xref: /openbmc/linux/drivers/gpu/drm/xlnx/zynqmp_dp.c (revision 8dda2eac)
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/drm_atomic_helper.h>
13 #include <drm/drm_connector.h>
14 #include <drm/drm_crtc.h>
15 #include <drm/drm_device.h>
16 #include <drm/drm_dp_helper.h>
17 #include <drm/drm_edid.h>
18 #include <drm/drm_encoder.h>
19 #include <drm/drm_managed.h>
20 #include <drm/drm_modes.h>
21 #include <drm/drm_of.h>
22 #include <drm/drm_probe_helper.h>
23 #include <drm/drm_simple_kms_helper.h>
24 
25 #include <linux/clk.h>
26 #include <linux/delay.h>
27 #include <linux/device.h>
28 #include <linux/module.h>
29 #include <linux/platform_device.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/phy/phy.h>
32 #include <linux/reset.h>
33 
34 #include "zynqmp_disp.h"
35 #include "zynqmp_dp.h"
36 #include "zynqmp_dpsub.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  * @encoder: the drm encoder structure
280  * @connector: the drm connector structure
281  * @dev: device structure
282  * @dpsub: Display subsystem
283  * @drm: DRM core
284  * @iomem: device I/O memory for register access
285  * @reset: reset controller
286  * @irq: irq
287  * @config: IP core configuration from DTS
288  * @aux: aux channel
289  * @phy: PHY handles for DP lanes
290  * @num_lanes: number of enabled phy lanes
291  * @hpd_work: hot plug detection worker
292  * @status: connection status
293  * @enabled: flag to indicate if the device is enabled
294  * @dpcd: DP configuration data from currently connected sink device
295  * @link_config: common link configuration between IP core and sink device
296  * @mode: current mode between IP core and sink device
297  * @train_set: set of training data
298  */
299 struct zynqmp_dp {
300 	struct drm_encoder encoder;
301 	struct drm_connector connector;
302 	struct device *dev;
303 	struct zynqmp_dpsub *dpsub;
304 	struct drm_device *drm;
305 	void __iomem *iomem;
306 	struct reset_control *reset;
307 	int irq;
308 
309 	struct zynqmp_dp_config config;
310 	struct drm_dp_aux aux;
311 	struct phy *phy[ZYNQMP_DP_MAX_LANES];
312 	u8 num_lanes;
313 	struct delayed_work hpd_work;
314 	enum drm_connector_status status;
315 	bool enabled;
316 
317 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
318 	struct zynqmp_dp_link_config link_config;
319 	struct zynqmp_dp_mode mode;
320 	u8 train_set[ZYNQMP_DP_MAX_LANES];
321 };
322 
323 static inline struct zynqmp_dp *encoder_to_dp(struct drm_encoder *encoder)
324 {
325 	return container_of(encoder, struct zynqmp_dp, encoder);
326 }
327 
328 static inline struct zynqmp_dp *connector_to_dp(struct drm_connector *connector)
329 {
330 	return container_of(connector, struct zynqmp_dp, connector);
331 }
332 
333 static void zynqmp_dp_write(struct zynqmp_dp *dp, int offset, u32 val)
334 {
335 	writel(val, dp->iomem + offset);
336 }
337 
338 static u32 zynqmp_dp_read(struct zynqmp_dp *dp, int offset)
339 {
340 	return readl(dp->iomem + offset);
341 }
342 
343 static void zynqmp_dp_clr(struct zynqmp_dp *dp, int offset, u32 clr)
344 {
345 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) & ~clr);
346 }
347 
348 static void zynqmp_dp_set(struct zynqmp_dp *dp, int offset, u32 set)
349 {
350 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) | set);
351 }
352 
353 /* -----------------------------------------------------------------------------
354  * PHY Handling
355  */
356 
357 #define RST_TIMEOUT_MS			1000
358 
359 static int zynqmp_dp_reset(struct zynqmp_dp *dp, bool assert)
360 {
361 	unsigned long timeout;
362 
363 	if (assert)
364 		reset_control_assert(dp->reset);
365 	else
366 		reset_control_deassert(dp->reset);
367 
368 	/* Wait for the (de)assert to complete. */
369 	timeout = jiffies + msecs_to_jiffies(RST_TIMEOUT_MS);
370 	while (!time_after_eq(jiffies, timeout)) {
371 		bool status = !!reset_control_status(dp->reset);
372 
373 		if (assert == status)
374 			return 0;
375 
376 		cpu_relax();
377 	}
378 
379 	dev_err(dp->dev, "reset %s timeout\n", assert ? "assert" : "deassert");
380 	return -ETIMEDOUT;
381 }
382 
383 /**
384  * zynqmp_dp_phy_init - Initialize the phy
385  * @dp: DisplayPort IP core structure
386  *
387  * Initialize the phy.
388  *
389  * Return: 0 if the phy instances are initialized correctly, or the error code
390  * returned from the callee functions.
391  */
392 static int zynqmp_dp_phy_init(struct zynqmp_dp *dp)
393 {
394 	int ret;
395 	int i;
396 
397 	for (i = 0; i < dp->num_lanes; i++) {
398 		ret = phy_init(dp->phy[i]);
399 		if (ret) {
400 			dev_err(dp->dev, "failed to init phy lane %d\n", i);
401 			return ret;
402 		}
403 	}
404 
405 	ret = zynqmp_dp_reset(dp, false);
406 	if (ret < 0)
407 		return ret;
408 
409 	zynqmp_dp_clr(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
410 
411 	/*
412 	 * Power on lanes in reverse order as only lane 0 waits for the PLL to
413 	 * lock.
414 	 */
415 	for (i = dp->num_lanes - 1; i >= 0; i--) {
416 		ret = phy_power_on(dp->phy[i]);
417 		if (ret) {
418 			dev_err(dp->dev, "failed to power on phy lane %d\n", i);
419 			return ret;
420 		}
421 	}
422 
423 	return 0;
424 }
425 
426 /**
427  * zynqmp_dp_phy_exit - Exit the phy
428  * @dp: DisplayPort IP core structure
429  *
430  * Exit the phy.
431  */
432 static void zynqmp_dp_phy_exit(struct zynqmp_dp *dp)
433 {
434 	unsigned int i;
435 	int ret;
436 
437 	for (i = 0; i < dp->num_lanes; i++) {
438 		ret = phy_power_off(dp->phy[i]);
439 		if (ret)
440 			dev_err(dp->dev, "failed to power off phy(%d) %d\n", i,
441 				ret);
442 	}
443 
444 	zynqmp_dp_reset(dp, true);
445 
446 	for (i = 0; i < dp->num_lanes; i++) {
447 		ret = phy_exit(dp->phy[i]);
448 		if (ret)
449 			dev_err(dp->dev, "failed to exit phy(%d) %d\n", i, ret);
450 	}
451 }
452 
453 /**
454  * zynqmp_dp_phy_probe - Probe the PHYs
455  * @dp: DisplayPort IP core structure
456  *
457  * Probe PHYs for all lanes. Less PHYs may be available than the number of
458  * lanes, which is not considered an error as long as at least one PHY is
459  * found. The caller can check dp->num_lanes to check how many PHYs were found.
460  *
461  * Return:
462  * * 0				- Success
463  * * -ENXIO			- No PHY found
464  * * -EPROBE_DEFER		- Probe deferral requested
465  * * Other negative value	- PHY retrieval failure
466  */
467 static int zynqmp_dp_phy_probe(struct zynqmp_dp *dp)
468 {
469 	unsigned int i;
470 
471 	for (i = 0; i < ZYNQMP_DP_MAX_LANES; i++) {
472 		char phy_name[16];
473 		struct phy *phy;
474 
475 		snprintf(phy_name, sizeof(phy_name), "dp-phy%d", i);
476 		phy = devm_phy_get(dp->dev, phy_name);
477 
478 		if (IS_ERR(phy)) {
479 			switch (PTR_ERR(phy)) {
480 			case -ENODEV:
481 				if (dp->num_lanes)
482 					return 0;
483 
484 				dev_err(dp->dev, "no PHY found\n");
485 				return -ENXIO;
486 
487 			case -EPROBE_DEFER:
488 				return -EPROBE_DEFER;
489 
490 			default:
491 				dev_err(dp->dev, "failed to get PHY lane %u\n",
492 					i);
493 				return PTR_ERR(phy);
494 			}
495 		}
496 
497 		dp->phy[i] = phy;
498 		dp->num_lanes++;
499 	}
500 
501 	return 0;
502 }
503 
504 /**
505  * zynqmp_dp_phy_ready - Check if PHY is ready
506  * @dp: DisplayPort IP core structure
507  *
508  * Check if PHY is ready. If PHY is not ready, wait 1ms to check for 100 times.
509  * This amount of delay was suggested by IP designer.
510  *
511  * Return: 0 if PHY is ready, or -ENODEV if PHY is not ready.
512  */
513 static int zynqmp_dp_phy_ready(struct zynqmp_dp *dp)
514 {
515 	u32 i, reg, ready;
516 
517 	ready = (1 << dp->num_lanes) - 1;
518 
519 	/* Wait for 100 * 1ms. This should be enough time for PHY to be ready */
520 	for (i = 0; ; i++) {
521 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_PHY_STATUS);
522 		if ((reg & ready) == ready)
523 			return 0;
524 
525 		if (i == 100) {
526 			dev_err(dp->dev, "PHY isn't ready\n");
527 			return -ENODEV;
528 		}
529 
530 		usleep_range(1000, 1100);
531 	}
532 
533 	return 0;
534 }
535 
536 /* -----------------------------------------------------------------------------
537  * DisplayPort Link Training
538  */
539 
540 /**
541  * zynqmp_dp_max_rate - Calculate and return available max pixel clock
542  * @link_rate: link rate (Kilo-bytes / sec)
543  * @lane_num: number of lanes
544  * @bpp: bits per pixel
545  *
546  * Return: max pixel clock (KHz) supported by current link config.
547  */
548 static inline int zynqmp_dp_max_rate(int link_rate, u8 lane_num, u8 bpp)
549 {
550 	return link_rate * lane_num * 8 / bpp;
551 }
552 
553 /**
554  * zynqmp_dp_mode_configure - Configure the link values
555  * @dp: DisplayPort IP core structure
556  * @pclock: pixel clock for requested display mode
557  * @current_bw: current link rate
558  *
559  * Find the link configuration values, rate and lane count for requested pixel
560  * clock @pclock. The @pclock is stored in the mode to be used in other
561  * functions later. The returned rate is downshifted from the current rate
562  * @current_bw.
563  *
564  * Return: Current link rate code, or -EINVAL.
565  */
566 static int zynqmp_dp_mode_configure(struct zynqmp_dp *dp, int pclock,
567 				    u8 current_bw)
568 {
569 	int max_rate = dp->link_config.max_rate;
570 	u8 bw_code;
571 	u8 max_lanes = dp->link_config.max_lanes;
572 	u8 max_link_rate_code = drm_dp_link_rate_to_bw_code(max_rate);
573 	u8 bpp = dp->config.bpp;
574 	u8 lane_cnt;
575 
576 	/* Downshift from current bandwidth */
577 	switch (current_bw) {
578 	case DP_LINK_BW_5_4:
579 		bw_code = DP_LINK_BW_2_7;
580 		break;
581 	case DP_LINK_BW_2_7:
582 		bw_code = DP_LINK_BW_1_62;
583 		break;
584 	case DP_LINK_BW_1_62:
585 		dev_err(dp->dev, "can't downshift. already lowest link rate\n");
586 		return -EINVAL;
587 	default:
588 		/* If not given, start with max supported */
589 		bw_code = max_link_rate_code;
590 		break;
591 	}
592 
593 	for (lane_cnt = 1; lane_cnt <= max_lanes; lane_cnt <<= 1) {
594 		int bw;
595 		u32 rate;
596 
597 		bw = drm_dp_bw_code_to_link_rate(bw_code);
598 		rate = zynqmp_dp_max_rate(bw, lane_cnt, bpp);
599 		if (pclock <= rate) {
600 			dp->mode.bw_code = bw_code;
601 			dp->mode.lane_cnt = lane_cnt;
602 			dp->mode.pclock = pclock;
603 			return dp->mode.bw_code;
604 		}
605 	}
606 
607 	dev_err(dp->dev, "failed to configure link values\n");
608 
609 	return -EINVAL;
610 }
611 
612 /**
613  * zynqmp_dp_adjust_train - Adjust train values
614  * @dp: DisplayPort IP core structure
615  * @link_status: link status from sink which contains requested training values
616  */
617 static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp,
618 				   u8 link_status[DP_LINK_STATUS_SIZE])
619 {
620 	u8 *train_set = dp->train_set;
621 	u8 voltage = 0, preemphasis = 0;
622 	u8 i;
623 
624 	for (i = 0; i < dp->mode.lane_cnt; i++) {
625 		u8 v = drm_dp_get_adjust_request_voltage(link_status, i);
626 		u8 p = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
627 
628 		if (v > voltage)
629 			voltage = v;
630 
631 		if (p > preemphasis)
632 			preemphasis = p;
633 	}
634 
635 	if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3)
636 		voltage |= DP_TRAIN_MAX_SWING_REACHED;
637 
638 	if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2)
639 		preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
640 
641 	for (i = 0; i < dp->mode.lane_cnt; i++)
642 		train_set[i] = voltage | preemphasis;
643 }
644 
645 /**
646  * zynqmp_dp_update_vs_emph - Update the training values
647  * @dp: DisplayPort IP core structure
648  *
649  * Update the training values based on the request from sink. The mapped values
650  * are predefined, and values(vs, pe, pc) are from the device manual.
651  *
652  * Return: 0 if vs and emph are updated successfully, or the error code returned
653  * by drm_dp_dpcd_write().
654  */
655 static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
656 {
657 	unsigned int i;
658 	int ret;
659 
660 	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->train_set,
661 				dp->mode.lane_cnt);
662 	if (ret < 0)
663 		return ret;
664 
665 	for (i = 0; i < dp->mode.lane_cnt; i++) {
666 		u32 reg = ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0 + i * 4;
667 		union phy_configure_opts opts = { 0 };
668 		u8 train = dp->train_set[i];
669 
670 		opts.dp.voltage[0] = (train & DP_TRAIN_VOLTAGE_SWING_MASK)
671 				   >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
672 		opts.dp.pre[0] = (train & DP_TRAIN_PRE_EMPHASIS_MASK)
673 			       >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
674 
675 		phy_configure(dp->phy[i], &opts);
676 
677 		zynqmp_dp_write(dp, reg, 0x2);
678 	}
679 
680 	return 0;
681 }
682 
683 /**
684  * zynqmp_dp_link_train_cr - Train clock recovery
685  * @dp: DisplayPort IP core structure
686  *
687  * Return: 0 if clock recovery train is done successfully, or corresponding
688  * error code.
689  */
690 static int zynqmp_dp_link_train_cr(struct zynqmp_dp *dp)
691 {
692 	u8 link_status[DP_LINK_STATUS_SIZE];
693 	u8 lane_cnt = dp->mode.lane_cnt;
694 	u8 vs = 0, tries = 0;
695 	u16 max_tries, i;
696 	bool cr_done;
697 	int ret;
698 
699 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
700 			DP_TRAINING_PATTERN_1);
701 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
702 				 DP_TRAINING_PATTERN_1 |
703 				 DP_LINK_SCRAMBLING_DISABLE);
704 	if (ret < 0)
705 		return ret;
706 
707 	/*
708 	 * 256 loops should be maximum iterations for 4 lanes and 4 values.
709 	 * So, This loop should exit before 512 iterations
710 	 */
711 	for (max_tries = 0; max_tries < 512; max_tries++) {
712 		ret = zynqmp_dp_update_vs_emph(dp);
713 		if (ret)
714 			return ret;
715 
716 		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
717 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
718 		if (ret < 0)
719 			return ret;
720 
721 		cr_done = drm_dp_clock_recovery_ok(link_status, lane_cnt);
722 		if (cr_done)
723 			break;
724 
725 		for (i = 0; i < lane_cnt; i++)
726 			if (!(dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED))
727 				break;
728 		if (i == lane_cnt)
729 			break;
730 
731 		if ((dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == vs)
732 			tries++;
733 		else
734 			tries = 0;
735 
736 		if (tries == DP_MAX_TRAINING_TRIES)
737 			break;
738 
739 		vs = dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
740 		zynqmp_dp_adjust_train(dp, link_status);
741 	}
742 
743 	if (!cr_done)
744 		return -EIO;
745 
746 	return 0;
747 }
748 
749 /**
750  * zynqmp_dp_link_train_ce - Train channel equalization
751  * @dp: DisplayPort IP core structure
752  *
753  * Return: 0 if channel equalization train is done successfully, or
754  * corresponding error code.
755  */
756 static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
757 {
758 	u8 link_status[DP_LINK_STATUS_SIZE];
759 	u8 lane_cnt = dp->mode.lane_cnt;
760 	u32 pat, tries;
761 	int ret;
762 	bool ce_done;
763 
764 	if (dp->dpcd[DP_DPCD_REV] >= DP_V1_2 &&
765 	    dp->dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED)
766 		pat = DP_TRAINING_PATTERN_3;
767 	else
768 		pat = DP_TRAINING_PATTERN_2;
769 
770 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET, pat);
771 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
772 				 pat | DP_LINK_SCRAMBLING_DISABLE);
773 	if (ret < 0)
774 		return ret;
775 
776 	for (tries = 0; tries < DP_MAX_TRAINING_TRIES; tries++) {
777 		ret = zynqmp_dp_update_vs_emph(dp);
778 		if (ret)
779 			return ret;
780 
781 		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
782 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
783 		if (ret < 0)
784 			return ret;
785 
786 		ce_done = drm_dp_channel_eq_ok(link_status, lane_cnt);
787 		if (ce_done)
788 			break;
789 
790 		zynqmp_dp_adjust_train(dp, link_status);
791 	}
792 
793 	if (!ce_done)
794 		return -EIO;
795 
796 	return 0;
797 }
798 
799 /**
800  * zynqmp_dp_link_train - Train the link
801  * @dp: DisplayPort IP core structure
802  *
803  * Return: 0 if all trains are done successfully, or corresponding error code.
804  */
805 static int zynqmp_dp_train(struct zynqmp_dp *dp)
806 {
807 	u32 reg;
808 	u8 bw_code = dp->mode.bw_code;
809 	u8 lane_cnt = dp->mode.lane_cnt;
810 	u8 aux_lane_cnt = lane_cnt;
811 	bool enhanced;
812 	int ret;
813 
814 	zynqmp_dp_write(dp, ZYNQMP_DP_LANE_COUNT_SET, lane_cnt);
815 	enhanced = drm_dp_enhanced_frame_cap(dp->dpcd);
816 	if (enhanced) {
817 		zynqmp_dp_write(dp, ZYNQMP_DP_ENHANCED_FRAME_EN, 1);
818 		aux_lane_cnt |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
819 	}
820 
821 	if (dp->dpcd[3] & 0x1) {
822 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 1);
823 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL,
824 				   DP_SPREAD_AMP_0_5);
825 	} else {
826 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 0);
827 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL, 0);
828 	}
829 
830 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET, aux_lane_cnt);
831 	if (ret < 0) {
832 		dev_err(dp->dev, "failed to set lane count\n");
833 		return ret;
834 	}
835 
836 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
837 				 DP_SET_ANSI_8B10B);
838 	if (ret < 0) {
839 		dev_err(dp->dev, "failed to set ANSI 8B/10B encoding\n");
840 		return ret;
841 	}
842 
843 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LINK_BW_SET, bw_code);
844 	if (ret < 0) {
845 		dev_err(dp->dev, "failed to set DP bandwidth\n");
846 		return ret;
847 	}
848 
849 	zynqmp_dp_write(dp, ZYNQMP_DP_LINK_BW_SET, bw_code);
850 	switch (bw_code) {
851 	case DP_LINK_BW_1_62:
852 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G;
853 		break;
854 	case DP_LINK_BW_2_7:
855 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G;
856 		break;
857 	case DP_LINK_BW_5_4:
858 	default:
859 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G;
860 		break;
861 	}
862 
863 	zynqmp_dp_write(dp, ZYNQMP_DP_PHY_CLOCK_SELECT, reg);
864 	ret = zynqmp_dp_phy_ready(dp);
865 	if (ret < 0)
866 		return ret;
867 
868 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 1);
869 	memset(dp->train_set, 0, sizeof(dp->train_set));
870 	ret = zynqmp_dp_link_train_cr(dp);
871 	if (ret)
872 		return ret;
873 
874 	ret = zynqmp_dp_link_train_ce(dp);
875 	if (ret)
876 		return ret;
877 
878 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
879 				 DP_TRAINING_PATTERN_DISABLE);
880 	if (ret < 0) {
881 		dev_err(dp->dev, "failed to disable training pattern\n");
882 		return ret;
883 	}
884 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
885 			DP_TRAINING_PATTERN_DISABLE);
886 
887 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 0);
888 
889 	return 0;
890 }
891 
892 /**
893  * zynqmp_dp_train_loop - Downshift the link rate during training
894  * @dp: DisplayPort IP core structure
895  *
896  * Train the link by downshifting the link rate if training is not successful.
897  */
898 static void zynqmp_dp_train_loop(struct zynqmp_dp *dp)
899 {
900 	struct zynqmp_dp_mode *mode = &dp->mode;
901 	u8 bw = mode->bw_code;
902 	int ret;
903 
904 	do {
905 		if (dp->status == connector_status_disconnected ||
906 		    !dp->enabled)
907 			return;
908 
909 		ret = zynqmp_dp_train(dp);
910 		if (!ret)
911 			return;
912 
913 		ret = zynqmp_dp_mode_configure(dp, mode->pclock, bw);
914 		if (ret < 0)
915 			goto err_out;
916 
917 		bw = ret;
918 	} while (bw >= DP_LINK_BW_1_62);
919 
920 err_out:
921 	dev_err(dp->dev, "failed to train the DP link\n");
922 }
923 
924 /* -----------------------------------------------------------------------------
925  * DisplayPort AUX
926  */
927 
928 #define AUX_READ_BIT	0x1
929 
930 /**
931  * zynqmp_dp_aux_cmd_submit - Submit aux command
932  * @dp: DisplayPort IP core structure
933  * @cmd: aux command
934  * @addr: aux address
935  * @buf: buffer for command data
936  * @bytes: number of bytes for @buf
937  * @reply: reply code to be returned
938  *
939  * Submit an aux command. All aux related commands, native or i2c aux
940  * read/write, are submitted through this function. The function is mapped to
941  * the transfer function of struct drm_dp_aux. This function involves in
942  * multiple register reads/writes, thus synchronization is needed, and it is
943  * done by drm_dp_helper using @hw_mutex. The calling thread goes into sleep
944  * if there's no immediate reply to the command submission. The reply code is
945  * returned at @reply if @reply != NULL.
946  *
947  * Return: 0 if the command is submitted properly, or corresponding error code:
948  * -EBUSY when there is any request already being processed
949  * -ETIMEDOUT when receiving reply is timed out
950  * -EIO when received bytes are less than requested
951  */
952 static int zynqmp_dp_aux_cmd_submit(struct zynqmp_dp *dp, u32 cmd, u16 addr,
953 				    u8 *buf, u8 bytes, u8 *reply)
954 {
955 	bool is_read = (cmd & AUX_READ_BIT) ? true : false;
956 	u32 reg, i;
957 
958 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
959 	if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST)
960 		return -EBUSY;
961 
962 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_ADDRESS, addr);
963 	if (!is_read)
964 		for (i = 0; i < bytes; i++)
965 			zynqmp_dp_write(dp, ZYNQMP_DP_AUX_WRITE_FIFO,
966 					buf[i]);
967 
968 	reg = cmd << ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT;
969 	if (!buf || !bytes)
970 		reg |= ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY;
971 	else
972 		reg |= (bytes - 1) << ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT;
973 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_COMMAND, reg);
974 
975 	/* Wait for reply to be delivered upto 2ms */
976 	for (i = 0; ; i++) {
977 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
978 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY)
979 			break;
980 
981 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT ||
982 		    i == 2)
983 			return -ETIMEDOUT;
984 
985 		usleep_range(1000, 1100);
986 	}
987 
988 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_CODE);
989 	if (reply)
990 		*reply = reg;
991 
992 	if (is_read &&
993 	    (reg == ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK ||
994 	     reg == ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK)) {
995 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_REPLY_DATA_COUNT);
996 		if ((reg & ZYNQMP_DP_REPLY_DATA_COUNT_MASK) != bytes)
997 			return -EIO;
998 
999 		for (i = 0; i < bytes; i++)
1000 			buf[i] = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_DATA);
1001 	}
1002 
1003 	return 0;
1004 }
1005 
1006 static ssize_t
1007 zynqmp_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
1008 {
1009 	struct zynqmp_dp *dp = container_of(aux, struct zynqmp_dp, aux);
1010 	int ret;
1011 	unsigned int i, iter;
1012 
1013 	/* Number of loops = timeout in msec / aux delay (400 usec) */
1014 	iter = zynqmp_dp_aux_timeout_ms * 1000 / 400;
1015 	iter = iter ? iter : 1;
1016 
1017 	for (i = 0; i < iter; i++) {
1018 		ret = zynqmp_dp_aux_cmd_submit(dp, msg->request, msg->address,
1019 					       msg->buffer, msg->size,
1020 					       &msg->reply);
1021 		if (!ret) {
1022 			dev_dbg(dp->dev, "aux %d retries\n", i);
1023 			return msg->size;
1024 		}
1025 
1026 		if (dp->status == connector_status_disconnected) {
1027 			dev_dbg(dp->dev, "no connected aux device\n");
1028 			return -ENODEV;
1029 		}
1030 
1031 		usleep_range(400, 500);
1032 	}
1033 
1034 	dev_dbg(dp->dev, "failed to do aux transfer (%d)\n", ret);
1035 
1036 	return ret;
1037 }
1038 
1039 /**
1040  * zynqmp_dp_aux_init - Initialize and register the DP AUX
1041  * @dp: DisplayPort IP core structure
1042  *
1043  * Program the AUX clock divider and filter and register the DP AUX adapter.
1044  *
1045  * Return: 0 on success, error value otherwise
1046  */
1047 static int zynqmp_dp_aux_init(struct zynqmp_dp *dp)
1048 {
1049 	unsigned long rate;
1050 	unsigned int w;
1051 
1052 	/*
1053 	 * The AUX_SIGNAL_WIDTH_FILTER is the number of APB clock cycles
1054 	 * corresponding to the AUX pulse. Allowable values are 8, 16, 24, 32,
1055 	 * 40 and 48. The AUX pulse width must be between 0.4µs and 0.6µs,
1056 	 * compute the w / 8 value corresponding to 0.4µs rounded up, and make
1057 	 * sure it stays below 0.6µs and within the allowable values.
1058 	 */
1059 	rate = clk_get_rate(dp->dpsub->apb_clk);
1060 	w = DIV_ROUND_UP(4 * rate, 1000 * 1000 * 10 * 8) * 8;
1061 	if (w > 6 * rate / (1000 * 1000 * 10) || w > 48) {
1062 		dev_err(dp->dev, "aclk frequency too high\n");
1063 		return -EINVAL;
1064 	}
1065 
1066 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_CLK_DIVIDER,
1067 			(w << ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT) |
1068 			(rate / (1000 * 1000)));
1069 
1070 	dp->aux.name = "ZynqMP DP AUX";
1071 	dp->aux.dev = dp->dev;
1072 	dp->aux.drm_dev = dp->drm;
1073 	dp->aux.transfer = zynqmp_dp_aux_transfer;
1074 
1075 	return drm_dp_aux_register(&dp->aux);
1076 }
1077 
1078 /**
1079  * zynqmp_dp_aux_cleanup - Cleanup the DP AUX
1080  * @dp: DisplayPort IP core structure
1081  *
1082  * Unregister the DP AUX adapter.
1083  */
1084 static void zynqmp_dp_aux_cleanup(struct zynqmp_dp *dp)
1085 {
1086 	drm_dp_aux_unregister(&dp->aux);
1087 }
1088 
1089 /* -----------------------------------------------------------------------------
1090  * DisplayPort Generic Support
1091  */
1092 
1093 /**
1094  * zynqmp_dp_update_misc - Write the misc registers
1095  * @dp: DisplayPort IP core structure
1096  *
1097  * The misc register values are stored in the structure, and this
1098  * function applies the values into the registers.
1099  */
1100 static void zynqmp_dp_update_misc(struct zynqmp_dp *dp)
1101 {
1102 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC0, dp->config.misc0);
1103 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC1, dp->config.misc1);
1104 }
1105 
1106 /**
1107  * zynqmp_dp_set_format - Set the input format
1108  * @dp: DisplayPort IP core structure
1109  * @format: input format
1110  * @bpc: bits per component
1111  *
1112  * Update misc register values based on input @format and @bpc.
1113  *
1114  * Return: 0 on success, or -EINVAL.
1115  */
1116 static int zynqmp_dp_set_format(struct zynqmp_dp *dp,
1117 				enum zynqmp_dpsub_format format,
1118 				unsigned int bpc)
1119 {
1120 	static const struct drm_display_info *display;
1121 	struct zynqmp_dp_config *config = &dp->config;
1122 	unsigned int num_colors;
1123 
1124 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK;
1125 	config->misc1 &= ~ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1126 
1127 	switch (format) {
1128 	case ZYNQMP_DPSUB_FORMAT_RGB:
1129 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB;
1130 		num_colors = 3;
1131 		break;
1132 
1133 	case ZYNQMP_DPSUB_FORMAT_YCRCB444:
1134 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444;
1135 		num_colors = 3;
1136 		break;
1137 
1138 	case ZYNQMP_DPSUB_FORMAT_YCRCB422:
1139 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422;
1140 		num_colors = 2;
1141 		break;
1142 
1143 	case ZYNQMP_DPSUB_FORMAT_YONLY:
1144 		config->misc1 |= ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1145 		num_colors = 1;
1146 		break;
1147 
1148 	default:
1149 		dev_err(dp->dev, "Invalid colormetry in DT\n");
1150 		return -EINVAL;
1151 	}
1152 
1153 	display = &dp->connector.display_info;
1154 	if (display->bpc && bpc > display->bpc) {
1155 		dev_warn(dp->dev,
1156 			 "downgrading requested %ubpc to display limit %ubpc\n",
1157 			 bpc, display->bpc);
1158 		bpc = display->bpc;
1159 	}
1160 
1161 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK;
1162 
1163 	switch (bpc) {
1164 	case 6:
1165 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6;
1166 		break;
1167 	case 8:
1168 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1169 		break;
1170 	case 10:
1171 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10;
1172 		break;
1173 	case 12:
1174 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12;
1175 		break;
1176 	case 16:
1177 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16;
1178 		break;
1179 	default:
1180 		dev_warn(dp->dev, "Not supported bpc (%u). fall back to 8bpc\n",
1181 			 bpc);
1182 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1183 		bpc = 8;
1184 		break;
1185 	}
1186 
1187 	/* Update the current bpp based on the format. */
1188 	config->bpp = bpc * num_colors;
1189 
1190 	return 0;
1191 }
1192 
1193 /**
1194  * zynqmp_dp_encoder_mode_set_transfer_unit - Set the transfer unit values
1195  * @dp: DisplayPort IP core structure
1196  * @mode: requested display mode
1197  *
1198  * Set the transfer unit, and calculate all transfer unit size related values.
1199  * Calculation is based on DP and IP core specification.
1200  */
1201 static void
1202 zynqmp_dp_encoder_mode_set_transfer_unit(struct zynqmp_dp *dp,
1203 					 struct drm_display_mode *mode)
1204 {
1205 	u32 tu = ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF;
1206 	u32 bw, vid_kbytes, avg_bytes_per_tu, init_wait;
1207 
1208 	/* Use the max transfer unit size (default) */
1209 	zynqmp_dp_write(dp, ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE, tu);
1210 
1211 	vid_kbytes = mode->clock * (dp->config.bpp / 8);
1212 	bw = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1213 	avg_bytes_per_tu = vid_kbytes * tu / (dp->mode.lane_cnt * bw / 1000);
1214 	zynqmp_dp_write(dp, ZYNQMP_DP_MIN_BYTES_PER_TU,
1215 			avg_bytes_per_tu / 1000);
1216 	zynqmp_dp_write(dp, ZYNQMP_DP_FRAC_BYTES_PER_TU,
1217 			avg_bytes_per_tu % 1000);
1218 
1219 	/* Configure the initial wait cycle based on transfer unit size */
1220 	if (tu < (avg_bytes_per_tu / 1000))
1221 		init_wait = 0;
1222 	else if ((avg_bytes_per_tu / 1000) <= 4)
1223 		init_wait = tu;
1224 	else
1225 		init_wait = tu - avg_bytes_per_tu / 1000;
1226 
1227 	zynqmp_dp_write(dp, ZYNQMP_DP_INIT_WAIT, init_wait);
1228 }
1229 
1230 /**
1231  * zynqmp_dp_encoder_mode_set_stream - Configure the main stream
1232  * @dp: DisplayPort IP core structure
1233  * @mode: requested display mode
1234  *
1235  * Configure the main stream based on the requested mode @mode. Calculation is
1236  * based on IP core specification.
1237  */
1238 static void zynqmp_dp_encoder_mode_set_stream(struct zynqmp_dp *dp,
1239 					      const struct drm_display_mode *mode)
1240 {
1241 	u8 lane_cnt = dp->mode.lane_cnt;
1242 	u32 reg, wpl;
1243 	unsigned int rate;
1244 
1245 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HTOTAL, mode->htotal);
1246 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VTOTAL, mode->vtotal);
1247 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_POLARITY,
1248 			(!!(mode->flags & DRM_MODE_FLAG_PVSYNC) <<
1249 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT) |
1250 			(!!(mode->flags & DRM_MODE_FLAG_PHSYNC) <<
1251 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT));
1252 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSWIDTH,
1253 			mode->hsync_end - mode->hsync_start);
1254 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSWIDTH,
1255 			mode->vsync_end - mode->vsync_start);
1256 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HRES, mode->hdisplay);
1257 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VRES, mode->vdisplay);
1258 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSTART,
1259 			mode->htotal - mode->hsync_start);
1260 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSTART,
1261 			mode->vtotal - mode->vsync_start);
1262 
1263 	/* In synchronous mode, set the diviers */
1264 	if (dp->config.misc0 & ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK) {
1265 		reg = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1266 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_N_VID, reg);
1267 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_M_VID, mode->clock);
1268 		rate = zynqmp_disp_get_audio_clk_rate(dp->dpsub->disp);
1269 		if (rate) {
1270 			dev_dbg(dp->dev, "Audio rate: %d\n", rate / 512);
1271 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_N_AUD, reg);
1272 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_M_AUD, rate / 1000);
1273 		}
1274 	}
1275 
1276 	/* Only 2 channel audio is supported now */
1277 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1278 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CHANNELS, 1);
1279 
1280 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_PIX_WIDTH, 1);
1281 
1282 	/* Translate to the native 16 bit datapath based on IP core spec */
1283 	wpl = (mode->hdisplay * dp->config.bpp + 15) / 16;
1284 	reg = wpl + wpl % lane_cnt - lane_cnt;
1285 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_DATA_COUNT_PER_LANE, reg);
1286 }
1287 
1288 /* -----------------------------------------------------------------------------
1289  * DRM Connector
1290  */
1291 
1292 static enum drm_connector_status
1293 zynqmp_dp_connector_detect(struct drm_connector *connector, bool force)
1294 {
1295 	struct zynqmp_dp *dp = connector_to_dp(connector);
1296 	struct zynqmp_dp_link_config *link_config = &dp->link_config;
1297 	u32 state, i;
1298 	int ret;
1299 
1300 	/*
1301 	 * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to
1302 	 * get the HPD signal with some monitors.
1303 	 */
1304 	for (i = 0; i < 10; i++) {
1305 		state = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
1306 		if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD)
1307 			break;
1308 		msleep(100);
1309 	}
1310 
1311 	if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD) {
1312 		ret = drm_dp_dpcd_read(&dp->aux, 0x0, dp->dpcd,
1313 				       sizeof(dp->dpcd));
1314 		if (ret < 0) {
1315 			dev_dbg(dp->dev, "DPCD read failed");
1316 			goto disconnected;
1317 		}
1318 
1319 		link_config->max_rate = min_t(int,
1320 					      drm_dp_max_link_rate(dp->dpcd),
1321 					      DP_HIGH_BIT_RATE2);
1322 		link_config->max_lanes = min_t(u8,
1323 					       drm_dp_max_lane_count(dp->dpcd),
1324 					       dp->num_lanes);
1325 
1326 		dp->status = connector_status_connected;
1327 		return connector_status_connected;
1328 	}
1329 
1330 disconnected:
1331 	dp->status = connector_status_disconnected;
1332 	return connector_status_disconnected;
1333 }
1334 
1335 static int zynqmp_dp_connector_get_modes(struct drm_connector *connector)
1336 {
1337 	struct zynqmp_dp *dp = connector_to_dp(connector);
1338 	struct edid *edid;
1339 	int ret;
1340 
1341 	edid = drm_get_edid(connector, &dp->aux.ddc);
1342 	if (!edid)
1343 		return 0;
1344 
1345 	drm_connector_update_edid_property(connector, edid);
1346 	ret = drm_add_edid_modes(connector, edid);
1347 	kfree(edid);
1348 
1349 	return ret;
1350 }
1351 
1352 static struct drm_encoder *
1353 zynqmp_dp_connector_best_encoder(struct drm_connector *connector)
1354 {
1355 	struct zynqmp_dp *dp = connector_to_dp(connector);
1356 
1357 	return &dp->encoder;
1358 }
1359 
1360 static int zynqmp_dp_connector_mode_valid(struct drm_connector *connector,
1361 					  struct drm_display_mode *mode)
1362 {
1363 	struct zynqmp_dp *dp = connector_to_dp(connector);
1364 	u8 max_lanes = dp->link_config.max_lanes;
1365 	u8 bpp = dp->config.bpp;
1366 	int max_rate = dp->link_config.max_rate;
1367 	int rate;
1368 
1369 	if (mode->clock > ZYNQMP_MAX_FREQ) {
1370 		dev_dbg(dp->dev, "filtered the mode, %s,for high pixel rate\n",
1371 			mode->name);
1372 		drm_mode_debug_printmodeline(mode);
1373 		return MODE_CLOCK_HIGH;
1374 	}
1375 
1376 	/* Check with link rate and lane count */
1377 	rate = zynqmp_dp_max_rate(max_rate, max_lanes, bpp);
1378 	if (mode->clock > rate) {
1379 		dev_dbg(dp->dev, "filtered the mode, %s,for high pixel rate\n",
1380 			mode->name);
1381 		drm_mode_debug_printmodeline(mode);
1382 		return MODE_CLOCK_HIGH;
1383 	}
1384 
1385 	return MODE_OK;
1386 }
1387 
1388 static const struct drm_connector_funcs zynqmp_dp_connector_funcs = {
1389 	.detect			= zynqmp_dp_connector_detect,
1390 	.fill_modes		= drm_helper_probe_single_connector_modes,
1391 	.destroy		= drm_connector_cleanup,
1392 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
1393 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
1394 	.reset			= drm_atomic_helper_connector_reset,
1395 };
1396 
1397 static const struct drm_connector_helper_funcs
1398 zynqmp_dp_connector_helper_funcs = {
1399 	.get_modes	= zynqmp_dp_connector_get_modes,
1400 	.best_encoder	= zynqmp_dp_connector_best_encoder,
1401 	.mode_valid	= zynqmp_dp_connector_mode_valid,
1402 };
1403 
1404 /* -----------------------------------------------------------------------------
1405  * DRM Encoder
1406  */
1407 
1408 static void zynqmp_dp_encoder_enable(struct drm_encoder *encoder)
1409 {
1410 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1411 	unsigned int i;
1412 	int ret = 0;
1413 
1414 	pm_runtime_get_sync(dp->dev);
1415 	dp->enabled = true;
1416 	zynqmp_dp_update_misc(dp);
1417 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1418 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 1);
1419 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, 0);
1420 	if (dp->status == connector_status_connected) {
1421 		for (i = 0; i < 3; i++) {
1422 			ret = drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER,
1423 						 DP_SET_POWER_D0);
1424 			if (ret == 1)
1425 				break;
1426 			usleep_range(300, 500);
1427 		}
1428 		/* Some monitors take time to wake up properly */
1429 		msleep(zynqmp_dp_power_on_delay_ms);
1430 	}
1431 	if (ret != 1)
1432 		dev_dbg(dp->dev, "DP aux failed\n");
1433 	else
1434 		zynqmp_dp_train_loop(dp);
1435 	zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET,
1436 			ZYNQMP_DP_SOFTWARE_RESET_ALL);
1437 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1);
1438 }
1439 
1440 static void zynqmp_dp_encoder_disable(struct drm_encoder *encoder)
1441 {
1442 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1443 
1444 	dp->enabled = false;
1445 	cancel_delayed_work(&dp->hpd_work);
1446 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 0);
1447 	drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
1448 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1449 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1450 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1451 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 0);
1452 	pm_runtime_put_sync(dp->dev);
1453 }
1454 
1455 static void
1456 zynqmp_dp_encoder_atomic_mode_set(struct drm_encoder *encoder,
1457 				  struct drm_crtc_state *crtc_state,
1458 				  struct drm_connector_state *connector_state)
1459 {
1460 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1461 	struct drm_display_mode *mode = &crtc_state->mode;
1462 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1463 	u8 max_lanes = dp->link_config.max_lanes;
1464 	u8 bpp = dp->config.bpp;
1465 	int rate, max_rate = dp->link_config.max_rate;
1466 	int ret;
1467 
1468 	zynqmp_dp_set_format(dp, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1469 
1470 	/* Check again as bpp or format might have been chagned */
1471 	rate = zynqmp_dp_max_rate(max_rate, max_lanes, bpp);
1472 	if (mode->clock > rate) {
1473 		dev_err(dp->dev, "the mode, %s,has too high pixel rate\n",
1474 			mode->name);
1475 		drm_mode_debug_printmodeline(mode);
1476 	}
1477 
1478 	ret = zynqmp_dp_mode_configure(dp, adjusted_mode->clock, 0);
1479 	if (ret < 0)
1480 		return;
1481 
1482 	zynqmp_dp_encoder_mode_set_transfer_unit(dp, adjusted_mode);
1483 	zynqmp_dp_encoder_mode_set_stream(dp, adjusted_mode);
1484 }
1485 
1486 #define ZYNQMP_DP_MIN_H_BACKPORCH	20
1487 
1488 static int
1489 zynqmp_dp_encoder_atomic_check(struct drm_encoder *encoder,
1490 			       struct drm_crtc_state *crtc_state,
1491 			       struct drm_connector_state *conn_state)
1492 {
1493 	struct drm_display_mode *mode = &crtc_state->mode;
1494 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1495 	int diff = mode->htotal - mode->hsync_end;
1496 
1497 	/*
1498 	 * ZynqMP DP requires horizontal backporch to be greater than 12.
1499 	 * This limitation may not be compatible with the sink device.
1500 	 */
1501 	if (diff < ZYNQMP_DP_MIN_H_BACKPORCH) {
1502 		int vrefresh = (adjusted_mode->clock * 1000) /
1503 			       (adjusted_mode->vtotal * adjusted_mode->htotal);
1504 
1505 		dev_dbg(encoder->dev->dev, "hbackporch adjusted: %d to %d",
1506 			diff, ZYNQMP_DP_MIN_H_BACKPORCH - diff);
1507 		diff = ZYNQMP_DP_MIN_H_BACKPORCH - diff;
1508 		adjusted_mode->htotal += diff;
1509 		adjusted_mode->clock = adjusted_mode->vtotal *
1510 				       adjusted_mode->htotal * vrefresh / 1000;
1511 	}
1512 
1513 	return 0;
1514 }
1515 
1516 static const struct drm_encoder_helper_funcs zynqmp_dp_encoder_helper_funcs = {
1517 	.enable			= zynqmp_dp_encoder_enable,
1518 	.disable		= zynqmp_dp_encoder_disable,
1519 	.atomic_mode_set	= zynqmp_dp_encoder_atomic_mode_set,
1520 	.atomic_check		= zynqmp_dp_encoder_atomic_check,
1521 };
1522 
1523 /* -----------------------------------------------------------------------------
1524  * Interrupt Handling
1525  */
1526 
1527 /**
1528  * zynqmp_dp_enable_vblank - Enable vblank
1529  * @dp: DisplayPort IP core structure
1530  *
1531  * Enable vblank interrupt
1532  */
1533 void zynqmp_dp_enable_vblank(struct zynqmp_dp *dp)
1534 {
1535 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_VBLANK_START);
1536 }
1537 
1538 /**
1539  * zynqmp_dp_disable_vblank - Disable vblank
1540  * @dp: DisplayPort IP core structure
1541  *
1542  * Disable vblank interrupt
1543  */
1544 void zynqmp_dp_disable_vblank(struct zynqmp_dp *dp)
1545 {
1546 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_VBLANK_START);
1547 }
1548 
1549 static void zynqmp_dp_hpd_work_func(struct work_struct *work)
1550 {
1551 	struct zynqmp_dp *dp;
1552 
1553 	dp = container_of(work, struct zynqmp_dp, hpd_work.work);
1554 
1555 	if (dp->drm)
1556 		drm_helper_hpd_irq_event(dp->drm);
1557 }
1558 
1559 static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
1560 {
1561 	struct zynqmp_dp *dp = (struct zynqmp_dp *)data;
1562 	u32 status, mask;
1563 
1564 	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
1565 	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
1566 	if (!(status & ~mask))
1567 		return IRQ_NONE;
1568 
1569 	/* dbg for diagnostic, but not much that the driver can do */
1570 	if (status & ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK)
1571 		dev_dbg_ratelimited(dp->dev, "underflow interrupt\n");
1572 	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
1573 		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
1574 
1575 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
1576 
1577 	if (status & ZYNQMP_DP_INT_VBLANK_START)
1578 		zynqmp_disp_handle_vblank(dp->dpsub->disp);
1579 
1580 	if (status & ZYNQMP_DP_INT_HPD_EVENT)
1581 		schedule_delayed_work(&dp->hpd_work, 0);
1582 
1583 	if (status & ZYNQMP_DP_INT_HPD_IRQ) {
1584 		int ret;
1585 		u8 status[DP_LINK_STATUS_SIZE + 2];
1586 
1587 		ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
1588 				       DP_LINK_STATUS_SIZE + 2);
1589 		if (ret < 0)
1590 			goto handled;
1591 
1592 		if (status[4] & DP_LINK_STATUS_UPDATED ||
1593 		    !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) ||
1594 		    !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) {
1595 			zynqmp_dp_train_loop(dp);
1596 		}
1597 	}
1598 
1599 handled:
1600 	return IRQ_HANDLED;
1601 }
1602 
1603 /* -----------------------------------------------------------------------------
1604  * Initialization & Cleanup
1605  */
1606 
1607 int zynqmp_dp_drm_init(struct zynqmp_dpsub *dpsub)
1608 {
1609 	struct zynqmp_dp *dp = dpsub->dp;
1610 	struct drm_encoder *encoder = &dp->encoder;
1611 	struct drm_connector *connector = &dp->connector;
1612 	int ret;
1613 
1614 	dp->config.misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK;
1615 	zynqmp_dp_set_format(dp, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1616 
1617 	/* Create the DRM encoder and connector. */
1618 	encoder->possible_crtcs |= zynqmp_disp_get_crtc_mask(dpsub->disp);
1619 	drm_simple_encoder_init(dp->drm, encoder, DRM_MODE_ENCODER_TMDS);
1620 	drm_encoder_helper_add(encoder, &zynqmp_dp_encoder_helper_funcs);
1621 
1622 	connector->polled = DRM_CONNECTOR_POLL_HPD;
1623 	ret = drm_connector_init(encoder->dev, connector,
1624 				 &zynqmp_dp_connector_funcs,
1625 				 DRM_MODE_CONNECTOR_DisplayPort);
1626 	if (ret) {
1627 		dev_err(dp->dev, "failed to create the DRM connector\n");
1628 		return ret;
1629 	}
1630 
1631 	drm_connector_helper_add(connector, &zynqmp_dp_connector_helper_funcs);
1632 	drm_connector_register(connector);
1633 	drm_connector_attach_encoder(connector, encoder);
1634 
1635 	/* Initialize and register the AUX adapter. */
1636 	ret = zynqmp_dp_aux_init(dp);
1637 	if (ret) {
1638 		dev_err(dp->dev, "failed to initialize DP aux\n");
1639 		return ret;
1640 	}
1641 
1642 	/* Now that initialisation is complete, enable interrupts. */
1643 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_ALL);
1644 
1645 	return 0;
1646 }
1647 
1648 int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm)
1649 {
1650 	struct platform_device *pdev = to_platform_device(dpsub->dev);
1651 	struct zynqmp_dp *dp;
1652 	struct resource *res;
1653 	int ret;
1654 
1655 	dp = drmm_kzalloc(drm, sizeof(*dp), GFP_KERNEL);
1656 	if (!dp)
1657 		return -ENOMEM;
1658 
1659 	dp->dev = &pdev->dev;
1660 	dp->dpsub = dpsub;
1661 	dp->status = connector_status_disconnected;
1662 	dp->drm = drm;
1663 
1664 	INIT_DELAYED_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func);
1665 
1666 	dpsub->dp = dp;
1667 
1668 	/* Acquire all resources (IOMEM, IRQ and PHYs). */
1669 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp");
1670 	dp->iomem = devm_ioremap_resource(dp->dev, res);
1671 	if (IS_ERR(dp->iomem))
1672 		return PTR_ERR(dp->iomem);
1673 
1674 	dp->irq = platform_get_irq(pdev, 0);
1675 	if (dp->irq < 0)
1676 		return dp->irq;
1677 
1678 	dp->reset = devm_reset_control_get(dp->dev, NULL);
1679 	if (IS_ERR(dp->reset)) {
1680 		if (PTR_ERR(dp->reset) != -EPROBE_DEFER)
1681 			dev_err(dp->dev, "failed to get reset: %ld\n",
1682 				PTR_ERR(dp->reset));
1683 		return PTR_ERR(dp->reset);
1684 	}
1685 
1686 	ret = zynqmp_dp_phy_probe(dp);
1687 	if (ret)
1688 		return ret;
1689 
1690 	/* Initialize the hardware. */
1691 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1692 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1693 	zynqmp_dp_set(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
1694 	zynqmp_dp_write(dp, ZYNQMP_DP_FORCE_SCRAMBLER_RESET, 1);
1695 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1696 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1697 
1698 	ret = zynqmp_dp_phy_init(dp);
1699 	if (ret)
1700 		return ret;
1701 
1702 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1);
1703 
1704 	/*
1705 	 * Now that the hardware is initialized and won't generate spurious
1706 	 * interrupts, request the IRQ.
1707 	 */
1708 	ret = devm_request_threaded_irq(dp->dev, dp->irq, NULL,
1709 					zynqmp_dp_irq_handler, IRQF_ONESHOT,
1710 					dev_name(dp->dev), dp);
1711 	if (ret < 0)
1712 		goto error;
1713 
1714 	dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n",
1715 		dp->num_lanes);
1716 
1717 	return 0;
1718 
1719 error:
1720 	zynqmp_dp_phy_exit(dp);
1721 	return ret;
1722 }
1723 
1724 void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub)
1725 {
1726 	struct zynqmp_dp *dp = dpsub->dp;
1727 
1728 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL);
1729 	disable_irq(dp->irq);
1730 
1731 	cancel_delayed_work_sync(&dp->hpd_work);
1732 	zynqmp_dp_aux_cleanup(dp);
1733 
1734 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1735 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1736 
1737 	zynqmp_dp_phy_exit(dp);
1738 }
1739