xref: /openbmc/linux/drivers/gpu/drm/xlnx/zynqmp_dp.c (revision ca637c0e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ZynqMP DisplayPort Driver
4  *
5  * Copyright (C) 2017 - 2020 Xilinx, Inc.
6  *
7  * Authors:
8  * - Hyun Woo Kwon <hyun.kwon@xilinx.com>
9  * - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
10  */
11 
12 #include <drm/display/drm_dp_helper.h>
13 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_connector.h>
15 #include <drm/drm_crtc.h>
16 #include <drm/drm_device.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/io.h>
29 #include <linux/module.h>
30 #include <linux/platform_device.h>
31 #include <linux/pm_runtime.h>
32 #include <linux/phy/phy.h>
33 #include <linux/reset.h>
34 
35 #include "zynqmp_disp.h"
36 #include "zynqmp_dp.h"
37 #include "zynqmp_dpsub.h"
38 
39 static uint zynqmp_dp_aux_timeout_ms = 50;
40 module_param_named(aux_timeout_ms, zynqmp_dp_aux_timeout_ms, uint, 0444);
41 MODULE_PARM_DESC(aux_timeout_ms, "DP aux timeout value in msec (default: 50)");
42 
43 /*
44  * Some sink requires a delay after power on request
45  */
46 static uint zynqmp_dp_power_on_delay_ms = 4;
47 module_param_named(power_on_delay_ms, zynqmp_dp_power_on_delay_ms, uint, 0444);
48 MODULE_PARM_DESC(power_on_delay_ms, "DP power on delay in msec (default: 4)");
49 
50 /* Link configuration registers */
51 #define ZYNQMP_DP_LINK_BW_SET				0x0
52 #define ZYNQMP_DP_LANE_COUNT_SET			0x4
53 #define ZYNQMP_DP_ENHANCED_FRAME_EN			0x8
54 #define ZYNQMP_DP_TRAINING_PATTERN_SET			0xc
55 #define ZYNQMP_DP_SCRAMBLING_DISABLE			0x14
56 #define ZYNQMP_DP_DOWNSPREAD_CTL			0x18
57 #define ZYNQMP_DP_SOFTWARE_RESET			0x1c
58 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM1		BIT(0)
59 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM2		BIT(1)
60 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM3		BIT(2)
61 #define ZYNQMP_DP_SOFTWARE_RESET_STREAM4		BIT(3)
62 #define ZYNQMP_DP_SOFTWARE_RESET_AUX			BIT(7)
63 #define ZYNQMP_DP_SOFTWARE_RESET_ALL			(ZYNQMP_DP_SOFTWARE_RESET_STREAM1 | \
64 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM2 | \
65 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM3 | \
66 							 ZYNQMP_DP_SOFTWARE_RESET_STREAM4 | \
67 							 ZYNQMP_DP_SOFTWARE_RESET_AUX)
68 
69 /* Core enable registers */
70 #define ZYNQMP_DP_TRANSMITTER_ENABLE			0x80
71 #define ZYNQMP_DP_MAIN_STREAM_ENABLE			0x84
72 #define ZYNQMP_DP_FORCE_SCRAMBLER_RESET			0xc0
73 #define ZYNQMP_DP_VERSION				0xf8
74 #define ZYNQMP_DP_VERSION_MAJOR_MASK			GENMASK(31, 24)
75 #define ZYNQMP_DP_VERSION_MAJOR_SHIFT			24
76 #define ZYNQMP_DP_VERSION_MINOR_MASK			GENMASK(23, 16)
77 #define ZYNQMP_DP_VERSION_MINOR_SHIFT			16
78 #define ZYNQMP_DP_VERSION_REVISION_MASK			GENMASK(15, 12)
79 #define ZYNQMP_DP_VERSION_REVISION_SHIFT		12
80 #define ZYNQMP_DP_VERSION_PATCH_MASK			GENMASK(11, 8)
81 #define ZYNQMP_DP_VERSION_PATCH_SHIFT			8
82 #define ZYNQMP_DP_VERSION_INTERNAL_MASK			GENMASK(7, 0)
83 #define ZYNQMP_DP_VERSION_INTERNAL_SHIFT		0
84 
85 /* Core ID registers */
86 #define ZYNQMP_DP_CORE_ID				0xfc
87 #define ZYNQMP_DP_CORE_ID_MAJOR_MASK			GENMASK(31, 24)
88 #define ZYNQMP_DP_CORE_ID_MAJOR_SHIFT			24
89 #define ZYNQMP_DP_CORE_ID_MINOR_MASK			GENMASK(23, 16)
90 #define ZYNQMP_DP_CORE_ID_MINOR_SHIFT			16
91 #define ZYNQMP_DP_CORE_ID_REVISION_MASK			GENMASK(15, 8)
92 #define ZYNQMP_DP_CORE_ID_REVISION_SHIFT		8
93 #define ZYNQMP_DP_CORE_ID_DIRECTION			GENMASK(1)
94 
95 /* AUX channel interface registers */
96 #define ZYNQMP_DP_AUX_COMMAND				0x100
97 #define ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT			8
98 #define ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY		BIT(12)
99 #define ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT		0
100 #define ZYNQMP_DP_AUX_WRITE_FIFO			0x104
101 #define ZYNQMP_DP_AUX_ADDRESS				0x108
102 #define ZYNQMP_DP_AUX_CLK_DIVIDER			0x10c
103 #define ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT	8
104 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE		0x130
105 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD		BIT(0)
106 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST	BIT(1)
107 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY		BIT(2)
108 #define ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT	BIT(3)
109 #define ZYNQMP_DP_AUX_REPLY_DATA			0x134
110 #define ZYNQMP_DP_AUX_REPLY_CODE			0x138
111 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK		(0)
112 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_NACK		BIT(0)
113 #define ZYNQMP_DP_AUX_REPLY_CODE_AUX_DEFER		BIT(1)
114 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK		(0)
115 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_NACK		BIT(2)
116 #define ZYNQMP_DP_AUX_REPLY_CODE_I2C_DEFER		BIT(3)
117 #define ZYNQMP_DP_AUX_REPLY_COUNT			0x13c
118 #define ZYNQMP_DP_REPLY_DATA_COUNT			0x148
119 #define ZYNQMP_DP_REPLY_DATA_COUNT_MASK			0xff
120 #define ZYNQMP_DP_INT_STATUS				0x3a0
121 #define ZYNQMP_DP_INT_MASK				0x3a4
122 #define ZYNQMP_DP_INT_EN				0x3a8
123 #define ZYNQMP_DP_INT_DS				0x3ac
124 #define ZYNQMP_DP_INT_HPD_IRQ				BIT(0)
125 #define ZYNQMP_DP_INT_HPD_EVENT				BIT(1)
126 #define ZYNQMP_DP_INT_REPLY_RECEIVED			BIT(2)
127 #define ZYNQMP_DP_INT_REPLY_TIMEOUT			BIT(3)
128 #define ZYNQMP_DP_INT_HPD_PULSE_DET			BIT(4)
129 #define ZYNQMP_DP_INT_EXT_PKT_TXD			BIT(5)
130 #define ZYNQMP_DP_INT_LIV_ABUF_UNDRFLW			BIT(12)
131 #define ZYNQMP_DP_INT_VBLANK_START			BIT(13)
132 #define ZYNQMP_DP_INT_PIXEL1_MATCH			BIT(14)
133 #define ZYNQMP_DP_INT_PIXEL0_MATCH			BIT(15)
134 #define ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK		0x3f0000
135 #define ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK		0xfc00000
136 #define ZYNQMP_DP_INT_CUST_TS_2				BIT(28)
137 #define ZYNQMP_DP_INT_CUST_TS				BIT(29)
138 #define ZYNQMP_DP_INT_EXT_VSYNC_TS			BIT(30)
139 #define ZYNQMP_DP_INT_VSYNC_TS				BIT(31)
140 #define ZYNQMP_DP_INT_ALL				(ZYNQMP_DP_INT_HPD_IRQ | \
141 							 ZYNQMP_DP_INT_HPD_EVENT | \
142 							 ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK | \
143 							 ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
144 
145 /* Main stream attribute registers */
146 #define ZYNQMP_DP_MAIN_STREAM_HTOTAL			0x180
147 #define ZYNQMP_DP_MAIN_STREAM_VTOTAL			0x184
148 #define ZYNQMP_DP_MAIN_STREAM_POLARITY			0x188
149 #define ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT	0
150 #define ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT	1
151 #define ZYNQMP_DP_MAIN_STREAM_HSWIDTH			0x18c
152 #define ZYNQMP_DP_MAIN_STREAM_VSWIDTH			0x190
153 #define ZYNQMP_DP_MAIN_STREAM_HRES			0x194
154 #define ZYNQMP_DP_MAIN_STREAM_VRES			0x198
155 #define ZYNQMP_DP_MAIN_STREAM_HSTART			0x19c
156 #define ZYNQMP_DP_MAIN_STREAM_VSTART			0x1a0
157 #define ZYNQMP_DP_MAIN_STREAM_MISC0			0x1a4
158 #define ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK		BIT(0)
159 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB	(0 << 1)
160 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422	(5 << 1)
161 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444	(6 << 1)
162 #define ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK	(7 << 1)
163 #define ZYNQMP_DP_MAIN_STREAM_MISC0_DYNAMIC_RANGE	BIT(3)
164 #define ZYNQMP_DP_MAIN_STREAM_MISC0_YCBCR_COLR		BIT(4)
165 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6		(0 << 5)
166 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8		(1 << 5)
167 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10		(2 << 5)
168 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12		(3 << 5)
169 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16		(4 << 5)
170 #define ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK		(7 << 5)
171 #define ZYNQMP_DP_MAIN_STREAM_MISC1			0x1a8
172 #define ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN		BIT(7)
173 #define ZYNQMP_DP_MAIN_STREAM_M_VID			0x1ac
174 #define ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE		0x1b0
175 #define ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF	64
176 #define ZYNQMP_DP_MAIN_STREAM_N_VID			0x1b4
177 #define ZYNQMP_DP_USER_PIX_WIDTH			0x1b8
178 #define ZYNQMP_DP_USER_DATA_COUNT_PER_LANE		0x1bc
179 #define ZYNQMP_DP_MIN_BYTES_PER_TU			0x1c4
180 #define ZYNQMP_DP_FRAC_BYTES_PER_TU			0x1c8
181 #define ZYNQMP_DP_INIT_WAIT				0x1cc
182 
183 /* PHY configuration and status registers */
184 #define ZYNQMP_DP_PHY_RESET				0x200
185 #define ZYNQMP_DP_PHY_RESET_PHY_RESET			BIT(0)
186 #define ZYNQMP_DP_PHY_RESET_GTTX_RESET			BIT(1)
187 #define ZYNQMP_DP_PHY_RESET_PHY_PMA_RESET		BIT(8)
188 #define ZYNQMP_DP_PHY_RESET_PHY_PCS_RESET		BIT(9)
189 #define ZYNQMP_DP_PHY_RESET_ALL_RESET			(ZYNQMP_DP_PHY_RESET_PHY_RESET | \
190 							 ZYNQMP_DP_PHY_RESET_GTTX_RESET | \
191 							 ZYNQMP_DP_PHY_RESET_PHY_PMA_RESET | \
192 							 ZYNQMP_DP_PHY_RESET_PHY_PCS_RESET)
193 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_0		0x210
194 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_1		0x214
195 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_2		0x218
196 #define ZYNQMP_DP_PHY_PREEMPHASIS_LANE_3		0x21c
197 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_0		0x220
198 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_1		0x224
199 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_2		0x228
200 #define ZYNQMP_DP_PHY_VOLTAGE_DIFF_LANE_3		0x22c
201 #define ZYNQMP_DP_PHY_CLOCK_SELECT			0x234
202 #define ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G		0x1
203 #define ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G		0x3
204 #define ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G		0x5
205 #define ZYNQMP_DP_TX_PHY_POWER_DOWN			0x238
206 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_0		BIT(0)
207 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_1		BIT(1)
208 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_2		BIT(2)
209 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_LANE_3		BIT(3)
210 #define ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL			0xf
211 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_0			0x23c
212 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_1			0x240
213 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_2			0x244
214 #define ZYNQMP_DP_PHY_PRECURSOR_LANE_3			0x248
215 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_0			0x24c
216 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_1			0x250
217 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_2			0x254
218 #define ZYNQMP_DP_PHY_POSTCURSOR_LANE_3			0x258
219 #define ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0		0x24c
220 #define ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_1		0x250
221 #define ZYNQMP_DP_PHY_STATUS				0x280
222 #define ZYNQMP_DP_PHY_STATUS_PLL_LOCKED_SHIFT		4
223 #define ZYNQMP_DP_PHY_STATUS_FPGA_PLL_LOCKED		BIT(6)
224 
225 /* Audio registers */
226 #define ZYNQMP_DP_TX_AUDIO_CONTROL			0x300
227 #define ZYNQMP_DP_TX_AUDIO_CHANNELS			0x304
228 #define ZYNQMP_DP_TX_AUDIO_INFO_DATA			0x308
229 #define ZYNQMP_DP_TX_M_AUD				0x328
230 #define ZYNQMP_DP_TX_N_AUD				0x32c
231 #define ZYNQMP_DP_TX_AUDIO_EXT_DATA			0x330
232 
233 #define ZYNQMP_DP_MAX_LANES				2
234 #define ZYNQMP_MAX_FREQ					3000000
235 
236 #define DP_REDUCED_BIT_RATE				162000
237 #define DP_HIGH_BIT_RATE				270000
238 #define DP_HIGH_BIT_RATE2				540000
239 #define DP_MAX_TRAINING_TRIES				5
240 #define DP_V1_2						0x12
241 
242 /**
243  * struct zynqmp_dp_link_config - Common link config between source and sink
244  * @max_rate: maximum link rate
245  * @max_lanes: maximum number of lanes
246  */
247 struct zynqmp_dp_link_config {
248 	int max_rate;
249 	u8 max_lanes;
250 };
251 
252 /**
253  * struct zynqmp_dp_mode - Configured mode of DisplayPort
254  * @bw_code: code for bandwidth(link rate)
255  * @lane_cnt: number of lanes
256  * @pclock: pixel clock frequency of current mode
257  * @fmt: format identifier string
258  */
259 struct zynqmp_dp_mode {
260 	u8 bw_code;
261 	u8 lane_cnt;
262 	int pclock;
263 	const char *fmt;
264 };
265 
266 /**
267  * struct zynqmp_dp_config - Configuration of DisplayPort from DTS
268  * @misc0: misc0 configuration (per DP v1.2 spec)
269  * @misc1: misc1 configuration (per DP v1.2 spec)
270  * @bpp: bits per pixel
271  */
272 struct zynqmp_dp_config {
273 	u8 misc0;
274 	u8 misc1;
275 	u8 bpp;
276 };
277 
278 /**
279  * struct zynqmp_dp - Xilinx DisplayPort core
280  * @encoder: the drm encoder structure
281  * @connector: the drm connector structure
282  * @dev: device structure
283  * @dpsub: Display subsystem
284  * @drm: DRM core
285  * @iomem: device I/O memory for register access
286  * @reset: reset controller
287  * @irq: irq
288  * @config: IP core configuration from DTS
289  * @aux: aux channel
290  * @phy: PHY handles for DP lanes
291  * @num_lanes: number of enabled phy lanes
292  * @hpd_work: hot plug detection worker
293  * @status: connection status
294  * @enabled: flag to indicate if the device is enabled
295  * @dpcd: DP configuration data from currently connected sink device
296  * @link_config: common link configuration between IP core and sink device
297  * @mode: current mode between IP core and sink device
298  * @train_set: set of training data
299  */
300 struct zynqmp_dp {
301 	struct drm_encoder encoder;
302 	struct drm_connector connector;
303 	struct device *dev;
304 	struct zynqmp_dpsub *dpsub;
305 	struct drm_device *drm;
306 	void __iomem *iomem;
307 	struct reset_control *reset;
308 	int irq;
309 
310 	struct zynqmp_dp_config config;
311 	struct drm_dp_aux aux;
312 	struct phy *phy[ZYNQMP_DP_MAX_LANES];
313 	u8 num_lanes;
314 	struct delayed_work hpd_work;
315 	enum drm_connector_status status;
316 	bool enabled;
317 
318 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
319 	struct zynqmp_dp_link_config link_config;
320 	struct zynqmp_dp_mode mode;
321 	u8 train_set[ZYNQMP_DP_MAX_LANES];
322 };
323 
324 static inline struct zynqmp_dp *encoder_to_dp(struct drm_encoder *encoder)
325 {
326 	return container_of(encoder, struct zynqmp_dp, encoder);
327 }
328 
329 static inline struct zynqmp_dp *connector_to_dp(struct drm_connector *connector)
330 {
331 	return container_of(connector, struct zynqmp_dp, connector);
332 }
333 
334 static void zynqmp_dp_write(struct zynqmp_dp *dp, int offset, u32 val)
335 {
336 	writel(val, dp->iomem + offset);
337 }
338 
339 static u32 zynqmp_dp_read(struct zynqmp_dp *dp, int offset)
340 {
341 	return readl(dp->iomem + offset);
342 }
343 
344 static void zynqmp_dp_clr(struct zynqmp_dp *dp, int offset, u32 clr)
345 {
346 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) & ~clr);
347 }
348 
349 static void zynqmp_dp_set(struct zynqmp_dp *dp, int offset, u32 set)
350 {
351 	zynqmp_dp_write(dp, offset, zynqmp_dp_read(dp, offset) | set);
352 }
353 
354 /* -----------------------------------------------------------------------------
355  * PHY Handling
356  */
357 
358 #define RST_TIMEOUT_MS			1000
359 
360 static int zynqmp_dp_reset(struct zynqmp_dp *dp, bool assert)
361 {
362 	unsigned long timeout;
363 
364 	if (assert)
365 		reset_control_assert(dp->reset);
366 	else
367 		reset_control_deassert(dp->reset);
368 
369 	/* Wait for the (de)assert to complete. */
370 	timeout = jiffies + msecs_to_jiffies(RST_TIMEOUT_MS);
371 	while (!time_after_eq(jiffies, timeout)) {
372 		bool status = !!reset_control_status(dp->reset);
373 
374 		if (assert == status)
375 			return 0;
376 
377 		cpu_relax();
378 	}
379 
380 	dev_err(dp->dev, "reset %s timeout\n", assert ? "assert" : "deassert");
381 	return -ETIMEDOUT;
382 }
383 
384 /**
385  * zynqmp_dp_phy_init - Initialize the phy
386  * @dp: DisplayPort IP core structure
387  *
388  * Initialize the phy.
389  *
390  * Return: 0 if the phy instances are initialized correctly, or the error code
391  * returned from the callee functions.
392  */
393 static int zynqmp_dp_phy_init(struct zynqmp_dp *dp)
394 {
395 	int ret;
396 	int i;
397 
398 	for (i = 0; i < dp->num_lanes; i++) {
399 		ret = phy_init(dp->phy[i]);
400 		if (ret) {
401 			dev_err(dp->dev, "failed to init phy lane %d\n", i);
402 			return ret;
403 		}
404 	}
405 
406 	zynqmp_dp_clr(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
407 
408 	/*
409 	 * Power on lanes in reverse order as only lane 0 waits for the PLL to
410 	 * lock.
411 	 */
412 	for (i = dp->num_lanes - 1; i >= 0; i--) {
413 		ret = phy_power_on(dp->phy[i]);
414 		if (ret) {
415 			dev_err(dp->dev, "failed to power on phy lane %d\n", i);
416 			return ret;
417 		}
418 	}
419 
420 	return 0;
421 }
422 
423 /**
424  * zynqmp_dp_phy_exit - Exit the phy
425  * @dp: DisplayPort IP core structure
426  *
427  * Exit the phy.
428  */
429 static void zynqmp_dp_phy_exit(struct zynqmp_dp *dp)
430 {
431 	unsigned int i;
432 	int ret;
433 
434 	for (i = 0; i < dp->num_lanes; i++) {
435 		ret = phy_power_off(dp->phy[i]);
436 		if (ret)
437 			dev_err(dp->dev, "failed to power off phy(%d) %d\n", i,
438 				ret);
439 	}
440 
441 	for (i = 0; i < dp->num_lanes; i++) {
442 		ret = phy_exit(dp->phy[i]);
443 		if (ret)
444 			dev_err(dp->dev, "failed to exit phy(%d) %d\n", i, ret);
445 	}
446 }
447 
448 /**
449  * zynqmp_dp_phy_probe - Probe the PHYs
450  * @dp: DisplayPort IP core structure
451  *
452  * Probe PHYs for all lanes. Less PHYs may be available than the number of
453  * lanes, which is not considered an error as long as at least one PHY is
454  * found. The caller can check dp->num_lanes to check how many PHYs were found.
455  *
456  * Return:
457  * * 0				- Success
458  * * -ENXIO			- No PHY found
459  * * -EPROBE_DEFER		- Probe deferral requested
460  * * Other negative value	- PHY retrieval failure
461  */
462 static int zynqmp_dp_phy_probe(struct zynqmp_dp *dp)
463 {
464 	unsigned int i;
465 
466 	for (i = 0; i < ZYNQMP_DP_MAX_LANES; i++) {
467 		char phy_name[16];
468 		struct phy *phy;
469 
470 		snprintf(phy_name, sizeof(phy_name), "dp-phy%d", i);
471 		phy = devm_phy_get(dp->dev, phy_name);
472 
473 		if (IS_ERR(phy)) {
474 			switch (PTR_ERR(phy)) {
475 			case -ENODEV:
476 				if (dp->num_lanes)
477 					return 0;
478 
479 				dev_err(dp->dev, "no PHY found\n");
480 				return -ENXIO;
481 
482 			case -EPROBE_DEFER:
483 				return -EPROBE_DEFER;
484 
485 			default:
486 				dev_err(dp->dev, "failed to get PHY lane %u\n",
487 					i);
488 				return PTR_ERR(phy);
489 			}
490 		}
491 
492 		dp->phy[i] = phy;
493 		dp->num_lanes++;
494 	}
495 
496 	return 0;
497 }
498 
499 /**
500  * zynqmp_dp_phy_ready - Check if PHY is ready
501  * @dp: DisplayPort IP core structure
502  *
503  * Check if PHY is ready. If PHY is not ready, wait 1ms to check for 100 times.
504  * This amount of delay was suggested by IP designer.
505  *
506  * Return: 0 if PHY is ready, or -ENODEV if PHY is not ready.
507  */
508 static int zynqmp_dp_phy_ready(struct zynqmp_dp *dp)
509 {
510 	u32 i, reg, ready;
511 
512 	ready = (1 << dp->num_lanes) - 1;
513 
514 	/* Wait for 100 * 1ms. This should be enough time for PHY to be ready */
515 	for (i = 0; ; i++) {
516 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_PHY_STATUS);
517 		if ((reg & ready) == ready)
518 			return 0;
519 
520 		if (i == 100) {
521 			dev_err(dp->dev, "PHY isn't ready\n");
522 			return -ENODEV;
523 		}
524 
525 		usleep_range(1000, 1100);
526 	}
527 
528 	return 0;
529 }
530 
531 /* -----------------------------------------------------------------------------
532  * DisplayPort Link Training
533  */
534 
535 /**
536  * zynqmp_dp_max_rate - Calculate and return available max pixel clock
537  * @link_rate: link rate (Kilo-bytes / sec)
538  * @lane_num: number of lanes
539  * @bpp: bits per pixel
540  *
541  * Return: max pixel clock (KHz) supported by current link config.
542  */
543 static inline int zynqmp_dp_max_rate(int link_rate, u8 lane_num, u8 bpp)
544 {
545 	return link_rate * lane_num * 8 / bpp;
546 }
547 
548 /**
549  * zynqmp_dp_mode_configure - Configure the link values
550  * @dp: DisplayPort IP core structure
551  * @pclock: pixel clock for requested display mode
552  * @current_bw: current link rate
553  *
554  * Find the link configuration values, rate and lane count for requested pixel
555  * clock @pclock. The @pclock is stored in the mode to be used in other
556  * functions later. The returned rate is downshifted from the current rate
557  * @current_bw.
558  *
559  * Return: Current link rate code, or -EINVAL.
560  */
561 static int zynqmp_dp_mode_configure(struct zynqmp_dp *dp, int pclock,
562 				    u8 current_bw)
563 {
564 	int max_rate = dp->link_config.max_rate;
565 	u8 bw_code;
566 	u8 max_lanes = dp->link_config.max_lanes;
567 	u8 max_link_rate_code = drm_dp_link_rate_to_bw_code(max_rate);
568 	u8 bpp = dp->config.bpp;
569 	u8 lane_cnt;
570 
571 	/* Downshift from current bandwidth */
572 	switch (current_bw) {
573 	case DP_LINK_BW_5_4:
574 		bw_code = DP_LINK_BW_2_7;
575 		break;
576 	case DP_LINK_BW_2_7:
577 		bw_code = DP_LINK_BW_1_62;
578 		break;
579 	case DP_LINK_BW_1_62:
580 		dev_err(dp->dev, "can't downshift. already lowest link rate\n");
581 		return -EINVAL;
582 	default:
583 		/* If not given, start with max supported */
584 		bw_code = max_link_rate_code;
585 		break;
586 	}
587 
588 	for (lane_cnt = 1; lane_cnt <= max_lanes; lane_cnt <<= 1) {
589 		int bw;
590 		u32 rate;
591 
592 		bw = drm_dp_bw_code_to_link_rate(bw_code);
593 		rate = zynqmp_dp_max_rate(bw, lane_cnt, bpp);
594 		if (pclock <= rate) {
595 			dp->mode.bw_code = bw_code;
596 			dp->mode.lane_cnt = lane_cnt;
597 			dp->mode.pclock = pclock;
598 			return dp->mode.bw_code;
599 		}
600 	}
601 
602 	dev_err(dp->dev, "failed to configure link values\n");
603 
604 	return -EINVAL;
605 }
606 
607 /**
608  * zynqmp_dp_adjust_train - Adjust train values
609  * @dp: DisplayPort IP core structure
610  * @link_status: link status from sink which contains requested training values
611  */
612 static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp,
613 				   u8 link_status[DP_LINK_STATUS_SIZE])
614 {
615 	u8 *train_set = dp->train_set;
616 	u8 voltage = 0, preemphasis = 0;
617 	u8 i;
618 
619 	for (i = 0; i < dp->mode.lane_cnt; i++) {
620 		u8 v = drm_dp_get_adjust_request_voltage(link_status, i);
621 		u8 p = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
622 
623 		if (v > voltage)
624 			voltage = v;
625 
626 		if (p > preemphasis)
627 			preemphasis = p;
628 	}
629 
630 	if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3)
631 		voltage |= DP_TRAIN_MAX_SWING_REACHED;
632 
633 	if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2)
634 		preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
635 
636 	for (i = 0; i < dp->mode.lane_cnt; i++)
637 		train_set[i] = voltage | preemphasis;
638 }
639 
640 /**
641  * zynqmp_dp_update_vs_emph - Update the training values
642  * @dp: DisplayPort IP core structure
643  *
644  * Update the training values based on the request from sink. The mapped values
645  * are predefined, and values(vs, pe, pc) are from the device manual.
646  *
647  * Return: 0 if vs and emph are updated successfully, or the error code returned
648  * by drm_dp_dpcd_write().
649  */
650 static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
651 {
652 	unsigned int i;
653 	int ret;
654 
655 	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->train_set,
656 				dp->mode.lane_cnt);
657 	if (ret < 0)
658 		return ret;
659 
660 	for (i = 0; i < dp->mode.lane_cnt; i++) {
661 		u32 reg = ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0 + i * 4;
662 		union phy_configure_opts opts = { 0 };
663 		u8 train = dp->train_set[i];
664 
665 		opts.dp.voltage[0] = (train & DP_TRAIN_VOLTAGE_SWING_MASK)
666 				   >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
667 		opts.dp.pre[0] = (train & DP_TRAIN_PRE_EMPHASIS_MASK)
668 			       >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
669 
670 		phy_configure(dp->phy[i], &opts);
671 
672 		zynqmp_dp_write(dp, reg, 0x2);
673 	}
674 
675 	return 0;
676 }
677 
678 /**
679  * zynqmp_dp_link_train_cr - Train clock recovery
680  * @dp: DisplayPort IP core structure
681  *
682  * Return: 0 if clock recovery train is done successfully, or corresponding
683  * error code.
684  */
685 static int zynqmp_dp_link_train_cr(struct zynqmp_dp *dp)
686 {
687 	u8 link_status[DP_LINK_STATUS_SIZE];
688 	u8 lane_cnt = dp->mode.lane_cnt;
689 	u8 vs = 0, tries = 0;
690 	u16 max_tries, i;
691 	bool cr_done;
692 	int ret;
693 
694 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
695 			DP_TRAINING_PATTERN_1);
696 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
697 				 DP_TRAINING_PATTERN_1 |
698 				 DP_LINK_SCRAMBLING_DISABLE);
699 	if (ret < 0)
700 		return ret;
701 
702 	/*
703 	 * 256 loops should be maximum iterations for 4 lanes and 4 values.
704 	 * So, This loop should exit before 512 iterations
705 	 */
706 	for (max_tries = 0; max_tries < 512; max_tries++) {
707 		ret = zynqmp_dp_update_vs_emph(dp);
708 		if (ret)
709 			return ret;
710 
711 		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
712 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
713 		if (ret < 0)
714 			return ret;
715 
716 		cr_done = drm_dp_clock_recovery_ok(link_status, lane_cnt);
717 		if (cr_done)
718 			break;
719 
720 		for (i = 0; i < lane_cnt; i++)
721 			if (!(dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED))
722 				break;
723 		if (i == lane_cnt)
724 			break;
725 
726 		if ((dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == vs)
727 			tries++;
728 		else
729 			tries = 0;
730 
731 		if (tries == DP_MAX_TRAINING_TRIES)
732 			break;
733 
734 		vs = dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
735 		zynqmp_dp_adjust_train(dp, link_status);
736 	}
737 
738 	if (!cr_done)
739 		return -EIO;
740 
741 	return 0;
742 }
743 
744 /**
745  * zynqmp_dp_link_train_ce - Train channel equalization
746  * @dp: DisplayPort IP core structure
747  *
748  * Return: 0 if channel equalization train is done successfully, or
749  * corresponding error code.
750  */
751 static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
752 {
753 	u8 link_status[DP_LINK_STATUS_SIZE];
754 	u8 lane_cnt = dp->mode.lane_cnt;
755 	u32 pat, tries;
756 	int ret;
757 	bool ce_done;
758 
759 	if (dp->dpcd[DP_DPCD_REV] >= DP_V1_2 &&
760 	    dp->dpcd[DP_MAX_LANE_COUNT] & DP_TPS3_SUPPORTED)
761 		pat = DP_TRAINING_PATTERN_3;
762 	else
763 		pat = DP_TRAINING_PATTERN_2;
764 
765 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET, pat);
766 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
767 				 pat | DP_LINK_SCRAMBLING_DISABLE);
768 	if (ret < 0)
769 		return ret;
770 
771 	for (tries = 0; tries < DP_MAX_TRAINING_TRIES; tries++) {
772 		ret = zynqmp_dp_update_vs_emph(dp);
773 		if (ret)
774 			return ret;
775 
776 		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
777 		ret = drm_dp_dpcd_read_link_status(&dp->aux, link_status);
778 		if (ret < 0)
779 			return ret;
780 
781 		ce_done = drm_dp_channel_eq_ok(link_status, lane_cnt);
782 		if (ce_done)
783 			break;
784 
785 		zynqmp_dp_adjust_train(dp, link_status);
786 	}
787 
788 	if (!ce_done)
789 		return -EIO;
790 
791 	return 0;
792 }
793 
794 /**
795  * zynqmp_dp_link_train - Train the link
796  * @dp: DisplayPort IP core structure
797  *
798  * Return: 0 if all trains are done successfully, or corresponding error code.
799  */
800 static int zynqmp_dp_train(struct zynqmp_dp *dp)
801 {
802 	u32 reg;
803 	u8 bw_code = dp->mode.bw_code;
804 	u8 lane_cnt = dp->mode.lane_cnt;
805 	u8 aux_lane_cnt = lane_cnt;
806 	bool enhanced;
807 	int ret;
808 
809 	zynqmp_dp_write(dp, ZYNQMP_DP_LANE_COUNT_SET, lane_cnt);
810 	enhanced = drm_dp_enhanced_frame_cap(dp->dpcd);
811 	if (enhanced) {
812 		zynqmp_dp_write(dp, ZYNQMP_DP_ENHANCED_FRAME_EN, 1);
813 		aux_lane_cnt |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
814 	}
815 
816 	if (dp->dpcd[3] & 0x1) {
817 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 1);
818 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL,
819 				   DP_SPREAD_AMP_0_5);
820 	} else {
821 		zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 0);
822 		drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL, 0);
823 	}
824 
825 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET, aux_lane_cnt);
826 	if (ret < 0) {
827 		dev_err(dp->dev, "failed to set lane count\n");
828 		return ret;
829 	}
830 
831 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
832 				 DP_SET_ANSI_8B10B);
833 	if (ret < 0) {
834 		dev_err(dp->dev, "failed to set ANSI 8B/10B encoding\n");
835 		return ret;
836 	}
837 
838 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_LINK_BW_SET, bw_code);
839 	if (ret < 0) {
840 		dev_err(dp->dev, "failed to set DP bandwidth\n");
841 		return ret;
842 	}
843 
844 	zynqmp_dp_write(dp, ZYNQMP_DP_LINK_BW_SET, bw_code);
845 	switch (bw_code) {
846 	case DP_LINK_BW_1_62:
847 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_1_62G;
848 		break;
849 	case DP_LINK_BW_2_7:
850 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_2_70G;
851 		break;
852 	case DP_LINK_BW_5_4:
853 	default:
854 		reg = ZYNQMP_DP_PHY_CLOCK_SELECT_5_40G;
855 		break;
856 	}
857 
858 	zynqmp_dp_write(dp, ZYNQMP_DP_PHY_CLOCK_SELECT, reg);
859 	ret = zynqmp_dp_phy_ready(dp);
860 	if (ret < 0)
861 		return ret;
862 
863 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 1);
864 	memset(dp->train_set, 0, sizeof(dp->train_set));
865 	ret = zynqmp_dp_link_train_cr(dp);
866 	if (ret)
867 		return ret;
868 
869 	ret = zynqmp_dp_link_train_ce(dp);
870 	if (ret)
871 		return ret;
872 
873 	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
874 				 DP_TRAINING_PATTERN_DISABLE);
875 	if (ret < 0) {
876 		dev_err(dp->dev, "failed to disable training pattern\n");
877 		return ret;
878 	}
879 	zynqmp_dp_write(dp, ZYNQMP_DP_TRAINING_PATTERN_SET,
880 			DP_TRAINING_PATTERN_DISABLE);
881 
882 	zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 0);
883 
884 	return 0;
885 }
886 
887 /**
888  * zynqmp_dp_train_loop - Downshift the link rate during training
889  * @dp: DisplayPort IP core structure
890  *
891  * Train the link by downshifting the link rate if training is not successful.
892  */
893 static void zynqmp_dp_train_loop(struct zynqmp_dp *dp)
894 {
895 	struct zynqmp_dp_mode *mode = &dp->mode;
896 	u8 bw = mode->bw_code;
897 	int ret;
898 
899 	do {
900 		if (dp->status == connector_status_disconnected ||
901 		    !dp->enabled)
902 			return;
903 
904 		ret = zynqmp_dp_train(dp);
905 		if (!ret)
906 			return;
907 
908 		ret = zynqmp_dp_mode_configure(dp, mode->pclock, bw);
909 		if (ret < 0)
910 			goto err_out;
911 
912 		bw = ret;
913 	} while (bw >= DP_LINK_BW_1_62);
914 
915 err_out:
916 	dev_err(dp->dev, "failed to train the DP link\n");
917 }
918 
919 /* -----------------------------------------------------------------------------
920  * DisplayPort AUX
921  */
922 
923 #define AUX_READ_BIT	0x1
924 
925 /**
926  * zynqmp_dp_aux_cmd_submit - Submit aux command
927  * @dp: DisplayPort IP core structure
928  * @cmd: aux command
929  * @addr: aux address
930  * @buf: buffer for command data
931  * @bytes: number of bytes for @buf
932  * @reply: reply code to be returned
933  *
934  * Submit an aux command. All aux related commands, native or i2c aux
935  * read/write, are submitted through this function. The function is mapped to
936  * the transfer function of struct drm_dp_aux. This function involves in
937  * multiple register reads/writes, thus synchronization is needed, and it is
938  * done by drm_dp_helper using @hw_mutex. The calling thread goes into sleep
939  * if there's no immediate reply to the command submission. The reply code is
940  * returned at @reply if @reply != NULL.
941  *
942  * Return: 0 if the command is submitted properly, or corresponding error code:
943  * -EBUSY when there is any request already being processed
944  * -ETIMEDOUT when receiving reply is timed out
945  * -EIO when received bytes are less than requested
946  */
947 static int zynqmp_dp_aux_cmd_submit(struct zynqmp_dp *dp, u32 cmd, u16 addr,
948 				    u8 *buf, u8 bytes, u8 *reply)
949 {
950 	bool is_read = (cmd & AUX_READ_BIT) ? true : false;
951 	u32 reg, i;
952 
953 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
954 	if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REQUEST)
955 		return -EBUSY;
956 
957 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_ADDRESS, addr);
958 	if (!is_read)
959 		for (i = 0; i < bytes; i++)
960 			zynqmp_dp_write(dp, ZYNQMP_DP_AUX_WRITE_FIFO,
961 					buf[i]);
962 
963 	reg = cmd << ZYNQMP_DP_AUX_COMMAND_CMD_SHIFT;
964 	if (!buf || !bytes)
965 		reg |= ZYNQMP_DP_AUX_COMMAND_ADDRESS_ONLY;
966 	else
967 		reg |= (bytes - 1) << ZYNQMP_DP_AUX_COMMAND_BYTES_SHIFT;
968 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_COMMAND, reg);
969 
970 	/* Wait for reply to be delivered upto 2ms */
971 	for (i = 0; ; i++) {
972 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
973 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY)
974 			break;
975 
976 		if (reg & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_REPLY_TIMEOUT ||
977 		    i == 2)
978 			return -ETIMEDOUT;
979 
980 		usleep_range(1000, 1100);
981 	}
982 
983 	reg = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_CODE);
984 	if (reply)
985 		*reply = reg;
986 
987 	if (is_read &&
988 	    (reg == ZYNQMP_DP_AUX_REPLY_CODE_AUX_ACK ||
989 	     reg == ZYNQMP_DP_AUX_REPLY_CODE_I2C_ACK)) {
990 		reg = zynqmp_dp_read(dp, ZYNQMP_DP_REPLY_DATA_COUNT);
991 		if ((reg & ZYNQMP_DP_REPLY_DATA_COUNT_MASK) != bytes)
992 			return -EIO;
993 
994 		for (i = 0; i < bytes; i++)
995 			buf[i] = zynqmp_dp_read(dp, ZYNQMP_DP_AUX_REPLY_DATA);
996 	}
997 
998 	return 0;
999 }
1000 
1001 static ssize_t
1002 zynqmp_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
1003 {
1004 	struct zynqmp_dp *dp = container_of(aux, struct zynqmp_dp, aux);
1005 	int ret;
1006 	unsigned int i, iter;
1007 
1008 	/* Number of loops = timeout in msec / aux delay (400 usec) */
1009 	iter = zynqmp_dp_aux_timeout_ms * 1000 / 400;
1010 	iter = iter ? iter : 1;
1011 
1012 	for (i = 0; i < iter; i++) {
1013 		ret = zynqmp_dp_aux_cmd_submit(dp, msg->request, msg->address,
1014 					       msg->buffer, msg->size,
1015 					       &msg->reply);
1016 		if (!ret) {
1017 			dev_dbg(dp->dev, "aux %d retries\n", i);
1018 			return msg->size;
1019 		}
1020 
1021 		if (dp->status == connector_status_disconnected) {
1022 			dev_dbg(dp->dev, "no connected aux device\n");
1023 			return -ENODEV;
1024 		}
1025 
1026 		usleep_range(400, 500);
1027 	}
1028 
1029 	dev_dbg(dp->dev, "failed to do aux transfer (%d)\n", ret);
1030 
1031 	return ret;
1032 }
1033 
1034 /**
1035  * zynqmp_dp_aux_init - Initialize and register the DP AUX
1036  * @dp: DisplayPort IP core structure
1037  *
1038  * Program the AUX clock divider and filter and register the DP AUX adapter.
1039  *
1040  * Return: 0 on success, error value otherwise
1041  */
1042 static int zynqmp_dp_aux_init(struct zynqmp_dp *dp)
1043 {
1044 	unsigned long rate;
1045 	unsigned int w;
1046 
1047 	/*
1048 	 * The AUX_SIGNAL_WIDTH_FILTER is the number of APB clock cycles
1049 	 * corresponding to the AUX pulse. Allowable values are 8, 16, 24, 32,
1050 	 * 40 and 48. The AUX pulse width must be between 0.4µs and 0.6µs,
1051 	 * compute the w / 8 value corresponding to 0.4µs rounded up, and make
1052 	 * sure it stays below 0.6µs and within the allowable values.
1053 	 */
1054 	rate = clk_get_rate(dp->dpsub->apb_clk);
1055 	w = DIV_ROUND_UP(4 * rate, 1000 * 1000 * 10 * 8) * 8;
1056 	if (w > 6 * rate / (1000 * 1000 * 10) || w > 48) {
1057 		dev_err(dp->dev, "aclk frequency too high\n");
1058 		return -EINVAL;
1059 	}
1060 
1061 	zynqmp_dp_write(dp, ZYNQMP_DP_AUX_CLK_DIVIDER,
1062 			(w << ZYNQMP_DP_AUX_CLK_DIVIDER_AUX_FILTER_SHIFT) |
1063 			(rate / (1000 * 1000)));
1064 
1065 	dp->aux.name = "ZynqMP DP AUX";
1066 	dp->aux.dev = dp->dev;
1067 	dp->aux.drm_dev = dp->drm;
1068 	dp->aux.transfer = zynqmp_dp_aux_transfer;
1069 
1070 	return drm_dp_aux_register(&dp->aux);
1071 }
1072 
1073 /**
1074  * zynqmp_dp_aux_cleanup - Cleanup the DP AUX
1075  * @dp: DisplayPort IP core structure
1076  *
1077  * Unregister the DP AUX adapter.
1078  */
1079 static void zynqmp_dp_aux_cleanup(struct zynqmp_dp *dp)
1080 {
1081 	drm_dp_aux_unregister(&dp->aux);
1082 }
1083 
1084 /* -----------------------------------------------------------------------------
1085  * DisplayPort Generic Support
1086  */
1087 
1088 /**
1089  * zynqmp_dp_update_misc - Write the misc registers
1090  * @dp: DisplayPort IP core structure
1091  *
1092  * The misc register values are stored in the structure, and this
1093  * function applies the values into the registers.
1094  */
1095 static void zynqmp_dp_update_misc(struct zynqmp_dp *dp)
1096 {
1097 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC0, dp->config.misc0);
1098 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_MISC1, dp->config.misc1);
1099 }
1100 
1101 /**
1102  * zynqmp_dp_set_format - Set the input format
1103  * @dp: DisplayPort IP core structure
1104  * @format: input format
1105  * @bpc: bits per component
1106  *
1107  * Update misc register values based on input @format and @bpc.
1108  *
1109  * Return: 0 on success, or -EINVAL.
1110  */
1111 static int zynqmp_dp_set_format(struct zynqmp_dp *dp,
1112 				enum zynqmp_dpsub_format format,
1113 				unsigned int bpc)
1114 {
1115 	static const struct drm_display_info *display;
1116 	struct zynqmp_dp_config *config = &dp->config;
1117 	unsigned int num_colors;
1118 
1119 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_MASK;
1120 	config->misc1 &= ~ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1121 
1122 	switch (format) {
1123 	case ZYNQMP_DPSUB_FORMAT_RGB:
1124 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_RGB;
1125 		num_colors = 3;
1126 		break;
1127 
1128 	case ZYNQMP_DPSUB_FORMAT_YCRCB444:
1129 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_444;
1130 		num_colors = 3;
1131 		break;
1132 
1133 	case ZYNQMP_DPSUB_FORMAT_YCRCB422:
1134 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_COMP_FORMAT_YCRCB_422;
1135 		num_colors = 2;
1136 		break;
1137 
1138 	case ZYNQMP_DPSUB_FORMAT_YONLY:
1139 		config->misc1 |= ZYNQMP_DP_MAIN_STREAM_MISC1_Y_ONLY_EN;
1140 		num_colors = 1;
1141 		break;
1142 
1143 	default:
1144 		dev_err(dp->dev, "Invalid colormetry in DT\n");
1145 		return -EINVAL;
1146 	}
1147 
1148 	display = &dp->connector.display_info;
1149 	if (display->bpc && bpc > display->bpc) {
1150 		dev_warn(dp->dev,
1151 			 "downgrading requested %ubpc to display limit %ubpc\n",
1152 			 bpc, display->bpc);
1153 		bpc = display->bpc;
1154 	}
1155 
1156 	config->misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_MASK;
1157 
1158 	switch (bpc) {
1159 	case 6:
1160 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_6;
1161 		break;
1162 	case 8:
1163 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1164 		break;
1165 	case 10:
1166 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_10;
1167 		break;
1168 	case 12:
1169 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_12;
1170 		break;
1171 	case 16:
1172 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_16;
1173 		break;
1174 	default:
1175 		dev_warn(dp->dev, "Not supported bpc (%u). fall back to 8bpc\n",
1176 			 bpc);
1177 		config->misc0 |= ZYNQMP_DP_MAIN_STREAM_MISC0_BPC_8;
1178 		bpc = 8;
1179 		break;
1180 	}
1181 
1182 	/* Update the current bpp based on the format. */
1183 	config->bpp = bpc * num_colors;
1184 
1185 	return 0;
1186 }
1187 
1188 /**
1189  * zynqmp_dp_encoder_mode_set_transfer_unit - Set the transfer unit values
1190  * @dp: DisplayPort IP core structure
1191  * @mode: requested display mode
1192  *
1193  * Set the transfer unit, and calculate all transfer unit size related values.
1194  * Calculation is based on DP and IP core specification.
1195  */
1196 static void
1197 zynqmp_dp_encoder_mode_set_transfer_unit(struct zynqmp_dp *dp,
1198 					 struct drm_display_mode *mode)
1199 {
1200 	u32 tu = ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE_TU_SIZE_DEF;
1201 	u32 bw, vid_kbytes, avg_bytes_per_tu, init_wait;
1202 
1203 	/* Use the max transfer unit size (default) */
1204 	zynqmp_dp_write(dp, ZYNQMP_DP_MSA_TRANSFER_UNIT_SIZE, tu);
1205 
1206 	vid_kbytes = mode->clock * (dp->config.bpp / 8);
1207 	bw = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1208 	avg_bytes_per_tu = vid_kbytes * tu / (dp->mode.lane_cnt * bw / 1000);
1209 	zynqmp_dp_write(dp, ZYNQMP_DP_MIN_BYTES_PER_TU,
1210 			avg_bytes_per_tu / 1000);
1211 	zynqmp_dp_write(dp, ZYNQMP_DP_FRAC_BYTES_PER_TU,
1212 			avg_bytes_per_tu % 1000);
1213 
1214 	/* Configure the initial wait cycle based on transfer unit size */
1215 	if (tu < (avg_bytes_per_tu / 1000))
1216 		init_wait = 0;
1217 	else if ((avg_bytes_per_tu / 1000) <= 4)
1218 		init_wait = tu;
1219 	else
1220 		init_wait = tu - avg_bytes_per_tu / 1000;
1221 
1222 	zynqmp_dp_write(dp, ZYNQMP_DP_INIT_WAIT, init_wait);
1223 }
1224 
1225 /**
1226  * zynqmp_dp_encoder_mode_set_stream - Configure the main stream
1227  * @dp: DisplayPort IP core structure
1228  * @mode: requested display mode
1229  *
1230  * Configure the main stream based on the requested mode @mode. Calculation is
1231  * based on IP core specification.
1232  */
1233 static void zynqmp_dp_encoder_mode_set_stream(struct zynqmp_dp *dp,
1234 					      const struct drm_display_mode *mode)
1235 {
1236 	u8 lane_cnt = dp->mode.lane_cnt;
1237 	u32 reg, wpl;
1238 	unsigned int rate;
1239 
1240 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HTOTAL, mode->htotal);
1241 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VTOTAL, mode->vtotal);
1242 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_POLARITY,
1243 			(!!(mode->flags & DRM_MODE_FLAG_PVSYNC) <<
1244 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_VSYNC_SHIFT) |
1245 			(!!(mode->flags & DRM_MODE_FLAG_PHSYNC) <<
1246 			 ZYNQMP_DP_MAIN_STREAM_POLARITY_HSYNC_SHIFT));
1247 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSWIDTH,
1248 			mode->hsync_end - mode->hsync_start);
1249 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSWIDTH,
1250 			mode->vsync_end - mode->vsync_start);
1251 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HRES, mode->hdisplay);
1252 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VRES, mode->vdisplay);
1253 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_HSTART,
1254 			mode->htotal - mode->hsync_start);
1255 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_VSTART,
1256 			mode->vtotal - mode->vsync_start);
1257 
1258 	/* In synchronous mode, set the diviers */
1259 	if (dp->config.misc0 & ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK) {
1260 		reg = drm_dp_bw_code_to_link_rate(dp->mode.bw_code);
1261 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_N_VID, reg);
1262 		zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_M_VID, mode->clock);
1263 		rate = zynqmp_disp_get_audio_clk_rate(dp->dpsub->disp);
1264 		if (rate) {
1265 			dev_dbg(dp->dev, "Audio rate: %d\n", rate / 512);
1266 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_N_AUD, reg);
1267 			zynqmp_dp_write(dp, ZYNQMP_DP_TX_M_AUD, rate / 1000);
1268 		}
1269 	}
1270 
1271 	/* Only 2 channel audio is supported now */
1272 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1273 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CHANNELS, 1);
1274 
1275 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_PIX_WIDTH, 1);
1276 
1277 	/* Translate to the native 16 bit datapath based on IP core spec */
1278 	wpl = (mode->hdisplay * dp->config.bpp + 15) / 16;
1279 	reg = wpl + wpl % lane_cnt - lane_cnt;
1280 	zynqmp_dp_write(dp, ZYNQMP_DP_USER_DATA_COUNT_PER_LANE, reg);
1281 }
1282 
1283 /* -----------------------------------------------------------------------------
1284  * DRM Connector
1285  */
1286 
1287 static enum drm_connector_status
1288 zynqmp_dp_connector_detect(struct drm_connector *connector, bool force)
1289 {
1290 	struct zynqmp_dp *dp = connector_to_dp(connector);
1291 	struct zynqmp_dp_link_config *link_config = &dp->link_config;
1292 	u32 state, i;
1293 	int ret;
1294 
1295 	/*
1296 	 * This is from heuristic. It takes some delay (ex, 100 ~ 500 msec) to
1297 	 * get the HPD signal with some monitors.
1298 	 */
1299 	for (i = 0; i < 10; i++) {
1300 		state = zynqmp_dp_read(dp, ZYNQMP_DP_INTERRUPT_SIGNAL_STATE);
1301 		if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD)
1302 			break;
1303 		msleep(100);
1304 	}
1305 
1306 	if (state & ZYNQMP_DP_INTERRUPT_SIGNAL_STATE_HPD) {
1307 		ret = drm_dp_dpcd_read(&dp->aux, 0x0, dp->dpcd,
1308 				       sizeof(dp->dpcd));
1309 		if (ret < 0) {
1310 			dev_dbg(dp->dev, "DPCD read failed");
1311 			goto disconnected;
1312 		}
1313 
1314 		link_config->max_rate = min_t(int,
1315 					      drm_dp_max_link_rate(dp->dpcd),
1316 					      DP_HIGH_BIT_RATE2);
1317 		link_config->max_lanes = min_t(u8,
1318 					       drm_dp_max_lane_count(dp->dpcd),
1319 					       dp->num_lanes);
1320 
1321 		dp->status = connector_status_connected;
1322 		return connector_status_connected;
1323 	}
1324 
1325 disconnected:
1326 	dp->status = connector_status_disconnected;
1327 	return connector_status_disconnected;
1328 }
1329 
1330 static int zynqmp_dp_connector_get_modes(struct drm_connector *connector)
1331 {
1332 	struct zynqmp_dp *dp = connector_to_dp(connector);
1333 	struct edid *edid;
1334 	int ret;
1335 
1336 	edid = drm_get_edid(connector, &dp->aux.ddc);
1337 	if (!edid)
1338 		return 0;
1339 
1340 	drm_connector_update_edid_property(connector, edid);
1341 	ret = drm_add_edid_modes(connector, edid);
1342 	kfree(edid);
1343 
1344 	return ret;
1345 }
1346 
1347 static struct drm_encoder *
1348 zynqmp_dp_connector_best_encoder(struct drm_connector *connector)
1349 {
1350 	struct zynqmp_dp *dp = connector_to_dp(connector);
1351 
1352 	return &dp->encoder;
1353 }
1354 
1355 static int zynqmp_dp_connector_mode_valid(struct drm_connector *connector,
1356 					  struct drm_display_mode *mode)
1357 {
1358 	struct zynqmp_dp *dp = connector_to_dp(connector);
1359 	u8 max_lanes = dp->link_config.max_lanes;
1360 	u8 bpp = dp->config.bpp;
1361 	int max_rate = dp->link_config.max_rate;
1362 	int rate;
1363 
1364 	if (mode->clock > ZYNQMP_MAX_FREQ) {
1365 		dev_dbg(dp->dev, "filtered the mode, %s,for high pixel rate\n",
1366 			mode->name);
1367 		drm_mode_debug_printmodeline(mode);
1368 		return MODE_CLOCK_HIGH;
1369 	}
1370 
1371 	/* Check with link rate and lane count */
1372 	rate = zynqmp_dp_max_rate(max_rate, max_lanes, bpp);
1373 	if (mode->clock > rate) {
1374 		dev_dbg(dp->dev, "filtered the mode, %s,for high pixel rate\n",
1375 			mode->name);
1376 		drm_mode_debug_printmodeline(mode);
1377 		return MODE_CLOCK_HIGH;
1378 	}
1379 
1380 	return MODE_OK;
1381 }
1382 
1383 static const struct drm_connector_funcs zynqmp_dp_connector_funcs = {
1384 	.detect			= zynqmp_dp_connector_detect,
1385 	.fill_modes		= drm_helper_probe_single_connector_modes,
1386 	.destroy		= drm_connector_cleanup,
1387 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
1388 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
1389 	.reset			= drm_atomic_helper_connector_reset,
1390 };
1391 
1392 static const struct drm_connector_helper_funcs
1393 zynqmp_dp_connector_helper_funcs = {
1394 	.get_modes	= zynqmp_dp_connector_get_modes,
1395 	.best_encoder	= zynqmp_dp_connector_best_encoder,
1396 	.mode_valid	= zynqmp_dp_connector_mode_valid,
1397 };
1398 
1399 /* -----------------------------------------------------------------------------
1400  * DRM Encoder
1401  */
1402 
1403 static void zynqmp_dp_encoder_enable(struct drm_encoder *encoder)
1404 {
1405 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1406 	unsigned int i;
1407 	int ret = 0;
1408 
1409 	pm_runtime_get_sync(dp->dev);
1410 	dp->enabled = true;
1411 	zynqmp_dp_update_misc(dp);
1412 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1413 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 1);
1414 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, 0);
1415 	if (dp->status == connector_status_connected) {
1416 		for (i = 0; i < 3; i++) {
1417 			ret = drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER,
1418 						 DP_SET_POWER_D0);
1419 			if (ret == 1)
1420 				break;
1421 			usleep_range(300, 500);
1422 		}
1423 		/* Some monitors take time to wake up properly */
1424 		msleep(zynqmp_dp_power_on_delay_ms);
1425 	}
1426 	if (ret != 1)
1427 		dev_dbg(dp->dev, "DP aux failed\n");
1428 	else
1429 		zynqmp_dp_train_loop(dp);
1430 	zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET,
1431 			ZYNQMP_DP_SOFTWARE_RESET_ALL);
1432 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1);
1433 }
1434 
1435 static void zynqmp_dp_encoder_disable(struct drm_encoder *encoder)
1436 {
1437 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1438 
1439 	dp->enabled = false;
1440 	cancel_delayed_work(&dp->hpd_work);
1441 	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 0);
1442 	drm_dp_dpcd_writeb(&dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
1443 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1444 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1445 	if (zynqmp_disp_audio_enabled(dp->dpsub->disp))
1446 		zynqmp_dp_write(dp, ZYNQMP_DP_TX_AUDIO_CONTROL, 0);
1447 	pm_runtime_put_sync(dp->dev);
1448 }
1449 
1450 static void
1451 zynqmp_dp_encoder_atomic_mode_set(struct drm_encoder *encoder,
1452 				  struct drm_crtc_state *crtc_state,
1453 				  struct drm_connector_state *connector_state)
1454 {
1455 	struct zynqmp_dp *dp = encoder_to_dp(encoder);
1456 	struct drm_display_mode *mode = &crtc_state->mode;
1457 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1458 	u8 max_lanes = dp->link_config.max_lanes;
1459 	u8 bpp = dp->config.bpp;
1460 	int rate, max_rate = dp->link_config.max_rate;
1461 	int ret;
1462 
1463 	zynqmp_dp_set_format(dp, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1464 
1465 	/* Check again as bpp or format might have been chagned */
1466 	rate = zynqmp_dp_max_rate(max_rate, max_lanes, bpp);
1467 	if (mode->clock > rate) {
1468 		dev_err(dp->dev, "the mode, %s,has too high pixel rate\n",
1469 			mode->name);
1470 		drm_mode_debug_printmodeline(mode);
1471 	}
1472 
1473 	ret = zynqmp_dp_mode_configure(dp, adjusted_mode->clock, 0);
1474 	if (ret < 0)
1475 		return;
1476 
1477 	zynqmp_dp_encoder_mode_set_transfer_unit(dp, adjusted_mode);
1478 	zynqmp_dp_encoder_mode_set_stream(dp, adjusted_mode);
1479 }
1480 
1481 #define ZYNQMP_DP_MIN_H_BACKPORCH	20
1482 
1483 static int
1484 zynqmp_dp_encoder_atomic_check(struct drm_encoder *encoder,
1485 			       struct drm_crtc_state *crtc_state,
1486 			       struct drm_connector_state *conn_state)
1487 {
1488 	struct drm_display_mode *mode = &crtc_state->mode;
1489 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
1490 	int diff = mode->htotal - mode->hsync_end;
1491 
1492 	/*
1493 	 * ZynqMP DP requires horizontal backporch to be greater than 12.
1494 	 * This limitation may not be compatible with the sink device.
1495 	 */
1496 	if (diff < ZYNQMP_DP_MIN_H_BACKPORCH) {
1497 		int vrefresh = (adjusted_mode->clock * 1000) /
1498 			       (adjusted_mode->vtotal * adjusted_mode->htotal);
1499 
1500 		dev_dbg(encoder->dev->dev, "hbackporch adjusted: %d to %d",
1501 			diff, ZYNQMP_DP_MIN_H_BACKPORCH - diff);
1502 		diff = ZYNQMP_DP_MIN_H_BACKPORCH - diff;
1503 		adjusted_mode->htotal += diff;
1504 		adjusted_mode->clock = adjusted_mode->vtotal *
1505 				       adjusted_mode->htotal * vrefresh / 1000;
1506 	}
1507 
1508 	return 0;
1509 }
1510 
1511 static const struct drm_encoder_helper_funcs zynqmp_dp_encoder_helper_funcs = {
1512 	.enable			= zynqmp_dp_encoder_enable,
1513 	.disable		= zynqmp_dp_encoder_disable,
1514 	.atomic_mode_set	= zynqmp_dp_encoder_atomic_mode_set,
1515 	.atomic_check		= zynqmp_dp_encoder_atomic_check,
1516 };
1517 
1518 /* -----------------------------------------------------------------------------
1519  * Interrupt Handling
1520  */
1521 
1522 /**
1523  * zynqmp_dp_enable_vblank - Enable vblank
1524  * @dp: DisplayPort IP core structure
1525  *
1526  * Enable vblank interrupt
1527  */
1528 void zynqmp_dp_enable_vblank(struct zynqmp_dp *dp)
1529 {
1530 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_VBLANK_START);
1531 }
1532 
1533 /**
1534  * zynqmp_dp_disable_vblank - Disable vblank
1535  * @dp: DisplayPort IP core structure
1536  *
1537  * Disable vblank interrupt
1538  */
1539 void zynqmp_dp_disable_vblank(struct zynqmp_dp *dp)
1540 {
1541 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_VBLANK_START);
1542 }
1543 
1544 static void zynqmp_dp_hpd_work_func(struct work_struct *work)
1545 {
1546 	struct zynqmp_dp *dp;
1547 
1548 	dp = container_of(work, struct zynqmp_dp, hpd_work.work);
1549 
1550 	if (dp->drm)
1551 		drm_helper_hpd_irq_event(dp->drm);
1552 }
1553 
1554 static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data)
1555 {
1556 	struct zynqmp_dp *dp = (struct zynqmp_dp *)data;
1557 	u32 status, mask;
1558 
1559 	status = zynqmp_dp_read(dp, ZYNQMP_DP_INT_STATUS);
1560 	mask = zynqmp_dp_read(dp, ZYNQMP_DP_INT_MASK);
1561 	if (!(status & ~mask))
1562 		return IRQ_NONE;
1563 
1564 	/* dbg for diagnostic, but not much that the driver can do */
1565 	if (status & ZYNQMP_DP_INT_CHBUF_UNDERFLW_MASK)
1566 		dev_dbg_ratelimited(dp->dev, "underflow interrupt\n");
1567 	if (status & ZYNQMP_DP_INT_CHBUF_OVERFLW_MASK)
1568 		dev_dbg_ratelimited(dp->dev, "overflow interrupt\n");
1569 
1570 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_STATUS, status);
1571 
1572 	if (status & ZYNQMP_DP_INT_VBLANK_START)
1573 		zynqmp_disp_handle_vblank(dp->dpsub->disp);
1574 
1575 	if (status & ZYNQMP_DP_INT_HPD_EVENT)
1576 		schedule_delayed_work(&dp->hpd_work, 0);
1577 
1578 	if (status & ZYNQMP_DP_INT_HPD_IRQ) {
1579 		int ret;
1580 		u8 status[DP_LINK_STATUS_SIZE + 2];
1581 
1582 		ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
1583 				       DP_LINK_STATUS_SIZE + 2);
1584 		if (ret < 0)
1585 			goto handled;
1586 
1587 		if (status[4] & DP_LINK_STATUS_UPDATED ||
1588 		    !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) ||
1589 		    !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) {
1590 			zynqmp_dp_train_loop(dp);
1591 		}
1592 	}
1593 
1594 handled:
1595 	return IRQ_HANDLED;
1596 }
1597 
1598 /* -----------------------------------------------------------------------------
1599  * Initialization & Cleanup
1600  */
1601 
1602 int zynqmp_dp_drm_init(struct zynqmp_dpsub *dpsub)
1603 {
1604 	struct zynqmp_dp *dp = dpsub->dp;
1605 	struct drm_encoder *encoder = &dp->encoder;
1606 	struct drm_connector *connector = &dp->connector;
1607 	int ret;
1608 
1609 	dp->config.misc0 &= ~ZYNQMP_DP_MAIN_STREAM_MISC0_SYNC_LOCK;
1610 	zynqmp_dp_set_format(dp, ZYNQMP_DPSUB_FORMAT_RGB, 8);
1611 
1612 	/* Create the DRM encoder and connector. */
1613 	encoder->possible_crtcs |= zynqmp_disp_get_crtc_mask(dpsub->disp);
1614 	drm_simple_encoder_init(dp->drm, encoder, DRM_MODE_ENCODER_TMDS);
1615 	drm_encoder_helper_add(encoder, &zynqmp_dp_encoder_helper_funcs);
1616 
1617 	connector->polled = DRM_CONNECTOR_POLL_HPD;
1618 	ret = drm_connector_init(encoder->dev, connector,
1619 				 &zynqmp_dp_connector_funcs,
1620 				 DRM_MODE_CONNECTOR_DisplayPort);
1621 	if (ret) {
1622 		dev_err(dp->dev, "failed to create the DRM connector\n");
1623 		return ret;
1624 	}
1625 
1626 	drm_connector_helper_add(connector, &zynqmp_dp_connector_helper_funcs);
1627 	drm_connector_register(connector);
1628 	drm_connector_attach_encoder(connector, encoder);
1629 
1630 	/* Initialize and register the AUX adapter. */
1631 	ret = zynqmp_dp_aux_init(dp);
1632 	if (ret) {
1633 		dev_err(dp->dev, "failed to initialize DP aux\n");
1634 		return ret;
1635 	}
1636 
1637 	/* Now that initialisation is complete, enable interrupts. */
1638 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_EN, ZYNQMP_DP_INT_ALL);
1639 
1640 	return 0;
1641 }
1642 
1643 int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm)
1644 {
1645 	struct platform_device *pdev = to_platform_device(dpsub->dev);
1646 	struct zynqmp_dp *dp;
1647 	struct resource *res;
1648 	int ret;
1649 
1650 	dp = drmm_kzalloc(drm, sizeof(*dp), GFP_KERNEL);
1651 	if (!dp)
1652 		return -ENOMEM;
1653 
1654 	dp->dev = &pdev->dev;
1655 	dp->dpsub = dpsub;
1656 	dp->status = connector_status_disconnected;
1657 	dp->drm = drm;
1658 
1659 	INIT_DELAYED_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func);
1660 
1661 	dpsub->dp = dp;
1662 
1663 	/* Acquire all resources (IOMEM, IRQ and PHYs). */
1664 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp");
1665 	dp->iomem = devm_ioremap_resource(dp->dev, res);
1666 	if (IS_ERR(dp->iomem))
1667 		return PTR_ERR(dp->iomem);
1668 
1669 	dp->irq = platform_get_irq(pdev, 0);
1670 	if (dp->irq < 0)
1671 		return dp->irq;
1672 
1673 	dp->reset = devm_reset_control_get(dp->dev, NULL);
1674 	if (IS_ERR(dp->reset)) {
1675 		if (PTR_ERR(dp->reset) != -EPROBE_DEFER)
1676 			dev_err(dp->dev, "failed to get reset: %ld\n",
1677 				PTR_ERR(dp->reset));
1678 		return PTR_ERR(dp->reset);
1679 	}
1680 
1681 	ret = zynqmp_dp_reset(dp, false);
1682 	if (ret < 0)
1683 		return ret;
1684 
1685 	ret = zynqmp_dp_phy_probe(dp);
1686 	if (ret)
1687 		goto err_reset;
1688 
1689 	/* Initialize the hardware. */
1690 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
1691 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);
1692 	zynqmp_dp_set(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET);
1693 	zynqmp_dp_write(dp, ZYNQMP_DP_FORCE_SCRAMBLER_RESET, 1);
1694 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1695 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1696 
1697 	ret = zynqmp_dp_phy_init(dp);
1698 	if (ret)
1699 		goto err_reset;
1700 
1701 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1);
1702 
1703 	/*
1704 	 * Now that the hardware is initialized and won't generate spurious
1705 	 * interrupts, request the IRQ.
1706 	 */
1707 	ret = devm_request_threaded_irq(dp->dev, dp->irq, NULL,
1708 					zynqmp_dp_irq_handler, IRQF_ONESHOT,
1709 					dev_name(dp->dev), dp);
1710 	if (ret < 0)
1711 		goto err_phy_exit;
1712 
1713 	dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n",
1714 		dp->num_lanes);
1715 
1716 	return 0;
1717 
1718 err_phy_exit:
1719 	zynqmp_dp_phy_exit(dp);
1720 err_reset:
1721 	zynqmp_dp_reset(dp, true);
1722 
1723 	return ret;
1724 }
1725 
1726 void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub)
1727 {
1728 	struct zynqmp_dp *dp = dpsub->dp;
1729 
1730 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL);
1731 	disable_irq(dp->irq);
1732 
1733 	cancel_delayed_work_sync(&dp->hpd_work);
1734 	zynqmp_dp_aux_cleanup(dp);
1735 
1736 	zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);
1737 	zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff);
1738 
1739 	zynqmp_dp_phy_exit(dp);
1740 	zynqmp_dp_reset(dp, true);
1741 }
1742