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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2013 NVIDIA Corporation4 */5 6#include <linux/clk.h>7#include <linux/delay.h>8#include <linux/interrupt.h>9#include <linux/io.h>10#include <linux/module.h>11#include <linux/of.h>12#include <linux/pinctrl/pinconf-generic.h>13#include <linux/pinctrl/pinctrl.h>14#include <linux/pinctrl/pinmux.h>15#include <linux/platform_device.h>16#include <linux/pm_runtime.h>17#include <linux/regulator/consumer.h>18#include <linux/reset.h>19#include <linux/workqueue.h>20 21#include <drm/display/drm_dp_helper.h>22#include <drm/display/drm_dp_aux_bus.h>23#include <drm/drm_panel.h>24 25#include "dp.h"26#include "dpaux.h"27#include "drm.h"28#include "trace.h"29 30static DEFINE_MUTEX(dpaux_lock);31static LIST_HEAD(dpaux_list);32 33struct tegra_dpaux_soc {34	unsigned int cmh;35	unsigned int drvz;36	unsigned int drvi;37};38 39struct tegra_dpaux {40	struct drm_dp_aux aux;41	struct device *dev;42 43	const struct tegra_dpaux_soc *soc;44 45	void __iomem *regs;46	int irq;47 48	struct tegra_output *output;49 50	struct reset_control *rst;51	struct clk *clk_parent;52	struct clk *clk;53 54	struct regulator *vdd;55 56	struct completion complete;57	struct work_struct work;58	struct list_head list;59 60#ifdef CONFIG_GENERIC_PINCONF61	struct pinctrl_dev *pinctrl;62	struct pinctrl_desc desc;63#endif64};65 66static inline struct tegra_dpaux *to_dpaux(struct drm_dp_aux *aux)67{68	return container_of(aux, struct tegra_dpaux, aux);69}70 71static inline struct tegra_dpaux *work_to_dpaux(struct work_struct *work)72{73	return container_of(work, struct tegra_dpaux, work);74}75 76static inline u32 tegra_dpaux_readl(struct tegra_dpaux *dpaux,77				    unsigned int offset)78{79	u32 value = readl(dpaux->regs + (offset << 2));80 81	trace_dpaux_readl(dpaux->dev, offset, value);82 83	return value;84}85 86static inline void tegra_dpaux_writel(struct tegra_dpaux *dpaux,87				      u32 value, unsigned int offset)88{89	trace_dpaux_writel(dpaux->dev, offset, value);90	writel(value, dpaux->regs + (offset << 2));91}92 93static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8 *buffer,94				   size_t size)95{96	size_t i, j;97 98	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {99		size_t num = min_t(size_t, size - i * 4, 4);100		u32 value = 0;101 102		for (j = 0; j < num; j++)103			value |= buffer[i * 4 + j] << (j * 8);104 105		tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXDATA_WRITE(i));106	}107}108 109static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,110				  size_t size)111{112	size_t i, j;113 114	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {115		size_t num = min_t(size_t, size - i * 4, 4);116		u32 value;117 118		value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));119 120		for (j = 0; j < num; j++)121			buffer[i * 4 + j] = value >> (j * 8);122	}123}124 125static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,126				    struct drm_dp_aux_msg *msg)127{128	unsigned long timeout = msecs_to_jiffies(250);129	struct tegra_dpaux *dpaux = to_dpaux(aux);130	unsigned long status;131	ssize_t ret = 0;132	u8 reply = 0;133	u32 value;134 135	/* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */136	if (msg->size > 16)137		return -EINVAL;138 139	/*140	 * Allow zero-sized messages only for I2C, in which case they specify141	 * address-only transactions.142	 */143	if (msg->size < 1) {144		switch (msg->request & ~DP_AUX_I2C_MOT) {145		case DP_AUX_I2C_WRITE_STATUS_UPDATE:146		case DP_AUX_I2C_WRITE:147		case DP_AUX_I2C_READ:148			value = DPAUX_DP_AUXCTL_CMD_ADDRESS_ONLY;149			break;150 151		default:152			return -EINVAL;153		}154	} else {155		/* For non-zero-sized messages, set the CMDLEN field. */156		value = DPAUX_DP_AUXCTL_CMDLEN(msg->size - 1);157	}158 159	switch (msg->request & ~DP_AUX_I2C_MOT) {160	case DP_AUX_I2C_WRITE:161		if (msg->request & DP_AUX_I2C_MOT)162			value |= DPAUX_DP_AUXCTL_CMD_MOT_WR;163		else164			value |= DPAUX_DP_AUXCTL_CMD_I2C_WR;165 166		break;167 168	case DP_AUX_I2C_READ:169		if (msg->request & DP_AUX_I2C_MOT)170			value |= DPAUX_DP_AUXCTL_CMD_MOT_RD;171		else172			value |= DPAUX_DP_AUXCTL_CMD_I2C_RD;173 174		break;175 176	case DP_AUX_I2C_WRITE_STATUS_UPDATE:177		if (msg->request & DP_AUX_I2C_MOT)178			value |= DPAUX_DP_AUXCTL_CMD_MOT_RQ;179		else180			value |= DPAUX_DP_AUXCTL_CMD_I2C_RQ;181 182		break;183 184	case DP_AUX_NATIVE_WRITE:185		value |= DPAUX_DP_AUXCTL_CMD_AUX_WR;186		break;187 188	case DP_AUX_NATIVE_READ:189		value |= DPAUX_DP_AUXCTL_CMD_AUX_RD;190		break;191 192	default:193		return -EINVAL;194	}195 196	tegra_dpaux_writel(dpaux, msg->address, DPAUX_DP_AUXADDR);197	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);198 199	if ((msg->request & DP_AUX_I2C_READ) == 0) {200		tegra_dpaux_write_fifo(dpaux, msg->buffer, msg->size);201		ret = msg->size;202	}203 204	/* start transaction */205	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXCTL);206	value |= DPAUX_DP_AUXCTL_TRANSACTREQ;207	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);208 209	status = wait_for_completion_timeout(&dpaux->complete, timeout);210	if (!status)211		return -ETIMEDOUT;212 213	/* read status and clear errors */214	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);215	tegra_dpaux_writel(dpaux, 0xf00, DPAUX_DP_AUXSTAT);216 217	if (value & DPAUX_DP_AUXSTAT_TIMEOUT_ERROR)218		return -ETIMEDOUT;219 220	if ((value & DPAUX_DP_AUXSTAT_RX_ERROR) ||221	    (value & DPAUX_DP_AUXSTAT_SINKSTAT_ERROR) ||222	    (value & DPAUX_DP_AUXSTAT_NO_STOP_ERROR))223		return -EIO;224 225	switch ((value & DPAUX_DP_AUXSTAT_REPLY_TYPE_MASK) >> 16) {226	case 0x00:227		reply = DP_AUX_NATIVE_REPLY_ACK;228		break;229 230	case 0x01:231		reply = DP_AUX_NATIVE_REPLY_NACK;232		break;233 234	case 0x02:235		reply = DP_AUX_NATIVE_REPLY_DEFER;236		break;237 238	case 0x04:239		reply = DP_AUX_I2C_REPLY_NACK;240		break;241 242	case 0x08:243		reply = DP_AUX_I2C_REPLY_DEFER;244		break;245	}246 247	if ((msg->size > 0) && (msg->reply == DP_AUX_NATIVE_REPLY_ACK)) {248		if (msg->request & DP_AUX_I2C_READ) {249			size_t count = value & DPAUX_DP_AUXSTAT_REPLY_MASK;250 251			/*252			 * There might be a smarter way to do this, but since253			 * the DP helpers will already retry transactions for254			 * an -EBUSY return value, simply reuse that instead.255			 */256			if (count != msg->size) {257				ret = -EBUSY;258				goto out;259			}260 261			tegra_dpaux_read_fifo(dpaux, msg->buffer, count);262			ret = count;263		}264	}265 266	msg->reply = reply;267 268out:269	return ret;270}271 272static void tegra_dpaux_hotplug(struct work_struct *work)273{274	struct tegra_dpaux *dpaux = work_to_dpaux(work);275 276	if (dpaux->output)277		drm_helper_hpd_irq_event(dpaux->output->connector.dev);278}279 280static irqreturn_t tegra_dpaux_irq(int irq, void *data)281{282	struct tegra_dpaux *dpaux = data;283	u32 value;284 285	/* clear interrupts */286	value = tegra_dpaux_readl(dpaux, DPAUX_INTR_AUX);287	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);288 289	if (value & (DPAUX_INTR_PLUG_EVENT | DPAUX_INTR_UNPLUG_EVENT))290		schedule_work(&dpaux->work);291 292	if (value & DPAUX_INTR_IRQ_EVENT) {293		/* TODO: handle this */294	}295 296	if (value & DPAUX_INTR_AUX_DONE)297		complete(&dpaux->complete);298 299	return IRQ_HANDLED;300}301 302enum tegra_dpaux_functions {303	DPAUX_PADCTL_FUNC_AUX,304	DPAUX_PADCTL_FUNC_I2C,305	DPAUX_PADCTL_FUNC_OFF,306};307 308static void tegra_dpaux_pad_power_down(struct tegra_dpaux *dpaux)309{310	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);311 312	value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;313 314	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);315}316 317static void tegra_dpaux_pad_power_up(struct tegra_dpaux *dpaux)318{319	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);320 321	value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;322 323	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);324}325 326static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)327{328	u32 value;329 330	switch (function) {331	case DPAUX_PADCTL_FUNC_AUX:332		value = DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |333			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |334			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |335			DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |336			DPAUX_HYBRID_PADCTL_MODE_AUX;337		break;338 339	case DPAUX_PADCTL_FUNC_I2C:340		value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |341			DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |342			DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |343			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |344			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |345			DPAUX_HYBRID_PADCTL_MODE_I2C;346		break;347 348	case DPAUX_PADCTL_FUNC_OFF:349		tegra_dpaux_pad_power_down(dpaux);350		return 0;351 352	default:353		return -ENOTSUPP;354	}355 356	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);357	tegra_dpaux_pad_power_up(dpaux);358 359	return 0;360}361 362#ifdef CONFIG_GENERIC_PINCONF363static const struct pinctrl_pin_desc tegra_dpaux_pins[] = {364	PINCTRL_PIN(0, "DP_AUX_CHx_P"),365	PINCTRL_PIN(1, "DP_AUX_CHx_N"),366};367 368static const unsigned tegra_dpaux_pin_numbers[] = { 0, 1 };369 370static const char * const tegra_dpaux_groups[] = {371	"dpaux-io",372};373 374static const char * const tegra_dpaux_functions[] = {375	"aux",376	"i2c",377	"off",378};379 380static int tegra_dpaux_get_groups_count(struct pinctrl_dev *pinctrl)381{382	return ARRAY_SIZE(tegra_dpaux_groups);383}384 385static const char *tegra_dpaux_get_group_name(struct pinctrl_dev *pinctrl,386					      unsigned int group)387{388	return tegra_dpaux_groups[group];389}390 391static int tegra_dpaux_get_group_pins(struct pinctrl_dev *pinctrl,392				      unsigned group, const unsigned **pins,393				      unsigned *num_pins)394{395	*pins = tegra_dpaux_pin_numbers;396	*num_pins = ARRAY_SIZE(tegra_dpaux_pin_numbers);397 398	return 0;399}400 401static const struct pinctrl_ops tegra_dpaux_pinctrl_ops = {402	.get_groups_count = tegra_dpaux_get_groups_count,403	.get_group_name = tegra_dpaux_get_group_name,404	.get_group_pins = tegra_dpaux_get_group_pins,405	.dt_node_to_map = pinconf_generic_dt_node_to_map_group,406	.dt_free_map = pinconf_generic_dt_free_map,407};408 409static int tegra_dpaux_get_functions_count(struct pinctrl_dev *pinctrl)410{411	return ARRAY_SIZE(tegra_dpaux_functions);412}413 414static const char *tegra_dpaux_get_function_name(struct pinctrl_dev *pinctrl,415						 unsigned int function)416{417	return tegra_dpaux_functions[function];418}419 420static int tegra_dpaux_get_function_groups(struct pinctrl_dev *pinctrl,421					   unsigned int function,422					   const char * const **groups,423					   unsigned * const num_groups)424{425	*num_groups = ARRAY_SIZE(tegra_dpaux_groups);426	*groups = tegra_dpaux_groups;427 428	return 0;429}430 431static int tegra_dpaux_set_mux(struct pinctrl_dev *pinctrl,432			       unsigned int function, unsigned int group)433{434	struct tegra_dpaux *dpaux = pinctrl_dev_get_drvdata(pinctrl);435 436	return tegra_dpaux_pad_config(dpaux, function);437}438 439static const struct pinmux_ops tegra_dpaux_pinmux_ops = {440	.get_functions_count = tegra_dpaux_get_functions_count,441	.get_function_name = tegra_dpaux_get_function_name,442	.get_function_groups = tegra_dpaux_get_function_groups,443	.set_mux = tegra_dpaux_set_mux,444};445#endif446 447static int tegra_dpaux_probe(struct platform_device *pdev)448{449	struct tegra_dpaux *dpaux;450	u32 value;451	int err;452 453	dpaux = devm_kzalloc(&pdev->dev, sizeof(*dpaux), GFP_KERNEL);454	if (!dpaux)455		return -ENOMEM;456 457	dpaux->soc = of_device_get_match_data(&pdev->dev);458	INIT_WORK(&dpaux->work, tegra_dpaux_hotplug);459	init_completion(&dpaux->complete);460	INIT_LIST_HEAD(&dpaux->list);461	dpaux->dev = &pdev->dev;462 463	dpaux->regs = devm_platform_ioremap_resource(pdev, 0);464	if (IS_ERR(dpaux->regs))465		return PTR_ERR(dpaux->regs);466 467	dpaux->irq = platform_get_irq(pdev, 0);468	if (dpaux->irq < 0)469		return dpaux->irq;470 471	if (!pdev->dev.pm_domain) {472		dpaux->rst = devm_reset_control_get(&pdev->dev, "dpaux");473		if (IS_ERR(dpaux->rst)) {474			dev_err(&pdev->dev,475				"failed to get reset control: %ld\n",476				PTR_ERR(dpaux->rst));477			return PTR_ERR(dpaux->rst);478		}479	}480 481	dpaux->clk = devm_clk_get(&pdev->dev, NULL);482	if (IS_ERR(dpaux->clk)) {483		dev_err(&pdev->dev, "failed to get module clock: %ld\n",484			PTR_ERR(dpaux->clk));485		return PTR_ERR(dpaux->clk);486	}487 488	dpaux->clk_parent = devm_clk_get(&pdev->dev, "parent");489	if (IS_ERR(dpaux->clk_parent)) {490		dev_err(&pdev->dev, "failed to get parent clock: %ld\n",491			PTR_ERR(dpaux->clk_parent));492		return PTR_ERR(dpaux->clk_parent);493	}494 495	err = clk_set_rate(dpaux->clk_parent, 270000000);496	if (err < 0) {497		dev_err(&pdev->dev, "failed to set clock to 270 MHz: %d\n",498			err);499		return err;500	}501 502	dpaux->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");503	if (IS_ERR(dpaux->vdd)) {504		if (PTR_ERR(dpaux->vdd) != -ENODEV) {505			if (PTR_ERR(dpaux->vdd) != -EPROBE_DEFER)506				dev_err(&pdev->dev,507					"failed to get VDD supply: %ld\n",508					PTR_ERR(dpaux->vdd));509 510			return PTR_ERR(dpaux->vdd);511		}512 513		dpaux->vdd = NULL;514	}515 516	platform_set_drvdata(pdev, dpaux);517	pm_runtime_enable(&pdev->dev);518	pm_runtime_get_sync(&pdev->dev);519 520	err = devm_request_irq(dpaux->dev, dpaux->irq, tegra_dpaux_irq, 0,521			       dev_name(dpaux->dev), dpaux);522	if (err < 0) {523		dev_err(dpaux->dev, "failed to request IRQ#%u: %d\n",524			dpaux->irq, err);525		goto err_pm_disable;526	}527 528	disable_irq(dpaux->irq);529 530	dpaux->aux.transfer = tegra_dpaux_transfer;531	dpaux->aux.dev = &pdev->dev;532 533	drm_dp_aux_init(&dpaux->aux);534 535	/*536	 * Assume that by default the DPAUX/I2C pads will be used for HDMI,537	 * so power them up and configure them in I2C mode.538	 *539	 * The DPAUX code paths reconfigure the pads in AUX mode, but there540	 * is no possibility to perform the I2C mode configuration in the541	 * HDMI path.542	 */543	err = tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_I2C);544	if (err < 0)545		goto err_pm_disable;546 547#ifdef CONFIG_GENERIC_PINCONF548	dpaux->desc.name = dev_name(&pdev->dev);549	dpaux->desc.pins = tegra_dpaux_pins;550	dpaux->desc.npins = ARRAY_SIZE(tegra_dpaux_pins);551	dpaux->desc.pctlops = &tegra_dpaux_pinctrl_ops;552	dpaux->desc.pmxops = &tegra_dpaux_pinmux_ops;553	dpaux->desc.owner = THIS_MODULE;554 555	dpaux->pinctrl = devm_pinctrl_register(&pdev->dev, &dpaux->desc, dpaux);556	if (IS_ERR(dpaux->pinctrl)) {557		dev_err(&pdev->dev, "failed to register pincontrol\n");558		err = PTR_ERR(dpaux->pinctrl);559		goto err_pm_disable;560	}561#endif562	/* enable and clear all interrupts */563	value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |564		DPAUX_INTR_UNPLUG_EVENT | DPAUX_INTR_PLUG_EVENT;565	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_EN_AUX);566	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);567 568	mutex_lock(&dpaux_lock);569	list_add_tail(&dpaux->list, &dpaux_list);570	mutex_unlock(&dpaux_lock);571 572	err = devm_of_dp_aux_populate_ep_devices(&dpaux->aux);573	if (err < 0) {574		dev_err(dpaux->dev, "failed to populate AUX bus: %d\n", err);575		goto err_pm_disable;576	}577 578	return 0;579 580err_pm_disable:581	pm_runtime_put_sync(&pdev->dev);582	pm_runtime_disable(&pdev->dev);583	return err;584}585 586static void tegra_dpaux_remove(struct platform_device *pdev)587{588	struct tegra_dpaux *dpaux = platform_get_drvdata(pdev);589 590	cancel_work_sync(&dpaux->work);591 592	/* make sure pads are powered down when not in use */593	tegra_dpaux_pad_power_down(dpaux);594 595	pm_runtime_put_sync(&pdev->dev);596	pm_runtime_disable(&pdev->dev);597 598	mutex_lock(&dpaux_lock);599	list_del(&dpaux->list);600	mutex_unlock(&dpaux_lock);601}602 603static int tegra_dpaux_suspend(struct device *dev)604{605	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);606	int err = 0;607 608	if (dpaux->rst) {609		err = reset_control_assert(dpaux->rst);610		if (err < 0) {611			dev_err(dev, "failed to assert reset: %d\n", err);612			return err;613		}614	}615 616	usleep_range(1000, 2000);617 618	clk_disable_unprepare(dpaux->clk_parent);619	clk_disable_unprepare(dpaux->clk);620 621	return err;622}623 624static int tegra_dpaux_resume(struct device *dev)625{626	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);627	int err;628 629	err = clk_prepare_enable(dpaux->clk);630	if (err < 0) {631		dev_err(dev, "failed to enable clock: %d\n", err);632		return err;633	}634 635	err = clk_prepare_enable(dpaux->clk_parent);636	if (err < 0) {637		dev_err(dev, "failed to enable parent clock: %d\n", err);638		goto disable_clk;639	}640 641	usleep_range(1000, 2000);642 643	if (dpaux->rst) {644		err = reset_control_deassert(dpaux->rst);645		if (err < 0) {646			dev_err(dev, "failed to deassert reset: %d\n", err);647			goto disable_parent;648		}649 650		usleep_range(1000, 2000);651	}652 653	return 0;654 655disable_parent:656	clk_disable_unprepare(dpaux->clk_parent);657disable_clk:658	clk_disable_unprepare(dpaux->clk);659	return err;660}661 662static const struct dev_pm_ops tegra_dpaux_pm_ops = {663	RUNTIME_PM_OPS(tegra_dpaux_suspend, tegra_dpaux_resume, NULL)664};665 666static const struct tegra_dpaux_soc tegra124_dpaux_soc = {667	.cmh = 0x02,668	.drvz = 0x04,669	.drvi = 0x18,670};671 672static const struct tegra_dpaux_soc tegra210_dpaux_soc = {673	.cmh = 0x02,674	.drvz = 0x04,675	.drvi = 0x30,676};677 678static const struct tegra_dpaux_soc tegra194_dpaux_soc = {679	.cmh = 0x02,680	.drvz = 0x04,681	.drvi = 0x2c,682};683 684static const struct of_device_id tegra_dpaux_of_match[] = {685	{ .compatible = "nvidia,tegra194-dpaux", .data = &tegra194_dpaux_soc },686	{ .compatible = "nvidia,tegra186-dpaux", .data = &tegra210_dpaux_soc },687	{ .compatible = "nvidia,tegra210-dpaux", .data = &tegra210_dpaux_soc },688	{ .compatible = "nvidia,tegra124-dpaux", .data = &tegra124_dpaux_soc },689	{ },690};691MODULE_DEVICE_TABLE(of, tegra_dpaux_of_match);692 693struct platform_driver tegra_dpaux_driver = {694	.driver = {695		.name = "tegra-dpaux",696		.of_match_table = tegra_dpaux_of_match,697		.pm = pm_ptr(&tegra_dpaux_pm_ops),698	},699	.probe = tegra_dpaux_probe,700	.remove_new = tegra_dpaux_remove,701};702 703struct drm_dp_aux *drm_dp_aux_find_by_of_node(struct device_node *np)704{705	struct tegra_dpaux *dpaux;706 707	mutex_lock(&dpaux_lock);708 709	list_for_each_entry(dpaux, &dpaux_list, list)710		if (np == dpaux->dev->of_node) {711			mutex_unlock(&dpaux_lock);712			return &dpaux->aux;713		}714 715	mutex_unlock(&dpaux_lock);716 717	return NULL;718}719 720int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output)721{722	struct tegra_dpaux *dpaux = to_dpaux(aux);723	unsigned long timeout;724	int err;725 726	aux->drm_dev = output->connector.dev;727	err = drm_dp_aux_register(aux);728	if (err < 0)729		return err;730 731	output->connector.polled = DRM_CONNECTOR_POLL_HPD;732	dpaux->output = output;733 734	if (output->panel) {735		enum drm_connector_status status;736 737		if (dpaux->vdd) {738			err = regulator_enable(dpaux->vdd);739			if (err < 0)740				return err;741		}742 743		timeout = jiffies + msecs_to_jiffies(250);744 745		while (time_before(jiffies, timeout)) {746			status = drm_dp_aux_detect(aux);747 748			if (status == connector_status_connected)749				break;750 751			usleep_range(1000, 2000);752		}753 754		if (status != connector_status_connected)755			return -ETIMEDOUT;756	}757 758	enable_irq(dpaux->irq);759	return 0;760}761 762int drm_dp_aux_detach(struct drm_dp_aux *aux)763{764	struct tegra_dpaux *dpaux = to_dpaux(aux);765	unsigned long timeout;766	int err;767 768	drm_dp_aux_unregister(aux);769	disable_irq(dpaux->irq);770 771	if (dpaux->output->panel) {772		enum drm_connector_status status;773 774		if (dpaux->vdd) {775			err = regulator_disable(dpaux->vdd);776			if (err < 0)777				return err;778		}779 780		timeout = jiffies + msecs_to_jiffies(250);781 782		while (time_before(jiffies, timeout)) {783			status = drm_dp_aux_detect(aux);784 785			if (status == connector_status_disconnected)786				break;787 788			usleep_range(1000, 2000);789		}790 791		if (status != connector_status_disconnected)792			return -ETIMEDOUT;793 794		dpaux->output = NULL;795	}796 797	return 0;798}799 800enum drm_connector_status drm_dp_aux_detect(struct drm_dp_aux *aux)801{802	struct tegra_dpaux *dpaux = to_dpaux(aux);803	u32 value;804 805	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);806 807	if (value & DPAUX_DP_AUXSTAT_HPD_STATUS)808		return connector_status_connected;809 810	return connector_status_disconnected;811}812 813int drm_dp_aux_enable(struct drm_dp_aux *aux)814{815	struct tegra_dpaux *dpaux = to_dpaux(aux);816 817	return tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_AUX);818}819 820int drm_dp_aux_disable(struct drm_dp_aux *aux)821{822	struct tegra_dpaux *dpaux = to_dpaux(aux);823 824	tegra_dpaux_pad_power_down(dpaux);825 826	return 0;827}828