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Diffstat (limited to 'drivers/media/i2c/max9271.c')
-rw-r--r--drivers/media/i2c/max9271.c374
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/media/i2c/max9271.c b/drivers/media/i2c/max9271.c
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index 0000000000..ff86c8c4ea
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+++ b/drivers/media/i2c/max9271.c
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+// 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");