xref: /linux/drivers/gpu/drm/xlnx/zynqmp_dp.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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 	u8 bw_code;
260 	u8 lane_cnt;
261 	int pclock;
262 	const char *fmt;
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 device *dev;
300 	struct zynqmp_dpsub *dpsub;
301 	void __iomem *iomem;
302 	struct reset_control *reset;
303 	int irq;
304 
305 	struct drm_bridge bridge;
306 	struct drm_bridge *next_bridge;
307 
308 	struct zynqmp_dp_config config;
309 	struct drm_dp_aux aux;
310 	struct phy *phy[ZYNQMP_DP_MAX_LANES];
311 	u8 num_lanes;
312 	struct delayed_work hpd_work;
313 	enum drm_connector_status status;
314 	bool enabled;
315 
316 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
317 	struct zynqmp_dp_link_config link_config;
318 	struct zynqmp_dp_mode mode;
319 	u8 train_set[ZYNQMP_DP_MAX_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 voltage = 0, preemphasis = 0;
610 	u8 i;
611 
612 	for (i = 0; i < dp->mode.lane_cnt; i++) {
613 		u8 v = drm_dp_get_adjust_request_voltage(link_status, i);
614 		u8 p = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
615 
616 		if (v > voltage)
617 			voltage = v;
618 
619 		if (p > preemphasis)
620 			preemphasis = p;
621 	}
622 
623 	if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3)
624 		voltage |= DP_TRAIN_MAX_SWING_REACHED;
625 
626 	if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2)
627 		preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
628 
629 	for (i = 0; i < dp->mode.lane_cnt; i++)
630 		train_set[i] = voltage | preemphasis;
631 }
632 
633 /**
634  * zynqmp_dp_update_vs_emph - Update the training values
635  * @dp: DisplayPort IP core structure
636  *
637  * Update the training values based on the request from sink. The mapped values
638  * are predefined, and values(vs, pe, pc) are from the device manual.
639  *
640  * Return: 0 if vs and emph are updated successfully, or the error code returned
641  * by drm_dp_dpcd_write().
642  */
643 static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
644 {
645 	unsigned int i;
646 	int ret;
647 
648 	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->train_set,
649 				dp->mode.lane_cnt);
650 	if (ret < 0)
651 		return ret;
652 
653 	for (i = 0; i < dp->mode.lane_cnt; i++) {
654 		u32 reg = ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0 + i * 4;
655 		union phy_configure_opts opts = { 0 };
656 		u8 train = dp->train_set[i];
657 
658 		opts.dp.voltage[0] = (train & DP_TRAIN_VOLTAGE_SWING_MASK)
659 				   >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
660 		opts.dp.pre[0] = (train & DP_TRAIN_PRE_EMPHASIS_MASK)
661 			       >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
662 
663 		phy_configure(dp->phy[i], &opts);
664 
665 		zynqmp_dp_write(dp, reg, 0x2);
666 	}
667 
668 	return 0;
669 }
670 
671 /**
672  * zynqmp_dp_link_train_cr - Train clock recovery
673  * @dp: DisplayPort IP core structure
674  *
675  * Return: 0 if clock recovery train is done successfully, or corresponding
676  * error code.
677  */
678 static int zynqmp_dp_link_train_cr(struct zynqmp_dp *dp)
679 {
680 	u8 link_status[DP_LINK_STATUS_SIZE];
681 	u8 lane_cnt = dp->mode.lane_cnt;
682 	u8 vs = 0, tries = 0;
683 	u16 max_tries, i;
684 	bool cr_done;
685 	int ret;
686 
687 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
688 			DP_TRAINING_PATTERN_1);
689 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
690 				 DP_TRAINING_PATTERN_1 |
691 				 DP_LINK_SCRAMBLING_DISABLE);
692 	if (ret < 0)
693 		return ret;
694 
695 	/*
696 	 * 256 loops should be maximum iterations for 4 lanes and 4 values.
697 	 * So, This loop should exit before 512 iterations
698 	 */
699 	for (max_tries = 0; max_tries < 512; max_tries++) {
700 		ret = zynqmp_dp_update_vs_emph(dp);
701 		if (ret)
702 			return ret;
703 
704 		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
705 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
706 		if (ret < 0)
707 			return ret;
708 
709 		cr_done = drm_dp_clock_recovery_ok(link_status, lane_cnt);
710 		if (cr_done)
711 			break;
712 
713 		for (i = 0; i < lane_cnt; i++)
714 			if (!(dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED))
715 				break;
716 		if (i == lane_cnt)
717 			break;
718 
719 		if ((dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == vs)
720 			tries++;
721 		else
722 			tries = 0;
723 
724 		if (tries == DP_MAX_TRAINING_TRIES)
725 			break;
726 
727 		vs = dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
728 		zynqmp_dp_adjust_train(dp, link_status);
729 	}
730 
731 	if (!cr_done)
732 		return -EIO;
733 
734 	return 0;
735 }
736 
737 /**
738  * zynqmp_dp_link_train_ce - Train channel equalization
739  * @dp: DisplayPort IP core structure
740  *
741  * Return: 0 if channel equalization train is done successfully, or
742  * corresponding error code.
743  */
744 static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
745 {
746 	u8 link_status[DP_LINK_STATUS_SIZE];
747 	u8 lane_cnt = dp->mode.lane_cnt;
748 	u32 pat, tries;
749 	int ret;
750 	bool ce_done;
751 
752 	if (dp->dpcd[DP_DPCD_REV] >= DP_V1_2 &&
753 	    dp->dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED)
754 		pat = DP_TRAINING_PATTERN_3;
755 	else
756 		pat = DP_TRAINING_PATTERN_2;
757 
758 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET, pat);
759 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
760 				 pat | DP_LINK_SCRAMBLING_DISABLE);
761 	if (ret < 0)
762 		return ret;
763 
764 	for (tries = 0; tries < DP_MAX_TRAINING_TRIES; tries++) {
765 		ret = zynqmp_dp_update_vs_emph(dp);
766 		if (ret)
767 			return ret;
768 
769 		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
770 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
771 		if (ret < 0)
772 			return ret;
773 
774 		ce_done = drm_dp_channel_eq_ok(link_status, lane_cnt);
775 		if (ce_done)
776 			break;
777 
778 		zynqmp_dp_adjust_train(dp, link_status);
779 	}
780 
781 	if (!ce_done)
782 		return -EIO;
783 
784 	return 0;
785 }
786 
787 /**
788  * zynqmp_dp_train - Train the link
789  * @dp: DisplayPort IP core structure
790  *
791  * Return: 0 if all trains are done successfully, or corresponding error code.
792  */
793 static int zynqmp_dp_train(struct zynqmp_dp *dp)
794 {
795 	u32 reg;
796 	u8 bw_code = dp->mode.bw_code;
797 	u8 lane_cnt = dp->mode.lane_cnt;
798 	u8 aux_lane_cnt = lane_cnt;
799 	bool enhanced;
800 	int ret;
801 
802 	zynqmp_dp_write(dp, ZYNQMP_DP_LANE_COUNT_SET, lane_cnt);
803 	enhanced = drm_dp_enhanced_frame_cap(dp->dpcd);
804 	if (enhanced) {
805 		zynqmp_dp_write(dp, ZYNQMP_DP_ENHANCED_FRAME_EN, 1);
806 		aux_lane_cnt |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
807 	}
808 
809 	if (dp->dpcd[3] & 0x1) {
810 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 1);
811 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL,
812 				   DP_SPREAD_AMP_0_5);
813 	} else {
814 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 0);
815 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL, 0);
816 	}
817 
818 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET, aux_lane_cnt);
819 	if (ret < 0) {
820 		dev_err(dp->dev, "failed to set lane count\n");
821 		return ret;
822 	}
823 
824 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
825 				 DP_SET_ANSI_8B10B);
826 	if (ret < 0) {
827 		dev_err(dp->dev, "failed to set ANSI 8B/10B encoding\n");
828 		return ret;
829 	}
830 
831 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LINK_BW_SET, bw_code);
832 	if (ret < 0) {
833 		dev_err(dp->dev, "failed to set DP bandwidth\n");
834 		return ret;
835 	}
836 
837 	zynqmp_dp_write(dp, ZYNQMP_DP_LINK_BW_SET, bw_code);
838 	switch (bw_code) {
839 	case DP_LINK_BW_1_62:
840 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G;
841 		break;
842 	case DP_LINK_BW_2_7:
843 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G;
844 		break;
845 	case DP_LINK_BW_5_4:
846 	default:
847 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G;
848 		break;
849 	}
850 
851 	zynqmp_dp_write(dp, ZYNQMP_DP_PHY_CLOCK_SELECT, reg);
852 	ret = zynqmp_dp_phy_ready(dp);
853 	if (ret < 0)
854 		return ret;
855 
856 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 1);
857 	memset(dp->train_set, 0, sizeof(dp->train_set));
858 	ret = zynqmp_dp_link_train_cr(dp);
859 	if (ret)
860 		return ret;
861 
862 	ret = zynqmp_dp_link_train_ce(dp);
863 	if (ret)
864 		return ret;
865 
866 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
867 				 DP_TRAINING_PATTERN_DISABLE);
868 	if (ret < 0) {
869 		dev_err(dp->dev, "failed to disable training pattern\n");
870 		return ret;
871 	}
872 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
873 			DP_TRAINING_PATTERN_DISABLE);
874 
875 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 0);
876 
877 	return 0;
878 }
879 
880 /**
881  * zynqmp_dp_train_loop - Downshift the link rate during training
882  * @dp: DisplayPort IP core structure
883  *
884  * Train the link by downshifting the link rate if training is not successful.
885  */
886 static void zynqmp_dp_train_loop(struct zynqmp_dp *dp)
887 {
888 	struct zynqmp_dp_mode *mode = &dp->mode;
889 	u8 bw = mode->bw_code;
890 	int ret;
891 
892 	do {
893 		if (dp->status == connector_status_disconnected ||
894 		    !dp->enabled)
895 			return;
896 
897 		ret = zynqmp_dp_train(dp);
898 		if (!ret)
899 			return;
900 
901 		ret = zynqmp_dp_mode_configure(dp, mode->pclock, bw);
902 		if (ret < 0)
903 			goto err_out;
904 
905 		bw = ret;
906 	} while (bw >= DP_LINK_BW_1_62);
907 
908 err_out:
909 	dev_err(dp->dev, "failed to train the DP link\n");
910 }
911 
912 /* -----------------------------------------------------------------------------
913  * DisplayPort AUX
914  */
915 
916 #define AUX_READ_BIT	0x1
917 
918 /**
919  * zynqmp_dp_aux_cmd_submit - Submit aux command
920  * @dp: DisplayPort IP core structure
921  * @cmd: aux command
922  * @addr: aux address
923  * @buf: buffer for command data
924  * @bytes: number of bytes for @buf
925  * @reply: reply code to be returned
926  *
927  * Submit an aux command. All aux related commands, native or i2c aux
928  * read/write, are submitted through this function. The function is mapped to
929  * the transfer function of struct drm_dp_aux. This function involves in
930  * multiple register reads/writes, thus synchronization is needed, and it is
931  * done by drm_dp_helper using @hw_mutex. The calling thread goes into sleep
932  * if there's no immediate reply to the command submission. The reply code is
933  * returned at @reply if @reply != NULL.
934  *
935  * Return: 0 if the command is submitted properly, or corresponding error code:
936  * -EBUSY when there is any request already being processed
937  * -ETIMEDOUT when receiving reply is timed out
938  * -EIO when received bytes are less than requested
939  */
940 static int zynqmp_dp_aux_cmd_submit(struct zynqmp_dp *dp, u32 cmd, u16 addr,
941 				    u8 *buf, u8 bytes, u8 *reply)
942 {
943 	bool is_read = (cmd & AUX_READ_BIT) ? true : false;
944 	u32 reg, i;
945 
946 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
947 	if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST)
948 		return -EBUSY;
949 
950 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_ADDRESS, addr);
951 	if (!is_read)
952 		for (i = 0; i < bytes; i++)
953 			zynqmp_dp_write(dp, ZYNQMP_DP_AUX_WRITE_FIFO,
954 					buf[i]);
955 
956 	reg = cmd << ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT;
957 	if (!buf || !bytes)
958 		reg |= ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY;
959 	else
960 		reg |= (bytes - 1) << ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT;
961 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_COMMAND, reg);
962 
963 	/* Wait for reply to be delivered upto 2ms */
964 	for (i = 0; ; i++) {
965 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
966 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY)
967 			break;
968 
969 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT ||
970 		    i == 2)
971 			return -ETIMEDOUT;
972 
973 		usleep_range(1000, 1100);
974 	}
975 
976 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_CODE);
977 	if (reply)
978 		*reply = reg;
979 
980 	if (is_read &&
981 	    (reg == ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK ||
982 	     reg == ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK)) {
983 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_REPLY_DATA_COUNT);
984 		if ((reg & ZYNQMP_DP_REPLY_DATA_COUNT_MASK) != bytes)
985 			return -EIO;
986 
987 		for (i = 0; i < bytes; i++)
988 			buf[i] = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_DATA);
989 	}
990 
991 	return 0;
992 }
993 
994 static ssize_t
995 zynqmp_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
996 {
997 	struct zynqmp_dp *dp = container_of(aux, struct zynqmp_dp, aux);
998 	int ret;
999 	unsigned int i, iter;
1000 
1001 	/* Number of loops = timeout in msec / aux delay (400 usec) */
1002 	iter = zynqmp_dp_aux_timeout_ms * 1000 / 400;
1003 	iter = iter ? iter : 1;
1004 
1005 	for (i = 0; i < iter; i++) {
1006 		ret = zynqmp_dp_aux_cmd_submit(dp, msg->request, msg->address,
1007 					       msg->buffer, msg->size,
1008 					       &msg->reply);
1009 		if (!ret) {
1010 			dev_dbg(dp->dev, "aux %d retries\n", i);
1011 			return msg->size;
1012 		}
1013 
1014 		if (dp->status == connector_status_disconnected) {
1015 			dev_dbg(dp->dev, "no connected aux device\n");
1016 			return -ENODEV;
1017 		}
1018 
1019 		usleep_range(400, 500);
1020 	}
1021 
1022 	dev_dbg(dp->dev, "failed to do aux transfer (%d)\n", ret);
1023 
1024 	return ret;
1025 }
1026 
1027 /**
1028  * zynqmp_dp_aux_init - Initialize and register the DP AUX
1029  * @dp: DisplayPort IP core structure
1030  *
1031  * Program the AUX clock divider and filter and register the DP AUX adapter.
1032  *
1033  * Return: 0 on success, error value otherwise
1034  */
1035 static int zynqmp_dp_aux_init(struct zynqmp_dp *dp)
1036 {
1037 	unsigned long rate;
1038 	unsigned int w;
1039 
1040 	/*
1041 	 * The AUX_SIGNAL_WIDTH_FILTER is the number of APB clock cycles
1042 	 * corresponding to the AUX pulse. Allowable values are 8, 16, 24, 32,
1043 	 * 40 and 48. The AUX pulse width must be between 0.4µs and 0.6µs,
1044 	 * compute the w / 8 value corresponding to 0.4µs rounded up, and make
1045 	 * sure it stays below 0.6µs and within the allowable values.
1046 	 */
1047 	rate = clk_get_rate(dp->dpsub->apb_clk);
1048 	w = DIV_ROUND_UP(4 * rate, 1000 * 1000 * 10 * 8) * 8;
1049 	if (w > 6 * rate / (1000 * 1000 * 10) || w > 48) {
1050 		dev_err(dp->dev, "aclk frequency too high\n");
1051 		return -EINVAL;
1052 	}
1053 
1054 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_CLK_DIVIDER,
1055 			(w << ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT) |
1056 			(rate / (1000 * 1000)));
1057 
1058 	dp->aux.name = "ZynqMP DP AUX";
1059 	dp->aux.dev = dp->dev;
1060 	dp->aux.drm_dev = dp->bridge.dev;
1061 	dp->aux.transfer = zynqmp_dp_aux_transfer;
1062 
1063 	return drm_dp_aux_register(&dp->aux);
1064 }
1065 
1066 /**
1067  * zynqmp_dp_aux_cleanup - Cleanup the DP AUX
1068  * @dp: DisplayPort IP core structure
1069  *
1070  * Unregister the DP AUX adapter.
1071  */
1072 static void zynqmp_dp_aux_cleanup(struct zynqmp_dp *dp)
1073 {
1074 	drm_dp_aux_unregister(&dp->aux);
1075 }
1076 
1077 /* -----------------------------------------------------------------------------
1078  * DisplayPort Generic Support
1079  */
1080 
1081 /**
1082  * zynqmp_dp_update_misc - Write the misc registers
1083  * @dp: DisplayPort IP core structure
1084  *
1085  * The misc register values are stored in the structure, and this
1086  * function applies the values into the registers.
1087  */
1088 static void zynqmp_dp_update_misc(struct zynqmp_dp *dp)
1089 {
1090 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC0, dp->config.misc0);
1091 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC1, dp->config.misc1);
1092 }
1093 
1094 /**
1095  * zynqmp_dp_set_format - Set the input format
1096  * @dp: DisplayPort IP core structure
1097  * @info: Display info
1098  * @format: input format
1099  * @bpc: bits per component
1100  *
1101  * Update misc register values based on input @format and @bpc.
1102  *
1103  * Return: 0 on success, or -EINVAL.
1104  */
1105 static int zynqmp_dp_set_format(struct zynqmp_dp *dp,
1106 				const struct drm_display_info *info,
1107 				enum zynqmp_dpsub_format format,
1108 				unsigned int bpc)
1109 {
1110 	struct zynqmp_dp_config *config = &dp->config;
1111 	unsigned int num_colors;
1112 
1113 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK;
1114 	config->misc1 &= ~ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1115 
1116 	switch (format) {
1117 	case ZYNQMP_DPSUB_FORMAT_RGB:
1118 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB;
1119 		num_colors = 3;
1120 		break;
1121 
1122 	case ZYNQMP_DPSUB_FORMAT_YCRCB444:
1123 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444;
1124 		num_colors = 3;
1125 		break;
1126 
1127 	case ZYNQMP_DPSUB_FORMAT_YCRCB422:
1128 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422;
1129 		num_colors = 2;
1130 		break;
1131 
1132 	case ZYNQMP_DPSUB_FORMAT_YONLY:
1133 		config->misc1 |= ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1134 		num_colors = 1;
1135 		break;
1136 
1137 	default:
1138 		dev_err(dp->dev, "Invalid colormetry in DT\n");
1139 		return -EINVAL;
1140 	}
1141 
1142 	if (info && info->bpc && bpc > info->bpc) {
1143 		dev_warn(dp->dev,
1144 			 "downgrading requested %ubpc to display limit %ubpc\n",
1145 			 bpc, info->bpc);
1146 		bpc = info->bpc;
1147 	}
1148 
1149 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK;
1150 
1151 	switch (bpc) {
1152 	case 6:
1153 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6;
1154 		break;
1155 	case 8:
1156 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1157 		break;
1158 	case 10:
1159 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10;
1160 		break;
1161 	case 12:
1162 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12;
1163 		break;
1164 	case 16:
1165 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16;
1166 		break;
1167 	default:
1168 		dev_warn(dp->dev, "Not supported bpc (%u). fall back to 8bpc\n",
1169 			 bpc);
1170 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1171 		bpc = 8;
1172 		break;
1173 	}
1174 
1175 	/* Update the current bpp based on the format. */
1176 	config->bpp = bpc * num_colors;
1177 
1178 	return 0;
1179 }
1180 
1181 /**
1182  * zynqmp_dp_encoder_mode_set_transfer_unit - Set the transfer unit values
1183  * @dp: DisplayPort IP core structure
1184  * @mode: requested display mode
1185  *
1186  * Set the transfer unit, and calculate all transfer unit size related values.
1187  * Calculation is based on DP and IP core specification.
1188  */
1189 static void
1190 zynqmp_dp_encoder_mode_set_transfer_unit(struct zynqmp_dp *dp,
1191 					 const struct drm_display_mode *mode)
1192 {
1193 	u32 tu = ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF;
1194 	u32 bw, vid_kbytes, avg_bytes_per_tu, init_wait;
1195 
1196 	/* Use the max transfer unit size (default) */
1197 	zynqmp_dp_write(dp, ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE, tu);
1198 
1199 	vid_kbytes = mode->clock * (dp->config.bpp / 8);
1200 	bw = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1201 	avg_bytes_per_tu = vid_kbytes * tu / (dp->mode.lane_cnt * bw / 1000);
1202 	zynqmp_dp_write(dp, ZYNQMP_DP_MIN_BYTES_PER_TU,
1203 			avg_bytes_per_tu / 1000);
1204 	zynqmp_dp_write(dp, ZYNQMP_DP_FRAC_BYTES_PER_TU,
1205 			avg_bytes_per_tu % 1000);
1206 
1207 	/* Configure the initial wait cycle based on transfer unit size */
1208 	if (tu < (avg_bytes_per_tu / 1000))
1209 		init_wait = 0;
1210 	else if ((avg_bytes_per_tu / 1000) <= 4)
1211 		init_wait = tu;
1212 	else
1213 		init_wait = tu - avg_bytes_per_tu / 1000;
1214 
1215 	zynqmp_dp_write(dp, ZYNQMP_DP_INIT_WAIT, init_wait);
1216 }
1217 
1218 /**
1219  * zynqmp_dp_encoder_mode_set_stream - Configure the main stream
1220  * @dp: DisplayPort IP core structure
1221  * @mode: requested display mode
1222  *
1223  * Configure the main stream based on the requested mode @mode. Calculation is
1224  * based on IP core specification.
1225  */
1226 static void zynqmp_dp_encoder_mode_set_stream(struct zynqmp_dp *dp,
1227 					      const struct drm_display_mode *mode)
1228 {
1229 	u8 lane_cnt = dp->mode.lane_cnt;
1230 	u32 reg, wpl;
1231 	unsigned int rate;
1232 
1233 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HTOTAL, mode->htotal);
1234 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VTOTAL, mode->vtotal);
1235 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_POLARITY,
1236 			(!!(mode->flags & DRM_MODE_FLAG_PVSYNC) <<
1237 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT) |
1238 			(!!(mode->flags & DRM_MODE_FLAG_PHSYNC) <<
1239 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT));
1240 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSWIDTH,
1241 			mode->hsync_end - mode->hsync_start);
1242 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSWIDTH,
1243 			mode->vsync_end - mode->vsync_start);
1244 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HRES, mode->hdisplay);
1245 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VRES, mode->vdisplay);
1246 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSTART,
1247 			mode->htotal - mode->hsync_start);
1248 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSTART,
1249 			mode->vtotal - mode->vsync_start);
1250 
1251 	/* In synchronous mode, set the dividers */
1252 	if (dp->config.misc0 & ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK) {
1253 		reg = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1254 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_N_VID, reg);
1255 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_M_VID, mode->clock);
1256 		rate = zynqmp_dpsub_get_audio_clk_rate(dp->dpsub);
1257 		if (rate) {
1258 			dev_dbg(dp->dev, "Audio rate: %d\n", rate / 512);
1259 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_N_AUD, reg);
1260 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_M_AUD, rate / 1000);
1261 		}
1262 	}
1263 
1264 	/* Only 2 channel audio is supported now */
1265 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1266 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CHANNELS, 1);
1267 
1268 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_PIX_WIDTH, 1);
1269 
1270 	/* Translate to the native 16 bit datapath based on IP core spec */
1271 	wpl = (mode->hdisplay * dp->config.bpp + 15) / 16;
1272 	reg = wpl + wpl % lane_cnt - lane_cnt;
1273 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_DATA_COUNT_PER_LANE, reg);
1274 }
1275 
1276 /* -----------------------------------------------------------------------------
1277  * DISP Configuration
1278  */
1279 
1280 /**
1281  * zynqmp_dp_disp_connected_live_layer - Return the first connected live layer
1282  * @dp: DisplayPort IP core structure
1283  *
1284  * Return: The first connected live display layer or NULL if none of the live
1285  * layers are connected.
1286  */
1287 static struct zynqmp_disp_layer *
1288 zynqmp_dp_disp_connected_live_layer(struct zynqmp_dp *dp)
1289 {
1290 	if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO))
1291 		return dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_VID];
1292 	else if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))
1293 		return dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_GFX];
1294 	else
1295 		return NULL;
1296 }
1297 
1298 static void zynqmp_dp_disp_enable(struct zynqmp_dp *dp,
1299 				  struct drm_bridge_state *old_bridge_state)
1300 {
1301 	struct zynqmp_disp_layer *layer;
1302 	struct drm_bridge_state *bridge_state;
1303 	u32 bus_fmt;
1304 
1305 	layer = zynqmp_dp_disp_connected_live_layer(dp);
1306 	if (!layer)
1307 		return;
1308 
1309 	bridge_state = drm_atomic_get_new_bridge_state(old_bridge_state->base.state,
1310 						       old_bridge_state->bridge);
1311 	if (WARN_ON(!bridge_state))
1312 		return;
1313 
1314 	bus_fmt = bridge_state->input_bus_cfg.format;
1315 	zynqmp_disp_layer_set_live_format(layer, bus_fmt);
1316 	zynqmp_disp_layer_enable(layer);
1317 
1318 	if (layer == dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_GFX])
1319 		zynqmp_disp_blend_set_global_alpha(dp->dpsub->disp, true, 255);
1320 	else
1321 		zynqmp_disp_blend_set_global_alpha(dp->dpsub->disp, false, 0);
1322 
1323 	zynqmp_disp_enable(dp->dpsub->disp);
1324 }
1325 
1326 static void zynqmp_dp_disp_disable(struct zynqmp_dp *dp,
1327 				   struct drm_bridge_state *old_bridge_state)
1328 {
1329 	struct zynqmp_disp_layer *layer;
1330 
1331 	layer = zynqmp_dp_disp_connected_live_layer(dp);
1332 	if (!layer)
1333 		return;
1334 
1335 	zynqmp_disp_disable(dp->dpsub->disp);
1336 	zynqmp_disp_layer_disable(layer);
1337 }
1338 
1339 /* -----------------------------------------------------------------------------
1340  * DRM Bridge
1341  */
1342 
1343 static int zynqmp_dp_bridge_attach(struct drm_bridge *bridge,
1344 				   enum drm_bridge_attach_flags flags)
1345 {
1346 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1347 	int ret;
1348 
1349 	/* Initialize and register the AUX adapter. */
1350 	ret = zynqmp_dp_aux_init(dp);
1351 	if (ret) {
1352 		dev_err(dp->dev, "failed to initialize DP aux\n");
1353 		return ret;
1354 	}
1355 
1356 	if (dp->next_bridge) {
1357 		ret = drm_bridge_attach(bridge->encoder, dp->next_bridge,
1358 					bridge, flags);
1359 		if (ret < 0)
1360 			goto error;
1361 	}
1362 
1363 	/* Now that initialisation is complete, enable interrupts. */
1364 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_ALL);
1365 
1366 	return 0;
1367 
1368 error:
1369 	zynqmp_dp_aux_cleanup(dp);
1370 	return ret;
1371 }
1372 
1373 static void zynqmp_dp_bridge_detach(struct drm_bridge *bridge)
1374 {
1375 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1376 
1377 	zynqmp_dp_aux_cleanup(dp);
1378 }
1379 
1380 static enum drm_mode_status
1381 zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge,
1382 			    const struct drm_display_info *info,
1383 			    const struct drm_display_mode *mode)
1384 {
1385 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1386 	int rate;
1387 
1388 	if (mode->clock > ZYNQMP_MAX_FREQ) {
1389 		dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n",
1390 			mode->name);
1391 		drm_mode_debug_printmodeline(mode);
1392 		return MODE_CLOCK_HIGH;
1393 	}
1394 
1395 	/* Check with link rate and lane count */
1396 	rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
1397 				  dp->link_config.max_lanes, dp->config.bpp);
1398 	if (mode->clock > rate) {
1399 		dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n",
1400 			mode->name);
1401 		drm_mode_debug_printmodeline(mode);
1402 		return MODE_CLOCK_HIGH;
1403 	}
1404 
1405 	return MODE_OK;
1406 }
1407 
1408 static void zynqmp_dp_bridge_atomic_enable(struct drm_bridge *bridge,
1409 					   struct drm_bridge_state *old_bridge_state)
1410 {
1411 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1412 	struct drm_atomic_state *state = old_bridge_state->base.state;
1413 	const struct drm_crtc_state *crtc_state;
1414 	const struct drm_display_mode *adjusted_mode;
1415 	const struct drm_display_mode *mode;
1416 	struct drm_connector *connector;
1417 	struct drm_crtc *crtc;
1418 	unsigned int i;
1419 	int rate;
1420 	int ret;
1421 
1422 	pm_runtime_get_sync(dp->dev);
1423 
1424 	zynqmp_dp_disp_enable(dp, old_bridge_state);
1425 
1426 	/*
1427 	 * Retrieve the CRTC mode and adjusted mode. This requires a little
1428 	 * dance to go from the bridge to the encoder, to the connector and to
1429 	 * the CRTC.
1430 	 */
1431 	connector = drm_atomic_get_new_connector_for_encoder(state,
1432 							     bridge->encoder);
1433 	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
1434 	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
1435 	adjusted_mode = &crtc_state->adjusted_mode;
1436 	mode = &crtc_state->mode;
1437 
1438 	zynqmp_dp_set_format(dp, &connector->display_info,
1439 			     ZYNQMP_DPSUB_FORMAT_RGB, 8);
1440 
1441 	/* Check again as bpp or format might have been changed */
1442 	rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
1443 				  dp->link_config.max_lanes, dp->config.bpp);
1444 	if (mode->clock > rate) {
1445 		dev_err(dp->dev, "mode %s has too high pixel rate\n",
1446 			mode->name);
1447 		drm_mode_debug_printmodeline(mode);
1448 	}
1449 
1450 	/* Configure the mode */
1451 	ret = zynqmp_dp_mode_configure(dp, adjusted_mode->clock, 0);
1452 	if (ret < 0) {
1453 		pm_runtime_put_sync(dp->dev);
1454 		return;
1455 	}
1456 
1457 	zynqmp_dp_encoder_mode_set_transfer_unit(dp, adjusted_mode);
1458 	zynqmp_dp_encoder_mode_set_stream(dp, adjusted_mode);
1459 
1460 	/* Enable the encoder */
1461 	dp->enabled = true;
1462 	zynqmp_dp_update_misc(dp);
1463 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1464 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 1);
1465 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, 0);
1466 	if (dp->status == connector_status_connected) {
1467 		for (i = 0; i < 3; i++) {
1468 			ret = drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER,
1469 						 DP_SET_POWER_D0);
1470 			if (ret == 1)
1471 				break;
1472 			usleep_range(300, 500);
1473 		}
1474 		/* Some monitors take time to wake up properly */
1475 		msleep(zynqmp_dp_power_on_delay_ms);
1476 	}
1477 	if (ret != 1)
1478 		dev_dbg(dp->dev, "DP aux failed\n");
1479 	else
1480 		zynqmp_dp_train_loop(dp);
1481 	zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET,
1482 			ZYNQMP_DP_SOFTWARE_RESET_ALL);
1483 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1);
1484 }
1485 
1486 static void zynqmp_dp_bridge_atomic_disable(struct drm_bridge *bridge,
1487 					    struct drm_bridge_state *old_bridge_state)
1488 {
1489 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1490 
1491 	dp->enabled = false;
1492 	cancel_delayed_work(&dp->hpd_work);
1493 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 0);
1494 	drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
1495 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1496 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1497 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1498 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 0);
1499 
1500 	zynqmp_dp_disp_disable(dp, old_bridge_state);
1501 
1502 	pm_runtime_put_sync(dp->dev);
1503 }
1504 
1505 #define ZYNQMP_DP_MIN_H_BACKPORCH	20
1506 
1507 static int zynqmp_dp_bridge_atomic_check(struct drm_bridge *bridge,
1508 					 struct drm_bridge_state *bridge_state,
1509 					 struct drm_crtc_state *crtc_state,
1510 					 struct drm_connector_state *conn_state)
1511 {
1512 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1513 	struct drm_display_mode *mode = &crtc_state->mode;
1514 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1515 	int diff = mode->htotal - mode->hsync_end;
1516 
1517 	/*
1518 	 * ZynqMP DP requires horizontal backporch to be greater than 12.
1519 	 * This limitation may not be compatible with the sink device.
1520 	 */
1521 	if (diff < ZYNQMP_DP_MIN_H_BACKPORCH) {
1522 		int vrefresh = (adjusted_mode->clock * 1000) /
1523 			       (adjusted_mode->vtotal * adjusted_mode->htotal);
1524 
1525 		dev_dbg(dp->dev, "hbackporch adjusted: %d to %d",
1526 			diff, ZYNQMP_DP_MIN_H_BACKPORCH - diff);
1527 		diff = ZYNQMP_DP_MIN_H_BACKPORCH - diff;
1528 		adjusted_mode->htotal += diff;
1529 		adjusted_mode->clock = adjusted_mode->vtotal *
1530 				       adjusted_mode->htotal * vrefresh / 1000;
1531 	}
1532 
1533 	return 0;
1534 }
1535 
1536 static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *bridge)
1537 {
1538 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1539 	struct zynqmp_dp_link_config *link_config = &dp->link_config;
1540 	u32 state, i;
1541 	int ret;
1542 
1543 	/*
1544 	 * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to
1545 	 * get the HPD signal with some monitors.
1546 	 */
1547 	for (i = 0; i < 10; i++) {
1548 		state = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
1549 		if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD)
1550 			break;
1551 		msleep(100);
1552 	}
1553 
1554 	if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD) {
1555 		ret = drm_dp_dpcd_read(&dp->aux, 0x0, dp->dpcd,
1556 				       sizeof(dp->dpcd));
1557 		if (ret < 0) {
1558 			dev_dbg(dp->dev, "DPCD read failed");
1559 			goto disconnected;
1560 		}
1561 
1562 		link_config->max_rate = min_t(int,
1563 					      drm_dp_max_link_rate(dp->dpcd),
1564 					      DP_HIGH_BIT_RATE2);
1565 		link_config->max_lanes = min_t(u8,
1566 					       drm_dp_max_lane_count(dp->dpcd),
1567 					       dp->num_lanes);
1568 
1569 		dp->status = connector_status_connected;
1570 		return connector_status_connected;
1571 	}
1572 
1573 disconnected:
1574 	dp->status = connector_status_disconnected;
1575 	return connector_status_disconnected;
1576 }
1577 
1578 static const struct drm_edid *zynqmp_dp_bridge_edid_read(struct drm_bridge *bridge,
1579 							 struct drm_connector *connector)
1580 {
1581 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1582 
1583 	return drm_edid_read_ddc(connector, &dp->aux.ddc);
1584 }
1585 
1586 static u32 *zynqmp_dp_bridge_default_bus_fmts(unsigned int *num_input_fmts)
1587 {
1588 	u32 *formats = kzalloc(sizeof(*formats), GFP_KERNEL);
1589 
1590 	if (formats)
1591 		*formats = MEDIA_BUS_FMT_FIXED;
1592 	*num_input_fmts = !!formats;
1593 
1594 	return formats;
1595 }
1596 
1597 static u32 *
1598 zynqmp_dp_bridge_get_input_bus_fmts(struct drm_bridge *bridge,
1599 				    struct drm_bridge_state *bridge_state,
1600 				    struct drm_crtc_state *crtc_state,
1601 				    struct drm_connector_state *conn_state,
1602 				    u32 output_fmt,
1603 				    unsigned int *num_input_fmts)
1604 {
1605 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1606 	struct zynqmp_disp_layer *layer;
1607 
1608 	layer = zynqmp_dp_disp_connected_live_layer(dp);
1609 	if (layer)
1610 		return zynqmp_disp_live_layer_formats(layer, num_input_fmts);
1611 	else
1612 		return zynqmp_dp_bridge_default_bus_fmts(num_input_fmts);
1613 }
1614 
1615 static const struct drm_bridge_funcs zynqmp_dp_bridge_funcs = {
1616 	.attach = zynqmp_dp_bridge_attach,
1617 	.detach = zynqmp_dp_bridge_detach,
1618 	.mode_valid = zynqmp_dp_bridge_mode_valid,
1619 	.atomic_enable = zynqmp_dp_bridge_atomic_enable,
1620 	.atomic_disable = zynqmp_dp_bridge_atomic_disable,
1621 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1622 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1623 	.atomic_reset = drm_atomic_helper_bridge_reset,
1624 	.atomic_check = zynqmp_dp_bridge_atomic_check,
1625 	.detect = zynqmp_dp_bridge_detect,
1626 	.edid_read = zynqmp_dp_bridge_edid_read,
1627 	.atomic_get_input_bus_fmts = zynqmp_dp_bridge_get_input_bus_fmts,
1628 };
1629 
1630 /* -----------------------------------------------------------------------------
1631  * Interrupt Handling
1632  */
1633 
1634 /**
1635  * zynqmp_dp_enable_vblank - Enable vblank
1636  * @dp: DisplayPort IP core structure
1637  *
1638  * Enable vblank interrupt
1639  */
1640 void zynqmp_dp_enable_vblank(struct zynqmp_dp *dp)
1641 {
1642 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_VBLANK_START);
1643 }
1644 
1645 /**
1646  * zynqmp_dp_disable_vblank - Disable vblank
1647  * @dp: DisplayPort IP core structure
1648  *
1649  * Disable vblank interrupt
1650  */
1651 void zynqmp_dp_disable_vblank(struct zynqmp_dp *dp)
1652 {
1653 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_VBLANK_START);
1654 }
1655 
1656 static void zynqmp_dp_hpd_work_func(struct work_struct *work)
1657 {
1658 	struct zynqmp_dp *dp = container_of(work, struct zynqmp_dp,
1659 					    hpd_work.work);
1660 	enum drm_connector_status status;
1661 
1662 	status = zynqmp_dp_bridge_detect(&dp->bridge);
1663 	drm_bridge_hpd_notify(&dp->bridge, status);
1664 }
1665 
1666 static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
1667 {
1668 	struct zynqmp_dp *dp = (struct zynqmp_dp *)data;
1669 	u32 status, mask;
1670 
1671 	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
1672 	/* clear status register as soon as we read it */
1673 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
1674 	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
1675 
1676 	/*
1677 	 * Status register may report some events, which corresponding interrupts
1678 	 * have been disabled. Filter out those events against interrupts' mask.
1679 	 */
1680 	status &= ~mask;
1681 
1682 	if (!status)
1683 		return IRQ_NONE;
1684 
1685 	/* dbg for diagnostic, but not much that the driver can do */
1686 	if (status & ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK)
1687 		dev_dbg_ratelimited(dp->dev, "underflow interrupt\n");
1688 	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
1689 		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
1690 
1691 	if (status & ZYNQMP_DP_INT_VBLANK_START)
1692 		zynqmp_dpsub_drm_handle_vblank(dp->dpsub);
1693 
1694 	if (status & ZYNQMP_DP_INT_HPD_EVENT)
1695 		schedule_delayed_work(&dp->hpd_work, 0);
1696 
1697 	if (status & ZYNQMP_DP_INT_HPD_IRQ) {
1698 		int ret;
1699 		u8 status[DP_LINK_STATUS_SIZE + 2];
1700 
1701 		ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
1702 				       DP_LINK_STATUS_SIZE + 2);
1703 		if (ret < 0)
1704 			goto handled;
1705 
1706 		if (status[4] & DP_LINK_STATUS_UPDATED ||
1707 		    !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) ||
1708 		    !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) {
1709 			zynqmp_dp_train_loop(dp);
1710 		}
1711 	}
1712 
1713 handled:
1714 	return IRQ_HANDLED;
1715 }
1716 
1717 /* -----------------------------------------------------------------------------
1718  * Initialization & Cleanup
1719  */
1720 
1721 int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub)
1722 {
1723 	struct platform_device *pdev = to_platform_device(dpsub->dev);
1724 	struct drm_bridge *bridge;
1725 	struct zynqmp_dp *dp;
1726 	struct resource *res;
1727 	int ret;
1728 
1729 	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
1730 	if (!dp)
1731 		return -ENOMEM;
1732 
1733 	dp->dev = &pdev->dev;
1734 	dp->dpsub = dpsub;
1735 	dp->status = connector_status_disconnected;
1736 
1737 	INIT_DELAYED_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func);
1738 
1739 	/* Acquire all resources (IOMEM, IRQ and PHYs). */
1740 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp");
1741 	dp->iomem = devm_ioremap_resource(dp->dev, res);
1742 	if (IS_ERR(dp->iomem)) {
1743 		ret = PTR_ERR(dp->iomem);
1744 		goto err_free;
1745 	}
1746 
1747 	dp->irq = platform_get_irq(pdev, 0);
1748 	if (dp->irq < 0) {
1749 		ret = dp->irq;
1750 		goto err_free;
1751 	}
1752 
1753 	dp->reset = devm_reset_control_get(dp->dev, NULL);
1754 	if (IS_ERR(dp->reset)) {
1755 		if (PTR_ERR(dp->reset) != -EPROBE_DEFER)
1756 			dev_err(dp->dev, "failed to get reset: %ld\n",
1757 				PTR_ERR(dp->reset));
1758 		ret = PTR_ERR(dp->reset);
1759 		goto err_free;
1760 	}
1761 
1762 	ret = zynqmp_dp_reset(dp, true);
1763 	if (ret < 0)
1764 		goto err_free;
1765 
1766 	ret = zynqmp_dp_reset(dp, false);
1767 	if (ret < 0)
1768 		goto err_free;
1769 
1770 	ret = zynqmp_dp_phy_probe(dp);
1771 	if (ret)
1772 		goto err_reset;
1773 
1774 	/* Initialize the bridge. */
1775 	bridge = &dp->bridge;
1776 	bridge->funcs = &zynqmp_dp_bridge_funcs;
1777 	bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID
1778 		    | DRM_BRIDGE_OP_HPD;
1779 	bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
1780 	bridge->of_node = dp->dev->of_node;
1781 	dpsub->bridge = bridge;
1782 
1783 	/*
1784 	 * Acquire the next bridge in the chain. Ignore errors caused by port@5
1785 	 * not being connected for backward-compatibility with older DTs.
1786 	 */
1787 	ret = drm_of_find_panel_or_bridge(dp->dev->of_node, 5, 0, NULL,
1788 					  &dp->next_bridge);
1789 	if (ret < 0 && ret != -ENODEV)
1790 		goto err_reset;
1791 
1792 	/* Initialize the hardware. */
1793 	dp->config.misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK;
1794 	zynqmp_dp_set_format(dp, NULL, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1795 
1796 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1797 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1798 	zynqmp_dp_set(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
1799 	zynqmp_dp_write(dp, ZYNQMP_DP_FORCE_SCRAMBLER_RESET, 1);
1800 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1801 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1802 
1803 	ret = zynqmp_dp_phy_init(dp);
1804 	if (ret)
1805 		goto err_reset;
1806 
1807 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1);
1808 
1809 	/*
1810 	 * Now that the hardware is initialized and won't generate spurious
1811 	 * interrupts, request the IRQ.
1812 	 */
1813 	ret = devm_request_threaded_irq(dp->dev, dp->irq, NULL,
1814 					zynqmp_dp_irq_handler, IRQF_ONESHOT,
1815 					dev_name(dp->dev), dp);
1816 	if (ret < 0)
1817 		goto err_phy_exit;
1818 
1819 	dpsub->dp = dp;
1820 
1821 	dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n",
1822 		dp->num_lanes);
1823 
1824 	return 0;
1825 
1826 err_phy_exit:
1827 	zynqmp_dp_phy_exit(dp);
1828 err_reset:
1829 	zynqmp_dp_reset(dp, true);
1830 err_free:
1831 	kfree(dp);
1832 	return ret;
1833 }
1834 
1835 void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub)
1836 {
1837 	struct zynqmp_dp *dp = dpsub->dp;
1838 
1839 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL);
1840 	disable_irq(dp->irq);
1841 
1842 	cancel_delayed_work_sync(&dp->hpd_work);
1843 
1844 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1845 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1846 
1847 	zynqmp_dp_phy_exit(dp);
1848 	zynqmp_dp_reset(dp, true);
1849 }
1850