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Diffstat (limited to 'drivers/media/i2c/max9271.c')
| -rw-r--r-- | drivers/media/i2c/max9271.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/media/i2c/max9271.c b/drivers/media/i2c/max9271.c new file mode 100644 index 0000000000..ff86c8c4ea --- /dev/null +++ b/drivers/media/i2c/max9271.c @@ -0,0 +1,374 @@ +// 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"); |