diff options
Diffstat (limited to 'kernel/drivers/gpu/drm/bridge/ptn3460.c')
-rw-r--r-- | kernel/drivers/gpu/drm/bridge/ptn3460.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/kernel/drivers/gpu/drm/bridge/ptn3460.c b/kernel/drivers/gpu/drm/bridge/ptn3460.c new file mode 100644 index 000000000..9d2f05338 --- /dev/null +++ b/kernel/drivers/gpu/drm/bridge/ptn3460.c @@ -0,0 +1,417 @@ +/* + * NXP PTN3460 DP/LVDS bridge driver + * + * Copyright (C) 2013 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/delay.h> +#include <linux/gpio.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_gpio.h> +#include <linux/of_graph.h> + +#include <drm/drm_panel.h> + +#include "bridge/ptn3460.h" + +#include "drm_crtc.h" +#include "drm_crtc_helper.h" +#include "drm_edid.h" +#include "drmP.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 edid *edid; + struct drm_panel *panel; + 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); + + if (drm_panel_prepare(ptn_bridge->panel)) { + DRM_ERROR("failed to prepare panel\n"); + return; + } + + /* + * 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_enable(struct drm_bridge *bridge) +{ + struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); + + if (drm_panel_enable(ptn_bridge->panel)) { + DRM_ERROR("failed to enable panel\n"); + return; + } +} + +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; + + if (drm_panel_disable(ptn_bridge->panel)) { + DRM_ERROR("failed to disable panel\n"); + return; + } + + gpiod_set_value(ptn_bridge->gpio_rst_n, 1); + gpiod_set_value(ptn_bridge->gpio_pd_n, 0); +} + +static void ptn3460_post_disable(struct drm_bridge *bridge) +{ + struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); + + if (drm_panel_unprepare(ptn_bridge->panel)) { + DRM_ERROR("failed to unprepare panel\n"); + return; + } +} + +static int ptn3460_get_modes(struct drm_connector *connector) +{ + struct ptn3460_bridge *ptn_bridge; + u8 *edid; + int ret, num_modes = 0; + bool power_off; + + ptn_bridge = connector_to_ptn3460(connector); + + if (ptn_bridge->edid) + return drm_add_edid_modes(connector, ptn_bridge->edid); + + 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"); + return 0; + } + + ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, + EDID_LENGTH); + if (ret) { + kfree(edid); + goto out; + } + + ptn_bridge->edid = (struct edid *)edid; + drm_mode_connector_update_edid_property(connector, ptn_bridge->edid); + + num_modes = drm_add_edid_modes(connector, ptn_bridge->edid); + +out: + if (power_off) + ptn3460_disable(&ptn_bridge->bridge); + + return num_modes; +} + +static struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector) +{ + struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector); + + return ptn_bridge->bridge.encoder; +} + +static struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { + .get_modes = ptn3460_get_modes, + .best_encoder = ptn3460_best_encoder, +}; + +static enum drm_connector_status ptn3460_detect(struct drm_connector *connector, + bool force) +{ + return connector_status_connected; +} + +static void ptn3460_connector_destroy(struct drm_connector *connector) +{ + drm_connector_cleanup(connector); +} + +static struct drm_connector_funcs ptn3460_connector_funcs = { + .dpms = drm_helper_connector_dpms, + .fill_modes = drm_helper_probe_single_connector_modes, + .detect = ptn3460_detect, + .destroy = ptn3460_connector_destroy, +}; + +static int ptn3460_bridge_attach(struct drm_bridge *bridge) +{ + struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge); + int ret; + + 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_mode_connector_attach_encoder(&ptn_bridge->connector, + bridge->encoder); + + if (ptn_bridge->panel) + drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector); + + drm_helper_hpd_irq_event(ptn_bridge->connector.dev); + + return ret; +} + +static struct drm_bridge_funcs ptn3460_bridge_funcs = { + .pre_enable = ptn3460_pre_enable, + .enable = ptn3460_enable, + .disable = ptn3460_disable, + .post_disable = ptn3460_post_disable, + .attach = ptn3460_bridge_attach, +}; + +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 device_node *endpoint, *panel_node; + int ret; + + ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); + if (!ptn_bridge) { + return -ENOMEM; + } + + endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); + if (endpoint) { + panel_node = of_graph_get_remote_port_parent(endpoint); + if (panel_node) { + ptn_bridge->panel = of_drm_find_panel(panel_node); + of_node_put(panel_node); + if (!ptn_bridge->panel) + return -EPROBE_DEFER; + } + } + + ptn_bridge->client = client; + + ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown"); + 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; + } + + ret = gpiod_direction_output(ptn_bridge->gpio_pd_n, 1); + if (ret) { + DRM_ERROR("cannot configure gpio_pd_n\n"); + return ret; + } + + ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset"); + 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; + } + /* + * Request the reset pin low to avoid the bridge being + * initialized prematurely + */ + ret = gpiod_direction_output(ptn_bridge->gpio_rst_n, 0); + if (ret) { + DRM_ERROR("cannot configure gpio_rst_n\n"); + 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.of_node = dev->of_node; + ret = drm_bridge_add(&ptn_bridge->bridge); + if (ret) { + DRM_ERROR("Failed to add bridge\n"); + return ret; + } + + i2c_set_clientdata(client, ptn_bridge); + + return 0; +} + +static int ptn3460_remove(struct i2c_client *client) +{ + struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client); + + drm_bridge_remove(&ptn_bridge->bridge); + + return 0; +} + +static const struct i2c_device_id ptn3460_i2c_table[] = { + {"nxp,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", + .owner = THIS_MODULE, + .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"); |