From: Jonathan Selnes <jonathansb1@xxxxxxxxx> Support reading and writing the EDID EEPROM through the v4l2 API. Signed-off-by: Jonathan Selnes <jonathansb1@xxxxxxxxx> Co-developed-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Erling Ljunggren <hljunggr@xxxxxxxxx> --- MAINTAINERS | 7 + drivers/media/i2c/Kconfig | 9 + drivers/media/i2c/Makefile | 1 + drivers/media/i2c/cat24c208.c | 421 ++++++++++++++++++++++++++++++++++ 4 files changed, 438 insertions(+) create mode 100644 drivers/media/i2c/cat24c208.c diff --git a/MAINTAINERS b/MAINTAINERS index 7d9490a5c15a..407d76c42bab 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14912,6 +14912,13 @@ S: Maintained T: git git://linuxtv.org/media_tree.git F: drivers/media/i2c/ov9734.c +ON SEMICONDUCTOR CAT24C208 EDID EEPROM DRIVER +M: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> +L: linux-media@xxxxxxxxxxxxxxx +S: Maintained +F: Documentation/devicetree/bindings/media/i2c/onnn,cat24c208.yaml +F: drivers/media/i2c/cat24c208* + ONENAND FLASH DRIVER M: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> L: linux-mtd@xxxxxxxxxxxxxxxxxxx diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig index 2b20aa6c37b1..2f5f9f058b48 100644 --- a/drivers/media/i2c/Kconfig +++ b/drivers/media/i2c/Kconfig @@ -1530,6 +1530,15 @@ endmenu menu "Miscellaneous helper chips" visible if !MEDIA_HIDE_ANCILLARY_SUBDRV +config VIDEO_CAT24C208 + tristate "ON Semiconductor cat24c208 EDID EEPROM" + depends on VIDEO_DEV && I2C && OF + help + Support for the ON Semiconductor CAT24C208 Dual Port EDID EEPROM. + + To compile this driver as a module, choose M here: the + module will be called cat24c208. + config VIDEO_I2C tristate "I2C transport video support" depends on VIDEO_DEV && I2C diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile index 3e1696963e7f..70e4360a21ba 100644 --- a/drivers/media/i2c/Makefile +++ b/drivers/media/i2c/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_VIDEO_APTINA_PLL) += aptina-pll.o obj-$(CONFIG_VIDEO_BT819) += bt819.o obj-$(CONFIG_VIDEO_BT856) += bt856.o obj-$(CONFIG_VIDEO_BT866) += bt866.o +obj-$(CONFIG_VIDEO_CAT24C208) += cat24c208.o obj-$(CONFIG_VIDEO_CCS) += ccs/ obj-$(CONFIG_VIDEO_CCS_PLL) += ccs-pll.o obj-$(CONFIG_VIDEO_CS3308) += cs3308.o diff --git a/drivers/media/i2c/cat24c208.c b/drivers/media/i2c/cat24c208.c new file mode 100644 index 000000000000..9e4e146cdeff --- /dev/null +++ b/drivers/media/i2c/cat24c208.c @@ -0,0 +1,421 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * HDMI i2c controlled EEPROM from ON Semiconductor or Catalyst Semiconductor + * + * Support for i2c based DDC EEPROM + * + * Copyright (C) 2021-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + */ + +/* + * REF_01 - ON Semiconductor, cat24c208, Datasheet, URL : https://www.onsemi.com/pdf/datasheet/cat24c208-d.pdf + * Revision 7, May 2018 + */ + +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/mod_devicetable.h> +#include <linux/slab.h> +#include <linux/videodev2.h> + +#include <media/v4l2-device.h> +#include <media/v4l2-fh.h> +#include <media/v4l2-ioctl.h> + +MODULE_DESCRIPTION("cat24c208 EDID EEPROM driver"); +MODULE_AUTHOR("Jonathan Selnes Bognaes <jonathansb1@xxxxxxxxx>"); +MODULE_LICENSE("GPL"); + +/* + * CAT24C208 setup + */ +#define BYTES_PER_BLOCK 128 +#define EDID_OFFSET_EXT_FLAG 126 +#define MAX_WRITE_BYTES 16 +#define NUM_BLOCKS 4 +#define NUM_CLIENTS 3 +#define CONFIG_NB_BIT BIT(0) +#define CONFIG_AB0_BIT BIT(1) +#define CONFIG_AB1_BIT BIT(2) +#define CONFIG_WE_BIT BIT(3) + +/* + * From the datasheet: REF_01 + * + * The write cycle time is the time from a valid stop condition of a write + * sequence to the end of the internal program/erase cycle. During the write + * cycle, the bus interface circuits are disabled, SDA is allowed to remain + * high, and the device does not respond to its slave address. + */ +#define WRITE_CYCLE_TIME_US 5000 + +/* + * CAT24C208 addresses + */ +#define CONFIG_I2C_ADDR 0x31 +#define EEPROM_I2C_ADDR 0x50 +#define SEGMENT_I2C_ADDR 0x30 + +struct cat24c208_state { + struct i2c_client *dev_client; + struct i2c_client *data_client; + struct i2c_client *seg_client; + // V4L2 ioctl serialization + struct mutex lock; + + struct v4l2_device v4l2_dev; + struct video_device vdev; + + u8 edid_blocks; // edid length can vary, one block = 128 bytes + u8 edid[BYTES_PER_BLOCK * NUM_BLOCKS]; // actual active edid data +}; + +static const struct v4l2_file_operations cat24c208_fops = { + .owner = THIS_MODULE, + .open = v4l2_fh_open, + .release = v4l2_fh_release, + .unlocked_ioctl = video_ioctl2, +}; + +static int cat24c208_seg_write(struct cat24c208_state *state, u8 *data, u16 len, u8 seg) +{ + struct i2c_msg msg[] = { + { + .addr = state->seg_client->addr, // Segment + .buf = &seg, + .len = 1, + .flags = 0, + }, + { + .addr = state->data_client->addr, // write data + .buf = data, + .len = len, + .flags = 0, + }, + }; + int err; + + if (seg) + err = i2c_transfer(state->dev_client->adapter, msg, ARRAY_SIZE(msg)); + else + err = i2c_transfer(state->dev_client->adapter, &msg[1], 1); + + if (err < 0) + dev_err(&state->dev_client->dev, "Writing to 0x%x failed (segment %d)\n", + state->data_client->addr, seg); + + usleep_range(WRITE_CYCLE_TIME_US, 2 * WRITE_CYCLE_TIME_US); + return err < 0 ? err : 0; +} + +static int cat24c208_edid_read(struct cat24c208_state *state, u8 *data, u8 seg, u8 offset, u16 len) +{ + int err; + + len *= BYTES_PER_BLOCK; + if (seg) { + struct i2c_msg msg[] = { + { + .addr = state->seg_client->addr, // Segment + .buf = &seg, + .len = 1, + .flags = 0, + }, + { + .addr = state->data_client->addr, // read data + .buf = data, + .len = len, + .flags = I2C_M_RD, + }, + }; + err = i2c_transfer(state->dev_client->adapter, msg, ARRAY_SIZE(msg)); + } else { + struct i2c_msg msg[] = { + { + .addr = state->data_client->addr, // set offset + .buf = &offset, + .len = 1, + .flags = 0, + }, + { + .addr = state->data_client->addr, // read data + .buf = data, + .len = len, + .flags = I2C_M_RD, + }, + }; + err = i2c_transfer(state->dev_client->adapter, msg, ARRAY_SIZE(msg)); + } + + if (err < 0) + dev_err(&state->dev_client->dev, "Reading of EDID failed\n"); + return err < 0 ? err : 0; +} + +static int cat24c208_set_config(struct i2c_client *client) +{ + u8 buf[2] = { 0, CONFIG_NB_BIT }; + struct i2c_msg msg = { + .addr = client->addr, + .buf = buf, + .len = sizeof(buf), + .flags = 0, + }; + int err; + + err = i2c_transfer(client->adapter, &msg, 1); + if (err < 0) + dev_err(&client->dev, "Could not set config register\n"); + + usleep_range(WRITE_CYCLE_TIME_US, 2 * WRITE_CYCLE_TIME_US); + return err < 0 ? err : 0; +} + +static bool cat24c208_is_valid_edid(const u8 *block) +{ + static const u8 header_pattern[] = { + 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 + }; + + return !memcmp(block, header_pattern, sizeof(header_pattern)); +} + +static int cat24c208_set_edid(struct file *file, void *fh, struct v4l2_edid *edid) +{ + struct cat24c208_state *state = video_drvdata(file); + u8 buf[MAX_WRITE_BYTES + 1]; + int err; + int seg; + int i; + + memset(edid->reserved, 0, sizeof(edid->reserved)); + + if (edid->pad) + return -EINVAL; + + if (edid->blocks > NUM_BLOCKS) { + edid->blocks = NUM_BLOCKS; + return -E2BIG; + } + + if (edid->start_block) + return -EINVAL; + + state->edid_blocks = edid->blocks; + memcpy(state->edid, edid->edid, state->edid_blocks * BYTES_PER_BLOCK); + + /* Write EDID to EEPROM */ + for (i = 0; i < edid->blocks * BYTES_PER_BLOCK; i = i + MAX_WRITE_BYTES) { + if (i >= 2 * BYTES_PER_BLOCK) { + seg = 1; + buf[0] = i - BYTES_PER_BLOCK * 2; + } else { + seg = 0; + buf[0] = i; + } + + memcpy(buf + 1, &edid->edid[i], MAX_WRITE_BYTES); + err = cat24c208_seg_write(state, buf, MAX_WRITE_BYTES + 1, seg); + if (err) { + dev_err(&state->dev_client->dev, + "Could not write EDID to EEPROM, i: %d\n", i); + return err; + } + } + + return 0; +} + +static int cat24c208_get_edid(struct file *file, void *fh, struct v4l2_edid *edid) +{ + struct cat24c208_state *state = video_drvdata(file); + + memset(edid->reserved, 0, sizeof(edid->reserved)); + + if (edid->pad != 0) + return -EINVAL; + + if (edid->start_block == 0 && edid->blocks == 0) { + edid->blocks = state->edid_blocks; + return 0; + } + + if (state->edid_blocks == 0) + return -ENODATA; + + if (edid->start_block >= state->edid_blocks) + return -EINVAL; + + if (edid->start_block + edid->blocks > state->edid_blocks) + edid->blocks = state->edid_blocks - edid->start_block; + + memcpy(edid->edid, state->edid + edid->start_block * BYTES_PER_BLOCK, + edid->blocks * BYTES_PER_BLOCK); + + return 0; +} + +static int cat24c208_get_input(struct file *file, void *priv, unsigned int *i) +{ + *i = 0; + return 0; +} + +static int cat24c208_set_input(struct file *file, void *priv, unsigned int i) +{ + return i > 0 ? -EINVAL : 0; +} + +static int cat24c208_enum_input(struct file *file, void *priv, + struct v4l2_input *inp) +{ + if (inp->index) + return -EINVAL; + strscpy(inp->name, "HDMI", sizeof(inp->name)); + inp->capabilities = 0; + inp->type = V4L2_INPUT_TYPE_CAMERA; + return 0; +} + +static int cat24c208_querycap(struct file *file, + void *priv, struct v4l2_capability *cap) +{ + struct cat24c208_state *state = video_drvdata(file); + struct i2c_client *client = state->dev_client; + + strscpy(cap->driver, "cat24c208", sizeof(cap->driver)); + strscpy(cap->card, "cat24c208 EDID EEPROM", sizeof(cap->card)); + snprintf(cap->bus_info, sizeof(cap->bus_info), + "I2C:%d-%04x", client->adapter->nr, client->addr); + return 0; +} + +static const struct v4l2_ioctl_ops cat24c208_ioctl_ops = { + .vidioc_querycap = cat24c208_querycap, + .vidioc_g_edid = cat24c208_get_edid, + .vidioc_s_edid = cat24c208_set_edid, + .vidioc_g_input = cat24c208_get_input, + .vidioc_s_input = cat24c208_set_input, + .vidioc_enum_input = cat24c208_enum_input, +}; + +static void cat24c208_release(struct video_device *vdev) +{ + struct cat24c208_state *state = video_get_drvdata(vdev); + + v4l2_device_unregister(&state->v4l2_dev); + mutex_destroy(&state->lock); + kfree(state); +} + +static int cat24c208_probe(struct i2c_client *client) +{ + struct cat24c208_state *state; + struct v4l2_device *v4l2_dev; + int blocks; + int ret; + + state = kzalloc(sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + state->dev_client = client; + state->data_client = i2c_new_ancillary_device(client, "eeprom", EEPROM_I2C_ADDR); + if (IS_ERR(state->data_client)) { + ret = PTR_ERR(state->data_client); + goto free_state; + } + state->seg_client = i2c_new_ancillary_device(client, "segment", SEGMENT_I2C_ADDR); + if (IS_ERR(state->seg_client)) { + ret = PTR_ERR(state->seg_client); + goto unreg_i2c_first; + } + + ret = cat24c208_set_config(client); + if (ret) + goto unreg_i2c_all; + + if (cat24c208_edid_read(state, state->edid, 0, 0, 2) >= 0 && + cat24c208_is_valid_edid(state->edid)) { + unsigned int i; + + blocks = 1 + state->edid[EDID_OFFSET_EXT_FLAG]; + state->edid_blocks = blocks; + for (i = 2; i < blocks; i += 2) { + if (cat24c208_edid_read(state, state->edid + i * BYTES_PER_BLOCK, + i / 2, 0, (i + 1 >= blocks ? 1 : 2))) { + state->edid_blocks = i; + break; + } + } + } + + v4l2_dev = &state->v4l2_dev; + strscpy(v4l2_dev->name, "cat24c208", sizeof(v4l2_dev->name)); + ret = v4l2_device_register(&client->dev, v4l2_dev); + if (ret) { + dev_err(&client->dev, "v4l2_device_register failed: %d\n", ret); + goto unreg_i2c_all; + } + + mutex_init(&state->lock); + + snprintf(state->vdev.name, sizeof(state->vdev.name), + "cat24c208 %d-%d", client->adapter->nr, client->addr); + + state->vdev.v4l2_dev = v4l2_dev; + state->vdev.fops = &cat24c208_fops; + state->vdev.ioctl_ops = &cat24c208_ioctl_ops; + state->vdev.lock = &state->lock; + state->vdev.release = cat24c208_release; + state->vdev.device_caps = V4L2_CAP_EDID_MEMORY; + + video_set_drvdata(&state->vdev, state); + i2c_set_clientdata(client, state); + ret = video_register_device(&state->vdev, VFL_TYPE_VIDEO, -1); + if (ret != 0) { + dev_err(&client->dev, "Video registering failed: %d\n", ret); + goto unreg_v4l2_dev; + } + return 0; + +unreg_v4l2_dev: + v4l2_device_unregister(&state->v4l2_dev); +unreg_i2c_all: + i2c_unregister_device(state->seg_client); +unreg_i2c_first: + i2c_unregister_device(state->data_client); +free_state: + kfree(state); + return ret; +} + +static int cat24c208_remove(struct i2c_client *client) +{ + struct cat24c208_state *state = i2c_get_clientdata(client); + + i2c_unregister_device(state->data_client); + i2c_unregister_device(state->seg_client); + video_unregister_device(&state->vdev); + + return 0; +} + +static const struct of_device_id cat24c208_of_match[] = { + { .compatible = "onnn,cat24c208"}, + {} +}; +MODULE_DEVICE_TABLE(of, cat24c208_of_match); + +static struct i2c_driver cat24c208_driver = { + .driver = { + .name = "cat24c208", + .of_match_table = cat24c208_of_match, + }, + .probe_new = cat24c208_probe, + .remove = cat24c208_remove, +}; +module_i2c_driver(cat24c208_driver); -- 2.37.1
