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i2c: iproc: Add slave mode support

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Add slave mode support to the iProc I2C driver.

Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Signed-off-by: Michael Cheng <ccheng@broadcom.com>
Signed-off-by: Shreesha Rajashekar <shreesha.rajashekar@broadcom.com>
Signed-off-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Shreesha Rajashekar 2019-04-02 18:18:23 -07:00 committed by Wolfram Sang
parent c24b8d574b
commit f34b8d9093
2 changed files with 299 additions and 6 deletions
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1
drivers/i2c/busses/Kconfig
View File

@ -447,6 +447,7 @@ config I2C_BCM_IPROC
tristate "Broadcom iProc I2C controller"
depends on ARCH_BCM_IPROC || COMPILE_TEST
default ARCH_BCM_IPROC
select I2C_SLAVE
help
If you say yes to this option, support will be included for the
Broadcom iProc I2C controller.

304
drivers/i2c/busses/i2c-bcm-iproc.c
View File

@ -23,11 +23,30 @@
#define CFG_OFFSET 0x00
#define CFG_RESET_SHIFT 31
#define CFG_EN_SHIFT 30
#define CFG_SLAVE_ADDR_0_SHIFT 28
#define CFG_M_RETRY_CNT_SHIFT 16
#define CFG_M_RETRY_CNT_MASK 0x0f
#define TIM_CFG_OFFSET 0x04
#define TIM_CFG_MODE_400_SHIFT 31
#define TIM_RAND_SLAVE_STRETCH_SHIFT 24
#define TIM_RAND_SLAVE_STRETCH_MASK 0x7f
#define TIM_PERIODIC_SLAVE_STRETCH_SHIFT 16
#define TIM_PERIODIC_SLAVE_STRETCH_MASK 0x7f
#define S_CFG_SMBUS_ADDR_OFFSET 0x08
#define S_CFG_EN_NIC_SMB_ADDR3_SHIFT 31
#define S_CFG_NIC_SMB_ADDR3_SHIFT 24
#define S_CFG_NIC_SMB_ADDR3_MASK 0x7f
#define S_CFG_EN_NIC_SMB_ADDR2_SHIFT 23
#define S_CFG_NIC_SMB_ADDR2_SHIFT 16
#define S_CFG_NIC_SMB_ADDR2_MASK 0x7f
#define S_CFG_EN_NIC_SMB_ADDR1_SHIFT 15
#define S_CFG_NIC_SMB_ADDR1_SHIFT 8
#define S_CFG_NIC_SMB_ADDR1_MASK 0x7f
#define S_CFG_EN_NIC_SMB_ADDR0_SHIFT 7
#define S_CFG_NIC_SMB_ADDR0_SHIFT 0
#define S_CFG_NIC_SMB_ADDR0_MASK 0x7f
#define M_FIFO_CTRL_OFFSET 0x0c
#define M_FIFO_RX_FLUSH_SHIFT 31
@ -37,6 +56,14 @@
#define M_FIFO_RX_THLD_SHIFT 8
#define M_FIFO_RX_THLD_MASK 0x3f
#define S_FIFO_CTRL_OFFSET 0x10
#define S_FIFO_RX_FLUSH_SHIFT 31
#define S_FIFO_TX_FLUSH_SHIFT 30
#define S_FIFO_RX_CNT_SHIFT 16
#define S_FIFO_RX_CNT_MASK 0x7f
#define S_FIFO_RX_THLD_SHIFT 8
#define S_FIFO_RX_THLD_MASK 0x3f
#define M_CMD_OFFSET 0x30
#define M_CMD_START_BUSY_SHIFT 31
#define M_CMD_STATUS_SHIFT 25
@ -54,17 +81,36 @@
#define M_CMD_RD_CNT_SHIFT 0
#define M_CMD_RD_CNT_MASK 0xff
#define S_CMD_OFFSET 0x34
#define S_CMD_START_BUSY_SHIFT 31
#define S_CMD_STATUS_SHIFT 23
#define S_CMD_STATUS_MASK 0x07
#define S_CMD_STATUS_SUCCESS 0x0
#define S_CMD_STATUS_TIMEOUT 0x5
#define IE_OFFSET 0x38
#define IE_M_RX_FIFO_FULL_SHIFT 31
#define IE_M_RX_THLD_SHIFT 30
#define IE_M_START_BUSY_SHIFT 28
#define IE_M_TX_UNDERRUN_SHIFT 27
#define IE_S_RX_FIFO_FULL_SHIFT 26
#define IE_S_RX_THLD_SHIFT 25
#define IE_S_RX_EVENT_SHIFT 24
#define IE_S_START_BUSY_SHIFT 23
#define IE_S_TX_UNDERRUN_SHIFT 22
#define IE_S_RD_EVENT_SHIFT 21
#define IS_OFFSET 0x3c
#define IS_M_RX_FIFO_FULL_SHIFT 31
#define IS_M_RX_THLD_SHIFT 30
#define IS_M_START_BUSY_SHIFT 28
#define IS_M_TX_UNDERRUN_SHIFT 27
#define IS_S_RX_FIFO_FULL_SHIFT 26
#define IS_S_RX_THLD_SHIFT 25
#define IS_S_RX_EVENT_SHIFT 24
#define IS_S_START_BUSY_SHIFT 23
#define IS_S_TX_UNDERRUN_SHIFT 22
#define IS_S_RD_EVENT_SHIFT 21
#define M_TX_OFFSET 0x40
#define M_TX_WR_STATUS_SHIFT 31
@ -78,6 +124,18 @@
#define M_RX_DATA_SHIFT 0
#define M_RX_DATA_MASK 0xff
#define S_TX_OFFSET 0x48
#define S_TX_WR_STATUS_SHIFT 31
#define S_TX_DATA_SHIFT 0
#define S_TX_DATA_MASK 0xff
#define S_RX_OFFSET 0x4c
#define S_RX_STATUS_SHIFT 30
#define S_RX_STATUS_MASK 0x03
#define S_RX_PEC_ERR_SHIFT 29
#define S_RX_DATA_SHIFT 0
#define S_RX_DATA_MASK 0xff
#define I2C_TIMEOUT_MSEC 50000
#define M_TX_RX_FIFO_SIZE 64
#define M_RX_FIFO_MAX_THLD_VALUE (M_TX_RX_FIFO_SIZE - 1)
@ -85,6 +143,30 @@
#define M_RX_MAX_READ_LEN 255
#define M_RX_FIFO_THLD_VALUE 50
#define IE_M_ALL_INTERRUPT_SHIFT 27
#define IE_M_ALL_INTERRUPT_MASK 0x1e
#define SLAVE_READ_WRITE_BIT_MASK 0x1
#define SLAVE_READ_WRITE_BIT_SHIFT 0x1
#define SLAVE_MAX_SIZE_TRANSACTION 64
#define SLAVE_CLOCK_STRETCH_TIME 25
#define IE_S_ALL_INTERRUPT_SHIFT 21
#define IE_S_ALL_INTERRUPT_MASK 0x3f
enum i2c_slave_read_status {
I2C_SLAVE_RX_FIFO_EMPTY = 0,
I2C_SLAVE_RX_START,
I2C_SLAVE_RX_DATA,
I2C_SLAVE_RX_END,
};
enum i2c_slave_xfer_dir {
I2C_SLAVE_DIR_READ = 0,
I2C_SLAVE_DIR_WRITE,
I2C_SLAVE_DIR_NONE,
};
enum bus_speed_index {
I2C_SPD_100K = 0,
I2C_SPD_400K,
@ -104,6 +186,9 @@ struct bcm_iproc_i2c_dev {
struct i2c_msg *msg;
struct i2c_client *slave;
enum i2c_slave_xfer_dir xfer_dir;
/* bytes that have been transferred */
unsigned int tx_bytes;
/* bytes that have been read */
@ -117,6 +202,156 @@ struct bcm_iproc_i2c_dev {
#define ISR_MASK (BIT(IS_M_START_BUSY_SHIFT) | BIT(IS_M_TX_UNDERRUN_SHIFT)\
| BIT(IS_M_RX_THLD_SHIFT))
#define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\
| BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT))
static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave);
static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave);
static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
bool enable);
static void bcm_iproc_i2c_slave_init(
struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset)
{
u32 val;
if (need_reset) {
/* put controller in reset */
val = readl(iproc_i2c->base + CFG_OFFSET);
val |= BIT(CFG_RESET_SHIFT);
writel(val, iproc_i2c->base + CFG_OFFSET);
/* wait 100 usec per spec */
udelay(100);
/* bring controller out of reset */
val &= ~(BIT(CFG_RESET_SHIFT));
writel(val, iproc_i2c->base + CFG_OFFSET);
}
/* flush TX/RX FIFOs */
val = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
writel(val, iproc_i2c->base + S_FIFO_CTRL_OFFSET);
/* Maximum slave stretch time */
val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
val &= ~(TIM_RAND_SLAVE_STRETCH_MASK << TIM_RAND_SLAVE_STRETCH_SHIFT);
val |= (SLAVE_CLOCK_STRETCH_TIME << TIM_RAND_SLAVE_STRETCH_SHIFT);
writel(val, iproc_i2c->base + TIM_CFG_OFFSET);
/* Configure the slave address */
val = readl(iproc_i2c->base + S_CFG_SMBUS_ADDR_OFFSET);
val |= BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
val &= ~(S_CFG_NIC_SMB_ADDR3_MASK << S_CFG_NIC_SMB_ADDR3_SHIFT);
val |= (iproc_i2c->slave->addr << S_CFG_NIC_SMB_ADDR3_SHIFT);
writel(val, iproc_i2c->base + S_CFG_SMBUS_ADDR_OFFSET);
/* clear all pending slave interrupts */
writel(ISR_MASK_SLAVE, iproc_i2c->base + IS_OFFSET);
/* Enable interrupt register for any READ event */
val = BIT(IE_S_RD_EVENT_SHIFT);
/* Enable interrupt register to indicate a valid byte in receive fifo */
val |= BIT(IE_S_RX_EVENT_SHIFT);
/* Enable interrupt register for the Slave BUSY command */
val |= BIT(IE_S_START_BUSY_SHIFT);
writel(val, iproc_i2c->base + IE_OFFSET);
iproc_i2c->xfer_dir = I2C_SLAVE_DIR_NONE;
}
static void bcm_iproc_i2c_check_slave_status(
struct bcm_iproc_i2c_dev *iproc_i2c)
{
u32 val;
val = readl(iproc_i2c->base + S_CMD_OFFSET);
val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
if (val == S_CMD_STATUS_TIMEOUT) {
dev_err(iproc_i2c->device, "slave random stretch time timeout\n");
/* re-initialize i2c for recovery */
bcm_iproc_i2c_enable_disable(iproc_i2c, false);
bcm_iproc_i2c_slave_init(iproc_i2c, true);
bcm_iproc_i2c_enable_disable(iproc_i2c, true);
}
}
static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
u32 status)
{
u8 value;
u32 val;
u32 rd_status;
u32 tmp;
/* Start of transaction. check address and populate the direction */
if (iproc_i2c->xfer_dir == I2C_SLAVE_DIR_NONE) {
tmp = readl(iproc_i2c->base + S_RX_OFFSET);
rd_status = (tmp >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
/* This condition checks whether the request is a new request */
if (((rd_status == I2C_SLAVE_RX_START) &&
(status & BIT(IS_S_RX_EVENT_SHIFT))) ||
((rd_status == I2C_SLAVE_RX_END) &&
(status & BIT(IS_S_RD_EVENT_SHIFT)))) {
/* Last bit is W/R bit.
* If 1 then its a read request(by master).
*/
iproc_i2c->xfer_dir = tmp & SLAVE_READ_WRITE_BIT_MASK;
if (iproc_i2c->xfer_dir == I2C_SLAVE_DIR_WRITE)
i2c_slave_event(iproc_i2c->slave,
I2C_SLAVE_READ_REQUESTED, &value);
else
i2c_slave_event(iproc_i2c->slave,
I2C_SLAVE_WRITE_REQUESTED, &value);
}
}
/* read request from master */
if ((status & BIT(IS_S_RD_EVENT_SHIFT)) &&
(iproc_i2c->xfer_dir == I2C_SLAVE_DIR_WRITE)) {
i2c_slave_event(iproc_i2c->slave,
I2C_SLAVE_READ_PROCESSED, &value);
writel(value, iproc_i2c->base + S_TX_OFFSET);
val = BIT(S_CMD_START_BUSY_SHIFT);
writel(val, iproc_i2c->base + S_CMD_OFFSET);
}
/* write request from master */
if ((status & BIT(IS_S_RX_EVENT_SHIFT)) &&
(iproc_i2c->xfer_dir == I2C_SLAVE_DIR_READ)) {
val = readl(iproc_i2c->base + S_RX_OFFSET);
/* Its a write request by Master to Slave.
* We read data present in receive FIFO
*/
value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
i2c_slave_event(iproc_i2c->slave,
I2C_SLAVE_WRITE_RECEIVED, &value);
/* check the status for the last byte of the transaction */
rd_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
if (rd_status == I2C_SLAVE_RX_END)
iproc_i2c->xfer_dir = I2C_SLAVE_DIR_NONE;
dev_dbg(iproc_i2c->device, "\nread value = 0x%x\n", value);
}
/* Stop */
if (status & BIT(IS_S_START_BUSY_SHIFT)) {
i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
iproc_i2c->xfer_dir = I2C_SLAVE_DIR_NONE;
}
/* clear interrupt status */
writel(status, iproc_i2c->base + IS_OFFSET);
bcm_iproc_i2c_check_slave_status(iproc_i2c);
return true;
}
static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c)
{
struct i2c_msg *msg = iproc_i2c->msg;
@ -140,6 +375,18 @@ static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
u32 status = readl(iproc_i2c->base + IS_OFFSET);
u32 tmp;
bool ret;
u32 sl_status = status & ISR_MASK_SLAVE;
if (sl_status) {
ret = bcm_iproc_i2c_slave_isr(iproc_i2c, sl_status);
if (ret)
return IRQ_HANDLED;
else
return IRQ_NONE;
}
status &= ISR_MASK;
if (!status)
@ -222,22 +469,25 @@ static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
/* put controller in reset */
val = readl(iproc_i2c->base + CFG_OFFSET);
val |= 1 << CFG_RESET_SHIFT;
val &= ~(1 << CFG_EN_SHIFT);
val |= BIT(CFG_RESET_SHIFT);
val &= ~(BIT(CFG_EN_SHIFT));
writel(val, iproc_i2c->base + CFG_OFFSET);
/* wait 100 usec per spec */
udelay(100);
/* bring controller out of reset */
val &= ~(1 << CFG_RESET_SHIFT);
val &= ~(BIT(CFG_RESET_SHIFT));
writel(val, iproc_i2c->base + CFG_OFFSET);
/* flush TX/RX FIFOs and set RX FIFO threshold to zero */
val = (1 << M_FIFO_RX_FLUSH_SHIFT) | (1 << M_FIFO_TX_FLUSH_SHIFT);
val = (BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT));
writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET);
/* disable all interrupts */
writel(0, iproc_i2c->base + IE_OFFSET);
val = readl(iproc_i2c->base + IE_OFFSET);
val &= ~(IE_M_ALL_INTERRUPT_MASK <<
IE_M_ALL_INTERRUPT_SHIFT);
writel(val, iproc_i2c->base + IE_OFFSET);
/* clear all pending interrupts */
writel(0xffffffff, iproc_i2c->base + IS_OFFSET);
@ -440,12 +690,14 @@ static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SLAVE;
}
static const struct i2c_algorithm bcm_iproc_algo = {
.master_xfer = bcm_iproc_i2c_xfer,
.functionality = bcm_iproc_i2c_functionality,
.reg_slave = bcm_iproc_i2c_reg_slave,
.unreg_slave = bcm_iproc_i2c_unreg_slave,
};
static struct i2c_adapter_quirks bcm_iproc_i2c_quirks = {
@ -610,6 +862,46 @@ static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
#define BCM_IPROC_I2C_PM_OPS NULL
#endif /* CONFIG_PM_SLEEP */
static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave)
{
struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
if (iproc_i2c->slave)
return -EBUSY;
if (slave->flags & I2C_CLIENT_TEN)
return -EAFNOSUPPORT;
iproc_i2c->slave = slave;
bcm_iproc_i2c_slave_init(iproc_i2c, false);
return 0;
}
static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
{
u32 tmp;
struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
if (!iproc_i2c->slave)
return -EINVAL;
iproc_i2c->slave = NULL;
/* disable all slave interrupts */
tmp = readl(iproc_i2c->base + IE_OFFSET);
tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
IE_S_ALL_INTERRUPT_SHIFT);
writel(tmp, iproc_i2c->base + IE_OFFSET);
/* Erase the slave address programmed */
tmp = readl(iproc_i2c->base + S_CFG_SMBUS_ADDR_OFFSET);
tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
writel(tmp, iproc_i2c->base + S_CFG_SMBUS_ADDR_OFFSET);
return 0;
}
static const struct of_device_id bcm_iproc_i2c_of_match[] = {
{ .compatible = "brcm,iproc-i2c" },
{ /* sentinel */ }