1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) STMicroelectronics SA 2017
4 *
5 * Authors: Philippe Cornu <philippe.cornu@st.com>
6 * Yannick Fertre <yannick.fertre@st.com>
7 */
8
9 #include <linux/clk.h>
10 #include <linux/iopoll.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/regulator/consumer.h>
15
16 #include <video/mipi_display.h>
17
18 #include <drm/bridge/dw_mipi_dsi.h>
19 #include <drm/drm_mipi_dsi.h>
20 #include <drm/drm_print.h>
21
22 #define HWVER_130 0x31333000 /* IP version 1.30 */
23 #define HWVER_131 0x31333100 /* IP version 1.31 */
24
25 /* DSI digital registers & bit definitions */
26 #define DSI_VERSION 0x00
27 #define VERSION GENMASK(31, 8)
28
29 /* DSI wrapper registers & bit definitions */
30 /* Note: registers are named as in the Reference Manual */
31 #define DSI_WCFGR 0x0400 /* Wrapper ConFiGuration Reg */
32 #define WCFGR_DSIM BIT(0) /* DSI Mode */
33 #define WCFGR_COLMUX GENMASK(3, 1) /* COLor MUltipleXing */
34
35 #define DSI_WCR 0x0404 /* Wrapper Control Reg */
36 #define WCR_DSIEN BIT(3) /* DSI ENable */
37
38 #define DSI_WISR 0x040C /* Wrapper Interrupt and Status Reg */
39 #define WISR_PLLLS BIT(8) /* PLL Lock Status */
40 #define WISR_RRS BIT(12) /* Regulator Ready Status */
41
42 #define DSI_WPCR0 0x0418 /* Wrapper Phy Conf Reg 0 */
43 #define WPCR0_UIX4 GENMASK(5, 0) /* Unit Interval X 4 */
44 #define WPCR0_TDDL BIT(16) /* Turn Disable Data Lanes */
45
46 #define DSI_WRPCR 0x0430 /* Wrapper Regulator & Pll Ctrl Reg */
47 #define WRPCR_PLLEN BIT(0) /* PLL ENable */
48 #define WRPCR_NDIV GENMASK(8, 2) /* pll loop DIVision Factor */
49 #define WRPCR_IDF GENMASK(14, 11) /* pll Input Division Factor */
50 #define WRPCR_ODF GENMASK(17, 16) /* pll Output Division Factor */
51 #define WRPCR_REGEN BIT(24) /* REGulator ENable */
52 #define WRPCR_BGREN BIT(28) /* BandGap Reference ENable */
53 #define IDF_MIN 1
54 #define IDF_MAX 7
55 #define NDIV_MIN 10
56 #define NDIV_MAX 125
57 #define ODF_MIN 1
58 #define ODF_MAX 8
59
60 /* dsi color format coding according to the datasheet */
61 enum dsi_color {
62 DSI_RGB565_CONF1,
63 DSI_RGB565_CONF2,
64 DSI_RGB565_CONF3,
65 DSI_RGB666_CONF1,
66 DSI_RGB666_CONF2,
67 DSI_RGB888,
68 };
69
70 #define LANE_MIN_KBPS 31250
71 #define LANE_MAX_KBPS 500000
72
73 /* Sleep & timeout for regulator on/off, pll lock/unlock & fifo empty */
74 #define SLEEP_US 1000
75 #define TIMEOUT_US 200000
76
77 struct dw_mipi_dsi_stm {
78 void __iomem *base;
79 struct clk *pllref_clk;
80 struct dw_mipi_dsi *dsi;
81 u32 hw_version;
82 int lane_min_kbps;
83 int lane_max_kbps;
84 struct regulator *vdd_supply;
85 };
86
dsi_write(struct dw_mipi_dsi_stm * dsi,u32 reg,u32 val)87 static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val)
88 {
89 writel(val, dsi->base + reg);
90 }
91
dsi_read(struct dw_mipi_dsi_stm * dsi,u32 reg)92 static inline u32 dsi_read(struct dw_mipi_dsi_stm *dsi, u32 reg)
93 {
94 return readl(dsi->base + reg);
95 }
96
dsi_set(struct dw_mipi_dsi_stm * dsi,u32 reg,u32 mask)97 static inline void dsi_set(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 mask)
98 {
99 dsi_write(dsi, reg, dsi_read(dsi, reg) | mask);
100 }
101
dsi_clear(struct dw_mipi_dsi_stm * dsi,u32 reg,u32 mask)102 static inline void dsi_clear(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 mask)
103 {
104 dsi_write(dsi, reg, dsi_read(dsi, reg) & ~mask);
105 }
106
dsi_update_bits(struct dw_mipi_dsi_stm * dsi,u32 reg,u32 mask,u32 val)107 static inline void dsi_update_bits(struct dw_mipi_dsi_stm *dsi, u32 reg,
108 u32 mask, u32 val)
109 {
110 dsi_write(dsi, reg, (dsi_read(dsi, reg) & ~mask) | val);
111 }
112
dsi_color_from_mipi(enum mipi_dsi_pixel_format fmt)113 static enum dsi_color dsi_color_from_mipi(enum mipi_dsi_pixel_format fmt)
114 {
115 switch (fmt) {
116 case MIPI_DSI_FMT_RGB888:
117 return DSI_RGB888;
118 case MIPI_DSI_FMT_RGB666:
119 return DSI_RGB666_CONF2;
120 case MIPI_DSI_FMT_RGB666_PACKED:
121 return DSI_RGB666_CONF1;
122 case MIPI_DSI_FMT_RGB565:
123 return DSI_RGB565_CONF1;
124 default:
125 DRM_DEBUG_DRIVER("MIPI color invalid, so we use rgb888\n");
126 }
127 return DSI_RGB888;
128 }
129
dsi_pll_get_clkout_khz(int clkin_khz,int idf,int ndiv,int odf)130 static int dsi_pll_get_clkout_khz(int clkin_khz, int idf, int ndiv, int odf)
131 {
132 int divisor = idf * odf;
133
134 /* prevent from division by 0 */
135 if (!divisor)
136 return 0;
137
138 return DIV_ROUND_CLOSEST(clkin_khz * ndiv, divisor);
139 }
140
dsi_pll_get_params(struct dw_mipi_dsi_stm * dsi,int clkin_khz,int clkout_khz,int * idf,int * ndiv,int * odf)141 static int dsi_pll_get_params(struct dw_mipi_dsi_stm *dsi,
142 int clkin_khz, int clkout_khz,
143 int *idf, int *ndiv, int *odf)
144 {
145 int i, o, n, n_min, n_max;
146 int fvco_min, fvco_max, delta, best_delta; /* all in khz */
147
148 /* Early checks preventing division by 0 & odd results */
149 if (clkin_khz <= 0 || clkout_khz <= 0)
150 return -EINVAL;
151
152 fvco_min = dsi->lane_min_kbps * 2 * ODF_MAX;
153 fvco_max = dsi->lane_max_kbps * 2 * ODF_MIN;
154
155 best_delta = 1000000; /* big started value (1000000khz) */
156
157 for (i = IDF_MIN; i <= IDF_MAX; i++) {
158 /* Compute ndiv range according to Fvco */
159 n_min = ((fvco_min * i) / (2 * clkin_khz)) + 1;
160 n_max = (fvco_max * i) / (2 * clkin_khz);
161
162 /* No need to continue idf loop if we reach ndiv max */
163 if (n_min >= NDIV_MAX)
164 break;
165
166 /* Clamp ndiv to valid values */
167 if (n_min < NDIV_MIN)
168 n_min = NDIV_MIN;
169 if (n_max > NDIV_MAX)
170 n_max = NDIV_MAX;
171
172 for (o = ODF_MIN; o <= ODF_MAX; o *= 2) {
173 n = DIV_ROUND_CLOSEST(i * o * clkout_khz, clkin_khz);
174 /* Check ndiv according to vco range */
175 if (n < n_min || n > n_max)
176 continue;
177 /* Check if new delta is better & saves parameters */
178 delta = dsi_pll_get_clkout_khz(clkin_khz, i, n, o) -
179 clkout_khz;
180 if (delta < 0)
181 delta = -delta;
182 if (delta < best_delta) {
183 *idf = i;
184 *ndiv = n;
185 *odf = o;
186 best_delta = delta;
187 }
188 /* fast return in case of "perfect result" */
189 if (!delta)
190 return 0;
191 }
192 }
193
194 return 0;
195 }
196
dw_mipi_dsi_phy_init(void * priv_data)197 static int dw_mipi_dsi_phy_init(void *priv_data)
198 {
199 struct dw_mipi_dsi_stm *dsi = priv_data;
200 u32 val;
201 int ret;
202
203 /* Enable the regulator */
204 dsi_set(dsi, DSI_WRPCR, WRPCR_REGEN | WRPCR_BGREN);
205 ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_RRS,
206 SLEEP_US, TIMEOUT_US);
207 if (ret)
208 DRM_DEBUG_DRIVER("!TIMEOUT! waiting REGU, let's continue\n");
209
210 /* Enable the DSI PLL & wait for its lock */
211 dsi_set(dsi, DSI_WRPCR, WRPCR_PLLEN);
212 ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_PLLLS,
213 SLEEP_US, TIMEOUT_US);
214 if (ret)
215 DRM_DEBUG_DRIVER("!TIMEOUT! waiting PLL, let's continue\n");
216
217 return 0;
218 }
219
dw_mipi_dsi_phy_power_on(void * priv_data)220 static void dw_mipi_dsi_phy_power_on(void *priv_data)
221 {
222 struct dw_mipi_dsi_stm *dsi = priv_data;
223
224 DRM_DEBUG_DRIVER("\n");
225
226 /* Enable the DSI wrapper */
227 dsi_set(dsi, DSI_WCR, WCR_DSIEN);
228 }
229
dw_mipi_dsi_phy_power_off(void * priv_data)230 static void dw_mipi_dsi_phy_power_off(void *priv_data)
231 {
232 struct dw_mipi_dsi_stm *dsi = priv_data;
233
234 DRM_DEBUG_DRIVER("\n");
235
236 /* Disable the DSI wrapper */
237 dsi_clear(dsi, DSI_WCR, WCR_DSIEN);
238 }
239
240 static int
dw_mipi_dsi_get_lane_mbps(void * priv_data,const struct drm_display_mode * mode,unsigned long mode_flags,u32 lanes,u32 format,unsigned int * lane_mbps)241 dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct drm_display_mode *mode,
242 unsigned long mode_flags, u32 lanes, u32 format,
243 unsigned int *lane_mbps)
244 {
245 struct dw_mipi_dsi_stm *dsi = priv_data;
246 unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz;
247 int ret, bpp;
248 u32 val;
249
250 /* Update lane capabilities according to hw version */
251 dsi->lane_min_kbps = LANE_MIN_KBPS;
252 dsi->lane_max_kbps = LANE_MAX_KBPS;
253 if (dsi->hw_version == HWVER_131) {
254 dsi->lane_min_kbps *= 2;
255 dsi->lane_max_kbps *= 2;
256 }
257
258 pll_in_khz = (unsigned int)(clk_get_rate(dsi->pllref_clk) / 1000);
259
260 /* Compute requested pll out */
261 bpp = mipi_dsi_pixel_format_to_bpp(format);
262 pll_out_khz = mode->clock * bpp / lanes;
263
264 /* Add 20% to pll out to be higher than pixel bw (burst mode only) */
265 if (mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
266 pll_out_khz = (pll_out_khz * 12) / 10;
267
268 if (pll_out_khz > dsi->lane_max_kbps) {
269 pll_out_khz = dsi->lane_max_kbps;
270 DRM_WARN("Warning max phy mbps is used\n");
271 }
272 if (pll_out_khz < dsi->lane_min_kbps) {
273 pll_out_khz = dsi->lane_min_kbps;
274 DRM_WARN("Warning min phy mbps is used\n");
275 }
276
277 /* Compute best pll parameters */
278 idf = 0;
279 ndiv = 0;
280 odf = 0;
281 ret = dsi_pll_get_params(dsi, pll_in_khz, pll_out_khz,
282 &idf, &ndiv, &odf);
283 if (ret)
284 DRM_WARN("Warning dsi_pll_get_params(): bad params\n");
285
286 /* Get the adjusted pll out value */
287 pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);
288
289 /* Set the PLL division factors */
290 dsi_update_bits(dsi, DSI_WRPCR, WRPCR_NDIV | WRPCR_IDF | WRPCR_ODF,
291 (ndiv << 2) | (idf << 11) | ((ffs(odf) - 1) << 16));
292
293 /* Compute uix4 & set the bit period in high-speed mode */
294 val = 4000000 / pll_out_khz;
295 dsi_update_bits(dsi, DSI_WPCR0, WPCR0_UIX4, val);
296
297 /* Select video mode by resetting DSIM bit */
298 dsi_clear(dsi, DSI_WCFGR, WCFGR_DSIM);
299
300 /* Select the color coding */
301 dsi_update_bits(dsi, DSI_WCFGR, WCFGR_COLMUX,
302 dsi_color_from_mipi(format) << 1);
303
304 *lane_mbps = pll_out_khz / 1000;
305
306 DRM_DEBUG_DRIVER("pll_in %ukHz pll_out %ukHz lane_mbps %uMHz\n",
307 pll_in_khz, pll_out_khz, *lane_mbps);
308
309 return 0;
310 }
311
312 static int
dw_mipi_dsi_phy_get_timing(void * priv_data,unsigned int lane_mbps,struct dw_mipi_dsi_dphy_timing * timing)313 dw_mipi_dsi_phy_get_timing(void *priv_data, unsigned int lane_mbps,
314 struct dw_mipi_dsi_dphy_timing *timing)
315 {
316 timing->clk_hs2lp = 0x40;
317 timing->clk_lp2hs = 0x40;
318 timing->data_hs2lp = 0x40;
319 timing->data_lp2hs = 0x40;
320
321 return 0;
322 }
323
324 static const struct dw_mipi_dsi_phy_ops dw_mipi_dsi_stm_phy_ops = {
325 .init = dw_mipi_dsi_phy_init,
326 .power_on = dw_mipi_dsi_phy_power_on,
327 .power_off = dw_mipi_dsi_phy_power_off,
328 .get_lane_mbps = dw_mipi_dsi_get_lane_mbps,
329 .get_timing = dw_mipi_dsi_phy_get_timing,
330 };
331
332 static struct dw_mipi_dsi_plat_data dw_mipi_dsi_stm_plat_data = {
333 .max_data_lanes = 2,
334 .phy_ops = &dw_mipi_dsi_stm_phy_ops,
335 };
336
337 static const struct of_device_id dw_mipi_dsi_stm_dt_ids[] = {
338 { .compatible = "st,stm32-dsi", .data = &dw_mipi_dsi_stm_plat_data, },
339 { },
340 };
341 MODULE_DEVICE_TABLE(of, dw_mipi_dsi_stm_dt_ids);
342
dw_mipi_dsi_stm_probe(struct platform_device * pdev)343 static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
344 {
345 struct device *dev = &pdev->dev;
346 struct dw_mipi_dsi_stm *dsi;
347 struct clk *pclk;
348 struct resource *res;
349 int ret;
350
351 dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
352 if (!dsi)
353 return -ENOMEM;
354
355 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
356 dsi->base = devm_ioremap_resource(dev, res);
357 if (IS_ERR(dsi->base)) {
358 ret = PTR_ERR(dsi->base);
359 DRM_ERROR("Unable to get dsi registers %d\n", ret);
360 return ret;
361 }
362
363 dsi->vdd_supply = devm_regulator_get(dev, "phy-dsi");
364 if (IS_ERR(dsi->vdd_supply)) {
365 ret = PTR_ERR(dsi->vdd_supply);
366 if (ret != -EPROBE_DEFER)
367 DRM_ERROR("Failed to request regulator: %d\n", ret);
368 return ret;
369 }
370
371 ret = regulator_enable(dsi->vdd_supply);
372 if (ret) {
373 DRM_ERROR("Failed to enable regulator: %d\n", ret);
374 return ret;
375 }
376
377 dsi->pllref_clk = devm_clk_get(dev, "ref");
378 if (IS_ERR(dsi->pllref_clk)) {
379 ret = PTR_ERR(dsi->pllref_clk);
380 if (ret != -EPROBE_DEFER)
381 DRM_ERROR("Unable to get pll reference clock: %d\n",
382 ret);
383 goto err_clk_get;
384 }
385
386 ret = clk_prepare_enable(dsi->pllref_clk);
387 if (ret) {
388 DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
389 goto err_clk_get;
390 }
391
392 pclk = devm_clk_get(dev, "pclk");
393 if (IS_ERR(pclk)) {
394 ret = PTR_ERR(pclk);
395 DRM_ERROR("Unable to get peripheral clock: %d\n", ret);
396 goto err_dsi_probe;
397 }
398
399 ret = clk_prepare_enable(pclk);
400 if (ret) {
401 DRM_ERROR("%s: Failed to enable peripheral clk\n", __func__);
402 goto err_dsi_probe;
403 }
404
405 dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
406 clk_disable_unprepare(pclk);
407
408 if (dsi->hw_version != HWVER_130 && dsi->hw_version != HWVER_131) {
409 ret = -ENODEV;
410 DRM_ERROR("bad dsi hardware version\n");
411 goto err_dsi_probe;
412 }
413
414 dw_mipi_dsi_stm_plat_data.base = dsi->base;
415 dw_mipi_dsi_stm_plat_data.priv_data = dsi;
416
417 platform_set_drvdata(pdev, dsi);
418
419 dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
420 if (IS_ERR(dsi->dsi)) {
421 ret = PTR_ERR(dsi->dsi);
422 DRM_ERROR("Failed to initialize mipi dsi host: %d\n", ret);
423 goto err_dsi_probe;
424 }
425
426 return 0;
427
428 err_dsi_probe:
429 clk_disable_unprepare(dsi->pllref_clk);
430 err_clk_get:
431 regulator_disable(dsi->vdd_supply);
432
433 return ret;
434 }
435
dw_mipi_dsi_stm_remove(struct platform_device * pdev)436 static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
437 {
438 struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);
439
440 dw_mipi_dsi_remove(dsi->dsi);
441 clk_disable_unprepare(dsi->pllref_clk);
442 regulator_disable(dsi->vdd_supply);
443
444 return 0;
445 }
446
dw_mipi_dsi_stm_suspend(struct device * dev)447 static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
448 {
449 struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
450
451 DRM_DEBUG_DRIVER("\n");
452
453 clk_disable_unprepare(dsi->pllref_clk);
454 regulator_disable(dsi->vdd_supply);
455
456 return 0;
457 }
458
dw_mipi_dsi_stm_resume(struct device * dev)459 static int __maybe_unused dw_mipi_dsi_stm_resume(struct device *dev)
460 {
461 struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
462 int ret;
463
464 DRM_DEBUG_DRIVER("\n");
465
466 ret = regulator_enable(dsi->vdd_supply);
467 if (ret) {
468 DRM_ERROR("Failed to enable regulator: %d\n", ret);
469 return ret;
470 }
471
472 ret = clk_prepare_enable(dsi->pllref_clk);
473 if (ret) {
474 regulator_disable(dsi->vdd_supply);
475 DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
476 return ret;
477 }
478
479 return 0;
480 }
481
482 static const struct dev_pm_ops dw_mipi_dsi_stm_pm_ops = {
483 SET_SYSTEM_SLEEP_PM_OPS(dw_mipi_dsi_stm_suspend,
484 dw_mipi_dsi_stm_resume)
485 };
486
487 static struct platform_driver dw_mipi_dsi_stm_driver = {
488 .probe = dw_mipi_dsi_stm_probe,
489 .remove = dw_mipi_dsi_stm_remove,
490 .driver = {
491 .of_match_table = dw_mipi_dsi_stm_dt_ids,
492 .name = "stm32-display-dsi",
493 .pm = &dw_mipi_dsi_stm_pm_ops,
494 },
495 };
496
497 module_platform_driver(dw_mipi_dsi_stm_driver);
498
499 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
500 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
501 MODULE_DESCRIPTION("STMicroelectronics DW MIPI DSI host controller driver");
502 MODULE_LICENSE("GPL v2");
503