1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * UFS PHY driver for Samsung SoC
4  *
5  * Copyright (C) 2020 Samsung Electronics Co., Ltd.
6  * Author: Seungwon Jeon <essuuj@gmail.com>
7  * Author: Alim Akhtar <alim.akhtar@samsung.com>
8  *
9  */
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/err.h>
13 #include <linux/of.h>
14 #include <linux/io.h>
15 #include <linux/iopoll.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/module.h>
18 #include <linux/phy/phy.h>
19 #include <linux/platform_device.h>
20 #include <linux/regmap.h>
21 
22 #include "phy-samsung-ufs.h"
23 
24 #define for_each_phy_lane(phy, i) \
25 	for (i = 0; i < (phy)->lane_cnt; i++)
26 #define for_each_phy_cfg(cfg) \
27 	for (; (cfg)->id; (cfg)++)
28 
29 #define PHY_DEF_LANE_CNT	1
30 
31 static void samsung_ufs_phy_config(struct samsung_ufs_phy *phy,
32 				   const struct samsung_ufs_phy_cfg *cfg,
33 				   u8 lane)
34 {
35 	enum {LANE_0, LANE_1}; /* lane index */
36 
37 	switch (lane) {
38 	case LANE_0:
39 		writel(cfg->val, (phy)->reg_pma + cfg->off_0);
40 		break;
41 	case LANE_1:
42 		if (cfg->id == PHY_TRSV_BLK)
43 			writel(cfg->val, (phy)->reg_pma + cfg->off_1);
44 		break;
45 	}
46 }
47 
48 static int samsung_ufs_phy_wait_for_lock_acq(struct phy *phy)
49 {
50 	struct samsung_ufs_phy *ufs_phy = get_samsung_ufs_phy(phy);
51 	const unsigned int timeout_us = 100000;
52 	const unsigned int sleep_us = 10;
53 	u32 val;
54 	int err;
55 
56 	err = readl_poll_timeout(
57 			ufs_phy->reg_pma + PHY_APB_ADDR(PHY_PLL_LOCK_STATUS),
58 			val, (val & PHY_PLL_LOCK_BIT), sleep_us, timeout_us);
59 	if (err) {
60 		dev_err(ufs_phy->dev,
61 			"failed to get phy pll lock acquisition %d\n", err);
62 		goto out;
63 	}
64 
65 	err = readl_poll_timeout(
66 			ufs_phy->reg_pma + PHY_APB_ADDR(PHY_CDR_LOCK_STATUS),
67 			val, (val & PHY_CDR_LOCK_BIT), sleep_us, timeout_us);
68 	if (err)
69 		dev_err(ufs_phy->dev,
70 			"failed to get phy cdr lock acquisition %d\n", err);
71 out:
72 	return err;
73 }
74 
75 static int samsung_ufs_phy_calibrate(struct phy *phy)
76 {
77 	struct samsung_ufs_phy *ufs_phy = get_samsung_ufs_phy(phy);
78 	struct samsung_ufs_phy_cfg **cfgs = ufs_phy->cfg;
79 	const struct samsung_ufs_phy_cfg *cfg;
80 	int err = 0;
81 	int i;
82 
83 	if (unlikely(ufs_phy->ufs_phy_state < CFG_PRE_INIT ||
84 		     ufs_phy->ufs_phy_state >= CFG_TAG_MAX)) {
85 		dev_err(ufs_phy->dev, "invalid phy config index %d\n", ufs_phy->ufs_phy_state);
86 		return -EINVAL;
87 	}
88 
89 	cfg = cfgs[ufs_phy->ufs_phy_state];
90 	if (!cfg)
91 		goto out;
92 
93 	for_each_phy_cfg(cfg) {
94 		for_each_phy_lane(ufs_phy, i) {
95 			samsung_ufs_phy_config(ufs_phy, cfg, i);
96 		}
97 	}
98 
99 	if (ufs_phy->ufs_phy_state == CFG_POST_PWR_HS)
100 		err = samsung_ufs_phy_wait_for_lock_acq(phy);
101 
102 	/**
103 	 * In Samsung ufshci, PHY need to be calibrated at different
104 	 * stages / state mainly before Linkstartup, after Linkstartup,
105 	 * before power mode change and after power mode change.
106 	 * Below state machine to make sure to calibrate PHY in each
107 	 * state. Here after configuring PHY in a given state, will
108 	 * change the state to next state so that next state phy
109 	 * calibration value can be programed
110 	 */
111 out:
112 	switch (ufs_phy->ufs_phy_state) {
113 	case CFG_PRE_INIT:
114 		ufs_phy->ufs_phy_state = CFG_POST_INIT;
115 		break;
116 	case CFG_POST_INIT:
117 		ufs_phy->ufs_phy_state = CFG_PRE_PWR_HS;
118 		break;
119 	case CFG_PRE_PWR_HS:
120 		ufs_phy->ufs_phy_state = CFG_POST_PWR_HS;
121 		break;
122 	case CFG_POST_PWR_HS:
123 		/* Change back to INIT state */
124 		ufs_phy->ufs_phy_state = CFG_PRE_INIT;
125 		break;
126 	default:
127 		dev_err(ufs_phy->dev, "wrong state for phy calibration\n");
128 	}
129 
130 	return err;
131 }
132 
133 static int samsung_ufs_phy_symbol_clk_init(struct samsung_ufs_phy *phy)
134 {
135 	int ret;
136 
137 	phy->tx0_symbol_clk = devm_clk_get(phy->dev, "tx0_symbol_clk");
138 	if (IS_ERR(phy->tx0_symbol_clk)) {
139 		dev_err(phy->dev, "failed to get tx0_symbol_clk clock\n");
140 		return PTR_ERR(phy->tx0_symbol_clk);
141 	}
142 
143 	phy->rx0_symbol_clk = devm_clk_get(phy->dev, "rx0_symbol_clk");
144 	if (IS_ERR(phy->rx0_symbol_clk)) {
145 		dev_err(phy->dev, "failed to get rx0_symbol_clk clock\n");
146 		return PTR_ERR(phy->rx0_symbol_clk);
147 	}
148 
149 	phy->rx1_symbol_clk = devm_clk_get(phy->dev, "rx1_symbol_clk");
150 	if (IS_ERR(phy->rx1_symbol_clk)) {
151 		dev_err(phy->dev, "failed to get rx1_symbol_clk clock\n");
152 		return PTR_ERR(phy->rx1_symbol_clk);
153 	}
154 
155 	ret = clk_prepare_enable(phy->tx0_symbol_clk);
156 	if (ret) {
157 		dev_err(phy->dev, "%s: tx0_symbol_clk enable failed %d\n", __func__, ret);
158 		goto out;
159 	}
160 
161 	ret = clk_prepare_enable(phy->rx0_symbol_clk);
162 	if (ret) {
163 		dev_err(phy->dev, "%s: rx0_symbol_clk enable failed %d\n", __func__, ret);
164 		goto out_disable_tx0_clk;
165 	}
166 
167 	ret = clk_prepare_enable(phy->rx1_symbol_clk);
168 	if (ret) {
169 		dev_err(phy->dev, "%s: rx1_symbol_clk enable failed %d\n", __func__, ret);
170 		goto out_disable_rx0_clk;
171 	}
172 
173 	return 0;
174 
175 out_disable_rx0_clk:
176 	clk_disable_unprepare(phy->rx0_symbol_clk);
177 out_disable_tx0_clk:
178 	clk_disable_unprepare(phy->tx0_symbol_clk);
179 out:
180 	return ret;
181 }
182 
183 static int samsung_ufs_phy_clks_init(struct samsung_ufs_phy *phy)
184 {
185 	int ret;
186 
187 	phy->ref_clk = devm_clk_get(phy->dev, "ref_clk");
188 	if (IS_ERR(phy->ref_clk))
189 		dev_err(phy->dev, "failed to get ref_clk clock\n");
190 
191 	ret = clk_prepare_enable(phy->ref_clk);
192 	if (ret) {
193 		dev_err(phy->dev, "%s: ref_clk enable failed %d\n", __func__, ret);
194 		return ret;
195 	}
196 
197 	dev_dbg(phy->dev, "UFS MPHY ref_clk_rate = %ld\n", clk_get_rate(phy->ref_clk));
198 
199 	return 0;
200 }
201 
202 static int samsung_ufs_phy_init(struct phy *phy)
203 {
204 	struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);
205 	int ret;
206 
207 	ss_phy->lane_cnt = phy->attrs.bus_width;
208 	ss_phy->ufs_phy_state = CFG_PRE_INIT;
209 
210 	if (ss_phy->drvdata->has_symbol_clk) {
211 		ret = samsung_ufs_phy_symbol_clk_init(ss_phy);
212 		if (ret)
213 			dev_err(ss_phy->dev, "failed to set ufs phy symbol clocks\n");
214 	}
215 
216 	ret = samsung_ufs_phy_clks_init(ss_phy);
217 	if (ret)
218 		dev_err(ss_phy->dev, "failed to set ufs phy clocks\n");
219 
220 	ret = samsung_ufs_phy_calibrate(phy);
221 	if (ret)
222 		dev_err(ss_phy->dev, "ufs phy calibration failed\n");
223 
224 	return ret;
225 }
226 
227 static int samsung_ufs_phy_power_on(struct phy *phy)
228 {
229 	struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);
230 
231 	samsung_ufs_phy_ctrl_isol(ss_phy, false);
232 	return 0;
233 }
234 
235 static int samsung_ufs_phy_power_off(struct phy *phy)
236 {
237 	struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);
238 
239 	samsung_ufs_phy_ctrl_isol(ss_phy, true);
240 	return 0;
241 }
242 
243 static int samsung_ufs_phy_set_mode(struct phy *generic_phy,
244 				    enum phy_mode mode, int submode)
245 {
246 	struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(generic_phy);
247 
248 	ss_phy->mode = PHY_MODE_INVALID;
249 
250 	if (mode > 0)
251 		ss_phy->mode = mode;
252 
253 	return 0;
254 }
255 
256 static int samsung_ufs_phy_exit(struct phy *phy)
257 {
258 	struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);
259 
260 	clk_disable_unprepare(ss_phy->ref_clk);
261 
262 	if (ss_phy->drvdata->has_symbol_clk) {
263 		clk_disable_unprepare(ss_phy->tx0_symbol_clk);
264 		clk_disable_unprepare(ss_phy->rx0_symbol_clk);
265 		clk_disable_unprepare(ss_phy->rx1_symbol_clk);
266 	}
267 
268 	return 0;
269 }
270 
271 static const struct phy_ops samsung_ufs_phy_ops = {
272 	.init		= samsung_ufs_phy_init,
273 	.exit		= samsung_ufs_phy_exit,
274 	.power_on	= samsung_ufs_phy_power_on,
275 	.power_off	= samsung_ufs_phy_power_off,
276 	.calibrate	= samsung_ufs_phy_calibrate,
277 	.set_mode	= samsung_ufs_phy_set_mode,
278 	.owner          = THIS_MODULE,
279 };
280 
281 static const struct of_device_id samsung_ufs_phy_match[];
282 
283 static int samsung_ufs_phy_probe(struct platform_device *pdev)
284 {
285 	struct device *dev = &pdev->dev;
286 	const struct of_device_id *match;
287 	struct samsung_ufs_phy *phy;
288 	struct phy *gen_phy;
289 	struct phy_provider *phy_provider;
290 	const struct samsung_ufs_phy_drvdata *drvdata;
291 	int err = 0;
292 
293 	match = of_match_node(samsung_ufs_phy_match, dev->of_node);
294 	if (!match) {
295 		err = -EINVAL;
296 		dev_err(dev, "failed to get match_node\n");
297 		goto out;
298 	}
299 
300 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
301 	if (!phy) {
302 		err = -ENOMEM;
303 		goto out;
304 	}
305 
306 	phy->reg_pma = devm_platform_ioremap_resource_byname(pdev, "phy-pma");
307 	if (IS_ERR(phy->reg_pma)) {
308 		err = PTR_ERR(phy->reg_pma);
309 		goto out;
310 	}
311 
312 	phy->reg_pmu = syscon_regmap_lookup_by_phandle(
313 				dev->of_node, "samsung,pmu-syscon");
314 	if (IS_ERR(phy->reg_pmu)) {
315 		err = PTR_ERR(phy->reg_pmu);
316 		dev_err(dev, "failed syscon remap for pmu\n");
317 		goto out;
318 	}
319 
320 	gen_phy = devm_phy_create(dev, NULL, &samsung_ufs_phy_ops);
321 	if (IS_ERR(gen_phy)) {
322 		err = PTR_ERR(gen_phy);
323 		dev_err(dev, "failed to create PHY for ufs-phy\n");
324 		goto out;
325 	}
326 
327 	drvdata = match->data;
328 	phy->dev = dev;
329 	phy->drvdata = drvdata;
330 	phy->cfg = (struct samsung_ufs_phy_cfg **)drvdata->cfg;
331 	phy->isol = &drvdata->isol;
332 	phy->lane_cnt = PHY_DEF_LANE_CNT;
333 
334 	phy_set_drvdata(gen_phy, phy);
335 
336 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
337 	if (IS_ERR(phy_provider)) {
338 		err = PTR_ERR(phy_provider);
339 		dev_err(dev, "failed to register phy-provider\n");
340 		goto out;
341 	}
342 out:
343 	return err;
344 }
345 
346 static const struct of_device_id samsung_ufs_phy_match[] = {
347 	{
348 		.compatible = "samsung,exynos7-ufs-phy",
349 		.data = &exynos7_ufs_phy,
350 	}, {
351 		.compatible = "samsung,exynosautov9-ufs-phy",
352 		.data = &exynosautov9_ufs_phy,
353 	},
354 	{},
355 };
356 MODULE_DEVICE_TABLE(of, samsung_ufs_phy_match);
357 
358 static struct platform_driver samsung_ufs_phy_driver = {
359 	.probe  = samsung_ufs_phy_probe,
360 	.driver = {
361 		.name = "samsung-ufs-phy",
362 		.of_match_table = samsung_ufs_phy_match,
363 	},
364 };
365 module_platform_driver(samsung_ufs_phy_driver);
366 MODULE_DESCRIPTION("Samsung SoC UFS PHY Driver");
367 MODULE_AUTHOR("Seungwon Jeon <essuuj@gmail.com>");
368 MODULE_AUTHOR("Alim Akhtar <alim.akhtar@samsung.com>");
369 MODULE_LICENSE("GPL v2");
370