1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Amlogic Meson8b, Meson8m2 and GXBB DWMAC glue layer
4  *
5  * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/device.h>
12 #include <linux/ethtool.h>
13 #include <linux/io.h>
14 #include <linux/ioport.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/of_net.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/platform_device.h>
20 #include <linux/stmmac.h>
21 
22 #include "stmmac_platform.h"
23 
24 #define PRG_ETH0			0x0
25 
26 #define PRG_ETH0_RGMII_MODE		BIT(0)
27 
28 #define PRG_ETH0_EXT_PHY_MODE_MASK	GENMASK(2, 0)
29 #define PRG_ETH0_EXT_RGMII_MODE		1
30 #define PRG_ETH0_EXT_RMII_MODE		4
31 
32 /* mux to choose between fclk_div2 (bit unset) and mpll2 (bit set) */
33 #define PRG_ETH0_CLK_M250_SEL_MASK	GENMASK(4, 4)
34 
35 /* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where 8ns are exactly one
36  * cycle of the 125MHz RGMII TX clock):
37  * 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3
38  */
39 #define PRG_ETH0_TXDLY_MASK		GENMASK(6, 5)
40 
41 /* divider for the result of m250_sel */
42 #define PRG_ETH0_CLK_M250_DIV_SHIFT	7
43 #define PRG_ETH0_CLK_M250_DIV_WIDTH	3
44 
45 #define PRG_ETH0_RGMII_TX_CLK_EN	10
46 
47 #define PRG_ETH0_INVERTED_RMII_CLK	BIT(11)
48 #define PRG_ETH0_TX_AND_PHY_REF_CLK	BIT(12)
49 
50 /* Bypass (= 0, the signal from the GPIO input directly connects to the
51  * internal sampling) or enable (= 1) the internal logic for RXEN and RXD[3:0]
52  * timing tuning.
53  */
54 #define PRG_ETH0_ADJ_ENABLE		BIT(13)
55 /* Controls whether the RXEN and RXD[3:0] signals should be aligned with the
56  * input RX rising/falling edge and sent to the Ethernet internals. This sets
57  * the automatically delay and skew automatically (internally).
58  */
59 #define PRG_ETH0_ADJ_SETUP		BIT(14)
60 /* An internal counter based on the "timing-adjustment" clock. The counter is
61  * cleared on both, the falling and rising edge of the RX_CLK. This selects the
62  * delay (= the counter value) when to start sampling RXEN and RXD[3:0].
63  */
64 #define PRG_ETH0_ADJ_DELAY		GENMASK(19, 15)
65 /* Adjusts the skew between each bit of RXEN and RXD[3:0]. If a signal has a
66  * large input delay, the bit for that signal (RXEN = bit 0, RXD[3] = bit 1,
67  * ...) can be configured to be 1 to compensate for a delay of about 1ns.
68  */
69 #define PRG_ETH0_ADJ_SKEW		GENMASK(24, 20)
70 
71 #define PRG_ETH1			0x4
72 
73 /* Defined for adding a delay to the input RX_CLK for better timing.
74  * Each step is 200ps. These bits are used with external RGMII PHYs
75  * because RGMII RX only has the small window. cfg_rxclk_dly can
76  * adjust the window between RX_CLK and RX_DATA and improve the stability
77  * of "rx data valid".
78  */
79 #define PRG_ETH1_CFG_RXCLK_DLY		GENMASK(19, 16)
80 
81 struct meson8b_dwmac;
82 
83 struct meson8b_dwmac_data {
84 	int (*set_phy_mode)(struct meson8b_dwmac *dwmac);
85 	bool has_prg_eth1_rgmii_rx_delay;
86 };
87 
88 struct meson8b_dwmac {
89 	struct device			*dev;
90 	void __iomem			*regs;
91 
92 	const struct meson8b_dwmac_data	*data;
93 	phy_interface_t			phy_mode;
94 	struct clk			*rgmii_tx_clk;
95 	u32				tx_delay_ns;
96 	u32				rx_delay_ps;
97 	struct clk			*timing_adj_clk;
98 };
99 
100 struct meson8b_dwmac_clk_configs {
101 	struct clk_mux		m250_mux;
102 	struct clk_divider	m250_div;
103 	struct clk_fixed_factor	fixed_div2;
104 	struct clk_gate		rgmii_tx_en;
105 };
106 
107 static void meson8b_dwmac_mask_bits(struct meson8b_dwmac *dwmac, u32 reg,
108 				    u32 mask, u32 value)
109 {
110 	u32 data;
111 
112 	data = readl(dwmac->regs + reg);
113 	data &= ~mask;
114 	data |= (value & mask);
115 
116 	writel(data, dwmac->regs + reg);
117 }
118 
119 static struct clk *meson8b_dwmac_register_clk(struct meson8b_dwmac *dwmac,
120 					      const char *name_suffix,
121 					      const struct clk_parent_data *parents,
122 					      int num_parents,
123 					      const struct clk_ops *ops,
124 					      struct clk_hw *hw)
125 {
126 	struct clk_init_data init = { };
127 	char clk_name[32];
128 
129 	snprintf(clk_name, sizeof(clk_name), "%s#%s", dev_name(dwmac->dev),
130 		 name_suffix);
131 
132 	init.name = clk_name;
133 	init.ops = ops;
134 	init.flags = CLK_SET_RATE_PARENT;
135 	init.parent_data = parents;
136 	init.num_parents = num_parents;
137 
138 	hw->init = &init;
139 
140 	return devm_clk_register(dwmac->dev, hw);
141 }
142 
143 static int meson8b_init_rgmii_tx_clk(struct meson8b_dwmac *dwmac)
144 {
145 	struct clk *clk;
146 	struct device *dev = dwmac->dev;
147 	static const struct clk_parent_data mux_parents[] = {
148 		{ .fw_name = "clkin0", },
149 		{ .index = -1, },
150 	};
151 	static const struct clk_div_table div_table[] = {
152 		{ .div = 2, .val = 2, },
153 		{ .div = 3, .val = 3, },
154 		{ .div = 4, .val = 4, },
155 		{ .div = 5, .val = 5, },
156 		{ .div = 6, .val = 6, },
157 		{ .div = 7, .val = 7, },
158 		{ /* end of array */ }
159 	};
160 	struct meson8b_dwmac_clk_configs *clk_configs;
161 	struct clk_parent_data parent_data = { };
162 
163 	clk_configs = devm_kzalloc(dev, sizeof(*clk_configs), GFP_KERNEL);
164 	if (!clk_configs)
165 		return -ENOMEM;
166 
167 	clk_configs->m250_mux.reg = dwmac->regs + PRG_ETH0;
168 	clk_configs->m250_mux.shift = __ffs(PRG_ETH0_CLK_M250_SEL_MASK);
169 	clk_configs->m250_mux.mask = PRG_ETH0_CLK_M250_SEL_MASK >>
170 				     clk_configs->m250_mux.shift;
171 	clk = meson8b_dwmac_register_clk(dwmac, "m250_sel", mux_parents,
172 					 ARRAY_SIZE(mux_parents), &clk_mux_ops,
173 					 &clk_configs->m250_mux.hw);
174 	if (WARN_ON(IS_ERR(clk)))
175 		return PTR_ERR(clk);
176 
177 	parent_data.hw = &clk_configs->m250_mux.hw;
178 	clk_configs->m250_div.reg = dwmac->regs + PRG_ETH0;
179 	clk_configs->m250_div.shift = PRG_ETH0_CLK_M250_DIV_SHIFT;
180 	clk_configs->m250_div.width = PRG_ETH0_CLK_M250_DIV_WIDTH;
181 	clk_configs->m250_div.table = div_table;
182 	clk_configs->m250_div.flags = CLK_DIVIDER_ALLOW_ZERO |
183 				      CLK_DIVIDER_ROUND_CLOSEST;
184 	clk = meson8b_dwmac_register_clk(dwmac, "m250_div", &parent_data, 1,
185 					 &clk_divider_ops,
186 					 &clk_configs->m250_div.hw);
187 	if (WARN_ON(IS_ERR(clk)))
188 		return PTR_ERR(clk);
189 
190 	parent_data.hw = &clk_configs->m250_div.hw;
191 	clk_configs->fixed_div2.mult = 1;
192 	clk_configs->fixed_div2.div = 2;
193 	clk = meson8b_dwmac_register_clk(dwmac, "fixed_div2", &parent_data, 1,
194 					 &clk_fixed_factor_ops,
195 					 &clk_configs->fixed_div2.hw);
196 	if (WARN_ON(IS_ERR(clk)))
197 		return PTR_ERR(clk);
198 
199 	parent_data.hw = &clk_configs->fixed_div2.hw;
200 	clk_configs->rgmii_tx_en.reg = dwmac->regs + PRG_ETH0;
201 	clk_configs->rgmii_tx_en.bit_idx = PRG_ETH0_RGMII_TX_CLK_EN;
202 	clk = meson8b_dwmac_register_clk(dwmac, "rgmii_tx_en", &parent_data, 1,
203 					 &clk_gate_ops,
204 					 &clk_configs->rgmii_tx_en.hw);
205 	if (WARN_ON(IS_ERR(clk)))
206 		return PTR_ERR(clk);
207 
208 	dwmac->rgmii_tx_clk = clk;
209 
210 	return 0;
211 }
212 
213 static int meson8b_set_phy_mode(struct meson8b_dwmac *dwmac)
214 {
215 	switch (dwmac->phy_mode) {
216 	case PHY_INTERFACE_MODE_RGMII:
217 	case PHY_INTERFACE_MODE_RGMII_RXID:
218 	case PHY_INTERFACE_MODE_RGMII_ID:
219 	case PHY_INTERFACE_MODE_RGMII_TXID:
220 		/* enable RGMII mode */
221 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
222 					PRG_ETH0_RGMII_MODE,
223 					PRG_ETH0_RGMII_MODE);
224 		break;
225 	case PHY_INTERFACE_MODE_RMII:
226 		/* disable RGMII mode -> enables RMII mode */
227 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
228 					PRG_ETH0_RGMII_MODE, 0);
229 		break;
230 	default:
231 		dev_err(dwmac->dev, "fail to set phy-mode %s\n",
232 			phy_modes(dwmac->phy_mode));
233 		return -EINVAL;
234 	}
235 
236 	return 0;
237 }
238 
239 static int meson_axg_set_phy_mode(struct meson8b_dwmac *dwmac)
240 {
241 	switch (dwmac->phy_mode) {
242 	case PHY_INTERFACE_MODE_RGMII:
243 	case PHY_INTERFACE_MODE_RGMII_RXID:
244 	case PHY_INTERFACE_MODE_RGMII_ID:
245 	case PHY_INTERFACE_MODE_RGMII_TXID:
246 		/* enable RGMII mode */
247 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
248 					PRG_ETH0_EXT_PHY_MODE_MASK,
249 					PRG_ETH0_EXT_RGMII_MODE);
250 		break;
251 	case PHY_INTERFACE_MODE_RMII:
252 		/* disable RGMII mode -> enables RMII mode */
253 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
254 					PRG_ETH0_EXT_PHY_MODE_MASK,
255 					PRG_ETH0_EXT_RMII_MODE);
256 		break;
257 	default:
258 		dev_err(dwmac->dev, "fail to set phy-mode %s\n",
259 			phy_modes(dwmac->phy_mode));
260 		return -EINVAL;
261 	}
262 
263 	return 0;
264 }
265 
266 static int meson8b_devm_clk_prepare_enable(struct meson8b_dwmac *dwmac,
267 					   struct clk *clk)
268 {
269 	int ret;
270 
271 	ret = clk_prepare_enable(clk);
272 	if (ret)
273 		return ret;
274 
275 	return devm_add_action_or_reset(dwmac->dev,
276 					(void(*)(void *))clk_disable_unprepare,
277 					clk);
278 }
279 
280 static int meson8b_init_rgmii_delays(struct meson8b_dwmac *dwmac)
281 {
282 	u32 tx_dly_config, rx_adj_config, cfg_rxclk_dly, delay_config;
283 	int ret;
284 
285 	rx_adj_config = 0;
286 	cfg_rxclk_dly = 0;
287 	tx_dly_config = FIELD_PREP(PRG_ETH0_TXDLY_MASK,
288 				   dwmac->tx_delay_ns >> 1);
289 
290 	if (dwmac->data->has_prg_eth1_rgmii_rx_delay)
291 		cfg_rxclk_dly = FIELD_PREP(PRG_ETH1_CFG_RXCLK_DLY,
292 					   dwmac->rx_delay_ps / 200);
293 	else if (dwmac->rx_delay_ps == 2000)
294 		rx_adj_config = PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP;
295 
296 	switch (dwmac->phy_mode) {
297 	case PHY_INTERFACE_MODE_RGMII:
298 		delay_config = tx_dly_config | rx_adj_config;
299 		break;
300 	case PHY_INTERFACE_MODE_RGMII_RXID:
301 		delay_config = tx_dly_config;
302 		cfg_rxclk_dly = 0;
303 		break;
304 	case PHY_INTERFACE_MODE_RGMII_TXID:
305 		delay_config = rx_adj_config;
306 		break;
307 	case PHY_INTERFACE_MODE_RGMII_ID:
308 	case PHY_INTERFACE_MODE_RMII:
309 		delay_config = 0;
310 		cfg_rxclk_dly = 0;
311 		break;
312 	default:
313 		dev_err(dwmac->dev, "unsupported phy-mode %s\n",
314 			phy_modes(dwmac->phy_mode));
315 		return -EINVAL;
316 	}
317 
318 	if (delay_config & PRG_ETH0_ADJ_ENABLE) {
319 		if (!dwmac->timing_adj_clk) {
320 			dev_err(dwmac->dev,
321 				"The timing-adjustment clock is mandatory for the RX delay re-timing\n");
322 			return -EINVAL;
323 		}
324 
325 		/* The timing adjustment logic is driven by a separate clock */
326 		ret = meson8b_devm_clk_prepare_enable(dwmac,
327 						      dwmac->timing_adj_clk);
328 		if (ret) {
329 			dev_err(dwmac->dev,
330 				"Failed to enable the timing-adjustment clock\n");
331 			return ret;
332 		}
333 	}
334 
335 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK |
336 				PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP |
337 				PRG_ETH0_ADJ_DELAY | PRG_ETH0_ADJ_SKEW,
338 				delay_config);
339 
340 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH1, PRG_ETH1_CFG_RXCLK_DLY,
341 				cfg_rxclk_dly);
342 
343 	return 0;
344 }
345 
346 static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
347 {
348 	int ret;
349 
350 	if (phy_interface_mode_is_rgmii(dwmac->phy_mode)) {
351 		/* only relevant for RMII mode -> disable in RGMII mode */
352 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
353 					PRG_ETH0_INVERTED_RMII_CLK, 0);
354 
355 		/* Configure the 125MHz RGMII TX clock, the IP block changes
356 		 * the output automatically (= without us having to configure
357 		 * a register) based on the line-speed (125MHz for Gbit speeds,
358 		 * 25MHz for 100Mbit/s and 2.5MHz for 10Mbit/s).
359 		 */
360 		ret = clk_set_rate(dwmac->rgmii_tx_clk, 125 * 1000 * 1000);
361 		if (ret) {
362 			dev_err(dwmac->dev,
363 				"failed to set RGMII TX clock\n");
364 			return ret;
365 		}
366 
367 		ret = meson8b_devm_clk_prepare_enable(dwmac,
368 						      dwmac->rgmii_tx_clk);
369 		if (ret) {
370 			dev_err(dwmac->dev,
371 				"failed to enable the RGMII TX clock\n");
372 			return ret;
373 		}
374 	} else {
375 		/* invert internal clk_rmii_i to generate 25/2.5 tx_rx_clk */
376 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
377 					PRG_ETH0_INVERTED_RMII_CLK,
378 					PRG_ETH0_INVERTED_RMII_CLK);
379 	}
380 
381 	/* enable TX_CLK and PHY_REF_CLK generator */
382 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TX_AND_PHY_REF_CLK,
383 				PRG_ETH0_TX_AND_PHY_REF_CLK);
384 
385 	return 0;
386 }
387 
388 static int meson8b_dwmac_probe(struct platform_device *pdev)
389 {
390 	struct plat_stmmacenet_data *plat_dat;
391 	struct stmmac_resources stmmac_res;
392 	struct meson8b_dwmac *dwmac;
393 	int ret;
394 
395 	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
396 	if (ret)
397 		return ret;
398 
399 	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
400 	if (IS_ERR(plat_dat))
401 		return PTR_ERR(plat_dat);
402 
403 	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
404 	if (!dwmac) {
405 		ret = -ENOMEM;
406 		goto err_remove_config_dt;
407 	}
408 
409 	dwmac->data = (const struct meson8b_dwmac_data *)
410 		of_device_get_match_data(&pdev->dev);
411 	if (!dwmac->data) {
412 		ret = -EINVAL;
413 		goto err_remove_config_dt;
414 	}
415 	dwmac->regs = devm_platform_ioremap_resource(pdev, 1);
416 	if (IS_ERR(dwmac->regs)) {
417 		ret = PTR_ERR(dwmac->regs);
418 		goto err_remove_config_dt;
419 	}
420 
421 	dwmac->dev = &pdev->dev;
422 	ret = of_get_phy_mode(pdev->dev.of_node, &dwmac->phy_mode);
423 	if (ret) {
424 		dev_err(&pdev->dev, "missing phy-mode property\n");
425 		goto err_remove_config_dt;
426 	}
427 
428 	/* use 2ns as fallback since this value was previously hardcoded */
429 	if (of_property_read_u32(pdev->dev.of_node, "amlogic,tx-delay-ns",
430 				 &dwmac->tx_delay_ns))
431 		dwmac->tx_delay_ns = 2;
432 
433 	/* RX delay defaults to 0ps since this is what many boards use */
434 	if (of_property_read_u32(pdev->dev.of_node, "rx-internal-delay-ps",
435 				 &dwmac->rx_delay_ps)) {
436 		if (!of_property_read_u32(pdev->dev.of_node,
437 					  "amlogic,rx-delay-ns",
438 					  &dwmac->rx_delay_ps))
439 			/* convert ns to ps */
440 			dwmac->rx_delay_ps *= 1000;
441 	}
442 
443 	if (dwmac->data->has_prg_eth1_rgmii_rx_delay) {
444 		if (dwmac->rx_delay_ps > 3000 || dwmac->rx_delay_ps % 200) {
445 			dev_err(dwmac->dev,
446 				"The RGMII RX delay range is 0..3000ps in 200ps steps");
447 			ret = -EINVAL;
448 			goto err_remove_config_dt;
449 		}
450 	} else {
451 		if (dwmac->rx_delay_ps != 0 && dwmac->rx_delay_ps != 2000) {
452 			dev_err(dwmac->dev,
453 				"The only allowed RGMII RX delays values are: 0ps, 2000ps");
454 			ret = -EINVAL;
455 			goto err_remove_config_dt;
456 		}
457 	}
458 
459 	dwmac->timing_adj_clk = devm_clk_get_optional(dwmac->dev,
460 						      "timing-adjustment");
461 	if (IS_ERR(dwmac->timing_adj_clk)) {
462 		ret = PTR_ERR(dwmac->timing_adj_clk);
463 		goto err_remove_config_dt;
464 	}
465 
466 	ret = meson8b_init_rgmii_delays(dwmac);
467 	if (ret)
468 		goto err_remove_config_dt;
469 
470 	ret = meson8b_init_rgmii_tx_clk(dwmac);
471 	if (ret)
472 		goto err_remove_config_dt;
473 
474 	ret = dwmac->data->set_phy_mode(dwmac);
475 	if (ret)
476 		goto err_remove_config_dt;
477 
478 	ret = meson8b_init_prg_eth(dwmac);
479 	if (ret)
480 		goto err_remove_config_dt;
481 
482 	plat_dat->bsp_priv = dwmac;
483 
484 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
485 	if (ret)
486 		goto err_remove_config_dt;
487 
488 	return 0;
489 
490 err_remove_config_dt:
491 	stmmac_remove_config_dt(pdev, plat_dat);
492 
493 	return ret;
494 }
495 
496 static const struct meson8b_dwmac_data meson8b_dwmac_data = {
497 	.set_phy_mode = meson8b_set_phy_mode,
498 	.has_prg_eth1_rgmii_rx_delay = false,
499 };
500 
501 static const struct meson8b_dwmac_data meson_axg_dwmac_data = {
502 	.set_phy_mode = meson_axg_set_phy_mode,
503 	.has_prg_eth1_rgmii_rx_delay = false,
504 };
505 
506 static const struct meson8b_dwmac_data meson_g12a_dwmac_data = {
507 	.set_phy_mode = meson_axg_set_phy_mode,
508 	.has_prg_eth1_rgmii_rx_delay = true,
509 };
510 
511 static const struct of_device_id meson8b_dwmac_match[] = {
512 	{
513 		.compatible = "amlogic,meson8b-dwmac",
514 		.data = &meson8b_dwmac_data,
515 	},
516 	{
517 		.compatible = "amlogic,meson8m2-dwmac",
518 		.data = &meson8b_dwmac_data,
519 	},
520 	{
521 		.compatible = "amlogic,meson-gxbb-dwmac",
522 		.data = &meson8b_dwmac_data,
523 	},
524 	{
525 		.compatible = "amlogic,meson-axg-dwmac",
526 		.data = &meson_axg_dwmac_data,
527 	},
528 	{
529 		.compatible = "amlogic,meson-g12a-dwmac",
530 		.data = &meson_g12a_dwmac_data,
531 	},
532 	{ }
533 };
534 MODULE_DEVICE_TABLE(of, meson8b_dwmac_match);
535 
536 static struct platform_driver meson8b_dwmac_driver = {
537 	.probe  = meson8b_dwmac_probe,
538 	.remove = stmmac_pltfr_remove,
539 	.driver = {
540 		.name           = "meson8b-dwmac",
541 		.pm		= &stmmac_pltfr_pm_ops,
542 		.of_match_table = meson8b_dwmac_match,
543 	},
544 };
545 module_platform_driver(meson8b_dwmac_driver);
546 
547 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
548 MODULE_DESCRIPTION("Amlogic Meson8b, Meson8m2 and GXBB DWMAC glue layer");
549 MODULE_LICENSE("GPL v2");
550