zephyr/drivers/i2c/i2c_dw.c
Kumar Gala 9eddc82be3 i2c: remove I2C Slave Read config
The I2C Slave Read support isn't well defined and not actually supported
by any i2c driver at this point.  We can add this back when slave mode
is more thought out.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-07-07 10:01:38 -05:00

776 lines
18 KiB
C

/* 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 <i2c.h>
#include <kernel.h>
#include <init.h>
#include <arch/cpu.h>
#include <string.h>
#include <board.h>
#include <errno.h>
#include <sys_io.h>
#include <misc/util.h>
#ifdef CONFIG_SHARED_IRQ
#include <shared_irq.h>
#endif
#ifdef CONFIG_IOAPIC
#include <drivers/ioapic.h>
#endif
#include "i2c_dw.h"
#include "i2c_dw_registers.h"
#define SYS_LOG_LEVEL CONFIG_SYS_LOG_I2C_LEVEL
#include <logging/sys_log.h>
static inline void _i2c_dw_data_ask(struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
u32_t data;
u8_t tx_empty;
s8_t rx_empty;
u8_t cnt;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
/* No more bytes to request, so command queue is no longer needed */
if (dw->request_bytes == 0) {
regs->ic_intr_mask.bits.tx_empty = 0;
return;
}
/* How many bytes we can actually ask */
rx_empty = (I2C_DW_FIFO_DEPTH - regs->ic_rxflr) - 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 = I2C_DW_FIFO_DEPTH - regs->ic_txflr;
/* Figure out how many bytes we can request */
cnt = min(I2C_DW_FIFO_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 == 1)) {
data |= IC_DATA_CMD_STOP;
}
regs->ic_data_cmd.raw = data;
dw->rx_pending++;
dw->request_bytes--;
cnt--;
}
}
static void _i2c_dw_data_read(struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
while (regs->ic_status.bits.rfne && (dw->xfr_len > 0)) {
dw->xfr_buf[0] = regs->ic_data_cmd.raw;
dw->xfr_buf++;
dw->xfr_len--;
dw->rx_pending--;
if (dw->xfr_len == 0) {
break;
}
}
/* Nothing to receive anymore */
if (dw->xfr_len == 0) {
dw->state &= ~I2C_DW_CMD_RECV;
return;
}
}
static int _i2c_dw_data_send(struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
u32_t data = 0;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
/* Nothing to send anymore, mask the interrupt */
if (dw->xfr_len == 0) {
regs->ic_intr_mask.bits.tx_empty = 0;
dw->state &= ~I2C_DW_CMD_SEND;
return 0;
}
while (regs->ic_status.bits.tfnf && (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 == 1) && (dw->xfr_flags & I2C_MSG_STOP)) {
data |= IC_DATA_CMD_STOP;
}
regs->ic_data_cmd.raw = data;
dw->xfr_len--;
dw->xfr_buf++;
if (regs->ic_intr_stat.bits.tx_abrt) {
return -EIO;
}
}
return 0;
}
static inline void _i2c_dw_transfer_complete(struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
u32_t value;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
regs->ic_intr_mask.raw = DW_DISABLE_ALL_I2C_INT;
value = regs->ic_clr_intr;
k_sem_give(&dw->device_sync_sem);
}
static void i2c_dw_isr(void *arg)
{
struct device *port = (struct device *)arg;
struct i2c_dw_dev_config * const dw = port->driver_data;
union ic_interrupt_register intr_stat;
u32_t value;
int ret = 0;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
/* Cache ic_intr_stat for processing, so there is no need to read
* the register multiple times.
*/
intr_stat.raw = regs->ic_intr_stat.raw;
#if CONFIG_SHARED_IRQ
/* If using with shared IRQ, this function will be called
* by the shared IRQ driver. So check here if the interrupt
* is coming from the I2C controller (or somewhere else).
*/
if (!intr_stat.raw) {
return;
}
#endif
/*
* 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)
*/
SYS_LOG_DBG("I2C: interrupt received");
/* Check if we are configured as a master device */
if (regs->ic_con.bits.master_mode) {
/* 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 == 0)
&& !(dw->xfr_flags & I2C_MSG_STOP))
|| (ret != 0)) {
goto done;
}
}
}
/* STOP detected: finish processing this message */
if (intr_stat.bits.stop_det) {
value = regs->ic_clr_stop_det;
goto done;
}
return;
done:
_i2c_dw_transfer_complete(port);
}
static int _i2c_dw_setup(struct device *dev, u16_t slave_address)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
u32_t value;
union ic_con_register ic_con;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
ic_con.raw = 0;
/* Disable the device controller to be able set TAR */
regs->ic_enable.bits.enable = 0;
/* Disable interrupts */
regs->ic_intr_mask.raw = 0;
/* Clear interrupts */
value = regs->ic_clr_intr;
/* Set master or slave mode - (initialization = slave) */
if (dw->app_config.bits.is_master_device) {
/*
* Make sure to set both the master_mode and slave_disable_bit
* to both 0 or both 1
*/
SYS_LOG_DBG("I2C: host configured as Master Device");
ic_con.bits.master_mode = 1;
ic_con.bits.slave_disable = 1;
} else {
return -EINVAL;
}
ic_con.bits.restart_en = 1;
/* Set addressing mode - (initialization = 7 bit) */
if (dw->app_config.bits.use_10_bit_addr) {
SYS_LOG_DBG("I2C: using 10-bit address");
ic_con.bits.addr_master_10bit = 1;
ic_con.bits.addr_slave_10bit = 1;
}
/* Setup the clock frequency and speed mode */
switch (dw->app_config.bits.speed) {
case I2C_SPEED_STANDARD:
SYS_LOG_DBG("I2C: speed set to STANDARD");
regs->ic_ss_scl_lcnt = dw->lcnt;
regs->ic_ss_scl_hcnt = dw->hcnt;
ic_con.bits.speed = I2C_DW_SPEED_STANDARD;
break;
case I2C_SPEED_FAST:
/* fall through */
case I2C_SPEED_FAST_PLUS:
SYS_LOG_DBG("I2C: speed set to FAST or FAST_PLUS");
regs->ic_fs_scl_lcnt = dw->lcnt;
regs->ic_fs_scl_hcnt = dw->hcnt;
ic_con.bits.speed = I2C_DW_SPEED_FAST;
break;
case I2C_SPEED_HIGH:
if (!dw->support_hs_mode) {
return -EINVAL;
}
SYS_LOG_DBG("I2C: speed set to HIGH");
regs->ic_hs_scl_lcnt = dw->lcnt;
regs->ic_hs_scl_hcnt = dw->hcnt;
ic_con.bits.speed = I2C_DW_SPEED_HIGH;
break;
default:
SYS_LOG_DBG("I2C: invalid speed requested");
return -EINVAL;
}
SYS_LOG_DBG("I2C: lcnt = %d", dw->lcnt);
SYS_LOG_DBG("I2C: hcnt = %d", dw->hcnt);
/* Set the IC_CON register */
regs->ic_con = ic_con;
/* 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.
*/
regs->ic_rx_tl = 0;
/* 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.
*/
regs->ic_tx_tl = 0;
if (regs->ic_con.bits.master_mode) {
/* Set address of target slave */
regs->ic_tar.bits.ic_tar = slave_address;
} else {
/* Set slave address for device */
regs->ic_sar.bits.ic_sar = slave_address;
}
return 0;
}
static int i2c_dw_transfer(struct device *dev,
struct i2c_msg *msgs, u8_t num_msgs,
u16_t slave_address)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
struct i2c_msg *cur_msg = msgs;
u8_t msg_left = num_msgs;
u8_t pflags;
int ret;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
__ASSERT_NO_MSG(msgs);
if (!num_msgs) {
return 0;
}
/* First step, check if there is current activity */
if ((regs->ic_status.bits.activity) || (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 */
regs->ic_enable.bits.enable = 1;
/*
* While waiting at device_sync_sem, kernel can switch to idle
* task which in turn can call _sys_soc_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 = 0;
/* 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 == 1) {
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 = 0;
} else {
dw->state |= I2C_DW_CMD_RECV;
dw->request_bytes = dw->xfr_len;
}
/* Enable interrupts to trigger ISR */
if (regs->ic_con.bits.master_mode) {
/* Enable necessary interrupts */
regs->ic_intr_mask.raw = (DW_ENABLE_TX_INT_I2C_MASTER |
DW_ENABLE_RX_INT_I2C_MASTER);
} else {
/* Enable necessary interrupts */
regs->ic_intr_mask.raw = DW_ENABLE_TX_INT_I2C_SLAVE;
}
/* 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(struct device *dev, u32_t config)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
u32_t value = 0;
u32_t rc = 0;
volatile struct i2c_dw_registers * const regs =
(struct i2c_dw_registers *)dw->base_address;
dw->app_config.raw = config;
/* Make sure we have a supported speed for the DesignWare model */
/* and have setup the clock frequency and speed mode */
switch (dw->app_config.bits.speed) {
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 <= (regs->ic_fs_spklen + 7)) {
value = regs->ic_fs_spklen + 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 <= (regs->ic_fs_spklen + 5)) {
value = regs->ic_fs_spklen + 6;
} else {
value = I2C_STD_HCNT;
}
dw->hcnt = value;
break;
case I2C_SPEED_FAST:
/* fall through */
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 <= (regs->ic_fs_spklen + 7)) {
value = regs->ic_fs_spklen + 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 <= (regs->ic_fs_spklen + 5)) {
value = regs->ic_fs_spklen + 6;
} else {
value = I2C_FS_HCNT;
}
dw->hcnt = value;
break;
case I2C_SPEED_HIGH:
if (dw->support_hs_mode) {
if (I2C_HS_LCNT <= (regs->ic_hs_spklen + 7)) {
value = regs->ic_hs_spklen + 8;
} else {
value = I2C_HS_LCNT;
}
dw->lcnt = value;
if (I2C_HS_HCNT <= (regs->ic_hs_spklen + 5)) {
value = regs->ic_hs_spklen + 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 = regs->ic_clr_intr;
/*
* 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.bits.is_master_device = 1;
return rc;
}
static const struct i2c_driver_api funcs = {
.configure = i2c_dw_runtime_configure,
.transfer = i2c_dw_transfer,
};
#ifdef CONFIG_PCI
static inline int i2c_dw_pci_setup(struct device *dev)
{
struct i2c_dw_dev_config * const dw = dev->driver_data;
pci_bus_scan_init();
if (!pci_bus_scan(&dw->pci_dev)) {
SYS_LOG_DBG("Could not find device");
return 0;
}
#ifdef CONFIG_PCI_ENUMERATION
dw->base_address = dw->pci_dev.addr;
#endif
pci_enable_regs(&dw->pci_dev);
pci_show(&dw->pci_dev);
return 1;
}
#else
#define i2c_dw_pci_setup(_unused_) (1)
#endif /* CONFIG_PCI */
static int i2c_dw_initialize(struct device *port)
{
const struct i2c_dw_rom_config * const rom = port->config->config_info;
struct i2c_dw_dev_config * const dev = port->driver_data;
volatile struct i2c_dw_registers *regs;
if (!i2c_dw_pci_setup(port)) {
port->driver_api = NULL;
return -EIO;
}
k_sem_init(&dev->device_sync_sem, 0, UINT_MAX);
regs = (struct i2c_dw_registers *) dev->base_address;
/* verify that we have a valid DesignWare register first */
if (regs->ic_comp_type != I2C_DW_MAGIC_KEY) {
port->driver_api = NULL;
SYS_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
*/
if (regs->ic_con.bits.speed == I2C_DW_SPEED_HIGH) {
SYS_LOG_DBG("I2C: high speed supported");
dev->support_hs_mode = true;
} else {
SYS_LOG_DBG("I2C: high speed NOT supported");
dev->support_hs_mode = false;
}
rom->config_func(port);
if (i2c_dw_runtime_configure(port, dev->app_config.raw) != 0) {
SYS_LOG_DBG("I2C: Cannot set default configuration 0x%x",
dev->app_config.raw);
return -EIO;
}
dev->state = I2C_DW_STATE_READY;
return 0;
}
/* system bindings */
#if CONFIG_I2C_0
static void i2c_config_0(struct device *port);
static const struct i2c_dw_rom_config i2c_config_dw_0 = {
#ifdef CONFIG_I2C_DW_0_IRQ_DIRECT
.irq_num = I2C_DW_0_IRQ,
#endif
.config_func = i2c_config_0,
#ifdef CONFIG_GPIO_DW_0_IRQ_SHARED
.shared_irq_dev_name = CONFIG_I2C_DW_0_IRQ_SHARED_NAME,
#endif
};
static struct i2c_dw_dev_config i2c_0_runtime = {
.base_address = I2C_DW_0_BASE_ADDR,
.app_config.raw = CONFIG_I2C_0_DEFAULT_CFG,
#if CONFIG_PCI
.pci_dev.class_type = I2C_DW_PCI_CLASS,
.pci_dev.bus = I2C_DW_0_PCI_BUS,
.pci_dev.dev = I2C_DW_0_PCI_DEV,
.pci_dev.vendor_id = I2C_DW_PCI_VENDOR_ID,
.pci_dev.device_id = I2C_DW_PCI_DEVICE_ID,
.pci_dev.function = I2C_DW_0_PCI_FUNCTION,
.pci_dev.bar = I2C_DW_0_PCI_BAR,
#endif
};
DEVICE_AND_API_INIT(i2c_0, CONFIG_I2C_0_NAME, &i2c_dw_initialize,
&i2c_0_runtime, &i2c_config_dw_0,
POST_KERNEL, CONFIG_I2C_INIT_PRIORITY,
&funcs);
static void i2c_config_0(struct device *port)
{
#if defined(CONFIG_I2C_DW_0_IRQ_DIRECT)
IRQ_CONNECT(I2C_DW_0_IRQ, CONFIG_I2C_0_IRQ_PRI,
i2c_dw_isr, DEVICE_GET(i2c_0), I2C_DW_IRQ_FLAGS);
irq_enable(I2C_DW_0_IRQ);
#elif defined(CONFIG_I2C_DW_0_IRQ_SHARED)
const struct i2c_dw_rom_config * const config =
port->config->config_info;
struct device *shared_irq_dev;
shared_irq_dev = device_get_binding(config->shared_irq_dev_name);
shared_irq_isr_register(shared_irq_dev, (isr_t)i2c_dw_isr, port);
shared_irq_enable(shared_irq_dev, port);
#endif
}
#endif /* CONFIG_I2C_0 */
/*
* Adding in I2C1
*/
#if CONFIG_I2C_1
static void i2c_config_1(struct device *port);
static const struct i2c_dw_rom_config i2c_config_dw_1 = {
.irq_num = I2C_DW_1_IRQ,
.config_func = i2c_config_1,
};
static struct i2c_dw_dev_config i2c_1_runtime = {
.base_address = I2C_DW_1_BASE_ADDR,
.app_config.raw = CONFIG_I2C_1_DEFAULT_CFG,
#if CONFIG_PCI
.pci_dev.class_type = I2C_DW_PCI_CLASS,
.pci_dev.bus = I2C_DW_1_PCI_BUS,
.pci_dev.dev = I2C_DW_1_PCI_DEV,
.pci_dev.vendor_id = I2C_DW_PCI_VENDOR_ID,
.pci_dev.device_id = I2C_DW_PCI_DEVICE_ID,
.pci_dev.function = I2C_DW_1_PCI_FUNCTION,
.pci_dev.bar = I2C_DW_1_PCI_BAR,
#endif
};
DEVICE_AND_API_INIT(i2c_1, CONFIG_I2C_1_NAME, &i2c_dw_initialize,
&i2c_1_runtime, &i2c_config_dw_1,
POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT,
&funcs);
static void i2c_config_1(struct device *port)
{
IRQ_CONNECT(I2C_DW_1_IRQ, CONFIG_I2C_1_IRQ_PRI,
i2c_dw_isr, DEVICE_GET(i2c_1), I2C_DW_IRQ_FLAGS);
irq_enable(I2C_DW_1_IRQ);
}
#endif /* CONFIG_I2C_1 */