[PATCH v2 2/3] soc: aspeed: Add LPC UART routing support

ChiaWei Wang chiawei_wang at aspeedtech.com
Thu Sep 2 12:25:09 AEST 2021


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Please ignore this one and check "[PATCH v2 2/3] soc: aspeed: Add UART routing support" instead.
Thanks.

Chiawei

> From: openbmc
> Sent: Thursday, September 2, 2021 10:18 AM
> 
> Add driver support for the LPC UART routing control. Users can perform
> runtime configuration of the RX muxes among the UART controllers and the
> UART IO pins.
> 
> A sysfs interface is also exported for the convenience of routing paths check
> and configuration.
> 
> Signed-off-by: Chia-Wei Wang <chiawei_wang at aspeedtech.com>
> ---
>  .../testing/sysfs-driver-aspeed-uart-routing  |  15 +
>  drivers/soc/aspeed/Kconfig                    |  10 +
>  drivers/soc/aspeed/Makefile                   |   9 +-
>  drivers/soc/aspeed/aspeed-uart-routing.c      | 601 ++++++++++++++++++
>  4 files changed, 631 insertions(+), 4 deletions(-)  create mode 100644
> Documentation/ABI/testing/sysfs-driver-aspeed-uart-routing
>  create mode 100644 drivers/soc/aspeed/aspeed-uart-routing.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-aspeed-uart-routing
> b/Documentation/ABI/testing/sysfs-driver-aspeed-uart-routing
> new file mode 100644
> index 000000000000..65f899f1f055
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-driver-aspeed-uart-routing
> @@ -0,0 +1,15 @@
> +What:		/sys/bus/platform/drivers/aspeed-uart-routing/*/uart*
> +Date:		September 2021
> +Contact:	Chia-Wei Wang <chiawei_wang at aspeedtech.com>
> +Description:	Selects the RX source of the UARTx device. The current
> +		selection will be marked with the '[]' brackets.
> +Users:		OpenBMC.  Proposed changes should be mailed to
> +		openbmc at lists.ozlabs.org
> +
> +What:		/sys/bus/platform/drivers/aspeed-uart-routing/*/io*
> +Date:		September 2021
> +Contact:	Chia-Wei Wang <chiawei_wang at aspeedtech.com>
> +Description:	Selects the RX source of IOx pins. The current selection
> +		will be marked with the '[]' brackets.
> +Users:		OpenBMC.  Proposed changes should be mailed to
> +		openbmc at lists.ozlabs.org
> diff --git a/drivers/soc/aspeed/Kconfig b/drivers/soc/aspeed/Kconfig index
> 243ca196e6ad..f579ee0b5afa 100644
> --- a/drivers/soc/aspeed/Kconfig
> +++ b/drivers/soc/aspeed/Kconfig
> @@ -24,6 +24,16 @@ config ASPEED_LPC_SNOOP
>  	  allows the BMC to listen on and save the data written by
>  	  the host to an arbitrary LPC I/O port.
> 
> +config ASPEED_UART_ROUTING
> +	tristate "ASPEED uart routing control"
> +	select REGMAP
> +	select MFD_SYSCON
> +	default ARCH_ASPEED
> +	help
> +	  Provides a driver to control the UART routing paths, allowing
> +	  users to perform runtime configuration of the RX muxes among
> +	  the UART controllers and I/O pins.
> +
>  config ASPEED_P2A_CTRL
>  	tristate "ASPEED P2A (VGA MMIO to BMC) bridge control"
>  	select REGMAP
> diff --git a/drivers/soc/aspeed/Makefile b/drivers/soc/aspeed/Makefile index
> fcab7192e1a4..b35d74592964 100644
> --- a/drivers/soc/aspeed/Makefile
> +++ b/drivers/soc/aspeed/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0-only
> -obj-$(CONFIG_ASPEED_LPC_CTRL)	+= aspeed-lpc-ctrl.o
> -obj-$(CONFIG_ASPEED_LPC_SNOOP)	+= aspeed-lpc-snoop.o
> -obj-$(CONFIG_ASPEED_P2A_CTRL)	+= aspeed-p2a-ctrl.o
> -obj-$(CONFIG_ASPEED_SOCINFO)	+= aspeed-socinfo.o
> +obj-$(CONFIG_ASPEED_LPC_CTRL)		+= aspeed-lpc-ctrl.o
> +obj-$(CONFIG_ASPEED_LPC_SNOOP)		+= aspeed-lpc-snoop.o
> +obj-$(CONFIG_ASPEED_UART_ROUTING)	+= aspeed-uart-routing.o
> +obj-$(CONFIG_ASPEED_P2A_CTRL)		+= aspeed-p2a-ctrl.o
> +obj-$(CONFIG_ASPEED_SOCINFO)		+= aspeed-socinfo.o
> diff --git a/drivers/soc/aspeed/aspeed-uart-routing.c
> b/drivers/soc/aspeed/aspeed-uart-routing.c
> new file mode 100644
> index 000000000000..eba6dfebb54f
> --- /dev/null
> +++ b/drivers/soc/aspeed/aspeed-uart-routing.c
> @@ -0,0 +1,601 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2018 Google LLC
> + * Copyright (c) 2021 Aspeed Technology Inc.
> + */
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_platform.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +#include <linux/platform_device.h>
> +
> +/* register offsets */
> +#define HICR9	0x98
> +#define HICRA	0x9c
> +
> +/* attributes options */
> +#define UART_ROUTING_IO1	"io1"
> +#define UART_ROUTING_IO2	"io2"
> +#define UART_ROUTING_IO3	"io3"
> +#define UART_ROUTING_IO4	"io4"
> +#define UART_ROUTING_IO5	"io5"
> +#define UART_ROUTING_IO6	"io6"
> +#define UART_ROUTING_IO10	"io10"
> +#define UART_ROUTING_UART1	"uart1"
> +#define UART_ROUTING_UART2	"uart2"
> +#define UART_ROUTING_UART3	"uart3"
> +#define UART_ROUTING_UART4	"uart4"
> +#define UART_ROUTING_UART5	"uart5"
> +#define UART_ROUTING_UART6	"uart6"
> +#define UART_ROUTING_UART10	"uart10"
> +#define UART_ROUTING_RES	"reserved"
> +
> +struct aspeed_uart_routing {
> +	struct regmap *map;
> +	struct attribute_group const *attr_grp; };
> +
> +struct aspeed_uart_routing_selector {
> +	struct device_attribute	dev_attr;
> +	uint8_t reg;
> +	uint8_t mask;
> +	uint8_t shift;
> +	const char *const options[];
> +};
> +
> +#define to_routing_selector(_dev_attr)					\
> +	container_of(_dev_attr, struct aspeed_uart_routing_selector, dev_attr)
> +
> +static ssize_t aspeed_uart_routing_show(struct device *dev,
> +					struct device_attribute *attr,
> +					char *buf);
> +
> +static ssize_t aspeed_uart_routing_store(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t count);
> +
> +#define ROUTING_ATTR(_name) {					\
> +	.attr = {.name = _name,					\
> +		 .mode = VERIFY_OCTAL_PERMISSIONS(0644) },	\
> +	.show = aspeed_uart_routing_show,			\
> +	.store = aspeed_uart_routing_store,			\
> +}
> +
> +/* routing selector for AST25xx */
> +static struct aspeed_uart_routing_selector ast2500_io6_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO6),
> +	.reg = HICR9,
> +	.shift = 8,
> +	.mask = 0xf,
> +	.options = {
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART5,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO5,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_uart5_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART5),
> +	.reg = HICRA,
> +	.shift = 28,
> +	.mask = 0xf,
> +	.options = {
> +		    UART_ROUTING_IO5,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_uart4_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART4),
> +	.reg = HICRA,
> +	.shift = 25,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +	},
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_uart3_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART3),
> +	.reg = HICRA,
> +	.shift = 22,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_uart2_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART2),
> +	.reg = HICRA,
> +	.shift = 19,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_uart1_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART1),
> +	.reg = HICRA,
> +	.shift = 16,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_io5_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO5),
> +	.reg = HICRA,
> +	.shift = 12,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART5,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_io4_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO4),
> +	.reg = HICRA,
> +	.shift = 9,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART5,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_io3_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO3),
> +	.reg = HICRA,
> +	.shift = 6,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART5,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_io2_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO2),
> +	.reg = HICRA,
> +	.shift = 3,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART5,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2500_io1_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO1),
> +	.reg = HICRA,
> +	.shift = 0,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART5,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO6,
> +		    NULL,
> +		    },
> +};
> +
> +static struct attribute *ast2500_uart_routing_attrs[] = {
> +	&ast2500_io6_sel.dev_attr.attr,
> +	&ast2500_uart5_sel.dev_attr.attr,
> +	&ast2500_uart4_sel.dev_attr.attr,
> +	&ast2500_uart3_sel.dev_attr.attr,
> +	&ast2500_uart2_sel.dev_attr.attr,
> +	&ast2500_uart1_sel.dev_attr.attr,
> +	&ast2500_io5_sel.dev_attr.attr,
> +	&ast2500_io4_sel.dev_attr.attr,
> +	&ast2500_io3_sel.dev_attr.attr,
> +	&ast2500_io2_sel.dev_attr.attr,
> +	&ast2500_io1_sel.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group ast2500_uart_routing_attr_group = {
> +	.attrs = ast2500_uart_routing_attrs,
> +};
> +
> +/* routing selector for AST26xx */
> +static struct aspeed_uart_routing_selector ast2600_uart10_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART10),
> +	.reg = HICR9,
> +	.shift = 12,
> +	.mask = 0xf,
> +	.options = {
> +		    UART_ROUTING_IO10,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +			UART_ROUTING_RES,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_io10_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO10),
> +	.reg = HICR9,
> +	.shift = 8,
> +	.mask = 0xf,
> +	.options = {
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +			UART_ROUTING_RES,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +			UART_ROUTING_RES,
> +		    UART_ROUTING_UART10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_uart4_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART4),
> +	.reg = HICRA,
> +	.shift = 25,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +	},
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_uart3_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART3),
> +	.reg = HICRA,
> +	.shift = 22,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_uart2_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART2),
> +	.reg = HICRA,
> +	.shift = 19,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_uart1_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART1),
> +	.reg = HICRA,
> +	.shift = 16,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_io4_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO4),
> +	.reg = HICRA,
> +	.shift = 9,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART10,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_io3_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO3),
> +	.reg = HICRA,
> +	.shift = 6,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART10,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_IO1,
> +		    UART_ROUTING_IO2,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_io2_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO2),
> +	.reg = HICRA,
> +	.shift = 3,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART10,
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct aspeed_uart_routing_selector ast2600_io1_sel = {
> +	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO1),
> +	.reg = HICRA,
> +	.shift = 0,
> +	.mask = 0x7,
> +	.options = {
> +		    UART_ROUTING_UART1,
> +		    UART_ROUTING_UART2,
> +		    UART_ROUTING_UART3,
> +		    UART_ROUTING_UART4,
> +		    UART_ROUTING_UART10,
> +		    UART_ROUTING_IO3,
> +		    UART_ROUTING_IO4,
> +		    UART_ROUTING_IO10,
> +		    NULL,
> +		    },
> +};
> +
> +static struct attribute *ast2600_uart_routing_attrs[] = {
> +	&ast2600_uart10_sel.dev_attr.attr,
> +	&ast2600_io10_sel.dev_attr.attr,
> +	&ast2600_uart4_sel.dev_attr.attr,
> +	&ast2600_uart3_sel.dev_attr.attr,
> +	&ast2600_uart2_sel.dev_attr.attr,
> +	&ast2600_uart1_sel.dev_attr.attr,
> +	&ast2600_io4_sel.dev_attr.attr,
> +	&ast2600_io3_sel.dev_attr.attr,
> +	&ast2600_io2_sel.dev_attr.attr,
> +	&ast2600_io1_sel.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group ast2600_uart_routing_attr_group = {
> +	.attrs = ast2600_uart_routing_attrs,
> +};
> +
> +static ssize_t aspeed_uart_routing_show(struct device *dev,
> +					struct device_attribute *attr,
> +					char *buf)
> +{
> +	struct aspeed_uart_routing *uart_routing = dev_get_drvdata(dev);
> +	struct aspeed_uart_routing_selector *sel = to_routing_selector(attr);
> +	int val, pos, len;
> +
> +	regmap_read(uart_routing->map, sel->reg, &val);
> +	val = (val >> sel->shift) & sel->mask;
> +
> +	len = 0;
> +	for (pos = 0; sel->options[pos] != NULL; ++pos) {
> +		if (pos == val)
> +			len += sysfs_emit_at(buf, len, "[%s] ", sel->options[pos]);
> +		else
> +			len += sysfs_emit_at(buf, len, "%s ", sel->options[pos]);
> +	}
> +
> +	if (val >= pos)
> +		len += sysfs_emit_at(buf, len, "[unknown(%d)]", val);
> +
> +	len += sysfs_emit_at(buf, len, "\n");
> +
> +	return len;
> +}
> +
> +static ssize_t aspeed_uart_routing_store(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t count)
> +{
> +	struct aspeed_uart_routing *uart_routing = dev_get_drvdata(dev);
> +	struct aspeed_uart_routing_selector *sel = to_routing_selector(attr);
> +	int val;
> +
> +	val = match_string(sel->options, -1, buf);
> +	if (val < 0) {
> +		dev_err(dev, "invalid value \"%s\"\n", buf);
> +		return -EINVAL;
> +	}
> +
> +	regmap_update_bits(uart_routing->map, sel->reg,
> +			(sel->mask << sel->shift),
> +			(val & sel->mask) << sel->shift);
> +
> +	return count;
> +}
> +
> +static int aspeed_uart_routing_probe(struct platform_device *pdev) {
> +	int rc;
> +	struct device *dev = &pdev->dev;
> +	struct aspeed_uart_routing *uart_routing;
> +
> +	uart_routing = devm_kzalloc(&pdev->dev, sizeof(*uart_routing),
> GFP_KERNEL);
> +	if (!uart_routing)
> +		return -ENOMEM;
> +
> +	uart_routing->map = syscon_node_to_regmap(dev->parent->of_node);
> +	if (IS_ERR(uart_routing->map)) {
> +		dev_err(dev, "cannot get regmap\n");
> +		return PTR_ERR(uart_routing->map);
> +	}
> +
> +	uart_routing->attr_grp = of_device_get_match_data(dev);
> +
> +	rc = sysfs_create_group(&dev->kobj, uart_routing->attr_grp);
> +	if (rc < 0)
> +		return rc;
> +
> +	dev_set_drvdata(dev, uart_routing);
> +
> +	dev_info(dev, "module loaded\n");
> +
> +	return 0;
> +}
> +
> +static int aspeed_uart_routing_remove(struct platform_device *pdev) {
> +	struct device *dev = &pdev->dev;
> +	struct aspeed_uart_routing *uart_routing = platform_get_drvdata(pdev);
> +
> +	sysfs_remove_group(&dev->kobj, uart_routing->attr_grp);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id aspeed_uart_routing_table[] = {
> +	{ .compatible = "aspeed,ast2500-uart-routing",
> +	  .data = &ast2500_uart_routing_attr_group },
> +	{ .compatible = "aspeed,ast2600-uart-routing",
> +	  .data = &ast2600_uart_routing_attr_group },
> +	{ },
> +};
> +
> +static struct platform_driver aspeed_uart_routing_driver = {
> +	.driver = {
> +		.name = "aspeed-uart-routing",
> +		.of_match_table = aspeed_uart_routing_table,
> +	},
> +	.probe = aspeed_uart_routing_probe,
> +	.remove = aspeed_uart_routing_remove,
> +};
> +
> +module_platform_driver(aspeed_uart_routing_driver);
> +
> +MODULE_AUTHOR("Oskar Senft <osk at google.com>");
> MODULE_AUTHOR("Chia-Wei
> +Wang <chiawei_wang at aspeedtech.com>"); MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Driver to configure Aspeed UART routing");
> --
> 2.17.1



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