linux-stable/drivers/gpu/drm/bridge/thc63lvd1024.c
Mark Brown a1bc5e3145 drm/bridge: thc63lvd1024: Fix regulator_get_optional() misuse
The thc63lvd1024 driver requests a supply using regulator_get_optional()
but both the name of the supply and the usage pattern suggest that it is
being used for the main power for the device and is not at all optional
for the device for function, there is no handling at all for absent
supplies.  Such regulators should use the vanilla regulator_get()
interface, it will ensure that even if a supply is not described in the
system integration one will be provided in software.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
2021-01-05 07:19:48 +02:00

260 lines
5.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* THC63LVD1024 LVDS to parallel data DRM bridge driver.
*
* Copyright (C) 2018 Jacopo Mondi <jacopo+renesas@jmondi.org>
*/
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <drm/drm_bridge.h>
#include <drm/drm_panel.h>
enum thc63_ports {
THC63_LVDS_IN0,
THC63_LVDS_IN1,
THC63_RGB_OUT0,
THC63_RGB_OUT1,
};
struct thc63_dev {
struct device *dev;
struct regulator *vcc;
struct gpio_desc *pdwn;
struct gpio_desc *oe;
struct drm_bridge bridge;
struct drm_bridge *next;
struct drm_bridge_timings timings;
};
static inline struct thc63_dev *to_thc63(struct drm_bridge *bridge)
{
return container_of(bridge, struct thc63_dev, bridge);
}
static int thc63_attach(struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags)
{
struct thc63_dev *thc63 = to_thc63(bridge);
return drm_bridge_attach(bridge->encoder, thc63->next, bridge, flags);
}
static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge,
const struct drm_display_info *info,
const struct drm_display_mode *mode)
{
struct thc63_dev *thc63 = to_thc63(bridge);
unsigned int min_freq;
unsigned int max_freq;
/*
* The THC63LVD1024 pixel rate range is 8 to 135 MHz in all modes but
* dual-in, single-out where it is 40 to 150 MHz. As dual-in, dual-out
* isn't supported by the driver yet, simply derive the limits from the
* input mode.
*/
if (thc63->timings.dual_link) {
min_freq = 40000;
max_freq = 150000;
} else {
min_freq = 8000;
max_freq = 135000;
}
if (mode->clock < min_freq)
return MODE_CLOCK_LOW;
if (mode->clock > max_freq)
return MODE_CLOCK_HIGH;
return MODE_OK;
}
static void thc63_enable(struct drm_bridge *bridge)
{
struct thc63_dev *thc63 = to_thc63(bridge);
int ret;
ret = regulator_enable(thc63->vcc);
if (ret) {
dev_err(thc63->dev,
"Failed to enable regulator \"vcc\": %d\n", ret);
return;
}
gpiod_set_value(thc63->pdwn, 0);
gpiod_set_value(thc63->oe, 1);
}
static void thc63_disable(struct drm_bridge *bridge)
{
struct thc63_dev *thc63 = to_thc63(bridge);
int ret;
gpiod_set_value(thc63->oe, 0);
gpiod_set_value(thc63->pdwn, 1);
ret = regulator_disable(thc63->vcc);
if (ret)
dev_err(thc63->dev,
"Failed to disable regulator \"vcc\": %d\n", ret);
}
static const struct drm_bridge_funcs thc63_bridge_func = {
.attach = thc63_attach,
.mode_valid = thc63_mode_valid,
.enable = thc63_enable,
.disable = thc63_disable,
};
static int thc63_parse_dt(struct thc63_dev *thc63)
{
struct device_node *endpoint;
struct device_node *remote;
endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
THC63_RGB_OUT0, -1);
if (!endpoint) {
dev_err(thc63->dev, "Missing endpoint in port@%u\n",
THC63_RGB_OUT0);
return -ENODEV;
}
remote = of_graph_get_remote_port_parent(endpoint);
of_node_put(endpoint);
if (!remote) {
dev_err(thc63->dev, "Endpoint in port@%u unconnected\n",
THC63_RGB_OUT0);
return -ENODEV;
}
if (!of_device_is_available(remote)) {
dev_err(thc63->dev, "port@%u remote endpoint is disabled\n",
THC63_RGB_OUT0);
of_node_put(remote);
return -ENODEV;
}
thc63->next = of_drm_find_bridge(remote);
of_node_put(remote);
if (!thc63->next)
return -EPROBE_DEFER;
endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
THC63_LVDS_IN1, -1);
if (endpoint) {
remote = of_graph_get_remote_port_parent(endpoint);
of_node_put(endpoint);
if (remote) {
if (of_device_is_available(remote))
thc63->timings.dual_link = true;
of_node_put(remote);
}
}
dev_dbg(thc63->dev, "operating in %s-link mode\n",
thc63->timings.dual_link ? "dual" : "single");
return 0;
}
static int thc63_gpio_init(struct thc63_dev *thc63)
{
thc63->oe = devm_gpiod_get_optional(thc63->dev, "oe", GPIOD_OUT_LOW);
if (IS_ERR(thc63->oe)) {
dev_err(thc63->dev, "Unable to get \"oe-gpios\": %ld\n",
PTR_ERR(thc63->oe));
return PTR_ERR(thc63->oe);
}
thc63->pdwn = devm_gpiod_get_optional(thc63->dev, "powerdown",
GPIOD_OUT_HIGH);
if (IS_ERR(thc63->pdwn)) {
dev_err(thc63->dev, "Unable to get \"powerdown-gpios\": %ld\n",
PTR_ERR(thc63->pdwn));
return PTR_ERR(thc63->pdwn);
}
return 0;
}
static int thc63_probe(struct platform_device *pdev)
{
struct thc63_dev *thc63;
int ret;
thc63 = devm_kzalloc(&pdev->dev, sizeof(*thc63), GFP_KERNEL);
if (!thc63)
return -ENOMEM;
thc63->dev = &pdev->dev;
platform_set_drvdata(pdev, thc63);
thc63->vcc = devm_regulator_get(thc63->dev, "vcc");
if (IS_ERR(thc63->vcc)) {
if (PTR_ERR(thc63->vcc) == -EPROBE_DEFER)
return -EPROBE_DEFER;
dev_err(thc63->dev, "Unable to get \"vcc\" supply: %ld\n",
PTR_ERR(thc63->vcc));
return PTR_ERR(thc63->vcc);
}
ret = thc63_gpio_init(thc63);
if (ret)
return ret;
ret = thc63_parse_dt(thc63);
if (ret)
return ret;
thc63->bridge.driver_private = thc63;
thc63->bridge.of_node = pdev->dev.of_node;
thc63->bridge.funcs = &thc63_bridge_func;
thc63->bridge.timings = &thc63->timings;
drm_bridge_add(&thc63->bridge);
return 0;
}
static int thc63_remove(struct platform_device *pdev)
{
struct thc63_dev *thc63 = platform_get_drvdata(pdev);
drm_bridge_remove(&thc63->bridge);
return 0;
}
static const struct of_device_id thc63_match[] = {
{ .compatible = "thine,thc63lvd1024", },
{ },
};
MODULE_DEVICE_TABLE(of, thc63_match);
static struct platform_driver thc63_driver = {
.probe = thc63_probe,
.remove = thc63_remove,
.driver = {
.name = "thc63lvd1024",
.of_match_table = thc63_match,
},
};
module_platform_driver(thc63_driver);
MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
MODULE_DESCRIPTION("Thine THC63LVD1024 LVDS decoder DRM bridge driver");
MODULE_LICENSE("GPL v2");