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 unsigned long 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,
69 writel(value, dpaux->regs + (offset << 2));
72 static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8 *buffer,
77 for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
78 size_t num = min_t(size_t, size - i * 4, 4);
79 unsigned long value = 0;
81 for (j = 0; j < num; j++)
82 value |= buffer[i * 4 + j] << (j * 8);
84 tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXDATA_WRITE(i));
88 static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
93 for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
94 size_t num = min_t(size_t, size - i * 4, 4);
97 value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
99 for (j = 0; j < num; j++)
100 buffer[i * 4 + j] = value >> (j * 8);
104 static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,
105 struct drm_dp_aux_msg *msg)
107 unsigned long timeout = msecs_to_jiffies(250);
108 struct tegra_dpaux *dpaux = to_dpaux(aux);
109 unsigned long status;
113 /* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */
118 * Allow zero-sized messages only for I2C, in which case they specify
119 * address-only transactions.
122 switch (msg->request & ~DP_AUX_I2C_MOT) {
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_STATUS:
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 int tegra_dpaux_probe(struct platform_device *pdev)
272 struct tegra_dpaux *dpaux;
273 struct resource *regs;
277 dpaux = devm_kzalloc(&pdev->dev, sizeof(*dpaux), GFP_KERNEL);
281 INIT_WORK(&dpaux->work, tegra_dpaux_hotplug);
282 init_completion(&dpaux->complete);
283 INIT_LIST_HEAD(&dpaux->list);
284 dpaux->dev = &pdev->dev;
286 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
287 dpaux->regs = devm_ioremap_resource(&pdev->dev, regs);
288 if (IS_ERR(dpaux->regs))
289 return PTR_ERR(dpaux->regs);
291 dpaux->irq = platform_get_irq(pdev, 0);
292 if (dpaux->irq < 0) {
293 dev_err(&pdev->dev, "failed to get IRQ\n");
297 dpaux->rst = devm_reset_control_get(&pdev->dev, "dpaux");
298 if (IS_ERR(dpaux->rst))
299 return PTR_ERR(dpaux->rst);
301 dpaux->clk = devm_clk_get(&pdev->dev, NULL);
302 if (IS_ERR(dpaux->clk))
303 return PTR_ERR(dpaux->clk);
305 err = clk_prepare_enable(dpaux->clk);
309 reset_control_deassert(dpaux->rst);
311 dpaux->clk_parent = devm_clk_get(&pdev->dev, "parent");
312 if (IS_ERR(dpaux->clk_parent))
313 return PTR_ERR(dpaux->clk_parent);
315 err = clk_prepare_enable(dpaux->clk_parent);
319 err = clk_set_rate(dpaux->clk_parent, 270000000);
321 dev_err(&pdev->dev, "failed to set clock to 270 MHz: %d\n",
326 dpaux->vdd = devm_regulator_get(&pdev->dev, "vdd");
327 if (IS_ERR(dpaux->vdd))
328 return PTR_ERR(dpaux->vdd);
330 err = devm_request_irq(dpaux->dev, dpaux->irq, tegra_dpaux_irq, 0,
331 dev_name(dpaux->dev), dpaux);
333 dev_err(dpaux->dev, "failed to request IRQ#%u: %d\n",
338 dpaux->aux.transfer = tegra_dpaux_transfer;
339 dpaux->aux.dev = &pdev->dev;
341 err = drm_dp_aux_register(&dpaux->aux);
345 /* enable and clear all interrupts */
346 value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |
347 DPAUX_INTR_UNPLUG_EVENT | DPAUX_INTR_PLUG_EVENT;
348 tegra_dpaux_writel(dpaux, value, DPAUX_INTR_EN_AUX);
349 tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
351 mutex_lock(&dpaux_lock);
352 list_add_tail(&dpaux->list, &dpaux_list);
353 mutex_unlock(&dpaux_lock);
355 platform_set_drvdata(pdev, dpaux);
360 static int tegra_dpaux_remove(struct platform_device *pdev)
362 struct tegra_dpaux *dpaux = platform_get_drvdata(pdev);
364 drm_dp_aux_unregister(&dpaux->aux);
366 mutex_lock(&dpaux_lock);
367 list_del(&dpaux->list);
368 mutex_unlock(&dpaux_lock);
370 cancel_work_sync(&dpaux->work);
372 clk_disable_unprepare(dpaux->clk_parent);
373 reset_control_assert(dpaux->rst);
374 clk_disable_unprepare(dpaux->clk);
379 static const struct of_device_id tegra_dpaux_of_match[] = {
380 { .compatible = "nvidia,tegra124-dpaux", },
383 MODULE_DEVICE_TABLE(of, tegra_dpaux_of_match);
385 struct platform_driver tegra_dpaux_driver = {
387 .name = "tegra-dpaux",
388 .of_match_table = tegra_dpaux_of_match,
390 .probe = tegra_dpaux_probe,
391 .remove = tegra_dpaux_remove,
394 struct tegra_dpaux *tegra_dpaux_find_by_of_node(struct device_node *np)
396 struct tegra_dpaux *dpaux;
398 mutex_lock(&dpaux_lock);
400 list_for_each_entry(dpaux, &dpaux_list, list)
401 if (np == dpaux->dev->of_node) {
402 mutex_unlock(&dpaux_lock);
406 mutex_unlock(&dpaux_lock);
411 int tegra_dpaux_attach(struct tegra_dpaux *dpaux, struct tegra_output *output)
413 unsigned long timeout;
416 output->connector.polled = DRM_CONNECTOR_POLL_HPD;
417 dpaux->output = output;
419 err = regulator_enable(dpaux->vdd);
423 timeout = jiffies + msecs_to_jiffies(250);
425 while (time_before(jiffies, timeout)) {
426 enum drm_connector_status status;
428 status = tegra_dpaux_detect(dpaux);
429 if (status == connector_status_connected)
432 usleep_range(1000, 2000);
438 int tegra_dpaux_detach(struct tegra_dpaux *dpaux)
440 unsigned long timeout;
443 err = regulator_disable(dpaux->vdd);
447 timeout = jiffies + msecs_to_jiffies(250);
449 while (time_before(jiffies, timeout)) {
450 enum drm_connector_status status;
452 status = tegra_dpaux_detect(dpaux);
453 if (status == connector_status_disconnected) {
454 dpaux->output = NULL;
458 usleep_range(1000, 2000);
464 enum drm_connector_status tegra_dpaux_detect(struct tegra_dpaux *dpaux)
468 value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
470 if (value & DPAUX_DP_AUXSTAT_HPD_STATUS)
471 return connector_status_connected;
473 return connector_status_disconnected;
476 int tegra_dpaux_enable(struct tegra_dpaux *dpaux)
480 value = DPAUX_HYBRID_PADCTL_AUX_CMH(2) |
481 DPAUX_HYBRID_PADCTL_AUX_DRVZ(4) |
482 DPAUX_HYBRID_PADCTL_AUX_DRVI(0x18) |
483 DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
484 DPAUX_HYBRID_PADCTL_MODE_AUX;
485 tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
487 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
488 value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
489 tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
494 int tegra_dpaux_disable(struct tegra_dpaux *dpaux)
498 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
499 value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
500 tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
505 int tegra_dpaux_prepare(struct tegra_dpaux *dpaux, u8 encoding)
509 err = drm_dp_dpcd_writeb(&dpaux->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
517 int tegra_dpaux_train(struct tegra_dpaux *dpaux, struct drm_dp_link *link,
520 u8 tp = pattern & DP_TRAINING_PATTERN_MASK;
521 u8 status[DP_LINK_STATUS_SIZE], values[4];
525 err = drm_dp_dpcd_writeb(&dpaux->aux, DP_TRAINING_PATTERN_SET, pattern);
529 if (tp == DP_TRAINING_PATTERN_DISABLE)
532 for (i = 0; i < link->num_lanes; i++)
533 values[i] = DP_TRAIN_MAX_PRE_EMPHASIS_REACHED |
534 DP_TRAIN_PRE_EMPH_LEVEL_0 |
535 DP_TRAIN_MAX_SWING_REACHED |
536 DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
538 err = drm_dp_dpcd_write(&dpaux->aux, DP_TRAINING_LANE0_SET, values,
543 usleep_range(500, 1000);
545 err = drm_dp_dpcd_read_link_status(&dpaux->aux, status);
550 case DP_TRAINING_PATTERN_1:
551 if (!drm_dp_clock_recovery_ok(status, link->num_lanes))
556 case DP_TRAINING_PATTERN_2:
557 if (!drm_dp_channel_eq_ok(status, link->num_lanes))
563 dev_err(dpaux->dev, "unsupported training pattern %u\n", tp);
567 err = drm_dp_dpcd_writeb(&dpaux->aux, DP_EDP_CONFIGURATION_SET, 0);