// SPDX-License-Identifier: GPL-2.0
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#define USE_HW_I2C
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#ifdef USE_HW_I2C
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#include "ddk750_chip.h"
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#include "ddk750_reg.h"
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#include "ddk750_hwi2c.h"
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#include "ddk750_power.h"
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#define MAX_HWI2C_FIFO 16
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#define HWI2C_WAIT_TIMEOUT 0xF0000
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int sm750_hw_i2c_init(unsigned char bus_speed_mode)
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{
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unsigned int value;
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/* Enable GPIO 30 & 31 as IIC clock & data */
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value = peek32(GPIO_MUX);
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value |= (GPIO_MUX_30 | GPIO_MUX_31);
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poke32(GPIO_MUX, value);
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/*
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* Enable Hardware I2C power.
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* TODO: Check if we need to enable GPIO power?
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*/
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sm750_enable_i2c(1);
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/* Enable the I2C Controller and set the bus speed mode */
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value = peek32(I2C_CTRL) & ~(I2C_CTRL_MODE | I2C_CTRL_EN);
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if (bus_speed_mode)
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value |= I2C_CTRL_MODE;
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value |= I2C_CTRL_EN;
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poke32(I2C_CTRL, value);
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return 0;
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}
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void sm750_hw_i2c_close(void)
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{
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unsigned int value;
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/* Disable I2C controller */
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value = peek32(I2C_CTRL) & ~I2C_CTRL_EN;
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poke32(I2C_CTRL, value);
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/* Disable I2C Power */
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sm750_enable_i2c(0);
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/* Set GPIO 30 & 31 back as GPIO pins */
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value = peek32(GPIO_MUX);
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value &= ~GPIO_MUX_30;
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value &= ~GPIO_MUX_31;
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poke32(GPIO_MUX, value);
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}
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static long hw_i2c_wait_tx_done(void)
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{
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unsigned int timeout;
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/* Wait until the transfer is completed. */
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timeout = HWI2C_WAIT_TIMEOUT;
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while (!(peek32(I2C_STATUS) & I2C_STATUS_TX) && (timeout != 0))
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timeout--;
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if (timeout == 0)
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return -1;
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return 0;
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}
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/*
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* This function writes data to the i2c slave device registers.
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*
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* Parameters:
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* addr - i2c Slave device address
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* length - Total number of bytes to be written to the device
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* buf - The buffer that contains the data to be written to the
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* i2c device.
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*
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* Return Value:
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* Total number of bytes those are actually written.
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*/
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static unsigned int hw_i2c_write_data(unsigned char addr,
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unsigned int length,
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unsigned char *buf)
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{
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unsigned char count, i;
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unsigned int total_bytes = 0;
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/* Set the Device Address */
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poke32(I2C_SLAVE_ADDRESS, addr & ~0x01);
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/*
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* Write data.
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* Note:
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* Only 16 byte can be accessed per i2c start instruction.
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*/
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do {
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/*
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* Reset I2C by writing 0 to I2C_RESET register to
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* clear the previous status.
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*/
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poke32(I2C_RESET, 0);
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/* Set the number of bytes to be written */
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if (length < MAX_HWI2C_FIFO)
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count = length - 1;
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else
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count = MAX_HWI2C_FIFO - 1;
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poke32(I2C_BYTE_COUNT, count);
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/* Move the data to the I2C data register */
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for (i = 0; i <= count; i++)
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poke32(I2C_DATA0 + i, *buf++);
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/* Start the I2C */
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poke32(I2C_CTRL, peek32(I2C_CTRL) | I2C_CTRL_CTRL);
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/* Wait until the transfer is completed. */
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if (hw_i2c_wait_tx_done() != 0)
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break;
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/* Subtract length */
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length -= (count + 1);
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/* Total byte written */
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total_bytes += (count + 1);
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} while (length > 0);
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return total_bytes;
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}
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/*
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* This function reads data from the slave device and stores them
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* in the given buffer
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*
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* Parameters:
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* addr - i2c Slave device address
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* length - Total number of bytes to be read
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* buf - Pointer to a buffer to be filled with the data read
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* from the slave device. It has to be the same size as the
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* length to make sure that it can keep all the data read.
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*
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* Return Value:
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* Total number of actual bytes read from the slave device
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*/
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static unsigned int hw_i2c_read_data(unsigned char addr,
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unsigned int length,
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unsigned char *buf)
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{
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unsigned char count, i;
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unsigned int total_bytes = 0;
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/* Set the Device Address */
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poke32(I2C_SLAVE_ADDRESS, addr | 0x01);
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/*
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* Read data and save them to the buffer.
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* Note:
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* Only 16 byte can be accessed per i2c start instruction.
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*/
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do {
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/*
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* Reset I2C by writing 0 to I2C_RESET register to
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* clear all the status.
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*/
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poke32(I2C_RESET, 0);
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/* Set the number of bytes to be read */
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if (length <= MAX_HWI2C_FIFO)
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count = length - 1;
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else
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count = MAX_HWI2C_FIFO - 1;
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poke32(I2C_BYTE_COUNT, count);
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/* Start the I2C */
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poke32(I2C_CTRL, peek32(I2C_CTRL) | I2C_CTRL_CTRL);
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/* Wait until transaction done. */
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if (hw_i2c_wait_tx_done() != 0)
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break;
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/* Save the data to the given buffer */
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for (i = 0; i <= count; i++)
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*buf++ = peek32(I2C_DATA0 + i);
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/* Subtract length by 16 */
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length -= (count + 1);
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/* Number of bytes read. */
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total_bytes += (count + 1);
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} while (length > 0);
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return total_bytes;
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}
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/*
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* This function reads the slave device's register
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*
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* Parameters:
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* deviceAddress - i2c Slave device address which register
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* to be read from
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* registerIndex - Slave device's register to be read
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*
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* Return Value:
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* Register value
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*/
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unsigned char sm750_hw_i2c_read_reg(unsigned char addr, unsigned char reg)
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{
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unsigned char value = 0xFF;
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if (hw_i2c_write_data(addr, 1, ®) == 1)
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hw_i2c_read_data(addr, 1, &value);
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return value;
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}
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/*
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* This function writes a value to the slave device's register
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*
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* Parameters:
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* deviceAddress - i2c Slave device address which register
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* to be written
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* registerIndex - Slave device's register to be written
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* data - Data to be written to the register
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*
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* Result:
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* 0 - Success
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* -1 - Fail
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*/
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int sm750_hw_i2c_write_reg(unsigned char addr,
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unsigned char reg,
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unsigned char data)
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{
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unsigned char value[2];
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value[0] = reg;
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value[1] = data;
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if (hw_i2c_write_data(addr, 2, value) == 2)
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return 0;
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return -1;
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}
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#endif
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