmgenet.h"
37 
38 /* read a value from the MII */
39 static int bcmgenet_mii_read(struct mii_bus *bus, int phy_id, int location)
40 {
41 	int ret;
42 	struct net_device *dev = bus->priv;
43 	struct bcmgenet_priv *priv = netdev_priv(dev);
44 	u32 reg;
45 
46 	bcmgenet_umac_writel(priv, (MDIO_RD | (phy_id << MDIO_PMD_SHIFT) |
47 			(location << MDIO_REG_SHIFT)), UMAC_MDIO_CMD);
48 	/* Start MDIO transaction*/
49 	reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
50 	reg |= MDIO_START_BUSY;
51 	bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
52 	wait_event_timeout(priv->wq,
53 			!(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD)
54 				& MDIO_START_BUSY),
55 			HZ / 100);
56 	ret = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
57 
58 	if (ret & MDIO_READ_FAIL)
59 		return -EIO;
60 
61 	return ret & 0xffff;
62 }
63 
64 /* write a value to the MII */
65 static int bcmgenet_mii_write(struct mii_bus *bus, int phy_id,
66 			int location, u16 val)
67 {
68 	struct net_device *dev = bus->priv;
69 	struct bcmgenet_priv *priv = netdev_priv(dev);
70 	u32 reg;
71 
72 	bcmgenet_umac_writel(priv, (MDIO_WR | (phy_id << MDIO_PMD_SHIFT) |
73 			(location << MDIO_REG_SHIFT) | (0xffff & val)),
74 			UMAC_MDIO_CMD);
75 	reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
76 	reg |= MDIO_START_BUSY;
77 	bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
78 	wait_event_timeout(priv->wq,
79 			!(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD) &
80 				MDIO_START_BUSY),
81 			HZ / 100);
82 
83 	return 0;
84 }
85 
86 /* setup netdev link state when PHY link status change and
87  * update UMAC and RGMII block when link up
88  */
89 static void bcmgenet_mii_setup(struct net_device *dev)
90 {
91 	struct bcmgenet_priv *priv = netdev_priv(dev);
92 	struct phy_device *phydev = priv->phydev;
93 	u32 reg, cmd_bits = 0;
94 	unsigned int status_changed = 0;
95 
96 	if (priv->old_link != phydev->link) {
97 		status_changed = 1;
98 		priv->old_link = phydev->link;
99 	}
100 
101 	if (phydev->link) {
102 		/* program UMAC and RGMII block based on established link
103 		 * speed, pause, and duplex.
104 		 * the speed set in umac->cmd tell RGMII block which clock
105 		 * 25MHz(100Mbps)/125MHz(1Gbps) to use for transmit.
106 		 * receive clock is provided by PHY.
107 		 */
108 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
109 		reg &= ~OOB_DISABLE;
110 		reg |= RGMII_LINK;
111 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
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 		if (priv->old_duplex != phydev->duplex) {
123 			status_changed = 1;
124 			priv->old_duplex = phydev->duplex;
125 		}
126 
127 		/* duplex */
128 		if (phydev->duplex != DUPLEX_FULL)
129 			cmd_bits |= CMD_HD_EN;
130 
131 		if (priv->old_pause != phydev->pause) {
132 			status_changed = 1;
133 			priv->old_pause = phydev->pause;
134 		}
135 
136 		/* pause capability */
137 		if (!phydev->pause)
138 			cmd_bits |= CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE;
139 
140 		reg = bcmgenet_umac_readl(priv, UMAC_CMD);
141 		reg &= ~((CMD_SPEED_MASK << CMD_SPEED_SHIFT) |
142 			       CMD_HD_EN |
143 			       CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE);
144 		reg |= cmd_bits;
145 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
146 	}
147 
148 	if (status_changed)
149 		phy_print_status(phydev);
150 }
151 
152 void bcmgenet_mii_reset(struct net_device *dev)
153 {
154 	struct bcmgenet_priv *priv = netdev_priv(dev);
155 
156 	if (priv->phydev) {
157 		phy_init_hw(priv->phydev);
158 		phy_start_aneg(priv->phydev);
159 	}
160 }
161 
162 static void bcmgenet_ephy_power_up(struct net_device *dev)
163 {
164 	struct bcmgenet_priv *priv = netdev_priv(dev);
165 	u32 reg = 0;
166 
167 	/* EXT_GPHY_CTRL is only valid for GENETv4 and onward */
168 	if (!GENET_IS_V4(priv))
169 		return;
170 
171 	reg = bcmgenet_ext_readl(priv, EXT_GPHY_CTRL);
172 	reg &= ~(EXT_CFG_IDDQ_BIAS | EXT_CFG_PWR_DOWN);
173 	reg |= EXT_GPHY_RESET;
174 	bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
175 	mdelay(2);
176 
177 	reg &= ~EXT_GPHY_RESET;
178 	bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
179 	udelay(20);
180 }
181 
182 static void bcmgenet_internal_phy_setup(struct net_device *dev)
183 {
184 	struct bcmgenet_priv *priv = netdev_priv(dev);
185 	u32 reg;
186 
187 	/* Power up EPHY */
188 	bcmgenet_ephy_power_up(dev);
189 	/* enable APD */
190 	reg = bcmgenet_ext_readl(priv, EXT_EXT_PWR_MGMT);
191 	reg |= EXT_PWR_DN_EN_LD;
192 	bcmgenet_ext_writel(priv, reg, EXT_EXT_PWR_MGMT);
193 	bcmgenet_mii_reset(dev);
194 }
195 
196 static void bcmgenet_moca_phy_setup(struct bcmgenet_priv *priv)
197 {
198 	u32 reg;
199 
200 	/* Speed settings are set in bcmgenet_mii_setup() */
201 	reg = bcmgenet_sys_readl(priv, SYS_PORT_CTRL);
202 	reg |= LED_ACT_SOURCE_MAC;
203 	bcmgenet_sys_writel(priv, reg, SYS_PORT_CTRL);
204 }
205 
206 int bcmgenet_mii_config(struct net_device *dev)
207 {
208 	struct bcmgenet_priv *priv = netdev_priv(dev);
209 	struct phy_device *phydev = priv->phydev;
210 	struct device *kdev = &priv->pdev->dev;
211 	const char *phy_name = NULL;
212 	u32 id_mode_dis = 0;
213 	u32 port_ctrl;
214 	u32 reg;
215 
216 	priv->ext_phy = !phy_is_internal(priv->phydev) &&
217 			(priv->phy_interface != PHY_INTERFACE_MODE_MOCA);
218 
219 	if (phy_is_internal(priv->phydev))
220 		priv->phy_interface = PHY_INTERFACE_MODE_NA;
221 
222 	switch (priv->phy_interface) {
223 	case PHY_INTERFACE_MODE_NA:
224 	case PHY_INTERFACE_MODE_MOCA:
225 		/* Irrespective of the actually configured PHY speed (100 or
226 		 * 1000) GENETv4 only has an internal GPHY so we will just end
227 		 * up masking the Gigabit features from what we support, not
228 		 * switching to the EPHY
229 		 */
230 		if (GENET_IS_V4(priv))
231 			port_ctrl = PORT_MODE_INT_GPHY;
232 		else
233 			port_ctrl = PORT_MODE_INT_EPHY;
234 
235 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
236 
237 		if (phy_is_internal(priv->phydev)) {
238 			phy_name = "internal PHY";
239 			bcmgenet_internal_phy_setup(dev);
240 		} else if (priv->phy_interface == PHY_INTERFACE_MODE_MOCA) {
241 			phy_name = "MoCA";
242 			bcmgenet_moca_phy_setup(priv);
243 		}
244 		break;
245 
246 	case PHY_INTERFACE_MODE_MII:
247 		phy_name = "external MII";
248 		phydev->supported &= PHY_BASIC_FEATURES;
249 		bcmgenet_sys_writel(priv,
250 				PORT_MODE_EXT_EPHY, SYS_PORT_CTRL);
251 		break;
252 
253 	case PHY_INTERFACE_MODE_REVMII:
254 		phy_name = "external RvMII";
255 		/* of_mdiobus_register took care of reading the 'max-speed'
256 		 * PHY property for us, effectively limiting the PHY supported
257 		 * capabilities, use that knowledge to also configure the
258 		 * Reverse MII interface correctly.
259 		 */
260 		if ((priv->phydev->supported & PHY_BASIC_FEATURES) ==
261 				PHY_BASIC_FEATURES)
262 			port_ctrl = PORT_MODE_EXT_RVMII_25;
263 		else
264 			port_ctrl = PORT_MODE_EXT_RVMII_50;
265 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
266 		break;
267 
268 	case PHY_INTERFACE_MODE_RGMII:
269 		/* RGMII_NO_ID: TXC transitions at the same time as TXD
270 		 *		(requires PCB or receiver-side delay)
271 		 * RGMII:	Add 2ns delay on TXC (90 degree shift)
272 		 *
273 		 * ID is implicitly disabled for 100Mbps (RG)MII operation.
274 		 */
275 		id_mode_dis = BIT(16);
276 		/* fall through */
277 	case PHY_INTERFACE_MODE_RGMII_TXID:
278 		if (id_mode_dis)
279 			phy_name = "external RGMII (no delay)";
280 		else
281 			phy_name = "external RGMII (TX delay)";
282 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
283 		reg |= RGMII_MODE_EN | id_mode_dis;
284 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
285 		bcmgenet_sys_writel(priv,
286 				PORT_MODE_EXT_GPHY, SYS_PORT_CTRL);
287 		break;
288 	default:
289 		dev_err(kdev, "unknown phy mode: %d\n", priv->phy_interface);
290 		return -EINVAL;
291 	}
292 
293 	dev_info(kdev, "configuring instance for %s\n", phy_name);
294 
295 	return 0;
296 }
297 
298 static int bcmgenet_mii_probe(struct net_device *dev)
299 {
300 	struct bcmgenet_priv *priv = netdev_priv(dev);
301 	struct device_node *dn = priv->pdev->dev.of_node;
302 	struct phy_device *phydev;
303 	unsigned int phy_flags;
304 	int ret;
305 
306 	if (priv->phydev) {
307 		pr_info("PHY already attached\n");
308 		return 0;
309 	}
310 
311 	/* In the case of a fixed PHY, the DT node associated
312 	 * to the PHY is the Ethernet MAC DT node.
313 	 */
314 	if (of_phy_is_fixed_link(dn)) {
315 		ret = of_phy_register_fixed_link(dn);
316 		if (ret)
317 			return ret;
318 
319 		priv->phy_dn = dn;
320 	}
321 
322 	phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup, 0,
323 				priv->phy_interface);
324 	if (!phydev) {
325 		pr_err("could not attach to PHY\n");
326 		return -ENODEV;
327 	}
328 
329 	priv->old_link = -1;
330 	priv->old_duplex = -1;
331 	priv->old_pause = -1;
332 	priv->phydev = phydev;
333 
334 	/* Configure port multiplexer based on what the probed PHY device since
335 	 * reading the 'max-speed' property determines the maximum supported
336 	 * PHY speed which is needed for bcmgenet_mii_config() to configure
337 	 * things appropriately.
338 	 */
339 	ret = bcmgenet_mii_config(dev);
340 	if (ret) {
341 		phy_disconnect(priv->phydev);
342 		return ret;
343 	}
344 
345 	phy_flags = PHY_BRCM_100MBPS_WAR;
346 
347 	/* workarounds are only needed for 100Mpbs PHYs, and
348 	 * never on GENET V1 hardware
349 	 */
350 	if ((phydev->supported & PHY_GBIT_FEATURES) || GENET_IS_V1(priv))
351 		phy_flags = 0;
352 
353 	phydev->dev_flags |= phy_flags;
354 	phydev->advertising = phydev->supported;
355 
356 	/* The internal PHY has its link interrupts routed to the
357 	 * Ethernet MAC ISRs
358 	 */
359 	if (phy_is_internal(priv->phydev))
360 		priv->mii_bus->irq[phydev->addr] = PHY_IGNORE_INTERRUPT;
361 	else
362 		priv->mii_bus->irq[phydev->addr] = PHY_POLL;
363 
364 	pr_info("attached PHY at address %d [%s]\n",
365 			phydev->addr, phydev->drv->name);
366 
367 	return 0;
368 }
369 
370 static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv)
371 {
372 	struct mii_bus *bus;
373 
374 	if (priv->mii_bus)
375 		return 0;
376 
377 	priv->mii_bus = mdiobus_alloc();
378 	if (!priv->mii_bus) {
379 		pr_err("failed to allocate\n");
380 		return -ENOMEM;
381 	}
382 
383 	bus = priv->mii_bus;
384 	bus->priv = priv->dev;
385 	bus->name = "bcmgenet MII bus";
386 	bus->parent = &priv->pdev->dev;
387 	bus->read = bcmgenet_mii_read;
388 	bus->write = bcmgenet_mii_write;
389 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d",
390 			priv->pdev->name, priv->pdev->id);
391 
392 	bus->irq = kzalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
393 	if (!bus->irq) {
394 		mdiobus_free(priv->mii_bus);
395 		return -ENOMEM;
396 	}
397 
398 	return 0;
399 }
400 
401 static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv)
402 {
403 	struct device_node *dn = priv->pdev->dev.of_node;
404 	struct device *kdev = &priv->pdev->dev;
405 	struct device_node *mdio_dn;
406 	char *compat;
407 	int ret;
408 
409 	compat = kasprintf(GFP_KERNEL, "brcm,genet-mdio-v%d", priv->version);
410 	if (!compat)
411 		return -ENOMEM;
412 
413 	mdio_dn = of_find_compatible_node(dn, NULL, compat);
414 	kfree(compat);
415 	if (!mdio_dn) {
416 		dev_err(kdev, "unable to find MDIO bus node\n");
417 		return -ENODEV;
418 	}
419 
420 	ret = of_mdiobus_register(priv->mii_bus, mdio_dn);
421 	if (ret) {
422 		dev_err(kdev, "failed to register MDIO bus\n");
423 		return ret;
424 	}
425 
426 	/* Fetch the PHY phandle */
427 	priv->phy_dn = of_parse_phandle(dn, "phy-handle", 0);
428 
429 	/* Get the link mode */
430 	priv->phy_interface = of_get_phy_mode(dn);
431 
432 	return 0;
433 }
434 
435 int bcmgenet_mii_init(struct net_device *dev)
436 {
437 	struct bcmgenet_priv *priv = netdev_priv(dev);
438 	int ret;
439 
440 	ret = bcmgenet_mii_alloc(priv);
441 	if (ret)
442 		return ret;
443 
444 	ret = bcmgenet_mii_of_init(priv);
445 	if (ret)
446 		goto out_free;
447 
448 	ret = bcmgenet_mii_probe(dev);
449 	if (ret)
450 		goto out;
451 
452 	return 0;
453 
454 out:
455 	mdiobus_unregister(priv->mii_bus);
456 out_free:
457 	kfree(priv->mii_bus->irq);
458 	mdiobus_free(priv->mii_bus);
459 	return ret;
460 }
461 
462 void bcmgenet_mii_exit(struct net_device *dev)
463 {
464 	struct bcmgenet_priv *priv = netdev_priv(dev);
465 
466 	mdiobus_unregister(priv->mii_bus);
467 	kfree(priv->mii_bus->irq);
468 	mdiobus_free(priv->mii_bus);
469 }
470