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authorMichal Simek <michal.simek@xilinx.com>2016-04-25 10:50:42 +0200
committerHeiko Schocher <hs@denx.de>2016-05-17 08:28:50 +0200
commitd79ac324789839b4b10b37e2ff64dd9e4a92441e (patch)
tree901b815c4d8ccbc84c5b42f463e72a087414def1 /drivers/i2c/muxes
parentad72e7622bd587dc798fbac0351b558fb18caa97 (diff)
i2c: muxes: Add support for TI PCA954X mux
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@xilinx.com> Reviewed-by: Heiko Schocher <hs@denx.de> Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/i2c/muxes')
-rw-r--r--drivers/i2c/muxes/Kconfig10
-rw-r--r--drivers/i2c/muxes/Makefile1
-rw-r--r--drivers/i2c/muxes/pca954x.c79
3 files changed, 90 insertions, 0 deletions
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index f959d9de9e..48900ed2af 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -24,3 +24,13 @@ 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. It is x width I2C multiplexer which enables to
+ paritioning I2C bus and connect multiple devices with the same address
+ to the same I2C controller where driver handles proper routing to
+ target i2c device. PCA9544 and PCA9548 are supported.
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index 47c1240d7e..0811add421 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 0000000000..7e0d2da4d6
--- /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 pca954x_priv {
+ u32 addr; /* I2C mux address */
+ u32 width; /* I2C mux width - number of busses */
+};
+
+static int pca954x_deselect(struct udevice *mux, struct udevice *bus,
+ uint channel)
+{
+ struct pca954x_priv *priv = dev_get_priv(mux);
+ uchar byte = 0;
+
+ return dm_i2c_write(mux, priv->addr, &byte, 1);
+}
+
+static int pca954x_select(struct udevice *mux, struct udevice *bus,
+ uint channel)
+{
+ struct pca954x_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 pca954x_ops = {
+ .select = pca954x_select,
+ .deselect = pca954x_deselect,
+};
+
+static const struct udevice_id pca954x_ids[] = {
+ { .compatible = "nxp,pca9548", .data = (ulong)8 },
+ { .compatible = "nxp,pca9544", .data = (ulong)4 },
+ { }
+};
+
+static int pca954x_ofdata_to_platdata(struct udevice *dev)
+{
+ struct pca954x_priv *priv = dev_get_priv(dev);
+
+ priv->addr = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "reg", 0);
+ if (!priv->addr) {
+ debug("MUX not found\n");
+ return -ENODEV;
+ }
+ priv->width = dev_get_driver_data(dev);
+
+ if (!priv->width) {
+ debug("No I2C MUX width specified\n");
+ return -EINVAL;
+ }
+
+ debug("Device %s at 0x%x with width %d\n",
+ dev->name, priv->addr, priv->width);
+
+ return 0;
+}
+
+U_BOOT_DRIVER(pca954x) = {
+ .name = "pca954x",
+ .id = UCLASS_I2C_MUX,
+ .of_match = pca954x_ids,
+ .ops = &pca954x_ops,
+ .ofdata_to_platdata = pca954x_ofdata_to_platdata,
+ .priv_auto_alloc_size = sizeof(struct pca954x_priv),
+};