389 lines
11 KiB
C
389 lines
11 KiB
C
/*
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* Copyright (c) 2021 IoT.bzh
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT renesas_rcar_i2c
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#include <errno.h>
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#include <device.h>
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#include <devicetree.h>
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#include <soc.h>
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#include <drivers/i2c.h>
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#include <drivers/clock_control.h>
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#include <drivers/clock_control/rcar_clock_control.h>
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#include <logging/log.h>
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LOG_MODULE_REGISTER(i2c_rcar);
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#include "i2c-priv.h"
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typedef void (*init_func_t)(const struct device *dev);
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struct i2c_rcar_cfg {
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uint32_t reg_addr;
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init_func_t init_func;
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const struct device *clock_dev;
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struct rcar_cpg_clk mod_clk;
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uint32_t bitrate;
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};
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struct i2c_rcar_data {
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uint8_t status_mask;
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struct k_sem int_sem;
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};
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/* Registers */
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#define RCAR_I2C_ICSCR 0x00 /* Slave Control Register */
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#define RCAR_I2C_ICMCR 0x04 /* Master Control Register */
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#define RCAR_I2C_ICSIER 0x10 /* Slave IRQ Enable */
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#define RCAR_I2C_ICMIER 0x14 /* Master IRQ Enable */
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#define RCAR_I2C_ICSSR 0x08 /* Slave Status */
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#define RCAR_I2C_ICMSR 0x0c /* Master Status */
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#define RCAR_I2C_ICCCR 0x18 /* Clock Control Register */
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#define RCAR_I2C_ICSAR 0x1c /* Slave Address Register */
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#define RCAR_I2C_ICMAR 0x20 /* Master Address Register */
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#define RCAR_I2C_ICRXD_ICTXD 0x24 /* Receive Transmit Data Register */
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#define RCAR_I2C_ICFBSCR 0x38 /* First Bit Setup Cycle (Gen3).*/
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#define RCAR_I2C_ICFBSCR_TCYC17 0x0f /* 17*Tcyc */
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#define RCAR_I2C_ICMCR_MDBS BIT(7) /* Master Data Buffer Select */
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#define RCAR_I2C_ICMCR_FSCL BIT(6) /* Forced SCL */
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#define RCAR_I2C_ICMCR_FSDA BIT(5) /* Forced SDA */
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#define RCAR_I2C_ICMCR_OBPC BIT(4) /* Override Bus Pin Control */
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#define RCAR_I2C_ICMCR_MIE BIT(3) /* Master Interface Enable */
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#define RCAR_I2C_ICMCR_TSBE BIT(2) /* Start Byte Transmission Enable */
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#define RCAR_I2C_ICMCR_FSB BIT(1) /* Forced Stop onto the Bus */
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#define RCAR_I2C_ICMCR_ESG BIT(0) /* Enable Start Generation */
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#define RCAR_I2C_ICMCR_MASTER (RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE)
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/* Bits to manage ICMIER and ICMSR registers */
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#define RCAR_I2C_MNR BIT(6) /* Master Nack Received */
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#define RCAR_I2C_MAL BIT(5) /* Master Arbitration lost */
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#define RCAR_I2C_MST BIT(4) /* Master Stop Transmitted */
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#define RCAR_I2C_MDE BIT(3) /* Master Data Empty */
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#define RCAR_I2C_MDT BIT(2) /* Master Data Transmitted */
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#define RCAR_I2C_MDR BIT(1) /* Master Data Received */
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#define RCAR_I2C_MAT BIT(0) /* Master Address Transmitted */
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/* Recommended bitrate settings from official documentation */
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#define RCAR_I2C_ICCCR_CDF_100_KHZ 6
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#define RCAR_I2C_ICCCR_CDF_400_KHZ 6
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#define RCAR_I2C_ICCCR_SCGD_100_KHZ 21
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#define RCAR_I2C_ICCCR_SCGD_400_KHZ 3
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#define MAX_WAIT_US 100
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/* Helper macros for I2C */
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#define DEV_I2C_CFG(dev) \
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((const struct i2c_rcar_cfg *)(dev)->config)
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#define DEV_I2C_DATA(dev) \
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((struct i2c_rcar_data *)(dev)->data)
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static uint32_t i2c_rcar_read(const struct i2c_rcar_cfg *config,
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uint32_t offs)
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{
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return sys_read32(config->reg_addr + offs);
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}
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static void i2c_rcar_write(const struct i2c_rcar_cfg *config,
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uint32_t offs, uint32_t value)
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{
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sys_write32(value, config->reg_addr + offs);
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}
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static void i2c_rcar_isr(const struct device *dev)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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struct i2c_rcar_data *data = DEV_I2C_DATA(dev);
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if (((i2c_rcar_read(config, RCAR_I2C_ICMSR)) & data->status_mask) ==
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data->status_mask) {
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k_sem_give(&data->int_sem);
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i2c_rcar_write(config, RCAR_I2C_ICMIER, 0);
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}
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}
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static int i2c_rcar_wait_for_state(const struct device *dev, uint8_t mask)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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struct i2c_rcar_data *data = DEV_I2C_DATA(dev);
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data->status_mask = mask;
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/* Reset interrupts semaphore */
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k_sem_reset(&data->int_sem);
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/* Enable interrupts */
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i2c_rcar_write(config, RCAR_I2C_ICMIER, mask);
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/* Wait for the interrupts */
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return k_sem_take(&data->int_sem, K_USEC(MAX_WAIT_US));
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}
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static int i2c_rcar_finish(const struct device *dev)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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int ret;
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/* Enable STOP generation */
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i2c_rcar_write(config, RCAR_I2C_ICMCR, RCAR_I2C_ICMCR_MASTER | RCAR_I2C_ICMCR_FSB);
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i2c_rcar_write(config, RCAR_I2C_ICMSR, 0);
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/* Wait for STOP to be transmitted */
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ret = i2c_rcar_wait_for_state(dev, RCAR_I2C_MST);
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i2c_rcar_write(config, RCAR_I2C_ICMSR, 0);
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/* Disable STOP generation */
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i2c_rcar_write(config, RCAR_I2C_ICMCR, RCAR_I2C_ICMCR_MASTER);
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return ret;
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}
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static int i2c_rcar_set_addr(const struct device *dev,
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uint8_t chip, uint8_t read)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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/* Set slave address & transfer mode */
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i2c_rcar_write(config, RCAR_I2C_ICMAR, (chip << 1) | read);
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/* Reset */
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i2c_rcar_write(config, RCAR_I2C_ICMCR, RCAR_I2C_ICMCR_MASTER | RCAR_I2C_ICMCR_ESG);
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/* Clear Status */
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i2c_rcar_write(config, RCAR_I2C_ICMSR, 0);
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/* Wait for address & transfer mode to be transmitted */
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if (read != 0) {
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return i2c_rcar_wait_for_state(dev, RCAR_I2C_MAT | RCAR_I2C_MDR);
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} else {
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return i2c_rcar_wait_for_state(dev, RCAR_I2C_MAT | RCAR_I2C_MDE);
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}
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}
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static int i2c_rcar_transfer_msg(const struct device *dev, struct i2c_msg *msg)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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uint32_t i, reg;
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int ret = 0;
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if ((msg->flags & I2C_MSG_RW_MASK) == I2C_MSG_READ) {
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/* Reading as master */
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i2c_rcar_write(config, RCAR_I2C_ICMCR, RCAR_I2C_ICMCR_MASTER);
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for (i = 0; i < msg->len; i++) {
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if (msg->len - 1 == i) {
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i2c_rcar_write(config, RCAR_I2C_ICMCR, RCAR_I2C_ICMCR_MASTER |
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RCAR_I2C_ICMCR_FSB);
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}
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/* Start data reception */
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reg = i2c_rcar_read(config, RCAR_I2C_ICMSR);
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reg &= ~RCAR_I2C_MDR;
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i2c_rcar_write(config, RCAR_I2C_ICMSR, reg);
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/* Wait for data to be received */
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ret = i2c_rcar_wait_for_state(dev, RCAR_I2C_MDR);
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if (ret != 0) {
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return ret;
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}
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msg->buf[i] = i2c_rcar_read(config, RCAR_I2C_ICRXD_ICTXD) & 0xff;
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}
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} else {
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/* Writing as master */
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for (i = 0; i < msg->len; i++) {
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i2c_rcar_write(config, RCAR_I2C_ICRXD_ICTXD, msg->buf[i]);
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i2c_rcar_write(config, RCAR_I2C_ICMCR, RCAR_I2C_ICMCR_MASTER);
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/* Start data transmission */
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reg = i2c_rcar_read(config, RCAR_I2C_ICMSR);
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reg &= ~RCAR_I2C_MDE;
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i2c_rcar_write(config, RCAR_I2C_ICMSR, reg);
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/* Wait for all data to be transmitted */
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ret = i2c_rcar_wait_for_state(dev, RCAR_I2C_MDE);
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if (ret != 0) {
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return ret;
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}
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}
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}
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return ret;
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}
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static int i2c_rcar_transfer(const struct device *dev,
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struct i2c_msg *msgs, uint8_t num_msgs,
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uint16_t addr)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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uint16_t timeout = 0;
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int ret;
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if (!num_msgs) {
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return 0;
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}
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/* Wait for the bus to be available */
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while ((i2c_rcar_read(config, RCAR_I2C_ICMCR) & RCAR_I2C_ICMCR_FSDA) && (timeout < 10)) {
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k_busy_wait(USEC_PER_MSEC);
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timeout++;
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}
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if (timeout == 10) {
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return -EIO;
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}
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do {
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/* We are not supporting 10-bit addressing */
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if ((msgs->flags & I2C_MSG_ADDR_10_BITS) == I2C_MSG_ADDR_10_BITS) {
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return -ENOTSUP;
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}
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/* Send slave address */
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if (i2c_rcar_set_addr(dev, addr, !!(msgs->flags & I2C_MSG_READ))) {
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return -EIO; /* No ACK received */
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}
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/* Transfer data */
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if (msgs->len) {
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ret = i2c_rcar_transfer_msg(dev, msgs);
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if (ret != 0) {
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return ret;
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}
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}
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/* Finish the transfer */
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if ((msgs->flags & I2C_MSG_STOP) == I2C_MSG_STOP) {
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ret = i2c_rcar_finish(dev);
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if (ret != 0) {
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return ret;
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}
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}
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/* Next message */
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msgs++;
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num_msgs--;
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} while (num_msgs);
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/* Complete without error */
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return 0;
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}
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static int i2c_rcar_configure(const struct device *dev, uint32_t dev_config)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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uint8_t cdf, scgd;
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/* We only support Master mode */
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if ((dev_config & I2C_MODE_MASTER) != I2C_MODE_MASTER) {
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return -ENOTSUP;
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}
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/* We are not supporting 10-bit addressing */
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if ((dev_config & I2C_ADDR_10_BITS) == I2C_ADDR_10_BITS) {
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return -ENOTSUP;
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}
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switch (I2C_SPEED_GET(dev_config)) {
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case I2C_SPEED_STANDARD:
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/* Use recommended value for 100 kHz bus */
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cdf = RCAR_I2C_ICCCR_CDF_100_KHZ;
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scgd = RCAR_I2C_ICCCR_SCGD_100_KHZ;
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break;
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case I2C_SPEED_FAST:
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/* Use recommended value for 400 kHz bus */
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cdf = RCAR_I2C_ICCCR_CDF_400_KHZ;
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scgd = RCAR_I2C_ICCCR_SCGD_400_KHZ;
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break;
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default:
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return -ENOTSUP;
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}
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/* Setting ICCCR to recommended value */
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i2c_rcar_write(config, RCAR_I2C_ICCCR, (scgd << 3) | cdf);
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/* Reset slave mode */
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i2c_rcar_write(config, RCAR_I2C_ICSIER, 0);
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i2c_rcar_write(config, RCAR_I2C_ICSAR, 0);
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i2c_rcar_write(config, RCAR_I2C_ICSCR, 0);
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i2c_rcar_write(config, RCAR_I2C_ICSSR, 0);
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/* Reset master mode */
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i2c_rcar_write(config, RCAR_I2C_ICMIER, 0);
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i2c_rcar_write(config, RCAR_I2C_ICMCR, 0);
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i2c_rcar_write(config, RCAR_I2C_ICMSR, 0);
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i2c_rcar_write(config, RCAR_I2C_ICMAR, 0);
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return 0;
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}
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static int i2c_rcar_init(const struct device *dev)
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{
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const struct i2c_rcar_cfg *config = DEV_I2C_CFG(dev);
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struct i2c_rcar_data *data = DEV_I2C_DATA(dev);
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uint32_t bitrate_cfg;
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int ret;
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k_sem_init(&data->int_sem, 0, 1);
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ret = clock_control_on(config->clock_dev,
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(clock_control_subsys_t *)&config->mod_clk);
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if (ret != 0) {
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return ret;
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}
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bitrate_cfg = i2c_map_dt_bitrate(config->bitrate);
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ret = i2c_rcar_configure(dev, I2C_MODE_MASTER | bitrate_cfg);
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if (ret != 0) {
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return ret;
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}
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config->init_func(dev);
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return 0;
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}
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static const struct i2c_driver_api i2c_rcar_driver_api = {
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.configure = i2c_rcar_configure,
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.transfer = i2c_rcar_transfer,
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};
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/* Device Instantiation */
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#define I2C_RCAR_INIT(n) \
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static void i2c_rcar_##n##_init(const struct device *dev); \
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static const struct i2c_rcar_cfg i2c_rcar_cfg_##n = { \
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.reg_addr = DT_INST_REG_ADDR(n), \
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.init_func = i2c_rcar_##n##_init, \
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.clock_dev = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(n)), \
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.bitrate = DT_INST_PROP(n, clock_frequency), \
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.mod_clk.module = \
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DT_INST_CLOCKS_CELL_BY_IDX(n, 0, module), \
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.mod_clk.domain = \
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DT_INST_CLOCKS_CELL_BY_IDX(n, 0, domain), \
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}; \
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\
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static struct i2c_rcar_data i2c_rcar_data_##n; \
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\
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DEVICE_DT_INST_DEFINE(n, \
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i2c_rcar_init, \
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NULL, \
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&i2c_rcar_data_##n, \
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&i2c_rcar_cfg_##n, \
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POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
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&i2c_rcar_driver_api \
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); \
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static void i2c_rcar_##n##_init(const struct device *dev) \
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{ \
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IRQ_CONNECT(DT_INST_IRQN(n), \
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0, \
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i2c_rcar_isr, \
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DEVICE_DT_INST_GET(n), 0); \
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\
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irq_enable(DT_INST_IRQN(n)); \
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}
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DT_INST_FOREACH_STATUS_OKAY(I2C_RCAR_INIT)
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