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 ---
Changes in v2: - use fdtdec_get_int() for getting i2c address instead of dev_get_addr() which is designed for MMIO accesses and requires non zero size cells. - Change returned error code - Simon - Use 954x instead of 954X and 95xx - Michal - Extend Kconfig description - Simon - Add comments to private structure - Simon
Simon, Heiko: Feel free to comment this version and reject your tag.
--- drivers/i2c/muxes/Kconfig | 10 ++++++ drivers/i2c/muxes/Makefile | 1 + drivers/i2c/muxes/pca954x.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 90 insertions(+) create mode 100644 drivers/i2c/muxes/pca954x.c
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig index f959d9de9e8b..48900ed2afc5 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 47c1240d7e9e..0811add4216e 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..7e0d2da4d605 --- /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), +};