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path: root/drivers/gpu/drm/bridge/nxp-ptn3460.c
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Diffstat (limited to 'drivers/gpu/drm/bridge/nxp-ptn3460.c')
-rw-r--r--drivers/gpu/drm/bridge/nxp-ptn3460.c350
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");