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/*
* clk-synthesizer.c
*
* Clock synthesizer apis
*
* Copyright (C) 2016, Texas Instruments, Incorporated - http://www.ti.com/
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/arch/clk_synthesizer.h>
#include <i2c.h>
/**
* clk_synthesizer_reg_read - Read register from synthesizer.
* @addr: addr within the i2c device
* buf: Buffer to which value is to be read.
*
* For reading the register from this clock synthesizer, a command needs to
* be send along with enabling byte read more, and then read can happen.
* Returns 0 on success
*/
static int clk_synthesizer_reg_read(int addr, uint8_t *buf)
{
int rc;
/* Enable Bye read */
addr = addr | CLK_SYNTHESIZER_BYTE_MODE;
/* Send the command byte */
rc = i2c_write(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, buf, 1);
if (rc)
printf("Failed to send command to clock synthesizer\n");
/* Read the Data */
return i2c_read(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, buf, 1);
}
/**
* clk_synthesizer_reg_write - Write a value to register in synthesizer.
* @addr: addr within the i2c device
* val: Value to be written in the addr.
*
* Enable the byte read mode in the address and start the i2c transfer.
* Returns 0 on success
*/
static int clk_synthesizer_reg_write(int addr, uint8_t val)
{
uint8_t cmd[2];
int rc = 0;
/* Enable byte write */
cmd[0] = addr | CLK_SYNTHESIZER_BYTE_MODE;
cmd[1] = val;
rc = i2c_write(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, cmd, 2);
if (rc)
printf("Clock synthesizer reg write failed at addr = 0x%x\n",
addr);
return rc;
}
/**
* setup_clock_syntherizer - Program the clock synthesizer to get the desired
* frequency.
* @data: Data containing the desired output
*
* This is a PLL-based high performance synthesizer which gives 3 outputs
* as per the PLL_DIV and load capacitor programmed.
*/
int setup_clock_synthesizer(struct clk_synth *data)
{
int rc;
uint8_t val;
rc = i2c_probe(CLK_SYNTHESIZER_I2C_ADDR);
if (rc) {
printf("i2c probe failed at address 0x%x\n",
CLK_SYNTHESIZER_I2C_ADDR);
return rc;
}
rc = clk_synthesizer_reg_read(CLK_SYNTHESIZER_ID_REG, &val);
if (val != data->id)
return rc;
/* Crystal Load capacitor selection */
rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_XCSEL, data->capacitor);
if (rc)
return rc;
rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_MUX_REG, data->mux);
if (rc)
return rc;
rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_PDIV2_REG, data->pdiv2);
if (rc)
return rc;
rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_PDIV3_REG, data->pdiv3);
if (rc)
return rc;
return 0;
}
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