1 /*
2  * Amlogic Meson8b, Meson8m2 and GXBB DWMAC glue layer
3  *
4  * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
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  * You should have received a copy of the GNU General Public License
11  * along with this program. If not, see <http://www.gnu.org/licenses/>.
12  */
13 
14 #include <linux/clk.h>
15 #include <linux/clk-provider.h>
16 #include <linux/device.h>
17 #include <linux/ethtool.h>
18 #include <linux/io.h>
19 #include <linux/ioport.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/of_net.h>
23 #include <linux/mfd/syscon.h>
24 #include <linux/platform_device.h>
25 #include <linux/stmmac.h>
26 
27 #include "stmmac_platform.h"
28 
29 #define PRG_ETH0			0x0
30 
31 #define PRG_ETH0_RGMII_MODE		BIT(0)
32 
33 #define PRG_ETH0_EXT_PHY_MODE_MASK	GENMASK(2, 0)
34 #define PRG_ETH0_EXT_RGMII_MODE		1
35 #define PRG_ETH0_EXT_RMII_MODE		4
36 
37 /* mux to choose between fclk_div2 (bit unset) and mpll2 (bit set) */
38 #define PRG_ETH0_CLK_M250_SEL_SHIFT	4
39 #define PRG_ETH0_CLK_M250_SEL_MASK	GENMASK(4, 4)
40 
41 #define PRG_ETH0_TXDLY_SHIFT		5
42 #define PRG_ETH0_TXDLY_MASK		GENMASK(6, 5)
43 
44 /* divider for the result of m250_sel */
45 #define PRG_ETH0_CLK_M250_DIV_SHIFT	7
46 #define PRG_ETH0_CLK_M250_DIV_WIDTH	3
47 
48 #define PRG_ETH0_RGMII_TX_CLK_EN	10
49 
50 #define PRG_ETH0_INVERTED_RMII_CLK	BIT(11)
51 #define PRG_ETH0_TX_AND_PHY_REF_CLK	BIT(12)
52 
53 #define MUX_CLK_NUM_PARENTS		2
54 
55 struct meson8b_dwmac;
56 
57 struct meson8b_dwmac_data {
58 	int (*set_phy_mode)(struct meson8b_dwmac *dwmac);
59 };
60 
61 struct meson8b_dwmac {
62 	struct device			*dev;
63 	void __iomem			*regs;
64 
65 	const struct meson8b_dwmac_data	*data;
66 	phy_interface_t			phy_mode;
67 	struct clk			*rgmii_tx_clk;
68 	u32				tx_delay_ns;
69 };
70 
71 struct meson8b_dwmac_clk_configs {
72 	struct clk_mux		m250_mux;
73 	struct clk_divider	m250_div;
74 	struct clk_fixed_factor	fixed_div2;
75 	struct clk_gate		rgmii_tx_en;
76 };
77 
78 static void meson8b_dwmac_mask_bits(struct meson8b_dwmac *dwmac, u32 reg,
79 				    u32 mask, u32 value)
80 {
81 	u32 data;
82 
83 	data = readl(dwmac->regs + reg);
84 	data &= ~mask;
85 	data |= (value & mask);
86 
87 	writel(data, dwmac->regs + reg);
88 }
89 
90 static struct clk *meson8b_dwmac_register_clk(struct meson8b_dwmac *dwmac,
91 					      const char *name_suffix,
92 					      const char **parent_names,
93 					      int num_parents,
94 					      const struct clk_ops *ops,
95 					      struct clk_hw *hw)
96 {
97 	struct clk_init_data init;
98 	char clk_name[32];
99 
100 	snprintf(clk_name, sizeof(clk_name), "%s#%s", dev_name(dwmac->dev),
101 		 name_suffix);
102 
103 	init.name = clk_name;
104 	init.ops = ops;
105 	init.flags = CLK_SET_RATE_PARENT;
106 	init.parent_names = parent_names;
107 	init.num_parents = num_parents;
108 
109 	hw->init = &init;
110 
111 	return devm_clk_register(dwmac->dev, hw);
112 }
113 
114 static int meson8b_init_rgmii_tx_clk(struct meson8b_dwmac *dwmac)
115 {
116 	int i, ret;
117 	struct clk *clk;
118 	struct device *dev = dwmac->dev;
119 	const char *parent_name, *mux_parent_names[MUX_CLK_NUM_PARENTS];
120 	struct meson8b_dwmac_clk_configs *clk_configs;
121 
122 	clk_configs = devm_kzalloc(dev, sizeof(*clk_configs), GFP_KERNEL);
123 	if (!clk_configs)
124 		return -ENOMEM;
125 
126 	/* get the mux parents from DT */
127 	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
128 		char name[16];
129 
130 		snprintf(name, sizeof(name), "clkin%d", i);
131 		clk = devm_clk_get(dev, name);
132 		if (IS_ERR(clk)) {
133 			ret = PTR_ERR(clk);
134 			if (ret != -EPROBE_DEFER)
135 				dev_err(dev, "Missing clock %s\n", name);
136 			return ret;
137 		}
138 
139 		mux_parent_names[i] = __clk_get_name(clk);
140 	}
141 
142 	clk_configs->m250_mux.reg = dwmac->regs + PRG_ETH0;
143 	clk_configs->m250_mux.shift = PRG_ETH0_CLK_M250_SEL_SHIFT;
144 	clk_configs->m250_mux.mask = PRG_ETH0_CLK_M250_SEL_MASK;
145 	clk = meson8b_dwmac_register_clk(dwmac, "m250_sel", mux_parent_names,
146 					 MUX_CLK_NUM_PARENTS, &clk_mux_ops,
147 					 &clk_configs->m250_mux.hw);
148 	if (WARN_ON(IS_ERR(clk)))
149 		return PTR_ERR(clk);
150 
151 	parent_name = __clk_get_name(clk);
152 	clk_configs->m250_div.reg = dwmac->regs + PRG_ETH0;
153 	clk_configs->m250_div.shift = PRG_ETH0_CLK_M250_DIV_SHIFT;
154 	clk_configs->m250_div.width = PRG_ETH0_CLK_M250_DIV_WIDTH;
155 	clk_configs->m250_div.flags = CLK_DIVIDER_ONE_BASED |
156 				CLK_DIVIDER_ALLOW_ZERO |
157 				CLK_DIVIDER_ROUND_CLOSEST;
158 	clk = meson8b_dwmac_register_clk(dwmac, "m250_div", &parent_name, 1,
159 					 &clk_divider_ops,
160 					 &clk_configs->m250_div.hw);
161 	if (WARN_ON(IS_ERR(clk)))
162 		return PTR_ERR(clk);
163 
164 	parent_name = __clk_get_name(clk);
165 	clk_configs->fixed_div2.mult = 1;
166 	clk_configs->fixed_div2.div = 2;
167 	clk = meson8b_dwmac_register_clk(dwmac, "fixed_div2", &parent_name, 1,
168 					 &clk_fixed_factor_ops,
169 					 &clk_configs->fixed_div2.hw);
170 	if (WARN_ON(IS_ERR(clk)))
171 		return PTR_ERR(clk);
172 
173 	parent_name = __clk_get_name(clk);
174 	clk_configs->rgmii_tx_en.reg = dwmac->regs + PRG_ETH0;
175 	clk_configs->rgmii_tx_en.bit_idx = PRG_ETH0_RGMII_TX_CLK_EN;
176 	clk = meson8b_dwmac_register_clk(dwmac, "rgmii_tx_en", &parent_name, 1,
177 					 &clk_gate_ops,
178 					 &clk_configs->rgmii_tx_en.hw);
179 	if (WARN_ON(IS_ERR(clk)))
180 		return PTR_ERR(clk);
181 
182 	dwmac->rgmii_tx_clk = clk;
183 
184 	return 0;
185 }
186 
187 static int meson8b_set_phy_mode(struct meson8b_dwmac *dwmac)
188 {
189 	switch (dwmac->phy_mode) {
190 	case PHY_INTERFACE_MODE_RGMII:
191 	case PHY_INTERFACE_MODE_RGMII_RXID:
192 	case PHY_INTERFACE_MODE_RGMII_ID:
193 	case PHY_INTERFACE_MODE_RGMII_TXID:
194 		/* enable RGMII mode */
195 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
196 					PRG_ETH0_RGMII_MODE,
197 					PRG_ETH0_RGMII_MODE);
198 		break;
199 	case PHY_INTERFACE_MODE_RMII:
200 		/* disable RGMII mode -> enables RMII mode */
201 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
202 					PRG_ETH0_RGMII_MODE, 0);
203 		break;
204 	default:
205 		dev_err(dwmac->dev, "fail to set phy-mode %s\n",
206 			phy_modes(dwmac->phy_mode));
207 		return -EINVAL;
208 	}
209 
210 	return 0;
211 }
212 
213 static int meson_axg_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_EXT_PHY_MODE_MASK,
223 					PRG_ETH0_EXT_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_EXT_PHY_MODE_MASK,
229 					PRG_ETH0_EXT_RMII_MODE);
230 		break;
231 	default:
232 		dev_err(dwmac->dev, "fail to set phy-mode %s\n",
233 			phy_modes(dwmac->phy_mode));
234 		return -EINVAL;
235 	}
236 
237 	return 0;
238 }
239 
240 static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
241 {
242 	int ret;
243 	u8 tx_dly_val = 0;
244 
245 	switch (dwmac->phy_mode) {
246 	case PHY_INTERFACE_MODE_RGMII:
247 	case PHY_INTERFACE_MODE_RGMII_RXID:
248 		/* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where
249 		 * 8ns are exactly one cycle of the 125MHz RGMII TX clock):
250 		 * 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3
251 		 */
252 		tx_dly_val = dwmac->tx_delay_ns >> 1;
253 		/* fall through */
254 
255 	case PHY_INTERFACE_MODE_RGMII_ID:
256 	case PHY_INTERFACE_MODE_RGMII_TXID:
257 		/* only relevant for RMII mode -> disable in RGMII mode */
258 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
259 					PRG_ETH0_INVERTED_RMII_CLK, 0);
260 
261 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK,
262 					tx_dly_val << PRG_ETH0_TXDLY_SHIFT);
263 
264 		/* Configure the 125MHz RGMII TX clock, the IP block changes
265 		 * the output automatically (= without us having to configure
266 		 * a register) based on the line-speed (125MHz for Gbit speeds,
267 		 * 25MHz for 100Mbit/s and 2.5MHz for 10Mbit/s).
268 		 */
269 		ret = clk_set_rate(dwmac->rgmii_tx_clk, 125 * 1000 * 1000);
270 		if (ret) {
271 			dev_err(dwmac->dev,
272 				"failed to set RGMII TX clock\n");
273 			return ret;
274 		}
275 
276 		ret = clk_prepare_enable(dwmac->rgmii_tx_clk);
277 		if (ret) {
278 			dev_err(dwmac->dev,
279 				"failed to enable the RGMII TX clock\n");
280 			return ret;
281 		}
282 
283 		devm_add_action_or_reset(dwmac->dev,
284 					(void(*)(void *))clk_disable_unprepare,
285 					dwmac->rgmii_tx_clk);
286 		break;
287 
288 	case PHY_INTERFACE_MODE_RMII:
289 		/* invert internal clk_rmii_i to generate 25/2.5 tx_rx_clk */
290 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
291 					PRG_ETH0_INVERTED_RMII_CLK,
292 					PRG_ETH0_INVERTED_RMII_CLK);
293 
294 		/* TX clock delay cannot be configured in RMII mode */
295 		meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK,
296 					0);
297 
298 		break;
299 
300 	default:
301 		dev_err(dwmac->dev, "unsupported phy-mode %s\n",
302 			phy_modes(dwmac->phy_mode));
303 		return -EINVAL;
304 	}
305 
306 	/* enable TX_CLK and PHY_REF_CLK generator */
307 	meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TX_AND_PHY_REF_CLK,
308 				PRG_ETH0_TX_AND_PHY_REF_CLK);
309 
310 	return 0;
311 }
312 
313 static int meson8b_dwmac_probe(struct platform_device *pdev)
314 {
315 	struct plat_stmmacenet_data *plat_dat;
316 	struct stmmac_resources stmmac_res;
317 	struct resource *res;
318 	struct meson8b_dwmac *dwmac;
319 	int ret;
320 
321 	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
322 	if (ret)
323 		return ret;
324 
325 	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
326 	if (IS_ERR(plat_dat))
327 		return PTR_ERR(plat_dat);
328 
329 	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
330 	if (!dwmac) {
331 		ret = -ENOMEM;
332 		goto err_remove_config_dt;
333 	}
334 
335 	dwmac->data = (const struct meson8b_dwmac_data *)
336 		of_device_get_match_data(&pdev->dev);
337 	if (!dwmac->data) {
338 		ret = -EINVAL;
339 		goto err_remove_config_dt;
340 	}
341 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
342 	dwmac->regs = devm_ioremap_resource(&pdev->dev, res);
343 	if (IS_ERR(dwmac->regs)) {
344 		ret = PTR_ERR(dwmac->regs);
345 		goto err_remove_config_dt;
346 	}
347 
348 	dwmac->dev = &pdev->dev;
349 	dwmac->phy_mode = of_get_phy_mode(pdev->dev.of_node);
350 	if (dwmac->phy_mode < 0) {
351 		dev_err(&pdev->dev, "missing phy-mode property\n");
352 		ret = -EINVAL;
353 		goto err_remove_config_dt;
354 	}
355 
356 	/* use 2ns as fallback since this value was previously hardcoded */
357 	if (of_property_read_u32(pdev->dev.of_node, "amlogic,tx-delay-ns",
358 				 &dwmac->tx_delay_ns))
359 		dwmac->tx_delay_ns = 2;
360 
361 	ret = meson8b_init_rgmii_tx_clk(dwmac);
362 	if (ret)
363 		goto err_remove_config_dt;
364 
365 	ret = dwmac->data->set_phy_mode(dwmac);
366 	if (ret)
367 		goto err_remove_config_dt;
368 
369 	ret = meson8b_init_prg_eth(dwmac);
370 	if (ret)
371 		goto err_remove_config_dt;
372 
373 	plat_dat->bsp_priv = dwmac;
374 
375 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
376 	if (ret)
377 		goto err_remove_config_dt;
378 
379 	return 0;
380 
381 err_remove_config_dt:
382 	stmmac_remove_config_dt(pdev, plat_dat);
383 
384 	return ret;
385 }
386 
387 static const struct meson8b_dwmac_data meson8b_dwmac_data = {
388 	.set_phy_mode = meson8b_set_phy_mode,
389 };
390 
391 static const struct meson8b_dwmac_data meson_axg_dwmac_data = {
392 	.set_phy_mode = meson_axg_set_phy_mode,
393 };
394 
395 static const struct of_device_id meson8b_dwmac_match[] = {
396 	{
397 		.compatible = "amlogic,meson8b-dwmac",
398 		.data = &meson8b_dwmac_data,
399 	},
400 	{
401 		.compatible = "amlogic,meson8m2-dwmac",
402 		.data = &meson8b_dwmac_data,
403 	},
404 	{
405 		.compatible = "amlogic,meson-gxbb-dwmac",
406 		.data = &meson8b_dwmac_data,
407 	},
408 	{
409 		.compatible = "amlogic,meson-axg-dwmac",
410 		.data = &meson_axg_dwmac_data,
411 	},
412 	{ }
413 };
414 MODULE_DEVICE_TABLE(of, meson8b_dwmac_match);
415 
416 static struct platform_driver meson8b_dwmac_driver = {
417 	.probe  = meson8b_dwmac_probe,
418 	.remove = stmmac_pltfr_remove,
419 	.driver = {
420 		.name           = "meson8b-dwmac",
421 		.pm		= &stmmac_pltfr_pm_ops,
422 		.of_match_table = meson8b_dwmac_match,
423 	},
424 };
425 module_platform_driver(meson8b_dwmac_driver);
426 
427 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
428 MODULE_DESCRIPTION("Amlogic Meson8b, Meson8m2 and GXBB DWMAC glue layer");
429 MODULE_LICENSE("GPL v2");
430