1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Novena video output support
4  *
5  * IT6251 code based on code Copyright (C) 2014 Sean Cross
6  * from https://github.com/xobs/novena-linux.git commit
7  * 3d85836ee1377d445531928361809612aa0a18db
8  *
9  * Copyright (C) 2014 Marek Vasut <marex@denx.de>
10  */
11 
12 #include <common.h>
13 #include <linux/errno.h>
14 #include <asm/gpio.h>
15 #include <asm/io.h>
16 #include <asm/arch/clock.h>
17 #include <asm/arch/crm_regs.h>
18 #include <asm/arch/imx-regs.h>
19 #include <asm/arch/iomux.h>
20 #include <asm/arch/mxc_hdmi.h>
21 #include <asm/arch/sys_proto.h>
22 #include <asm/mach-imx/iomux-v3.h>
23 #include <asm/mach-imx/mxc_i2c.h>
24 #include <asm/mach-imx/video.h>
25 #include <i2c.h>
26 #include <input.h>
27 #include <ipu_pixfmt.h>
28 #include <linux/fb.h>
29 #include <linux/input.h>
30 #include <malloc.h>
31 #include <stdio_dev.h>
32 
33 #include "novena.h"
34 
35 #define IT6251_VENDOR_ID_LOW				0x00
36 #define IT6251_VENDOR_ID_HIGH				0x01
37 #define IT6251_DEVICE_ID_LOW				0x02
38 #define IT6251_DEVICE_ID_HIGH				0x03
39 #define IT6251_SYSTEM_STATUS				0x0d
40 #define IT6251_SYSTEM_STATUS_RINTSTATUS			(1 << 0)
41 #define IT6251_SYSTEM_STATUS_RHPDSTATUS			(1 << 1)
42 #define IT6251_SYSTEM_STATUS_RVIDEOSTABLE		(1 << 2)
43 #define IT6251_SYSTEM_STATUS_RPLL_IOLOCK		(1 << 3)
44 #define IT6251_SYSTEM_STATUS_RPLL_XPLOCK		(1 << 4)
45 #define IT6251_SYSTEM_STATUS_RPLL_SPLOCK		(1 << 5)
46 #define IT6251_SYSTEM_STATUS_RAUXFREQ_LOCK		(1 << 6)
47 #define IT6251_REF_STATE				0x0e
48 #define IT6251_REF_STATE_MAIN_LINK_DISABLED		(1 << 0)
49 #define IT6251_REF_STATE_AUX_CHANNEL_READ		(1 << 1)
50 #define IT6251_REF_STATE_CR_PATTERN			(1 << 2)
51 #define IT6251_REF_STATE_EQ_PATTERN			(1 << 3)
52 #define IT6251_REF_STATE_NORMAL_OPERATION		(1 << 4)
53 #define IT6251_REF_STATE_MUTED				(1 << 5)
54 
55 #define IT6251_REG_PCLK_CNT_LOW				0x57
56 #define IT6251_REG_PCLK_CNT_HIGH			0x58
57 
58 #define IT6521_RETRY_MAX				20
59 
it6251_is_stable(void)60 static int it6251_is_stable(void)
61 {
62 	const unsigned int caddr = NOVENA_IT6251_CHIPADDR;
63 	const unsigned int laddr = NOVENA_IT6251_LVDSADDR;
64 	int status;
65 	int clkcnt;
66 	int rpclkcnt;
67 	int refstate;
68 
69 	rpclkcnt = (i2c_reg_read(caddr, 0x13) & 0xff) |
70 		   ((i2c_reg_read(caddr, 0x14) << 8) & 0x0f00);
71 	debug("RPCLKCnt: %d\n", rpclkcnt);
72 
73 	status = i2c_reg_read(caddr, IT6251_SYSTEM_STATUS);
74 	debug("System status: 0x%02x\n", status);
75 
76 	clkcnt = (i2c_reg_read(laddr, IT6251_REG_PCLK_CNT_LOW) & 0xff) |
77 		 ((i2c_reg_read(laddr, IT6251_REG_PCLK_CNT_HIGH) << 8) &
78 		  0x0f00);
79 	debug("Clock: 0x%02x\n", clkcnt);
80 
81 	refstate = i2c_reg_read(laddr, IT6251_REF_STATE);
82 	debug("Ref Link State: 0x%02x\n", refstate);
83 
84 	if ((refstate & 0x1f) != 0)
85 		return 0;
86 
87 	/* If video is muted, that's a failure */
88 	if (refstate & IT6251_REF_STATE_MUTED)
89 		return 0;
90 
91 	if (!(status & IT6251_SYSTEM_STATUS_RVIDEOSTABLE))
92 		return 0;
93 
94 	return 1;
95 }
96 
it6251_ready(void)97 static int it6251_ready(void)
98 {
99 	const unsigned int caddr = NOVENA_IT6251_CHIPADDR;
100 
101 	/* Test if the IT6251 came out of reset by reading ID regs. */
102 	if (i2c_reg_read(caddr, IT6251_VENDOR_ID_LOW) != 0x15)
103 		return 0;
104 	if (i2c_reg_read(caddr, IT6251_VENDOR_ID_HIGH) != 0xca)
105 		return 0;
106 	if (i2c_reg_read(caddr, IT6251_DEVICE_ID_LOW) != 0x51)
107 		return 0;
108 	if (i2c_reg_read(caddr, IT6251_DEVICE_ID_HIGH) != 0x62)
109 		return 0;
110 
111 	return 1;
112 }
113 
it6251_program_regs(void)114 static void it6251_program_regs(void)
115 {
116 	const unsigned int caddr = NOVENA_IT6251_CHIPADDR;
117 	const unsigned int laddr = NOVENA_IT6251_LVDSADDR;
118 
119 	i2c_reg_write(caddr, 0x05, 0x00);
120 	mdelay(1);
121 
122 	/* set LVDSRX address, and enable */
123 	i2c_reg_write(caddr, 0xfd, 0xbc);
124 	i2c_reg_write(caddr, 0xfe, 0x01);
125 
126 	/*
127 	 * LVDSRX
128 	 */
129 	/* This write always fails, because the chip goes into reset */
130 	/* reset LVDSRX */
131 	i2c_reg_write(laddr, 0x05, 0xff);
132 	i2c_reg_write(laddr, 0x05, 0x00);
133 
134 	/* reset LVDSRX PLL */
135 	i2c_reg_write(laddr, 0x3b, 0x42);
136 	i2c_reg_write(laddr, 0x3b, 0x43);
137 
138 	/* something with SSC PLL */
139 	i2c_reg_write(laddr, 0x3c, 0x08);
140 	/* don't swap links, but writing reserved registers */
141 	i2c_reg_write(laddr, 0x0b, 0x88);
142 
143 	/* JEIDA, 8-bit depth  0x11, orig 0x42 */
144 	i2c_reg_write(laddr, 0x2c, 0x01);
145 	/* "reserved" */
146 	i2c_reg_write(laddr, 0x32, 0x04);
147 	/* "reserved" */
148 	i2c_reg_write(laddr, 0x35, 0xe0);
149 	/* "reserved" + clock delay */
150 	i2c_reg_write(laddr, 0x2b, 0x24);
151 
152 	/* reset LVDSRX pix clock */
153 	i2c_reg_write(laddr, 0x05, 0x02);
154 	i2c_reg_write(laddr, 0x05, 0x00);
155 
156 	/*
157 	 * DPTX
158 	 */
159 	/* set for two lane mode, normal op, no swapping, no downspread */
160 	i2c_reg_write(caddr, 0x16, 0x02);
161 
162 	/* some AUX channel EDID magic */
163 	i2c_reg_write(caddr, 0x23, 0x40);
164 
165 	/* power down lanes 3-0 */
166 	i2c_reg_write(caddr, 0x5c, 0xf3);
167 
168 	/* enable DP scrambling, change EQ CR phase */
169 	i2c_reg_write(caddr, 0x5f, 0x06);
170 
171 	/* color mode RGB, pclk/2 */
172 	i2c_reg_write(caddr, 0x60, 0x02);
173 	/* dual pixel input mode, no EO swap, no RGB swap */
174 	i2c_reg_write(caddr, 0x61, 0x04);
175 	/* M444B24 video format */
176 	i2c_reg_write(caddr, 0x62, 0x01);
177 
178 	/* vesa range / not interlace / vsync high / hsync high */
179 	i2c_reg_write(caddr, 0xa0, 0x0F);
180 
181 	/* hpd event timer set to 1.6-ish ms */
182 	i2c_reg_write(caddr, 0xc9, 0xf5);
183 
184 	/* more reserved magic */
185 	i2c_reg_write(caddr, 0xca, 0x4d);
186 	i2c_reg_write(caddr, 0xcb, 0x37);
187 
188 	/* enhanced framing mode, auto video fifo reset, video mute disable */
189 	i2c_reg_write(caddr, 0xd3, 0x03);
190 
191 	/* "vidstmp" and some reserved stuff */
192 	i2c_reg_write(caddr, 0xd4, 0x45);
193 
194 	/* queue number -- reserved */
195 	i2c_reg_write(caddr, 0xe7, 0xa0);
196 	/* info frame packets  and reserved */
197 	i2c_reg_write(caddr, 0xe8, 0x33);
198 	/* more AVI stuff */
199 	i2c_reg_write(caddr, 0xec, 0x00);
200 
201 	/* select PC master reg for aux channel? */
202 	i2c_reg_write(caddr, 0x23, 0x42);
203 
204 	/* send PC request commands */
205 	i2c_reg_write(caddr, 0x24, 0x00);
206 	i2c_reg_write(caddr, 0x25, 0x00);
207 	i2c_reg_write(caddr, 0x26, 0x00);
208 
209 	/* native aux read */
210 	i2c_reg_write(caddr, 0x2b, 0x00);
211 	/* back to internal */
212 	i2c_reg_write(caddr, 0x23, 0x40);
213 
214 	/* voltage swing level 3 */
215 	i2c_reg_write(caddr, 0x19, 0xff);
216 	/* pre-emphasis level 3 */
217 	i2c_reg_write(caddr, 0x1a, 0xff);
218 
219 	/* start link training */
220 	i2c_reg_write(caddr, 0x17, 0x01);
221 }
222 
it6251_init(void)223 static int it6251_init(void)
224 {
225 	const unsigned int caddr = NOVENA_IT6251_CHIPADDR;
226 	int reg;
227 	int tries, retries = 0;
228 
229 	for (retries = 0; retries < IT6521_RETRY_MAX; retries++) {
230 		/* Program the chip. */
231 		it6251_program_regs();
232 
233 		/* Wait for video stable. */
234 		for (tries = 0; tries < 100; tries++) {
235 			reg = i2c_reg_read(caddr, 0x17);
236 			/* Test Link CFG, STS, LCS read done. */
237 			if ((reg & 0xe0) != 0xe0) {
238 				/* Not yet, wait a bit more. */
239 				mdelay(2);
240 				continue;
241 			}
242 
243 			/* Test if the video input is stable. */
244 			if (it6251_is_stable())
245 				return 0;
246 		}
247 		/*
248 		 * If we couldn't stabilize, requeue and try again,
249 		 * because it means that the LVDS channel isn't
250 		 * stable yet.
251 		 */
252 		printf("Display didn't stabilize.\n");
253 		printf("This may be because the LVDS port is still in powersave mode.\n");
254 		mdelay(50);
255 	}
256 
257 	return -EINVAL;
258 }
259 
enable_hdmi(struct display_info_t const * dev)260 static void enable_hdmi(struct display_info_t const *dev)
261 {
262 	imx_enable_hdmi_phy();
263 }
264 
265 static int lvds_enabled;
266 
enable_lvds(struct display_info_t const * dev)267 static void enable_lvds(struct display_info_t const *dev)
268 {
269 	if (lvds_enabled)
270 		return;
271 
272 	/* ITE IT6251 power enable. */
273 	gpio_direction_output(NOVENA_ITE6251_PWR_GPIO, 0);
274 	mdelay(10);
275 	gpio_direction_output(NOVENA_ITE6251_PWR_GPIO, 1);
276 	mdelay(20);
277 	lvds_enabled = 1;
278 }
279 
detect_lvds(struct display_info_t const * dev)280 static int detect_lvds(struct display_info_t const *dev)
281 {
282 	int ret, loops = 250;
283 
284 	enable_lvds(dev);
285 
286 	ret = i2c_set_bus_num(NOVENA_IT6251_I2C_BUS);
287 	if (ret) {
288 		puts("Cannot select IT6251 I2C bus.\n");
289 		return 0;
290 	}
291 
292 	/* Wait up-to ~250 mS for the LVDS to come up. */
293 	while (--loops) {
294 		ret = it6251_ready();
295 		if (ret)
296 			return ret;
297 
298 		mdelay(1);
299 	}
300 
301 	return 0;
302 }
303 
304 struct display_info_t const displays[] = {
305 	{
306 		/* HDMI Output */
307 		.bus	= -1,
308 		.addr	= 0,
309 		.pixfmt	= IPU_PIX_FMT_RGB24,
310 		.detect	= detect_hdmi,
311 		.enable	= enable_hdmi,
312 		.mode	= {
313 			.name		= "HDMI",
314 			.refresh	= 60,
315 			.xres		= 1024,
316 			.yres		= 768,
317 			.pixclock	= 15384,
318 			.left_margin	= 220,
319 			.right_margin	= 40,
320 			.upper_margin	= 21,
321 			.lower_margin	= 7,
322 			.hsync_len	= 60,
323 			.vsync_len	= 10,
324 			.sync		= FB_SYNC_EXT,
325 			.vmode		= FB_VMODE_NONINTERLACED
326 		},
327 	}, {
328 		/* LVDS Output: N133HSE-EA1 Rev. C1 */
329 		.bus	= -1,
330 		.pixfmt	= IPU_PIX_FMT_RGB24,
331 		.detect	= detect_lvds,
332 		.enable	= enable_lvds,
333 		.mode	= {
334 			.name		= "Chimei-FHD",
335 			.refresh	= 60,
336 			.xres		= 1920,
337 			.yres		= 1080,
338 			.pixclock	= 15384,
339 			.left_margin	= 148,
340 			.right_margin	= 88,
341 			.upper_margin	= 36,
342 			.lower_margin	= 4,
343 			.hsync_len	= 44,
344 			.vsync_len	= 5,
345 			.sync		= FB_SYNC_HOR_HIGH_ACT |
346 					  FB_SYNC_VERT_HIGH_ACT |
347 					  FB_SYNC_EXT,
348 			.vmode		= FB_VMODE_NONINTERLACED,
349 		},
350 	},
351 };
352 
353 size_t display_count = ARRAY_SIZE(displays);
354 
enable_vpll(void)355 static void enable_vpll(void)
356 {
357 	struct mxc_ccm_reg *ccm = (struct mxc_ccm_reg *)CCM_BASE_ADDR;
358 	int timeout = 100000;
359 
360 	setbits_le32(&ccm->analog_pll_video, BM_ANADIG_PLL_VIDEO_POWERDOWN);
361 
362 	clrsetbits_le32(&ccm->analog_pll_video,
363 			BM_ANADIG_PLL_VIDEO_DIV_SELECT |
364 			BM_ANADIG_PLL_VIDEO_POST_DIV_SELECT,
365 			BF_ANADIG_PLL_VIDEO_DIV_SELECT(37) |
366 			BF_ANADIG_PLL_VIDEO_POST_DIV_SELECT(1));
367 
368 	writel(BF_ANADIG_PLL_VIDEO_NUM_A(11), &ccm->analog_pll_video_num);
369 	writel(BF_ANADIG_PLL_VIDEO_DENOM_B(12), &ccm->analog_pll_video_denom);
370 
371 	clrbits_le32(&ccm->analog_pll_video, BM_ANADIG_PLL_VIDEO_POWERDOWN);
372 
373 	while (timeout--)
374 		if (readl(&ccm->analog_pll_video) & BM_ANADIG_PLL_VIDEO_LOCK)
375 			break;
376 	if (timeout < 0)
377 		printf("Warning: video pll lock timeout!\n");
378 
379 	clrsetbits_le32(&ccm->analog_pll_video,
380 			BM_ANADIG_PLL_VIDEO_BYPASS,
381 			BM_ANADIG_PLL_VIDEO_ENABLE);
382 }
383 
setup_display_clock(void)384 void setup_display_clock(void)
385 {
386 	struct mxc_ccm_reg *mxc_ccm = (struct mxc_ccm_reg *)CCM_BASE_ADDR;
387 	struct iomuxc *iomux = (struct iomuxc *)IOMUXC_BASE_ADDR;
388 
389 	enable_ipu_clock();
390 	enable_vpll();
391 	imx_setup_hdmi();
392 
393 	/* Turn on IPU LDB DI0 clocks */
394 	setbits_le32(&mxc_ccm->CCGR3, MXC_CCM_CCGR3_LDB_DI0_MASK);
395 
396 	/* Switch LDB DI0 to PLL5 (Video PLL) */
397 	clrsetbits_le32(&mxc_ccm->cs2cdr,
398 			MXC_CCM_CS2CDR_LDB_DI0_CLK_SEL_MASK,
399 			(0 << MXC_CCM_CS2CDR_LDB_DI0_CLK_SEL_OFFSET));
400 
401 	/* LDB clock div by 3.5 */
402 	clrbits_le32(&mxc_ccm->cscmr2, MXC_CCM_CSCMR2_LDB_DI0_IPU_DIV);
403 
404 	/* DI0 clock derived from ldb_di0_clk */
405 	clrsetbits_le32(&mxc_ccm->chsccdr,
406 			MXC_CCM_CHSCCDR_IPU1_DI0_CLK_SEL_MASK,
407 			(CHSCCDR_CLK_SEL_LDB_DI0 <<
408 			 MXC_CCM_CHSCCDR_IPU1_DI0_CLK_SEL_OFFSET)
409 			);
410 
411 	/* Enable both LVDS channels, both connected to DI0. */
412 	writel(IOMUXC_GPR2_DI0_VS_POLARITY_ACTIVE_HIGH |
413 	       IOMUXC_GPR2_BIT_MAPPING_CH1_JEIDA |
414 	       IOMUXC_GPR2_DATA_WIDTH_CH1_24BIT |
415 	       IOMUXC_GPR2_BIT_MAPPING_CH0_JEIDA |
416 	       IOMUXC_GPR2_DATA_WIDTH_CH0_24BIT |
417 	       IOMUXC_GPR2_SPLIT_MODE_EN_MASK |
418 	       IOMUXC_GPR2_LVDS_CH1_MODE_ENABLED_DI0 |
419 	       IOMUXC_GPR2_LVDS_CH0_MODE_ENABLED_DI0,
420 	       &iomux->gpr[2]);
421 
422 	clrsetbits_le32(&iomux->gpr[3],
423 			IOMUXC_GPR3_LVDS0_MUX_CTL_MASK |
424 			IOMUXC_GPR3_LVDS1_MUX_CTL_MASK,
425 			(IOMUXC_GPR3_MUX_SRC_IPU1_DI0 <<
426 			 IOMUXC_GPR3_LVDS0_MUX_CTL_OFFSET) |
427 			(IOMUXC_GPR3_MUX_SRC_IPU1_DI0 <<
428 			 IOMUXC_GPR3_LVDS1_MUX_CTL_OFFSET)
429 			);
430 }
431 
setup_display_lvds(void)432 void setup_display_lvds(void)
433 {
434 	int ret;
435 
436 	ret = i2c_set_bus_num(NOVENA_IT6251_I2C_BUS);
437 	if (ret) {
438 		puts("Cannot select LVDS-to-eDP I2C bus.\n");
439 		return;
440 	}
441 
442 	/* The IT6251 should be ready now, if it's not, it's not connected. */
443 	ret = it6251_ready();
444 	if (!ret)
445 		return;
446 
447 	/* Init the LVDS-to-eDP chip and if it succeeded, enable backlight. */
448 	ret = it6251_init();
449 	if (!ret) {
450 		/* Backlight power enable. */
451 		gpio_direction_output(NOVENA_BACKLIGHT_PWR_GPIO, 1);
452 		/* PWM backlight pin, always on for full brightness. */
453 		gpio_direction_output(NOVENA_BACKLIGHT_PWM_GPIO, 1);
454 	}
455 }
456