Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 194 insertions, 0 deletions

diff --git a/drivers/i2c/muxes/i2c-mux-mlxcpld.c b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
new file mode 100644
index 000000000..1a879f6a3
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/*
+ * Mellanox i2c mux driver
+ *
+ * Copyright (C) 2016-2020 Mellanox Technologies
+ */
+
+#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_data/mlxcpld.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* mlxcpld_mux - mux control structure:
+ * @last_val - last selected register value or -1 if mux deselected
+ * @client - I2C device client
+ * @pdata: platform data
+ */
+struct mlxcpld_mux {
+	int last_val;
+	struct i2c_client *client;
+	struct mlxcpld_mux_plat_data pdata;
+};
+
+/* 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)
+ *
+ */
+
+/* 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 mlxcpld_mux *mux, u32 val)
+{
+	struct i2c_client *client = mux->client;
+	union i2c_smbus_data data;
+	struct i2c_msg msg;
+	u8 buf[3];
+
+	switch (mux->pdata.reg_size) {
+	case 1:
+		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);
+	case 2:
+		buf[0] = mux->pdata.sel_reg_addr >> 8;
+		buf[1] = mux->pdata.sel_reg_addr;
+		buf[2] = val;
+		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);
+	u32 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_val != regval) {
+		err = mlxcpld_mux_reg_write(muxc->parent, mux, regval);
+		mux->last_val = err < 0 ? -1 : regval;
+	}
+
+	return err;
+}
+
+static int mlxcpld_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+	struct mlxcpld_mux *mux = i2c_mux_priv(muxc);
+
+	/* Deselect active channel */
+	mux->last_val = -1;
+
+	return mlxcpld_mux_reg_write(muxc->parent, mux, 0);
+}
+
+/* Probe/reomove functions */
+static int mlxcpld_mux_probe(struct platform_device *pdev)
+{
+	struct mlxcpld_mux_plat_data *pdata = dev_get_platdata(&pdev->dev);
+	struct i2c_client *client = to_i2c_client(pdev->dev.parent);
+	struct i2c_mux_core *muxc;
+	struct mlxcpld_mux *data;
+	int num, err;
+	u32 func;
+
+	if (!pdata)
+		return -EINVAL;
+
+	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, pdata->num_adaps,
+			     sizeof(*data), 0, mlxcpld_mux_select_chan,
+			     mlxcpld_mux_deselect);
+	if (!muxc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, muxc);
+	data = i2c_mux_priv(muxc);
+	data->client = client;
+	memcpy(&data->pdata, pdata, sizeof(*pdata));
+	data->last_val = -1; /* force the first selection */
+
+	/* Create an adapter for each channel. */
+	for (num = 0; num < pdata->num_adaps; num++) {
+		err = i2c_mux_add_adapter(muxc, 0, pdata->chan_ids[num], 0);
+		if (err)
+			goto virt_reg_failed;
+	}
+
+	/* Notify caller when all channels' adapters are created. */
+	if (pdata->completion_notify)
+		pdata->completion_notify(pdata->handle, muxc->parent, muxc->adapter);
+
+	return 0;
+
+virt_reg_failed:
+	i2c_mux_del_adapters(muxc);
+	return err;
+}
+
+static int mlxcpld_mux_remove(struct platform_device *pdev)
+{
+	struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+	i2c_mux_del_adapters(muxc);
+	return 0;
+}
+
+static struct platform_driver mlxcpld_mux_driver = {
+	.driver = {
+		.name = "i2c-mux-mlxcpld",
+	},
+	.probe = mlxcpld_mux_probe,
+	.remove = mlxcpld_mux_remove,
+};
+
+module_platform_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");