2 * Copyright (C) 2013 NVIDIA Corporation
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
10 #include <linux/delay.h>
11 #include <linux/gpio.h>
12 #include <linux/interrupt.h>
14 #include <linux/of_gpio.h>
15 #include <linux/platform_device.h>
16 #include <linux/reset.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/workqueue.h>
20 #include <drm/drm_dp_helper.h>
21 #include <drm/drm_panel.h>
26 static DEFINE_MUTEX(dpaux_lock);
27 static LIST_HEAD(dpaux_list);
30 struct drm_dp_aux aux;
36 struct tegra_output *output;
38 struct reset_control *rst;
39 struct clk *clk_parent;
42 struct regulator *vdd;
44 struct completion complete;
45 struct work_struct work;
46 struct list_head list;
49 static inline struct tegra_dpaux *to_dpaux(struct drm_dp_aux *aux)
51 return container_of(aux, struct tegra_dpaux, aux);
54 static inline struct tegra_dpaux *work_to_dpaux(struct work_struct *work)
56 return container_of(work, struct tegra_dpaux, work);
59 static inline u32 tegra_dpaux_readl(struct tegra_dpaux *dpaux,
62 return readl(dpaux->regs + (offset << 2));
65 static inline void tegra_dpaux_writel(struct tegra_dpaux *dpaux,
66 u32 value, unsigned long offset)
68 writel(value, dpaux->regs + (offset << 2));
71 static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8 *buffer,
76 for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
77 size_t num = min_t(size_t, size - i * 4, 4);
80 for (j = 0; j < num; j++)
81 value |= buffer[i * 4 + j] << (j * 8);
83 tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXDATA_WRITE(i));
87 static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
92 for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
93 size_t num = min_t(size_t, size - i * 4, 4);
96 value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
98 for (j = 0; j < num; j++)
99 buffer[i * 4 + j] = value >> (j * 8);
103 static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,
104 struct drm_dp_aux_msg *msg)
106 unsigned long timeout = msecs_to_jiffies(250);
107 struct tegra_dpaux *dpaux = to_dpaux(aux);
108 unsigned long status;
112 /* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */
117 * Allow zero-sized messages only for I2C, in which case they specify
118 * address-only transactions.
121 switch (msg->request & ~DP_AUX_I2C_MOT) {
122 case DP_AUX_I2C_WRITE_STATUS_UPDATE:
123 case DP_AUX_I2C_WRITE:
124 case DP_AUX_I2C_READ:
125 value = DPAUX_DP_AUXCTL_CMD_ADDRESS_ONLY;
132 /* For non-zero-sized messages, set the CMDLEN field. */
133 value = DPAUX_DP_AUXCTL_CMDLEN(msg->size - 1);
136 switch (msg->request & ~DP_AUX_I2C_MOT) {
137 case DP_AUX_I2C_WRITE:
138 if (msg->request & DP_AUX_I2C_MOT)
139 value |= DPAUX_DP_AUXCTL_CMD_MOT_WR;
141 value |= DPAUX_DP_AUXCTL_CMD_I2C_WR;
145 case DP_AUX_I2C_READ:
146 if (msg->request & DP_AUX_I2C_MOT)
147 value |= DPAUX_DP_AUXCTL_CMD_MOT_RD;
149 value |= DPAUX_DP_AUXCTL_CMD_I2C_RD;
153 case DP_AUX_I2C_WRITE_STATUS_UPDATE:
154 if (msg->request & DP_AUX_I2C_MOT)
155 value |= DPAUX_DP_AUXCTL_CMD_MOT_RQ;
157 value |= DPAUX_DP_AUXCTL_CMD_I2C_RQ;
161 case DP_AUX_NATIVE_WRITE:
162 value |= DPAUX_DP_AUXCTL_CMD_AUX_WR;
165 case DP_AUX_NATIVE_READ:
166 value |= DPAUX_DP_AUXCTL_CMD_AUX_RD;
173 tegra_dpaux_writel(dpaux, msg->address, DPAUX_DP_AUXADDR);
174 tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
176 if ((msg->request & DP_AUX_I2C_READ) == 0) {
177 tegra_dpaux_write_fifo(dpaux, msg->buffer, msg->size);
181 /* start transaction */
182 value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXCTL);
183 value |= DPAUX_DP_AUXCTL_TRANSACTREQ;
184 tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
186 status = wait_for_completion_timeout(&dpaux->complete, timeout);
190 /* read status and clear errors */
191 value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
192 tegra_dpaux_writel(dpaux, 0xf00, DPAUX_DP_AUXSTAT);
194 if (value & DPAUX_DP_AUXSTAT_TIMEOUT_ERROR)
197 if ((value & DPAUX_DP_AUXSTAT_RX_ERROR) ||
198 (value & DPAUX_DP_AUXSTAT_SINKSTAT_ERROR) ||
199 (value & DPAUX_DP_AUXSTAT_NO_STOP_ERROR))
202 switch ((value & DPAUX_DP_AUXSTAT_REPLY_TYPE_MASK) >> 16) {
204 msg->reply = DP_AUX_NATIVE_REPLY_ACK;
208 msg->reply = DP_AUX_NATIVE_REPLY_NACK;
212 msg->reply = DP_AUX_NATIVE_REPLY_DEFER;
216 msg->reply = DP_AUX_I2C_REPLY_NACK;
220 msg->reply = DP_AUX_I2C_REPLY_DEFER;
224 if ((msg->size > 0) && (msg->reply == DP_AUX_NATIVE_REPLY_ACK)) {
225 if (msg->request & DP_AUX_I2C_READ) {
226 size_t count = value & DPAUX_DP_AUXSTAT_REPLY_MASK;
228 if (WARN_ON(count != msg->size))
229 count = min_t(size_t, count, msg->size);
231 tegra_dpaux_read_fifo(dpaux, msg->buffer, count);
239 static void tegra_dpaux_hotplug(struct work_struct *work)
241 struct tegra_dpaux *dpaux = work_to_dpaux(work);
244 drm_helper_hpd_irq_event(dpaux->output->connector.dev);
247 static irqreturn_t tegra_dpaux_irq(int irq, void *data)
249 struct tegra_dpaux *dpaux = data;
250 irqreturn_t ret = IRQ_HANDLED;
253 /* clear interrupts */
254 value = tegra_dpaux_readl(dpaux, DPAUX_INTR_AUX);
255 tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
257 if (value & (DPAUX_INTR_PLUG_EVENT | DPAUX_INTR_UNPLUG_EVENT))
258 schedule_work(&dpaux->work);
260 if (value & DPAUX_INTR_IRQ_EVENT) {
261 /* TODO: handle this */
264 if (value & DPAUX_INTR_AUX_DONE)
265 complete(&dpaux->complete);
270 static void tegra_dpaux_pad_power_down(struct tegra_dpaux *dpaux)
272 u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
274 value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
276 tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
279 static void tegra_dpaux_pad_power_up(struct tegra_dpaux *dpaux)
281 u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
283 value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
285 tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
288 static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)
293 case DPAUX_HYBRID_PADCTL_MODE_AUX:
294 value = DPAUX_HYBRID_PADCTL_AUX_CMH(2) |
295 DPAUX_HYBRID_PADCTL_AUX_DRVZ(4) |
296 DPAUX_HYBRID_PADCTL_AUX_DRVI(0x18) |
297 DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
298 DPAUX_HYBRID_PADCTL_MODE_AUX;
301 case DPAUX_HYBRID_PADCTL_MODE_I2C:
302 value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |
303 DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
304 DPAUX_HYBRID_PADCTL_MODE_I2C;
311 tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
312 tegra_dpaux_pad_power_up(dpaux);
317 static int tegra_dpaux_probe(struct platform_device *pdev)
319 struct tegra_dpaux *dpaux;
320 struct resource *regs;
324 dpaux = devm_kzalloc(&pdev->dev, sizeof(*dpaux), GFP_KERNEL);
328 INIT_WORK(&dpaux->work, tegra_dpaux_hotplug);
329 init_completion(&dpaux->complete);
330 INIT_LIST_HEAD(&dpaux->list);
331 dpaux->dev = &pdev->dev;
333 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
334 dpaux->regs = devm_ioremap_resource(&pdev->dev, regs);
335 if (IS_ERR(dpaux->regs))
336 return PTR_ERR(dpaux->regs);
338 dpaux->irq = platform_get_irq(pdev, 0);
339 if (dpaux->irq < 0) {
340 dev_err(&pdev->dev, "failed to get IRQ\n");
344 if (!pdev->dev.pm_domain) {
345 dpaux->rst = devm_reset_control_get(&pdev->dev, "dpaux");
346 if (IS_ERR(dpaux->rst)) {
348 "failed to get reset control: %ld\n",
349 PTR_ERR(dpaux->rst));
350 return PTR_ERR(dpaux->rst);
354 dpaux->clk = devm_clk_get(&pdev->dev, NULL);
355 if (IS_ERR(dpaux->clk)) {
356 dev_err(&pdev->dev, "failed to get module clock: %ld\n",
357 PTR_ERR(dpaux->clk));
358 return PTR_ERR(dpaux->clk);
361 err = clk_prepare_enable(dpaux->clk);
363 dev_err(&pdev->dev, "failed to enable module clock: %d\n",
369 reset_control_deassert(dpaux->rst);
371 dpaux->clk_parent = devm_clk_get(&pdev->dev, "parent");
372 if (IS_ERR(dpaux->clk_parent)) {
373 dev_err(&pdev->dev, "failed to get parent clock: %ld\n",
374 PTR_ERR(dpaux->clk_parent));
375 err = PTR_ERR(dpaux->clk_parent);
379 err = clk_prepare_enable(dpaux->clk_parent);
381 dev_err(&pdev->dev, "failed to enable parent clock: %d\n",
386 err = clk_set_rate(dpaux->clk_parent, 270000000);
388 dev_err(&pdev->dev, "failed to set clock to 270 MHz: %d\n",
390 goto disable_parent_clk;
393 dpaux->vdd = devm_regulator_get(&pdev->dev, "vdd");
394 if (IS_ERR(dpaux->vdd)) {
395 dev_err(&pdev->dev, "failed to get VDD supply: %ld\n",
396 PTR_ERR(dpaux->vdd));
397 err = PTR_ERR(dpaux->vdd);
398 goto disable_parent_clk;
401 err = devm_request_irq(dpaux->dev, dpaux->irq, tegra_dpaux_irq, 0,
402 dev_name(dpaux->dev), dpaux);
404 dev_err(dpaux->dev, "failed to request IRQ#%u: %d\n",
406 goto disable_parent_clk;
409 disable_irq(dpaux->irq);
411 dpaux->aux.transfer = tegra_dpaux_transfer;
412 dpaux->aux.dev = &pdev->dev;
414 err = drm_dp_aux_register(&dpaux->aux);
416 goto disable_parent_clk;
419 * Assume that by default the DPAUX/I2C pads will be used for HDMI,
420 * so power them up and configure them in I2C mode.
422 * The DPAUX code paths reconfigure the pads in AUX mode, but there
423 * is no possibility to perform the I2C mode configuration in the
426 err = tegra_dpaux_pad_config(dpaux, DPAUX_HYBRID_PADCTL_MODE_I2C);
430 /* enable and clear all interrupts */
431 value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |
432 DPAUX_INTR_UNPLUG_EVENT | DPAUX_INTR_PLUG_EVENT;
433 tegra_dpaux_writel(dpaux, value, DPAUX_INTR_EN_AUX);
434 tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
436 mutex_lock(&dpaux_lock);
437 list_add_tail(&dpaux->list, &dpaux_list);
438 mutex_unlock(&dpaux_lock);
440 platform_set_drvdata(pdev, dpaux);
445 clk_disable_unprepare(dpaux->clk_parent);
448 reset_control_assert(dpaux->rst);
450 clk_disable_unprepare(dpaux->clk);
455 static int tegra_dpaux_remove(struct platform_device *pdev)
457 struct tegra_dpaux *dpaux = platform_get_drvdata(pdev);
459 /* make sure pads are powered down when not in use */
460 tegra_dpaux_pad_power_down(dpaux);
462 drm_dp_aux_unregister(&dpaux->aux);
464 mutex_lock(&dpaux_lock);
465 list_del(&dpaux->list);
466 mutex_unlock(&dpaux_lock);
468 cancel_work_sync(&dpaux->work);
470 clk_disable_unprepare(dpaux->clk_parent);
473 reset_control_assert(dpaux->rst);
475 clk_disable_unprepare(dpaux->clk);
480 static const struct of_device_id tegra_dpaux_of_match[] = {
481 { .compatible = "nvidia,tegra210-dpaux", },
482 { .compatible = "nvidia,tegra124-dpaux", },
485 MODULE_DEVICE_TABLE(of, tegra_dpaux_of_match);
487 struct platform_driver tegra_dpaux_driver = {
489 .name = "tegra-dpaux",
490 .of_match_table = tegra_dpaux_of_match,
492 .probe = tegra_dpaux_probe,
493 .remove = tegra_dpaux_remove,
496 struct drm_dp_aux *drm_dp_aux_find_by_of_node(struct device_node *np)
498 struct tegra_dpaux *dpaux;
500 mutex_lock(&dpaux_lock);
502 list_for_each_entry(dpaux, &dpaux_list, list)
503 if (np == dpaux->dev->of_node) {
504 mutex_unlock(&dpaux_lock);
508 mutex_unlock(&dpaux_lock);
513 int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output)
515 struct tegra_dpaux *dpaux = to_dpaux(aux);
516 unsigned long timeout;
519 output->connector.polled = DRM_CONNECTOR_POLL_HPD;
520 dpaux->output = output;
522 err = regulator_enable(dpaux->vdd);
526 timeout = jiffies + msecs_to_jiffies(250);
528 while (time_before(jiffies, timeout)) {
529 enum drm_connector_status status;
531 status = drm_dp_aux_detect(aux);
532 if (status == connector_status_connected) {
533 enable_irq(dpaux->irq);
537 usleep_range(1000, 2000);
543 int drm_dp_aux_detach(struct drm_dp_aux *aux)
545 struct tegra_dpaux *dpaux = to_dpaux(aux);
546 unsigned long timeout;
549 disable_irq(dpaux->irq);
551 err = regulator_disable(dpaux->vdd);
555 timeout = jiffies + msecs_to_jiffies(250);
557 while (time_before(jiffies, timeout)) {
558 enum drm_connector_status status;
560 status = drm_dp_aux_detect(aux);
561 if (status == connector_status_disconnected) {
562 dpaux->output = NULL;
566 usleep_range(1000, 2000);
572 enum drm_connector_status drm_dp_aux_detect(struct drm_dp_aux *aux)
574 struct tegra_dpaux *dpaux = to_dpaux(aux);
577 value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
579 if (value & DPAUX_DP_AUXSTAT_HPD_STATUS)
580 return connector_status_connected;
582 return connector_status_disconnected;
585 int drm_dp_aux_enable(struct drm_dp_aux *aux)
587 struct tegra_dpaux *dpaux = to_dpaux(aux);
589 return tegra_dpaux_pad_config(dpaux, DPAUX_HYBRID_PADCTL_MODE_AUX);
592 int drm_dp_aux_disable(struct drm_dp_aux *aux)
594 struct tegra_dpaux *dpaux = to_dpaux(aux);
596 tegra_dpaux_pad_power_down(dpaux);
601 int drm_dp_aux_prepare(struct drm_dp_aux *aux, u8 encoding)
605 err = drm_dp_dpcd_writeb(aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
613 int drm_dp_aux_train(struct drm_dp_aux *aux, struct drm_dp_link *link,
616 u8 tp = pattern & DP_TRAINING_PATTERN_MASK;
617 u8 status[DP_LINK_STATUS_SIZE], values[4];
621 err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET, pattern);
625 if (tp == DP_TRAINING_PATTERN_DISABLE)
628 for (i = 0; i < link->num_lanes; i++)
629 values[i] = DP_TRAIN_MAX_PRE_EMPHASIS_REACHED |
630 DP_TRAIN_PRE_EMPH_LEVEL_0 |
631 DP_TRAIN_MAX_SWING_REACHED |
632 DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
634 err = drm_dp_dpcd_write(aux, DP_TRAINING_LANE0_SET, values,
639 usleep_range(500, 1000);
641 err = drm_dp_dpcd_read_link_status(aux, status);
646 case DP_TRAINING_PATTERN_1:
647 if (!drm_dp_clock_recovery_ok(status, link->num_lanes))
652 case DP_TRAINING_PATTERN_2:
653 if (!drm_dp_channel_eq_ok(status, link->num_lanes))
659 dev_err(aux->dev, "unsupported training pattern %u\n", tp);
663 err = drm_dp_dpcd_writeb(aux, DP_EDP_CONFIGURATION_SET, 0);