xref: /linux/drivers/phy/cadence/cdns-dphy.c (revision f85f5ae45ad945270a8884261de8249431e8b5a6)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright: 2017-2018 Cadence Design Systems, Inc.
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/bitops.h>
8 #include <linux/clk.h>
9 #include <linux/io.h>
10 #include <linux/iopoll.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/reset.h>
15 
16 #include <linux/phy/phy.h>
17 #include <linux/phy/phy-mipi-dphy.h>
18 
19 #define REG_WAKEUP_TIME_NS		800
20 #define DPHY_PLL_RATE_HZ		108000000
21 #define POLL_TIMEOUT_US			1000
22 
23 /* DPHY registers */
24 #define DPHY_PMA_CMN(reg)		(reg)
25 #define DPHY_PMA_LCLK(reg)		(0x100 + (reg))
26 #define DPHY_PMA_LDATA(lane, reg)	(0x200 + ((lane) * 0x100) + (reg))
27 #define DPHY_PMA_RCLK(reg)		(0x600 + (reg))
28 #define DPHY_PMA_RDATA(lane, reg)	(0x700 + ((lane) * 0x100) + (reg))
29 #define DPHY_PCS(reg)			(0xb00 + (reg))
30 
31 #define DPHY_CMN_SSM			DPHY_PMA_CMN(0x20)
32 #define DPHY_CMN_SSM_EN			BIT(0)
33 #define DPHY_CMN_TX_MODE_EN		BIT(9)
34 
35 #define DPHY_CMN_PWM			DPHY_PMA_CMN(0x40)
36 #define DPHY_CMN_PWM_DIV(x)		((x) << 20)
37 #define DPHY_CMN_PWM_LOW(x)		((x) << 10)
38 #define DPHY_CMN_PWM_HIGH(x)		(x)
39 
40 #define DPHY_CMN_FBDIV			DPHY_PMA_CMN(0x4c)
41 #define DPHY_CMN_FBDIV_VAL(low, high)	(((high) << 11) | ((low) << 22))
42 #define DPHY_CMN_FBDIV_FROM_REG		(BIT(10) | BIT(21))
43 
44 #define DPHY_CMN_OPIPDIV		DPHY_PMA_CMN(0x50)
45 #define DPHY_CMN_IPDIV_FROM_REG		BIT(0)
46 #define DPHY_CMN_IPDIV(x)		((x) << 1)
47 #define DPHY_CMN_OPDIV_FROM_REG		BIT(6)
48 #define DPHY_CMN_OPDIV(x)		((x) << 7)
49 
50 #define DPHY_BAND_CFG			DPHY_PCS(0x0)
51 #define DPHY_BAND_CFG_LEFT_BAND		GENMASK(4, 0)
52 #define DPHY_BAND_CFG_RIGHT_BAND	GENMASK(9, 5)
53 
54 #define DPHY_PSM_CFG			DPHY_PCS(0x4)
55 #define DPHY_PSM_CFG_FROM_REG		BIT(0)
56 #define DPHY_PSM_CLK_DIV(x)		((x) << 1)
57 
58 #define DSI_HBP_FRAME_OVERHEAD		12
59 #define DSI_HSA_FRAME_OVERHEAD		14
60 #define DSI_HFP_FRAME_OVERHEAD		6
61 #define DSI_HSS_VSS_VSE_FRAME_OVERHEAD	4
62 #define DSI_BLANKING_FRAME_OVERHEAD	6
63 #define DSI_NULL_FRAME_OVERHEAD		6
64 #define DSI_EOT_PKT_SIZE		4
65 
66 #define DPHY_TX_J721E_WIZ_PLL_CTRL	0xF04
67 #define DPHY_TX_J721E_WIZ_STATUS	0xF08
68 #define DPHY_TX_J721E_WIZ_RST_CTRL	0xF0C
69 #define DPHY_TX_J721E_WIZ_PSM_FREQ	0xF10
70 
71 #define DPHY_TX_J721E_WIZ_IPDIV		GENMASK(4, 0)
72 #define DPHY_TX_J721E_WIZ_OPDIV		GENMASK(13, 8)
73 #define DPHY_TX_J721E_WIZ_FBDIV		GENMASK(25, 16)
74 #define DPHY_TX_J721E_WIZ_LANE_RSTB	BIT(31)
75 #define DPHY_TX_WIZ_PLL_LOCK		BIT(31)
76 #define DPHY_TX_WIZ_O_CMN_READY		BIT(31)
77 
78 struct cdns_dphy_cfg {
79 	u8 pll_ipdiv;
80 	u8 pll_opdiv;
81 	u16 pll_fbdiv;
82 	unsigned int nlanes;
83 };
84 
85 enum cdns_dphy_clk_lane_cfg {
86 	DPHY_CLK_CFG_LEFT_DRIVES_ALL = 0,
87 	DPHY_CLK_CFG_LEFT_DRIVES_RIGHT = 1,
88 	DPHY_CLK_CFG_LEFT_DRIVES_LEFT = 2,
89 	DPHY_CLK_CFG_RIGHT_DRIVES_ALL = 3,
90 };
91 
92 struct cdns_dphy;
93 struct cdns_dphy_ops {
94 	int (*probe)(struct cdns_dphy *dphy);
95 	void (*remove)(struct cdns_dphy *dphy);
96 	void (*set_psm_div)(struct cdns_dphy *dphy, u8 div);
97 	void (*set_clk_lane_cfg)(struct cdns_dphy *dphy,
98 				 enum cdns_dphy_clk_lane_cfg cfg);
99 	void (*set_pll_cfg)(struct cdns_dphy *dphy,
100 			    const struct cdns_dphy_cfg *cfg);
101 	unsigned long (*get_wakeup_time_ns)(struct cdns_dphy *dphy);
102 };
103 
104 struct cdns_dphy {
105 	struct cdns_dphy_cfg cfg;
106 	void __iomem *regs;
107 	struct clk *psm_clk;
108 	struct clk *pll_ref_clk;
109 	const struct cdns_dphy_ops *ops;
110 	struct phy *phy;
111 };
112 
113 /* Order of bands is important since the index is the band number. */
114 static const unsigned int tx_bands[] = {
115 	80, 100, 120, 160, 200, 240, 320, 390, 450, 510, 560, 640, 690, 770,
116 	870, 950, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2500
117 };
118 
119 static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
120 				     struct cdns_dphy_cfg *cfg,
121 				     struct phy_configure_opts_mipi_dphy *opts,
122 				     unsigned int *dsi_hfp_ext)
123 {
124 	unsigned long pll_ref_hz = clk_get_rate(dphy->pll_ref_clk);
125 	u64 dlane_bps;
126 
127 	memset(cfg, 0, sizeof(*cfg));
128 
129 	if (pll_ref_hz < 9600000 || pll_ref_hz >= 150000000)
130 		return -EINVAL;
131 	else if (pll_ref_hz < 19200000)
132 		cfg->pll_ipdiv = 1;
133 	else if (pll_ref_hz < 38400000)
134 		cfg->pll_ipdiv = 2;
135 	else if (pll_ref_hz < 76800000)
136 		cfg->pll_ipdiv = 4;
137 	else
138 		cfg->pll_ipdiv = 8;
139 
140 	dlane_bps = opts->hs_clk_rate;
141 
142 	if (dlane_bps > 2500000000UL || dlane_bps < 160000000UL)
143 		return -EINVAL;
144 	else if (dlane_bps >= 1250000000)
145 		cfg->pll_opdiv = 1;
146 	else if (dlane_bps >= 630000000)
147 		cfg->pll_opdiv = 2;
148 	else if (dlane_bps >= 320000000)
149 		cfg->pll_opdiv = 4;
150 	else if (dlane_bps >= 160000000)
151 		cfg->pll_opdiv = 8;
152 
153 	cfg->pll_fbdiv = DIV_ROUND_UP_ULL(dlane_bps * 2 * cfg->pll_opdiv *
154 					  cfg->pll_ipdiv,
155 					  pll_ref_hz);
156 
157 	return 0;
158 }
159 
160 static int cdns_dphy_setup_psm(struct cdns_dphy *dphy)
161 {
162 	unsigned long psm_clk_hz = clk_get_rate(dphy->psm_clk);
163 	unsigned long psm_div;
164 
165 	if (!psm_clk_hz || psm_clk_hz > 100000000)
166 		return -EINVAL;
167 
168 	psm_div = DIV_ROUND_CLOSEST(psm_clk_hz, 1000000);
169 	if (dphy->ops->set_psm_div)
170 		dphy->ops->set_psm_div(dphy, psm_div);
171 
172 	return 0;
173 }
174 
175 static void cdns_dphy_set_clk_lane_cfg(struct cdns_dphy *dphy,
176 				       enum cdns_dphy_clk_lane_cfg cfg)
177 {
178 	if (dphy->ops->set_clk_lane_cfg)
179 		dphy->ops->set_clk_lane_cfg(dphy, cfg);
180 }
181 
182 static void cdns_dphy_set_pll_cfg(struct cdns_dphy *dphy,
183 				  const struct cdns_dphy_cfg *cfg)
184 {
185 	if (dphy->ops->set_pll_cfg)
186 		dphy->ops->set_pll_cfg(dphy, cfg);
187 }
188 
189 static unsigned long cdns_dphy_get_wakeup_time_ns(struct cdns_dphy *dphy)
190 {
191 	return dphy->ops->get_wakeup_time_ns(dphy);
192 }
193 
194 static unsigned long cdns_dphy_ref_get_wakeup_time_ns(struct cdns_dphy *dphy)
195 {
196 	/* Default wakeup time is 800 ns (in a simulated environment). */
197 	return 800;
198 }
199 
200 static void cdns_dphy_ref_set_pll_cfg(struct cdns_dphy *dphy,
201 				      const struct cdns_dphy_cfg *cfg)
202 {
203 	u32 fbdiv_low, fbdiv_high;
204 
205 	fbdiv_low = (cfg->pll_fbdiv / 4) - 2;
206 	fbdiv_high = cfg->pll_fbdiv - fbdiv_low - 2;
207 
208 	writel(DPHY_CMN_IPDIV_FROM_REG | DPHY_CMN_OPDIV_FROM_REG |
209 	       DPHY_CMN_IPDIV(cfg->pll_ipdiv) |
210 	       DPHY_CMN_OPDIV(cfg->pll_opdiv),
211 	       dphy->regs + DPHY_CMN_OPIPDIV);
212 	writel(DPHY_CMN_FBDIV_FROM_REG |
213 	       DPHY_CMN_FBDIV_VAL(fbdiv_low, fbdiv_high),
214 	       dphy->regs + DPHY_CMN_FBDIV);
215 	writel(DPHY_CMN_PWM_HIGH(6) | DPHY_CMN_PWM_LOW(0x101) |
216 	       DPHY_CMN_PWM_DIV(0x8),
217 	       dphy->regs + DPHY_CMN_PWM);
218 }
219 
220 static void cdns_dphy_ref_set_psm_div(struct cdns_dphy *dphy, u8 div)
221 {
222 	writel(DPHY_PSM_CFG_FROM_REG | DPHY_PSM_CLK_DIV(div),
223 	       dphy->regs + DPHY_PSM_CFG);
224 }
225 
226 static unsigned long cdns_dphy_j721e_get_wakeup_time_ns(struct cdns_dphy *dphy)
227 {
228 	/* Minimum wakeup time as per MIPI D-PHY spec v1.2 */
229 	return 1000000;
230 }
231 
232 static void cdns_dphy_j721e_set_pll_cfg(struct cdns_dphy *dphy,
233 					const struct cdns_dphy_cfg *cfg)
234 {
235 	u32 status;
236 
237 	/*
238 	 * set the PWM and PLL Byteclk divider settings to recommended values
239 	 * which is same as that of in ref ops
240 	 */
241 	writel(DPHY_CMN_PWM_HIGH(6) | DPHY_CMN_PWM_LOW(0x101) |
242 	       DPHY_CMN_PWM_DIV(0x8),
243 	       dphy->regs + DPHY_CMN_PWM);
244 
245 	writel((FIELD_PREP(DPHY_TX_J721E_WIZ_IPDIV, cfg->pll_ipdiv) |
246 		FIELD_PREP(DPHY_TX_J721E_WIZ_OPDIV, cfg->pll_opdiv) |
247 		FIELD_PREP(DPHY_TX_J721E_WIZ_FBDIV, cfg->pll_fbdiv)),
248 		dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL);
249 
250 	writel(DPHY_TX_J721E_WIZ_LANE_RSTB,
251 	       dphy->regs + DPHY_TX_J721E_WIZ_RST_CTRL);
252 
253 	readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL, status,
254 			   (status & DPHY_TX_WIZ_PLL_LOCK), 0, POLL_TIMEOUT_US);
255 
256 	readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_STATUS, status,
257 			   (status & DPHY_TX_WIZ_O_CMN_READY), 0,
258 			   POLL_TIMEOUT_US);
259 }
260 
261 static void cdns_dphy_j721e_set_psm_div(struct cdns_dphy *dphy, u8 div)
262 {
263 	writel(div, dphy->regs + DPHY_TX_J721E_WIZ_PSM_FREQ);
264 }
265 
266 /*
267  * This is the reference implementation of DPHY hooks. Specific integration of
268  * this IP may have to re-implement some of them depending on how they decided
269  * to wire things in the SoC.
270  */
271 static const struct cdns_dphy_ops ref_dphy_ops = {
272 	.get_wakeup_time_ns = cdns_dphy_ref_get_wakeup_time_ns,
273 	.set_pll_cfg = cdns_dphy_ref_set_pll_cfg,
274 	.set_psm_div = cdns_dphy_ref_set_psm_div,
275 };
276 
277 static const struct cdns_dphy_ops j721e_dphy_ops = {
278 	.get_wakeup_time_ns = cdns_dphy_j721e_get_wakeup_time_ns,
279 	.set_pll_cfg = cdns_dphy_j721e_set_pll_cfg,
280 	.set_psm_div = cdns_dphy_j721e_set_psm_div,
281 };
282 
283 static int cdns_dphy_config_from_opts(struct phy *phy,
284 				      struct phy_configure_opts_mipi_dphy *opts,
285 				      struct cdns_dphy_cfg *cfg)
286 {
287 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
288 	unsigned int dsi_hfp_ext = 0;
289 	int ret;
290 
291 	ret = phy_mipi_dphy_config_validate(opts);
292 	if (ret)
293 		return ret;
294 
295 	ret = cdns_dsi_get_dphy_pll_cfg(dphy, cfg,
296 					opts, &dsi_hfp_ext);
297 	if (ret)
298 		return ret;
299 
300 	opts->wakeup = cdns_dphy_get_wakeup_time_ns(dphy) / 1000;
301 
302 	return 0;
303 }
304 
305 static int cdns_dphy_tx_get_band_ctrl(unsigned long hs_clk_rate)
306 {
307 	unsigned int rate;
308 	int i;
309 
310 	rate = hs_clk_rate / 1000000UL;
311 
312 	if (rate < tx_bands[0])
313 		return -EOPNOTSUPP;
314 
315 	for (i = 0; i < ARRAY_SIZE(tx_bands) - 1; i++) {
316 		if (rate >= tx_bands[i] && rate < tx_bands[i + 1])
317 			return i;
318 	}
319 
320 	return -EOPNOTSUPP;
321 }
322 
323 static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
324 			      union phy_configure_opts *opts)
325 {
326 	struct cdns_dphy_cfg cfg = { 0 };
327 
328 	if (mode != PHY_MODE_MIPI_DPHY)
329 		return -EINVAL;
330 
331 	return cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
332 }
333 
334 static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
335 {
336 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
337 	struct cdns_dphy_cfg cfg = { 0 };
338 	int ret, band_ctrl;
339 	unsigned int reg;
340 
341 	ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
342 	if (ret)
343 		return ret;
344 
345 	/*
346 	 * Configure the internal PSM clk divider so that the DPHY has a
347 	 * 1MHz clk (or something close).
348 	 */
349 	ret = cdns_dphy_setup_psm(dphy);
350 	if (ret)
351 		return ret;
352 
353 	/*
354 	 * Configure attach clk lanes to data lanes: the DPHY has 2 clk lanes
355 	 * and 8 data lanes, each clk lane can be attache different set of
356 	 * data lanes. The 2 groups are named 'left' and 'right', so here we
357 	 * just say that we want the 'left' clk lane to drive the 'left' data
358 	 * lanes.
359 	 */
360 	cdns_dphy_set_clk_lane_cfg(dphy, DPHY_CLK_CFG_LEFT_DRIVES_LEFT);
361 
362 	/*
363 	 * Configure the DPHY PLL that will be used to generate the TX byte
364 	 * clk.
365 	 */
366 	cdns_dphy_set_pll_cfg(dphy, &cfg);
367 
368 	band_ctrl = cdns_dphy_tx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
369 	if (band_ctrl < 0)
370 		return band_ctrl;
371 
372 	reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
373 	      FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
374 	writel(reg, dphy->regs + DPHY_BAND_CFG);
375 
376 	return 0;
377 }
378 
379 static int cdns_dphy_power_on(struct phy *phy)
380 {
381 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
382 
383 	clk_prepare_enable(dphy->psm_clk);
384 	clk_prepare_enable(dphy->pll_ref_clk);
385 
386 	/* Start TX state machine. */
387 	writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN,
388 	       dphy->regs + DPHY_CMN_SSM);
389 
390 	return 0;
391 }
392 
393 static int cdns_dphy_power_off(struct phy *phy)
394 {
395 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
396 
397 	clk_disable_unprepare(dphy->pll_ref_clk);
398 	clk_disable_unprepare(dphy->psm_clk);
399 
400 	return 0;
401 }
402 
403 static const struct phy_ops cdns_dphy_ops = {
404 	.configure	= cdns_dphy_configure,
405 	.validate	= cdns_dphy_validate,
406 	.power_on	= cdns_dphy_power_on,
407 	.power_off	= cdns_dphy_power_off,
408 };
409 
410 static int cdns_dphy_probe(struct platform_device *pdev)
411 {
412 	struct phy_provider *phy_provider;
413 	struct cdns_dphy *dphy;
414 	int ret;
415 
416 	dphy = devm_kzalloc(&pdev->dev, sizeof(*dphy), GFP_KERNEL);
417 	if (!dphy)
418 		return -ENOMEM;
419 	dev_set_drvdata(&pdev->dev, dphy);
420 
421 	dphy->ops = of_device_get_match_data(&pdev->dev);
422 	if (!dphy->ops)
423 		return -EINVAL;
424 
425 	dphy->regs = devm_platform_ioremap_resource(pdev, 0);
426 	if (IS_ERR(dphy->regs))
427 		return PTR_ERR(dphy->regs);
428 
429 	dphy->psm_clk = devm_clk_get(&pdev->dev, "psm");
430 	if (IS_ERR(dphy->psm_clk))
431 		return PTR_ERR(dphy->psm_clk);
432 
433 	dphy->pll_ref_clk = devm_clk_get(&pdev->dev, "pll_ref");
434 	if (IS_ERR(dphy->pll_ref_clk))
435 		return PTR_ERR(dphy->pll_ref_clk);
436 
437 	if (dphy->ops->probe) {
438 		ret = dphy->ops->probe(dphy);
439 		if (ret)
440 			return ret;
441 	}
442 
443 	dphy->phy = devm_phy_create(&pdev->dev, NULL, &cdns_dphy_ops);
444 	if (IS_ERR(dphy->phy)) {
445 		dev_err(&pdev->dev, "failed to create PHY\n");
446 		if (dphy->ops->remove)
447 			dphy->ops->remove(dphy);
448 		return PTR_ERR(dphy->phy);
449 	}
450 
451 	phy_set_drvdata(dphy->phy, dphy);
452 	phy_provider = devm_of_phy_provider_register(&pdev->dev,
453 						     of_phy_simple_xlate);
454 
455 	return PTR_ERR_OR_ZERO(phy_provider);
456 }
457 
458 static void cdns_dphy_remove(struct platform_device *pdev)
459 {
460 	struct cdns_dphy *dphy = dev_get_drvdata(&pdev->dev);
461 
462 	if (dphy->ops->remove)
463 		dphy->ops->remove(dphy);
464 }
465 
466 static const struct of_device_id cdns_dphy_of_match[] = {
467 	{ .compatible = "cdns,dphy", .data = &ref_dphy_ops },
468 	{ .compatible = "ti,j721e-dphy", .data = &j721e_dphy_ops },
469 	{ /* sentinel */ },
470 };
471 MODULE_DEVICE_TABLE(of, cdns_dphy_of_match);
472 
473 static struct platform_driver cdns_dphy_platform_driver = {
474 	.probe		= cdns_dphy_probe,
475 	.remove_new	= cdns_dphy_remove,
476 	.driver		= {
477 		.name		= "cdns-mipi-dphy",
478 		.of_match_table	= cdns_dphy_of_match,
479 	},
480 };
481 module_platform_driver(cdns_dphy_platform_driver);
482 
483 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@bootlin.com>");
484 MODULE_DESCRIPTION("Cadence MIPI D-PHY Driver");
485 MODULE_LICENSE("GPL");
486