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> --- v1->v2: Comments pointed out by Peter: - Remove data buffer allocation from 'mlxcpld_mux' structure, do it on stack instead. - Do not use array pdata.adap_ids[] in mlxcpld_mux_reg_write() for channel assignment. - Return back 'regval' variable, used for channel assignment in mlxcpld_mux_select_chan(). - Fix functionality validation in mlxcpld_mux_probe(). - Fix comment for 'reg_size' field in mlxcpld_mux_plat_data' structure. Added by Vadim: - Change type of register select address to '__be16' to align with type in assignment in cpu_to_be16(). --- drivers/i2c/muxes/i2c-mux-mlxcpld.c | 54 ++++++++++++++++++++++++++++------- include/linux/platform_data/mlxcpld.h | 2 ++ 2 files changed, 46 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/muxes/i2c-mux-mlxcpld.c b/drivers/i2c/muxes/i2c-mux-mlxcpld.c index b53f1479272d..4848dd4ff41a 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_reg_addr: mux select/deselect register address */ struct mlxcpld_mux { u8 last_chan; struct i2c_client *client; struct mlxcpld_mux_plat_data pdata; + __be16 sel_reg_addr; }; /* MUX logic description. @@ -60,24 +62,43 @@ 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; + u8 buf[3]; + + 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: + memcpy(buf, &mux->sel_reg_addr, 2); + buf[2] = chan; + msg.addr = client->addr; + msg.buf = 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; + u8 regval = chan; int err = 0; + if (mux->pdata.reg_size == 1) + regval += 1; + /* Only select the channel if its different from the last channel */ - if (mux->last_chan != regval) { + if (mux->last_chan != chan) { err = mlxcpld_mux_reg_write(muxc->parent, mux, regval); mux->last_chan = err < 0 ? 0 : regval; } @@ -103,13 +124,24 @@ static int mlxcpld_mux_probe(struct platform_device *pdev) struct i2c_mux_core *muxc; int num, force; struct mlxcpld_mux *data; + 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_I2C; + 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 +154,8 @@ 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. */ + data->sel_reg_addr = cpu_to_be16(pdata->sel_reg_addr); 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..9cb2c3d8293e 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 */ 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