|
|
@@ -0,0 +1,220 @@
|
|
|
+/*
|
|
|
+ * drivers/i2c/muxes/i2c-mux-mlxcpld.c
|
|
|
+ * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
|
|
|
+ * Copyright (c) 2016 Michael Shych <michaels@mellanox.com>
|
|
|
+ *
|
|
|
+ * Redistribution and use in source and binary forms, with or without
|
|
|
+ * modification, are permitted provided that the following conditions are met:
|
|
|
+ *
|
|
|
+ * 1. Redistributions of source code must retain the above copyright
|
|
|
+ * notice, this list of conditions and the following disclaimer.
|
|
|
+ * 2. Redistributions in binary form must reproduce the above copyright
|
|
|
+ * notice, this list of conditions and the following disclaimer in the
|
|
|
+ * documentation and/or other materials provided with the distribution.
|
|
|
+ * 3. Neither the names of the copyright holders nor the names of its
|
|
|
+ * contributors may be used to endorse or promote products derived from
|
|
|
+ * this software without specific prior written permission.
|
|
|
+ *
|
|
|
+ * Alternatively, this software may be distributed under the terms of the
|
|
|
+ * GNU General Public License ("GPL") version 2 as published by the Free
|
|
|
+ * Software Foundation.
|
|
|
+ *
|
|
|
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
|
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
|
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
|
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
|
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
|
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
|
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
|
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
|
+ * POSSIBILITY OF SUCH DAMAGE.
|
|
|
+ */
|
|
|
+
|
|
|
+#include <linux/device.h>
|
|
|
+#include <linux/i2c.h>
|
|
|
+#include <linux/i2c-mux.h>
|
|
|
+#include <linux/io.h>
|
|
|
+#include <linux/init.h>
|
|
|
+#include <linux/module.h>
|
|
|
+#include <linux/platform_device.h>
|
|
|
+#include <linux/slab.h>
|
|
|
+#include <linux/version.h>
|
|
|
+#include <linux/i2c/mlxcpld.h>
|
|
|
+
|
|
|
+#define CPLD_MUX_MAX_NCHANS 8
|
|
|
+
|
|
|
+/* mlxcpld_mux - mux control structure:
|
|
|
+ * @last_chan - last register value
|
|
|
+ * @client - I2C device client
|
|
|
+ */
|
|
|
+struct mlxcpld_mux {
|
|
|
+ u8 last_chan;
|
|
|
+ struct i2c_client *client;
|
|
|
+};
|
|
|
+
|
|
|
+/* MUX logic description.
|
|
|
+ * Driver can support different mux control logic, according to CPLD
|
|
|
+ * implementation.
|
|
|
+ *
|
|
|
+ * Connectivity schema.
|
|
|
+ *
|
|
|
+ * i2c-mlxcpld Digital Analog
|
|
|
+ * driver
|
|
|
+ * *--------* * -> mux1 (virt bus2) -> mux -> |
|
|
|
+ * | I2CLPC | i2c physical * -> mux2 (virt bus3) -> mux -> |
|
|
|
+ * | bridge | bus 1 *---------* |
|
|
|
+ * | logic |---------------------> * mux reg * |
|
|
|
+ * | in CPLD| *---------* |
|
|
|
+ * *--------* i2c-mux-mlxpcld ^ * -> muxn (virt busn) -> mux -> |
|
|
|
+ * | driver | |
|
|
|
+ * | *---------------* | Devices
|
|
|
+ * | * CPLD (i2c bus)* select |
|
|
|
+ * | * registers for *--------*
|
|
|
+ * | * mux selection * deselect
|
|
|
+ * | *---------------*
|
|
|
+ * | |
|
|
|
+ * <--------> <----------->
|
|
|
+ * i2c cntrl Board cntrl reg
|
|
|
+ * reg space space (mux select,
|
|
|
+ * IO, LED, WD, info)
|
|
|
+ *
|
|
|
+ */
|
|
|
+
|
|
|
+static const struct i2c_device_id mlxcpld_mux_id[] = {
|
|
|
+ { "mlxcpld_mux_module", 0 },
|
|
|
+ { }
|
|
|
+};
|
|
|
+MODULE_DEVICE_TABLE(i2c, mlxcpld_mux_id);
|
|
|
+
|
|
|
+/* Write to mux register. Don't use i2c_transfer() and i2c_smbus_xfer()
|
|
|
+ * for this as they will try to lock adapter a second time.
|
|
|
+ */
|
|
|
+static int mlxcpld_mux_reg_write(struct i2c_adapter *adap,
|
|
|
+ struct i2c_client *client, u8 val)
|
|
|
+{
|
|
|
+ struct mlxcpld_mux_plat_data *pdata = dev_get_platdata(&client->dev);
|
|
|
+
|
|
|
+ if (adap->algo->master_xfer) {
|
|
|
+ struct i2c_msg msg;
|
|
|
+ u8 msgbuf[] = {pdata->sel_reg_addr, val};
|
|
|
+
|
|
|
+ msg.addr = client->addr;
|
|
|
+ msg.flags = 0;
|
|
|
+ msg.len = 2;
|
|
|
+ msg.buf = msgbuf;
|
|
|
+ return __i2c_transfer(adap, &msg, 1);
|
|
|
+ } else if (adap->algo->smbus_xfer) {
|
|
|
+ union i2c_smbus_data data;
|
|
|
+
|
|
|
+ data.byte = val;
|
|
|
+ return adap->algo->smbus_xfer(adap, client->addr,
|
|
|
+ client->flags, I2C_SMBUS_WRITE,
|
|
|
+ pdata->sel_reg_addr,
|
|
|
+ I2C_SMBUS_BYTE_DATA, &data);
|
|
|
+ } else
|
|
|
+ return -ENODEV;
|
|
|
+}
|
|
|
+
|
|
|
+static int mlxcpld_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)
|
|
|
+{
|
|
|
+ struct mlxcpld_mux *data = i2c_mux_priv(muxc);
|
|
|
+ struct i2c_client *client = data->client;
|
|
|
+ u8 regval = chan + 1;
|
|
|
+ int err = 0;
|
|
|
+
|
|
|
+ /* Only select the channel if its different from the last channel */
|
|
|
+ if (data->last_chan != regval) {
|
|
|
+ err = mlxcpld_mux_reg_write(muxc->parent, client, regval);
|
|
|
+ if (err)
|
|
|
+ data->last_chan = 0;
|
|
|
+ else
|
|
|
+ data->last_chan = regval;
|
|
|
+ }
|
|
|
+
|
|
|
+ return err;
|
|
|
+}
|
|
|
+
|
|
|
+static int mlxcpld_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
|
|
|
+{
|
|
|
+ struct mlxcpld_mux *data = i2c_mux_priv(muxc);
|
|
|
+ struct i2c_client *client = data->client;
|
|
|
+
|
|
|
+ /* Deselect active channel */
|
|
|
+ data->last_chan = 0;
|
|
|
+
|
|
|
+ return mlxcpld_mux_reg_write(muxc->parent, client, data->last_chan);
|
|
|
+}
|
|
|
+
|
|
|
+/* Probe/reomove functions */
|
|
|
+static int mlxcpld_mux_probe(struct i2c_client *client,
|
|
|
+ const struct i2c_device_id *id)
|
|
|
+{
|
|
|
+ struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
|
|
|
+ struct mlxcpld_mux_plat_data *pdata = dev_get_platdata(&client->dev);
|
|
|
+ struct i2c_mux_core *muxc;
|
|
|
+ int num, force;
|
|
|
+ struct mlxcpld_mux *data;
|
|
|
+ int err;
|
|
|
+
|
|
|
+ if (!pdata)
|
|
|
+ return -EINVAL;
|
|
|
+
|
|
|
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
|
|
|
+ return -ENODEV;
|
|
|
+
|
|
|
+ muxc = i2c_mux_alloc(adap, &client->dev, CPLD_MUX_MAX_NCHANS,
|
|
|
+ sizeof(*data), 0, mlxcpld_mux_select_chan,
|
|
|
+ mlxcpld_mux_deselect);
|
|
|
+ if (!muxc)
|
|
|
+ return -ENOMEM;
|
|
|
+
|
|
|
+ data = i2c_mux_priv(muxc);
|
|
|
+ i2c_set_clientdata(client, muxc);
|
|
|
+ data->client = client;
|
|
|
+ data->last_chan = 0; /* force the first selection */
|
|
|
+
|
|
|
+ /* Create an adapter for each channel. */
|
|
|
+ for (num = 0; num < CPLD_MUX_MAX_NCHANS; num++) {
|
|
|
+ if (num >= pdata->num_adaps)
|
|
|
+ /* discard unconfigured channels */
|
|
|
+ break;
|
|
|
+
|
|
|
+ force = pdata->adap_ids[num];
|
|
|
+
|
|
|
+ err = i2c_mux_add_adapter(muxc, force, num, 0);
|
|
|
+ if (err)
|
|
|
+ goto virt_reg_failed;
|
|
|
+ }
|
|
|
+
|
|
|
+ return 0;
|
|
|
+
|
|
|
+virt_reg_failed:
|
|
|
+ i2c_mux_del_adapters(muxc);
|
|
|
+ return err;
|
|
|
+}
|
|
|
+
|
|
|
+static int mlxcpld_mux_remove(struct i2c_client *client)
|
|
|
+{
|
|
|
+ struct i2c_mux_core *muxc = i2c_get_clientdata(client);
|
|
|
+
|
|
|
+ i2c_mux_del_adapters(muxc);
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static struct i2c_driver mlxcpld_mux_driver = {
|
|
|
+ .driver = {
|
|
|
+ .name = "mlxcpld-mux",
|
|
|
+ },
|
|
|
+ .probe = mlxcpld_mux_probe,
|
|
|
+ .remove = mlxcpld_mux_remove,
|
|
|
+ .id_table = mlxcpld_mux_id,
|
|
|
+};
|
|
|
+
|
|
|
+module_i2c_driver(mlxcpld_mux_driver);
|
|
|
+
|
|
|
+MODULE_AUTHOR("Michael Shych (michaels@mellanox.com)");
|
|
|
+MODULE_DESCRIPTION("Mellanox I2C-CPLD-MUX driver");
|
|
|
+MODULE_LICENSE("Dual BSD/GPL");
|
|
|
+MODULE_ALIAS("platform:i2c-mux-mlxcpld");
|
Vadim Pasternak