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zephyr/drivers/i2c/i2c_dw.c

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/* dw_i2c.c - I2C file for Design Ware */
/*
* Copyright (c) 2015 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stddef.h>
#include <zephyr/types.h>
#include <stdlib.h>
#include <stdbool.h>
#include <drivers/i2c.h>
#include <kernel.h>
#include <init.h>
#include <arch/cpu.h>
#include <string.h>
#include <soc.h>
#include <errno.h>
#include <sys/sys_io.h>
#include <sys/util.h>
#ifdef CONFIG_IOAPIC
#include <drivers/interrupt_controller/ioapic.h>
#endif
#include "i2c_dw.h"
#include "i2c_dw_registers.h"
#define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
#include <logging/log.h>
LOG_MODULE_REGISTER(i2c_dw);
#include "i2c-priv.h"
static inline uint32_t get_regs(const struct device *dev)
{
return (uint32_t)DEVICE_MMIO_GET(dev);
}
static inline void i2c_dw_data_ask(const struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->data;
uint32_t data;
uint8_t tx_empty;
int8_t rx_empty;
uint8_t cnt;
uint8_t rx_buffer_depth, tx_buffer_depth;
union ic_comp_param_1_register ic_comp_param_1;
uint32_t reg_base = get_regs(dev);
/* No more bytes to request, so command queue is no longer needed */
if (dw->request_bytes == 0U) {
clear_bit_intr_mask_tx_empty(reg_base);
return;
}
/* Get the FIFO depth that could be from 2 to 256 from HW spec */
ic_comp_param_1.raw = read_comp_param_1(reg_base);
rx_buffer_depth = ic_comp_param_1.bits.rx_buffer_depth + 1;
tx_buffer_depth = ic_comp_param_1.bits.tx_buffer_depth + 1;
/* How many bytes we can actually ask */
rx_empty = (rx_buffer_depth - read_rxflr(reg_base)) - dw->rx_pending;
if (rx_empty < 0) {
/* RX FIFO expected to be full.
* So don't request any bytes, yet.
*/
return;
}
/* How many empty slots in TX FIFO (as command queue) */
tx_empty = tx_buffer_depth - read_txflr(reg_base);
/* Figure out how many bytes we can request */
cnt = MIN(rx_buffer_depth, dw->request_bytes);
cnt = MIN(MIN(tx_empty, rx_empty), cnt);
while (cnt > 0) {
/* Tell controller to get another byte */
data = IC_DATA_CMD_CMD;
/* Send RESTART if needed */
if (dw->xfr_flags & I2C_MSG_RESTART) {
data |= IC_DATA_CMD_RESTART;
dw->xfr_flags &= ~(I2C_MSG_RESTART);
}
/* After receiving the last byte, send STOP if needed */
if ((dw->xfr_flags & I2C_MSG_STOP)
&& (dw->request_bytes == 1U)) {
data |= IC_DATA_CMD_STOP;
}
write_cmd_data(data, reg_base);
dw->rx_pending++;
dw->request_bytes--;
cnt--;
}
}
static void i2c_dw_data_read(const struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->data;
uint32_t reg_base = get_regs(dev);
while (test_bit_status_rfne(reg_base) && (dw->xfr_len > 0)) {
dw->xfr_buf[0] = (uint8_t)read_cmd_data(reg_base);
dw->xfr_buf++;
dw->xfr_len--;
dw->rx_pending--;
if (dw->xfr_len == 0U) {
break;
}
}
/* Nothing to receive anymore */
if (dw->xfr_len == 0U) {
dw->state &= ~I2C_DW_CMD_RECV;
return;
}
}
static int i2c_dw_data_send(const struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->data;
uint32_t data = 0U;
uint32_t reg_base = get_regs(dev);
/* Nothing to send anymore, mask the interrupt */
if (dw->xfr_len == 0U) {
clear_bit_intr_mask_tx_empty(reg_base);
dw->state &= ~I2C_DW_CMD_SEND;
return 0;
}
while (test_bit_status_tfnt(reg_base) && (dw->xfr_len > 0)) {
/* We have something to transmit to a specific host */
data = dw->xfr_buf[0];
/* Send RESTART if needed */
if (dw->xfr_flags & I2C_MSG_RESTART) {
data |= IC_DATA_CMD_RESTART;
dw->xfr_flags &= ~(I2C_MSG_RESTART);
}
/* Send STOP if needed */
if ((dw->xfr_len == 1U) && (dw->xfr_flags & I2C_MSG_STOP)) {
data |= IC_DATA_CMD_STOP;
}
write_cmd_data(data, reg_base);
dw->xfr_len--;
dw->xfr_buf++;
if (test_bit_intr_stat_tx_abrt(reg_base)) {
return -EIO;
}
}
return 0;
}
static inline void i2c_dw_transfer_complete(const struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->data;
uint32_t value;
uint32_t reg_base = get_regs(dev);
write_intr_mask(DW_DISABLE_ALL_I2C_INT, reg_base);
value = read_clr_intr(reg_base);
k_sem_give(&dw->device_sync_sem);
}
static void i2c_dw_isr(void *arg)
{
const struct device *port = (const struct device *)arg;
struct i2c_dw_dev_config * const dw = port->data;
union ic_interrupt_register intr_stat;
uint32_t value;
int ret = 0;
uint32_t reg_base = get_regs(port);
/* Cache ic_intr_stat for processing, so there is no need to read
* the register multiple times.
*/
intr_stat.raw = read_intr_stat(reg_base);
/*
* Causes of an interrupt:
* - STOP condition is detected
* - Transfer is aborted
* - Transmit FIFO is empty
* - Transmit FIFO has overflowed
* - Receive FIFO is full
* - Receive FIFO has overflowed
* - Received FIFO has underrun
* - Transmit data is required (tx_req)
* - Receive data is available (rx_avail)
*/
LOG_DBG("I2C: interrupt received");
/* Check if we are configured as a master device */
if (test_bit_con_master_mode(reg_base)) {
/* Bail early if there is any error. */
if ((DW_INTR_STAT_TX_ABRT | DW_INTR_STAT_TX_OVER |
DW_INTR_STAT_RX_OVER | DW_INTR_STAT_RX_UNDER) &
intr_stat.raw) {
dw->state = I2C_DW_CMD_ERROR;
goto done;
}
/* Check if the RX FIFO reached threshold */
if (intr_stat.bits.rx_full) {
i2c_dw_data_read(port);
}
/* Check if the TX FIFO is ready for commands.
* TX FIFO also serves as command queue where read requests
* are written to TX FIFO.
*/
if (intr_stat.bits.tx_empty) {
if ((dw->xfr_flags & I2C_MSG_RW_MASK)
== I2C_MSG_WRITE) {
ret = i2c_dw_data_send(port);
} else {
i2c_dw_data_ask(port);
}
/* If STOP is not expected, finish processing this
* message if there is nothing left to do anymore.
*/
if (((dw->xfr_len == 0U)
&& !(dw->xfr_flags & I2C_MSG_STOP))
|| (ret != 0)) {
goto done;
}
}
}
/* STOP detected: finish processing this message */
if (intr_stat.bits.stop_det) {
value = read_clr_stop_det(reg_base);
goto done;
}
return;
done:
i2c_dw_transfer_complete(port);
}
static int i2c_dw_setup(const struct device *dev, uint16_t slave_address)
{
struct i2c_dw_dev_config * const dw = dev->data;
uint32_t value;
union ic_con_register ic_con;
union ic_tar_register ic_tar;
uint32_t reg_base = get_regs(dev);
ic_con.raw = 0U;
/* Disable the device controller to be able set TAR */
clear_bit_enable_en(reg_base);
/* Disable interrupts */
write_intr_mask(0, reg_base);
/* Clear interrupts */
value = read_clr_intr(reg_base);
/* Set master or slave mode - (initialization = slave) */
if (I2C_MODE_MASTER & dw->app_config) {
/*
* Make sure to set both the master_mode and slave_disable_bit
* to both 0 or both 1
*/
LOG_DBG("I2C: host configured as Master Device");
ic_con.bits.master_mode = 1U;
ic_con.bits.slave_disable = 1U;
} else {
return -EINVAL;
}
ic_con.bits.restart_en = 1U;
/* Set addressing mode - (initialization = 7 bit) */
if (I2C_ADDR_10_BITS & dw->app_config) {
LOG_DBG("I2C: using 10-bit address");
ic_con.bits.addr_master_10bit = 1U;
ic_con.bits.addr_slave_10bit = 1U;
}
/* Setup the clock frequency and speed mode */
switch (I2C_SPEED_GET(dw->app_config)) {
case I2C_SPEED_STANDARD:
LOG_DBG("I2C: speed set to STANDARD");
write_ss_scl_lcnt(dw->lcnt, reg_base);
write_ss_scl_hcnt(dw->hcnt, reg_base);
ic_con.bits.speed = I2C_DW_SPEED_STANDARD;
break;
case I2C_SPEED_FAST:
__fallthrough;
case I2C_SPEED_FAST_PLUS:
LOG_DBG("I2C: speed set to FAST or FAST_PLUS");
write_fs_scl_lcnt(dw->lcnt, reg_base);
write_fs_scl_hcnt(dw->hcnt, reg_base);
ic_con.bits.speed = I2C_DW_SPEED_FAST;
break;
case I2C_SPEED_HIGH:
if (!dw->support_hs_mode) {
return -EINVAL;
}
LOG_DBG("I2C: speed set to HIGH");
write_hs_scl_lcnt(dw->lcnt, reg_base);
write_hs_scl_hcnt(dw->hcnt, reg_base);
ic_con.bits.speed = I2C_DW_SPEED_HIGH;
break;
default:
LOG_DBG("I2C: invalid speed requested");
return -EINVAL;
}
LOG_DBG("I2C: lcnt = %d", dw->lcnt);
LOG_DBG("I2C: hcnt = %d", dw->hcnt);
/* Set the IC_CON register */
write_con(ic_con.raw, reg_base);
/* Set RX fifo threshold level.
* Setting it to zero automatically triggers interrupt
* RX_FULL whenever there is data received.
*
* TODO: extend the threshold for multi-byte RX.
*/
write_rx_tl(0, reg_base);
/* Set TX fifo threshold level.
* TX_EMPTY interrupt is triggered only when the
* TX FIFO is truly empty. So that we can let
* the controller do the transfers for longer period
* before we need to fill the FIFO again. This may
* cause some pauses during transfers, but this keeps
* the device from interrupting often.
*/
write_tx_tl(0, reg_base);
ic_tar.raw = read_tar(reg_base);
if (test_bit_con_master_mode(reg_base)) {
/* Set address of target slave */
ic_tar.bits.ic_tar = slave_address;
} else {
/* Set slave address for device */
write_sar(slave_address, reg_base);
}
/* If I2C is being operated in master mode and I2C_DYNAMIC_TAR_UPDATE
* configuration parameter is set to Yes (1), the ic_10bitaddr_master
* bit in ic_tar register would control whether the DW_apb_i2c starts
* its transfers in 7-bit or 10-bit addressing mode.
*/
if (I2C_MODE_MASTER & dw->app_config) {
if (I2C_ADDR_10_BITS & dw->app_config) {
ic_tar.bits.ic_10bitaddr_master = 1U;
} else {
ic_tar.bits.ic_10bitaddr_master = 0U;
}
}
write_tar(ic_tar.raw, reg_base);
return 0;
}
static int i2c_dw_transfer(const struct device *dev,
struct i2c_msg *msgs, uint8_t num_msgs,
uint16_t slave_address)
{
struct i2c_dw_dev_config * const dw = dev->data;
struct i2c_msg *cur_msg = msgs;
uint8_t msg_left = num_msgs;
uint8_t pflags;
int ret;
uint32_t reg_base = get_regs(dev);
__ASSERT_NO_MSG(msgs);
if (!num_msgs) {
return 0;
}
/* First step, check if there is current activity */
if (test_bit_status_activity(reg_base) || (dw->state & I2C_DW_BUSY)) {
return -EIO;
}
dw->state |= I2C_DW_BUSY;
ret = i2c_dw_setup(dev, slave_address);
if (ret) {
dw->state = I2C_DW_STATE_READY;
return ret;
}
/* Enable controller */
set_bit_enable_en(reg_base);
/*
* While waiting at device_sync_sem, kernel can switch to idle
* task which in turn can call pm_system_suspend() hook of Power
* Management App (PMA).
* device_busy_set() call here, would indicate to PMA that it should not
* execute PM policies that would turn off this ip block, causing an
* ongoing hw transaction to be left in an inconsistent state.
* Note : This is just a sample to show a possible use of the API, it is
* upto the driver expert to see, if he actually needs it here, or
* somewhere else, or not needed as the driver's suspend()/resume()
* can handle everything
*/
device_busy_set(dev);
/* Process all the messages */
while (msg_left > 0) {
pflags = dw->xfr_flags;
dw->xfr_buf = cur_msg->buf;
dw->xfr_len = cur_msg->len;
dw->xfr_flags = cur_msg->flags;
dw->rx_pending = 0U;
/* Need to RESTART if changing transfer direction */
if ((pflags & I2C_MSG_RW_MASK)
!= (dw->xfr_flags & I2C_MSG_RW_MASK)) {
dw->xfr_flags |= I2C_MSG_RESTART;
}
/* Send STOP if this is the last message */
if (msg_left == 1U) {
dw->xfr_flags |= I2C_MSG_STOP;
}
dw->state &= ~(I2C_DW_CMD_SEND | I2C_DW_CMD_RECV);
if ((dw->xfr_flags & I2C_MSG_RW_MASK) == I2C_MSG_WRITE) {
dw->state |= I2C_DW_CMD_SEND;
dw->request_bytes = 0U;
} else {
dw->state |= I2C_DW_CMD_RECV;
dw->request_bytes = dw->xfr_len;
}
/* Enable interrupts to trigger ISR */
if (test_bit_con_master_mode(reg_base)) {
/* Enable necessary interrupts */
write_intr_mask((DW_ENABLE_TX_INT_I2C_MASTER |
DW_ENABLE_RX_INT_I2C_MASTER), reg_base);
} else {
/* Enable necessary interrupts */
write_intr_mask(DW_ENABLE_TX_INT_I2C_SLAVE, reg_base);
}
/* Wait for transfer to be done */
k_sem_take(&dw->device_sync_sem, K_FOREVER);
if (dw->state & I2C_DW_CMD_ERROR) {
ret = -EIO;
break;
}
/* Something wrong if there is something left to do */
if (dw->xfr_len > 0) {
ret = -EIO;
break;
}
cur_msg++;
msg_left--;
}
device_busy_clear(dev);
dw->state = I2C_DW_STATE_READY;
return ret;
}
static int i2c_dw_runtime_configure(const struct device *dev, uint32_t config)
{
struct i2c_dw_dev_config * const dw = dev->data;
uint32_t value = 0U;
uint32_t rc = 0U;
uint32_t reg_base = get_regs(dev);
dw->app_config = config;
/* Make sure we have a supported speed for the DesignWare model */
/* and have setup the clock frequency and speed mode */
switch (I2C_SPEED_GET(dw->app_config)) {
case I2C_SPEED_STANDARD:
/* Following the directions on DW spec page 59, IC_SS_SCL_LCNT
* must have register values larger than IC_FS_SPKLEN + 7
*/
if (I2C_STD_LCNT <= (read_fs_spklen(reg_base) + 7)) {
value = read_fs_spklen(reg_base) + 8;
} else {
value = I2C_STD_LCNT;
}
dw->lcnt = value;
/* Following the directions on DW spec page 59, IC_SS_SCL_HCNT
* must have register values larger than IC_FS_SPKLEN + 5
*/
if (I2C_STD_HCNT <= (read_fs_spklen(reg_base) + 5)) {
value = read_fs_spklen(reg_base) + 6;
} else {
value = I2C_STD_HCNT;
}
dw->hcnt = value;
break;
case I2C_SPEED_FAST:
__fallthrough;
case I2C_SPEED_FAST_PLUS:
/*
* Following the directions on DW spec page 59, IC_FS_SCL_LCNT
* must have register values larger than IC_FS_SPKLEN + 7
*/
if (I2C_FS_LCNT <= (read_fs_spklen(reg_base) + 7)) {
value = read_fs_spklen(reg_base) + 8;
} else {
value = I2C_FS_LCNT;
}
dw->lcnt = value;
/*
* Following the directions on DW spec page 59, IC_FS_SCL_HCNT
* must have register values larger than IC_FS_SPKLEN + 5
*/
if (I2C_FS_HCNT <= (read_fs_spklen(reg_base) + 5)) {
value = read_fs_spklen(reg_base) + 6;
} else {
value = I2C_FS_HCNT;
}
dw->hcnt = value;
break;
case I2C_SPEED_HIGH:
if (dw->support_hs_mode) {
if (I2C_HS_LCNT <= (read_hs_spklen(reg_base) + 7)) {
value = read_hs_spklen(reg_base) + 8;
} else {
value = I2C_HS_LCNT;
}
dw->lcnt = value;
if (I2C_HS_HCNT <= (read_hs_spklen(reg_base) + 5)) {
value = read_hs_spklen(reg_base) + 6;
} else {
value = I2C_HS_HCNT;
}
dw->hcnt = value;
} else {
rc = -EINVAL;
}
break;
default:
/* TODO change */
rc = -EINVAL;
}
/*
* Clear any interrupts currently waiting in the controller
*/
value = read_clr_intr(reg_base);
/*
* TEMPORARY HACK - The I2C does not work in any mode other than Master
* currently. This "hack" forces us to always be configured for master
* mode, until we can verify that Slave mode works correctly.
*/
dw->app_config |= I2C_MODE_MASTER;
return rc;
}
static const struct i2c_driver_api funcs = {
.configure = i2c_dw_runtime_configure,
.transfer = i2c_dw_transfer,
};
static int i2c_dw_initialize(const struct device *dev)
{
const struct i2c_dw_rom_config * const rom = dev->config;
struct i2c_dw_dev_config * const dw = dev->data;
union ic_con_register ic_con;
uint32_t reg_base = get_regs(dev);
#if DT_ANY_INST_ON_BUS_STATUS_OKAY(pcie)
if (rom->pcie) {
struct pcie_mbar mbar;
if (!pcie_probe(rom->pcie_bdf, rom->pcie_id)) {
return -EINVAL;
}
pcie_get_mbar(rom->pcie_bdf, 0, &mbar);
pcie_set_cmd(rom->pcie_bdf, PCIE_CONF_CMDSTAT_MEM, true);
device_map(DEVICE_MMIO_RAM_PTR(dev), mbar.phys_addr,
mbar.size, K_MEM_CACHE_NONE);
} else
#endif
{
DEVICE_MMIO_MAP(dev, K_MEM_CACHE_NONE);
}
k_sem_init(&dw->device_sync_sem, 0, K_SEM_MAX_LIMIT);
/* verify that we have a valid DesignWare register first */
if (read_comp_type(reg_base) != I2C_DW_MAGIC_KEY) {
LOG_DBG("I2C: DesignWare magic key not found, check base "
"address. Stopping initialization");
return -EIO;
}
/*
* grab the default value on initialization. This should be set to the
* IC_MAX_SPEED_MODE in the hardware. If it does support high speed we
* can move provide support for it
*/
ic_con.raw = read_con(reg_base);
if (ic_con.bits.speed == I2C_DW_SPEED_HIGH) {
LOG_DBG("I2C: high speed supported");
dw->support_hs_mode = true;
} else {
LOG_DBG("I2C: high speed NOT supported");
dw->support_hs_mode = false;
}
rom->config_func(dev);
dw->app_config = I2C_MODE_MASTER | i2c_map_dt_bitrate(rom->bitrate);
if (i2c_dw_runtime_configure(dev, dw->app_config) != 0) {
LOG_DBG("I2C: Cannot set default configuration");
return -EIO;
}
dw->state = I2C_DW_STATE_READY;
return 0;
}
#define I2C_DW_INIT_PCIE0(n)
#define I2C_DW_INIT_PCIE1(n) \
.pcie = true, \
.pcie_bdf = DT_INST_REG_ADDR(n), \
.pcie_id = DT_INST_REG_SIZE(n),
#define I2C_DW_INIT_PCIE(n) \
_CONCAT(I2C_DW_INIT_PCIE, DT_INST_ON_BUS(n, pcie))(n)
#define I2C_DW_IRQ_FLAGS_SENSE0(n) 0
#define I2C_DW_IRQ_FLAGS_SENSE1(n) DT_INST_IRQ(n, sense)
#define I2C_DW_IRQ_FLAGS(n) \
_CONCAT(I2C_DW_IRQ_FLAGS_SENSE, DT_INST_IRQ_HAS_CELL(n, sense))(n)
/* not PCI(e) */
#define I2C_DW_IRQ_CONFIG_PCIE0(n) \
static void i2c_config_##n(const struct device *port) \
{ \
ARG_UNUSED(port); \
IRQ_CONNECT(DT_INST_IRQN(n), DT_INST_IRQ(n, priority), \
i2c_dw_isr, DEVICE_DT_INST_GET(n), \
I2C_DW_IRQ_FLAGS(n)); \
irq_enable(DT_INST_IRQN(n)); \
}
/* PCI(e) with auto IRQ detection */
#define I2C_DW_IRQ_CONFIG_PCIE1(n) \
static void i2c_config_##n(const struct device *port) \
{ \
ARG_UNUSED(port); \
BUILD_ASSERT(DT_INST_IRQN(n) == PCIE_IRQ_DETECT, \
"Only runtime IRQ configuration is supported"); \
BUILD_ASSERT(IS_ENABLED(CONFIG_DYNAMIC_INTERRUPTS), \
"DW I2C PCI needs CONFIG_DYNAMIC_INTERRUPTS"); \
unsigned int irq = pcie_alloc_irq(DT_INST_REG_ADDR(n)); \
if (irq == PCIE_CONF_INTR_IRQ_NONE) { \
return; \
} \
irq_connect_dynamic(irq, DT_INST_IRQ(n, priority), \
(void (*)(const void *))i2c_dw_isr, \
DEVICE_DT_INST_GET(n), \
I2C_DW_IRQ_FLAGS(n)); \
pcie_irq_enable(DT_INST_REG_ADDR(n), irq); \
}
#define I2C_DW_IRQ_CONFIG(n) \
_CONCAT(I2C_DW_IRQ_CONFIG_PCIE, DT_INST_ON_BUS(n, pcie))(n)
#define I2C_DEVICE_INIT_DW(n) \
static void i2c_config_##n(const struct device *port); \
static const struct i2c_dw_rom_config i2c_config_dw_##n = { \
DEVICE_MMIO_ROM_INIT(DT_DRV_INST(n)), \
.config_func = i2c_config_##n, \
.bitrate = DT_INST_PROP(n, clock_frequency), \
I2C_DW_INIT_PCIE(n) \
}; \
static struct i2c_dw_dev_config i2c_##n##_runtime; \
DEVICE_DT_INST_DEFINE(n, &i2c_dw_initialize, NULL, \
&i2c_##n##_runtime, &i2c_config_dw_##n, \
POST_KERNEL, CONFIG_I2C_INIT_PRIORITY, \
&funcs); \
I2C_DW_IRQ_CONFIG(n)
DT_INST_FOREACH_STATUS_OKAY(I2C_DEVICE_INIT_DW)
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