xref: /linux/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c (revision 8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88)
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.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 
30 /* mux to choose between fclk_div2 (bit unset) and mpll2 (bit set) */
31 #define PRG_ETH0_CLK_M250_SEL_MASK	GENMASK(4, 4)
32 
33 /* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where 8ns are exactly one
34  * cycle of the 125MHz RGMII TX clock):
35  * 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3
36  */
37 #define PRG_ETH0_TXDLY_MASK		GENMASK(6, 5)
38 
39 /* divider for the result of m250_sel */
40 #define PRG_ETH0_CLK_M250_DIV_SHIFT	7
41 #define PRG_ETH0_CLK_M250_DIV_WIDTH	3
42 
43 #define PRG_ETH0_RGMII_TX_CLK_EN	10
44 
45 #define PRG_ETH0_INVERTED_RMII_CLK	BIT(11)
46 #define PRG_ETH0_TX_AND_PHY_REF_CLK	BIT(12)
47 
48 /* Bypass (= 0, the signal from the GPIO input directly connects to the
49  * internal sampling) or enable (= 1) the internal logic for RXEN and RXD[3:0]
50  * timing tuning.
51  */
52 #define PRG_ETH0_ADJ_ENABLE		BIT(13)
53 /* Controls whether the RXEN and RXD[3:0] signals should be aligned with the
54  * input RX rising/falling edge and sent to the Ethernet internals. This sets
55  * the automatically delay and skew automatically (internally).
56  */
57 #define PRG_ETH0_ADJ_SETUP		BIT(14)
58 /* An internal counter based on the "timing-adjustment" clock. The counter is
59  * cleared on both, the falling and rising edge of the RX_CLK. This selects the
60  * delay (= the counter value) when to start sampling RXEN and RXD[3:0].
61  */
62 #define PRG_ETH0_ADJ_DELAY		GENMASK(19, 15)
63 /* Adjusts the skew between each bit of RXEN and RXD[3:0]. If a signal has a
64  * large input delay, the bit for that signal (RXEN = bit 0, RXD[3] = bit 1,
65  * ...) can be configured to be 1 to compensate for a delay of about 1ns.
66  */
67 #define PRG_ETH0_ADJ_SKEW		GENMASK(24, 20)
68 
69 #define PRG_ETH1			0x4
70 
71 /* Defined for adding a delay to the input RX_CLK for better timing.
72  * Each step is 200ps. These bits are used with external RGMII PHYs
73  * because RGMII RX only has the small window. cfg_rxclk_dly can
74  * adjust the window between RX_CLK and RX_DATA and improve the stability
75  * of "rx data valid".
76  */
77 #define PRG_ETH1_CFG_RXCLK_DLY		GENMASK(19, 16)
78 
79 struct meson8b_dwmac;
80 
81 struct meson8b_dwmac_data {
82 	int (*set_phy_mode)(struct meson8b_dwmac *dwmac);
83 	bool has_prg_eth1_rgmii_rx_delay;
84 };
85 
86 struct meson8b_dwmac {
87 	struct device			*dev;
88 	void __iomem			*regs;
89 
90 	const struct meson8b_dwmac_data	*data;
91 	phy_interface_t			phy_mode;
92 	struct clk			*rgmii_tx_clk;
93 	u32				tx_delay_ns;
94 	u32				rx_delay_ps;
95 	struct clk			*timing_adj_clk;
96 };
97 
98 struct meson8b_dwmac_clk_configs {
99 	struct clk_mux		m250_mux;
100 	struct clk_divider	m250_div;
101 	struct clk_fixed_factor	fixed_div2;
102 	struct clk_gate		rgmii_tx_en;
103 };
104 
105 static void meson8b_dwmac_mask_bits(struct meson8b_dwmac *dwmac, u32 reg,
106 				    u32 mask, u32 value)
107 {
108 	u32 data;
109 
110 	data = readl(dwmac->regs + reg);
111 	data &= ~mask;
112 	data |= (value & mask);
113 
114 	writel(data, dwmac->regs + reg);
115 }
116 
117 static struct clk *meson8b_dwmac_register_clk(struct meson8b_dwmac *dwmac,
118 					      const char *name_suffix,
119 					      const struct clk_parent_data *parents,
120 					      int num_parents,
121 					      const struct clk_ops *ops,
122 					      struct clk_hw *hw)
123 {
124 	struct clk_init_data init = { };
125 	char clk_name[32];
126 
127 	snprintf(clk_name, sizeof(clk_name), "%s#%s", dev_name(dwmac->dev),
128 		 name_suffix);
129 
130 	init.name = clk_name;
131 	init.ops = ops;
132 	init.flags = CLK_SET_RATE_PARENT;
133 	init.parent_data = parents;
134 	init.num_parents = num_parents;
135 
136 	hw->init = &init;
137 
138 	return devm_clk_register(dwmac->dev, hw);
139 }
140 
141 static int meson8b_init_rgmii_tx_clk(struct meson8b_dwmac *dwmac)
142 {
143 	struct clk *clk;
144 	struct device *dev = dwmac->dev;
145 	static const struct clk_parent_data mux_parents[] = {
146 		{ .fw_name = "clkin0", },
147 		{ .index = -1, },
148 	};
149 	static const struct clk_div_table div_table[] = {
150 		{ .div = 2, .val = 2, },
151 		{ .div = 3, .val = 3, },
152 		{ .div = 4, .val = 4, },
153 		{ .div = 5, .val = 5, },
154 		{ .div = 6, .val = 6, },
155 		{ .div = 7, .val = 7, },
156 		{ /* end of array */ }
157 	};
158 	struct meson8b_dwmac_clk_configs *clk_configs;
159 	struct clk_parent_data parent_data = { };
160 
161 	clk_configs = devm_kzalloc(dev, sizeof(*clk_configs), GFP_KERNEL);
162 	if (!clk_configs)
163 		return -ENOMEM;
164 
165 	clk_configs->m250_mux.reg = dwmac->regs + PRG_ETH0;
166 	clk_configs->m250_mux.shift = __ffs(PRG_ETH0_CLK_M250_SEL_MASK);
167 	clk_configs->m250_mux.mask = PRG_ETH0_CLK_M250_SEL_MASK >>
168 				     clk_configs->m250_mux.shift;
169 	clk = meson8b_dwmac_register_clk(dwmac, "m250_sel", mux_parents,
170 					 ARRAY_SIZE(mux_parents), &clk_mux_ops,
171 					 &clk_configs->m250_mux.hw);
172 	if (WARN_ON(IS_ERR(clk)))
173 		return PTR_ERR(clk);
174 
175 	parent_data.hw = &clk_configs->m250_mux.hw;
176 	clk_configs->m250_div.reg = dwmac->regs + PRG_ETH0;
177 	clk_configs->m250_div.shift = PRG_ETH0_CLK_M250_DIV_SHIFT;
178 	clk_configs->m250_div.width = PRG_ETH0_CLK_M250_DIV_WIDTH;
179 	clk_configs->m250_div.table = div_table;
180 	clk_configs->m250_div.flags = CLK_DIVIDER_ALLOW_ZERO |
181 				      CLK_DIVIDER_ROUND_CLOSEST;
182 	clk = meson8b_dwmac_register_clk(dwmac, "m250_div", &parent_data, 1,
183 					 &clk_divider_ops,
184 					 &clk_configs->m250_div.hw);
185 	if (WARN_ON(IS_ERR(clk)))
186 		return PTR_ERR(clk);
187 
188 	parent_data.hw = &clk_configs->m250_div.hw;
189 	clk_configs->fixed_div2.mult = 1;
190 	clk_configs->fixed_div2.div = 2;
191 	clk = meson8b_dwmac_register_clk(dwmac, "fixed_div2", &parent_data, 1,
192 					 &clk_fixed_factor_ops,
193 					 &clk_configs->fixed_div2.hw);
194 	if (WARN_ON(IS_ERR(clk)))
195 		return PTR_ERR(clk);
196 
197 	parent_data.hw = &clk_configs->fixed_div2.hw;
198 	clk_configs->rgmii_tx_en.reg = dwmac->regs + PRG_ETH0;
199 	clk_configs->rgmii_tx_en.bit_idx = PRG_ETH0_RGMII_TX_CLK_EN;
200 	clk = meson8b_dwmac_register_clk(dwmac, "rgmii_tx_en", &parent_data, 1,
201 					 &clk_gate_ops,
202 					 &clk_configs->rgmii_tx_en.hw);
203 	if (WARN_ON(IS_ERR(clk)))
204 		return PTR_ERR(clk);
205 
206 	dwmac->rgmii_tx_clk = clk;
207 
208 	return 0;
209 }
210 
211 static int meson8b_set_phy_mode(struct meson8b_dwmac *dwmac)
212 {
213 	switch (dwmac->phy_mode) {
214 	case PHY_INTERFACE_MODE_RGMII:
215 	case PHY_INTERFACE_MODE_RGMII_RXID:
216 	case PHY_INTERFACE_MODE_RGMII_ID:
217 	case PHY_INTERFACE_MODE_RGMII_TXID:
218 		/* enable RGMII mode */
219 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
220 					PRG_ETH0_RGMII_MODE,
221 					PRG_ETH0_RGMII_MODE);
222 		break;
223 	case PHY_INTERFACE_MODE_RMII:
224 		/* disable RGMII mode -> enables RMII mode */
225 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
226 					PRG_ETH0_RGMII_MODE, 0);
227 		break;
228 	default:
229 		dev_err(dwmac->dev, "fail to set phy-mode %s\n",
230 			phy_modes(dwmac->phy_mode));
231 		return -EINVAL;
232 	}
233 
234 	return 0;
235 }
236 
237 static int meson_axg_set_phy_mode(struct meson8b_dwmac *dwmac)
238 {
239 	int phy_intf_sel;
240 
241 	phy_intf_sel = stmmac_get_phy_intf_sel(dwmac->phy_mode);
242 	if (phy_intf_sel != PHY_INTF_SEL_RGMII &&
243 	    phy_intf_sel != PHY_INTF_SEL_RMII) {
244 		dev_err(dwmac->dev, "fail to set phy-mode %s\n",
245 			phy_modes(dwmac->phy_mode));
246 		return phy_intf_sel < 0 ? phy_intf_sel : -EINVAL;
247 	}
248 
249 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_EXT_PHY_MODE_MASK,
250 				FIELD_PREP(PRG_ETH0_EXT_PHY_MODE_MASK,
251 					   phy_intf_sel));
252 
253 	return 0;
254 }
255 
256 static void meson8b_clk_disable_unprepare(void *data)
257 {
258 	clk_disable_unprepare(data);
259 }
260 
261 static int meson8b_devm_clk_prepare_enable(struct meson8b_dwmac *dwmac,
262 					   struct clk *clk)
263 {
264 	int ret;
265 
266 	ret = clk_prepare_enable(clk);
267 	if (ret)
268 		return ret;
269 
270 	return devm_add_action_or_reset(dwmac->dev,
271 					meson8b_clk_disable_unprepare, clk);
272 }
273 
274 static int meson8b_init_rgmii_delays(struct meson8b_dwmac *dwmac)
275 {
276 	u32 tx_dly_config, rx_adj_config, cfg_rxclk_dly, delay_config;
277 	int ret;
278 
279 	rx_adj_config = 0;
280 	cfg_rxclk_dly = 0;
281 	tx_dly_config = FIELD_PREP(PRG_ETH0_TXDLY_MASK,
282 				   dwmac->tx_delay_ns >> 1);
283 
284 	if (dwmac->data->has_prg_eth1_rgmii_rx_delay)
285 		cfg_rxclk_dly = FIELD_PREP(PRG_ETH1_CFG_RXCLK_DLY,
286 					   dwmac->rx_delay_ps / 200);
287 	else if (dwmac->rx_delay_ps == 2000)
288 		rx_adj_config = PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP;
289 
290 	switch (dwmac->phy_mode) {
291 	case PHY_INTERFACE_MODE_RGMII:
292 		delay_config = tx_dly_config | rx_adj_config;
293 		break;
294 	case PHY_INTERFACE_MODE_RGMII_RXID:
295 		delay_config = tx_dly_config;
296 		cfg_rxclk_dly = 0;
297 		break;
298 	case PHY_INTERFACE_MODE_RGMII_TXID:
299 		delay_config = rx_adj_config;
300 		break;
301 	case PHY_INTERFACE_MODE_RGMII_ID:
302 	case PHY_INTERFACE_MODE_RMII:
303 		delay_config = 0;
304 		cfg_rxclk_dly = 0;
305 		break;
306 	default:
307 		dev_err(dwmac->dev, "unsupported phy-mode %s\n",
308 			phy_modes(dwmac->phy_mode));
309 		return -EINVAL;
310 	}
311 
312 	if (delay_config & PRG_ETH0_ADJ_ENABLE) {
313 		if (!dwmac->timing_adj_clk) {
314 			dev_err(dwmac->dev,
315 				"The timing-adjustment clock is mandatory for the RX delay re-timing\n");
316 			return -EINVAL;
317 		}
318 
319 		/* The timing adjustment logic is driven by a separate clock */
320 		ret = meson8b_devm_clk_prepare_enable(dwmac,
321 						      dwmac->timing_adj_clk);
322 		if (ret) {
323 			dev_err(dwmac->dev,
324 				"Failed to enable the timing-adjustment clock\n");
325 			return ret;
326 		}
327 	}
328 
329 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK |
330 				PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP |
331 				PRG_ETH0_ADJ_DELAY | PRG_ETH0_ADJ_SKEW,
332 				delay_config);
333 
334 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH1, PRG_ETH1_CFG_RXCLK_DLY,
335 				cfg_rxclk_dly);
336 
337 	return 0;
338 }
339 
340 static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
341 {
342 	int ret;
343 
344 	if (phy_interface_mode_is_rgmii(dwmac->phy_mode)) {
345 		/* only relevant for RMII mode -> disable in RGMII mode */
346 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
347 					PRG_ETH0_INVERTED_RMII_CLK, 0);
348 
349 		/* Configure the 125MHz RGMII TX clock, the IP block changes
350 		 * the output automatically (= without us having to configure
351 		 * a register) based on the line-speed (125MHz for Gbit speeds,
352 		 * 25MHz for 100Mbit/s and 2.5MHz for 10Mbit/s).
353 		 */
354 		ret = clk_set_rate(dwmac->rgmii_tx_clk, 125 * 1000 * 1000);
355 		if (ret) {
356 			dev_err(dwmac->dev,
357 				"failed to set RGMII TX clock\n");
358 			return ret;
359 		}
360 
361 		ret = meson8b_devm_clk_prepare_enable(dwmac,
362 						      dwmac->rgmii_tx_clk);
363 		if (ret) {
364 			dev_err(dwmac->dev,
365 				"failed to enable the RGMII TX clock\n");
366 			return ret;
367 		}
368 	} else {
369 		/* invert internal clk_rmii_i to generate 25/2.5 tx_rx_clk */
370 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
371 					PRG_ETH0_INVERTED_RMII_CLK,
372 					PRG_ETH0_INVERTED_RMII_CLK);
373 	}
374 
375 	/* enable TX_CLK and PHY_REF_CLK generator */
376 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TX_AND_PHY_REF_CLK,
377 				PRG_ETH0_TX_AND_PHY_REF_CLK);
378 
379 	return 0;
380 }
381 
382 static int meson8b_dwmac_probe(struct platform_device *pdev)
383 {
384 	struct plat_stmmacenet_data *plat_dat;
385 	struct stmmac_resources stmmac_res;
386 	struct meson8b_dwmac *dwmac;
387 	int ret;
388 
389 	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
390 	if (ret)
391 		return ret;
392 
393 	plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
394 	if (IS_ERR(plat_dat))
395 		return PTR_ERR(plat_dat);
396 
397 	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
398 	if (!dwmac)
399 		return -ENOMEM;
400 
401 	dwmac->data = (const struct meson8b_dwmac_data *)
402 		of_device_get_match_data(&pdev->dev);
403 	if (!dwmac->data)
404 		return -EINVAL;
405 	dwmac->regs = devm_platform_ioremap_resource(pdev, 1);
406 	if (IS_ERR(dwmac->regs))
407 		return PTR_ERR(dwmac->regs);
408 
409 	dwmac->dev = &pdev->dev;
410 	dwmac->phy_mode = plat_dat->phy_interface;
411 
412 	/* use 2ns as fallback since this value was previously hardcoded */
413 	if (of_property_read_u32(pdev->dev.of_node, "amlogic,tx-delay-ns",
414 				 &dwmac->tx_delay_ns))
415 		dwmac->tx_delay_ns = 2;
416 
417 	/* RX delay defaults to 0ps since this is what many boards use */
418 	if (of_property_read_u32(pdev->dev.of_node, "rx-internal-delay-ps",
419 				 &dwmac->rx_delay_ps)) {
420 		if (!of_property_read_u32(pdev->dev.of_node,
421 					  "amlogic,rx-delay-ns",
422 					  &dwmac->rx_delay_ps))
423 			/* convert ns to ps */
424 			dwmac->rx_delay_ps *= 1000;
425 	}
426 
427 	if (dwmac->data->has_prg_eth1_rgmii_rx_delay) {
428 		if (dwmac->rx_delay_ps > 3000 || dwmac->rx_delay_ps % 200) {
429 			dev_err(dwmac->dev,
430 				"The RGMII RX delay range is 0..3000ps in 200ps steps");
431 			return -EINVAL;
432 		}
433 	} else {
434 		if (dwmac->rx_delay_ps != 0 && dwmac->rx_delay_ps != 2000) {
435 			dev_err(dwmac->dev,
436 				"The only allowed RGMII RX delays values are: 0ps, 2000ps");
437 			return -EINVAL;
438 		}
439 	}
440 
441 	dwmac->timing_adj_clk = devm_clk_get_optional(dwmac->dev,
442 						      "timing-adjustment");
443 	if (IS_ERR(dwmac->timing_adj_clk))
444 		return PTR_ERR(dwmac->timing_adj_clk);
445 
446 	ret = meson8b_init_rgmii_delays(dwmac);
447 	if (ret)
448 		return ret;
449 
450 	ret = meson8b_init_rgmii_tx_clk(dwmac);
451 	if (ret)
452 		return ret;
453 
454 	ret = dwmac->data->set_phy_mode(dwmac);
455 	if (ret)
456 		return ret;
457 
458 	ret = meson8b_init_prg_eth(dwmac);
459 	if (ret)
460 		return ret;
461 
462 	plat_dat->bsp_priv = dwmac;
463 
464 	return stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
465 }
466 
467 static const struct meson8b_dwmac_data meson8b_dwmac_data = {
468 	.set_phy_mode = meson8b_set_phy_mode,
469 	.has_prg_eth1_rgmii_rx_delay = false,
470 };
471 
472 static const struct meson8b_dwmac_data meson_axg_dwmac_data = {
473 	.set_phy_mode = meson_axg_set_phy_mode,
474 	.has_prg_eth1_rgmii_rx_delay = false,
475 };
476 
477 static const struct meson8b_dwmac_data meson_g12a_dwmac_data = {
478 	.set_phy_mode = meson_axg_set_phy_mode,
479 	.has_prg_eth1_rgmii_rx_delay = true,
480 };
481 
482 static const struct of_device_id meson8b_dwmac_match[] = {
483 	{
484 		.compatible = "amlogic,meson8b-dwmac",
485 		.data = &meson8b_dwmac_data,
486 	},
487 	{
488 		.compatible = "amlogic,meson8m2-dwmac",
489 		.data = &meson8b_dwmac_data,
490 	},
491 	{
492 		.compatible = "amlogic,meson-gxbb-dwmac",
493 		.data = &meson8b_dwmac_data,
494 	},
495 	{
496 		.compatible = "amlogic,meson-axg-dwmac",
497 		.data = &meson_axg_dwmac_data,
498 	},
499 	{
500 		.compatible = "amlogic,meson-g12a-dwmac",
501 		.data = &meson_g12a_dwmac_data,
502 	},
503 	{ }
504 };
505 MODULE_DEVICE_TABLE(of, meson8b_dwmac_match);
506 
507 static struct platform_driver meson8b_dwmac_driver = {
508 	.probe  = meson8b_dwmac_probe,
509 	.remove = stmmac_pltfr_remove,
510 	.driver = {
511 		.name           = "meson8b-dwmac",
512 		.pm		= &stmmac_pltfr_pm_ops,
513 		.of_match_table = meson8b_dwmac_match,
514 	},
515 };
516 module_platform_driver(meson8b_dwmac_driver);
517 
518 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
519 MODULE_DESCRIPTION("Amlogic Meson8b, Meson8m2 and GXBB DWMAC glue layer");
520 MODULE_LICENSE("GPL v2");
521