xref: /openbmc/linux/drivers/gpu/drm/xlnx/zynqmp_dp.c (revision 47010c04)
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/dp/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 	zynqmp_dp_clr(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
406 
407 	/*
408 	 * Power on lanes in reverse order as only lane 0 waits for the PLL to
409 	 * lock.
410 	 */
411 	for (i = dp->num_lanes - 1; i >= 0; i--) {
412 		ret = phy_power_on(dp->phy[i]);
413 		if (ret) {
414 			dev_err(dp->dev, "failed to power on phy lane %d\n", i);
415 			return ret;
416 		}
417 	}
418 
419 	return 0;
420 }
421 
422 /**
423  * zynqmp_dp_phy_exit - Exit the phy
424  * @dp: DisplayPort IP core structure
425  *
426  * Exit the phy.
427  */
428 static void zynqmp_dp_phy_exit(struct zynqmp_dp *dp)
429 {
430 	unsigned int i;
431 	int ret;
432 
433 	for (i = 0; i < dp->num_lanes; i++) {
434 		ret = phy_power_off(dp->phy[i]);
435 		if (ret)
436 			dev_err(dp->dev, "failed to power off phy(%d) %d\n", i,
437 				ret);
438 	}
439 
440 	for (i = 0; i < dp->num_lanes; i++) {
441 		ret = phy_exit(dp->phy[i]);
442 		if (ret)
443 			dev_err(dp->dev, "failed to exit phy(%d) %d\n", i, ret);
444 	}
445 }
446 
447 /**
448  * zynqmp_dp_phy_probe - Probe the PHYs
449  * @dp: DisplayPort IP core structure
450  *
451  * Probe PHYs for all lanes. Less PHYs may be available than the number of
452  * lanes, which is not considered an error as long as at least one PHY is
453  * found. The caller can check dp->num_lanes to check how many PHYs were found.
454  *
455  * Return:
456  * * 0				- Success
457  * * -ENXIO			- No PHY found
458  * * -EPROBE_DEFER		- Probe deferral requested
459  * * Other negative value	- PHY retrieval failure
460  */
461 static int zynqmp_dp_phy_probe(struct zynqmp_dp *dp)
462 {
463 	unsigned int i;
464 
465 	for (i = 0; i < ZYNQMP_DP_MAX_LANES; i++) {
466 		char phy_name[16];
467 		struct phy *phy;
468 
469 		snprintf(phy_name, sizeof(phy_name), "dp-phy%d", i);
470 		phy = devm_phy_get(dp->dev, phy_name);
471 
472 		if (IS_ERR(phy)) {
473 			switch (PTR_ERR(phy)) {
474 			case -ENODEV:
475 				if (dp->num_lanes)
476 					return 0;
477 
478 				dev_err(dp->dev, "no PHY found\n");
479 				return -ENXIO;
480 
481 			case -EPROBE_DEFER:
482 				return -EPROBE_DEFER;
483 
484 			default:
485 				dev_err(dp->dev, "failed to get PHY lane %u\n",
486 					i);
487 				return PTR_ERR(phy);
488 			}
489 		}
490 
491 		dp->phy[i] = phy;
492 		dp->num_lanes++;
493 	}
494 
495 	return 0;
496 }
497 
498 /**
499  * zynqmp_dp_phy_ready - Check if PHY is ready
500  * @dp: DisplayPort IP core structure
501  *
502  * Check if PHY is ready. If PHY is not ready, wait 1ms to check for 100 times.
503  * This amount of delay was suggested by IP designer.
504  *
505  * Return: 0 if PHY is ready, or -ENODEV if PHY is not ready.
506  */
507 static int zynqmp_dp_phy_ready(struct zynqmp_dp *dp)
508 {
509 	u32 i, reg, ready;
510 
511 	ready = (1 << dp->num_lanes) - 1;
512 
513 	/* Wait for 100 * 1ms. This should be enough time for PHY to be ready */
514 	for (i = 0; ; i++) {
515 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_PHY_STATUS);
516 		if ((reg & ready) == ready)
517 			return 0;
518 
519 		if (i == 100) {
520 			dev_err(dp->dev, "PHY isn't ready\n");
521 			return -ENODEV;
522 		}
523 
524 		usleep_range(1000, 1100);
525 	}
526 
527 	return 0;
528 }
529 
530 /* -----------------------------------------------------------------------------
531  * DisplayPort Link Training
532  */
533 
534 /**
535  * zynqmp_dp_max_rate - Calculate and return available max pixel clock
536  * @link_rate: link rate (Kilo-bytes / sec)
537  * @lane_num: number of lanes
538  * @bpp: bits per pixel
539  *
540  * Return: max pixel clock (KHz) supported by current link config.
541  */
542 static inline int zynqmp_dp_max_rate(int link_rate, u8 lane_num, u8 bpp)
543 {
544 	return link_rate * lane_num * 8 / bpp;
545 }
546 
547 /**
548  * zynqmp_dp_mode_configure - Configure the link values
549  * @dp: DisplayPort IP core structure
550  * @pclock: pixel clock for requested display mode
551  * @current_bw: current link rate
552  *
553  * Find the link configuration values, rate and lane count for requested pixel
554  * clock @pclock. The @pclock is stored in the mode to be used in other
555  * functions later. The returned rate is downshifted from the current rate
556  * @current_bw.
557  *
558  * Return: Current link rate code, or -EINVAL.
559  */
560 static int zynqmp_dp_mode_configure(struct zynqmp_dp *dp, int pclock,
561 				    u8 current_bw)
562 {
563 	int max_rate = dp->link_config.max_rate;
564 	u8 bw_code;
565 	u8 max_lanes = dp->link_config.max_lanes;
566 	u8 max_link_rate_code = drm_dp_link_rate_to_bw_code(max_rate);
567 	u8 bpp = dp->config.bpp;
568 	u8 lane_cnt;
569 
570 	/* Downshift from current bandwidth */
571 	switch (current_bw) {
572 	case DP_LINK_BW_5_4:
573 		bw_code = DP_LINK_BW_2_7;
574 		break;
575 	case DP_LINK_BW_2_7:
576 		bw_code = DP_LINK_BW_1_62;
577 		break;
578 	case DP_LINK_BW_1_62:
579 		dev_err(dp->dev, "can't downshift. already lowest link rate\n");
580 		return -EINVAL;
581 	default:
582 		/* If not given, start with max supported */
583 		bw_code = max_link_rate_code;
584 		break;
585 	}
586 
587 	for (lane_cnt = 1; lane_cnt <= max_lanes; lane_cnt <<= 1) {
588 		int bw;
589 		u32 rate;
590 
591 		bw = drm_dp_bw_code_to_link_rate(bw_code);
592 		rate = zynqmp_dp_max_rate(bw, lane_cnt, bpp);
593 		if (pclock <= rate) {
594 			dp->mode.bw_code = bw_code;
595 			dp->mode.lane_cnt = lane_cnt;
596 			dp->mode.pclock = pclock;
597 			return dp->mode.bw_code;
598 		}
599 	}
600 
601 	dev_err(dp->dev, "failed to configure link values\n");
602 
603 	return -EINVAL;
604 }
605 
606 /**
607  * zynqmp_dp_adjust_train - Adjust train values
608  * @dp: DisplayPort IP core structure
609  * @link_status: link status from sink which contains requested training values
610  */
611 static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp,
612 				   u8 link_status[DP_LINK_STATUS_SIZE])
613 {
614 	u8 *train_set = dp->train_set;
615 	u8 voltage = 0, preemphasis = 0;
616 	u8 i;
617 
618 	for (i = 0; i < dp->mode.lane_cnt; i++) {
619 		u8 v = drm_dp_get_adjust_request_voltage(link_status, i);
620 		u8 p = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
621 
622 		if (v > voltage)
623 			voltage = v;
624 
625 		if (p > preemphasis)
626 			preemphasis = p;
627 	}
628 
629 	if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3)
630 		voltage |= DP_TRAIN_MAX_SWING_REACHED;
631 
632 	if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2)
633 		preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
634 
635 	for (i = 0; i < dp->mode.lane_cnt; i++)
636 		train_set[i] = voltage | preemphasis;
637 }
638 
639 /**
640  * zynqmp_dp_update_vs_emph - Update the training values
641  * @dp: DisplayPort IP core structure
642  *
643  * Update the training values based on the request from sink. The mapped values
644  * are predefined, and values(vs, pe, pc) are from the device manual.
645  *
646  * Return: 0 if vs and emph are updated successfully, or the error code returned
647  * by drm_dp_dpcd_write().
648  */
649 static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
650 {
651 	unsigned int i;
652 	int ret;
653 
654 	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->train_set,
655 				dp->mode.lane_cnt);
656 	if (ret < 0)
657 		return ret;
658 
659 	for (i = 0; i < dp->mode.lane_cnt; i++) {
660 		u32 reg = ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0 + i * 4;
661 		union phy_configure_opts opts = { 0 };
662 		u8 train = dp->train_set[i];
663 
664 		opts.dp.voltage[0] = (train & DP_TRAIN_VOLTAGE_SWING_MASK)
665 				   >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
666 		opts.dp.pre[0] = (train & DP_TRAIN_PRE_EMPHASIS_MASK)
667 			       >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
668 
669 		phy_configure(dp->phy[i], &opts);
670 
671 		zynqmp_dp_write(dp, reg, 0x2);
672 	}
673 
674 	return 0;
675 }
676 
677 /**
678  * zynqmp_dp_link_train_cr - Train clock recovery
679  * @dp: DisplayPort IP core structure
680  *
681  * Return: 0 if clock recovery train is done successfully, or corresponding
682  * error code.
683  */
684 static int zynqmp_dp_link_train_cr(struct zynqmp_dp *dp)
685 {
686 	u8 link_status[DP_LINK_STATUS_SIZE];
687 	u8 lane_cnt = dp->mode.lane_cnt;
688 	u8 vs = 0, tries = 0;
689 	u16 max_tries, i;
690 	bool cr_done;
691 	int ret;
692 
693 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
694 			DP_TRAINING_PATTERN_1);
695 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
696 				 DP_TRAINING_PATTERN_1 |
697 				 DP_LINK_SCRAMBLING_DISABLE);
698 	if (ret < 0)
699 		return ret;
700 
701 	/*
702 	 * 256 loops should be maximum iterations for 4 lanes and 4 values.
703 	 * So, This loop should exit before 512 iterations
704 	 */
705 	for (max_tries = 0; max_tries < 512; max_tries++) {
706 		ret = zynqmp_dp_update_vs_emph(dp);
707 		if (ret)
708 			return ret;
709 
710 		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
711 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
712 		if (ret < 0)
713 			return ret;
714 
715 		cr_done = drm_dp_clock_recovery_ok(link_status, lane_cnt);
716 		if (cr_done)
717 			break;
718 
719 		for (i = 0; i < lane_cnt; i++)
720 			if (!(dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED))
721 				break;
722 		if (i == lane_cnt)
723 			break;
724 
725 		if ((dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == vs)
726 			tries++;
727 		else
728 			tries = 0;
729 
730 		if (tries == DP_MAX_TRAINING_TRIES)
731 			break;
732 
733 		vs = dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
734 		zynqmp_dp_adjust_train(dp, link_status);
735 	}
736 
737 	if (!cr_done)
738 		return -EIO;
739 
740 	return 0;
741 }
742 
743 /**
744  * zynqmp_dp_link_train_ce - Train channel equalization
745  * @dp: DisplayPort IP core structure
746  *
747  * Return: 0 if channel equalization train is done successfully, or
748  * corresponding error code.
749  */
750 static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
751 {
752 	u8 link_status[DP_LINK_STATUS_SIZE];
753 	u8 lane_cnt = dp->mode.lane_cnt;
754 	u32 pat, tries;
755 	int ret;
756 	bool ce_done;
757 
758 	if (dp->dpcd[DP_DPCD_REV] >= DP_V1_2 &&
759 	    dp->dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED)
760 		pat = DP_TRAINING_PATTERN_3;
761 	else
762 		pat = DP_TRAINING_PATTERN_2;
763 
764 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET, pat);
765 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
766 				 pat | DP_LINK_SCRAMBLING_DISABLE);
767 	if (ret < 0)
768 		return ret;
769 
770 	for (tries = 0; tries < DP_MAX_TRAINING_TRIES; tries++) {
771 		ret = zynqmp_dp_update_vs_emph(dp);
772 		if (ret)
773 			return ret;
774 
775 		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
776 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
777 		if (ret < 0)
778 			return ret;
779 
780 		ce_done = drm_dp_channel_eq_ok(link_status, lane_cnt);
781 		if (ce_done)
782 			break;
783 
784 		zynqmp_dp_adjust_train(dp, link_status);
785 	}
786 
787 	if (!ce_done)
788 		return -EIO;
789 
790 	return 0;
791 }
792 
793 /**
794  * zynqmp_dp_link_train - Train the link
795  * @dp: DisplayPort IP core structure
796  *
797  * Return: 0 if all trains are done successfully, or corresponding error code.
798  */
799 static int zynqmp_dp_train(struct zynqmp_dp *dp)
800 {
801 	u32 reg;
802 	u8 bw_code = dp->mode.bw_code;
803 	u8 lane_cnt = dp->mode.lane_cnt;
804 	u8 aux_lane_cnt = lane_cnt;
805 	bool enhanced;
806 	int ret;
807 
808 	zynqmp_dp_write(dp, ZYNQMP_DP_LANE_COUNT_SET, lane_cnt);
809 	enhanced = drm_dp_enhanced_frame_cap(dp->dpcd);
810 	if (enhanced) {
811 		zynqmp_dp_write(dp, ZYNQMP_DP_ENHANCED_FRAME_EN, 1);
812 		aux_lane_cnt |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
813 	}
814 
815 	if (dp->dpcd[3] & 0x1) {
816 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 1);
817 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL,
818 				   DP_SPREAD_AMP_0_5);
819 	} else {
820 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 0);
821 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL, 0);
822 	}
823 
824 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET, aux_lane_cnt);
825 	if (ret < 0) {
826 		dev_err(dp->dev, "failed to set lane count\n");
827 		return ret;
828 	}
829 
830 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
831 				 DP_SET_ANSI_8B10B);
832 	if (ret < 0) {
833 		dev_err(dp->dev, "failed to set ANSI 8B/10B encoding\n");
834 		return ret;
835 	}
836 
837 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LINK_BW_SET, bw_code);
838 	if (ret < 0) {
839 		dev_err(dp->dev, "failed to set DP bandwidth\n");
840 		return ret;
841 	}
842 
843 	zynqmp_dp_write(dp, ZYNQMP_DP_LINK_BW_SET, bw_code);
844 	switch (bw_code) {
845 	case DP_LINK_BW_1_62:
846 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G;
847 		break;
848 	case DP_LINK_BW_2_7:
849 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G;
850 		break;
851 	case DP_LINK_BW_5_4:
852 	default:
853 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G;
854 		break;
855 	}
856 
857 	zynqmp_dp_write(dp, ZYNQMP_DP_PHY_CLOCK_SELECT, reg);
858 	ret = zynqmp_dp_phy_ready(dp);
859 	if (ret < 0)
860 		return ret;
861 
862 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 1);
863 	memset(dp->train_set, 0, sizeof(dp->train_set));
864 	ret = zynqmp_dp_link_train_cr(dp);
865 	if (ret)
866 		return ret;
867 
868 	ret = zynqmp_dp_link_train_ce(dp);
869 	if (ret)
870 		return ret;
871 
872 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
873 				 DP_TRAINING_PATTERN_DISABLE);
874 	if (ret < 0) {
875 		dev_err(dp->dev, "failed to disable training pattern\n");
876 		return ret;
877 	}
878 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
879 			DP_TRAINING_PATTERN_DISABLE);
880 
881 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 0);
882 
883 	return 0;
884 }
885 
886 /**
887  * zynqmp_dp_train_loop - Downshift the link rate during training
888  * @dp: DisplayPort IP core structure
889  *
890  * Train the link by downshifting the link rate if training is not successful.
891  */
892 static void zynqmp_dp_train_loop(struct zynqmp_dp *dp)
893 {
894 	struct zynqmp_dp_mode *mode = &dp->mode;
895 	u8 bw = mode->bw_code;
896 	int ret;
897 
898 	do {
899 		if (dp->status == connector_status_disconnected ||
900 		    !dp->enabled)
901 			return;
902 
903 		ret = zynqmp_dp_train(dp);
904 		if (!ret)
905 			return;
906 
907 		ret = zynqmp_dp_mode_configure(dp, mode->pclock, bw);
908 		if (ret < 0)
909 			goto err_out;
910 
911 		bw = ret;
912 	} while (bw >= DP_LINK_BW_1_62);
913 
914 err_out:
915 	dev_err(dp->dev, "failed to train the DP link\n");
916 }
917 
918 /* -----------------------------------------------------------------------------
919  * DisplayPort AUX
920  */
921 
922 #define AUX_READ_BIT	0x1
923 
924 /**
925  * zynqmp_dp_aux_cmd_submit - Submit aux command
926  * @dp: DisplayPort IP core structure
927  * @cmd: aux command
928  * @addr: aux address
929  * @buf: buffer for command data
930  * @bytes: number of bytes for @buf
931  * @reply: reply code to be returned
932  *
933  * Submit an aux command. All aux related commands, native or i2c aux
934  * read/write, are submitted through this function. The function is mapped to
935  * the transfer function of struct drm_dp_aux. This function involves in
936  * multiple register reads/writes, thus synchronization is needed, and it is
937  * done by drm_dp_helper using @hw_mutex. The calling thread goes into sleep
938  * if there's no immediate reply to the command submission. The reply code is
939  * returned at @reply if @reply != NULL.
940  *
941  * Return: 0 if the command is submitted properly, or corresponding error code:
942  * -EBUSY when there is any request already being processed
943  * -ETIMEDOUT when receiving reply is timed out
944  * -EIO when received bytes are less than requested
945  */
946 static int zynqmp_dp_aux_cmd_submit(struct zynqmp_dp *dp, u32 cmd, u16 addr,
947 				    u8 *buf, u8 bytes, u8 *reply)
948 {
949 	bool is_read = (cmd & AUX_READ_BIT) ? true : false;
950 	u32 reg, i;
951 
952 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
953 	if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST)
954 		return -EBUSY;
955 
956 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_ADDRESS, addr);
957 	if (!is_read)
958 		for (i = 0; i < bytes; i++)
959 			zynqmp_dp_write(dp, ZYNQMP_DP_AUX_WRITE_FIFO,
960 					buf[i]);
961 
962 	reg = cmd << ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT;
963 	if (!buf || !bytes)
964 		reg |= ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY;
965 	else
966 		reg |= (bytes - 1) << ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT;
967 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_COMMAND, reg);
968 
969 	/* Wait for reply to be delivered upto 2ms */
970 	for (i = 0; ; i++) {
971 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
972 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY)
973 			break;
974 
975 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT ||
976 		    i == 2)
977 			return -ETIMEDOUT;
978 
979 		usleep_range(1000, 1100);
980 	}
981 
982 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_CODE);
983 	if (reply)
984 		*reply = reg;
985 
986 	if (is_read &&
987 	    (reg == ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK ||
988 	     reg == ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK)) {
989 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_REPLY_DATA_COUNT);
990 		if ((reg & ZYNQMP_DP_REPLY_DATA_COUNT_MASK) != bytes)
991 			return -EIO;
992 
993 		for (i = 0; i < bytes; i++)
994 			buf[i] = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_DATA);
995 	}
996 
997 	return 0;
998 }
999 
1000 static ssize_t
1001 zynqmp_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
1002 {
1003 	struct zynqmp_dp *dp = container_of(aux, struct zynqmp_dp, aux);
1004 	int ret;
1005 	unsigned int i, iter;
1006 
1007 	/* Number of loops = timeout in msec / aux delay (400 usec) */
1008 	iter = zynqmp_dp_aux_timeout_ms * 1000 / 400;
1009 	iter = iter ? iter : 1;
1010 
1011 	for (i = 0; i < iter; i++) {
1012 		ret = zynqmp_dp_aux_cmd_submit(dp, msg->request, msg->address,
1013 					       msg->buffer, msg->size,
1014 					       &msg->reply);
1015 		if (!ret) {
1016 			dev_dbg(dp->dev, "aux %d retries\n", i);
1017 			return msg->size;
1018 		}
1019 
1020 		if (dp->status == connector_status_disconnected) {
1021 			dev_dbg(dp->dev, "no connected aux device\n");
1022 			return -ENODEV;
1023 		}
1024 
1025 		usleep_range(400, 500);
1026 	}
1027 
1028 	dev_dbg(dp->dev, "failed to do aux transfer (%d)\n", ret);
1029 
1030 	return ret;
1031 }
1032 
1033 /**
1034  * zynqmp_dp_aux_init - Initialize and register the DP AUX
1035  * @dp: DisplayPort IP core structure
1036  *
1037  * Program the AUX clock divider and filter and register the DP AUX adapter.
1038  *
1039  * Return: 0 on success, error value otherwise
1040  */
1041 static int zynqmp_dp_aux_init(struct zynqmp_dp *dp)
1042 {
1043 	unsigned long rate;
1044 	unsigned int w;
1045 
1046 	/*
1047 	 * The AUX_SIGNAL_WIDTH_FILTER is the number of APB clock cycles
1048 	 * corresponding to the AUX pulse. Allowable values are 8, 16, 24, 32,
1049 	 * 40 and 48. The AUX pulse width must be between 0.4µs and 0.6µs,
1050 	 * compute the w / 8 value corresponding to 0.4µs rounded up, and make
1051 	 * sure it stays below 0.6µs and within the allowable values.
1052 	 */
1053 	rate = clk_get_rate(dp->dpsub->apb_clk);
1054 	w = DIV_ROUND_UP(4 * rate, 1000 * 1000 * 10 * 8) * 8;
1055 	if (w > 6 * rate / (1000 * 1000 * 10) || w > 48) {
1056 		dev_err(dp->dev, "aclk frequency too high\n");
1057 		return -EINVAL;
1058 	}
1059 
1060 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_CLK_DIVIDER,
1061 			(w << ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT) |
1062 			(rate / (1000 * 1000)));
1063 
1064 	dp->aux.name = "ZynqMP DP AUX";
1065 	dp->aux.dev = dp->dev;
1066 	dp->aux.drm_dev = dp->drm;
1067 	dp->aux.transfer = zynqmp_dp_aux_transfer;
1068 
1069 	return drm_dp_aux_register(&dp->aux);
1070 }
1071 
1072 /**
1073  * zynqmp_dp_aux_cleanup - Cleanup the DP AUX
1074  * @dp: DisplayPort IP core structure
1075  *
1076  * Unregister the DP AUX adapter.
1077  */
1078 static void zynqmp_dp_aux_cleanup(struct zynqmp_dp *dp)
1079 {
1080 	drm_dp_aux_unregister(&dp->aux);
1081 }
1082 
1083 /* -----------------------------------------------------------------------------
1084  * DisplayPort Generic Support
1085  */
1086 
1087 /**
1088  * zynqmp_dp_update_misc - Write the misc registers
1089  * @dp: DisplayPort IP core structure
1090  *
1091  * The misc register values are stored in the structure, and this
1092  * function applies the values into the registers.
1093  */
1094 static void zynqmp_dp_update_misc(struct zynqmp_dp *dp)
1095 {
1096 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC0, dp->config.misc0);
1097 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC1, dp->config.misc1);
1098 }
1099 
1100 /**
1101  * zynqmp_dp_set_format - Set the input format
1102  * @dp: DisplayPort IP core structure
1103  * @format: input format
1104  * @bpc: bits per component
1105  *
1106  * Update misc register values based on input @format and @bpc.
1107  *
1108  * Return: 0 on success, or -EINVAL.
1109  */
1110 static int zynqmp_dp_set_format(struct zynqmp_dp *dp,
1111 				enum zynqmp_dpsub_format format,
1112 				unsigned int bpc)
1113 {
1114 	static const struct drm_display_info *display;
1115 	struct zynqmp_dp_config *config = &dp->config;
1116 	unsigned int num_colors;
1117 
1118 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK;
1119 	config->misc1 &= ~ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1120 
1121 	switch (format) {
1122 	case ZYNQMP_DPSUB_FORMAT_RGB:
1123 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB;
1124 		num_colors = 3;
1125 		break;
1126 
1127 	case ZYNQMP_DPSUB_FORMAT_YCRCB444:
1128 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444;
1129 		num_colors = 3;
1130 		break;
1131 
1132 	case ZYNQMP_DPSUB_FORMAT_YCRCB422:
1133 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422;
1134 		num_colors = 2;
1135 		break;
1136 
1137 	case ZYNQMP_DPSUB_FORMAT_YONLY:
1138 		config->misc1 |= ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1139 		num_colors = 1;
1140 		break;
1141 
1142 	default:
1143 		dev_err(dp->dev, "Invalid colormetry in DT\n");
1144 		return -EINVAL;
1145 	}
1146 
1147 	display = &dp->connector.display_info;
1148 	if (display->bpc && bpc > display->bpc) {
1149 		dev_warn(dp->dev,
1150 			 "downgrading requested %ubpc to display limit %ubpc\n",
1151 			 bpc, display->bpc);
1152 		bpc = display->bpc;
1153 	}
1154 
1155 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK;
1156 
1157 	switch (bpc) {
1158 	case 6:
1159 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6;
1160 		break;
1161 	case 8:
1162 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1163 		break;
1164 	case 10:
1165 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10;
1166 		break;
1167 	case 12:
1168 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12;
1169 		break;
1170 	case 16:
1171 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16;
1172 		break;
1173 	default:
1174 		dev_warn(dp->dev, "Not supported bpc (%u). fall back to 8bpc\n",
1175 			 bpc);
1176 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1177 		bpc = 8;
1178 		break;
1179 	}
1180 
1181 	/* Update the current bpp based on the format. */
1182 	config->bpp = bpc * num_colors;
1183 
1184 	return 0;
1185 }
1186 
1187 /**
1188  * zynqmp_dp_encoder_mode_set_transfer_unit - Set the transfer unit values
1189  * @dp: DisplayPort IP core structure
1190  * @mode: requested display mode
1191  *
1192  * Set the transfer unit, and calculate all transfer unit size related values.
1193  * Calculation is based on DP and IP core specification.
1194  */
1195 static void
1196 zynqmp_dp_encoder_mode_set_transfer_unit(struct zynqmp_dp *dp,
1197 					 struct drm_display_mode *mode)
1198 {
1199 	u32 tu = ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF;
1200 	u32 bw, vid_kbytes, avg_bytes_per_tu, init_wait;
1201 
1202 	/* Use the max transfer unit size (default) */
1203 	zynqmp_dp_write(dp, ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE, tu);
1204 
1205 	vid_kbytes = mode->clock * (dp->config.bpp / 8);
1206 	bw = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1207 	avg_bytes_per_tu = vid_kbytes * tu / (dp->mode.lane_cnt * bw / 1000);
1208 	zynqmp_dp_write(dp, ZYNQMP_DP_MIN_BYTES_PER_TU,
1209 			avg_bytes_per_tu / 1000);
1210 	zynqmp_dp_write(dp, ZYNQMP_DP_FRAC_BYTES_PER_TU,
1211 			avg_bytes_per_tu % 1000);
1212 
1213 	/* Configure the initial wait cycle based on transfer unit size */
1214 	if (tu < (avg_bytes_per_tu / 1000))
1215 		init_wait = 0;
1216 	else if ((avg_bytes_per_tu / 1000) <= 4)
1217 		init_wait = tu;
1218 	else
1219 		init_wait = tu - avg_bytes_per_tu / 1000;
1220 
1221 	zynqmp_dp_write(dp, ZYNQMP_DP_INIT_WAIT, init_wait);
1222 }
1223 
1224 /**
1225  * zynqmp_dp_encoder_mode_set_stream - Configure the main stream
1226  * @dp: DisplayPort IP core structure
1227  * @mode: requested display mode
1228  *
1229  * Configure the main stream based on the requested mode @mode. Calculation is
1230  * based on IP core specification.
1231  */
1232 static void zynqmp_dp_encoder_mode_set_stream(struct zynqmp_dp *dp,
1233 					      const struct drm_display_mode *mode)
1234 {
1235 	u8 lane_cnt = dp->mode.lane_cnt;
1236 	u32 reg, wpl;
1237 	unsigned int rate;
1238 
1239 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HTOTAL, mode->htotal);
1240 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VTOTAL, mode->vtotal);
1241 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_POLARITY,
1242 			(!!(mode->flags & DRM_MODE_FLAG_PVSYNC) <<
1243 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT) |
1244 			(!!(mode->flags & DRM_MODE_FLAG_PHSYNC) <<
1245 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT));
1246 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSWIDTH,
1247 			mode->hsync_end - mode->hsync_start);
1248 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSWIDTH,
1249 			mode->vsync_end - mode->vsync_start);
1250 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HRES, mode->hdisplay);
1251 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VRES, mode->vdisplay);
1252 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSTART,
1253 			mode->htotal - mode->hsync_start);
1254 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSTART,
1255 			mode->vtotal - mode->vsync_start);
1256 
1257 	/* In synchronous mode, set the diviers */
1258 	if (dp->config.misc0 & ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK) {
1259 		reg = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1260 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_N_VID, reg);
1261 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_M_VID, mode->clock);
1262 		rate = zynqmp_disp_get_audio_clk_rate(dp->dpsub->disp);
1263 		if (rate) {
1264 			dev_dbg(dp->dev, "Audio rate: %d\n", rate / 512);
1265 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_N_AUD, reg);
1266 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_M_AUD, rate / 1000);
1267 		}
1268 	}
1269 
1270 	/* Only 2 channel audio is supported now */
1271 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1272 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CHANNELS, 1);
1273 
1274 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_PIX_WIDTH, 1);
1275 
1276 	/* Translate to the native 16 bit datapath based on IP core spec */
1277 	wpl = (mode->hdisplay * dp->config.bpp + 15) / 16;
1278 	reg = wpl + wpl % lane_cnt - lane_cnt;
1279 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_DATA_COUNT_PER_LANE, reg);
1280 }
1281 
1282 /* -----------------------------------------------------------------------------
1283  * DRM Connector
1284  */
1285 
1286 static enum drm_connector_status
1287 zynqmp_dp_connector_detect(struct drm_connector *connector, bool force)
1288 {
1289 	struct zynqmp_dp *dp = connector_to_dp(connector);
1290 	struct zynqmp_dp_link_config *link_config = &dp->link_config;
1291 	u32 state, i;
1292 	int ret;
1293 
1294 	/*
1295 	 * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to
1296 	 * get the HPD signal with some monitors.
1297 	 */
1298 	for (i = 0; i < 10; i++) {
1299 		state = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
1300 		if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD)
1301 			break;
1302 		msleep(100);
1303 	}
1304 
1305 	if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD) {
1306 		ret = drm_dp_dpcd_read(&dp->aux, 0x0, dp->dpcd,
1307 				       sizeof(dp->dpcd));
1308 		if (ret < 0) {
1309 			dev_dbg(dp->dev, "DPCD read failed");
1310 			goto disconnected;
1311 		}
1312 
1313 		link_config->max_rate = min_t(int,
1314 					      drm_dp_max_link_rate(dp->dpcd),
1315 					      DP_HIGH_BIT_RATE2);
1316 		link_config->max_lanes = min_t(u8,
1317 					       drm_dp_max_lane_count(dp->dpcd),
1318 					       dp->num_lanes);
1319 
1320 		dp->status = connector_status_connected;
1321 		return connector_status_connected;
1322 	}
1323 
1324 disconnected:
1325 	dp->status = connector_status_disconnected;
1326 	return connector_status_disconnected;
1327 }
1328 
1329 static int zynqmp_dp_connector_get_modes(struct drm_connector *connector)
1330 {
1331 	struct zynqmp_dp *dp = connector_to_dp(connector);
1332 	struct edid *edid;
1333 	int ret;
1334 
1335 	edid = drm_get_edid(connector, &dp->aux.ddc);
1336 	if (!edid)
1337 		return 0;
1338 
1339 	drm_connector_update_edid_property(connector, edid);
1340 	ret = drm_add_edid_modes(connector, edid);
1341 	kfree(edid);
1342 
1343 	return ret;
1344 }
1345 
1346 static struct drm_encoder *
1347 zynqmp_dp_connector_best_encoder(struct drm_connector *connector)
1348 {
1349 	struct zynqmp_dp *dp = connector_to_dp(connector);
1350 
1351 	return &dp->encoder;
1352 }
1353 
1354 static int zynqmp_dp_connector_mode_valid(struct drm_connector *connector,
1355 					  struct drm_display_mode *mode)
1356 {
1357 	struct zynqmp_dp *dp = connector_to_dp(connector);
1358 	u8 max_lanes = dp->link_config.max_lanes;
1359 	u8 bpp = dp->config.bpp;
1360 	int max_rate = dp->link_config.max_rate;
1361 	int rate;
1362 
1363 	if (mode->clock > ZYNQMP_MAX_FREQ) {
1364 		dev_dbg(dp->dev, "filtered the mode, %s,for high pixel rate\n",
1365 			mode->name);
1366 		drm_mode_debug_printmodeline(mode);
1367 		return MODE_CLOCK_HIGH;
1368 	}
1369 
1370 	/* Check with link rate and lane count */
1371 	rate = zynqmp_dp_max_rate(max_rate, max_lanes, bpp);
1372 	if (mode->clock > rate) {
1373 		dev_dbg(dp->dev, "filtered the mode, %s,for high pixel rate\n",
1374 			mode->name);
1375 		drm_mode_debug_printmodeline(mode);
1376 		return MODE_CLOCK_HIGH;
1377 	}
1378 
1379 	return MODE_OK;
1380 }
1381 
1382 static const struct drm_connector_funcs zynqmp_dp_connector_funcs = {
1383 	.detect			= zynqmp_dp_connector_detect,
1384 	.fill_modes		= drm_helper_probe_single_connector_modes,
1385 	.destroy		= drm_connector_cleanup,
1386 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
1387 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
1388 	.reset			= drm_atomic_helper_connector_reset,
1389 };
1390 
1391 static const struct drm_connector_helper_funcs
1392 zynqmp_dp_connector_helper_funcs = {
1393 	.get_modes	= zynqmp_dp_connector_get_modes,
1394 	.best_encoder	= zynqmp_dp_connector_best_encoder,
1395 	.mode_valid	= zynqmp_dp_connector_mode_valid,
1396 };
1397 
1398 /* -----------------------------------------------------------------------------
1399  * DRM Encoder
1400  */
1401 
1402 static void zynqmp_dp_encoder_enable(struct drm_encoder *encoder)
1403 {
1404 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1405 	unsigned int i;
1406 	int ret = 0;
1407 
1408 	pm_runtime_get_sync(dp->dev);
1409 	dp->enabled = true;
1410 	zynqmp_dp_update_misc(dp);
1411 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1412 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 1);
1413 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, 0);
1414 	if (dp->status == connector_status_connected) {
1415 		for (i = 0; i < 3; i++) {
1416 			ret = drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER,
1417 						 DP_SET_POWER_D0);
1418 			if (ret == 1)
1419 				break;
1420 			usleep_range(300, 500);
1421 		}
1422 		/* Some monitors take time to wake up properly */
1423 		msleep(zynqmp_dp_power_on_delay_ms);
1424 	}
1425 	if (ret != 1)
1426 		dev_dbg(dp->dev, "DP aux failed\n");
1427 	else
1428 		zynqmp_dp_train_loop(dp);
1429 	zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET,
1430 			ZYNQMP_DP_SOFTWARE_RESET_ALL);
1431 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1);
1432 }
1433 
1434 static void zynqmp_dp_encoder_disable(struct drm_encoder *encoder)
1435 {
1436 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1437 
1438 	dp->enabled = false;
1439 	cancel_delayed_work(&dp->hpd_work);
1440 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 0);
1441 	drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
1442 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1443 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1444 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1445 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 0);
1446 	pm_runtime_put_sync(dp->dev);
1447 }
1448 
1449 static void
1450 zynqmp_dp_encoder_atomic_mode_set(struct drm_encoder *encoder,
1451 				  struct drm_crtc_state *crtc_state,
1452 				  struct drm_connector_state *connector_state)
1453 {
1454 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1455 	struct drm_display_mode *mode = &crtc_state->mode;
1456 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1457 	u8 max_lanes = dp->link_config.max_lanes;
1458 	u8 bpp = dp->config.bpp;
1459 	int rate, max_rate = dp->link_config.max_rate;
1460 	int ret;
1461 
1462 	zynqmp_dp_set_format(dp, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1463 
1464 	/* Check again as bpp or format might have been chagned */
1465 	rate = zynqmp_dp_max_rate(max_rate, max_lanes, bpp);
1466 	if (mode->clock > rate) {
1467 		dev_err(dp->dev, "the mode, %s,has too high pixel rate\n",
1468 			mode->name);
1469 		drm_mode_debug_printmodeline(mode);
1470 	}
1471 
1472 	ret = zynqmp_dp_mode_configure(dp, adjusted_mode->clock, 0);
1473 	if (ret < 0)
1474 		return;
1475 
1476 	zynqmp_dp_encoder_mode_set_transfer_unit(dp, adjusted_mode);
1477 	zynqmp_dp_encoder_mode_set_stream(dp, adjusted_mode);
1478 }
1479 
1480 #define ZYNQMP_DP_MIN_H_BACKPORCH	20
1481 
1482 static int
1483 zynqmp_dp_encoder_atomic_check(struct drm_encoder *encoder,
1484 			       struct drm_crtc_state *crtc_state,
1485 			       struct drm_connector_state *conn_state)
1486 {
1487 	struct drm_display_mode *mode = &crtc_state->mode;
1488 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1489 	int diff = mode->htotal - mode->hsync_end;
1490 
1491 	/*
1492 	 * ZynqMP DP requires horizontal backporch to be greater than 12.
1493 	 * This limitation may not be compatible with the sink device.
1494 	 */
1495 	if (diff < ZYNQMP_DP_MIN_H_BACKPORCH) {
1496 		int vrefresh = (adjusted_mode->clock * 1000) /
1497 			       (adjusted_mode->vtotal * adjusted_mode->htotal);
1498 
1499 		dev_dbg(encoder->dev->dev, "hbackporch adjusted: %d to %d",
1500 			diff, ZYNQMP_DP_MIN_H_BACKPORCH - diff);
1501 		diff = ZYNQMP_DP_MIN_H_BACKPORCH - diff;
1502 		adjusted_mode->htotal += diff;
1503 		adjusted_mode->clock = adjusted_mode->vtotal *
1504 				       adjusted_mode->htotal * vrefresh / 1000;
1505 	}
1506 
1507 	return 0;
1508 }
1509 
1510 static const struct drm_encoder_helper_funcs zynqmp_dp_encoder_helper_funcs = {
1511 	.enable			= zynqmp_dp_encoder_enable,
1512 	.disable		= zynqmp_dp_encoder_disable,
1513 	.atomic_mode_set	= zynqmp_dp_encoder_atomic_mode_set,
1514 	.atomic_check		= zynqmp_dp_encoder_atomic_check,
1515 };
1516 
1517 /* -----------------------------------------------------------------------------
1518  * Interrupt Handling
1519  */
1520 
1521 /**
1522  * zynqmp_dp_enable_vblank - Enable vblank
1523  * @dp: DisplayPort IP core structure
1524  *
1525  * Enable vblank interrupt
1526  */
1527 void zynqmp_dp_enable_vblank(struct zynqmp_dp *dp)
1528 {
1529 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_VBLANK_START);
1530 }
1531 
1532 /**
1533  * zynqmp_dp_disable_vblank - Disable vblank
1534  * @dp: DisplayPort IP core structure
1535  *
1536  * Disable vblank interrupt
1537  */
1538 void zynqmp_dp_disable_vblank(struct zynqmp_dp *dp)
1539 {
1540 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_VBLANK_START);
1541 }
1542 
1543 static void zynqmp_dp_hpd_work_func(struct work_struct *work)
1544 {
1545 	struct zynqmp_dp *dp;
1546 
1547 	dp = container_of(work, struct zynqmp_dp, hpd_work.work);
1548 
1549 	if (dp->drm)
1550 		drm_helper_hpd_irq_event(dp->drm);
1551 }
1552 
1553 static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
1554 {
1555 	struct zynqmp_dp *dp = (struct zynqmp_dp *)data;
1556 	u32 status, mask;
1557 
1558 	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
1559 	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
1560 	if (!(status & ~mask))
1561 		return IRQ_NONE;
1562 
1563 	/* dbg for diagnostic, but not much that the driver can do */
1564 	if (status & ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK)
1565 		dev_dbg_ratelimited(dp->dev, "underflow interrupt\n");
1566 	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
1567 		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
1568 
1569 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
1570 
1571 	if (status & ZYNQMP_DP_INT_VBLANK_START)
1572 		zynqmp_disp_handle_vblank(dp->dpsub->disp);
1573 
1574 	if (status & ZYNQMP_DP_INT_HPD_EVENT)
1575 		schedule_delayed_work(&dp->hpd_work, 0);
1576 
1577 	if (status & ZYNQMP_DP_INT_HPD_IRQ) {
1578 		int ret;
1579 		u8 status[DP_LINK_STATUS_SIZE + 2];
1580 
1581 		ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
1582 				       DP_LINK_STATUS_SIZE + 2);
1583 		if (ret < 0)
1584 			goto handled;
1585 
1586 		if (status[4] & DP_LINK_STATUS_UPDATED ||
1587 		    !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) ||
1588 		    !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) {
1589 			zynqmp_dp_train_loop(dp);
1590 		}
1591 	}
1592 
1593 handled:
1594 	return IRQ_HANDLED;
1595 }
1596 
1597 /* -----------------------------------------------------------------------------
1598  * Initialization & Cleanup
1599  */
1600 
1601 int zynqmp_dp_drm_init(struct zynqmp_dpsub *dpsub)
1602 {
1603 	struct zynqmp_dp *dp = dpsub->dp;
1604 	struct drm_encoder *encoder = &dp->encoder;
1605 	struct drm_connector *connector = &dp->connector;
1606 	int ret;
1607 
1608 	dp->config.misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK;
1609 	zynqmp_dp_set_format(dp, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1610 
1611 	/* Create the DRM encoder and connector. */
1612 	encoder->possible_crtcs |= zynqmp_disp_get_crtc_mask(dpsub->disp);
1613 	drm_simple_encoder_init(dp->drm, encoder, DRM_MODE_ENCODER_TMDS);
1614 	drm_encoder_helper_add(encoder, &zynqmp_dp_encoder_helper_funcs);
1615 
1616 	connector->polled = DRM_CONNECTOR_POLL_HPD;
1617 	ret = drm_connector_init(encoder->dev, connector,
1618 				 &zynqmp_dp_connector_funcs,
1619 				 DRM_MODE_CONNECTOR_DisplayPort);
1620 	if (ret) {
1621 		dev_err(dp->dev, "failed to create the DRM connector\n");
1622 		return ret;
1623 	}
1624 
1625 	drm_connector_helper_add(connector, &zynqmp_dp_connector_helper_funcs);
1626 	drm_connector_register(connector);
1627 	drm_connector_attach_encoder(connector, encoder);
1628 
1629 	/* Initialize and register the AUX adapter. */
1630 	ret = zynqmp_dp_aux_init(dp);
1631 	if (ret) {
1632 		dev_err(dp->dev, "failed to initialize DP aux\n");
1633 		return ret;
1634 	}
1635 
1636 	/* Now that initialisation is complete, enable interrupts. */
1637 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_ALL);
1638 
1639 	return 0;
1640 }
1641 
1642 int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm)
1643 {
1644 	struct platform_device *pdev = to_platform_device(dpsub->dev);
1645 	struct zynqmp_dp *dp;
1646 	struct resource *res;
1647 	int ret;
1648 
1649 	dp = drmm_kzalloc(drm, sizeof(*dp), GFP_KERNEL);
1650 	if (!dp)
1651 		return -ENOMEM;
1652 
1653 	dp->dev = &pdev->dev;
1654 	dp->dpsub = dpsub;
1655 	dp->status = connector_status_disconnected;
1656 	dp->drm = drm;
1657 
1658 	INIT_DELAYED_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func);
1659 
1660 	dpsub->dp = dp;
1661 
1662 	/* Acquire all resources (IOMEM, IRQ and PHYs). */
1663 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp");
1664 	dp->iomem = devm_ioremap_resource(dp->dev, res);
1665 	if (IS_ERR(dp->iomem))
1666 		return PTR_ERR(dp->iomem);
1667 
1668 	dp->irq = platform_get_irq(pdev, 0);
1669 	if (dp->irq < 0)
1670 		return dp->irq;
1671 
1672 	dp->reset = devm_reset_control_get(dp->dev, NULL);
1673 	if (IS_ERR(dp->reset)) {
1674 		if (PTR_ERR(dp->reset) != -EPROBE_DEFER)
1675 			dev_err(dp->dev, "failed to get reset: %ld\n",
1676 				PTR_ERR(dp->reset));
1677 		return PTR_ERR(dp->reset);
1678 	}
1679 
1680 	ret = zynqmp_dp_reset(dp, false);
1681 	if (ret < 0)
1682 		return ret;
1683 
1684 	ret = zynqmp_dp_phy_probe(dp);
1685 	if (ret)
1686 		goto err_reset;
1687 
1688 	/* Initialize the hardware. */
1689 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1690 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1691 	zynqmp_dp_set(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
1692 	zynqmp_dp_write(dp, ZYNQMP_DP_FORCE_SCRAMBLER_RESET, 1);
1693 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1694 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1695 
1696 	ret = zynqmp_dp_phy_init(dp);
1697 	if (ret)
1698 		goto err_reset;
1699 
1700 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1);
1701 
1702 	/*
1703 	 * Now that the hardware is initialized and won't generate spurious
1704 	 * interrupts, request the IRQ.
1705 	 */
1706 	ret = devm_request_threaded_irq(dp->dev, dp->irq, NULL,
1707 					zynqmp_dp_irq_handler, IRQF_ONESHOT,
1708 					dev_name(dp->dev), dp);
1709 	if (ret < 0)
1710 		goto err_phy_exit;
1711 
1712 	dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n",
1713 		dp->num_lanes);
1714 
1715 	return 0;
1716 
1717 err_phy_exit:
1718 	zynqmp_dp_phy_exit(dp);
1719 err_reset:
1720 	zynqmp_dp_reset(dp, true);
1721 
1722 	return ret;
1723 }
1724 
1725 void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub)
1726 {
1727 	struct zynqmp_dp *dp = dpsub->dp;
1728 
1729 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL);
1730 	disable_irq(dp->irq);
1731 
1732 	cancel_delayed_work_sync(&dp->hpd_work);
1733 	zynqmp_dp_aux_cleanup(dp);
1734 
1735 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1736 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1737 
1738 	zynqmp_dp_phy_exit(dp);
1739 	zynqmp_dp_reset(dp, true);
1740 }
1741