1 // SPDX-License-Identifier: GPL-2.0
2 /* Microchip LAN937X switch driver main logic
3  * Copyright (C) 2019-2022 Microchip Technology Inc.
4  */
5 #include <linux/kernel.h>
6 #include <linux/module.h>
7 #include <linux/iopoll.h>
8 #include <linux/phy.h>
9 #include <linux/of_net.h>
10 #include <linux/of_mdio.h>
11 #include <linux/if_bridge.h>
12 #include <linux/if_vlan.h>
13 #include <linux/math.h>
14 #include <net/dsa.h>
15 #include <net/switchdev.h>
16 
17 #include "lan937x_reg.h"
18 #include "ksz_common.h"
19 #include "lan937x.h"
20 
21 static int lan937x_cfg(struct ksz_device *dev, u32 addr, u8 bits, bool set)
22 {
23 	return regmap_update_bits(dev->regmap[0], addr, bits, set ? bits : 0);
24 }
25 
26 static int lan937x_port_cfg(struct ksz_device *dev, int port, int offset,
27 			    u8 bits, bool set)
28 {
29 	return regmap_update_bits(dev->regmap[0], PORT_CTRL_ADDR(port, offset),
30 				  bits, set ? bits : 0);
31 }
32 
33 static int lan937x_enable_spi_indirect_access(struct ksz_device *dev)
34 {
35 	u16 data16;
36 	int ret;
37 
38 	/* Enable Phy access through SPI */
39 	ret = lan937x_cfg(dev, REG_GLOBAL_CTRL_0, SW_PHY_REG_BLOCK, false);
40 	if (ret < 0)
41 		return ret;
42 
43 	ret = ksz_read16(dev, REG_VPHY_SPECIAL_CTRL__2, &data16);
44 	if (ret < 0)
45 		return ret;
46 
47 	/* Allow SPI access */
48 	data16 |= VPHY_SPI_INDIRECT_ENABLE;
49 
50 	return ksz_write16(dev, REG_VPHY_SPECIAL_CTRL__2, data16);
51 }
52 
53 static int lan937x_vphy_ind_addr_wr(struct ksz_device *dev, int addr, int reg)
54 {
55 	u16 addr_base = REG_PORT_T1_PHY_CTRL_BASE;
56 	u16 temp;
57 
58 	/* get register address based on the logical port */
59 	temp = PORT_CTRL_ADDR(addr, (addr_base + (reg << 2)));
60 
61 	return ksz_write16(dev, REG_VPHY_IND_ADDR__2, temp);
62 }
63 
64 static int lan937x_internal_phy_write(struct ksz_device *dev, int addr, int reg,
65 				      u16 val)
66 {
67 	unsigned int value;
68 	int ret;
69 
70 	/* Check for internal phy port */
71 	if (!dev->info->internal_phy[addr])
72 		return -EOPNOTSUPP;
73 
74 	ret = lan937x_vphy_ind_addr_wr(dev, addr, reg);
75 	if (ret < 0)
76 		return ret;
77 
78 	/* Write the data to be written to the VPHY reg */
79 	ret = ksz_write16(dev, REG_VPHY_IND_DATA__2, val);
80 	if (ret < 0)
81 		return ret;
82 
83 	/* Write the Write En and Busy bit */
84 	ret = ksz_write16(dev, REG_VPHY_IND_CTRL__2,
85 			  (VPHY_IND_WRITE | VPHY_IND_BUSY));
86 	if (ret < 0)
87 		return ret;
88 
89 	ret = regmap_read_poll_timeout(dev->regmap[1], REG_VPHY_IND_CTRL__2,
90 				       value, !(value & VPHY_IND_BUSY), 10,
91 				       1000);
92 	if (ret < 0) {
93 		dev_err(dev->dev, "Failed to write phy register\n");
94 		return ret;
95 	}
96 
97 	return 0;
98 }
99 
100 static int lan937x_internal_phy_read(struct ksz_device *dev, int addr, int reg,
101 				     u16 *val)
102 {
103 	unsigned int value;
104 	int ret;
105 
106 	/* Check for internal phy port, return 0xffff for non-existent phy */
107 	if (!dev->info->internal_phy[addr])
108 		return 0xffff;
109 
110 	ret = lan937x_vphy_ind_addr_wr(dev, addr, reg);
111 	if (ret < 0)
112 		return ret;
113 
114 	/* Write Read and Busy bit to start the transaction */
115 	ret = ksz_write16(dev, REG_VPHY_IND_CTRL__2, VPHY_IND_BUSY);
116 	if (ret < 0)
117 		return ret;
118 
119 	ret = regmap_read_poll_timeout(dev->regmap[1], REG_VPHY_IND_CTRL__2,
120 				       value, !(value & VPHY_IND_BUSY), 10,
121 				       1000);
122 	if (ret < 0) {
123 		dev_err(dev->dev, "Failed to read phy register\n");
124 		return ret;
125 	}
126 
127 	/* Read the VPHY register which has the PHY data */
128 	return ksz_read16(dev, REG_VPHY_IND_DATA__2, val);
129 }
130 
131 void lan937x_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data)
132 {
133 	lan937x_internal_phy_read(dev, addr, reg, data);
134 }
135 
136 void lan937x_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val)
137 {
138 	lan937x_internal_phy_write(dev, addr, reg, val);
139 }
140 
141 static int lan937x_sw_mdio_read(struct mii_bus *bus, int addr, int regnum)
142 {
143 	struct ksz_device *dev = bus->priv;
144 	u16 val;
145 	int ret;
146 
147 	if (regnum & MII_ADDR_C45)
148 		return -EOPNOTSUPP;
149 
150 	ret = lan937x_internal_phy_read(dev, addr, regnum, &val);
151 	if (ret < 0)
152 		return ret;
153 
154 	return val;
155 }
156 
157 static int lan937x_sw_mdio_write(struct mii_bus *bus, int addr, int regnum,
158 				 u16 val)
159 {
160 	struct ksz_device *dev = bus->priv;
161 
162 	if (regnum & MII_ADDR_C45)
163 		return -EOPNOTSUPP;
164 
165 	return lan937x_internal_phy_write(dev, addr, regnum, val);
166 }
167 
168 static int lan937x_mdio_register(struct ksz_device *dev)
169 {
170 	struct dsa_switch *ds = dev->ds;
171 	struct device_node *mdio_np;
172 	struct mii_bus *bus;
173 	int ret;
174 
175 	mdio_np = of_get_child_by_name(dev->dev->of_node, "mdio");
176 	if (!mdio_np) {
177 		dev_err(ds->dev, "no MDIO bus node\n");
178 		return -ENODEV;
179 	}
180 
181 	bus = devm_mdiobus_alloc(ds->dev);
182 	if (!bus) {
183 		of_node_put(mdio_np);
184 		return -ENOMEM;
185 	}
186 
187 	bus->priv = dev;
188 	bus->read = lan937x_sw_mdio_read;
189 	bus->write = lan937x_sw_mdio_write;
190 	bus->name = "lan937x slave smi";
191 	snprintf(bus->id, MII_BUS_ID_SIZE, "SMI-%d", ds->index);
192 	bus->parent = ds->dev;
193 	bus->phy_mask = ~ds->phys_mii_mask;
194 
195 	ds->slave_mii_bus = bus;
196 
197 	ret = devm_of_mdiobus_register(ds->dev, bus, mdio_np);
198 	if (ret) {
199 		dev_err(ds->dev, "unable to register MDIO bus %s\n",
200 			bus->id);
201 	}
202 
203 	of_node_put(mdio_np);
204 
205 	return ret;
206 }
207 
208 int lan937x_reset_switch(struct ksz_device *dev)
209 {
210 	u32 data32;
211 	int ret;
212 
213 	/* reset switch */
214 	ret = lan937x_cfg(dev, REG_SW_OPERATION, SW_RESET, true);
215 	if (ret < 0)
216 		return ret;
217 
218 	/* Enable Auto Aging */
219 	ret = lan937x_cfg(dev, REG_SW_LUE_CTRL_1, SW_LINK_AUTO_AGING, true);
220 	if (ret < 0)
221 		return ret;
222 
223 	/* disable interrupts */
224 	ret = ksz_write32(dev, REG_SW_INT_MASK__4, SWITCH_INT_MASK);
225 	if (ret < 0)
226 		return ret;
227 
228 	ret = ksz_write32(dev, REG_SW_PORT_INT_MASK__4, 0xFF);
229 	if (ret < 0)
230 		return ret;
231 
232 	return ksz_read32(dev, REG_SW_PORT_INT_STATUS__4, &data32);
233 }
234 
235 void lan937x_port_setup(struct ksz_device *dev, int port, bool cpu_port)
236 {
237 	const u32 *masks = dev->info->masks;
238 	const u16 *regs = dev->info->regs;
239 	struct dsa_switch *ds = dev->ds;
240 	u8 member;
241 
242 	/* enable tag tail for host port */
243 	if (cpu_port)
244 		lan937x_port_cfg(dev, port, REG_PORT_CTRL_0,
245 				 PORT_TAIL_TAG_ENABLE, true);
246 
247 	/* disable frame check length field */
248 	lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_0, PORT_CHECK_LENGTH,
249 			 false);
250 
251 	/* set back pressure for half duplex */
252 	lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_1, PORT_BACK_PRESSURE,
253 			 true);
254 
255 	/* enable 802.1p priority */
256 	lan937x_port_cfg(dev, port, P_PRIO_CTRL, PORT_802_1P_PRIO_ENABLE, true);
257 
258 	if (!dev->info->internal_phy[port])
259 		lan937x_port_cfg(dev, port, regs[P_XMII_CTRL_0],
260 				 masks[P_MII_TX_FLOW_CTRL] |
261 				 masks[P_MII_RX_FLOW_CTRL],
262 				 true);
263 
264 	if (cpu_port)
265 		member = dsa_user_ports(ds);
266 	else
267 		member = BIT(dsa_upstream_port(ds, port));
268 
269 	dev->dev_ops->cfg_port_member(dev, port, member);
270 }
271 
272 void lan937x_config_cpu_port(struct dsa_switch *ds)
273 {
274 	struct ksz_device *dev = ds->priv;
275 	struct dsa_port *dp;
276 
277 	dsa_switch_for_each_cpu_port(dp, ds) {
278 		if (dev->info->cpu_ports & (1 << dp->index)) {
279 			dev->cpu_port = dp->index;
280 
281 			/* enable cpu port */
282 			lan937x_port_setup(dev, dp->index, true);
283 		}
284 	}
285 
286 	dsa_switch_for_each_user_port(dp, ds) {
287 		ksz_port_stp_state_set(ds, dp->index, BR_STATE_DISABLED);
288 	}
289 }
290 
291 int lan937x_change_mtu(struct ksz_device *dev, int port, int new_mtu)
292 {
293 	struct dsa_switch *ds = dev->ds;
294 	int ret;
295 
296 	new_mtu += VLAN_ETH_HLEN + ETH_FCS_LEN;
297 
298 	if (dsa_is_cpu_port(ds, port))
299 		new_mtu += LAN937X_TAG_LEN;
300 
301 	if (new_mtu >= FR_MIN_SIZE)
302 		ret = lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_0,
303 				       PORT_JUMBO_PACKET, true);
304 	else
305 		ret = lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_0,
306 				       PORT_JUMBO_PACKET, false);
307 	if (ret < 0) {
308 		dev_err(ds->dev, "failed to enable jumbo\n");
309 		return ret;
310 	}
311 
312 	/* Write the frame size in PORT_MAX_FR_SIZE register */
313 	ksz_pwrite16(dev, port, PORT_MAX_FR_SIZE, new_mtu);
314 
315 	return 0;
316 }
317 
318 static void lan937x_set_tune_adj(struct ksz_device *dev, int port,
319 				 u16 reg, u8 val)
320 {
321 	u16 data16;
322 
323 	ksz_pread16(dev, port, reg, &data16);
324 
325 	/* Update tune Adjust */
326 	data16 |= FIELD_PREP(PORT_TUNE_ADJ, val);
327 	ksz_pwrite16(dev, port, reg, data16);
328 
329 	/* write DLL reset to take effect */
330 	data16 |= PORT_DLL_RESET;
331 	ksz_pwrite16(dev, port, reg, data16);
332 }
333 
334 static void lan937x_set_rgmii_tx_delay(struct ksz_device *dev, int port)
335 {
336 	u8 val;
337 
338 	/* Apply different codes based on the ports as per characterization
339 	 * results
340 	 */
341 	val = (port == LAN937X_RGMII_1_PORT) ? RGMII_1_TX_DELAY_2NS :
342 		RGMII_2_TX_DELAY_2NS;
343 
344 	lan937x_set_tune_adj(dev, port, REG_PORT_XMII_CTRL_5, val);
345 }
346 
347 static void lan937x_set_rgmii_rx_delay(struct ksz_device *dev, int port)
348 {
349 	u8 val;
350 
351 	val = (port == LAN937X_RGMII_1_PORT) ? RGMII_1_RX_DELAY_2NS :
352 		RGMII_2_RX_DELAY_2NS;
353 
354 	lan937x_set_tune_adj(dev, port, REG_PORT_XMII_CTRL_4, val);
355 }
356 
357 void lan937x_phylink_get_caps(struct ksz_device *dev, int port,
358 			      struct phylink_config *config)
359 {
360 	config->mac_capabilities = MAC_100FD;
361 
362 	if (dev->info->supports_rgmii[port]) {
363 		/* MII/RMII/RGMII ports */
364 		config->mac_capabilities |= MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
365 					    MAC_100HD | MAC_10 | MAC_1000FD;
366 	}
367 }
368 
369 void lan937x_setup_rgmii_delay(struct ksz_device *dev, int port)
370 {
371 	struct ksz_port *p = &dev->ports[port];
372 
373 	if (p->rgmii_tx_val) {
374 		lan937x_set_rgmii_tx_delay(dev, port);
375 		dev_info(dev->dev, "Applied rgmii tx delay for the port %d\n",
376 			 port);
377 	}
378 
379 	if (p->rgmii_rx_val) {
380 		lan937x_set_rgmii_rx_delay(dev, port);
381 		dev_info(dev->dev, "Applied rgmii rx delay for the port %d\n",
382 			 port);
383 	}
384 }
385 
386 int lan937x_setup(struct dsa_switch *ds)
387 {
388 	struct ksz_device *dev = ds->priv;
389 	int ret;
390 
391 	/* enable Indirect Access from SPI to the VPHY registers */
392 	ret = lan937x_enable_spi_indirect_access(dev);
393 	if (ret < 0) {
394 		dev_err(dev->dev, "failed to enable spi indirect access");
395 		return ret;
396 	}
397 
398 	ret = lan937x_mdio_register(dev);
399 	if (ret < 0) {
400 		dev_err(dev->dev, "failed to register the mdio");
401 		return ret;
402 	}
403 
404 	/* The VLAN aware is a global setting. Mixed vlan
405 	 * filterings are not supported.
406 	 */
407 	ds->vlan_filtering_is_global = true;
408 
409 	/* Enable aggressive back off for half duplex & UNH mode */
410 	lan937x_cfg(dev, REG_SW_MAC_CTRL_0,
411 		    (SW_PAUSE_UNH_MODE | SW_NEW_BACKOFF | SW_AGGR_BACKOFF),
412 		    true);
413 
414 	/* If NO_EXC_COLLISION_DROP bit is set, the switch will not drop
415 	 * packets when 16 or more collisions occur
416 	 */
417 	lan937x_cfg(dev, REG_SW_MAC_CTRL_1, NO_EXC_COLLISION_DROP, true);
418 
419 	/* enable global MIB counter freeze function */
420 	lan937x_cfg(dev, REG_SW_MAC_CTRL_6, SW_MIB_COUNTER_FREEZE, true);
421 
422 	/* disable CLK125 & CLK25, 1: disable, 0: enable */
423 	lan937x_cfg(dev, REG_SW_GLOBAL_OUTPUT_CTRL__1,
424 		    (SW_CLK125_ENB | SW_CLK25_ENB), true);
425 
426 	return 0;
427 }
428 
429 int lan937x_switch_init(struct ksz_device *dev)
430 {
431 	dev->port_mask = (1 << dev->info->port_cnt) - 1;
432 
433 	return 0;
434 }
435 
436 void lan937x_switch_exit(struct ksz_device *dev)
437 {
438 	lan937x_reset_switch(dev);
439 }
440 
441 MODULE_AUTHOR("Arun Ramadoss <arun.ramadoss@microchip.com>");
442 MODULE_DESCRIPTION("Microchip LAN937x Series Switch DSA Driver");
443 MODULE_LICENSE("GPL");
444