diff options
Diffstat (limited to 'drivers/gpu/drm/bridge/nxp-ptn3460.c')
| -rw-r--r-- | drivers/gpu/drm/bridge/nxp-ptn3460.c | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/nxp-ptn3460.c b/drivers/gpu/drm/bridge/nxp-ptn3460.c new file mode 100644 index 000000000..8686b20ac --- /dev/null +++ b/drivers/gpu/drm/bridge/nxp-ptn3460.c @@ -0,0 +1,350 @@ +// 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, + const struct i2c_device_id *id) +{ + 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"); |