1 /*
2  * dwmac-sti.c - STMicroelectronics DWMAC Specific Glue layer
3  *
4  * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
5  * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
6  * Contributors: Giuseppe Cavallaro <peppe.cavallaro@st.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/platform_device.h>
17 #include <linux/stmmac.h>
18 #include <linux/phy.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/regmap.h>
21 #include <linux/clk.h>
22 #include <linux/of.h>
23 #include <linux/of_net.h>
24 
25 #include "stmmac_platform.h"
26 
27 #define DWMAC_125MHZ	125000000
28 #define DWMAC_50MHZ	50000000
29 #define DWMAC_25MHZ	25000000
30 #define DWMAC_2_5MHZ	2500000
31 
32 #define IS_PHY_IF_MODE_RGMII(iface)	(iface == PHY_INTERFACE_MODE_RGMII || \
33 			iface == PHY_INTERFACE_MODE_RGMII_ID || \
34 			iface == PHY_INTERFACE_MODE_RGMII_RXID || \
35 			iface == PHY_INTERFACE_MODE_RGMII_TXID)
36 
37 #define IS_PHY_IF_MODE_GBIT(iface)	(IS_PHY_IF_MODE_RGMII(iface) || \
38 					 iface == PHY_INTERFACE_MODE_GMII)
39 
40 /* STiH4xx register definitions (STiH415/STiH416/STiH407/STiH410 families)
41  *
42  * Below table summarizes the clock requirement and clock sources for
43  * supported phy interface modes with link speeds.
44  * ________________________________________________
45  *|  PHY_MODE	| 1000 Mbit Link | 100 Mbit Link   |
46  * ------------------------------------------------
47  *|	MII	|	n/a	 |	25Mhz	   |
48  *|		|		 |	txclk	   |
49  * ------------------------------------------------
50  *|	GMII	|     125Mhz	 |	25Mhz	   |
51  *|		|  clk-125/txclk |	txclk	   |
52  * ------------------------------------------------
53  *|	RGMII	|     125Mhz	 |	25Mhz	   |
54  *|		|  clk-125/txclk |	clkgen     |
55  *|		|    clkgen	 |		   |
56  * ------------------------------------------------
57  *|	RMII	|	n/a	 |	25Mhz	   |
58  *|		|		 |clkgen/phyclk-in |
59  * ------------------------------------------------
60  *
61  *	  Register Configuration
62  *-------------------------------
63  * src	 |BIT(8)| BIT(7)| BIT(6)|
64  *-------------------------------
65  * txclk |   0	|  n/a	|   1	|
66  *-------------------------------
67  * ck_125|   0	|  n/a	|   0	|
68  *-------------------------------
69  * phyclk|   1	|   0	|  n/a	|
70  *-------------------------------
71  * clkgen|   1	|   1	|  n/a	|
72  *-------------------------------
73  */
74 
75 #define STIH4XX_RETIME_SRC_MASK			GENMASK(8, 6)
76 #define STIH4XX_ETH_SEL_TX_RETIME_CLK		BIT(8)
77 #define STIH4XX_ETH_SEL_INTERNAL_NOTEXT_PHYCLK	BIT(7)
78 #define STIH4XX_ETH_SEL_TXCLK_NOT_CLK125	BIT(6)
79 
80 /* STiD127 register definitions
81  *-----------------------
82  * src	 |BIT(6)| BIT(7)|
83  *-----------------------
84  * MII   |  1	|   n/a	|
85  *-----------------------
86  * RMII  |  n/a	|   1	|
87  * clkgen|	|	|
88  *-----------------------
89  * RMII  |  n/a	|   0	|
90  * phyclk|	|	|
91  *-----------------------
92  * RGMII |  1	|  n/a	|
93  * clkgen|	|	|
94  *-----------------------
95  */
96 
97 #define STID127_RETIME_SRC_MASK			GENMASK(7, 6)
98 #define STID127_ETH_SEL_INTERNAL_NOTEXT_PHYCLK	BIT(7)
99 #define STID127_ETH_SEL_INTERNAL_NOTEXT_TXCLK	BIT(6)
100 
101 #define ENMII_MASK	GENMASK(5, 5)
102 #define ENMII		BIT(5)
103 #define EN_MASK		GENMASK(1, 1)
104 #define EN		BIT(1)
105 
106 /*
107  * 3 bits [4:2]
108  *	000-GMII/MII
109  *	001-RGMII
110  *	010-SGMII
111  *	100-RMII
112  */
113 #define MII_PHY_SEL_MASK	GENMASK(4, 2)
114 #define ETH_PHY_SEL_RMII	BIT(4)
115 #define ETH_PHY_SEL_SGMII	BIT(3)
116 #define ETH_PHY_SEL_RGMII	BIT(2)
117 #define ETH_PHY_SEL_GMII	0x0
118 #define ETH_PHY_SEL_MII		0x0
119 
120 struct sti_dwmac {
121 	int interface;		/* MII interface */
122 	bool ext_phyclk;	/* Clock from external PHY */
123 	u32 tx_retime_src;	/* TXCLK Retiming*/
124 	struct clk *clk;	/* PHY clock */
125 	int ctrl_reg;		/* GMAC glue-logic control register */
126 	int clk_sel_reg;	/* GMAC ext clk selection register */
127 	struct device *dev;
128 	struct regmap *regmap;
129 	u32 speed;
130 };
131 
132 static u32 phy_intf_sels[] = {
133 	[PHY_INTERFACE_MODE_MII] = ETH_PHY_SEL_MII,
134 	[PHY_INTERFACE_MODE_GMII] = ETH_PHY_SEL_GMII,
135 	[PHY_INTERFACE_MODE_RGMII] = ETH_PHY_SEL_RGMII,
136 	[PHY_INTERFACE_MODE_RGMII_ID] = ETH_PHY_SEL_RGMII,
137 	[PHY_INTERFACE_MODE_SGMII] = ETH_PHY_SEL_SGMII,
138 	[PHY_INTERFACE_MODE_RMII] = ETH_PHY_SEL_RMII,
139 };
140 
141 enum {
142 	TX_RETIME_SRC_NA = 0,
143 	TX_RETIME_SRC_TXCLK = 1,
144 	TX_RETIME_SRC_CLK_125,
145 	TX_RETIME_SRC_PHYCLK,
146 	TX_RETIME_SRC_CLKGEN,
147 };
148 
149 static u32 stih4xx_tx_retime_val[] = {
150 	[TX_RETIME_SRC_TXCLK] = STIH4XX_ETH_SEL_TXCLK_NOT_CLK125,
151 	[TX_RETIME_SRC_CLK_125] = 0x0,
152 	[TX_RETIME_SRC_PHYCLK] = STIH4XX_ETH_SEL_TX_RETIME_CLK,
153 	[TX_RETIME_SRC_CLKGEN] = STIH4XX_ETH_SEL_TX_RETIME_CLK
154 				 | STIH4XX_ETH_SEL_INTERNAL_NOTEXT_PHYCLK,
155 };
156 
157 static void stih4xx_fix_retime_src(void *priv, u32 spd)
158 {
159 	struct sti_dwmac *dwmac = priv;
160 	u32 src = dwmac->tx_retime_src;
161 	u32 reg = dwmac->ctrl_reg;
162 	u32 freq = 0;
163 
164 	if (dwmac->interface == PHY_INTERFACE_MODE_MII) {
165 		src = TX_RETIME_SRC_TXCLK;
166 	} else if (dwmac->interface == PHY_INTERFACE_MODE_RMII) {
167 		if (dwmac->ext_phyclk) {
168 			src = TX_RETIME_SRC_PHYCLK;
169 		} else {
170 			src = TX_RETIME_SRC_CLKGEN;
171 			freq = DWMAC_50MHZ;
172 		}
173 	} else if (IS_PHY_IF_MODE_RGMII(dwmac->interface)) {
174 		/* On GiGa clk source can be either ext or from clkgen */
175 		if (spd == SPEED_1000) {
176 			freq = DWMAC_125MHZ;
177 		} else {
178 			/* Switch to clkgen for these speeds */
179 			src = TX_RETIME_SRC_CLKGEN;
180 			if (spd == SPEED_100)
181 				freq = DWMAC_25MHZ;
182 			else if (spd == SPEED_10)
183 				freq = DWMAC_2_5MHZ;
184 		}
185 	}
186 
187 	if (src == TX_RETIME_SRC_CLKGEN && dwmac->clk && freq)
188 		clk_set_rate(dwmac->clk, freq);
189 
190 	regmap_update_bits(dwmac->regmap, reg, STIH4XX_RETIME_SRC_MASK,
191 			   stih4xx_tx_retime_val[src]);
192 }
193 
194 static void stid127_fix_retime_src(void *priv, u32 spd)
195 {
196 	struct sti_dwmac *dwmac = priv;
197 	u32 reg = dwmac->ctrl_reg;
198 	u32 freq = 0;
199 	u32 val = 0;
200 
201 	if (dwmac->interface == PHY_INTERFACE_MODE_MII) {
202 		val = STID127_ETH_SEL_INTERNAL_NOTEXT_TXCLK;
203 	} else if (dwmac->interface == PHY_INTERFACE_MODE_RMII) {
204 		if (!dwmac->ext_phyclk) {
205 			val = STID127_ETH_SEL_INTERNAL_NOTEXT_PHYCLK;
206 			freq = DWMAC_50MHZ;
207 		}
208 	} else if (IS_PHY_IF_MODE_RGMII(dwmac->interface)) {
209 		val = STID127_ETH_SEL_INTERNAL_NOTEXT_TXCLK;
210 		if (spd == SPEED_1000)
211 			freq = DWMAC_125MHZ;
212 		else if (spd == SPEED_100)
213 			freq = DWMAC_25MHZ;
214 		else if (spd == SPEED_10)
215 			freq = DWMAC_2_5MHZ;
216 	}
217 
218 	if (dwmac->clk && freq)
219 		clk_set_rate(dwmac->clk, freq);
220 
221 	regmap_update_bits(dwmac->regmap, reg, STID127_RETIME_SRC_MASK, val);
222 }
223 
224 static void sti_dwmac_ctrl_init(struct sti_dwmac *dwmac)
225 {
226 	struct regmap *regmap = dwmac->regmap;
227 	int iface = dwmac->interface;
228 	struct device *dev = dwmac->dev;
229 	struct device_node *np = dev->of_node;
230 	u32 reg = dwmac->ctrl_reg;
231 	u32 val;
232 
233 	if (dwmac->clk)
234 		clk_prepare_enable(dwmac->clk);
235 
236 	if (of_property_read_bool(np, "st,gmac_en"))
237 		regmap_update_bits(regmap, reg, EN_MASK, EN);
238 
239 	regmap_update_bits(regmap, reg, MII_PHY_SEL_MASK, phy_intf_sels[iface]);
240 
241 	val = (iface == PHY_INTERFACE_MODE_REVMII) ? 0 : ENMII;
242 	regmap_update_bits(regmap, reg, ENMII_MASK, val);
243 }
244 
245 static int stix4xx_init(struct platform_device *pdev, void *priv)
246 {
247 	struct sti_dwmac *dwmac = priv;
248 	u32 spd = dwmac->speed;
249 
250 	sti_dwmac_ctrl_init(dwmac);
251 
252 	stih4xx_fix_retime_src(priv, spd);
253 
254 	return 0;
255 }
256 
257 static int stid127_init(struct platform_device *pdev, void *priv)
258 {
259 	struct sti_dwmac *dwmac = priv;
260 	u32 spd = dwmac->speed;
261 
262 	sti_dwmac_ctrl_init(dwmac);
263 
264 	stid127_fix_retime_src(priv, spd);
265 
266 	return 0;
267 }
268 
269 static void sti_dwmac_exit(struct platform_device *pdev, void *priv)
270 {
271 	struct sti_dwmac *dwmac = priv;
272 
273 	if (dwmac->clk)
274 		clk_disable_unprepare(dwmac->clk);
275 }
276 static int sti_dwmac_parse_data(struct sti_dwmac *dwmac,
277 				struct platform_device *pdev)
278 {
279 	struct resource *res;
280 	struct device *dev = &pdev->dev;
281 	struct device_node *np = dev->of_node;
282 	struct regmap *regmap;
283 	int err;
284 
285 	if (!np)
286 		return -EINVAL;
287 
288 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sti-ethconf");
289 	if (!res)
290 		return -ENODATA;
291 	dwmac->ctrl_reg = res->start;
292 
293 	/* clk selection from extra syscfg register */
294 	dwmac->clk_sel_reg = -ENXIO;
295 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sti-clkconf");
296 	if (res)
297 		dwmac->clk_sel_reg = res->start;
298 
299 	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscon");
300 	if (IS_ERR(regmap))
301 		return PTR_ERR(regmap);
302 
303 	dwmac->dev = dev;
304 	dwmac->interface = of_get_phy_mode(np);
305 	dwmac->regmap = regmap;
306 	dwmac->ext_phyclk = of_property_read_bool(np, "st,ext-phyclk");
307 	dwmac->tx_retime_src = TX_RETIME_SRC_NA;
308 	dwmac->speed = SPEED_100;
309 
310 	if (IS_PHY_IF_MODE_GBIT(dwmac->interface)) {
311 		const char *rs;
312 
313 		err = of_property_read_string(np, "st,tx-retime-src", &rs);
314 		if (err < 0) {
315 			dev_warn(dev, "Use internal clock source\n");
316 			dwmac->tx_retime_src = TX_RETIME_SRC_CLKGEN;
317 		} else if (!strcasecmp(rs, "clk_125")) {
318 			dwmac->tx_retime_src = TX_RETIME_SRC_CLK_125;
319 		} else if (!strcasecmp(rs, "txclk")) {
320 			dwmac->tx_retime_src = TX_RETIME_SRC_TXCLK;
321 		}
322 
323 		dwmac->speed = SPEED_1000;
324 	}
325 
326 	dwmac->clk = devm_clk_get(dev, "sti-ethclk");
327 	if (IS_ERR(dwmac->clk)) {
328 		dev_warn(dev, "No phy clock provided...\n");
329 		dwmac->clk = NULL;
330 	}
331 
332 	return 0;
333 }
334 
335 static void *sti_dwmac_setup(struct platform_device *pdev)
336 {
337 	struct sti_dwmac *dwmac;
338 	int ret;
339 
340 	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
341 	if (!dwmac)
342 		return ERR_PTR(-ENOMEM);
343 
344 	ret = sti_dwmac_parse_data(dwmac, pdev);
345 	if (ret) {
346 		dev_err(&pdev->dev, "Unable to parse OF data\n");
347 		return ERR_PTR(ret);
348 	}
349 
350 	return dwmac;
351 }
352 
353 const struct stmmac_of_data stih4xx_dwmac_data = {
354 	.fix_mac_speed = stih4xx_fix_retime_src,
355 	.setup = sti_dwmac_setup,
356 	.init = stix4xx_init,
357 	.exit = sti_dwmac_exit,
358 };
359 
360 const struct stmmac_of_data stid127_dwmac_data = {
361 	.fix_mac_speed = stid127_fix_retime_src,
362 	.setup = sti_dwmac_setup,
363 	.init = stid127_init,
364 	.exit = sti_dwmac_exit,
365 };
366