1 /*
2  * Qualcomm Atheros IPQ806x GMAC glue layer
3  *
4  * Copyright (C) 2015 The Linux Foundation
5  *
6  * Permission to use, copy, modify, and/or distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <linux/device.h>
20 #include <linux/platform_device.h>
21 #include <linux/phy.h>
22 #include <linux/regmap.h>
23 #include <linux/clk.h>
24 #include <linux/reset.h>
25 #include <linux/of_net.h>
26 #include <linux/mfd/syscon.h>
27 #include <linux/stmmac.h>
28 #include <linux/of_mdio.h>
29 #include <linux/module.h>
30 
31 #include "stmmac_platform.h"
32 
33 #define NSS_COMMON_CLK_GATE			0x8
34 #define NSS_COMMON_CLK_GATE_PTP_EN(x)		BIT(0x10 + x)
35 #define NSS_COMMON_CLK_GATE_RGMII_RX_EN(x)	BIT(0x9 + (x * 2))
36 #define NSS_COMMON_CLK_GATE_RGMII_TX_EN(x)	BIT(0x8 + (x * 2))
37 #define NSS_COMMON_CLK_GATE_GMII_RX_EN(x)	BIT(0x4 + x)
38 #define NSS_COMMON_CLK_GATE_GMII_TX_EN(x)	BIT(0x0 + x)
39 
40 #define NSS_COMMON_CLK_DIV0			0xC
41 #define NSS_COMMON_CLK_DIV_OFFSET(x)		(x * 8)
42 #define NSS_COMMON_CLK_DIV_MASK			0x7f
43 
44 #define NSS_COMMON_CLK_SRC_CTRL			0x14
45 #define NSS_COMMON_CLK_SRC_CTRL_OFFSET(x)	(x)
46 /* Mode is coded on 1 bit but is different depending on the MAC ID:
47  * MAC0: QSGMII=0 RGMII=1
48  * MAC1: QSGMII=0 SGMII=0 RGMII=1
49  * MAC2 & MAC3: QSGMII=0 SGMII=1
50  */
51 #define NSS_COMMON_CLK_SRC_CTRL_RGMII(x)	1
52 #define NSS_COMMON_CLK_SRC_CTRL_SGMII(x)	((x >= 2) ? 1 : 0)
53 
54 #define NSS_COMMON_GMAC_CTL(x)			(0x30 + (x * 4))
55 #define NSS_COMMON_GMAC_CTL_CSYS_REQ		BIT(19)
56 #define NSS_COMMON_GMAC_CTL_PHY_IFACE_SEL	BIT(16)
57 #define NSS_COMMON_GMAC_CTL_IFG_LIMIT_OFFSET	8
58 #define NSS_COMMON_GMAC_CTL_IFG_OFFSET		0
59 
60 #define NSS_COMMON_CLK_DIV_RGMII_1000		1
61 #define NSS_COMMON_CLK_DIV_RGMII_100		9
62 #define NSS_COMMON_CLK_DIV_RGMII_10		99
63 #define NSS_COMMON_CLK_DIV_SGMII_1000		0
64 #define NSS_COMMON_CLK_DIV_SGMII_100		4
65 #define NSS_COMMON_CLK_DIV_SGMII_10		49
66 
67 #define QSGMII_PCS_CAL_LCKDT_CTL		0x120
68 #define QSGMII_PCS_CAL_LCKDT_CTL_RST		BIT(19)
69 
70 /* Only GMAC1/2/3 support SGMII and their CTL register are not contiguous */
71 #define QSGMII_PHY_SGMII_CTL(x)			((x == 1) ? 0x134 : \
72 						 (0x13c + (4 * (x - 2))))
73 #define QSGMII_PHY_CDR_EN			BIT(0)
74 #define QSGMII_PHY_RX_FRONT_EN			BIT(1)
75 #define QSGMII_PHY_RX_SIGNAL_DETECT_EN		BIT(2)
76 #define QSGMII_PHY_TX_DRIVER_EN			BIT(3)
77 #define QSGMII_PHY_QSGMII_EN			BIT(7)
78 #define QSGMII_PHY_PHASE_LOOP_GAIN_OFFSET	12
79 #define QSGMII_PHY_RX_DC_BIAS_OFFSET		18
80 #define QSGMII_PHY_RX_INPUT_EQU_OFFSET		20
81 #define QSGMII_PHY_CDR_PI_SLEW_OFFSET		22
82 #define QSGMII_PHY_TX_DRV_AMP_OFFSET		28
83 
84 struct ipq806x_gmac {
85 	struct platform_device *pdev;
86 	struct regmap *nss_common;
87 	struct regmap *qsgmii_csr;
88 	uint32_t id;
89 	struct clk *core_clk;
90 	phy_interface_t phy_mode;
91 };
92 
93 static int get_clk_div_sgmii(struct ipq806x_gmac *gmac, unsigned int speed)
94 {
95 	struct device *dev = &gmac->pdev->dev;
96 	int div;
97 
98 	switch (speed) {
99 	case SPEED_1000:
100 		div = NSS_COMMON_CLK_DIV_SGMII_1000;
101 		break;
102 
103 	case SPEED_100:
104 		div = NSS_COMMON_CLK_DIV_SGMII_100;
105 		break;
106 
107 	case SPEED_10:
108 		div = NSS_COMMON_CLK_DIV_SGMII_10;
109 		break;
110 
111 	default:
112 		dev_err(dev, "Speed %dMbps not supported in SGMII\n", speed);
113 		return -EINVAL;
114 	}
115 
116 	return div;
117 }
118 
119 static int get_clk_div_rgmii(struct ipq806x_gmac *gmac, unsigned int speed)
120 {
121 	struct device *dev = &gmac->pdev->dev;
122 	int div;
123 
124 	switch (speed) {
125 	case SPEED_1000:
126 		div = NSS_COMMON_CLK_DIV_RGMII_1000;
127 		break;
128 
129 	case SPEED_100:
130 		div = NSS_COMMON_CLK_DIV_RGMII_100;
131 		break;
132 
133 	case SPEED_10:
134 		div = NSS_COMMON_CLK_DIV_RGMII_10;
135 		break;
136 
137 	default:
138 		dev_err(dev, "Speed %dMbps not supported in RGMII\n", speed);
139 		return -EINVAL;
140 	}
141 
142 	return div;
143 }
144 
145 static int ipq806x_gmac_set_speed(struct ipq806x_gmac *gmac, unsigned int speed)
146 {
147 	uint32_t clk_bits, val;
148 	int div;
149 
150 	switch (gmac->phy_mode) {
151 	case PHY_INTERFACE_MODE_RGMII:
152 		div = get_clk_div_rgmii(gmac, speed);
153 		clk_bits = NSS_COMMON_CLK_GATE_RGMII_RX_EN(gmac->id) |
154 			   NSS_COMMON_CLK_GATE_RGMII_TX_EN(gmac->id);
155 		break;
156 
157 	case PHY_INTERFACE_MODE_SGMII:
158 		div = get_clk_div_sgmii(gmac, speed);
159 		clk_bits = NSS_COMMON_CLK_GATE_GMII_RX_EN(gmac->id) |
160 			   NSS_COMMON_CLK_GATE_GMII_TX_EN(gmac->id);
161 		break;
162 
163 	default:
164 		dev_err(&gmac->pdev->dev, "Unsupported PHY mode: \"%s\"\n",
165 			phy_modes(gmac->phy_mode));
166 		return -EINVAL;
167 	}
168 
169 	/* Disable the clocks */
170 	regmap_read(gmac->nss_common, NSS_COMMON_CLK_GATE, &val);
171 	val &= ~clk_bits;
172 	regmap_write(gmac->nss_common, NSS_COMMON_CLK_GATE, val);
173 
174 	/* Set the divider */
175 	regmap_read(gmac->nss_common, NSS_COMMON_CLK_DIV0, &val);
176 	val &= ~(NSS_COMMON_CLK_DIV_MASK
177 		 << NSS_COMMON_CLK_DIV_OFFSET(gmac->id));
178 	val |= div << NSS_COMMON_CLK_DIV_OFFSET(gmac->id);
179 	regmap_write(gmac->nss_common, NSS_COMMON_CLK_DIV0, val);
180 
181 	/* Enable the clock back */
182 	regmap_read(gmac->nss_common, NSS_COMMON_CLK_GATE, &val);
183 	val |= clk_bits;
184 	regmap_write(gmac->nss_common, NSS_COMMON_CLK_GATE, val);
185 
186 	return 0;
187 }
188 
189 static int ipq806x_gmac_of_parse(struct ipq806x_gmac *gmac)
190 {
191 	struct device *dev = &gmac->pdev->dev;
192 
193 	gmac->phy_mode = of_get_phy_mode(dev->of_node);
194 	if (gmac->phy_mode < 0) {
195 		dev_err(dev, "missing phy mode property\n");
196 		return -EINVAL;
197 	}
198 
199 	if (of_property_read_u32(dev->of_node, "qcom,id", &gmac->id) < 0) {
200 		dev_err(dev, "missing qcom id property\n");
201 		return -EINVAL;
202 	}
203 
204 	/* The GMACs are called 1 to 4 in the documentation, but to simplify the
205 	 * code and keep it consistent with the Linux convention, we'll number
206 	 * them from 0 to 3 here.
207 	 */
208 	if (gmac->id > 3) {
209 		dev_err(dev, "invalid gmac id\n");
210 		return -EINVAL;
211 	}
212 
213 	gmac->core_clk = devm_clk_get(dev, "stmmaceth");
214 	if (IS_ERR(gmac->core_clk)) {
215 		dev_err(dev, "missing stmmaceth clk property\n");
216 		return PTR_ERR(gmac->core_clk);
217 	}
218 	clk_set_rate(gmac->core_clk, 266000000);
219 
220 	/* Setup the register map for the nss common registers */
221 	gmac->nss_common = syscon_regmap_lookup_by_phandle(dev->of_node,
222 							   "qcom,nss-common");
223 	if (IS_ERR(gmac->nss_common)) {
224 		dev_err(dev, "missing nss-common node\n");
225 		return PTR_ERR(gmac->nss_common);
226 	}
227 
228 	/* Setup the register map for the qsgmii csr registers */
229 	gmac->qsgmii_csr = syscon_regmap_lookup_by_phandle(dev->of_node,
230 							   "qcom,qsgmii-csr");
231 	if (IS_ERR(gmac->qsgmii_csr))
232 		dev_err(dev, "missing qsgmii-csr node\n");
233 
234 	return PTR_ERR_OR_ZERO(gmac->qsgmii_csr);
235 }
236 
237 static void ipq806x_gmac_fix_mac_speed(void *priv, unsigned int speed)
238 {
239 	struct ipq806x_gmac *gmac = priv;
240 
241 	ipq806x_gmac_set_speed(gmac, speed);
242 }
243 
244 static int ipq806x_gmac_probe(struct platform_device *pdev)
245 {
246 	struct plat_stmmacenet_data *plat_dat;
247 	struct stmmac_resources stmmac_res;
248 	struct device *dev = &pdev->dev;
249 	struct ipq806x_gmac *gmac;
250 	int val;
251 	int err;
252 
253 	val = stmmac_get_platform_resources(pdev, &stmmac_res);
254 	if (val)
255 		return val;
256 
257 	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
258 	if (IS_ERR(plat_dat))
259 		return PTR_ERR(plat_dat);
260 
261 	gmac = devm_kzalloc(dev, sizeof(*gmac), GFP_KERNEL);
262 	if (!gmac) {
263 		err = -ENOMEM;
264 		goto err_remove_config_dt;
265 	}
266 
267 	gmac->pdev = pdev;
268 
269 	err = ipq806x_gmac_of_parse(gmac);
270 	if (err) {
271 		dev_err(dev, "device tree parsing error\n");
272 		goto err_remove_config_dt;
273 	}
274 
275 	regmap_write(gmac->qsgmii_csr, QSGMII_PCS_CAL_LCKDT_CTL,
276 		     QSGMII_PCS_CAL_LCKDT_CTL_RST);
277 
278 	/* Inter frame gap is set to 12 */
279 	val = 12 << NSS_COMMON_GMAC_CTL_IFG_OFFSET |
280 	      12 << NSS_COMMON_GMAC_CTL_IFG_LIMIT_OFFSET;
281 	/* We also initiate an AXI low power exit request */
282 	val |= NSS_COMMON_GMAC_CTL_CSYS_REQ;
283 	switch (gmac->phy_mode) {
284 	case PHY_INTERFACE_MODE_RGMII:
285 		val |= NSS_COMMON_GMAC_CTL_PHY_IFACE_SEL;
286 		break;
287 	case PHY_INTERFACE_MODE_SGMII:
288 		val &= ~NSS_COMMON_GMAC_CTL_PHY_IFACE_SEL;
289 		break;
290 	default:
291 		dev_err(&pdev->dev, "Unsupported PHY mode: \"%s\"\n",
292 			phy_modes(gmac->phy_mode));
293 		err = -EINVAL;
294 		goto err_remove_config_dt;
295 	}
296 	regmap_write(gmac->nss_common, NSS_COMMON_GMAC_CTL(gmac->id), val);
297 
298 	/* Configure the clock src according to the mode */
299 	regmap_read(gmac->nss_common, NSS_COMMON_CLK_SRC_CTRL, &val);
300 	val &= ~(1 << NSS_COMMON_CLK_SRC_CTRL_OFFSET(gmac->id));
301 	switch (gmac->phy_mode) {
302 	case PHY_INTERFACE_MODE_RGMII:
303 		val |= NSS_COMMON_CLK_SRC_CTRL_RGMII(gmac->id) <<
304 			NSS_COMMON_CLK_SRC_CTRL_OFFSET(gmac->id);
305 		break;
306 	case PHY_INTERFACE_MODE_SGMII:
307 		val |= NSS_COMMON_CLK_SRC_CTRL_SGMII(gmac->id) <<
308 			NSS_COMMON_CLK_SRC_CTRL_OFFSET(gmac->id);
309 		break;
310 	default:
311 		dev_err(&pdev->dev, "Unsupported PHY mode: \"%s\"\n",
312 			phy_modes(gmac->phy_mode));
313 		err = -EINVAL;
314 		goto err_remove_config_dt;
315 	}
316 	regmap_write(gmac->nss_common, NSS_COMMON_CLK_SRC_CTRL, val);
317 
318 	/* Enable PTP clock */
319 	regmap_read(gmac->nss_common, NSS_COMMON_CLK_GATE, &val);
320 	val |= NSS_COMMON_CLK_GATE_PTP_EN(gmac->id);
321 	regmap_write(gmac->nss_common, NSS_COMMON_CLK_GATE, val);
322 
323 	if (gmac->phy_mode == PHY_INTERFACE_MODE_SGMII) {
324 		regmap_write(gmac->qsgmii_csr, QSGMII_PHY_SGMII_CTL(gmac->id),
325 			     QSGMII_PHY_CDR_EN |
326 			     QSGMII_PHY_RX_FRONT_EN |
327 			     QSGMII_PHY_RX_SIGNAL_DETECT_EN |
328 			     QSGMII_PHY_TX_DRIVER_EN |
329 			     QSGMII_PHY_QSGMII_EN |
330 			     0x4ul << QSGMII_PHY_PHASE_LOOP_GAIN_OFFSET |
331 			     0x3ul << QSGMII_PHY_RX_DC_BIAS_OFFSET |
332 			     0x1ul << QSGMII_PHY_RX_INPUT_EQU_OFFSET |
333 			     0x2ul << QSGMII_PHY_CDR_PI_SLEW_OFFSET |
334 			     0xCul << QSGMII_PHY_TX_DRV_AMP_OFFSET);
335 	}
336 
337 	plat_dat->has_gmac = true;
338 	plat_dat->bsp_priv = gmac;
339 	plat_dat->fix_mac_speed = ipq806x_gmac_fix_mac_speed;
340 
341 	err = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
342 	if (err)
343 		goto err_remove_config_dt;
344 
345 	return 0;
346 
347 err_remove_config_dt:
348 	stmmac_remove_config_dt(pdev, plat_dat);
349 
350 	return err;
351 }
352 
353 static const struct of_device_id ipq806x_gmac_dwmac_match[] = {
354 	{ .compatible = "qcom,ipq806x-gmac" },
355 	{ }
356 };
357 MODULE_DEVICE_TABLE(of, ipq806x_gmac_dwmac_match);
358 
359 static struct platform_driver ipq806x_gmac_dwmac_driver = {
360 	.probe = ipq806x_gmac_probe,
361 	.remove = stmmac_pltfr_remove,
362 	.driver = {
363 		.name		= "ipq806x-gmac-dwmac",
364 		.pm		= &stmmac_pltfr_pm_ops,
365 		.of_match_table	= ipq806x_gmac_dwmac_match,
366 	},
367 };
368 module_platform_driver(ipq806x_gmac_dwmac_driver);
369 
370 MODULE_AUTHOR("Mathieu Olivari <mathieu@codeaurora.org>");
371 MODULE_DESCRIPTION("Qualcomm Atheros IPQ806x DWMAC specific glue layer");
372 MODULE_LICENSE("Dual BSD/GPL");
373