1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * TPD12S015 HDMI ESD protection & level shifter chip driver
  4 *
  5 * Copyright (C) 2019 Texas Instruments Incorporated
  6 *
  7 * Based on the omapdrm-specific encoder-opa362 driver
  8 *
  9 * Copyright (C) 2013 Texas Instruments Incorporated
 10 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
 11 */
 12
 13#include <linux/delay.h>
 14#include <linux/gpio/consumer.h>
 15#include <linux/interrupt.h>
 16#include <linux/module.h>
 17#include <linux/mutex.h>
 18#include <linux/of.h>
 19#include <linux/of_graph.h>
 20#include <linux/platform_device.h>
 21
 22#include <drm/drm_bridge.h>
 23
 24struct tpd12s015_device {
 25	struct drm_bridge bridge;
 26
 27	struct gpio_desc *ct_cp_hpd_gpio;
 28	struct gpio_desc *ls_oe_gpio;
 29	struct gpio_desc *hpd_gpio;
 30	int hpd_irq;
 31
 32	struct drm_bridge *next_bridge;
 33};
 34
 35static inline struct tpd12s015_device *to_tpd12s015(struct drm_bridge *bridge)
 36{
 37	return container_of(bridge, struct tpd12s015_device, bridge);
 38}
 39
 40static int tpd12s015_attach(struct drm_bridge *bridge,
 41			    enum drm_bridge_attach_flags flags)
 42{
 43	struct tpd12s015_device *tpd = to_tpd12s015(bridge);
 44	int ret;
 45
 46	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
 47		return -EINVAL;
 48
 49	ret = drm_bridge_attach(bridge->encoder, tpd->next_bridge,
 50				bridge, flags);
 51	if (ret < 0)
 52		return ret;
 53
 54	gpiod_set_value_cansleep(tpd->ls_oe_gpio, 1);
 55
 56	/* DC-DC converter needs at max 300us to get to 90% of 5V. */
 57	usleep_range(300, 1000);
 58
 59	return 0;
 60}
 61
 62static void tpd12s015_detach(struct drm_bridge *bridge)
 63{
 64	struct tpd12s015_device *tpd = to_tpd12s015(bridge);
 65
 66	gpiod_set_value_cansleep(tpd->ls_oe_gpio, 0);
 67}
 68
 69static enum drm_connector_status tpd12s015_detect(struct drm_bridge *bridge)
 70{
 71	struct tpd12s015_device *tpd = to_tpd12s015(bridge);
 72
 73	if (gpiod_get_value_cansleep(tpd->hpd_gpio))
 74		return connector_status_connected;
 75	else
 76		return connector_status_disconnected;
 77}
 78
 79static void tpd12s015_hpd_enable(struct drm_bridge *bridge)
 80{
 81	struct tpd12s015_device *tpd = to_tpd12s015(bridge);
 82
 83	gpiod_set_value_cansleep(tpd->ct_cp_hpd_gpio, 1);
 84}
 85
 86static void tpd12s015_hpd_disable(struct drm_bridge *bridge)
 87{
 88	struct tpd12s015_device *tpd = to_tpd12s015(bridge);
 89
 90	gpiod_set_value_cansleep(tpd->ct_cp_hpd_gpio, 0);
 91}
 92
 93static const struct drm_bridge_funcs tpd12s015_bridge_funcs = {
 94	.attach			= tpd12s015_attach,
 95	.detach			= tpd12s015_detach,
 96	.detect			= tpd12s015_detect,
 97	.hpd_enable		= tpd12s015_hpd_enable,
 98	.hpd_disable		= tpd12s015_hpd_disable,
 99};
100
101static irqreturn_t tpd12s015_hpd_isr(int irq, void *data)
102{
103	struct tpd12s015_device *tpd = data;
104	struct drm_bridge *bridge = &tpd->bridge;
105
106	drm_bridge_hpd_notify(bridge, tpd12s015_detect(bridge));
107
108	return IRQ_HANDLED;
109}
110
111static int tpd12s015_probe(struct platform_device *pdev)
112{
113	struct tpd12s015_device *tpd;
114	struct device_node *node;
115	struct gpio_desc *gpio;
116	int ret;
117
118	tpd = devm_kzalloc(&pdev->dev, sizeof(*tpd), GFP_KERNEL);
119	if (!tpd)
120		return -ENOMEM;
121
122	platform_set_drvdata(pdev, tpd);
123
124	tpd->bridge.funcs = &tpd12s015_bridge_funcs;
125	tpd->bridge.of_node = pdev->dev.of_node;
126	tpd->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
127	tpd->bridge.ops = DRM_BRIDGE_OP_DETECT;
128
129	/* Get the next bridge, connected to port@1. */
130	node = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
131	if (!node)
132		return -ENODEV;
133
134	tpd->next_bridge = of_drm_find_bridge(node);
135	of_node_put(node);
136
137	if (!tpd->next_bridge)
138		return -EPROBE_DEFER;
139
140	/* Get the control and HPD GPIOs. */
141	gpio = devm_gpiod_get_index_optional(&pdev->dev, NULL, 0,
142					     GPIOD_OUT_LOW);
143	if (IS_ERR(gpio))
144		return PTR_ERR(gpio);
145
146	tpd->ct_cp_hpd_gpio = gpio;
147
148	gpio = devm_gpiod_get_index_optional(&pdev->dev, NULL, 1,
149					     GPIOD_OUT_LOW);
150	if (IS_ERR(gpio))
151		return PTR_ERR(gpio);
152
153	tpd->ls_oe_gpio = gpio;
154
155	gpio = devm_gpiod_get_index(&pdev->dev, NULL, 2, GPIOD_IN);
156	if (IS_ERR(gpio))
157		return PTR_ERR(gpio);
158
159	tpd->hpd_gpio = gpio;
160
161	/* Register the IRQ if the HPD GPIO is IRQ-capable. */
162	tpd->hpd_irq = gpiod_to_irq(tpd->hpd_gpio);
163	if (tpd->hpd_irq >= 0) {
164		ret = devm_request_threaded_irq(&pdev->dev, tpd->hpd_irq, NULL,
165						tpd12s015_hpd_isr,
166						IRQF_TRIGGER_RISING |
167						IRQF_TRIGGER_FALLING |
168						IRQF_ONESHOT,
169						"tpd12s015 hpd", tpd);
170		if (ret)
171			return ret;
172
173		tpd->bridge.ops |= DRM_BRIDGE_OP_HPD;
174	}
175
176	/* Register the DRM bridge. */
177	drm_bridge_add(&tpd->bridge);
178
179	return 0;
180}
181
182static int __exit tpd12s015_remove(struct platform_device *pdev)
183{
184	struct tpd12s015_device *tpd = platform_get_drvdata(pdev);
185
186	drm_bridge_remove(&tpd->bridge);
187
188	return 0;
189}
190
191static const struct of_device_id tpd12s015_of_match[] = {
192	{ .compatible = "ti,tpd12s015", },
193	{},
194};
195
196MODULE_DEVICE_TABLE(of, tpd12s015_of_match);
197
198static struct platform_driver tpd12s015_driver = {
199	.probe	= tpd12s015_probe,
200	.remove	= __exit_p(tpd12s015_remove),
201	.driver	= {
202		.name	= "tpd12s015",
203		.of_match_table = tpd12s015_of_match,
204	},
205};
206
207module_platform_driver(tpd12s015_driver);
208
209MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
210MODULE_DESCRIPTION("TPD12S015 HDMI level shifter and ESD protection driver");
211MODULE_LICENSE("GPL");