drm/bridge: Add PTN3460 bridge driver
This patch adds a drm_bridge driver for the PTN3460 DisplayPort to LVDS
bridge chip.
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
diff --git a/drivers/gpu/drm/bridge/ptn3460.c b/drivers/gpu/drm/bridge/ptn3460.c
new file mode 100644
index 0000000..a9e5c1a
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ptn3460.c
@@ -0,0 +1,349 @@
+/*
+ * 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/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+
+#include "drmP.h"
+#include "drm_edid.h"
+#include "drm_crtc.h"
+#include "drm_crtc_helper.h"
+
+#include "bridge/ptn3460.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_encoder *encoder;
+ struct drm_bridge *bridge;
+ struct edid *edid;
+ int gpio_pd_n;
+ int gpio_rst_n;
+ u32 edid_emulation;
+ bool enabled;
+};
+
+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->driver_private;
+ int ret;
+
+ if (ptn_bridge->enabled)
+ return;
+
+ if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+ gpio_set_value(ptn_bridge->gpio_pd_n, 1);
+
+ if (gpio_is_valid(ptn_bridge->gpio_rst_n)) {
+ gpio_set_value(ptn_bridge->gpio_rst_n, 0);
+ udelay(10);
+ gpio_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_enable(struct drm_bridge *bridge)
+{
+}
+
+static void ptn3460_disable(struct drm_bridge *bridge)
+{
+ struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+
+ if (!ptn_bridge->enabled)
+ return;
+
+ ptn_bridge->enabled = false;
+
+ if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+ gpio_set_value(ptn_bridge->gpio_rst_n, 1);
+
+ if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+ gpio_set_value(ptn_bridge->gpio_pd_n, 0);
+}
+
+static void ptn3460_post_disable(struct drm_bridge *bridge)
+{
+}
+
+void ptn3460_bridge_destroy(struct drm_bridge *bridge)
+{
+ struct ptn3460_bridge *ptn_bridge = bridge->driver_private;
+
+ drm_bridge_cleanup(bridge);
+ if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+ gpio_free(ptn_bridge->gpio_pd_n);
+ if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+ gpio_free(ptn_bridge->gpio_rst_n);
+ /* Nothing else to free, we've got devm allocated memory */
+}
+
+struct drm_bridge_funcs ptn3460_bridge_funcs = {
+ .pre_enable = ptn3460_pre_enable,
+ .enable = ptn3460_enable,
+ .disable = ptn3460_disable,
+ .post_disable = ptn3460_post_disable,
+ .destroy = ptn3460_bridge_destroy,
+};
+
+int ptn3460_get_modes(struct drm_connector *connector)
+{
+ struct ptn3460_bridge *ptn_bridge;
+ u8 *edid;
+ int ret, num_modes;
+ bool power_off;
+
+ ptn_bridge = container_of(connector, struct ptn3460_bridge, 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);
+ num_modes = 0;
+ 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 int ptn3460_mode_valid(struct drm_connector *connector,
+ struct drm_display_mode *mode)
+{
+ return MODE_OK;
+}
+
+struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector)
+{
+ struct ptn3460_bridge *ptn_bridge;
+
+ ptn_bridge = container_of(connector, struct ptn3460_bridge, connector);
+
+ return ptn_bridge->encoder;
+}
+
+struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
+ .get_modes = ptn3460_get_modes,
+ .mode_valid = ptn3460_mode_valid,
+ .best_encoder = ptn3460_best_encoder,
+};
+
+enum drm_connector_status ptn3460_detect(struct drm_connector *connector,
+ bool force)
+{
+ return connector_status_connected;
+}
+
+void ptn3460_connector_destroy(struct drm_connector *connector)
+{
+ drm_connector_cleanup(connector);
+}
+
+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,
+};
+
+int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder,
+ struct i2c_client *client, struct device_node *node)
+{
+ int ret;
+ struct drm_bridge *bridge;
+ struct ptn3460_bridge *ptn_bridge;
+
+ bridge = devm_kzalloc(dev->dev, sizeof(*bridge), GFP_KERNEL);
+ if (!bridge) {
+ DRM_ERROR("Failed to allocate drm bridge\n");
+ return -ENOMEM;
+ }
+
+ ptn_bridge = devm_kzalloc(dev->dev, sizeof(*ptn_bridge), GFP_KERNEL);
+ if (!ptn_bridge) {
+ DRM_ERROR("Failed to allocate ptn bridge\n");
+ return -ENOMEM;
+ }
+
+ ptn_bridge->client = client;
+ ptn_bridge->encoder = encoder;
+ ptn_bridge->bridge = bridge;
+ ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0);
+ if (gpio_is_valid(ptn_bridge->gpio_pd_n)) {
+ ret = gpio_request_one(ptn_bridge->gpio_pd_n,
+ GPIOF_OUT_INIT_HIGH, "PTN3460_PD_N");
+ if (ret) {
+ DRM_ERROR("Request powerdown-gpio failed (%d)\n", ret);
+ return ret;
+ }
+ }
+
+ ptn_bridge->gpio_rst_n = of_get_named_gpio(node, "reset-gpio", 0);
+ if (gpio_is_valid(ptn_bridge->gpio_rst_n)) {
+ /*
+ * Request the reset pin low to avoid the bridge being
+ * initialized prematurely
+ */
+ ret = gpio_request_one(ptn_bridge->gpio_rst_n,
+ GPIOF_OUT_INIT_LOW, "PTN3460_RST_N");
+ if (ret) {
+ DRM_ERROR("Request reset-gpio failed (%d)\n", ret);
+ gpio_free(ptn_bridge->gpio_pd_n);
+ return ret;
+ }
+ }
+
+ ret = of_property_read_u32(node, "edid-emulation",
+ &ptn_bridge->edid_emulation);
+ if (ret) {
+ DRM_ERROR("Can't read edid emulation value\n");
+ goto err;
+ }
+
+ ret = drm_bridge_init(dev, bridge, &ptn3460_bridge_funcs);
+ if (ret) {
+ DRM_ERROR("Failed to initialize bridge with drm\n");
+ goto err;
+ }
+
+ bridge->driver_private = ptn_bridge;
+ encoder->bridge = bridge;
+
+ ret = drm_connector_init(dev, &ptn_bridge->connector,
+ &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
+ if (ret) {
+ DRM_ERROR("Failed to initialize connector with drm\n");
+ goto err;
+ }
+ drm_connector_helper_add(&ptn_bridge->connector,
+ &ptn3460_connector_helper_funcs);
+ drm_sysfs_connector_add(&ptn_bridge->connector);
+ drm_mode_connector_attach_encoder(&ptn_bridge->connector, encoder);
+
+ return 0;
+
+err:
+ if (gpio_is_valid(ptn_bridge->gpio_pd_n))
+ gpio_free(ptn_bridge->gpio_pd_n);
+ if (gpio_is_valid(ptn_bridge->gpio_rst_n))
+ gpio_free(ptn_bridge->gpio_rst_n);
+ return ret;
+}