[PATCH v2 4/4] mux: lan966: Add support for flexcom mux controller
Claudiu.Beznea at microchip.com
Claudiu.Beznea at microchip.com
Wed May 11 02:06:36 PDT 2022
Hi, Kavyasree,
On 09.05.2022 11:49, Kavyasree Kotagiri wrote:
> LAN966 SoC have 5 flexcoms. Each flexcom has 2 chip-selects.
> For each chip select of each flexcom there is a configuration
> register FLEXCOM_SHARED[0-4]:SS_MASK[0-1]. The width of
> configuration register is 21 because there are 21 shared pins
> on each of which the chip select can be mapped. Each bit of the
> register represents a different FLEXCOM_SHARED pin.
>
> Signed-off-by: Kavyasree Kotagiri <kavyasree.kotagiri at microchip.com>
> ---
> arch/arm/mach-at91/Kconfig | 2 +
> drivers/mfd/atmel-flexcom.c | 55 +++++++++++++++-
> drivers/mux/Kconfig | 12 ++++
> drivers/mux/Makefile | 2 +
> drivers/mux/lan966-flx.c | 121 ++++++++++++++++++++++++++++++++++++
> 5 files changed, 191 insertions(+), 1 deletion(-)
> create mode 100644 drivers/mux/lan966-flx.c
>
> diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
> index 279810381256..26fb0f4e1b79 100644
> --- a/arch/arm/mach-at91/Kconfig
> +++ b/arch/arm/mach-at91/Kconfig
> @@ -74,6 +74,8 @@ config SOC_LAN966
> select DW_APB_TIMER_OF
> select ARM_GIC
> select MEMORY
> + select MULTIPLEXER
> + select MUX_LAN966
> help
> This enables support for ARMv7 based Microchip LAN966 SoC family.
>
> diff --git a/drivers/mfd/atmel-flexcom.c b/drivers/mfd/atmel-flexcom.c
> index 559eb4d352b6..7cfd0fc3f4f0 100644
> --- a/drivers/mfd/atmel-flexcom.c
> +++ b/drivers/mfd/atmel-flexcom.c
> @@ -17,6 +17,7 @@
> #include <linux/io.h>
> #include <linux/clk.h>
> #include <dt-bindings/mfd/atmel-flexcom.h>
> +#include <linux/mux/consumer.h>
>
> /* I/O register offsets */
> #define FLEX_MR 0x0 /* Mode Register */
> @@ -28,6 +29,10 @@
> #define FLEX_MR_OPMODE(opmode) (((opmode) << FLEX_MR_OPMODE_OFFSET) & \
> FLEX_MR_OPMODE_MASK)
>
> +struct atmel_flex_caps {
> + bool has_flx_mux;
> +};
> +
> struct atmel_flexcom {
> void __iomem *base;
> u32 opmode;
> @@ -37,6 +42,7 @@ struct atmel_flexcom {
> static int atmel_flexcom_probe(struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node;
> + const struct atmel_flex_caps *caps;
> struct resource *res;
> struct atmel_flexcom *ddata;
> int err;
> @@ -76,13 +82,60 @@ static int atmel_flexcom_probe(struct platform_device *pdev)
> */
> writel(FLEX_MR_OPMODE(ddata->opmode), ddata->base + FLEX_MR);
>
> + caps = of_device_get_match_data(&pdev->dev);
> + if (!caps) {
> + dev_err(&pdev->dev, "Could not retrieve flexcom caps\n");
> + return -EINVAL;
> + }
> +
> + /* Flexcom Mux */
> + if (caps->has_flx_mux && of_property_read_bool(np, "mux-controls")) {
> + struct mux_control *flx_mux;
> + struct of_phandle_args args;
> + int i, count;
> +
> + flx_mux = devm_mux_control_get(&pdev->dev, NULL);
> + if (IS_ERR(flx_mux))
> + return PTR_ERR(flx_mux);
> +
> + count = of_property_count_strings(np, "mux-control-names");
> + for (i = 0; i < count; i++) {
> + err = of_parse_phandle_with_fixed_args(np, "mux-controls", 1, i, &args);
> + if (err)
> + break;
> +
> + err = mux_control_select(flx_mux, args.args[0]);
> + if (!err) {
> + mux_control_deselect(flx_mux);
> + } else {
> + dev_err(&pdev->dev, "Failed to select FLEXCOM mux\n");
> + return err;
> + }
> + }
> + }
> +
Can you move this in a separate function and take care of disabling the
clock on error cases?
> clk_disable_unprepare(ddata->clk);
>
> return devm_of_platform_populate(&pdev->dev);
> }
>
> +static const struct atmel_flex_caps atmel_flexcom_caps = {};
> +
> +static const struct atmel_flex_caps lan966x_flexcom_caps = {
> + .has_flx_mux = true,
> +};
> +
> static const struct of_device_id atmel_flexcom_of_match[] = {
> - { .compatible = "atmel,sama5d2-flexcom" },
> + {
> + .compatible = "atmel,sama5d2-flexcom",
> + .data = &atmel_flexcom_caps,
> + },
> +
> + {
> + .compatible = "microchip,lan966-flexcom",
> + .data = &lan966x_flexcom_caps,
> + },
> +
> { /* sentinel */ }
> };
> MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match);
> diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
> index e5c571fd232c..ea09f474bc2f 100644
> --- a/drivers/mux/Kconfig
> +++ b/drivers/mux/Kconfig
> @@ -45,6 +45,18 @@ config MUX_GPIO
> To compile the driver as a module, choose M here: the module will
> be called mux-gpio.
>
> +config MUX_LAN966
> + tristate "LAN966 Flexcom multiplexer"
> + depends on OF || COMPILE_TEST
> + help
> + Lan966 Flexcom Multiplexer controller.
> +
> + The driver supports mapping 2 chip-selects of each of the lan966
> + flexcoms to 21 flexcom shared pins.
> +
> + To compile the driver as a module, choose M here: the module will
> + be called mux-lan966.
Ussually the help message is aligned 2 spaces on right after help.
> +
> config MUX_MMIO
> tristate "MMIO/Regmap register bitfield-controlled Multiplexer"
> depends on OF || COMPILE_TEST
> diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
> index 6e9fa47daf56..53a9840d96fa 100644
> --- a/drivers/mux/Makefile
> +++ b/drivers/mux/Makefile
> @@ -7,10 +7,12 @@ mux-core-objs := core.o
> mux-adg792a-objs := adg792a.o
> mux-adgs1408-objs := adgs1408.o
> mux-gpio-objs := gpio.o
> +mux-lan966-objs := lan966-flx.o
> mux-mmio-objs := mmio.o
>
> obj-$(CONFIG_MULTIPLEXER) += mux-core.o
> obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o
> obj-$(CONFIG_MUX_ADGS1408) += mux-adgs1408.o
> obj-$(CONFIG_MUX_GPIO) += mux-gpio.o
> +obj-$(CONFIG_MUX_LAN966) += mux-lan966.o
> obj-$(CONFIG_MUX_MMIO) += mux-mmio.o
> diff --git a/drivers/mux/lan966-flx.c b/drivers/mux/lan966-flx.c
> new file mode 100644
> index 000000000000..2c7dab616a6a
> --- /dev/null
> +++ b/drivers/mux/lan966-flx.c
> @@ -0,0 +1,121 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * LAN966 Flexcom MUX driver
> + *
> + * Copyright (c) 2022 Microchip Inc.
> + *
> + * Author: Kavyasree Kotagiri <kavyasree.kotagiri at microchip.com>
> + */
> +
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/mux/driver.h>
> +#include <linux/io.h>
> +
> +#define FLEX_SHRD_MASK 0x1FFFFF
Or you can use GENMASK()
> +#define LAN966_MAX_CS 21
> +
> +static void __iomem *flx_shared_base;
I agree with Peter's point of view on this.
> +struct mux_lan966x {
> + u32 offset;
> + u32 ss_pin;
> +};
> +
> +static int mux_lan966x_set(struct mux_control *mux, int state)
> +{
> + struct mux_lan966x *mux_lan966x = mux_chip_priv(mux->chip);
> + u32 val;
> +
> + val = ~(1 << mux_lan966x[state].ss_pin) & FLEX_SHRD_MASK;
> + writel(val, flx_shared_base + mux_lan966x[state].offset);
writel_relaxed should be enough here.
> +
> + return 0;
> +}
> +
> +static const struct mux_control_ops mux_lan966x_ops = {
> + .set = mux_lan966x_set,
> +};
> +
> +static const struct of_device_id mux_lan966x_dt_ids[] = {
> + { .compatible = "microchip,lan966-flx-mux", },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mux_lan966x_dt_ids);
> +
> +static int mux_lan966x_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct device *dev = &pdev->dev;
> + struct mux_lan966x *mux_lan966x;
> + struct mux_chip *mux_chip;
> + int ret, num_fields, i;
> +
> + ret = of_property_count_u32_elems(np, "mux-offset-pin");
> + if (ret == 0 || ret % 2)
> + ret = -EINVAL;
> + if (ret < 0)
> + return dev_err_probe(dev, ret,
> + "mux-offset-pin property missing or invalid");
> + num_fields = ret / 2;
> +
> + mux_chip = devm_mux_chip_alloc(dev, num_fields, sizeof(*mux_lan966x));
> + if (IS_ERR(mux_chip))
> + return dev_err_probe(dev, PTR_ERR(mux_chip),
> + "failed to allocate mux_chips\n");
> +
> + mux_lan966x = mux_chip_priv(mux_chip);
> +
> + flx_shared_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
> + if (IS_ERR(flx_shared_base))
> + return dev_err_probe(dev, PTR_ERR(flx_shared_base),
> + "failed to get flexcom shared base address\n");
> +
> + for (i = 0; i < num_fields; i++) {
> + struct mux_control *mux = &mux_chip->mux[i];
> + u32 offset, shared_pin;
> +
> + ret = of_property_read_u32_index(np, "mux-offset-pin",
> + 2 * i, &offset);
> + if (ret == 0)
> + ret = of_property_read_u32_index(np, "mux-offset-pin",
> + 2 * i + 1,
> + &shared_pin);
> + if (ret < 0)
> + return dev_err_probe(dev, ret,
> + "failed to read mux-offset-pin property: %d", i);
> +
> + if (shared_pin >= LAN966_MAX_CS)
> + return -EINVAL;
> +
> + mux_lan966x[i].offset = offset;
> + mux_lan966x[i].ss_pin = shared_pin;
> +
> + mux->states = LAN966_MAX_CS;
> + }
> +
> + mux_chip->ops = &mux_lan966x_ops;
> +
> + ret = devm_mux_chip_register(dev, mux_chip);
> + if (ret < 0)
> + return ret;
> +
> + return 0;
you can just return ret; or return devm_mux_chip_register(dev, mux_chip);
> +}
> +
> +static struct platform_driver mux_lan966x_driver = {
> + .driver = {
> + .name = "lan966-mux",
> + .of_match_table = of_match_ptr(mux_lan966x_dt_ids),
> + },
> + .probe = mux_lan966x_probe,
> +};
> +
> +module_platform_driver(mux_lan966x_driver);
> +
> +MODULE_DESCRIPTION("LAN966 Flexcom multiplexer driver");
> +MODULE_AUTHOR("Kavyasree Kotagiri <kavyasree.kotagiri at microchip.com>");
> +MODULE_LICENSE("GPL v2");
Last time I checked checkpatch.pl complained about using "GPL v2" string
here and suggested to use "GPL".
> +
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