cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ti-tpd12s015.c (5046B)


      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");