xref: /openbmc/linux/drivers/gpu/drm/xlnx/zynqmp_dp.c (revision 7effbd18)
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/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/phy/phy.h>
29 #include <linux/reset.h>
30 #include <linux/slab.h>
31 
32 #include "zynqmp_disp.h"
33 #include "zynqmp_dp.h"
34 #include "zynqmp_dpsub.h"
35 #include "zynqmp_kms.h"
36 
37 static uint zynqmp_dp_aux_timeout_ms = 50;
38 module_param_named(aux_timeout_ms, zynqmp_dp_aux_timeout_ms, uint, 0444);
39 MODULE_PARM_DESC(aux_timeout_ms, "DP aux timeout value in msec (default: 50)");
40 
41 /*
42  * Some sink requires a delay after power on request
43  */
44 static uint zynqmp_dp_power_on_delay_ms = 4;
45 module_param_named(power_on_delay_ms, zynqmp_dp_power_on_delay_ms, uint, 0444);
46 MODULE_PARM_DESC(power_on_delay_ms, "DP power on delay in msec (default: 4)");
47 
48 /* Link configuration registers */
49 #define ZYNQMP_DP_LINK_BW_SET				0x0
50 #define ZYNQMP_DP_LANE_COUNT_SET			0x4
51 #define ZYNQMP_DP_ENHANCED_FRAME_EN			0x8
52 #define ZYNQMP_DP_TRAINING_PATTERN_SET			0xc
53 #define ZYNQMP_DP_SCRAMBLING_DISABLE			0x14
54 #define ZYNQMP_DP_DOWNSPREAD_CTL			0x18
55 #define ZYNQMP_DP_SOFTWARE_RESET			0x1c
56 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM1		BIT(0)
57 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM2		BIT(1)
58 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM3		BIT(2)
59 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM4		BIT(3)
60 #define ZYNQMP_DP_SOFTWARE_RESET_AUX			BIT(7)
61 #define ZYNQMP_DP_SOFTWARE_RESET_ALL			(ZYNQMP_DP_SOFTWARE_RESET_STREAM1 | \
62 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM2 | \
63 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM3 | \
64 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM4 | \
65 							 ZYNQMP_DP_SOFTWARE_RESET_AUX)
66 
67 /* Core enable registers */
68 #define ZYNQMP_DP_TRANSMITTER_ENABLE			0x80
69 #define ZYNQMP_DP_MAIN_STREAM_ENABLE			0x84
70 #define ZYNQMP_DP_FORCE_SCRAMBLER_RESET			0xc0
71 #define ZYNQMP_DP_VERSION				0xf8
72 #define ZYNQMP_DP_VERSION_MAJOR_MASK			GENMASK(31, 24)
73 #define ZYNQMP_DP_VERSION_MAJOR_SHIFT			24
74 #define ZYNQMP_DP_VERSION_MINOR_MASK			GENMASK(23, 16)
75 #define ZYNQMP_DP_VERSION_MINOR_SHIFT			16
76 #define ZYNQMP_DP_VERSION_REVISION_MASK			GENMASK(15, 12)
77 #define ZYNQMP_DP_VERSION_REVISION_SHIFT		12
78 #define ZYNQMP_DP_VERSION_PATCH_MASK			GENMASK(11, 8)
79 #define ZYNQMP_DP_VERSION_PATCH_SHIFT			8
80 #define ZYNQMP_DP_VERSION_INTERNAL_MASK			GENMASK(7, 0)
81 #define ZYNQMP_DP_VERSION_INTERNAL_SHIFT		0
82 
83 /* Core ID registers */
84 #define ZYNQMP_DP_CORE_ID				0xfc
85 #define ZYNQMP_DP_CORE_ID_MAJOR_MASK			GENMASK(31, 24)
86 #define ZYNQMP_DP_CORE_ID_MAJOR_SHIFT			24
87 #define ZYNQMP_DP_CORE_ID_MINOR_MASK			GENMASK(23, 16)
88 #define ZYNQMP_DP_CORE_ID_MINOR_SHIFT			16
89 #define ZYNQMP_DP_CORE_ID_REVISION_MASK			GENMASK(15, 8)
90 #define ZYNQMP_DP_CORE_ID_REVISION_SHIFT		8
91 #define ZYNQMP_DP_CORE_ID_DIRECTION			GENMASK(1)
92 
93 /* AUX channel interface registers */
94 #define ZYNQMP_DP_AUX_COMMAND				0x100
95 #define ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT			8
96 #define ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY		BIT(12)
97 #define ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT		0
98 #define ZYNQMP_DP_AUX_WRITE_FIFO			0x104
99 #define ZYNQMP_DP_AUX_ADDRESS				0x108
100 #define ZYNQMP_DP_AUX_CLK_DIVIDER			0x10c
101 #define ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT	8
102 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE		0x130
103 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD		BIT(0)
104 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST	BIT(1)
105 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY		BIT(2)
106 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT	BIT(3)
107 #define ZYNQMP_DP_AUX_REPLY_DATA			0x134
108 #define ZYNQMP_DP_AUX_REPLY_CODE			0x138
109 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK		(0)
110 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_NACK		BIT(0)
111 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_DEFER		BIT(1)
112 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK		(0)
113 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_NACK		BIT(2)
114 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_DEFER		BIT(3)
115 #define ZYNQMP_DP_AUX_REPLY_COUNT			0x13c
116 #define ZYNQMP_DP_REPLY_DATA_COUNT			0x148
117 #define ZYNQMP_DP_REPLY_DATA_COUNT_MASK			0xff
118 #define ZYNQMP_DP_INT_STATUS				0x3a0
119 #define ZYNQMP_DP_INT_MASK				0x3a4
120 #define ZYNQMP_DP_INT_EN				0x3a8
121 #define ZYNQMP_DP_INT_DS				0x3ac
122 #define ZYNQMP_DP_INT_HPD_IRQ				BIT(0)
123 #define ZYNQMP_DP_INT_HPD_EVENT				BIT(1)
124 #define ZYNQMP_DP_INT_REPLY_RECEIVED			BIT(2)
125 #define ZYNQMP_DP_INT_REPLY_TIMEOUT			BIT(3)
126 #define ZYNQMP_DP_INT_HPD_PULSE_DET			BIT(4)
127 #define ZYNQMP_DP_INT_EXT_PKT_TXD			BIT(5)
128 #define ZYNQMP_DP_INT_LIV_ABUF_UNDRFLW			BIT(12)
129 #define ZYNQMP_DP_INT_VBLANK_START			BIT(13)
130 #define ZYNQMP_DP_INT_PIXEL1_MATCH			BIT(14)
131 #define ZYNQMP_DP_INT_PIXEL0_MATCH			BIT(15)
132 #define ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK		0x3f0000
133 #define ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK		0xfc00000
134 #define ZYNQMP_DP_INT_CUST_TS_2				BIT(28)
135 #define ZYNQMP_DP_INT_CUST_TS				BIT(29)
136 #define ZYNQMP_DP_INT_EXT_VSYNC_TS			BIT(30)
137 #define ZYNQMP_DP_INT_VSYNC_TS				BIT(31)
138 #define ZYNQMP_DP_INT_ALL				(ZYNQMP_DP_INT_HPD_IRQ | \
139 							 ZYNQMP_DP_INT_HPD_EVENT | \
140 							 ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK | \
141 							 ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
142 
143 /* Main stream attribute registers */
144 #define ZYNQMP_DP_MAIN_STREAM_HTOTAL			0x180
145 #define ZYNQMP_DP_MAIN_STREAM_VTOTAL			0x184
146 #define ZYNQMP_DP_MAIN_STREAM_POLARITY			0x188
147 #define ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT	0
148 #define ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT	1
149 #define ZYNQMP_DP_MAIN_STREAM_HSWIDTH			0x18c
150 #define ZYNQMP_DP_MAIN_STREAM_VSWIDTH			0x190
151 #define ZYNQMP_DP_MAIN_STREAM_HRES			0x194
152 #define ZYNQMP_DP_MAIN_STREAM_VRES			0x198
153 #define ZYNQMP_DP_MAIN_STREAM_HSTART			0x19c
154 #define ZYNQMP_DP_MAIN_STREAM_VSTART			0x1a0
155 #define ZYNQMP_DP_MAIN_STREAM_MISC0			0x1a4
156 #define ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK		BIT(0)
157 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB	(0 << 1)
158 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422	(5 << 1)
159 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444	(6 << 1)
160 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK	(7 << 1)
161 #define ZYNQMP_DP_MAIN_STREAM_MISC0_DYNAMIC_RANGE	BIT(3)
162 #define ZYNQMP_DP_MAIN_STREAM_MISC0_YCBCR_COLR		BIT(4)
163 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6		(0 << 5)
164 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8		(1 << 5)
165 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10		(2 << 5)
166 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12		(3 << 5)
167 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16		(4 << 5)
168 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK		(7 << 5)
169 #define ZYNQMP_DP_MAIN_STREAM_MISC1			0x1a8
170 #define ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN		BIT(7)
171 #define ZYNQMP_DP_MAIN_STREAM_M_VID			0x1ac
172 #define ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE		0x1b0
173 #define ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF	64
174 #define ZYNQMP_DP_MAIN_STREAM_N_VID			0x1b4
175 #define ZYNQMP_DP_USER_PIX_WIDTH			0x1b8
176 #define ZYNQMP_DP_USER_DATA_COUNT_PER_LANE		0x1bc
177 #define ZYNQMP_DP_MIN_BYTES_PER_TU			0x1c4
178 #define ZYNQMP_DP_FRAC_BYTES_PER_TU			0x1c8
179 #define ZYNQMP_DP_INIT_WAIT				0x1cc
180 
181 /* PHY configuration and status registers */
182 #define ZYNQMP_DP_PHY_RESET				0x200
183 #define ZYNQMP_DP_PHY_RESET_PHY_RESET			BIT(0)
184 #define ZYNQMP_DP_PHY_RESET_GTTX_RESET			BIT(1)
185 #define ZYNQMP_DP_PHY_RESET_PHY_PMA_RESET		BIT(8)
186 #define ZYNQMP_DP_PHY_RESET_PHY_PCS_RESET		BIT(9)
187 #define ZYNQMP_DP_PHY_RESET_ALL_RESET			(ZYNQMP_DP_PHY_RESET_PHY_RESET | \
188 							 ZYNQMP_DP_PHY_RESET_GTTX_RESET | \
189 							 ZYNQMP_DP_PHY_RESET_PHY_PMA_RESET | \
190 							 ZYNQMP_DP_PHY_RESET_PHY_PCS_RESET)
191 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_0		0x210
192 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_1		0x214
193 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_2		0x218
194 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_3		0x21c
195 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_0		0x220
196 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_1		0x224
197 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_2		0x228
198 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_3		0x22c
199 #define ZYNQMP_DP_PHY_CLOCK_SELECT			0x234
200 #define ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G		0x1
201 #define ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G		0x3
202 #define ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G		0x5
203 #define ZYNQMP_DP_TX_PHY_POWER_DOWN			0x238
204 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_0		BIT(0)
205 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_1		BIT(1)
206 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_2		BIT(2)
207 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_3		BIT(3)
208 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL			0xf
209 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_0			0x23c
210 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_1			0x240
211 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_2			0x244
212 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_3			0x248
213 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_0			0x24c
214 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_1			0x250
215 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_2			0x254
216 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_3			0x258
217 #define ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0		0x24c
218 #define ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_1		0x250
219 #define ZYNQMP_DP_PHY_STATUS				0x280
220 #define ZYNQMP_DP_PHY_STATUS_PLL_LOCKED_SHIFT		4
221 #define ZYNQMP_DP_PHY_STATUS_FPGA_PLL_LOCKED		BIT(6)
222 
223 /* Audio registers */
224 #define ZYNQMP_DP_TX_AUDIO_CONTROL			0x300
225 #define ZYNQMP_DP_TX_AUDIO_CHANNELS			0x304
226 #define ZYNQMP_DP_TX_AUDIO_INFO_DATA			0x308
227 #define ZYNQMP_DP_TX_M_AUD				0x328
228 #define ZYNQMP_DP_TX_N_AUD				0x32c
229 #define ZYNQMP_DP_TX_AUDIO_EXT_DATA			0x330
230 
231 #define ZYNQMP_DP_MAX_LANES				2
232 #define ZYNQMP_MAX_FREQ					3000000
233 
234 #define DP_REDUCED_BIT_RATE				162000
235 #define DP_HIGH_BIT_RATE				270000
236 #define DP_HIGH_BIT_RATE2				540000
237 #define DP_MAX_TRAINING_TRIES				5
238 #define DP_V1_2						0x12
239 
240 /**
241  * struct zynqmp_dp_link_config - Common link config between source and sink
242  * @max_rate: maximum link rate
243  * @max_lanes: maximum number of lanes
244  */
245 struct zynqmp_dp_link_config {
246 	int max_rate;
247 	u8 max_lanes;
248 };
249 
250 /**
251  * struct zynqmp_dp_mode - Configured mode of DisplayPort
252  * @bw_code: code for bandwidth(link rate)
253  * @lane_cnt: number of lanes
254  * @pclock: pixel clock frequency of current mode
255  * @fmt: format identifier string
256  */
257 struct zynqmp_dp_mode {
258 	u8 bw_code;
259 	u8 lane_cnt;
260 	int pclock;
261 	const char *fmt;
262 };
263 
264 /**
265  * struct zynqmp_dp_config - Configuration of DisplayPort from DTS
266  * @misc0: misc0 configuration (per DP v1.2 spec)
267  * @misc1: misc1 configuration (per DP v1.2 spec)
268  * @bpp: bits per pixel
269  */
270 struct zynqmp_dp_config {
271 	u8 misc0;
272 	u8 misc1;
273 	u8 bpp;
274 };
275 
276 /**
277  * struct zynqmp_dp - Xilinx DisplayPort core
278  * @dev: device structure
279  * @dpsub: Display subsystem
280  * @iomem: device I/O memory for register access
281  * @reset: reset controller
282  * @irq: irq
283  * @bridge: DRM bridge for the DP encoder
284  * @next_bridge: The downstream bridge
285  * @config: IP core configuration from DTS
286  * @aux: aux channel
287  * @phy: PHY handles for DP lanes
288  * @num_lanes: number of enabled phy lanes
289  * @hpd_work: hot plug detection worker
290  * @status: connection status
291  * @enabled: flag to indicate if the device is enabled
292  * @dpcd: DP configuration data from currently connected sink device
293  * @link_config: common link configuration between IP core and sink device
294  * @mode: current mode between IP core and sink device
295  * @train_set: set of training data
296  */
297 struct zynqmp_dp {
298 	struct device *dev;
299 	struct zynqmp_dpsub *dpsub;
300 	void __iomem *iomem;
301 	struct reset_control *reset;
302 	int irq;
303 
304 	struct drm_bridge bridge;
305 	struct drm_bridge *next_bridge;
306 
307 	struct zynqmp_dp_config config;
308 	struct drm_dp_aux aux;
309 	struct phy *phy[ZYNQMP_DP_MAX_LANES];
310 	u8 num_lanes;
311 	struct delayed_work hpd_work;
312 	enum drm_connector_status status;
313 	bool enabled;
314 
315 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
316 	struct zynqmp_dp_link_config link_config;
317 	struct zynqmp_dp_mode mode;
318 	u8 train_set[ZYNQMP_DP_MAX_LANES];
319 };
320 
321 static inline struct zynqmp_dp *bridge_to_dp(struct drm_bridge *bridge)
322 {
323 	return container_of(bridge, struct zynqmp_dp, bridge);
324 }
325 
326 static void zynqmp_dp_write(struct zynqmp_dp *dp, int offset, u32 val)
327 {
328 	writel(val, dp->iomem + offset);
329 }
330 
331 static u32 zynqmp_dp_read(struct zynqmp_dp *dp, int offset)
332 {
333 	return readl(dp->iomem + offset);
334 }
335 
336 static void zynqmp_dp_clr(struct zynqmp_dp *dp, int offset, u32 clr)
337 {
338 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) & ~clr);
339 }
340 
341 static void zynqmp_dp_set(struct zynqmp_dp *dp, int offset, u32 set)
342 {
343 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) | set);
344 }
345 
346 /* -----------------------------------------------------------------------------
347  * PHY Handling
348  */
349 
350 #define RST_TIMEOUT_MS			1000
351 
352 static int zynqmp_dp_reset(struct zynqmp_dp *dp, bool assert)
353 {
354 	unsigned long timeout;
355 
356 	if (assert)
357 		reset_control_assert(dp->reset);
358 	else
359 		reset_control_deassert(dp->reset);
360 
361 	/* Wait for the (de)assert to complete. */
362 	timeout = jiffies + msecs_to_jiffies(RST_TIMEOUT_MS);
363 	while (!time_after_eq(jiffies, timeout)) {
364 		bool status = !!reset_control_status(dp->reset);
365 
366 		if (assert == status)
367 			return 0;
368 
369 		cpu_relax();
370 	}
371 
372 	dev_err(dp->dev, "reset %s timeout\n", assert ? "assert" : "deassert");
373 	return -ETIMEDOUT;
374 }
375 
376 /**
377  * zynqmp_dp_phy_init - Initialize the phy
378  * @dp: DisplayPort IP core structure
379  *
380  * Initialize the phy.
381  *
382  * Return: 0 if the phy instances are initialized correctly, or the error code
383  * returned from the callee functions.
384  */
385 static int zynqmp_dp_phy_init(struct zynqmp_dp *dp)
386 {
387 	int ret;
388 	int i;
389 
390 	for (i = 0; i < dp->num_lanes; i++) {
391 		ret = phy_init(dp->phy[i]);
392 		if (ret) {
393 			dev_err(dp->dev, "failed to init phy lane %d\n", i);
394 			return ret;
395 		}
396 	}
397 
398 	zynqmp_dp_clr(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
399 
400 	/*
401 	 * Power on lanes in reverse order as only lane 0 waits for the PLL to
402 	 * lock.
403 	 */
404 	for (i = dp->num_lanes - 1; i >= 0; i--) {
405 		ret = phy_power_on(dp->phy[i]);
406 		if (ret) {
407 			dev_err(dp->dev, "failed to power on phy lane %d\n", i);
408 			return ret;
409 		}
410 	}
411 
412 	return 0;
413 }
414 
415 /**
416  * zynqmp_dp_phy_exit - Exit the phy
417  * @dp: DisplayPort IP core structure
418  *
419  * Exit the phy.
420  */
421 static void zynqmp_dp_phy_exit(struct zynqmp_dp *dp)
422 {
423 	unsigned int i;
424 	int ret;
425 
426 	for (i = 0; i < dp->num_lanes; i++) {
427 		ret = phy_power_off(dp->phy[i]);
428 		if (ret)
429 			dev_err(dp->dev, "failed to power off phy(%d) %d\n", i,
430 				ret);
431 	}
432 
433 	for (i = 0; i < dp->num_lanes; i++) {
434 		ret = phy_exit(dp->phy[i]);
435 		if (ret)
436 			dev_err(dp->dev, "failed to exit phy(%d) %d\n", i, ret);
437 	}
438 }
439 
440 /**
441  * zynqmp_dp_phy_probe - Probe the PHYs
442  * @dp: DisplayPort IP core structure
443  *
444  * Probe PHYs for all lanes. Less PHYs may be available than the number of
445  * lanes, which is not considered an error as long as at least one PHY is
446  * found. The caller can check dp->num_lanes to check how many PHYs were found.
447  *
448  * Return:
449  * * 0				- Success
450  * * -ENXIO			- No PHY found
451  * * -EPROBE_DEFER		- Probe deferral requested
452  * * Other negative value	- PHY retrieval failure
453  */
454 static int zynqmp_dp_phy_probe(struct zynqmp_dp *dp)
455 {
456 	unsigned int i;
457 
458 	for (i = 0; i < ZYNQMP_DP_MAX_LANES; i++) {
459 		char phy_name[16];
460 		struct phy *phy;
461 
462 		snprintf(phy_name, sizeof(phy_name), "dp-phy%d", i);
463 		phy = devm_phy_get(dp->dev, phy_name);
464 
465 		if (IS_ERR(phy)) {
466 			switch (PTR_ERR(phy)) {
467 			case -ENODEV:
468 				if (dp->num_lanes)
469 					return 0;
470 
471 				dev_err(dp->dev, "no PHY found\n");
472 				return -ENXIO;
473 
474 			case -EPROBE_DEFER:
475 				return -EPROBE_DEFER;
476 
477 			default:
478 				dev_err(dp->dev, "failed to get PHY lane %u\n",
479 					i);
480 				return PTR_ERR(phy);
481 			}
482 		}
483 
484 		dp->phy[i] = phy;
485 		dp->num_lanes++;
486 	}
487 
488 	return 0;
489 }
490 
491 /**
492  * zynqmp_dp_phy_ready - Check if PHY is ready
493  * @dp: DisplayPort IP core structure
494  *
495  * Check if PHY is ready. If PHY is not ready, wait 1ms to check for 100 times.
496  * This amount of delay was suggested by IP designer.
497  *
498  * Return: 0 if PHY is ready, or -ENODEV if PHY is not ready.
499  */
500 static int zynqmp_dp_phy_ready(struct zynqmp_dp *dp)
501 {
502 	u32 i, reg, ready;
503 
504 	ready = (1 << dp->num_lanes) - 1;
505 
506 	/* Wait for 100 * 1ms. This should be enough time for PHY to be ready */
507 	for (i = 0; ; i++) {
508 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_PHY_STATUS);
509 		if ((reg & ready) == ready)
510 			return 0;
511 
512 		if (i == 100) {
513 			dev_err(dp->dev, "PHY isn't ready\n");
514 			return -ENODEV;
515 		}
516 
517 		usleep_range(1000, 1100);
518 	}
519 
520 	return 0;
521 }
522 
523 /* -----------------------------------------------------------------------------
524  * DisplayPort Link Training
525  */
526 
527 /**
528  * zynqmp_dp_max_rate - Calculate and return available max pixel clock
529  * @link_rate: link rate (Kilo-bytes / sec)
530  * @lane_num: number of lanes
531  * @bpp: bits per pixel
532  *
533  * Return: max pixel clock (KHz) supported by current link config.
534  */
535 static inline int zynqmp_dp_max_rate(int link_rate, u8 lane_num, u8 bpp)
536 {
537 	return link_rate * lane_num * 8 / bpp;
538 }
539 
540 /**
541  * zynqmp_dp_mode_configure - Configure the link values
542  * @dp: DisplayPort IP core structure
543  * @pclock: pixel clock for requested display mode
544  * @current_bw: current link rate
545  *
546  * Find the link configuration values, rate and lane count for requested pixel
547  * clock @pclock. The @pclock is stored in the mode to be used in other
548  * functions later. The returned rate is downshifted from the current rate
549  * @current_bw.
550  *
551  * Return: Current link rate code, or -EINVAL.
552  */
553 static int zynqmp_dp_mode_configure(struct zynqmp_dp *dp, int pclock,
554 				    u8 current_bw)
555 {
556 	int max_rate = dp->link_config.max_rate;
557 	u8 bw_code;
558 	u8 max_lanes = dp->link_config.max_lanes;
559 	u8 max_link_rate_code = drm_dp_link_rate_to_bw_code(max_rate);
560 	u8 bpp = dp->config.bpp;
561 	u8 lane_cnt;
562 
563 	/* Downshift from current bandwidth */
564 	switch (current_bw) {
565 	case DP_LINK_BW_5_4:
566 		bw_code = DP_LINK_BW_2_7;
567 		break;
568 	case DP_LINK_BW_2_7:
569 		bw_code = DP_LINK_BW_1_62;
570 		break;
571 	case DP_LINK_BW_1_62:
572 		dev_err(dp->dev, "can't downshift. already lowest link rate\n");
573 		return -EINVAL;
574 	default:
575 		/* If not given, start with max supported */
576 		bw_code = max_link_rate_code;
577 		break;
578 	}
579 
580 	for (lane_cnt = 1; lane_cnt <= max_lanes; lane_cnt <<= 1) {
581 		int bw;
582 		u32 rate;
583 
584 		bw = drm_dp_bw_code_to_link_rate(bw_code);
585 		rate = zynqmp_dp_max_rate(bw, lane_cnt, bpp);
586 		if (pclock <= rate) {
587 			dp->mode.bw_code = bw_code;
588 			dp->mode.lane_cnt = lane_cnt;
589 			dp->mode.pclock = pclock;
590 			return dp->mode.bw_code;
591 		}
592 	}
593 
594 	dev_err(dp->dev, "failed to configure link values\n");
595 
596 	return -EINVAL;
597 }
598 
599 /**
600  * zynqmp_dp_adjust_train - Adjust train values
601  * @dp: DisplayPort IP core structure
602  * @link_status: link status from sink which contains requested training values
603  */
604 static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp,
605 				   u8 link_status[DP_LINK_STATUS_SIZE])
606 {
607 	u8 *train_set = dp->train_set;
608 	u8 voltage = 0, preemphasis = 0;
609 	u8 i;
610 
611 	for (i = 0; i < dp->mode.lane_cnt; i++) {
612 		u8 v = drm_dp_get_adjust_request_voltage(link_status, i);
613 		u8 p = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
614 
615 		if (v > voltage)
616 			voltage = v;
617 
618 		if (p > preemphasis)
619 			preemphasis = p;
620 	}
621 
622 	if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3)
623 		voltage |= DP_TRAIN_MAX_SWING_REACHED;
624 
625 	if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2)
626 		preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
627 
628 	for (i = 0; i < dp->mode.lane_cnt; i++)
629 		train_set[i] = voltage | preemphasis;
630 }
631 
632 /**
633  * zynqmp_dp_update_vs_emph - Update the training values
634  * @dp: DisplayPort IP core structure
635  *
636  * Update the training values based on the request from sink. The mapped values
637  * are predefined, and values(vs, pe, pc) are from the device manual.
638  *
639  * Return: 0 if vs and emph are updated successfully, or the error code returned
640  * by drm_dp_dpcd_write().
641  */
642 static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
643 {
644 	unsigned int i;
645 	int ret;
646 
647 	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->train_set,
648 				dp->mode.lane_cnt);
649 	if (ret < 0)
650 		return ret;
651 
652 	for (i = 0; i < dp->mode.lane_cnt; i++) {
653 		u32 reg = ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0 + i * 4;
654 		union phy_configure_opts opts = { 0 };
655 		u8 train = dp->train_set[i];
656 
657 		opts.dp.voltage[0] = (train & DP_TRAIN_VOLTAGE_SWING_MASK)
658 				   >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
659 		opts.dp.pre[0] = (train & DP_TRAIN_PRE_EMPHASIS_MASK)
660 			       >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
661 
662 		phy_configure(dp->phy[i], &opts);
663 
664 		zynqmp_dp_write(dp, reg, 0x2);
665 	}
666 
667 	return 0;
668 }
669 
670 /**
671  * zynqmp_dp_link_train_cr - Train clock recovery
672  * @dp: DisplayPort IP core structure
673  *
674  * Return: 0 if clock recovery train is done successfully, or corresponding
675  * error code.
676  */
677 static int zynqmp_dp_link_train_cr(struct zynqmp_dp *dp)
678 {
679 	u8 link_status[DP_LINK_STATUS_SIZE];
680 	u8 lane_cnt = dp->mode.lane_cnt;
681 	u8 vs = 0, tries = 0;
682 	u16 max_tries, i;
683 	bool cr_done;
684 	int ret;
685 
686 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
687 			DP_TRAINING_PATTERN_1);
688 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
689 				 DP_TRAINING_PATTERN_1 |
690 				 DP_LINK_SCRAMBLING_DISABLE);
691 	if (ret < 0)
692 		return ret;
693 
694 	/*
695 	 * 256 loops should be maximum iterations for 4 lanes and 4 values.
696 	 * So, This loop should exit before 512 iterations
697 	 */
698 	for (max_tries = 0; max_tries < 512; max_tries++) {
699 		ret = zynqmp_dp_update_vs_emph(dp);
700 		if (ret)
701 			return ret;
702 
703 		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
704 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
705 		if (ret < 0)
706 			return ret;
707 
708 		cr_done = drm_dp_clock_recovery_ok(link_status, lane_cnt);
709 		if (cr_done)
710 			break;
711 
712 		for (i = 0; i < lane_cnt; i++)
713 			if (!(dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED))
714 				break;
715 		if (i == lane_cnt)
716 			break;
717 
718 		if ((dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == vs)
719 			tries++;
720 		else
721 			tries = 0;
722 
723 		if (tries == DP_MAX_TRAINING_TRIES)
724 			break;
725 
726 		vs = dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
727 		zynqmp_dp_adjust_train(dp, link_status);
728 	}
729 
730 	if (!cr_done)
731 		return -EIO;
732 
733 	return 0;
734 }
735 
736 /**
737  * zynqmp_dp_link_train_ce - Train channel equalization
738  * @dp: DisplayPort IP core structure
739  *
740  * Return: 0 if channel equalization train is done successfully, or
741  * corresponding error code.
742  */
743 static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
744 {
745 	u8 link_status[DP_LINK_STATUS_SIZE];
746 	u8 lane_cnt = dp->mode.lane_cnt;
747 	u32 pat, tries;
748 	int ret;
749 	bool ce_done;
750 
751 	if (dp->dpcd[DP_DPCD_REV] >= DP_V1_2 &&
752 	    dp->dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED)
753 		pat = DP_TRAINING_PATTERN_3;
754 	else
755 		pat = DP_TRAINING_PATTERN_2;
756 
757 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET, pat);
758 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
759 				 pat | DP_LINK_SCRAMBLING_DISABLE);
760 	if (ret < 0)
761 		return ret;
762 
763 	for (tries = 0; tries < DP_MAX_TRAINING_TRIES; tries++) {
764 		ret = zynqmp_dp_update_vs_emph(dp);
765 		if (ret)
766 			return ret;
767 
768 		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
769 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
770 		if (ret < 0)
771 			return ret;
772 
773 		ce_done = drm_dp_channel_eq_ok(link_status, lane_cnt);
774 		if (ce_done)
775 			break;
776 
777 		zynqmp_dp_adjust_train(dp, link_status);
778 	}
779 
780 	if (!ce_done)
781 		return -EIO;
782 
783 	return 0;
784 }
785 
786 /**
787  * zynqmp_dp_link_train - Train the link
788  * @dp: DisplayPort IP core structure
789  *
790  * Return: 0 if all trains are done successfully, or corresponding error code.
791  */
792 static int zynqmp_dp_train(struct zynqmp_dp *dp)
793 {
794 	u32 reg;
795 	u8 bw_code = dp->mode.bw_code;
796 	u8 lane_cnt = dp->mode.lane_cnt;
797 	u8 aux_lane_cnt = lane_cnt;
798 	bool enhanced;
799 	int ret;
800 
801 	zynqmp_dp_write(dp, ZYNQMP_DP_LANE_COUNT_SET, lane_cnt);
802 	enhanced = drm_dp_enhanced_frame_cap(dp->dpcd);
803 	if (enhanced) {
804 		zynqmp_dp_write(dp, ZYNQMP_DP_ENHANCED_FRAME_EN, 1);
805 		aux_lane_cnt |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
806 	}
807 
808 	if (dp->dpcd[3] & 0x1) {
809 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 1);
810 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL,
811 				   DP_SPREAD_AMP_0_5);
812 	} else {
813 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 0);
814 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL, 0);
815 	}
816 
817 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET, aux_lane_cnt);
818 	if (ret < 0) {
819 		dev_err(dp->dev, "failed to set lane count\n");
820 		return ret;
821 	}
822 
823 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
824 				 DP_SET_ANSI_8B10B);
825 	if (ret < 0) {
826 		dev_err(dp->dev, "failed to set ANSI 8B/10B encoding\n");
827 		return ret;
828 	}
829 
830 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LINK_BW_SET, bw_code);
831 	if (ret < 0) {
832 		dev_err(dp->dev, "failed to set DP bandwidth\n");
833 		return ret;
834 	}
835 
836 	zynqmp_dp_write(dp, ZYNQMP_DP_LINK_BW_SET, bw_code);
837 	switch (bw_code) {
838 	case DP_LINK_BW_1_62:
839 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G;
840 		break;
841 	case DP_LINK_BW_2_7:
842 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G;
843 		break;
844 	case DP_LINK_BW_5_4:
845 	default:
846 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G;
847 		break;
848 	}
849 
850 	zynqmp_dp_write(dp, ZYNQMP_DP_PHY_CLOCK_SELECT, reg);
851 	ret = zynqmp_dp_phy_ready(dp);
852 	if (ret < 0)
853 		return ret;
854 
855 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 1);
856 	memset(dp->train_set, 0, sizeof(dp->train_set));
857 	ret = zynqmp_dp_link_train_cr(dp);
858 	if (ret)
859 		return ret;
860 
861 	ret = zynqmp_dp_link_train_ce(dp);
862 	if (ret)
863 		return ret;
864 
865 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
866 				 DP_TRAINING_PATTERN_DISABLE);
867 	if (ret < 0) {
868 		dev_err(dp->dev, "failed to disable training pattern\n");
869 		return ret;
870 	}
871 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
872 			DP_TRAINING_PATTERN_DISABLE);
873 
874 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 0);
875 
876 	return 0;
877 }
878 
879 /**
880  * zynqmp_dp_train_loop - Downshift the link rate during training
881  * @dp: DisplayPort IP core structure
882  *
883  * Train the link by downshifting the link rate if training is not successful.
884  */
885 static void zynqmp_dp_train_loop(struct zynqmp_dp *dp)
886 {
887 	struct zynqmp_dp_mode *mode = &dp->mode;
888 	u8 bw = mode->bw_code;
889 	int ret;
890 
891 	do {
892 		if (dp->status == connector_status_disconnected ||
893 		    !dp->enabled)
894 			return;
895 
896 		ret = zynqmp_dp_train(dp);
897 		if (!ret)
898 			return;
899 
900 		ret = zynqmp_dp_mode_configure(dp, mode->pclock, bw);
901 		if (ret < 0)
902 			goto err_out;
903 
904 		bw = ret;
905 	} while (bw >= DP_LINK_BW_1_62);
906 
907 err_out:
908 	dev_err(dp->dev, "failed to train the DP link\n");
909 }
910 
911 /* -----------------------------------------------------------------------------
912  * DisplayPort AUX
913  */
914 
915 #define AUX_READ_BIT	0x1
916 
917 /**
918  * zynqmp_dp_aux_cmd_submit - Submit aux command
919  * @dp: DisplayPort IP core structure
920  * @cmd: aux command
921  * @addr: aux address
922  * @buf: buffer for command data
923  * @bytes: number of bytes for @buf
924  * @reply: reply code to be returned
925  *
926  * Submit an aux command. All aux related commands, native or i2c aux
927  * read/write, are submitted through this function. The function is mapped to
928  * the transfer function of struct drm_dp_aux. This function involves in
929  * multiple register reads/writes, thus synchronization is needed, and it is
930  * done by drm_dp_helper using @hw_mutex. The calling thread goes into sleep
931  * if there's no immediate reply to the command submission. The reply code is
932  * returned at @reply if @reply != NULL.
933  *
934  * Return: 0 if the command is submitted properly, or corresponding error code:
935  * -EBUSY when there is any request already being processed
936  * -ETIMEDOUT when receiving reply is timed out
937  * -EIO when received bytes are less than requested
938  */
939 static int zynqmp_dp_aux_cmd_submit(struct zynqmp_dp *dp, u32 cmd, u16 addr,
940 				    u8 *buf, u8 bytes, u8 *reply)
941 {
942 	bool is_read = (cmd & AUX_READ_BIT) ? true : false;
943 	u32 reg, i;
944 
945 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
946 	if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST)
947 		return -EBUSY;
948 
949 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_ADDRESS, addr);
950 	if (!is_read)
951 		for (i = 0; i < bytes; i++)
952 			zynqmp_dp_write(dp, ZYNQMP_DP_AUX_WRITE_FIFO,
953 					buf[i]);
954 
955 	reg = cmd << ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT;
956 	if (!buf || !bytes)
957 		reg |= ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY;
958 	else
959 		reg |= (bytes - 1) << ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT;
960 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_COMMAND, reg);
961 
962 	/* Wait for reply to be delivered upto 2ms */
963 	for (i = 0; ; i++) {
964 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
965 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY)
966 			break;
967 
968 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT ||
969 		    i == 2)
970 			return -ETIMEDOUT;
971 
972 		usleep_range(1000, 1100);
973 	}
974 
975 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_CODE);
976 	if (reply)
977 		*reply = reg;
978 
979 	if (is_read &&
980 	    (reg == ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK ||
981 	     reg == ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK)) {
982 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_REPLY_DATA_COUNT);
983 		if ((reg & ZYNQMP_DP_REPLY_DATA_COUNT_MASK) != bytes)
984 			return -EIO;
985 
986 		for (i = 0; i < bytes; i++)
987 			buf[i] = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_DATA);
988 	}
989 
990 	return 0;
991 }
992 
993 static ssize_t
994 zynqmp_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
995 {
996 	struct zynqmp_dp *dp = container_of(aux, struct zynqmp_dp, aux);
997 	int ret;
998 	unsigned int i, iter;
999 
1000 	/* Number of loops = timeout in msec / aux delay (400 usec) */
1001 	iter = zynqmp_dp_aux_timeout_ms * 1000 / 400;
1002 	iter = iter ? iter : 1;
1003 
1004 	for (i = 0; i < iter; i++) {
1005 		ret = zynqmp_dp_aux_cmd_submit(dp, msg->request, msg->address,
1006 					       msg->buffer, msg->size,
1007 					       &msg->reply);
1008 		if (!ret) {
1009 			dev_dbg(dp->dev, "aux %d retries\n", i);
1010 			return msg->size;
1011 		}
1012 
1013 		if (dp->status == connector_status_disconnected) {
1014 			dev_dbg(dp->dev, "no connected aux device\n");
1015 			return -ENODEV;
1016 		}
1017 
1018 		usleep_range(400, 500);
1019 	}
1020 
1021 	dev_dbg(dp->dev, "failed to do aux transfer (%d)\n", ret);
1022 
1023 	return ret;
1024 }
1025 
1026 /**
1027  * zynqmp_dp_aux_init - Initialize and register the DP AUX
1028  * @dp: DisplayPort IP core structure
1029  *
1030  * Program the AUX clock divider and filter and register the DP AUX adapter.
1031  *
1032  * Return: 0 on success, error value otherwise
1033  */
1034 static int zynqmp_dp_aux_init(struct zynqmp_dp *dp)
1035 {
1036 	unsigned long rate;
1037 	unsigned int w;
1038 
1039 	/*
1040 	 * The AUX_SIGNAL_WIDTH_FILTER is the number of APB clock cycles
1041 	 * corresponding to the AUX pulse. Allowable values are 8, 16, 24, 32,
1042 	 * 40 and 48. The AUX pulse width must be between 0.4µs and 0.6µs,
1043 	 * compute the w / 8 value corresponding to 0.4µs rounded up, and make
1044 	 * sure it stays below 0.6µs and within the allowable values.
1045 	 */
1046 	rate = clk_get_rate(dp->dpsub->apb_clk);
1047 	w = DIV_ROUND_UP(4 * rate, 1000 * 1000 * 10 * 8) * 8;
1048 	if (w > 6 * rate / (1000 * 1000 * 10) || w > 48) {
1049 		dev_err(dp->dev, "aclk frequency too high\n");
1050 		return -EINVAL;
1051 	}
1052 
1053 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_CLK_DIVIDER,
1054 			(w << ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT) |
1055 			(rate / (1000 * 1000)));
1056 
1057 	dp->aux.name = "ZynqMP DP AUX";
1058 	dp->aux.dev = dp->dev;
1059 	dp->aux.drm_dev = dp->bridge.dev;
1060 	dp->aux.transfer = zynqmp_dp_aux_transfer;
1061 
1062 	return drm_dp_aux_register(&dp->aux);
1063 }
1064 
1065 /**
1066  * zynqmp_dp_aux_cleanup - Cleanup the DP AUX
1067  * @dp: DisplayPort IP core structure
1068  *
1069  * Unregister the DP AUX adapter.
1070  */
1071 static void zynqmp_dp_aux_cleanup(struct zynqmp_dp *dp)
1072 {
1073 	drm_dp_aux_unregister(&dp->aux);
1074 }
1075 
1076 /* -----------------------------------------------------------------------------
1077  * DisplayPort Generic Support
1078  */
1079 
1080 /**
1081  * zynqmp_dp_update_misc - Write the misc registers
1082  * @dp: DisplayPort IP core structure
1083  *
1084  * The misc register values are stored in the structure, and this
1085  * function applies the values into the registers.
1086  */
1087 static void zynqmp_dp_update_misc(struct zynqmp_dp *dp)
1088 {
1089 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC0, dp->config.misc0);
1090 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC1, dp->config.misc1);
1091 }
1092 
1093 /**
1094  * zynqmp_dp_set_format - Set the input format
1095  * @dp: DisplayPort IP core structure
1096  * @info: Display info
1097  * @format: input format
1098  * @bpc: bits per component
1099  *
1100  * Update misc register values based on input @format and @bpc.
1101  *
1102  * Return: 0 on success, or -EINVAL.
1103  */
1104 static int zynqmp_dp_set_format(struct zynqmp_dp *dp,
1105 				const struct drm_display_info *info,
1106 				enum zynqmp_dpsub_format format,
1107 				unsigned int bpc)
1108 {
1109 	struct zynqmp_dp_config *config = &dp->config;
1110 	unsigned int num_colors;
1111 
1112 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK;
1113 	config->misc1 &= ~ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1114 
1115 	switch (format) {
1116 	case ZYNQMP_DPSUB_FORMAT_RGB:
1117 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB;
1118 		num_colors = 3;
1119 		break;
1120 
1121 	case ZYNQMP_DPSUB_FORMAT_YCRCB444:
1122 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444;
1123 		num_colors = 3;
1124 		break;
1125 
1126 	case ZYNQMP_DPSUB_FORMAT_YCRCB422:
1127 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422;
1128 		num_colors = 2;
1129 		break;
1130 
1131 	case ZYNQMP_DPSUB_FORMAT_YONLY:
1132 		config->misc1 |= ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1133 		num_colors = 1;
1134 		break;
1135 
1136 	default:
1137 		dev_err(dp->dev, "Invalid colormetry in DT\n");
1138 		return -EINVAL;
1139 	}
1140 
1141 	if (info && info->bpc && bpc > info->bpc) {
1142 		dev_warn(dp->dev,
1143 			 "downgrading requested %ubpc to display limit %ubpc\n",
1144 			 bpc, info->bpc);
1145 		bpc = info->bpc;
1146 	}
1147 
1148 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK;
1149 
1150 	switch (bpc) {
1151 	case 6:
1152 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6;
1153 		break;
1154 	case 8:
1155 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1156 		break;
1157 	case 10:
1158 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10;
1159 		break;
1160 	case 12:
1161 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12;
1162 		break;
1163 	case 16:
1164 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16;
1165 		break;
1166 	default:
1167 		dev_warn(dp->dev, "Not supported bpc (%u). fall back to 8bpc\n",
1168 			 bpc);
1169 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1170 		bpc = 8;
1171 		break;
1172 	}
1173 
1174 	/* Update the current bpp based on the format. */
1175 	config->bpp = bpc * num_colors;
1176 
1177 	return 0;
1178 }
1179 
1180 /**
1181  * zynqmp_dp_encoder_mode_set_transfer_unit - Set the transfer unit values
1182  * @dp: DisplayPort IP core structure
1183  * @mode: requested display mode
1184  *
1185  * Set the transfer unit, and calculate all transfer unit size related values.
1186  * Calculation is based on DP and IP core specification.
1187  */
1188 static void
1189 zynqmp_dp_encoder_mode_set_transfer_unit(struct zynqmp_dp *dp,
1190 					 const struct drm_display_mode *mode)
1191 {
1192 	u32 tu = ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF;
1193 	u32 bw, vid_kbytes, avg_bytes_per_tu, init_wait;
1194 
1195 	/* Use the max transfer unit size (default) */
1196 	zynqmp_dp_write(dp, ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE, tu);
1197 
1198 	vid_kbytes = mode->clock * (dp->config.bpp / 8);
1199 	bw = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1200 	avg_bytes_per_tu = vid_kbytes * tu / (dp->mode.lane_cnt * bw / 1000);
1201 	zynqmp_dp_write(dp, ZYNQMP_DP_MIN_BYTES_PER_TU,
1202 			avg_bytes_per_tu / 1000);
1203 	zynqmp_dp_write(dp, ZYNQMP_DP_FRAC_BYTES_PER_TU,
1204 			avg_bytes_per_tu % 1000);
1205 
1206 	/* Configure the initial wait cycle based on transfer unit size */
1207 	if (tu < (avg_bytes_per_tu / 1000))
1208 		init_wait = 0;
1209 	else if ((avg_bytes_per_tu / 1000) <= 4)
1210 		init_wait = tu;
1211 	else
1212 		init_wait = tu - avg_bytes_per_tu / 1000;
1213 
1214 	zynqmp_dp_write(dp, ZYNQMP_DP_INIT_WAIT, init_wait);
1215 }
1216 
1217 /**
1218  * zynqmp_dp_encoder_mode_set_stream - Configure the main stream
1219  * @dp: DisplayPort IP core structure
1220  * @mode: requested display mode
1221  *
1222  * Configure the main stream based on the requested mode @mode. Calculation is
1223  * based on IP core specification.
1224  */
1225 static void zynqmp_dp_encoder_mode_set_stream(struct zynqmp_dp *dp,
1226 					      const struct drm_display_mode *mode)
1227 {
1228 	u8 lane_cnt = dp->mode.lane_cnt;
1229 	u32 reg, wpl;
1230 	unsigned int rate;
1231 
1232 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HTOTAL, mode->htotal);
1233 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VTOTAL, mode->vtotal);
1234 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_POLARITY,
1235 			(!!(mode->flags & DRM_MODE_FLAG_PVSYNC) <<
1236 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT) |
1237 			(!!(mode->flags & DRM_MODE_FLAG_PHSYNC) <<
1238 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT));
1239 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSWIDTH,
1240 			mode->hsync_end - mode->hsync_start);
1241 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSWIDTH,
1242 			mode->vsync_end - mode->vsync_start);
1243 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HRES, mode->hdisplay);
1244 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VRES, mode->vdisplay);
1245 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSTART,
1246 			mode->htotal - mode->hsync_start);
1247 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSTART,
1248 			mode->vtotal - mode->vsync_start);
1249 
1250 	/* In synchronous mode, set the dividers */
1251 	if (dp->config.misc0 & ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK) {
1252 		reg = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1253 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_N_VID, reg);
1254 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_M_VID, mode->clock);
1255 		rate = zynqmp_dpsub_get_audio_clk_rate(dp->dpsub);
1256 		if (rate) {
1257 			dev_dbg(dp->dev, "Audio rate: %d\n", rate / 512);
1258 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_N_AUD, reg);
1259 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_M_AUD, rate / 1000);
1260 		}
1261 	}
1262 
1263 	/* Only 2 channel audio is supported now */
1264 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1265 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CHANNELS, 1);
1266 
1267 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_PIX_WIDTH, 1);
1268 
1269 	/* Translate to the native 16 bit datapath based on IP core spec */
1270 	wpl = (mode->hdisplay * dp->config.bpp + 15) / 16;
1271 	reg = wpl + wpl % lane_cnt - lane_cnt;
1272 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_DATA_COUNT_PER_LANE, reg);
1273 }
1274 
1275 /* -----------------------------------------------------------------------------
1276  * DISP Configuration
1277  */
1278 
1279 static void zynqmp_dp_disp_enable(struct zynqmp_dp *dp,
1280 				  struct drm_bridge_state *old_bridge_state)
1281 {
1282 	enum zynqmp_dpsub_layer_id layer_id;
1283 	struct zynqmp_disp_layer *layer;
1284 	const struct drm_format_info *info;
1285 
1286 	if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO))
1287 		layer_id = ZYNQMP_DPSUB_LAYER_VID;
1288 	else if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))
1289 		layer_id = ZYNQMP_DPSUB_LAYER_GFX;
1290 	else
1291 		return;
1292 
1293 	layer = dp->dpsub->layers[layer_id];
1294 
1295 	/* TODO: Make the format configurable. */
1296 	info = drm_format_info(DRM_FORMAT_YUV422);
1297 	zynqmp_disp_layer_set_format(layer, info);
1298 	zynqmp_disp_layer_enable(layer, ZYNQMP_DPSUB_LAYER_LIVE);
1299 
1300 	if (layer_id == ZYNQMP_DPSUB_LAYER_GFX)
1301 		zynqmp_disp_blend_set_global_alpha(dp->dpsub->disp, true, 255);
1302 	else
1303 		zynqmp_disp_blend_set_global_alpha(dp->dpsub->disp, false, 0);
1304 
1305 	zynqmp_disp_enable(dp->dpsub->disp);
1306 }
1307 
1308 static void zynqmp_dp_disp_disable(struct zynqmp_dp *dp,
1309 				   struct drm_bridge_state *old_bridge_state)
1310 {
1311 	struct zynqmp_disp_layer *layer;
1312 
1313 	if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO))
1314 		layer = dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_VID];
1315 	else if (dp->dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))
1316 		layer = dp->dpsub->layers[ZYNQMP_DPSUB_LAYER_GFX];
1317 	else
1318 		return;
1319 
1320 	zynqmp_disp_disable(dp->dpsub->disp);
1321 	zynqmp_disp_layer_disable(layer);
1322 }
1323 
1324 /* -----------------------------------------------------------------------------
1325  * DRM Bridge
1326  */
1327 
1328 static int zynqmp_dp_bridge_attach(struct drm_bridge *bridge,
1329 				   enum drm_bridge_attach_flags flags)
1330 {
1331 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1332 	int ret;
1333 
1334 	/* Initialize and register the AUX adapter. */
1335 	ret = zynqmp_dp_aux_init(dp);
1336 	if (ret) {
1337 		dev_err(dp->dev, "failed to initialize DP aux\n");
1338 		return ret;
1339 	}
1340 
1341 	if (dp->next_bridge) {
1342 		ret = drm_bridge_attach(bridge->encoder, dp->next_bridge,
1343 					bridge, flags);
1344 		if (ret < 0)
1345 			goto error;
1346 	}
1347 
1348 	/* Now that initialisation is complete, enable interrupts. */
1349 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_ALL);
1350 
1351 	return 0;
1352 
1353 error:
1354 	zynqmp_dp_aux_cleanup(dp);
1355 	return ret;
1356 }
1357 
1358 static void zynqmp_dp_bridge_detach(struct drm_bridge *bridge)
1359 {
1360 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1361 
1362 	zynqmp_dp_aux_cleanup(dp);
1363 }
1364 
1365 static enum drm_mode_status
1366 zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge,
1367 			    const struct drm_display_info *info,
1368 			    const struct drm_display_mode *mode)
1369 {
1370 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1371 	int rate;
1372 
1373 	if (mode->clock > ZYNQMP_MAX_FREQ) {
1374 		dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n",
1375 			mode->name);
1376 		drm_mode_debug_printmodeline(mode);
1377 		return MODE_CLOCK_HIGH;
1378 	}
1379 
1380 	/* Check with link rate and lane count */
1381 	rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
1382 				  dp->link_config.max_lanes, dp->config.bpp);
1383 	if (mode->clock > rate) {
1384 		dev_dbg(dp->dev, "filtered mode %s for high pixel rate\n",
1385 			mode->name);
1386 		drm_mode_debug_printmodeline(mode);
1387 		return MODE_CLOCK_HIGH;
1388 	}
1389 
1390 	return MODE_OK;
1391 }
1392 
1393 static void zynqmp_dp_bridge_atomic_enable(struct drm_bridge *bridge,
1394 					   struct drm_bridge_state *old_bridge_state)
1395 {
1396 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1397 	struct drm_atomic_state *state = old_bridge_state->base.state;
1398 	const struct drm_crtc_state *crtc_state;
1399 	const struct drm_display_mode *adjusted_mode;
1400 	const struct drm_display_mode *mode;
1401 	struct drm_connector *connector;
1402 	struct drm_crtc *crtc;
1403 	unsigned int i;
1404 	int rate;
1405 	int ret;
1406 
1407 	pm_runtime_get_sync(dp->dev);
1408 
1409 	zynqmp_dp_disp_enable(dp, old_bridge_state);
1410 
1411 	/*
1412 	 * Retrieve the CRTC mode and adjusted mode. This requires a little
1413 	 * dance to go from the bridge to the encoder, to the connector and to
1414 	 * the CRTC.
1415 	 */
1416 	connector = drm_atomic_get_new_connector_for_encoder(state,
1417 							     bridge->encoder);
1418 	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
1419 	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
1420 	adjusted_mode = &crtc_state->adjusted_mode;
1421 	mode = &crtc_state->mode;
1422 
1423 	zynqmp_dp_set_format(dp, &connector->display_info,
1424 			     ZYNQMP_DPSUB_FORMAT_RGB, 8);
1425 
1426 	/* Check again as bpp or format might have been changed */
1427 	rate = zynqmp_dp_max_rate(dp->link_config.max_rate,
1428 				  dp->link_config.max_lanes, dp->config.bpp);
1429 	if (mode->clock > rate) {
1430 		dev_err(dp->dev, "mode %s has too high pixel rate\n",
1431 			mode->name);
1432 		drm_mode_debug_printmodeline(mode);
1433 	}
1434 
1435 	/* Configure the mode */
1436 	ret = zynqmp_dp_mode_configure(dp, adjusted_mode->clock, 0);
1437 	if (ret < 0) {
1438 		pm_runtime_put_sync(dp->dev);
1439 		return;
1440 	}
1441 
1442 	zynqmp_dp_encoder_mode_set_transfer_unit(dp, adjusted_mode);
1443 	zynqmp_dp_encoder_mode_set_stream(dp, adjusted_mode);
1444 
1445 	/* Enable the encoder */
1446 	dp->enabled = true;
1447 	zynqmp_dp_update_misc(dp);
1448 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1449 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 1);
1450 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, 0);
1451 	if (dp->status == connector_status_connected) {
1452 		for (i = 0; i < 3; i++) {
1453 			ret = drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER,
1454 						 DP_SET_POWER_D0);
1455 			if (ret == 1)
1456 				break;
1457 			usleep_range(300, 500);
1458 		}
1459 		/* Some monitors take time to wake up properly */
1460 		msleep(zynqmp_dp_power_on_delay_ms);
1461 	}
1462 	if (ret != 1)
1463 		dev_dbg(dp->dev, "DP aux failed\n");
1464 	else
1465 		zynqmp_dp_train_loop(dp);
1466 	zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET,
1467 			ZYNQMP_DP_SOFTWARE_RESET_ALL);
1468 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1);
1469 }
1470 
1471 static void zynqmp_dp_bridge_atomic_disable(struct drm_bridge *bridge,
1472 					    struct drm_bridge_state *old_bridge_state)
1473 {
1474 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1475 
1476 	dp->enabled = false;
1477 	cancel_delayed_work(&dp->hpd_work);
1478 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 0);
1479 	drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
1480 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1481 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1482 	if (zynqmp_dpsub_audio_enabled(dp->dpsub))
1483 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 0);
1484 
1485 	zynqmp_dp_disp_disable(dp, old_bridge_state);
1486 
1487 	pm_runtime_put_sync(dp->dev);
1488 }
1489 
1490 #define ZYNQMP_DP_MIN_H_BACKPORCH	20
1491 
1492 static int zynqmp_dp_bridge_atomic_check(struct drm_bridge *bridge,
1493 					 struct drm_bridge_state *bridge_state,
1494 					 struct drm_crtc_state *crtc_state,
1495 					 struct drm_connector_state *conn_state)
1496 {
1497 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1498 	struct drm_display_mode *mode = &crtc_state->mode;
1499 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1500 	int diff = mode->htotal - mode->hsync_end;
1501 
1502 	/*
1503 	 * ZynqMP DP requires horizontal backporch to be greater than 12.
1504 	 * This limitation may not be compatible with the sink device.
1505 	 */
1506 	if (diff < ZYNQMP_DP_MIN_H_BACKPORCH) {
1507 		int vrefresh = (adjusted_mode->clock * 1000) /
1508 			       (adjusted_mode->vtotal * adjusted_mode->htotal);
1509 
1510 		dev_dbg(dp->dev, "hbackporch adjusted: %d to %d",
1511 			diff, ZYNQMP_DP_MIN_H_BACKPORCH - diff);
1512 		diff = ZYNQMP_DP_MIN_H_BACKPORCH - diff;
1513 		adjusted_mode->htotal += diff;
1514 		adjusted_mode->clock = adjusted_mode->vtotal *
1515 				       adjusted_mode->htotal * vrefresh / 1000;
1516 	}
1517 
1518 	return 0;
1519 }
1520 
1521 static enum drm_connector_status zynqmp_dp_bridge_detect(struct drm_bridge *bridge)
1522 {
1523 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1524 	struct zynqmp_dp_link_config *link_config = &dp->link_config;
1525 	u32 state, i;
1526 	int ret;
1527 
1528 	/*
1529 	 * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to
1530 	 * get the HPD signal with some monitors.
1531 	 */
1532 	for (i = 0; i < 10; i++) {
1533 		state = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
1534 		if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD)
1535 			break;
1536 		msleep(100);
1537 	}
1538 
1539 	if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD) {
1540 		ret = drm_dp_dpcd_read(&dp->aux, 0x0, dp->dpcd,
1541 				       sizeof(dp->dpcd));
1542 		if (ret < 0) {
1543 			dev_dbg(dp->dev, "DPCD read failed");
1544 			goto disconnected;
1545 		}
1546 
1547 		link_config->max_rate = min_t(int,
1548 					      drm_dp_max_link_rate(dp->dpcd),
1549 					      DP_HIGH_BIT_RATE2);
1550 		link_config->max_lanes = min_t(u8,
1551 					       drm_dp_max_lane_count(dp->dpcd),
1552 					       dp->num_lanes);
1553 
1554 		dp->status = connector_status_connected;
1555 		return connector_status_connected;
1556 	}
1557 
1558 disconnected:
1559 	dp->status = connector_status_disconnected;
1560 	return connector_status_disconnected;
1561 }
1562 
1563 static struct edid *zynqmp_dp_bridge_get_edid(struct drm_bridge *bridge,
1564 					      struct drm_connector *connector)
1565 {
1566 	struct zynqmp_dp *dp = bridge_to_dp(bridge);
1567 
1568 	return drm_get_edid(connector, &dp->aux.ddc);
1569 }
1570 
1571 static const struct drm_bridge_funcs zynqmp_dp_bridge_funcs = {
1572 	.attach = zynqmp_dp_bridge_attach,
1573 	.detach = zynqmp_dp_bridge_detach,
1574 	.mode_valid = zynqmp_dp_bridge_mode_valid,
1575 	.atomic_enable = zynqmp_dp_bridge_atomic_enable,
1576 	.atomic_disable = zynqmp_dp_bridge_atomic_disable,
1577 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1578 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1579 	.atomic_reset = drm_atomic_helper_bridge_reset,
1580 	.atomic_check = zynqmp_dp_bridge_atomic_check,
1581 	.detect = zynqmp_dp_bridge_detect,
1582 	.get_edid = zynqmp_dp_bridge_get_edid,
1583 };
1584 
1585 /* -----------------------------------------------------------------------------
1586  * Interrupt Handling
1587  */
1588 
1589 /**
1590  * zynqmp_dp_enable_vblank - Enable vblank
1591  * @dp: DisplayPort IP core structure
1592  *
1593  * Enable vblank interrupt
1594  */
1595 void zynqmp_dp_enable_vblank(struct zynqmp_dp *dp)
1596 {
1597 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_VBLANK_START);
1598 }
1599 
1600 /**
1601  * zynqmp_dp_disable_vblank - Disable vblank
1602  * @dp: DisplayPort IP core structure
1603  *
1604  * Disable vblank interrupt
1605  */
1606 void zynqmp_dp_disable_vblank(struct zynqmp_dp *dp)
1607 {
1608 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_VBLANK_START);
1609 }
1610 
1611 static void zynqmp_dp_hpd_work_func(struct work_struct *work)
1612 {
1613 	struct zynqmp_dp *dp = container_of(work, struct zynqmp_dp,
1614 					    hpd_work.work);
1615 	enum drm_connector_status status;
1616 
1617 	status = zynqmp_dp_bridge_detect(&dp->bridge);
1618 	drm_bridge_hpd_notify(&dp->bridge, status);
1619 }
1620 
1621 static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
1622 {
1623 	struct zynqmp_dp *dp = (struct zynqmp_dp *)data;
1624 	u32 status, mask;
1625 
1626 	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
1627 	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
1628 	if (!(status & ~mask))
1629 		return IRQ_NONE;
1630 
1631 	/* dbg for diagnostic, but not much that the driver can do */
1632 	if (status & ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK)
1633 		dev_dbg_ratelimited(dp->dev, "underflow interrupt\n");
1634 	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
1635 		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
1636 
1637 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
1638 
1639 	if (status & ZYNQMP_DP_INT_VBLANK_START)
1640 		zynqmp_dpsub_drm_handle_vblank(dp->dpsub);
1641 
1642 	if (status & ZYNQMP_DP_INT_HPD_EVENT)
1643 		schedule_delayed_work(&dp->hpd_work, 0);
1644 
1645 	if (status & ZYNQMP_DP_INT_HPD_IRQ) {
1646 		int ret;
1647 		u8 status[DP_LINK_STATUS_SIZE + 2];
1648 
1649 		ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
1650 				       DP_LINK_STATUS_SIZE + 2);
1651 		if (ret < 0)
1652 			goto handled;
1653 
1654 		if (status[4] & DP_LINK_STATUS_UPDATED ||
1655 		    !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) ||
1656 		    !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) {
1657 			zynqmp_dp_train_loop(dp);
1658 		}
1659 	}
1660 
1661 handled:
1662 	return IRQ_HANDLED;
1663 }
1664 
1665 /* -----------------------------------------------------------------------------
1666  * Initialization & Cleanup
1667  */
1668 
1669 int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub)
1670 {
1671 	struct platform_device *pdev = to_platform_device(dpsub->dev);
1672 	struct drm_bridge *bridge;
1673 	struct zynqmp_dp *dp;
1674 	struct resource *res;
1675 	int ret;
1676 
1677 	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
1678 	if (!dp)
1679 		return -ENOMEM;
1680 
1681 	dp->dev = &pdev->dev;
1682 	dp->dpsub = dpsub;
1683 	dp->status = connector_status_disconnected;
1684 
1685 	INIT_DELAYED_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func);
1686 
1687 	/* Acquire all resources (IOMEM, IRQ and PHYs). */
1688 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp");
1689 	dp->iomem = devm_ioremap_resource(dp->dev, res);
1690 	if (IS_ERR(dp->iomem)) {
1691 		ret = PTR_ERR(dp->iomem);
1692 		goto err_free;
1693 	}
1694 
1695 	dp->irq = platform_get_irq(pdev, 0);
1696 	if (dp->irq < 0) {
1697 		ret = dp->irq;
1698 		goto err_free;
1699 	}
1700 
1701 	dp->reset = devm_reset_control_get(dp->dev, NULL);
1702 	if (IS_ERR(dp->reset)) {
1703 		if (PTR_ERR(dp->reset) != -EPROBE_DEFER)
1704 			dev_err(dp->dev, "failed to get reset: %ld\n",
1705 				PTR_ERR(dp->reset));
1706 		ret = PTR_ERR(dp->reset);
1707 		goto err_free;
1708 	}
1709 
1710 	ret = zynqmp_dp_reset(dp, false);
1711 	if (ret < 0)
1712 		goto err_free;
1713 
1714 	ret = zynqmp_dp_phy_probe(dp);
1715 	if (ret)
1716 		goto err_reset;
1717 
1718 	/* Initialize the bridge. */
1719 	bridge = &dp->bridge;
1720 	bridge->funcs = &zynqmp_dp_bridge_funcs;
1721 	bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID
1722 		    | DRM_BRIDGE_OP_HPD;
1723 	bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
1724 	dpsub->bridge = bridge;
1725 
1726 	/*
1727 	 * Acquire the next bridge in the chain. Ignore errors caused by port@5
1728 	 * not being connected for backward-compatibility with older DTs.
1729 	 */
1730 	ret = drm_of_find_panel_or_bridge(dp->dev->of_node, 5, 0, NULL,
1731 					  &dp->next_bridge);
1732 	if (ret < 0 && ret != -ENODEV)
1733 		goto err_reset;
1734 
1735 	/* Initialize the hardware. */
1736 	dp->config.misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK;
1737 	zynqmp_dp_set_format(dp, NULL, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1738 
1739 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1740 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1741 	zynqmp_dp_set(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
1742 	zynqmp_dp_write(dp, ZYNQMP_DP_FORCE_SCRAMBLER_RESET, 1);
1743 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1744 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1745 
1746 	ret = zynqmp_dp_phy_init(dp);
1747 	if (ret)
1748 		goto err_reset;
1749 
1750 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1);
1751 
1752 	/*
1753 	 * Now that the hardware is initialized and won't generate spurious
1754 	 * interrupts, request the IRQ.
1755 	 */
1756 	ret = devm_request_threaded_irq(dp->dev, dp->irq, NULL,
1757 					zynqmp_dp_irq_handler, IRQF_ONESHOT,
1758 					dev_name(dp->dev), dp);
1759 	if (ret < 0)
1760 		goto err_phy_exit;
1761 
1762 	dpsub->dp = dp;
1763 
1764 	dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n",
1765 		dp->num_lanes);
1766 
1767 	return 0;
1768 
1769 err_phy_exit:
1770 	zynqmp_dp_phy_exit(dp);
1771 err_reset:
1772 	zynqmp_dp_reset(dp, true);
1773 err_free:
1774 	kfree(dp);
1775 	return ret;
1776 }
1777 
1778 void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub)
1779 {
1780 	struct zynqmp_dp *dp = dpsub->dp;
1781 
1782 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL);
1783 	disable_irq(dp->irq);
1784 
1785 	cancel_delayed_work_sync(&dp->hpd_work);
1786 
1787 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1788 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1789 
1790 	zynqmp_dp_phy_exit(dp);
1791 	zynqmp_dp_reset(dp, true);
1792 }
1793