On 06/25/2018 09:38 PM, Wolfram Sang wrote:

On Wed, Jun 13, 2018 at 02:36:17PM -0500, Eddie James wrote:

quoted

Execute I2C transfers from the FSI-attached I2C master. Use polling
instead of interrupts as we have no hardware IRQ over FSI.

Signed-off-by: Eddie James <redacted>
---
  drivers/i2c/busses/i2c-fsi.c | 195 ++++++++++++++++++++++++++++++++++++++++++-
  1 file changed, 193 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c
index 4611a0b..8c0a6cb 100644
--- a/drivers/i2c/busses/i2c-fsi.c
+++ b/drivers/i2c/busses/i2c-fsi.c

@@ -155,6 +155,7 @@ struct fsi_i2c_port {
  	struct i2c_adapter	adapter;
  	struct fsi_i2c_master	*master;
  	u16			port;
+	u16			xfrd;
  };
  
  static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg,

@@ -230,6 +231,99 @@ static int fsi_i2c_set_port(struct fsi_i2c_port *port)
  	return fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, &dummy);
  }
  
+static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg,
+			 bool stop)
+{
+	struct fsi_i2c_master *i2c = port->master;
+	u32 cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR;
+
+	port->xfrd = 0;
+
+	if (msg->flags & I2C_M_RD)
+		cmd |= I2C_CMD_READ;

Since you support MANGLING, I'd think you can easily support
I2C_M_REV_DIR_ADDR here, too?

Hm, I don't really understand the purpose of that flag. From the docs:

This toggles the Rd/Wr flag. That is, if you want to do a write, but
     need to emit an Rd instead of a Wr, or vice versa, you set this
     flag. For example:
S Addr Rd [A] Data [A] Data [A] ... [A] Data [A] P

I don't think our hardware supports this type of operation.

Thanks,
Eddie