[U-Boot] [PATCH 4/4] i2c: muxes: Add support for TI PCA954X mux

[Michal Simek]

Add support for common TI i2c mux which is available on ZynqMP zcu102
board.
DM i2c mux core code is selecting/deselecting bus before/after
every command is performed that's why only one channel is active at a
time. That's also the reason why deselect is just disable all available
channels.

Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---

 drivers/i2c/muxes/Kconfig   |  7 ++++
 drivers/i2c/muxes/Makefile  |  1 +
 drivers/i2c/muxes/pca954x.c | 79 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 87 insertions(+)
 create mode 100644 drivers/i2c/muxes/pca954x.c

diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index f959d9de9e8b..e16b902f9611 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -24,3 +24,10 @@ config I2C_ARB_GPIO_CHALLENGE
 	  I2C multimaster arbitration scheme using GPIOs and a challenge &
 	  response mechanism where masters have to claim the bus by asserting
 	  a GPIO.
+
+config I2C_MUX_PCA954X
+        tristate "TI PCA954x I2C Mux/switches"
+        depends on I2C_MUX
+        help
+          If you say yes here you get support for the TI PCA954x
+          I2C mux/switch devices.
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index 47c1240d7e9e..fb2d67ec9a97 100644
--- a/drivers/i2c/muxes/Makefile
+++ b/drivers/i2c/muxes/Makefile
@@ -5,3 +5,4 @@
 #
 obj-$(CONFIG_I2C_ARB_GPIO_CHALLENGE) += i2c-arb-gpio-challenge.o
 obj-$(CONFIG_$(SPL_)I2C_MUX) += i2c-mux-uclass.o
+obj-$(CONFIG_I2C_MUX_PCA954X) += pca954x.o
diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
new file mode 100644
index 000000000000..206581d3d908
--- /dev/null
+++ b/drivers/i2c/muxes/pca954x.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2015 - 2016 Xilinx, Inc.
+ * Written by Michal Simek
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <i2c.h>
+#include <asm/gpio.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct pca95xx_priv {
+	u32 addr;
+	u32 width;
+};
+
+static int pca95xx_deselect(struct udevice *mux, struct udevice *bus,
+			    uint channel)
+{
+	struct pca95xx_priv *priv = dev_get_priv(mux);
+	uchar byte = 0;
+
+	return dm_i2c_write(mux, priv->addr, &byte, 1);
+}
+
+static int pca95xx_select(struct udevice *mux, struct udevice *bus,
+			  uint channel)
+{
+	struct pca95xx_priv *priv = dev_get_priv(mux);
+	uchar byte = 1 << channel;
+
+	return dm_i2c_write(mux, priv->addr, &byte, 1);
+}
+
+static const struct i2c_mux_ops pca95xx_ops = {
+	.select = pca95xx_select,
+	.deselect = pca95xx_deselect,
+};
+
+static const struct udevice_id pca95xx_ids[] = {
+	{ .compatible = "nxp,pca9548", .data = (ulong)8 },
+	{ .compatible = "nxp,pca9544", .data = (ulong)4 },
+	{ }
+};
+
+static int pca95xx_ofdata_to_platdata(struct udevice *dev)
+{
+	struct pca95xx_priv *priv = dev_get_priv(dev);
+
+	priv->addr = dev_get_addr(dev);
+	if (!priv->addr) {
+		debug("MUX not found\n");
+		return -ENOSYS;
+	}
+	priv->width = dev_get_driver_data(dev);
+
+	if (!priv->width) {
+		debug("No I2C MUX width specified\n");
+		return -ENOSYS;
+	}
+
+	debug("Device %s at 0x%x with width %d\n",
+	      dev->name, priv->addr, priv->width);
+
+	return 0;
+}
+
+U_BOOT_DRIVER(pca95xx) = {
+	.name = "pca95xx",
+	.id = UCLASS_I2C_MUX,
+	.of_match = pca95xx_ids,
+	.ops = &pca95xx_ops,
+	.ofdata_to_platdata = pca95xx_ofdata_to_platdata,
+	.priv_auto_alloc_size = sizeof(struct pca95xx_priv),
+};
-- 
1.9.1