2020-03-22 18:25:32

by Rayagonda Kokatanur

[permalink] [raw]
Subject: [PATCH v1 1/1] i2c: iproc: add support for SMBUS quick cmd

Add support for SMBUS quick command.

SMBUS quick command passes single bit of information to the
slave (target) device. Can be used to turn slave device on or off.

By default i2c_detect tool uses the smbus quick cmd to try and
detect devices. Without this support it will not detect some slaves.

Signed-off-by: Rayagonda Kokatanur <[email protected]>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index 30efb7913b2e..6a461e06e6dd 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -79,6 +79,7 @@
#define M_CMD_STATUS_RX_FIFO_FULL 0x6
#define M_CMD_PROTOCOL_SHIFT 9
#define M_CMD_PROTOCOL_MASK 0xf
+#define M_CMD_PROTOCOL_QUICK 0x0
#define M_CMD_PROTOCOL_BLK_WR 0x7
#define M_CMD_PROTOCOL_BLK_RD 0x8
#define M_CMD_PROTOCOL_PROCESS 0xa
@@ -765,7 +766,11 @@ static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
* number of bytes to read
*/
val = BIT(M_CMD_START_BUSY_SHIFT);
- if (msg->flags & I2C_M_RD) {
+
+ if (msg->len == 0) {
+ /* SMBUS QUICK Command (Read/Write) */
+ val |= (M_CMD_PROTOCOL_QUICK << M_CMD_PROTOCOL_SHIFT);
+ } else if (msg->flags & I2C_M_RD) {
u32 protocol;

iproc_i2c->rx_bytes = 0;
@@ -827,8 +832,7 @@ static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
{
u32 val;

- /* We do not support the SMBUS Quick command */
- val = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+ val = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;

if (adap->algo->reg_slave)
val |= I2C_FUNC_SLAVE;
--
2.17.1


2020-04-26 08:38:59

by Wolfram Sang

[permalink] [raw]
Subject: Re: [PATCH v1 1/1] i2c: iproc: add support for SMBUS quick cmd

On Sun, Mar 22, 2020 at 11:53:22PM +0530, Rayagonda Kokatanur wrote:
> Add support for SMBUS quick command.
>
> SMBUS quick command passes single bit of information to the
> slave (target) device. Can be used to turn slave device on or off.
>
> By default i2c_detect tool uses the smbus quick cmd to try and
> detect devices. Without this support it will not detect some slaves.
>
> Signed-off-by: Rayagonda Kokatanur <[email protected]>

Applied to for-next, thanks!


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