Ported from chromeos-3.18.
Signed-off-by: Ulrich Hecht ulrich.hecht+renesas@gmail.com --- drivers/gpu/drm/bridge/Kconfig | 9 ++ drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/analogix-anx7688.c | 233 ++++++++++++++++++++++++++++++ 3 files changed, 243 insertions(+) create mode 100644 drivers/gpu/drm/bridge/analogix-anx7688.c
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index a1c0d95..712ac0a 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -38,6 +38,15 @@ config DRM_PARADE_PS8640 The PS8640 is a high-performance and low-power MIPI DSI to eDP converter
+config DRM_ANALOGIX_ANX7688 + tristate "Analogix ANX7688 bridge" + depends on DRM + select DRM_KMS_HELPER + ---help--- + ANX7688 is a transmitter to support DisplayPort over USB-C for + smartphone and tablets. + This driver only supports the HDMI to DP component of the chip. + config DRM_ANALOGIX_ANX78XX tristate "Analogix ANX78XX bridge" select DRM_KMS_HELPER diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index 6be8a9d..9cbf788 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -1,6 +1,7 @@ ccflags-y := -Iinclude/drm
obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o +obj-$(CONFIG_DRM_ANALOGIX_ANX7688) += analogix-anx7688.o obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o obj-$(CONFIG_DRM_GENERIC_GPIO_MUX) += generic-gpio-mux.o obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o diff --git a/drivers/gpu/drm/bridge/analogix-anx7688.c b/drivers/gpu/drm/bridge/analogix-anx7688.c new file mode 100644 index 0000000..cc995c8 --- /dev/null +++ b/drivers/gpu/drm/bridge/analogix-anx7688.c @@ -0,0 +1,233 @@ +/* + * ANX7688 HDMI->DP bridge driver + * + * Copyright (C) 2016 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/i2c.h> +#include <linux/module.h> +#include <drm/drm_crtc.h> + +/* Register addresses */ +#define VENDOR_ID_REG 0x00 +#define DEVICE_ID_REG 0x02 + +#define FW_VERSION_REG 0x80 + +#define DP_BANDWIDTH_REG 0x85 +#define DP_LANE_COUNT_REG 0x86 + +#define VENDOR_ID 0x1f29 +#define DEVICE_ID 0x7688 + +/* First supported firmware version (0.85) */ +#define MINIMUM_FW_VERSION 0x0085 + +struct anx7688 { + struct drm_bridge bridge; + struct i2c_client *client; + + bool filter; +}; + +static int anx7688_read(struct i2c_client *client, u8 reg, u8 *data, + u16 data_len) +{ + int ret; + struct i2c_msg msgs[] = { + { + .addr = client->addr, + .flags = 0, + .len = 1, + .buf = ®, + }, + { + .addr = client->addr, + .flags = I2C_M_RD, + .len = data_len, + .buf = data, + } + }; + + ret = i2c_transfer(client->adapter, msgs, 2); + + if (ret == 2) + return 0; + if (ret < 0) + return ret; + else + return -EIO; +} + +static inline struct anx7688 *bridge_to_anx7688(struct drm_bridge *bridge) +{ + return container_of(bridge, struct anx7688, bridge); +} + +static bool anx7688_bridge_mode_fixup(struct drm_bridge *bridge, + const struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode) +{ + struct anx7688 *anx7688 = bridge_to_anx7688(bridge); + u8 regs[2]; + u8 dpbw, lanecount; + int totalbw, requiredbw; + int ret; + + if (!anx7688->filter) + return true; + + /* Read both regs 0x85 (bandwidth) and 0x86 (lane count). */ + ret = anx7688_read(anx7688->client, DP_BANDWIDTH_REG, regs, 2); + if (ret < 0) { + dev_err(&anx7688->client->dev, + "Failed to read bandwidth/lane count\n"); + return false; + } + dpbw = regs[0]; + lanecount = regs[1]; + + /* Maximum 0x19 bandwidth (6.75 Gbps Turbo mode), 2 lanes */ + if (dpbw > 0x19 || lanecount > 2) { + dev_err(&anx7688->client->dev, + "Invalid bandwidth/lane count (%02x/%d)\n", + dpbw, lanecount); + return false; + } + + /* Compute available bandwidth (kHz) */ + totalbw = dpbw * lanecount * 270000 * 8 / 10; + + /* Required bandwidth (8 bpc, kHz) */ + requiredbw = mode->clock * 8 * 3; + + dev_dbg(&anx7688->client->dev, + "DP bandwidth: %d kHz (%02x/%d); mode requires %d Khz\n", + totalbw, dpbw, lanecount, requiredbw); + + if (totalbw == 0) { + dev_warn(&anx7688->client->dev, + "Bandwidth/lane count are 0, not rejecting modes\n"); + return true; + } + + return totalbw >= requiredbw; +} + +static const struct drm_bridge_funcs anx7688_bridge_funcs = { + .mode_fixup = anx7688_bridge_mode_fixup, +}; + +static int anx7688_i2c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct anx7688 *anx7688; + int ret; + u8 buffer[4]; + u16 vendor, device, fwversion; + + anx7688 = devm_kzalloc(&client->dev, sizeof(*anx7688), GFP_KERNEL); + if (!anx7688) + return -ENOMEM; + +#if IS_ENABLED(CONFIG_OF) + anx7688->bridge.of_node = client->dev.of_node; +#endif + + anx7688->client = client; + i2c_set_clientdata(client, anx7688); + + /* Read both vendor and device id (4 bytes). */ + ret = anx7688_read(client, VENDOR_ID_REG, buffer, 4); + if (ret) { + dev_err(&client->dev, "Failed to read chip vendor/device id\n"); + return ret; + } + + vendor = (u16)buffer[1] << 8 | buffer[0]; + device = (u16)buffer[3] << 8 | buffer[2]; + if (vendor != VENDOR_ID || device != DEVICE_ID) { + dev_err(&client->dev, + "Invalid vendor/device id %04x/%04x\n", + vendor, device); + return -ENODEV; + } + + ret = anx7688_read(client, FW_VERSION_REG, buffer, 2); + if (ret) { + dev_err(&client->dev, "Failed to read firmware version\n"); + return ret; + } + + fwversion = (u16)buffer[0] << 8 | buffer[1]; + dev_info(&client->dev, "ANX7688 firwmare version %02x.%02x\n", + buffer[0], buffer[1]); + + /* FW version >= 0.85 supports bandwidth/lane count registers */ + if (fwversion >= MINIMUM_FW_VERSION) { + anx7688->filter = true; + } else { + /* Warn, but not fail, for backwards compatibility. */ + dev_warn(&client->dev, + "Old ANX7688 FW version (%02x.%02x), not filtering\n", + buffer[0], buffer[1]); + } + + anx7688->bridge.funcs = &anx7688_bridge_funcs; + ret = drm_bridge_add(&anx7688->bridge); + if (ret < 0) { + dev_err(&client->dev, "Failed to add drm bridge\n"); + return ret; + } + + return 0; +} + +static int anx7688_i2c_remove(struct i2c_client *client) +{ + struct anx7688 *anx7688 = i2c_get_clientdata(client); + + drm_bridge_remove(&anx7688->bridge); + + return 0; +} + +static const struct i2c_device_id anx7688_id[] = { + { "anx7688", 0 }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(i2c, anx7688_id); + +#if IS_ENABLED(CONFIG_OF) +static const struct of_device_id anx7688_match_table[] = { + { .compatible = "analogix,anx7688", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, anx7688_match_table); +#endif + +static struct i2c_driver anx7688_driver = { + .driver = { + .name = "anx7688", + .of_match_table = of_match_ptr(anx7688_match_table), + }, + .probe = anx7688_i2c_probe, + .remove = anx7688_i2c_remove, + .id_table = anx7688_id, +}; + +module_i2c_driver(anx7688_driver); + +MODULE_DESCRIPTION("ANX7688 SlimPort Transmitter driver"); +MODULE_AUTHOR("Nicolas Boichat drinkcat@chromium.org"); +MODULE_LICENSE("GPL v2");