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// SPDX-License-Identifier: GPL-2.0-only
/*
* NXP PTN3460 DP/LVDS bridge driver
*
* Copyright (C) 2013 Google, Inc.
*/
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#define PTN3460_EDID_ADDR 0x0
#define PTN3460_EDID_EMULATION_ADDR 0x84
#define PTN3460_EDID_ENABLE_EMULATION 0
#define PTN3460_EDID_EMULATION_SELECTION 1
#define PTN3460_EDID_SRAM_LOAD_ADDR 0x85
struct ptn3460_bridge {
struct drm_connector connector;
struct i2c_client *client;
struct drm_bridge bridge;
struct drm_bridge *panel_bridge;
struct gpio_desc *gpio_pd_n;
struct gpio_desc *gpio_rst_n;
u32 edid_emulation;
bool enabled;
};
static inline struct ptn3460_bridge *
bridge_to_ptn3460(struct drm_bridge *bridge)
{
return container_of(bridge, struct ptn3460_bridge, bridge);
}
static inline struct ptn3460_bridge *
connector_to_ptn3460(struct drm_connector *connector)
{
return container_of(connector, struct ptn3460_bridge, connector);
}
static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
u8 *buf, int len)
{
int ret;
ret = i2c_master_send(ptn_bridge->client, &addr, 1);
if (ret <= 0) {
DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
return ret;
}
ret = i2c_master_recv(ptn_bridge->client, buf, len);
if (ret <= 0) {
DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
return ret;
}
return 0;
}
static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
char val)
{
int ret;
char buf[2];
buf[0] = addr;
buf[1] = val;
ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
if (ret <= 0) {
DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
return ret;
}
return 0;
}
static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
{
int ret;
char val;
/* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
ptn_bridge->edid_emulation);
if (ret) {
DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);
return ret;
}
/* Enable EDID emulation and select the desired EDID */
val = 1 << PTN3460_EDID_ENABLE_EMULATION |
ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;
ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
if (ret) {
DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);
return ret;
}
return 0;
}
static void ptn3460_pre_enable(struct drm_bridge *bridge)
{
struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
int ret;
if (ptn_bridge->enabled)
return;
gpiod_set_value(ptn_bridge->gpio_pd_n, 1);
gpiod_set_value(ptn_bridge->gpio_rst_n, 0);
usleep_range(10, 20);
gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
/*
* There's a bug in the PTN chip where it falsely asserts hotplug before
* it is fully functional. We're forced to wait for the maximum start up
* time specified in the chip's datasheet to make sure we're really up.
*/
msleep(90);
ret = ptn3460_select_edid(ptn_bridge);
if (ret)
DRM_ERROR("Select EDID failed ret=%d\n", ret);
ptn_bridge->enabled = true;
}
static void ptn3460_disable(struct drm_bridge *bridge)
{
struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
if (!ptn_bridge->enabled)
return;
ptn_bridge->enabled = false;
gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
}
static struct edid *ptn3460_get_edid(struct drm_bridge *bridge,
struct drm_connector *connector)
{
struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
bool power_off;
u8 *edid;
int ret;
power_off = !ptn_bridge->enabled;
ptn3460_pre_enable(&ptn_bridge->bridge);
edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
if (!edid) {
DRM_ERROR("Failed to allocate EDID\n");
goto out;
}
ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
EDID_LENGTH);
if (ret) {
kfree(edid);
edid = NULL;
goto out;
}
out:
if (power_off)
ptn3460_disable(&ptn_bridge->bridge);
return (struct edid *)edid;
}
static int ptn3460_connector_get_modes(struct drm_connector *connector)
{
struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector);
struct edid *edid;
int num_modes;
edid = ptn3460_get_edid(&ptn_bridge->bridge, connector);
drm_connector_update_edid_property(connector, edid);
num_modes = drm_add_edid_modes(connector, edid);
kfree(edid);
return num_modes;
}
static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
.get_modes = ptn3460_connector_get_modes,
};
static const struct drm_connector_funcs ptn3460_connector_funcs = {
.fill_modes = drm_helper_probe_single_connector_modes,
.destroy = drm_connector_cleanup,
.reset = drm_atomic_helper_connector_reset,
.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};
static int ptn3460_bridge_attach(struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags)
{
struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
int ret;
/* Let this driver create connector if requested */
ret = drm_bridge_attach(bridge->encoder, ptn_bridge->panel_bridge,
bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
if (ret < 0)
return ret;
if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
return 0;
if (!bridge->encoder) {
DRM_ERROR("Parent encoder object not found");
return -ENODEV;
}
ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
&ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
if (ret) {
DRM_ERROR("Failed to initialize connector with drm\n");
return ret;
}
drm_connector_helper_add(&ptn_bridge->connector,
&ptn3460_connector_helper_funcs);
drm_connector_register(&ptn_bridge->connector);
drm_connector_attach_encoder(&ptn_bridge->connector,
bridge->encoder);
drm_helper_hpd_irq_event(ptn_bridge->connector.dev);
return ret;
}
static const struct drm_bridge_funcs ptn3460_bridge_funcs = {
.pre_enable = ptn3460_pre_enable,
.disable = ptn3460_disable,
.attach = ptn3460_bridge_attach,
.get_edid = ptn3460_get_edid,
};
static int ptn3460_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct ptn3460_bridge *ptn_bridge;
struct drm_bridge *panel_bridge;
int ret;
ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
if (!ptn_bridge) {
return -ENOMEM;
}
panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
if (IS_ERR(panel_bridge))
return PTR_ERR(panel_bridge);
ptn_bridge->panel_bridge = panel_bridge;
ptn_bridge->client = client;
ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
GPIOD_OUT_HIGH);
if (IS_ERR(ptn_bridge->gpio_pd_n)) {
ret = PTR_ERR(ptn_bridge->gpio_pd_n);
dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
return ret;
}
/*
* Request the reset pin low to avoid the bridge being
* initialized prematurely
*/
ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(ptn_bridge->gpio_rst_n)) {
ret = PTR_ERR(ptn_bridge->gpio_rst_n);
DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
return ret;
}
ret = of_property_read_u32(dev->of_node, "edid-emulation",
&ptn_bridge->edid_emulation);
if (ret) {
dev_err(dev, "Can't read EDID emulation value\n");
return ret;
}
ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS;
ptn_bridge->bridge.of_node = dev->of_node;
drm_bridge_add(&ptn_bridge->bridge);
i2c_set_clientdata(client, ptn_bridge);
return 0;
}
static void ptn3460_remove(struct i2c_client *client)
{
struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);
drm_bridge_remove(&ptn_bridge->bridge);
}
static const struct i2c_device_id ptn3460_i2c_table[] = {
{"ptn3460", 0},
{},
};
MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);
static const struct of_device_id ptn3460_match[] = {
{ .compatible = "nxp,ptn3460" },
{},
};
MODULE_DEVICE_TABLE(of, ptn3460_match);
static struct i2c_driver ptn3460_driver = {
.id_table = ptn3460_i2c_table,
.probe = ptn3460_probe,
.remove = ptn3460_remove,
.driver = {
.name = "nxp,ptn3460",
.of_match_table = ptn3460_match,
},
};
module_i2c_driver(ptn3460_driver);
MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
MODULE_LICENSE("GPL v2");
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