xref: /linux/drivers/gpu/drm/xlnx/zynqmp_dp.c (revision 0d6ccfe6b319d56da63b7d7cfbcecd92780a680d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ZynqMP DisplayPort Driver
4  *
5  * Copyright (C) 2017 - 2020 Xilinx, Inc.
6  *
7  * Authors:
8  * - Hyun Woo Kwon <hyun.kwon@xilinx.com>
9  * - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
10  */
11 
12 #include <drm/display/drm_dp_helper.h>
13 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_crtc.h>
15 #include <drm/drm_device.h>
16 #include <drm/drm_edid.h>
17 #include <drm/drm_fourcc.h>
18 #include <drm/drm_modes.h>
19 #include <drm/drm_of.h>
20 
21 #include <linux/clk.h>
22 #include <linux/delay.h>
23 #include <linux/device.h>
24 #include <linux/io.h>
25 #include <linux/media-bus-format.h>
26 #include <linux/module.h>
27 #include <linux/platform_device.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/phy/phy.h>
30 #include <linux/reset.h>
31 #include <linux/slab.h>
32 
33 #include "zynqmp_disp.h"
34 #include "zynqmp_dp.h"
35 #include "zynqmp_dpsub.h"
36 #include "zynqmp_kms.h"
37 
38 static uint zynqmp_dp_aux_timeout_ms = 50;
39 module_param_named(aux_timeout_ms, zynqmp_dp_aux_timeout_ms, uint, 0444);
40 MODULE_PARM_DESC(aux_timeout_ms, "DP aux timeout value in msec (default: 50)");
41 
42 /*
43  * Some sink requires a delay after power on request
44  */
45 static uint zynqmp_dp_power_on_delay_ms = 4;
46 module_param_named(power_on_delay_ms, zynqmp_dp_power_on_delay_ms, uint, 0444);
47 MODULE_PARM_DESC(power_on_delay_ms, "DP power on delay in msec (default: 4)");
48 
49 /* Link configuration registers */
50 #define ZYNQMP_DP_LINK_BW_SET				0x0
51 #define ZYNQMP_DP_LANE_COUNT_SET			0x4
52 #define ZYNQMP_DP_ENHANCED_FRAME_EN			0x8
53 #define ZYNQMP_DP_TRAINING_PATTERN_SET			0xc
54 #define ZYNQMP_DP_SCRAMBLING_DISABLE			0x14
55 #define ZYNQMP_DP_DOWNSPREAD_CTL			0x18
56 #define ZYNQMP_DP_SOFTWARE_RESET			0x1c
57 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM1		BIT(0)
58 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM2		BIT(1)
59 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM3		BIT(2)
60 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM4		BIT(3)
61 #define ZYNQMP_DP_SOFTWARE_RESET_AUX			BIT(7)
62 #define ZYNQMP_DP_SOFTWARE_RESET_ALL			(ZYNQMP_DP_SOFTWARE_RESET_STREAM1 | \
63 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM2 | \
64 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM3 | \
65 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM4 | \
66 							 ZYNQMP_DP_SOFTWARE_RESET_AUX)
67 
68 /* Core enable registers */
69 #define ZYNQMP_DP_TRANSMITTER_ENABLE			0x80
70 #define ZYNQMP_DP_MAIN_STREAM_ENABLE			0x84
71 #define ZYNQMP_DP_FORCE_SCRAMBLER_RESET			0xc0
72 #define ZYNQMP_DP_VERSION				0xf8
73 #define ZYNQMP_DP_VERSION_MAJOR_MASK			GENMASK(31, 24)
74 #define ZYNQMP_DP_VERSION_MAJOR_SHIFT			24
75 #define ZYNQMP_DP_VERSION_MINOR_MASK			GENMASK(23, 16)
76 #define ZYNQMP_DP_VERSION_MINOR_SHIFT			16
77 #define ZYNQMP_DP_VERSION_REVISION_MASK			GENMASK(15, 12)
78 #define ZYNQMP_DP_VERSION_REVISION_SHIFT		12
79 #define ZYNQMP_DP_VERSION_PATCH_MASK			GENMASK(11, 8)
80 #define ZYNQMP_DP_VERSION_PATCH_SHIFT			8
81 #define ZYNQMP_DP_VERSION_INTERNAL_MASK			GENMASK(7, 0)
82 #define ZYNQMP_DP_VERSION_INTERNAL_SHIFT		0
83 
84 /* Core ID registers */
85 #define ZYNQMP_DP_CORE_ID				0xfc
86 #define ZYNQMP_DP_CORE_ID_MAJOR_MASK			GENMASK(31, 24)
87 #define ZYNQMP_DP_CORE_ID_MAJOR_SHIFT			24
88 #define ZYNQMP_DP_CORE_ID_MINOR_MASK			GENMASK(23, 16)
89 #define ZYNQMP_DP_CORE_ID_MINOR_SHIFT			16
90 #define ZYNQMP_DP_CORE_ID_REVISION_MASK			GENMASK(15, 8)
91 #define ZYNQMP_DP_CORE_ID_REVISION_SHIFT		8
92 #define ZYNQMP_DP_CORE_ID_DIRECTION			GENMASK(1)
93 
94 /* AUX channel interface registers */
95 #define ZYNQMP_DP_AUX_COMMAND				0x100
96 #define ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT			8
97 #define ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY		BIT(12)
98 #define ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT		0
99 #define ZYNQMP_DP_AUX_WRITE_FIFO			0x104
100 #define ZYNQMP_DP_AUX_ADDRESS				0x108
101 #define ZYNQMP_DP_AUX_CLK_DIVIDER			0x10c
102 #define ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT	8
103 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE		0x130
104 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD		BIT(0)
105 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST	BIT(1)
106 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY		BIT(2)
107 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT	BIT(3)
108 #define ZYNQMP_DP_AUX_REPLY_DATA			0x134
109 #define ZYNQMP_DP_AUX_REPLY_CODE			0x138
110 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK		(0)
111 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_NACK		BIT(0)
112 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_DEFER		BIT(1)
113 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK		(0)
114 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_NACK		BIT(2)
115 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_DEFER		BIT(3)
116 #define ZYNQMP_DP_AUX_REPLY_COUNT			0x13c
117 #define ZYNQMP_DP_REPLY_DATA_COUNT			0x148
118 #define ZYNQMP_DP_REPLY_DATA_COUNT_MASK			0xff
119 #define ZYNQMP_DP_INT_STATUS				0x3a0
120 #define ZYNQMP_DP_INT_MASK				0x3a4
121 #define ZYNQMP_DP_INT_EN				0x3a8
122 #define ZYNQMP_DP_INT_DS				0x3ac
123 #define ZYNQMP_DP_INT_HPD_IRQ				BIT(0)
124 #define ZYNQMP_DP_INT_HPD_EVENT				BIT(1)
125 #define ZYNQMP_DP_INT_REPLY_RECEIVED			BIT(2)
126 #define ZYNQMP_DP_INT_REPLY_TIMEOUT			BIT(3)
127 #define ZYNQMP_DP_INT_HPD_PULSE_DET			BIT(4)
128 #define ZYNQMP_DP_INT_EXT_PKT_TXD			BIT(5)
129 #define ZYNQMP_DP_INT_LIV_ABUF_UNDRFLW			BIT(12)
130 #define ZYNQMP_DP_INT_VBLANK_START			BIT(13)
131 #define ZYNQMP_DP_INT_PIXEL1_MATCH			BIT(14)
132 #define ZYNQMP_DP_INT_PIXEL0_MATCH			BIT(15)
133 #define ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK		0x3f0000
134 #define ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK		0xfc00000
135 #define ZYNQMP_DP_INT_CUST_TS_2				BIT(28)
136 #define ZYNQMP_DP_INT_CUST_TS				BIT(29)
137 #define ZYNQMP_DP_INT_EXT_VSYNC_TS			BIT(30)
138 #define ZYNQMP_DP_INT_VSYNC_TS				BIT(31)
139 #define ZYNQMP_DP_INT_ALL				(ZYNQMP_DP_INT_HPD_IRQ | \
140 							 ZYNQMP_DP_INT_HPD_EVENT | \
141 							 ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK | \
142 							 ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
143 
144 /* Main stream attribute registers */
145 #define ZYNQMP_DP_MAIN_STREAM_HTOTAL			0x180
146 #define ZYNQMP_DP_MAIN_STREAM_VTOTAL			0x184
147 #define ZYNQMP_DP_MAIN_STREAM_POLARITY			0x188
148 #define ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT	0
149 #define ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT	1
150 #define ZYNQMP_DP_MAIN_STREAM_HSWIDTH			0x18c
151 #define ZYNQMP_DP_MAIN_STREAM_VSWIDTH			0x190
152 #define ZYNQMP_DP_MAIN_STREAM_HRES			0x194
153 #define ZYNQMP_DP_MAIN_STREAM_VRES			0x198
154 #define ZYNQMP_DP_MAIN_STREAM_HSTART			0x19c
155 #define ZYNQMP_DP_MAIN_STREAM_VSTART			0x1a0
156 #define ZYNQMP_DP_MAIN_STREAM_MISC0			0x1a4
157 #define ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK		BIT(0)
158 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB	(0 << 1)
159 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422	(5 << 1)
160 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444	(6 << 1)
161 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK	(7 << 1)
162 #define ZYNQMP_DP_MAIN_STREAM_MISC0_DYNAMIC_RANGE	BIT(3)
163 #define ZYNQMP_DP_MAIN_STREAM_MISC0_YCBCR_COLR		BIT(4)
164 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6		(0 << 5)
165 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8		(1 << 5)
166 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10		(2 << 5)
167 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12		(3 << 5)
168 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16		(4 << 5)
169 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK		(7 << 5)
170 #define ZYNQMP_DP_MAIN_STREAM_MISC1			0x1a8
171 #define ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN		BIT(7)
172 #define ZYNQMP_DP_MAIN_STREAM_M_VID			0x1ac
173 #define ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE		0x1b0
174 #define ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF	64
175 #define ZYNQMP_DP_MAIN_STREAM_N_VID			0x1b4
176 #define ZYNQMP_DP_USER_PIX_WIDTH			0x1b8
177 #define ZYNQMP_DP_USER_DATA_COUNT_PER_LANE		0x1bc
178 #define ZYNQMP_DP_MIN_BYTES_PER_TU			0x1c4
179 #define ZYNQMP_DP_FRAC_BYTES_PER_TU			0x1c8
180 #define ZYNQMP_DP_INIT_WAIT				0x1cc
181 
182 /* PHY configuration and status registers */
183 #define ZYNQMP_DP_PHY_RESET				0x200
184 #define ZYNQMP_DP_PHY_RESET_PHY_RESET			BIT(0)
185 #define ZYNQMP_DP_PHY_RESET_GTTX_RESET			BIT(1)
186 #define ZYNQMP_DP_PHY_RESET_PHY_PMA_RESET		BIT(8)
187 #define ZYNQMP_DP_PHY_RESET_PHY_PCS_RESET		BIT(9)
188 #define ZYNQMP_DP_PHY_RESET_ALL_RESET			(ZYNQMP_DP_PHY_RESET_PHY_RESET | \
189 							 ZYNQMP_DP_PHY_RESET_GTTX_RESET | \
190 							 ZYNQMP_DP_PHY_RESET_PHY_PMA_RESET | \
191 							 ZYNQMP_DP_PHY_RESET_PHY_PCS_RESET)
192 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_0		0x210
193 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_1		0x214
194 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_2		0x218
195 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_3		0x21c
196 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_0		0x220
197 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_1		0x224
198 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_2		0x228
199 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_3		0x22c
200 #define ZYNQMP_DP_PHY_CLOCK_SELECT			0x234
201 #define ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G		0x1
202 #define ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G		0x3
203 #define ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G		0x5
204 #define ZYNQMP_DP_TX_PHY_POWER_DOWN			0x238
205 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_0		BIT(0)
206 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_1		BIT(1)
207 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_2		BIT(2)
208 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_3		BIT(3)
209 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL			0xf
210 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_0			0x23c
211 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_1			0x240
212 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_2			0x244
213 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_3			0x248
214 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_0			0x24c
215 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_1			0x250
216 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_2			0x254
217 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_3			0x258
218 #define ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0		0x24c
219 #define ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_1		0x250
220 #define ZYNQMP_DP_PHY_STATUS				0x280
221 #define ZYNQMP_DP_PHY_STATUS_PLL_LOCKED_SHIFT		4
222 #define ZYNQMP_DP_PHY_STATUS_FPGA_PLL_LOCKED		BIT(6)
223 
224 /* Audio registers */
225 #define ZYNQMP_DP_TX_AUDIO_CONTROL			0x300
226 #define ZYNQMP_DP_TX_AUDIO_CHANNELS			0x304
227 #define ZYNQMP_DP_TX_AUDIO_INFO_DATA			0x308
228 #define ZYNQMP_DP_TX_M_AUD				0x328
229 #define ZYNQMP_DP_TX_N_AUD				0x32c
230 #define ZYNQMP_DP_TX_AUDIO_EXT_DATA			0x330
231 
232 #define ZYNQMP_DP_MAX_LANES				2
233 #define ZYNQMP_MAX_FREQ					3000000
234 
235 #define DP_REDUCED_BIT_RATE				162000
236 #define DP_HIGH_BIT_RATE				270000
237 #define DP_HIGH_BIT_RATE2				540000
238 #define DP_MAX_TRAINING_TRIES				5
239 #define DP_V1_2						0x12
240 
241 /**
242  * struct zynqmp_dp_link_config - Common link config between source and sink
243  * @max_rate: maximum link rate
244  * @max_lanes: maximum number of lanes
245  */
246 struct zynqmp_dp_link_config {
247 	int max_rate;
248 	u8 max_lanes;
249 };
250 
251 /**
252  * struct zynqmp_dp_mode - Configured mode of DisplayPort
253  * @bw_code: code for bandwidth(link rate)
254  * @lane_cnt: number of lanes
255  * @pclock: pixel clock frequency of current mode
256  * @fmt: format identifier string
257  */
258 struct zynqmp_dp_mode {
259 	const char *fmt;
260 	int pclock;
261 	u8 bw_code;
262 	u8 lane_cnt;
263 };
264 
265 /**
266  * struct zynqmp_dp_config - Configuration of DisplayPort from DTS
267  * @misc0: misc0 configuration (per DP v1.2 spec)
268  * @misc1: misc1 configuration (per DP v1.2 spec)
269  * @bpp: bits per pixel
270  */
271 struct zynqmp_dp_config {
272 	u8 misc0;
273 	u8 misc1;
274 	u8 bpp;
275 };
276 
277 /**
278  * struct zynqmp_dp - Xilinx DisplayPort core
279  * @dev: device structure
280  * @dpsub: Display subsystem
281  * @iomem: device I/O memory for register access
282  * @reset: reset controller
283  * @irq: irq
284  * @bridge: DRM bridge for the DP encoder
285  * @next_bridge: The downstream bridge
286  * @config: IP core configuration from DTS
287  * @aux: aux channel
288  * @phy: PHY handles for DP lanes
289  * @num_lanes: number of enabled phy lanes
290  * @hpd_work: hot plug detection worker
291  * @status: connection status
292  * @enabled: flag to indicate if the device is enabled
293  * @dpcd: DP configuration data from currently connected sink device
294  * @link_config: common link configuration between IP core and sink device
295  * @mode: current mode between IP core and sink device
296  * @train_set: set of training data
297  */
298 struct zynqmp_dp {
299 	struct drm_dp_aux aux;
300 	struct drm_bridge bridge;
301 	struct work_struct hpd_work;
302 
303 	struct drm_bridge *next_bridge;
304 	struct device *dev;
305 	struct zynqmp_dpsub *dpsub;
306 	void __iomem *iomem;
307 	struct reset_control *reset;
308 	struct phy *phy[ZYNQMP_DP_MAX_LANES];
309 
310 	enum drm_connector_status status;
311 	int irq;
312 	bool enabled;
313 
314 	struct zynqmp_dp_mode mode;
315 	struct zynqmp_dp_link_config link_config;
316 	struct zynqmp_dp_config config;
317 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
318 	u8 train_set[ZYNQMP_DP_MAX_LANES];
319 	u8 num_lanes;
320 };
321 
322 static inline struct zynqmp_dp *bridge_to_dp(struct drm_bridge *bridge)
323 {
324 	return container_of(bridge, struct zynqmp_dp, bridge);
325 }
326 
327 static void zynqmp_dp_write(struct zynqmp_dp *dp, int offset, u32 val)
328 {
329 	writel(val, dp->iomem + offset);
330 }
331 
332 static u32 zynqmp_dp_read(struct zynqmp_dp *dp, int offset)
333 {
334 	return readl(dp->iomem + offset);
335 }
336 
337 static void zynqmp_dp_clr(struct zynqmp_dp *dp, int offset, u32 clr)
338 {
339 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) & ~clr);
340 }
341 
342 static void zynqmp_dp_set(struct zynqmp_dp *dp, int offset, u32 set)
343 {
344 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) | set);
345 }
346 
347 /* -----------------------------------------------------------------------------
348  * PHY Handling
349  */
350 
351 #define RST_TIMEOUT_MS			1000
352 
353 static int zynqmp_dp_reset(struct zynqmp_dp *dp, bool assert)
354 {
355 	unsigned long timeout;
356 
357 	if (assert)
358 		reset_control_assert(dp->reset);
359 	else
360 		reset_control_deassert(dp->reset);
361 
362 	/* Wait for the (de)assert to complete. */
363 	timeout = jiffies + msecs_to_jiffies(RST_TIMEOUT_MS);
364 	while (!time_after_eq(jiffies, timeout)) {
365 		bool status = !!reset_control_status(dp->reset);
366 
367 		if (assert == status)
368 			return 0;
369 
370 		cpu_relax();
371 	}
372 
373 	dev_err(dp->dev, "reset %s timeout\n", assert ? "assert" : "deassert");
374 	return -ETIMEDOUT;
375 }
376 
377 /**
378  * zynqmp_dp_phy_init - Initialize the phy
379  * @dp: DisplayPort IP core structure
380  *
381  * Initialize the phy.
382  *
383  * Return: 0 if the phy instances are initialized correctly, or the error code
384  * returned from the callee functions.
385  */
386 static int zynqmp_dp_phy_init(struct zynqmp_dp *dp)
387 {
388 	int ret;
389 	int i;
390 
391 	for (i = 0; i < dp->num_lanes; i++) {
392 		ret = phy_init(dp->phy[i]);
393 		if (ret) {
394 			dev_err(dp->dev, "failed to init phy lane %d\n", i);
395 			return ret;
396 		}
397 	}
398 
399 	zynqmp_dp_clr(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
400 
401 	/*
402 	 * Power on lanes in reverse order as only lane 0 waits for the PLL to
403 	 * lock.
404 	 */
405 	for (i = dp->num_lanes - 1; i >= 0; i--) {
406 		ret = phy_power_on(dp->phy[i]);
407 		if (ret) {
408 			dev_err(dp->dev, "failed to power on phy lane %d\n", i);
409 			return ret;
410 		}
411 	}
412 
413 	return 0;
414 }
415 
416 /**
417  * zynqmp_dp_phy_exit - Exit the phy
418  * @dp: DisplayPort IP core structure
419  *
420  * Exit the phy.
421  */
422 static void zynqmp_dp_phy_exit(struct zynqmp_dp *dp)
423 {
424 	unsigned int i;
425 	int ret;
426 
427 	for (i = 0; i < dp->num_lanes; i++) {
428 		ret = phy_power_off(dp->phy[i]);
429 		if (ret)
430 			dev_err(dp->dev, "failed to power off phy(%d) %d\n", i,
431 				ret);
432 	}
433 
434 	for (i = 0; i < dp->num_lanes; i++) {
435 		ret = phy_exit(dp->phy[i]);
436 		if (ret)
437 			dev_err(dp->dev, "failed to exit phy(%d) %d\n", i, ret);
438 	}
439 }
440 
441 /**
442  * zynqmp_dp_phy_probe - Probe the PHYs
443  * @dp: DisplayPort IP core structure
444  *
445  * Probe PHYs for all lanes. Less PHYs may be available than the number of
446  * lanes, which is not considered an error as long as at least one PHY is
447  * found. The caller can check dp->num_lanes to check how many PHYs were found.
448  *
449  * Return:
450  * * 0				- Success
451  * * -ENXIO			- No PHY found
452  * * -EPROBE_DEFER		- Probe deferral requested
453  * * Other negative value	- PHY retrieval failure
454  */
455 static int zynqmp_dp_phy_probe(struct zynqmp_dp *dp)
456 {
457 	unsigned int i;
458 
459 	for (i = 0; i < ZYNQMP_DP_MAX_LANES; i++) {
460 		char phy_name[16];
461 		struct phy *phy;
462 
463 		snprintf(phy_name, sizeof(phy_name), "dp-phy%d", i);
464 		phy = devm_phy_get(dp->dev, phy_name);
465 
466 		if (IS_ERR(phy)) {
467 			switch (PTR_ERR(phy)) {
468 			case -ENODEV:
469 				if (dp->num_lanes)
470 					return 0;
471 
472 				dev_err(dp->dev, "no PHY found\n");
473 				return -ENXIO;
474 
475 			case -EPROBE_DEFER:
476 				return -EPROBE_DEFER;
477 
478 			default:
479 				dev_err(dp->dev, "failed to get PHY lane %u\n",
480 					i);
481 				return PTR_ERR(phy);
482 			}
483 		}
484 
485 		dp->phy[i] = phy;
486 		dp->num_lanes++;
487 	}
488 
489 	return 0;
490 }
491 
492 /**
493  * zynqmp_dp_phy_ready - Check if PHY is ready
494  * @dp: DisplayPort IP core structure
495  *
496  * Check if PHY is ready. If PHY is not ready, wait 1ms to check for 100 times.
497  * This amount of delay was suggested by IP designer.
498  *
499  * Return: 0 if PHY is ready, or -ENODEV if PHY is not ready.
500  */
501 static int zynqmp_dp_phy_ready(struct zynqmp_dp *dp)
502 {
503 	u32 i, reg, ready;
504 
505 	ready = (1 << dp->num_lanes) - 1;
506 
507 	/* Wait for 100 * 1ms. This should be enough time for PHY to be ready */
508 	for (i = 0; ; i++) {
509 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_PHY_STATUS);
510 		if ((reg & ready) == ready)
511 			return 0;
512 
513 		if (i == 100) {
514 			dev_err(dp->dev, "PHY isn't ready\n");
515 			return -ENODEV;
516 		}
517 
518 		usleep_range(1000, 1100);
519 	}
520 
521 	return 0;
522 }
523 
524 /* -----------------------------------------------------------------------------
525  * DisplayPort Link Training
526  */
527 
528 /**
529  * zynqmp_dp_max_rate - Calculate and return available max pixel clock
530  * @link_rate: link rate (Kilo-bytes / sec)
531  * @lane_num: number of lanes
532  * @bpp: bits per pixel
533  *
534  * Return: max pixel clock (KHz) supported by current link config.
535  */
536 static inline int zynqmp_dp_max_rate(int link_rate, u8 lane_num, u8 bpp)
537 {
538 	return link_rate * lane_num * 8 / bpp;
539 }
540 
541 /**
542  * zynqmp_dp_mode_configure - Configure the link values
543  * @dp: DisplayPort IP core structure
544  * @pclock: pixel clock for requested display mode
545  * @current_bw: current link rate
546  *
547  * Find the link configuration values, rate and lane count for requested pixel
548  * clock @pclock. The @pclock is stored in the mode to be used in other
549  * functions later. The returned rate is downshifted from the current rate
550  * @current_bw.
551  *
552  * Return: Current link rate code, or -EINVAL.
553  */
554 static int zynqmp_dp_mode_configure(struct zynqmp_dp *dp, int pclock,
555 				    u8 current_bw)
556 {
557 	int max_rate = dp->link_config.max_rate;
558 	u8 bw_code;
559 	u8 max_lanes = dp->link_config.max_lanes;
560 	u8 max_link_rate_code = drm_dp_link_rate_to_bw_code(max_rate);
561 	u8 bpp = dp->config.bpp;
562 	u8 lane_cnt;
563 
564 	/* Downshift from current bandwidth */
565 	switch (current_bw) {
566 	case DP_LINK_BW_5_4:
567 		bw_code = DP_LINK_BW_2_7;
568 		break;
569 	case DP_LINK_BW_2_7:
570 		bw_code = DP_LINK_BW_1_62;
571 		break;
572 	case DP_LINK_BW_1_62:
573 		dev_err(dp->dev, "can't downshift. already lowest link rate\n");
574 		return -EINVAL;
575 	default:
576 		/* If not given, start with max supported */
577 		bw_code = max_link_rate_code;
578 		break;
579 	}
580 
581 	for (lane_cnt = 1; lane_cnt <= max_lanes; lane_cnt <<= 1) {
582 		int bw;
583 		u32 rate;
584 
585 		bw = drm_dp_bw_code_to_link_rate(bw_code);
586 		rate = zynqmp_dp_max_rate(bw, lane_cnt, bpp);
587 		if (pclock <= rate) {
588 			dp->mode.bw_code = bw_code;
589 			dp->mode.lane_cnt = lane_cnt;
590 			dp->mode.pclock = pclock;
591 			return dp->mode.bw_code;
592 		}
593 	}
594 
595 	dev_err(dp->dev, "failed to configure link values\n");
596 
597 	return -EINVAL;
598 }
599 
600 /**
601  * zynqmp_dp_adjust_train - Adjust train values
602  * @dp: DisplayPort IP core structure
603  * @link_status: link status from sink which contains requested training values
604  */
605 static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp,
606 				   u8 link_status[DP_LINK_STATUS_SIZE])
607 {
608 	u8 *train_set = dp->train_set;
609 	u8 i;
610 
611 	for (i = 0; i < dp->mode.lane_cnt; i++) {
612 		u8 voltage = drm_dp_get_adjust_request_voltage(link_status, i);
613 		u8 preemphasis =
614 			drm_dp_get_adjust_request_pre_emphasis(link_status, i);
615 
616 		if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3)
617 			voltage |= DP_TRAIN_MAX_SWING_REACHED;
618 
619 		if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2)
620 			preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
621 
622 		train_set[i] = voltage | preemphasis;
623 	}
624 }
625 
626 /**
627  * zynqmp_dp_update_vs_emph - Update the training values
628  * @dp: DisplayPort IP core structure
629  *
630  * Update the training values based on the request from sink. The mapped values
631  * are predefined, and values(vs, pe, pc) are from the device manual.
632  *
633  * Return: 0 if vs and emph are updated successfully, or the error code returned
634  * by drm_dp_dpcd_write().
635  */
636 static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
637 {
638 	unsigned int i;
639 	int ret;
640 
641 	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->train_set,
642 				dp->mode.lane_cnt);
643 	if (ret < 0)
644 		return ret;
645 
646 	for (i = 0; i < dp->mode.lane_cnt; i++) {
647 		u32 reg = ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0 + i * 4;
648 		union phy_configure_opts opts = { 0 };
649 		u8 train = dp->train_set[i];
650 
651 		opts.dp.voltage[0] = (train & DP_TRAIN_VOLTAGE_SWING_MASK)
652 				   >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
653 		opts.dp.pre[0] = (train & DP_TRAIN_PRE_EMPHASIS_MASK)
654 			       >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
655 
656 		phy_configure(dp->phy[i], &opts);
657 
658 		zynqmp_dp_write(dp, reg, 0x2);
659 	}
660 
661 	return 0;
662 }
663 
664 /**
665  * zynqmp_dp_link_train_cr - Train clock recovery
666  * @dp: DisplayPort IP core structure
667  *
668  * Return: 0 if clock recovery train is done successfully, or corresponding
669  * error code.
670  */
671 static int zynqmp_dp_link_train_cr(struct zynqmp_dp *dp)
672 {
673 	u8 link_status[DP_LINK_STATUS_SIZE];
674 	u8 lane_cnt = dp->mode.lane_cnt;
675 	u8 vs = 0, tries = 0;
676 	u16 max_tries, i;
677 	bool cr_done;
678 	int ret;
679 
680 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
681 			DP_TRAINING_PATTERN_1);
682 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
683 				 DP_TRAINING_PATTERN_1 |
684 				 DP_LINK_SCRAMBLING_DISABLE);
685 	if (ret < 0)
686 		return ret;
687 
688 	/*
689 	 * 256 loops should be maximum iterations for 4 lanes and 4 values.
690 	 * So, This loop should exit before 512 iterations
691 	 */
692 	for (max_tries = 0; max_tries < 512; max_tries++) {
693 		ret = zynqmp_dp_update_vs_emph(dp);
694 		if (ret)
695 			return ret;
696 
697 		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
698 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
699 		if (ret < 0)
700 			return ret;
701 
702 		cr_done = drm_dp_clock_recovery_ok(link_status, lane_cnt);
703 		if (cr_done)
704 			break;
705 
706 		for (i = 0; i < lane_cnt; i++)
707 			if (!(dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED))
708 				break;
709 		if (i == lane_cnt)
710 			break;
711 
712 		if ((dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == vs)
713 			tries++;
714 		else
715 			tries = 0;
716 
717 		if (tries == DP_MAX_TRAINING_TRIES)
718 			break;
719 
720 		vs = dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
721 		zynqmp_dp_adjust_train(dp, link_status);
722 	}
723 
724 	if (!cr_done)
725 		return -EIO;
726 
727 	return 0;
728 }
729 
730 /**
731  * zynqmp_dp_link_train_ce - Train channel equalization
732  * @dp: DisplayPort IP core structure
733  *
734  * Return: 0 if channel equalization train is done successfully, or
735  * corresponding error code.
736  */
737 static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
738 {
739 	u8 link_status[DP_LINK_STATUS_SIZE];
740 	u8 lane_cnt = dp->mode.lane_cnt;
741 	u32 pat, tries;
742 	int ret;
743 	bool ce_done;
744 
745 	if (dp->dpcd[DP_DPCD_REV] >= DP_V1_2 &&
746 	    dp->dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED)
747 		pat = DP_TRAINING_PATTERN_3;
748 	else
749 		pat = DP_TRAINING_PATTERN_2;
750 
751 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET, pat);
752 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
753 				 pat | DP_LINK_SCRAMBLING_DISABLE);
754 	if (ret < 0)
755 		return ret;
756 
757 	for (tries = 0; tries < DP_MAX_TRAINING_TRIES; tries++) {
758 		ret = zynqmp_dp_update_vs_emph(dp);
759 		if (ret)
760 			return ret;
761 
762 		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
763 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
764 		if (ret < 0)
765 			return ret;
766 
767 		ce_done = drm_dp_channel_eq_ok(link_status, lane_cnt);
768 		if (ce_done)
769 			break;
770 
771 		zynqmp_dp_adjust_train(dp, link_status);
772 	}
773 
774 	if (!ce_done)
775 		return -EIO;
776 
777 	return 0;
778 }
779 
780 /**
781  * zynqmp_dp_train - Train the link
782  * @dp: DisplayPort IP core structure
783  *
784  * Return: 0 if all trains are done successfully, or corresponding error code.
785  */
786 static int zynqmp_dp_train(struct zynqmp_dp *dp)
787 {
788 	u32 reg;
789 	u8 bw_code = dp->mode.bw_code;
790 	u8 lane_cnt = dp->mode.lane_cnt;
791 	u8 aux_lane_cnt = lane_cnt;
792 	bool enhanced;
793 	int ret;
794 
795 	zynqmp_dp_write(dp, ZYNQMP_DP_LANE_COUNT_SET, lane_cnt);
796 	enhanced = drm_dp_enhanced_frame_cap(dp->dpcd);
797 	if (enhanced) {
798 		zynqmp_dp_write(dp, ZYNQMP_DP_ENHANCED_FRAME_EN, 1);
799 		aux_lane_cnt |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
800 	}
801 
802 	if (dp->dpcd[3] & 0x1) {
803 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 1);
804 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL,
805 				   DP_SPREAD_AMP_0_5);
806 	} else {
807 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 0);
808 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL, 0);
809 	}
810 
811 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET, aux_lane_cnt);
812 	if (ret < 0) {
813 		dev_err(dp->dev, "failed to set lane count\n");
814 		return ret;
815 	}
816 
817 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
818 				 DP_SET_ANSI_8B10B);
819 	if (ret < 0) {
820 		dev_err(dp->dev, "failed to set ANSI 8B/10B encoding\n");
821 		return ret;
822 	}
823 
824 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LINK_BW_SET, bw_code);
825 	if (ret < 0) {
826 		dev_err(dp->dev, "failed to set DP bandwidth\n");
827 		return ret;
828 	}
829 
830 	zynqmp_dp_write(dp, ZYNQMP_DP_LINK_BW_SET, bw_code);
831 	switch (bw_code) {
832 	case DP_LINK_BW_1_62:
833 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G;
834 		break;
835 	case DP_LINK_BW_2_7:
836 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G;
837 		break;
838 	case DP_LINK_BW_5_4:
839 	default:
840 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G;
841 		break;
842 	}
843 
844 	zynqmp_dp_write(dp, ZYNQMP_DP_PHY_CLOCK_SELECT, reg);
845 	ret = zynqmp_dp_phy_ready(dp);
846 	if (ret < 0)
847 		return ret;
848 
849 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 1);
850 	memset(dp->train_set, 0, sizeof(dp->train_set));
851 	ret = zynqmp_dp_link_train_cr(dp);
852 	if (ret)
853 		return ret;
854 
855 	ret = zynqmp_dp_link_train_ce(dp);
856 	if (ret)
857 		return ret;
858 
859 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
860 				 DP_TRAINING_PATTERN_DISABLE);
861 	if (ret < 0) {
862 		dev_err(dp->dev, "failed to disable training pattern\n");
863 		return ret;
864 	}
865 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
866 			DP_TRAINING_PATTERN_DISABLE);
867 
868 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 0);
869 
870 	return 0;
871 }
872 
873 /**
874  * zynqmp_dp_train_loop - Downshift the link rate during training
875  * @dp: DisplayPort IP core structure
876  *
877  * Train the link by downshifting the link rate if training is not successful.
878  */
879 static void zynqmp_dp_train_loop(struct zynqmp_dp *dp)
880 {
881 	struct zynqmp_dp_mode *mode = &dp->mode;
882 	u8 bw = mode->bw_code;
883 	int ret;
884 
885 	do {
886 		if (dp->status == connector_status_disconnected ||
887 		    !dp->enabled)
888 			return;
889 
890 		ret = zynqmp_dp_train(dp);
891 		if (!ret)
892 			return;
893 
894 		ret = zynqmp_dp_mode_configure(dp, mode->pclock, bw);
895 		if (ret < 0)
896 			goto err_out;
897 
898 		bw = ret;
899 	} while (bw >= DP_LINK_BW_1_62);
900 
901 err_out:
902 	dev_err(dp->dev, "failed to train the DP link\n");
903 }
904 
905 /* -----------------------------------------------------------------------------
906  * DisplayPort AUX
907  */
908 
909 #define AUX_READ_BIT	0x1
910 
911 /**
912  * zynqmp_dp_aux_cmd_submit - Submit aux command
913  * @dp: DisplayPort IP core structure
914  * @cmd: aux command
915  * @addr: aux address
916  * @buf: buffer for command data
917  * @bytes: number of bytes for @buf
918  * @reply: reply code to be returned
919  *
920  * Submit an aux command. All aux related commands, native or i2c aux
921  * read/write, are submitted through this function. The function is mapped to
922  * the transfer function of struct drm_dp_aux. This function involves in
923  * multiple register reads/writes, thus synchronization is needed, and it is
924  * done by drm_dp_helper using @hw_mutex. The calling thread goes into sleep
925  * if there's no immediate reply to the command submission. The reply code is
926  * returned at @reply if @reply != NULL.
927  *
928  * Return: 0 if the command is submitted properly, or corresponding error code:
929  * -EBUSY when there is any request already being processed
930  * -ETIMEDOUT when receiving reply is timed out
931  * -EIO when received bytes are less than requested
932  */
933 static int zynqmp_dp_aux_cmd_submit(struct zynqmp_dp *dp, u32 cmd, u16 addr,
934 				    u8 *buf, u8 bytes, u8 *reply)
935 {
936 	bool is_read = (cmd & AUX_READ_BIT) ? true : false;
937 	u32 reg, i;
938 
939 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
940 	if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST)
941 		return -EBUSY;
942 
943 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_ADDRESS, addr);
944 	if (!is_read)
945 		for (i = 0; i < bytes; i++)
946 			zynqmp_dp_write(dp, ZYNQMP_DP_AUX_WRITE_FIFO,
947 					buf[i]);
948 
949 	reg = cmd << ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT;
950 	if (!buf || !bytes)
951 		reg |= ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY;
952 	else
953 		reg |= (bytes - 1) << ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT;
954 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_COMMAND, reg);
955 
956 	/* Wait for reply to be delivered upto 2ms */
957 	for (i = 0; ; i++) {
958 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
959 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY)
960 			break;
961 
962 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT ||
963 		    i == 2)
964 			return -ETIMEDOUT;
965 
966 		usleep_range(1000, 1100);
967 	}
968 
969 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_CODE);
970 	if (reply)
971 		*reply = reg;
972 
973 	if (is_read &&
974 	    (reg == ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK ||
975 	     reg == ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK)) {
976 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_REPLY_DATA_COUNT);
977 		if ((reg & ZYNQMP_DP_REPLY_DATA_COUNT_MASK) != bytes)
978 			return -EIO;
979 
980 		for (i = 0; i < bytes; i++)
981 			buf[i] = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_DATA);
982 	}
983 
984 	return 0;
985 }
986 
987 static ssize_t
988 zynqmp_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
989 {
990 	struct zynqmp_dp *dp = container_of(aux, struct zynqmp_dp, aux);
991 	int ret;
992 	unsigned int i, iter;
993 
994 	/* Number of loops = timeout in msec / aux delay (400 usec) */
995 	iter = zynqmp_dp_aux_timeout_ms * 1000 / 400;
996 	iter = iter ? iter : 1;
997 
998 	for (i = 0; i < iter; i++) {
999 		ret = zynqmp_dp_aux_cmd_submit(dp, msg->request, msg->address,
1000 					       msg->buffer, msg->size,
1001 					       &msg->reply);
1002 		if (!ret) {
1003 			dev_vdbg(dp->dev, "aux %d retries\n", i);
1004 			return msg->size;
1005 		}
1006 
1007 		if (dp->status == connector_status_disconnected) {
1008 			dev_dbg(dp->dev, "no connected aux device\n");
1009 			return -ENODEV;
1010 		}
1011 
1012 		usleep_range(400, 500);
1013 	}
1014 
1015 	dev_dbg(dp->dev, "failed to do aux transfer (%d)\n", ret);
1016 
1017 	return ret;
1018 }
1019 
1020 /**
1021  * zynqmp_dp_aux_init - Initialize and register the DP AUX
1022  * @dp: DisplayPort IP core structure
1023  *
1024  * Program the AUX clock divider and filter and register the DP AUX adapter.
1025  *
1026  * Return: 0 on success, error value otherwise
1027  */
1028 static int zynqmp_dp_aux_init(struct zynqmp_dp *dp)
1029 {
1030 	unsigned long rate;
1031 	unsigned int w;
1032 
1033 	/*
1034 	 * The AUX_SIGNAL_WIDTH_FILTER is the number of APB clock cycles
1035 	 * corresponding to the AUX pulse. Allowable values are 8, 16, 24, 32,
1036 	 * 40 and 48. The AUX pulse width must be between 0.4µs and 0.6µs,
1037 	 * compute the w / 8 value corresponding to 0.4µs rounded up, and make
1038 	 * sure it stays below 0.6µs and within the allowable values.
1039 	 */
1040 	rate = clk_get_rate(dp->dpsub->apb_clk);
1041 	w = DIV_ROUND_UP(4 * rate, 1000 * 1000 * 10 * 8) * 8;
1042 	if (w > 6 * rate / (1000 * 1000 * 10) || w > 48) {
1043 		dev_err(dp->dev, "aclk frequency too high\n");
1044 		return -EINVAL;
1045 	}
1046 
1047 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_CLK_DIVIDER,
1048 			(w << ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT) |
1049 			(rate / (1000 * 1000)));
1050 
1051 	dp->aux.name = "ZynqMP DP AUX";
1052 	dp->aux.dev = dp->dev;
1053 	dp->aux.drm_dev = dp->bridge.dev;
1054 	dp->aux.transfer = zynqmp_dp_aux_transfer;
1055 
1056 	return drm_dp_aux_register(&dp->aux);
1057 }
1058 
1059 /**
1060  * zynqmp_dp_aux_cleanup - Cleanup the DP AUX
1061  * @dp: DisplayPort IP core structure
1062  *
1063  * Unregister the DP AUX adapter.
1064  */
1065 static void zynqmp_dp_aux_cleanup(struct zynqmp_dp *dp)
1066 {
1067 	drm_dp_aux_unregister(&dp->aux);
1068 }
1069 
1070 /* -----------------------------------------------------------------------------
1071  * DisplayPort Generic Support
1072  */
1073 
1074 /**
1075  * zynqmp_dp_update_misc - Write the misc registers
1076  * @dp: DisplayPort IP core structure
1077  *
1078  * The misc register values are stored in the structure, and this
1079  * function applies the values into the registers.
1080  */
1081 static void zynqmp_dp_update_misc(struct zynqmp_dp *dp)
1082 {
1083 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC0, dp->config.misc0);
1084 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC1, dp->config.misc1);
1085 }
1086 
1087 /**
1088  * zynqmp_dp_set_format - Set the input format
1089  * @dp: DisplayPort IP core structure
1090  * @info: Display info
1091  * @format: input format
1092  * @bpc: bits per component
1093  *
1094  * Update misc register values based on input @format and @bpc.
1095  *
1096  * Return: 0 on success, or -EINVAL.
1097  */
1098 static int zynqmp_dp_set_format(struct zynqmp_dp *dp,
1099 				const struct drm_display_info *info,
1100 				enum zynqmp_dpsub_format format,
1101 				unsigned int bpc)
1102 {
1103 	struct zynqmp_dp_config *config = &dp->config;
1104 	unsigned int num_colors;
1105 
1106 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK;
1107 	config->misc1 &= ~ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1108 
1109 	switch (format) {
1110 	case ZYNQMP_DPSUB_FORMAT_RGB:
1111 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB;
1112 		num_colors = 3;
1113 		break;
1114 
1115 	case ZYNQMP_DPSUB_FORMAT_YCRCB444:
1116 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444;
1117 		num_colors = 3;
1118 		break;
1119 
1120 	case ZYNQMP_DPSUB_FORMAT_YCRCB422:
1121 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422;
1122 		num_colors = 2;
1123 		break;
1124 
1125 	case ZYNQMP_DPSUB_FORMAT_YONLY:
1126 		config->misc1 |= ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1127 		num_colors = 1;
1128 		break;
1129 
1130 	default:
1131 		dev_err(dp->dev, "Invalid colormetry in DT\n");
1132 		return -EINVAL;
1133 	}
1134 
1135 	if (info && info->bpc && bpc > info->bpc) {
1136 		dev_warn(dp->dev,
1137 			 "downgrading requested %ubpc to display limit %ubpc\n",
1138 			 bpc, info->bpc);
1139 		bpc = info->bpc;
1140 	}
1141 
1142 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK;
1143 
1144 	switch (bpc) {
1145 	case 6:
1146 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6;
1147 		break;
1148 	case 8:
1149 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1150 		break;
1151 	case 10:
1152 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10;
1153 		break;
1154 	case 12:
1155 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12;
1156 		break;
1157 	case 16:
1158 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16;
1159 		break;
1160 	default:
1161 		dev_warn(dp->dev, "Not supported bpc (%u). fall back to 8bpc\n",
1162 			 bpc);
1163 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1164 		bpc = 8;
1165 		break;
1166 	}
1167 
1168 	/* Update the current bpp based on the format. */
1169 	config->bpp = bpc * num_colors;
1170 
1171 	return 0;
1172 }
1173 
1174 /**
1175  * zynqmp_dp_encoder_mode_set_transfer_unit - Set the transfer unit values
1176  * @dp: DisplayPort IP core structure
1177  * @mode: requested display mode
1178  *
1179  * Set the transfer unit, and calculate all transfer unit size related values.
1180  * Calculation is based on DP and IP core specification.
1181  */
1182 static void
1183 zynqmp_dp_encoder_mode_set_transfer_unit(struct zynqmp_dp *dp,
1184 					 const struct drm_display_mode *mode)
1185 {
1186 	u32 tu = ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF;
1187 	u32 bw, vid_kbytes, avg_bytes_per_tu, init_wait;
1188 
1189 	/* Use the max transfer unit size (default) */
1190 	zynqmp_dp_write(dp, ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE, tu);
1191 
1192 	vid_kbytes = mode->clock * (dp->config.bpp / 8);
1193 	bw = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1194 	avg_bytes_per_tu = vid_kbytes * tu / (dp->mode.lane_cnt * bw / 1000);
1195 	zynqmp_dp_write(dp, ZYNQMP_DP_MIN_BYTES_PER_TU,
1196 			avg_bytes_per_tu / 1000);
1197 	zynqmp_dp_write(dp, ZYNQMP_DP_FRAC_BYTES_PER_TU,
1198 			avg_bytes_per_tu % 1000);
1199 
1200 	/* Configure the initial wait cycle based on transfer unit size */
1201 	if (tu < (avg_bytes_per_tu / 1000))
1202 		init_wait = 0;
1203 	else if ((avg_bytes_per_tu / 1000) <= 4)
1204 		init_wait = tu;
1205 	else
1206 		init_wait = tu - avg_bytes_per_tu / 1000;
1207 
1208 	zynqmp_dp_write(dp, ZYNQMP_DP_INIT_WAIT, init_wait);
1209 }
1210 
1211 /**
1212  * zynqmp_dp_encoder_mode_set_stream - Configure the main stream
1213  * @dp: DisplayPort IP core structure
1214  * @mode: requested display mode
1215  *
1216  * Configure the main stream based on the requested mode @mode. Calculation is
1217  * based on IP core specification.
1218  */
1219 static void zynqmp_dp_encoder_mode_set_stream(struct zynqmp_dp *dp,
1220 					      const struct drm_display_mode *mode)
1221 {
1222 	u8 lane_cnt = dp->mode.lane_cnt;
1223 	u32 reg, wpl;
1224 	unsigned int rate;
1225 
1226 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HTOTAL, mode->htotal);
1227 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VTOTAL, mode->vtotal);
1228 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_POLARITY,
1229 			(!!(mode->flags & DRM_MODE_FLAG_PVSYNC) <<
1230 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT) |
1231 			(!!(mode->flags & DRM_MODE_FLAG_PHSYNC) <<
1232 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT));
1233 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSWIDTH,
1234 			mode->hsync_end - mode->hsync_start);
1235 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSWIDTH,
1236 			mode->vsync_end - mode->vsync_start);
1237 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HRES, mode->hdisplay);
1238 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VRES, mode->vdisplay);
1239 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSTART,
1240 			mode->htotal - mode->hsync_start);
1241 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSTART,
1242 			mode->vtotal - mode->vsync_start);
1243 
1244 	/* In synchronous mode, set the dividers */
1245 	if (dp->config.misc0 & ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK) {
1246 		reg = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1247 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_N_VID, reg);
1248 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_M_VID, mode->clock);
1249 		rate = zynqmp_dpsub_get_audio_clk_rate(dp->dpsub);
1250 		if (rate) {
1251 			dev_dbg(dp->dev, "Audio rate: %d\n", rate / 512);
1252 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_N_AUD, reg);
1253 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_M_AUD, rate / 1000);
1254 		}
1255 	}
1256 
1257 	/* Only 2 channel audio is supported now */
1258 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1259 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CHANNELS, 1);
1260 
1261 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_PIX_WIDTH, 1);
1262 
1263 	/* Translate to the native 16 bit datapath based on IP core spec */
1264 	wpl = (mode->hdisplay * dp->config.bpp + 15) / 16;
1265 	reg = wpl + wpl % lane_cnt - lane_cnt;
1266 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_DATA_COUNT_PER_LANE, reg);
1267 }
1268 
1269 /* -----------------------------------------------------------------------------
1270  * DISP Configuration
1271  */
1272 
1273 /**
1274  * zynqmp_dp_disp_connected_live_layer - Return the first connected live layer
1275  * @dp: DisplayPort IP core structure
1276  *
1277  * Return: The first connected live display layer or NULL if none of the live
1278  * layers are connected.
1279  */
1280 static struct zynqmp_disp_layer *
1281 zynqmp_dp_disp_connected_live_layer(struct zynqmp_dp *dp)
1282 {
1283 	if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO))
1284 		return dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_VID];
1285 	else if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))
1286 		return dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_GFX];
1287 	else
1288 		return NULL;
1289 }
1290 
1291 static void zynqmp_dp_disp_enable(struct zynqmp_dp *dp,
1292 				  struct drm_bridge_state *old_bridge_state)
1293 {
1294 	struct zynqmp_disp_layer *layer;
1295 	struct drm_bridge_state *bridge_state;
1296 	u32 bus_fmt;
1297 
1298 	layer = zynqmp_dp_disp_connected_live_layer(dp);
1299 	if (!layer)
1300 		return;
1301 
1302 	bridge_state = drm_atomic_get_new_bridge_state(old_bridge_state->base.state,
1303 						       old_bridge_state->bridge);
1304 	if (WARN_ON(!bridge_state))
1305 		return;
1306 
1307 	bus_fmt = bridge_state->input_bus_cfg.format;
1308 	zynqmp_disp_layer_set_live_format(layer, bus_fmt);
1309 	zynqmp_disp_layer_enable(layer);
1310 
1311 	if (layer == dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_GFX])
1312 		zynqmp_disp_blend_set_global_alpha(dp->dpsub->disp, true, 255);
1313 	else
1314 		zynqmp_disp_blend_set_global_alpha(dp->dpsub->disp, false, 0);
1315 
1316 	zynqmp_disp_enable(dp->dpsub->disp);
1317 }
1318 
1319 static void zynqmp_dp_disp_disable(struct zynqmp_dp *dp,
1320 				   struct drm_bridge_state *old_bridge_state)
1321 {
1322 	struct zynqmp_disp_layer *layer;
1323 
1324 	layer = zynqmp_dp_disp_connected_live_layer(dp);
1325 	if (!layer)
1326 		return;
1327 
1328 	zynqmp_disp_disable(dp->dpsub->disp);
1329 	zynqmp_disp_layer_disable(layer);
1330 }
1331 
1332 /* -----------------------------------------------------------------------------
1333  * DRM Bridge
1334  */
1335 
1336 static int zynqmp_dp_bridge_attach(struct drm_bridge *bridge,
1337 				   enum drm_bridge_attach_flags flags)
1338 {
1339 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1340 	int ret;
1341 
1342 	/* Initialize and register the AUX adapter. */
1343 	ret = zynqmp_dp_aux_init(dp);
1344 	if (ret) {
1345 		dev_err(dp->dev, "failed to initialize DP aux\n");
1346 		return ret;
1347 	}
1348 
1349 	if (dp->next_bridge) {
1350 		ret = drm_bridge_attach(bridge->encoder, dp->next_bridge,
1351 					bridge, flags);
1352 		if (ret < 0)
1353 			goto error;
1354 	}
1355 
1356 	/* Now that initialisation is complete, enable interrupts. */
1357 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_ALL);
1358 
1359 	return 0;
1360 
1361 error:
1362 	zynqmp_dp_aux_cleanup(dp);
1363 	return ret;
1364 }
1365 
1366 static void zynqmp_dp_bridge_detach(struct drm_bridge *bridge)
1367 {
1368 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1369 
1370 	zynqmp_dp_aux_cleanup(dp);
1371 }
1372 
1373 static enum drm_mode_status
1374 zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge,
1375 			    const struct drm_display_info *info,
1376 			    const struct drm_display_mode *mode)
1377 {
1378 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1379 	int rate;
1380 
1381 	if (mode->clock > ZYNQMP_MAX_FREQ) {
1382 		dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n",
1383 			mode->name);
1384 		drm_mode_debug_printmodeline(mode);
1385 		return MODE_CLOCK_HIGH;
1386 	}
1387 
1388 	/* Check with link rate and lane count */
1389 	rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
1390 				  dp->link_config.max_lanes, dp->config.bpp);
1391 	if (mode->clock > rate) {
1392 		dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n",
1393 			mode->name);
1394 		drm_mode_debug_printmodeline(mode);
1395 		return MODE_CLOCK_HIGH;
1396 	}
1397 
1398 	return MODE_OK;
1399 }
1400 
1401 static void zynqmp_dp_bridge_atomic_enable(struct drm_bridge *bridge,
1402 					   struct drm_bridge_state *old_bridge_state)
1403 {
1404 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1405 	struct drm_atomic_state *state = old_bridge_state->base.state;
1406 	const struct drm_crtc_state *crtc_state;
1407 	const struct drm_display_mode *adjusted_mode;
1408 	const struct drm_display_mode *mode;
1409 	struct drm_connector *connector;
1410 	struct drm_crtc *crtc;
1411 	unsigned int i;
1412 	int rate;
1413 	int ret;
1414 
1415 	pm_runtime_get_sync(dp->dev);
1416 
1417 	zynqmp_dp_disp_enable(dp, old_bridge_state);
1418 
1419 	/*
1420 	 * Retrieve the CRTC mode and adjusted mode. This requires a little
1421 	 * dance to go from the bridge to the encoder, to the connector and to
1422 	 * the CRTC.
1423 	 */
1424 	connector = drm_atomic_get_new_connector_for_encoder(state,
1425 							     bridge->encoder);
1426 	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
1427 	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
1428 	adjusted_mode = &crtc_state->adjusted_mode;
1429 	mode = &crtc_state->mode;
1430 
1431 	zynqmp_dp_set_format(dp, &connector->display_info,
1432 			     ZYNQMP_DPSUB_FORMAT_RGB, 8);
1433 
1434 	/* Check again as bpp or format might have been changed */
1435 	rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
1436 				  dp->link_config.max_lanes, dp->config.bpp);
1437 	if (mode->clock > rate) {
1438 		dev_err(dp->dev, "mode %s has too high pixel rate\n",
1439 			mode->name);
1440 		drm_mode_debug_printmodeline(mode);
1441 	}
1442 
1443 	/* Configure the mode */
1444 	ret = zynqmp_dp_mode_configure(dp, adjusted_mode->clock, 0);
1445 	if (ret < 0) {
1446 		pm_runtime_put_sync(dp->dev);
1447 		return;
1448 	}
1449 
1450 	zynqmp_dp_encoder_mode_set_transfer_unit(dp, adjusted_mode);
1451 	zynqmp_dp_encoder_mode_set_stream(dp, adjusted_mode);
1452 
1453 	/* Enable the encoder */
1454 	dp->enabled = true;
1455 	zynqmp_dp_update_misc(dp);
1456 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1457 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 1);
1458 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, 0);
1459 	if (dp->status == connector_status_connected) {
1460 		for (i = 0; i < 3; i++) {
1461 			ret = drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER,
1462 						 DP_SET_POWER_D0);
1463 			if (ret == 1)
1464 				break;
1465 			usleep_range(300, 500);
1466 		}
1467 		/* Some monitors take time to wake up properly */
1468 		msleep(zynqmp_dp_power_on_delay_ms);
1469 	}
1470 	if (ret != 1)
1471 		dev_dbg(dp->dev, "DP aux failed\n");
1472 	else
1473 		zynqmp_dp_train_loop(dp);
1474 	zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET,
1475 			ZYNQMP_DP_SOFTWARE_RESET_ALL);
1476 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1);
1477 }
1478 
1479 static void zynqmp_dp_bridge_atomic_disable(struct drm_bridge *bridge,
1480 					    struct drm_bridge_state *old_bridge_state)
1481 {
1482 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1483 
1484 	dp->enabled = false;
1485 	cancel_work(&dp->hpd_work);
1486 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 0);
1487 	drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
1488 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1489 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1490 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1491 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 0);
1492 
1493 	zynqmp_dp_disp_disable(dp, old_bridge_state);
1494 
1495 	pm_runtime_put_sync(dp->dev);
1496 }
1497 
1498 #define ZYNQMP_DP_MIN_H_BACKPORCH	20
1499 
1500 static int zynqmp_dp_bridge_atomic_check(struct drm_bridge *bridge,
1501 					 struct drm_bridge_state *bridge_state,
1502 					 struct drm_crtc_state *crtc_state,
1503 					 struct drm_connector_state *conn_state)
1504 {
1505 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1506 	struct drm_display_mode *mode = &crtc_state->mode;
1507 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1508 	int diff = mode->htotal - mode->hsync_end;
1509 
1510 	/*
1511 	 * ZynqMP DP requires horizontal backporch to be greater than 12.
1512 	 * This limitation may not be compatible with the sink device.
1513 	 */
1514 	if (diff < ZYNQMP_DP_MIN_H_BACKPORCH) {
1515 		int vrefresh = (adjusted_mode->clock * 1000) /
1516 			       (adjusted_mode->vtotal * adjusted_mode->htotal);
1517 
1518 		dev_dbg(dp->dev, "hbackporch adjusted: %d to %d",
1519 			diff, ZYNQMP_DP_MIN_H_BACKPORCH - diff);
1520 		diff = ZYNQMP_DP_MIN_H_BACKPORCH - diff;
1521 		adjusted_mode->htotal += diff;
1522 		adjusted_mode->clock = adjusted_mode->vtotal *
1523 				       adjusted_mode->htotal * vrefresh / 1000;
1524 	}
1525 
1526 	return 0;
1527 }
1528 
1529 static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *bridge)
1530 {
1531 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1532 	struct zynqmp_dp_link_config *link_config = &dp->link_config;
1533 	u32 state, i;
1534 	int ret;
1535 
1536 	/*
1537 	 * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to
1538 	 * get the HPD signal with some monitors.
1539 	 */
1540 	for (i = 0; i < 10; i++) {
1541 		state = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
1542 		if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD)
1543 			break;
1544 		msleep(100);
1545 	}
1546 
1547 	if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD) {
1548 		ret = drm_dp_dpcd_read(&dp->aux, 0x0, dp->dpcd,
1549 				       sizeof(dp->dpcd));
1550 		if (ret < 0) {
1551 			dev_dbg(dp->dev, "DPCD read failed");
1552 			goto disconnected;
1553 		}
1554 
1555 		link_config->max_rate = min_t(int,
1556 					      drm_dp_max_link_rate(dp->dpcd),
1557 					      DP_HIGH_BIT_RATE2);
1558 		link_config->max_lanes = min_t(u8,
1559 					       drm_dp_max_lane_count(dp->dpcd),
1560 					       dp->num_lanes);
1561 
1562 		dp->status = connector_status_connected;
1563 		return connector_status_connected;
1564 	}
1565 
1566 disconnected:
1567 	dp->status = connector_status_disconnected;
1568 	return connector_status_disconnected;
1569 }
1570 
1571 static const struct drm_edid *zynqmp_dp_bridge_edid_read(struct drm_bridge *bridge,
1572 							 struct drm_connector *connector)
1573 {
1574 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1575 
1576 	return drm_edid_read_ddc(connector, &dp->aux.ddc);
1577 }
1578 
1579 static u32 *zynqmp_dp_bridge_default_bus_fmts(unsigned int *num_input_fmts)
1580 {
1581 	u32 *formats = kzalloc(sizeof(*formats), GFP_KERNEL);
1582 
1583 	if (formats)
1584 		*formats = MEDIA_BUS_FMT_FIXED;
1585 	*num_input_fmts = !!formats;
1586 
1587 	return formats;
1588 }
1589 
1590 static u32 *
1591 zynqmp_dp_bridge_get_input_bus_fmts(struct drm_bridge *bridge,
1592 				    struct drm_bridge_state *bridge_state,
1593 				    struct drm_crtc_state *crtc_state,
1594 				    struct drm_connector_state *conn_state,
1595 				    u32 output_fmt,
1596 				    unsigned int *num_input_fmts)
1597 {
1598 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1599 	struct zynqmp_disp_layer *layer;
1600 
1601 	layer = zynqmp_dp_disp_connected_live_layer(dp);
1602 	if (layer)
1603 		return zynqmp_disp_live_layer_formats(layer, num_input_fmts);
1604 	else
1605 		return zynqmp_dp_bridge_default_bus_fmts(num_input_fmts);
1606 }
1607 
1608 static const struct drm_bridge_funcs zynqmp_dp_bridge_funcs = {
1609 	.attach = zynqmp_dp_bridge_attach,
1610 	.detach = zynqmp_dp_bridge_detach,
1611 	.mode_valid = zynqmp_dp_bridge_mode_valid,
1612 	.atomic_enable = zynqmp_dp_bridge_atomic_enable,
1613 	.atomic_disable = zynqmp_dp_bridge_atomic_disable,
1614 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1615 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1616 	.atomic_reset = drm_atomic_helper_bridge_reset,
1617 	.atomic_check = zynqmp_dp_bridge_atomic_check,
1618 	.detect = zynqmp_dp_bridge_detect,
1619 	.edid_read = zynqmp_dp_bridge_edid_read,
1620 	.atomic_get_input_bus_fmts = zynqmp_dp_bridge_get_input_bus_fmts,
1621 };
1622 
1623 /* -----------------------------------------------------------------------------
1624  * Interrupt Handling
1625  */
1626 
1627 /**
1628  * zynqmp_dp_enable_vblank - Enable vblank
1629  * @dp: DisplayPort IP core structure
1630  *
1631  * Enable vblank interrupt
1632  */
1633 void zynqmp_dp_enable_vblank(struct zynqmp_dp *dp)
1634 {
1635 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_VBLANK_START);
1636 }
1637 
1638 /**
1639  * zynqmp_dp_disable_vblank - Disable vblank
1640  * @dp: DisplayPort IP core structure
1641  *
1642  * Disable vblank interrupt
1643  */
1644 void zynqmp_dp_disable_vblank(struct zynqmp_dp *dp)
1645 {
1646 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_VBLANK_START);
1647 }
1648 
1649 static void zynqmp_dp_hpd_work_func(struct work_struct *work)
1650 {
1651 	struct zynqmp_dp *dp = container_of(work, struct zynqmp_dp, hpd_work);
1652 	enum drm_connector_status status;
1653 
1654 	status = zynqmp_dp_bridge_detect(&dp->bridge);
1655 	drm_bridge_hpd_notify(&dp->bridge, status);
1656 }
1657 
1658 static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
1659 {
1660 	struct zynqmp_dp *dp = (struct zynqmp_dp *)data;
1661 	u32 status, mask;
1662 
1663 	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
1664 	/* clear status register as soon as we read it */
1665 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
1666 	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
1667 
1668 	/*
1669 	 * Status register may report some events, which corresponding interrupts
1670 	 * have been disabled. Filter out those events against interrupts' mask.
1671 	 */
1672 	status &= ~mask;
1673 
1674 	if (!status)
1675 		return IRQ_NONE;
1676 
1677 	/* dbg for diagnostic, but not much that the driver can do */
1678 	if (status & ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK)
1679 		dev_dbg_ratelimited(dp->dev, "underflow interrupt\n");
1680 	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
1681 		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
1682 
1683 	if (status & ZYNQMP_DP_INT_VBLANK_START)
1684 		zynqmp_dpsub_drm_handle_vblank(dp->dpsub);
1685 
1686 	if (status & ZYNQMP_DP_INT_HPD_EVENT)
1687 		schedule_work(&dp->hpd_work);
1688 
1689 	if (status & ZYNQMP_DP_INT_HPD_IRQ) {
1690 		int ret;
1691 		u8 status[DP_LINK_STATUS_SIZE + 2];
1692 
1693 		ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
1694 				       DP_LINK_STATUS_SIZE + 2);
1695 		if (ret < 0)
1696 			goto handled;
1697 
1698 		if (status[4] & DP_LINK_STATUS_UPDATED ||
1699 		    !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) ||
1700 		    !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) {
1701 			zynqmp_dp_train_loop(dp);
1702 		}
1703 	}
1704 
1705 handled:
1706 	return IRQ_HANDLED;
1707 }
1708 
1709 /* -----------------------------------------------------------------------------
1710  * Initialization & Cleanup
1711  */
1712 
1713 int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub)
1714 {
1715 	struct platform_device *pdev = to_platform_device(dpsub->dev);
1716 	struct drm_bridge *bridge;
1717 	struct zynqmp_dp *dp;
1718 	struct resource *res;
1719 	int ret;
1720 
1721 	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
1722 	if (!dp)
1723 		return -ENOMEM;
1724 
1725 	dp->dev = &pdev->dev;
1726 	dp->dpsub = dpsub;
1727 	dp->status = connector_status_disconnected;
1728 
1729 	INIT_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func);
1730 
1731 	/* Acquire all resources (IOMEM, IRQ and PHYs). */
1732 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp");
1733 	dp->iomem = devm_ioremap_resource(dp->dev, res);
1734 	if (IS_ERR(dp->iomem)) {
1735 		ret = PTR_ERR(dp->iomem);
1736 		goto err_free;
1737 	}
1738 
1739 	dp->irq = platform_get_irq(pdev, 0);
1740 	if (dp->irq < 0) {
1741 		ret = dp->irq;
1742 		goto err_free;
1743 	}
1744 
1745 	dp->reset = devm_reset_control_get(dp->dev, NULL);
1746 	if (IS_ERR(dp->reset)) {
1747 		if (PTR_ERR(dp->reset) != -EPROBE_DEFER)
1748 			dev_err(dp->dev, "failed to get reset: %ld\n",
1749 				PTR_ERR(dp->reset));
1750 		ret = PTR_ERR(dp->reset);
1751 		goto err_free;
1752 	}
1753 
1754 	ret = zynqmp_dp_reset(dp, true);
1755 	if (ret < 0)
1756 		goto err_free;
1757 
1758 	ret = zynqmp_dp_reset(dp, false);
1759 	if (ret < 0)
1760 		goto err_free;
1761 
1762 	ret = zynqmp_dp_phy_probe(dp);
1763 	if (ret)
1764 		goto err_reset;
1765 
1766 	/* Initialize the bridge. */
1767 	bridge = &dp->bridge;
1768 	bridge->funcs = &zynqmp_dp_bridge_funcs;
1769 	bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID
1770 		    | DRM_BRIDGE_OP_HPD;
1771 	bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
1772 	bridge->of_node = dp->dev->of_node;
1773 	dpsub->bridge = bridge;
1774 
1775 	/*
1776 	 * Acquire the next bridge in the chain. Ignore errors caused by port@5
1777 	 * not being connected for backward-compatibility with older DTs.
1778 	 */
1779 	ret = drm_of_find_panel_or_bridge(dp->dev->of_node, 5, 0, NULL,
1780 					  &dp->next_bridge);
1781 	if (ret < 0 && ret != -ENODEV)
1782 		goto err_reset;
1783 
1784 	/* Initialize the hardware. */
1785 	dp->config.misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK;
1786 	zynqmp_dp_set_format(dp, NULL, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1787 
1788 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1789 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1790 	zynqmp_dp_set(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
1791 	zynqmp_dp_write(dp, ZYNQMP_DP_FORCE_SCRAMBLER_RESET, 1);
1792 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1793 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1794 
1795 	ret = zynqmp_dp_phy_init(dp);
1796 	if (ret)
1797 		goto err_reset;
1798 
1799 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1);
1800 
1801 	/*
1802 	 * Now that the hardware is initialized and won't generate spurious
1803 	 * interrupts, request the IRQ.
1804 	 */
1805 	ret = devm_request_threaded_irq(dp->dev, dp->irq, NULL,
1806 					zynqmp_dp_irq_handler, IRQF_ONESHOT,
1807 					dev_name(dp->dev), dp);
1808 	if (ret < 0)
1809 		goto err_phy_exit;
1810 
1811 	dpsub->dp = dp;
1812 
1813 	dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n",
1814 		dp->num_lanes);
1815 
1816 	return 0;
1817 
1818 err_phy_exit:
1819 	zynqmp_dp_phy_exit(dp);
1820 err_reset:
1821 	zynqmp_dp_reset(dp, true);
1822 err_free:
1823 	kfree(dp);
1824 	return ret;
1825 }
1826 
1827 void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub)
1828 {
1829 	struct zynqmp_dp *dp = dpsub->dp;
1830 
1831 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL);
1832 	disable_irq(dp->irq);
1833 
1834 	cancel_work_sync(&dp->hpd_work);
1835 
1836 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1837 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1838 
1839 	zynqmp_dp_phy_exit(dp);
1840 	zynqmp_dp_reset(dp, true);
1841 }
1842