Iproc supports PEC computation and checking in both Master
and Slave mode.
This patch adds support for PEC in slave mode.
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokata...@broadcom.com>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 50 +++++++++++++++++++++++++++---
1 file changed, 46 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c
b/drivers/i2c/busses/i2c-bcm-iproc.c
index 8a3c98866fb7..51c8b165bb5e 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -93,6 +93,7 @@
#define S_CMD_STATUS_MASK 0x07
#define S_CMD_STATUS_SUCCESS 0x0
#define S_CMD_STATUS_TIMEOUT 0x5
+#define S_CMD_PEC_SHIFT 8
#define IE_OFFSET 0x38
#define IE_M_RX_FIFO_FULL_SHIFT 31
@@ -138,7 +139,9 @@
#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_PEC_ERR_SHIFT 28
+#define S_RX_PEC_ERR_MASK 0x3
+#define S_RX_PEC_ERR 0x1
#define S_RX_DATA_SHIFT 0
#define S_RX_DATA_MASK 0xff
@@ -205,6 +208,8 @@ struct bcm_iproc_i2c_dev {
/* bytes that have been read */
unsigned int rx_bytes;
unsigned int thld_bytes;
+
+ bool en_s_pec;
};
/*
@@ -321,6 +326,24 @@ static void bcm_iproc_i2c_check_slave_status(
}
}
+static int bcm_iproc_smbus_check_slave_pec(struct bcm_iproc_i2c_dev *iproc_i2c,
+ u32 val)
+{
+ u8 err_status;
+ int ret = 0;
+
+ if (!iproc_i2c->en_s_pec)
+ return ret;
+
+ err_status = (u8)((val >> S_RX_PEC_ERR_SHIFT) & S_RX_PEC_ERR_MASK);
+ if (err_status == S_RX_PEC_ERR) {
+ dev_err(iproc_i2c->device, "Slave PEC error\n");
+ ret = -EBADMSG;
+ }
+
+ return ret;
+}
+
static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
u32 status)
{
@@ -347,6 +370,8 @@ static bool bcm_iproc_i2c_slave_isr(struct
bcm_iproc_i2c_dev *iproc_i2c,
iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
val = BIT(S_CMD_START_BUSY_SHIFT);
+ if (iproc_i2c->en_s_pec)
+ val |= BIT(S_CMD_PEC_SHIFT);
iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
/*
@@ -361,9 +386,19 @@ static bool bcm_iproc_i2c_slave_isr(struct
bcm_iproc_i2c_dev *iproc_i2c,
value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
i2c_slave_event(iproc_i2c->slave,
I2C_SLAVE_WRITE_RECEIVED, &value);
- if (rx_status == I2C_SLAVE_RX_END)
- i2c_slave_event(iproc_i2c->slave,
- I2C_SLAVE_STOP, &value);
+ if (rx_status == I2C_SLAVE_RX_END) {
+ int ret;
+
+ ret = bcm_iproc_smbus_check_slave_pec(iproc_i2c,
+ val);
+ if (!ret)
+ i2c_slave_event(iproc_i2c->slave,
+ I2C_SLAVE_STOP, &value);
+ else
+ i2c_slave_event(iproc_i2c->slave,
+ I2C_SLAVE_PEC_ERR,
+ &value);
+ }
}
} else if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
/* Master read other than start */
@@ -372,6 +407,8 @@ static bool bcm_iproc_i2c_slave_isr(struct
bcm_iproc_i2c_dev *iproc_i2c,
iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
val = BIT(S_CMD_START_BUSY_SHIFT);
+ if (iproc_i2c->en_s_pec)
+ val |= BIT(S_CMD_PEC_SHIFT);
iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
}
@@ -1065,6 +1102,11 @@ static int bcm_iproc_i2c_reg_slave(struct i2c_client
*slave)
if (slave->flags & I2C_CLIENT_TEN)
return -EAFNOSUPPORT;
+ /* Enable partial slave HW PEC support if requested by the client */
+ iproc_i2c->en_s_pec = !!(slave->flags & I2C_CLIENT_PEC);
+ if (iproc_i2c->en_s_pec)
+ dev_info(iproc_i2c->device, "Enable PEC\n");
+
iproc_i2c->slave = slave;
bcm_iproc_i2c_slave_init(iproc_i2c, false);
return 0;
--
2.17.1
