xref: /openbmc/linux/drivers/phy/cadence/cdns-dphy.c (revision ea15d3bd)
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_address.h>
13 #include <linux/of_device.h>
14 #include <linux/platform_device.h>
15 #include <linux/reset.h>
16 
17 #include <linux/phy/phy.h>
18 #include <linux/phy/phy-mipi-dphy.h>
19 
20 #define REG_WAKEUP_TIME_NS		800
21 #define DPHY_PLL_RATE_HZ		108000000
22 #define POLL_TIMEOUT_US			1000
23 
24 /* DPHY registers */
25 #define DPHY_PMA_CMN(reg)		(reg)
26 #define DPHY_PMA_LCLK(reg)		(0x100 + (reg))
27 #define DPHY_PMA_LDATA(lane, reg)	(0x200 + ((lane) * 0x100) + (reg))
28 #define DPHY_PMA_RCLK(reg)		(0x600 + (reg))
29 #define DPHY_PMA_RDATA(lane, reg)	(0x700 + ((lane) * 0x100) + (reg))
30 #define DPHY_PCS(reg)			(0xb00 + (reg))
31 
32 #define DPHY_CMN_SSM			DPHY_PMA_CMN(0x20)
33 #define DPHY_CMN_SSM_EN			BIT(0)
34 #define DPHY_CMN_TX_MODE_EN		BIT(9)
35 
36 #define DPHY_CMN_PWM			DPHY_PMA_CMN(0x40)
37 #define DPHY_CMN_PWM_DIV(x)		((x) << 20)
38 #define DPHY_CMN_PWM_LOW(x)		((x) << 10)
39 #define DPHY_CMN_PWM_HIGH(x)		(x)
40 
41 #define DPHY_CMN_FBDIV			DPHY_PMA_CMN(0x4c)
42 #define DPHY_CMN_FBDIV_VAL(low, high)	(((high) << 11) | ((low) << 22))
43 #define DPHY_CMN_FBDIV_FROM_REG		(BIT(10) | BIT(21))
44 
45 #define DPHY_CMN_OPIPDIV		DPHY_PMA_CMN(0x50)
46 #define DPHY_CMN_IPDIV_FROM_REG		BIT(0)
47 #define DPHY_CMN_IPDIV(x)		((x) << 1)
48 #define DPHY_CMN_OPDIV_FROM_REG		BIT(6)
49 #define DPHY_CMN_OPDIV(x)		((x) << 7)
50 
51 #define DPHY_BAND_CFG			DPHY_PCS(0x0)
52 #define DPHY_BAND_CFG_LEFT_BAND		GENMASK(4, 0)
53 #define DPHY_BAND_CFG_RIGHT_BAND	GENMASK(9, 5)
54 
55 #define DPHY_PSM_CFG			DPHY_PCS(0x4)
56 #define DPHY_PSM_CFG_FROM_REG		BIT(0)
57 #define DPHY_PSM_CLK_DIV(x)		((x) << 1)
58 
59 #define DSI_HBP_FRAME_OVERHEAD		12
60 #define DSI_HSA_FRAME_OVERHEAD		14
61 #define DSI_HFP_FRAME_OVERHEAD		6
62 #define DSI_HSS_VSS_VSE_FRAME_OVERHEAD	4
63 #define DSI_BLANKING_FRAME_OVERHEAD	6
64 #define DSI_NULL_FRAME_OVERHEAD		6
65 #define DSI_EOT_PKT_SIZE		4
66 
67 #define DPHY_TX_J721E_WIZ_PLL_CTRL	0xF04
68 #define DPHY_TX_J721E_WIZ_STATUS	0xF08
69 #define DPHY_TX_J721E_WIZ_RST_CTRL	0xF0C
70 #define DPHY_TX_J721E_WIZ_PSM_FREQ	0xF10
71 
72 #define DPHY_TX_J721E_WIZ_IPDIV		GENMASK(4, 0)
73 #define DPHY_TX_J721E_WIZ_OPDIV		GENMASK(13, 8)
74 #define DPHY_TX_J721E_WIZ_FBDIV		GENMASK(25, 16)
75 #define DPHY_TX_J721E_WIZ_LANE_RSTB	BIT(31)
76 #define DPHY_TX_WIZ_PLL_LOCK		BIT(31)
77 #define DPHY_TX_WIZ_O_CMN_READY		BIT(31)
78 
79 struct cdns_dphy_cfg {
80 	u8 pll_ipdiv;
81 	u8 pll_opdiv;
82 	u16 pll_fbdiv;
83 	unsigned int nlanes;
84 };
85 
86 enum cdns_dphy_clk_lane_cfg {
87 	DPHY_CLK_CFG_LEFT_DRIVES_ALL = 0,
88 	DPHY_CLK_CFG_LEFT_DRIVES_RIGHT = 1,
89 	DPHY_CLK_CFG_LEFT_DRIVES_LEFT = 2,
90 	DPHY_CLK_CFG_RIGHT_DRIVES_ALL = 3,
91 };
92 
93 struct cdns_dphy;
94 struct cdns_dphy_ops {
95 	int (*probe)(struct cdns_dphy *dphy);
96 	void (*remove)(struct cdns_dphy *dphy);
97 	void (*set_psm_div)(struct cdns_dphy *dphy, u8 div);
98 	void (*set_clk_lane_cfg)(struct cdns_dphy *dphy,
99 				 enum cdns_dphy_clk_lane_cfg cfg);
100 	void (*set_pll_cfg)(struct cdns_dphy *dphy,
101 			    const struct cdns_dphy_cfg *cfg);
102 	unsigned long (*get_wakeup_time_ns)(struct cdns_dphy *dphy);
103 };
104 
105 struct cdns_dphy {
106 	struct cdns_dphy_cfg cfg;
107 	void __iomem *regs;
108 	struct clk *psm_clk;
109 	struct clk *pll_ref_clk;
110 	const struct cdns_dphy_ops *ops;
111 	struct phy *phy;
112 };
113 
114 /* Order of bands is important since the index is the band number. */
115 static const unsigned int tx_bands[] = {
116 	80, 100, 120, 160, 200, 240, 320, 390, 450, 510, 560, 640, 690, 770,
117 	870, 950, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2500
118 };
119 
120 static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
121 				     struct cdns_dphy_cfg *cfg,
122 				     struct phy_configure_opts_mipi_dphy *opts,
123 				     unsigned int *dsi_hfp_ext)
124 {
125 	unsigned long pll_ref_hz = clk_get_rate(dphy->pll_ref_clk);
126 	u64 dlane_bps;
127 
128 	memset(cfg, 0, sizeof(*cfg));
129 
130 	if (pll_ref_hz < 9600000 || pll_ref_hz >= 150000000)
131 		return -EINVAL;
132 	else if (pll_ref_hz < 19200000)
133 		cfg->pll_ipdiv = 1;
134 	else if (pll_ref_hz < 38400000)
135 		cfg->pll_ipdiv = 2;
136 	else if (pll_ref_hz < 76800000)
137 		cfg->pll_ipdiv = 4;
138 	else
139 		cfg->pll_ipdiv = 8;
140 
141 	dlane_bps = opts->hs_clk_rate;
142 
143 	if (dlane_bps > 2500000000UL || dlane_bps < 160000000UL)
144 		return -EINVAL;
145 	else if (dlane_bps >= 1250000000)
146 		cfg->pll_opdiv = 1;
147 	else if (dlane_bps >= 630000000)
148 		cfg->pll_opdiv = 2;
149 	else if (dlane_bps >= 320000000)
150 		cfg->pll_opdiv = 4;
151 	else if (dlane_bps >= 160000000)
152 		cfg->pll_opdiv = 8;
153 
154 	cfg->pll_fbdiv = DIV_ROUND_UP_ULL(dlane_bps * 2 * cfg->pll_opdiv *
155 					  cfg->pll_ipdiv,
156 					  pll_ref_hz);
157 
158 	return 0;
159 }
160 
161 static int cdns_dphy_setup_psm(struct cdns_dphy *dphy)
162 {
163 	unsigned long psm_clk_hz = clk_get_rate(dphy->psm_clk);
164 	unsigned long psm_div;
165 
166 	if (!psm_clk_hz || psm_clk_hz > 100000000)
167 		return -EINVAL;
168 
169 	psm_div = DIV_ROUND_CLOSEST(psm_clk_hz, 1000000);
170 	if (dphy->ops->set_psm_div)
171 		dphy->ops->set_psm_div(dphy, psm_div);
172 
173 	return 0;
174 }
175 
176 static void cdns_dphy_set_clk_lane_cfg(struct cdns_dphy *dphy,
177 				       enum cdns_dphy_clk_lane_cfg cfg)
178 {
179 	if (dphy->ops->set_clk_lane_cfg)
180 		dphy->ops->set_clk_lane_cfg(dphy, cfg);
181 }
182 
183 static void cdns_dphy_set_pll_cfg(struct cdns_dphy *dphy,
184 				  const struct cdns_dphy_cfg *cfg)
185 {
186 	if (dphy->ops->set_pll_cfg)
187 		dphy->ops->set_pll_cfg(dphy, cfg);
188 }
189 
190 static unsigned long cdns_dphy_get_wakeup_time_ns(struct cdns_dphy *dphy)
191 {
192 	return dphy->ops->get_wakeup_time_ns(dphy);
193 }
194 
195 static unsigned long cdns_dphy_ref_get_wakeup_time_ns(struct cdns_dphy *dphy)
196 {
197 	/* Default wakeup time is 800 ns (in a simulated environment). */
198 	return 800;
199 }
200 
201 static void cdns_dphy_ref_set_pll_cfg(struct cdns_dphy *dphy,
202 				      const struct cdns_dphy_cfg *cfg)
203 {
204 	u32 fbdiv_low, fbdiv_high;
205 
206 	fbdiv_low = (cfg->pll_fbdiv / 4) - 2;
207 	fbdiv_high = cfg->pll_fbdiv - fbdiv_low - 2;
208 
209 	writel(DPHY_CMN_IPDIV_FROM_REG | DPHY_CMN_OPDIV_FROM_REG |
210 	       DPHY_CMN_IPDIV(cfg->pll_ipdiv) |
211 	       DPHY_CMN_OPDIV(cfg->pll_opdiv),
212 	       dphy->regs + DPHY_CMN_OPIPDIV);
213 	writel(DPHY_CMN_FBDIV_FROM_REG |
214 	       DPHY_CMN_FBDIV_VAL(fbdiv_low, fbdiv_high),
215 	       dphy->regs + DPHY_CMN_FBDIV);
216 	writel(DPHY_CMN_PWM_HIGH(6) | DPHY_CMN_PWM_LOW(0x101) |
217 	       DPHY_CMN_PWM_DIV(0x8),
218 	       dphy->regs + DPHY_CMN_PWM);
219 }
220 
221 static void cdns_dphy_ref_set_psm_div(struct cdns_dphy *dphy, u8 div)
222 {
223 	writel(DPHY_PSM_CFG_FROM_REG | DPHY_PSM_CLK_DIV(div),
224 	       dphy->regs + DPHY_PSM_CFG);
225 }
226 
227 static unsigned long cdns_dphy_j721e_get_wakeup_time_ns(struct cdns_dphy *dphy)
228 {
229 	/* Minimum wakeup time as per MIPI D-PHY spec v1.2 */
230 	return 1000000;
231 }
232 
233 static void cdns_dphy_j721e_set_pll_cfg(struct cdns_dphy *dphy,
234 					const struct cdns_dphy_cfg *cfg)
235 {
236 	u32 status;
237 
238 	/*
239 	 * set the PWM and PLL Byteclk divider settings to recommended values
240 	 * which is same as that of in ref ops
241 	 */
242 	writel(DPHY_CMN_PWM_HIGH(6) | DPHY_CMN_PWM_LOW(0x101) |
243 	       DPHY_CMN_PWM_DIV(0x8),
244 	       dphy->regs + DPHY_CMN_PWM);
245 
246 	writel((FIELD_PREP(DPHY_TX_J721E_WIZ_IPDIV, cfg->pll_ipdiv) |
247 		FIELD_PREP(DPHY_TX_J721E_WIZ_OPDIV, cfg->pll_opdiv) |
248 		FIELD_PREP(DPHY_TX_J721E_WIZ_FBDIV, cfg->pll_fbdiv)),
249 		dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL);
250 
251 	writel(DPHY_TX_J721E_WIZ_LANE_RSTB,
252 	       dphy->regs + DPHY_TX_J721E_WIZ_RST_CTRL);
253 
254 	readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL, status,
255 			   (status & DPHY_TX_WIZ_PLL_LOCK), 0, POLL_TIMEOUT_US);
256 
257 	readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_STATUS, status,
258 			   (status & DPHY_TX_WIZ_O_CMN_READY), 0,
259 			   POLL_TIMEOUT_US);
260 }
261 
262 static void cdns_dphy_j721e_set_psm_div(struct cdns_dphy *dphy, u8 div)
263 {
264 	writel(div, dphy->regs + DPHY_TX_J721E_WIZ_PSM_FREQ);
265 }
266 
267 /*
268  * This is the reference implementation of DPHY hooks. Specific integration of
269  * this IP may have to re-implement some of them depending on how they decided
270  * to wire things in the SoC.
271  */
272 static const struct cdns_dphy_ops ref_dphy_ops = {
273 	.get_wakeup_time_ns = cdns_dphy_ref_get_wakeup_time_ns,
274 	.set_pll_cfg = cdns_dphy_ref_set_pll_cfg,
275 	.set_psm_div = cdns_dphy_ref_set_psm_div,
276 };
277 
278 static const struct cdns_dphy_ops j721e_dphy_ops = {
279 	.get_wakeup_time_ns = cdns_dphy_j721e_get_wakeup_time_ns,
280 	.set_pll_cfg = cdns_dphy_j721e_set_pll_cfg,
281 	.set_psm_div = cdns_dphy_j721e_set_psm_div,
282 };
283 
284 static int cdns_dphy_config_from_opts(struct phy *phy,
285 				      struct phy_configure_opts_mipi_dphy *opts,
286 				      struct cdns_dphy_cfg *cfg)
287 {
288 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
289 	unsigned int dsi_hfp_ext = 0;
290 	int ret;
291 
292 	ret = phy_mipi_dphy_config_validate(opts);
293 	if (ret)
294 		return ret;
295 
296 	ret = cdns_dsi_get_dphy_pll_cfg(dphy, cfg,
297 					opts, &dsi_hfp_ext);
298 	if (ret)
299 		return ret;
300 
301 	opts->wakeup = cdns_dphy_get_wakeup_time_ns(dphy) / 1000;
302 
303 	return 0;
304 }
305 
306 static int cdns_dphy_tx_get_band_ctrl(unsigned long hs_clk_rate)
307 {
308 	unsigned int rate;
309 	int i;
310 
311 	rate = hs_clk_rate / 1000000UL;
312 
313 	if (rate < tx_bands[0])
314 		return -EOPNOTSUPP;
315 
316 	for (i = 0; i < ARRAY_SIZE(tx_bands) - 1; i++) {
317 		if (rate >= tx_bands[i] && rate < tx_bands[i + 1])
318 			return i;
319 	}
320 
321 	return -EOPNOTSUPP;
322 }
323 
324 static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
325 			      union phy_configure_opts *opts)
326 {
327 	struct cdns_dphy_cfg cfg = { 0 };
328 
329 	if (mode != PHY_MODE_MIPI_DPHY)
330 		return -EINVAL;
331 
332 	return cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
333 }
334 
335 static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
336 {
337 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
338 	struct cdns_dphy_cfg cfg = { 0 };
339 	int ret, band_ctrl;
340 	unsigned int reg;
341 
342 	ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
343 	if (ret)
344 		return ret;
345 
346 	/*
347 	 * Configure the internal PSM clk divider so that the DPHY has a
348 	 * 1MHz clk (or something close).
349 	 */
350 	ret = cdns_dphy_setup_psm(dphy);
351 	if (ret)
352 		return ret;
353 
354 	/*
355 	 * Configure attach clk lanes to data lanes: the DPHY has 2 clk lanes
356 	 * and 8 data lanes, each clk lane can be attache different set of
357 	 * data lanes. The 2 groups are named 'left' and 'right', so here we
358 	 * just say that we want the 'left' clk lane to drive the 'left' data
359 	 * lanes.
360 	 */
361 	cdns_dphy_set_clk_lane_cfg(dphy, DPHY_CLK_CFG_LEFT_DRIVES_LEFT);
362 
363 	/*
364 	 * Configure the DPHY PLL that will be used to generate the TX byte
365 	 * clk.
366 	 */
367 	cdns_dphy_set_pll_cfg(dphy, &cfg);
368 
369 	band_ctrl = cdns_dphy_tx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
370 	if (band_ctrl < 0)
371 		return band_ctrl;
372 
373 	reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
374 	      FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
375 	writel(reg, dphy->regs + DPHY_BAND_CFG);
376 
377 	return 0;
378 }
379 
380 static int cdns_dphy_power_on(struct phy *phy)
381 {
382 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
383 
384 	clk_prepare_enable(dphy->psm_clk);
385 	clk_prepare_enable(dphy->pll_ref_clk);
386 
387 	/* Start TX state machine. */
388 	writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN,
389 	       dphy->regs + DPHY_CMN_SSM);
390 
391 	return 0;
392 }
393 
394 static int cdns_dphy_power_off(struct phy *phy)
395 {
396 	struct cdns_dphy *dphy = phy_get_drvdata(phy);
397 
398 	clk_disable_unprepare(dphy->pll_ref_clk);
399 	clk_disable_unprepare(dphy->psm_clk);
400 
401 	return 0;
402 }
403 
404 static const struct phy_ops cdns_dphy_ops = {
405 	.configure	= cdns_dphy_configure,
406 	.validate	= cdns_dphy_validate,
407 	.power_on	= cdns_dphy_power_on,
408 	.power_off	= cdns_dphy_power_off,
409 };
410 
411 static int cdns_dphy_probe(struct platform_device *pdev)
412 {
413 	struct phy_provider *phy_provider;
414 	struct cdns_dphy *dphy;
415 	int ret;
416 
417 	dphy = devm_kzalloc(&pdev->dev, sizeof(*dphy), GFP_KERNEL);
418 	if (!dphy)
419 		return -ENOMEM;
420 	dev_set_drvdata(&pdev->dev, dphy);
421 
422 	dphy->ops = of_device_get_match_data(&pdev->dev);
423 	if (!dphy->ops)
424 		return -EINVAL;
425 
426 	dphy->regs = devm_platform_ioremap_resource(pdev, 0);
427 	if (IS_ERR(dphy->regs))
428 		return PTR_ERR(dphy->regs);
429 
430 	dphy->psm_clk = devm_clk_get(&pdev->dev, "psm");
431 	if (IS_ERR(dphy->psm_clk))
432 		return PTR_ERR(dphy->psm_clk);
433 
434 	dphy->pll_ref_clk = devm_clk_get(&pdev->dev, "pll_ref");
435 	if (IS_ERR(dphy->pll_ref_clk))
436 		return PTR_ERR(dphy->pll_ref_clk);
437 
438 	if (dphy->ops->probe) {
439 		ret = dphy->ops->probe(dphy);
440 		if (ret)
441 			return ret;
442 	}
443 
444 	dphy->phy = devm_phy_create(&pdev->dev, NULL, &cdns_dphy_ops);
445 	if (IS_ERR(dphy->phy)) {
446 		dev_err(&pdev->dev, "failed to create PHY\n");
447 		if (dphy->ops->remove)
448 			dphy->ops->remove(dphy);
449 		return PTR_ERR(dphy->phy);
450 	}
451 
452 	phy_set_drvdata(dphy->phy, dphy);
453 	phy_provider = devm_of_phy_provider_register(&pdev->dev,
454 						     of_phy_simple_xlate);
455 
456 	return PTR_ERR_OR_ZERO(phy_provider);
457 }
458 
459 static int cdns_dphy_remove(struct platform_device *pdev)
460 {
461 	struct cdns_dphy *dphy = dev_get_drvdata(&pdev->dev);
462 
463 	if (dphy->ops->remove)
464 		dphy->ops->remove(dphy);
465 
466 	return 0;
467 }
468 
469 static const struct of_device_id cdns_dphy_of_match[] = {
470 	{ .compatible = "cdns,dphy", .data = &ref_dphy_ops },
471 	{ .compatible = "ti,j721e-dphy", .data = &j721e_dphy_ops },
472 	{ /* sentinel */ },
473 };
474 MODULE_DEVICE_TABLE(of, cdns_dphy_of_match);
475 
476 static struct platform_driver cdns_dphy_platform_driver = {
477 	.probe		= cdns_dphy_probe,
478 	.remove		= cdns_dphy_remove,
479 	.driver		= {
480 		.name		= "cdns-mipi-dphy",
481 		.of_match_table	= cdns_dphy_of_match,
482 	},
483 };
484 module_platform_driver(cdns_dphy_platform_driver);
485 
486 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@bootlin.com>");
487 MODULE_DESCRIPTION("Cadence MIPI D-PHY Driver");
488 MODULE_LICENSE("GPL");
489