1 files changed, 418 insertions, 0 deletions

diff --git a/drivers/gpu/drm/bridge/ptn3460.c b/drivers/gpu/drm/bridge/ptn3460.c
new file mode 100644
index 000000000..63a09e407
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ptn3460.c
@@ -0,0 +1,418 @@
+/*
+ * 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/gpio/consumer.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");