Extend driver to allow I2C routing control through CPLD devices with
word address space. Till now only CPLD devices with byte address space
have been supported.
Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxx>
Reviewed-by: Michael Shych <michaelsh@xxxxxxxxxx>
---
drivers/i2c/muxes/i2c-mux-mlxcpld.c | 57 +++++++++++++++++++++++++++--------
include/linux/platform_data/mlxcpld.h | 2 ++
2 files changed, 47 insertions(+), 12 deletions(-)
diff --git a/drivers/i2c/muxes/i2c-mux-mlxcpld.c b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
index 6bb8caecf8e8..c76180919fc3 100644
--- a/drivers/i2c/muxes/i2c-mux-mlxcpld.c
+++ b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
@@ -21,11 +21,13 @@
* @last_chan - last register value
* @client - I2C device client
* @pdata: platform data
+ * @sel_buf: I2C message buffer for mux select 16 bits transactions
*/
struct mlxcpld_mux {
u8 last_chan;
struct i2c_client *client;
struct mlxcpld_mux_plat_data pdata;
+ u8 sel_buf[3];
};
/* MUX logic description.
@@ -60,26 +62,42 @@ struct mlxcpld_mux {
* for this as they will try to lock adapter a second time.
*/
static int mlxcpld_mux_reg_write(struct i2c_adapter *adap,
- struct mlxcpld_mux *mux, u8 val)
+ struct mlxcpld_mux *mux, int chan)
{
struct i2c_client *client = mux->client;
- union i2c_smbus_data data = { .byte = val };
-
- return __i2c_smbus_xfer(adap, client->addr, client->flags,
- I2C_SMBUS_WRITE, mux->pdata.sel_reg_addr,
- I2C_SMBUS_BYTE_DATA, &data);
+ union i2c_smbus_data data;
+ struct i2c_msg msg;
+
+ switch (mux->pdata.reg_size) {
+ case 1:
+ data.byte = (chan < 0) ? 0 : chan;
+ return __i2c_smbus_xfer(adap, client->addr, client->flags,
+ I2C_SMBUS_WRITE,
+ mux->pdata.sel_reg_addr,
+ I2C_SMBUS_BYTE_DATA, &data);
+ case 2:
+ mux->sel_buf[mux->pdata.reg_size] = (chan < 0) ? 0 :
+ mux->pdata.adap_ids[chan];
+ msg.addr = client->addr;
+ msg.buf = mux->sel_buf;
+ msg.len = mux->pdata.reg_size + 1;
+ msg.flags = 0;
+ return __i2c_transfer(adap, &msg, 1);
+ default:
+ return -EINVAL;
+ }
}
static int mlxcpld_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)
{
struct mlxcpld_mux *mux = i2c_mux_priv(muxc);
- u8 regval = chan + 1;
int err = 0;
/* Only select the channel if its different from the last channel */
- if (mux->last_chan != regval) {
- err = mlxcpld_mux_reg_write(muxc->parent, mux, regval);
- mux->last_chan = err < 0 ? 0 : regval;
+ chan++;
+ if (mux->last_chan != chan) {
+ err = mlxcpld_mux_reg_write(muxc->parent, mux, chan);
+ mux->last_chan = err < 0 ? 0 : chan;
}
return err;
@@ -103,13 +121,26 @@ static int mlxcpld_mux_probe(struct platform_device *pdev)
struct i2c_mux_core *muxc;
int num, force;
struct mlxcpld_mux *data;
+ u16 sel_reg_addr = 0;
+ u32 func;
int err;
if (!pdata)
return -EINVAL;
- if (!i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+ switch (pdata->reg_size) {
+ case 1:
+ func = I2C_FUNC_SMBUS_WRITE_BYTE_DATA;
+ break;
+ case 2:
+ func = I2C_FUNC_SMBUS_WRITE_WORD_DATA;
+ sel_reg_addr = cpu_to_be16(pdata->sel_reg_addr);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (!i2c_check_functionality(client->adapter, func))
return -ENODEV;
muxc = i2c_mux_alloc(client->adapter, &pdev->dev, CPLD_MUX_MAX_NCHANS,
@@ -122,6 +153,8 @@ static int mlxcpld_mux_probe(struct platform_device *pdev)
data = i2c_mux_priv(muxc);
data->client = client;
memcpy(&data->pdata, pdata, sizeof(*pdata));
+ /* Save mux select address for 16 bits transaction size. */
+ memcpy(data->sel_buf, &sel_reg_addr, 2);
data->last_chan = 0; /* force the first selection */
/* Create an adapter for each channel. */
diff --git a/include/linux/platform_data/mlxcpld.h b/include/linux/platform_data/mlxcpld.h
index e6c18bf017dd..da4f7e8f5721 100644
--- a/include/linux/platform_data/mlxcpld.h
+++ b/include/linux/platform_data/mlxcpld.h
@@ -14,11 +14,13 @@
* @adap_ids - adapter array
* @num_adaps - number of adapters
* @sel_reg_addr - mux select register offset in CPLD space
+ * @reg_size: register size in bytes (default 0 - 1 byte data, 1 - 2 bytes data
*/
struct mlxcpld_mux_plat_data {
int *adap_ids;
int num_adaps;
int sel_reg_addr;
+ u8 reg_size;
};
#endif /* _LINUX_I2C_MLXCPLD_H */
--
2.11.0
