// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017-2020 Jacopo Mondi
* Copyright (C) 2017-2020 Kieran Bingham
* Copyright (C) 2017-2020 Laurent Pinchart
* Copyright (C) 2017-2020 Niklas Söderlund
* Copyright (C) 2016 Renesas Electronics Corporation
* Copyright (C) 2015 Cogent Embedded, Inc.
*
* This file exports functions to control the Maxim MAX9271 GMSL serializer
* chip. This is not a self-contained driver, as MAX9271 is usually embedded in
* camera modules with at least one image sensor and optional additional
* components, such as uController units or ISPs/DSPs.
*
* Drivers for the camera modules (i.e. rdacm20/21) are expected to use
* functions exported from this library driver to maximize code re-use.
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include "max9271.h"
static int max9271_read(struct max9271_device *dev, u8 reg)
{
int ret;
dev_dbg(&dev->client->dev, "%s(0x%02x)\n", __func__, reg);
ret = i2c_smbus_read_byte_data(dev->client, reg);
if (ret < 0)
dev_dbg(&dev->client->dev,
"%s: register 0x%02x read failed (%d)\n",
__func__, reg, ret);
return ret;
}
static int max9271_write(struct max9271_device *dev, u8 reg, u8 val)
{
int ret;
dev_dbg(&dev->client->dev, "%s(0x%02x, 0x%02x)\n", __func__, reg, val);
ret = i2c_smbus_write_byte_data(dev->client, reg, val);
if (ret < 0)
dev_err(&dev->client->dev,
"%s: register 0x%02x write failed (%d)\n",
__func__, reg, ret);
return ret;
}
/*
* max9271_pclk_detect() - Detect valid pixel clock from image sensor
*
* Wait up to 10ms for a valid pixel clock.
*
* Returns 0 for success, < 0 for pixel clock not properly detected
*/
static int max9271_pclk_detect(struct max9271_device *dev)
{
unsigned int i;
int ret;
for (i = 0; i < 100; i++) {
ret = max9271_read(dev, 0x15);
if (ret < 0)
return ret;
if (ret & MAX9271_PCLKDET)
return 0;
usleep_range(50, 100);
}
dev_err(&dev->client->dev, "Unable to detect valid pixel clock\n");
return -EIO;
}
void max9271_wake_up(struct max9271_device *dev)
{
/*
* Use the chip default address as this function has to be called
* before any other one.
*/
dev->client->addr = MAX9271_DEFAULT_ADDR;
i2c_smbus_read_byte(dev->client);
usleep_range(5000, 8000);
}
EXPORT_SYMBOL_GPL(max9271_wake_up);
int max9271_set_serial_link(struct max9271_device *dev, bool enable)
{
int ret;
u8 val = MAX9271_REVCCEN | MAX9271_FWDCCEN;
if (enable) {
ret = max9271_pclk_detect(dev);
if (ret)
return ret;
val |= MAX9271_SEREN;
} else {
val |= MAX9271_CLINKEN;
}
/*
* The serializer temporarily disables the reverse control channel for
* 350µs after starting/stopping the forward serial link, but the
* deserializer synchronization time isn't clearly documented.
*
* According to the serializer datasheet we should wait 3ms, while
* according to the deserializer datasheet we should wait 5ms.
*
* Short delays here appear to show bit-errors in the writes following.
* Therefore a conservative delay seems best here.
*/
ret = max9271_write(dev, 0x04, val);
if (ret < 0)
return ret;
usleep_range(5000, 8000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_set_serial_link);
int max9271_configure_i2c(struct max9271_device *dev, u8 i2c_config)
{
int ret;
ret = max9271_write(dev, 0x0d, i2c_config);
if (ret < 0)
return ret;
/* The delay required after an I2C bus configuration change is not
* characterized in the serializer manual. Sleep up to 5msec to
* stay safe.
*/
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_configure_i2c);
int max9271_set_high_threshold(struct max9271_device *dev, bool enable)
{
int ret;
ret = max9271_read(dev, 0x08);
if (ret < 0)
return ret;
/*
* Enable or disable reverse channel high threshold to increase
* immunity to power supply noise.
*/
ret = max9271_write(dev, 0x08, enable ? ret | BIT(0) : ret & ~BIT(0));
if (ret < 0)
return ret;
usleep_range(2000, 2500);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_set_high_threshold);
int max9271_configure_gmsl_link(struct max9271_device *dev)
{
int ret;
/*
* Configure the GMSL link:
*
* - Double input mode, high data rate, 24-bit mode
* - Latch input data on PCLKIN rising edge
* - Enable HS/VS encoding
* - 1-bit parity error detection
*
* TODO: Make the GMSL link configuration parametric.
*/
ret = max9271_write(dev, 0x07, MAX9271_DBL | MAX9271_HVEN |
MAX9271_EDC_1BIT_PARITY);
if (ret < 0)
return ret;
usleep_range(5000, 8000);
/*
* Adjust spread spectrum to +4% and auto-detect pixel clock
* and serial link rate.
*/
ret = max9271_write(dev, 0x02,
MAX9271_SPREAD_SPECT_4 | MAX9271_R02_RES |
MAX9271_PCLK_AUTODETECT |
MAX9271_SERIAL_AUTODETECT);
if (ret < 0)
return ret;
usleep_range(5000, 8000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_configure_gmsl_link);
int max9271_set_gpios(struct max9271_device *dev, u8 gpio_mask)
{
int ret;
ret = max9271_read(dev, 0x0f);
if (ret < 0)
return 0;
ret |= gpio_mask;
ret = max9271_write(dev, 0x0f, ret);
if (ret < 0) {
dev_err(&dev->client->dev, "Failed to set gpio (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_set_gpios);
int max9271_clear_gpios(struct max9271_device *dev, u8 gpio_mask)
{
int ret;
ret = max9271_read(dev, 0x0f);
if (ret < 0)
return 0;
ret &= ~gpio_mask;
ret = max9271_write(dev, 0x0f, ret);
if (ret < 0) {
dev_err(&dev->client->dev, "Failed to clear gpio (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_clear_gpios);
int max9271_enable_gpios(struct max9271_device *dev, u8 gpio_mask)
{
int ret;
ret = max9271_read(dev, 0x0e);
if (ret < 0)
return 0;
/* BIT(0) reserved: GPO is always enabled. */
ret |= (gpio_mask & ~BIT(0));
ret = max9271_write(dev, 0x0e, ret);
if (ret < 0) {
dev_err(&dev->client->dev, "Failed to enable gpio (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_enable_gpios);
int max9271_disable_gpios(struct max9271_device *dev, u8 gpio_mask)
{
int ret;
ret = max9271_read(dev, 0x0e);
if (ret < 0)
return 0;
/* BIT(0) reserved: GPO cannot be disabled */
ret &= ~(gpio_mask | BIT(0));
ret = max9271_write(dev, 0x0e, ret);
if (ret < 0) {
dev_err(&dev->client->dev, "Failed to disable gpio (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_disable_gpios);
int max9271_verify_id(struct max9271_device *dev)
{
int ret;
ret = max9271_read(dev, 0x1e);
if (ret < 0) {
dev_err(&dev->client->dev, "MAX9271 ID read failed (%d)\n",
ret);
return ret;
}
if (ret != MAX9271_ID) {
dev_err(&dev->client->dev, "MAX9271 ID mismatch (0x%02x)\n",
ret);
return -ENXIO;
}
return 0;
}
EXPORT_SYMBOL_GPL(max9271_verify_id);
int max9271_set_address(struct max9271_device *dev, u8 addr)
{
int ret;
ret = max9271_write(dev, 0x00, addr << 1);
if (ret < 0) {
dev_err(&dev->client->dev,
"MAX9271 I2C address change failed (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_set_address);
int max9271_set_deserializer_address(struct max9271_device *dev, u8 addr)
{
int ret;
ret = max9271_write(dev, 0x01, addr << 1);
if (ret < 0) {
dev_err(&dev->client->dev,
"MAX9271 deserializer address set failed (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_set_deserializer_address);
int max9271_set_translation(struct max9271_device *dev, u8 source, u8 dest)
{
int ret;
ret = max9271_write(dev, 0x09, source << 1);
if (ret < 0) {
dev_err(&dev->client->dev,
"MAX9271 I2C translation setup failed (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
ret = max9271_write(dev, 0x0a, dest << 1);
if (ret < 0) {
dev_err(&dev->client->dev,
"MAX9271 I2C translation setup failed (%d)\n", ret);
return ret;
}
usleep_range(3500, 5000);
return 0;
}
EXPORT_SYMBOL_GPL(max9271_set_translation);
MODULE_DESCRIPTION("Maxim MAX9271 GMSL Serializer");
MODULE_AUTHOR("Jacopo Mondi");
MODULE_LICENSE("GPL v2");
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