Hi!

On 2019-02-18 06:40, Pankaj Bansal wrote:
> Generic register bitfield-based multiplexer driver that controls the
> multiplexer producer defined under a parent node.
> The driver corresponding to parent node provides register read/write
> capabilities.

This driver is just a rename of drivers/mux/mmio.c with a one-liner on
top. And there's a license change too. That's obnoxious. Please keep
this as GPL v2. Not that I /think/ Philipp nor Pengutronix cares deeply,
but what do I know? Changing the license as you copy the code is simply
not all right.

Anyway, I would prefer if you could extend drivers/mux/mmio.c to support
both compatibles, and using the compatible to select if

        regmap = syscon_node_to_regmap(np->parent);

or

        regmap = dev_get_regmap(dev->parent, NULL);
        
is called to get to the desired regmap.

Philipp, you don't object to extending the mmio driver, right?

Or are there more differences that I failed to notice?

Cheers,
Peter

> 
> Signed-off-by: Pankaj Bansal <pankaj.ban...@nxp.com>
> ---
> 
> Notes:
>     Dependencies:
>     - https://patchwork.ozlabs.org/patch/1043790/
> 
>  drivers/mux/Kconfig  |  13 ++++
>  drivers/mux/Makefile |   2 +
>  drivers/mux/regmap.c | 139 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 154 insertions(+)
> 
> diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
> index 7659d6c5f718..a412d0955258 100644
> --- a/drivers/mux/Kconfig
> +++ b/drivers/mux/Kconfig
> @@ -58,4 +58,17 @@ config MUX_MMIO
>         To compile the driver as a module, choose M here: the module will
>         be called mux-mmio.
>  
> +config MUX_REGMAP
> +     tristate "Regmap register bitfield-controlled Multiplexer"
> +     depends on (OF && REGMAP) || COMPILE_TEST
> +     help
> +       Regmap register bitfield-controlled Multiplexer controller.
> +
> +       The driver builds multiplexer controllers for bitfields in a regmap
> +       device register. For N bit wide bitfields, there will be 2^N possible
> +       multiplexer states.
> +
> +       To compile the driver as a module, choose M here: the module will
> +       be called regmap-mmio.
> +
>  endmenu
> diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
> index 6e9fa47daf56..ae1bafac0cbd 100644
> --- a/drivers/mux/Makefile
> +++ b/drivers/mux/Makefile
> @@ -8,9 +8,11 @@ mux-adg792a-objs             := adg792a.o
>  mux-adgs1408-objs            := adgs1408.o
>  mux-gpio-objs                        := gpio.o
>  mux-mmio-objs                        := mmio.o
> +mux-regmap-objs                      := regmap.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-$(CONFIG_MUX_MMIO)               += mux-mmio.o
> +obj-$(CONFIG_MUX_REGMAP)     += mux-regmap.o
> diff --git a/drivers/mux/regmap.c b/drivers/mux/regmap.c
> new file mode 100644
> index 000000000000..c2156302929a
> --- /dev/null
> +++ b/drivers/mux/regmap.c
> @@ -0,0 +1,139 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Regmap register bitfield-controlled multiplexer driver
> + *
> + * Based on drivers/mux/mmio.c
> + *
> + * Copyright 2019 NXP
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/mux/driver.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +
> +static int mux_regmap_set(struct mux_control *mux, int state)
> +{
> +     struct regmap_field **fields = mux_chip_priv(mux->chip);
> +
> +     return regmap_field_write(fields[mux_control_get_index(mux)], state);
> +}
> +
> +static const struct mux_control_ops mux_regmap_ops = {
> +     .set = mux_regmap_set,
> +};
> +
> +static const struct of_device_id mux_regmap_dt_ids[] = {
> +     { .compatible = "reg-mux", },
> +     { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mux_regmap_dt_ids);
> +
> +static int mux_regmap_probe(struct platform_device *pdev)
> +{
> +     struct device *dev = &pdev->dev;
> +     struct device_node *np = dev->of_node;
> +     struct regmap_field **fields;
> +     struct mux_chip *mux_chip;
> +     struct regmap *regmap;
> +     int num_fields;
> +     int ret;
> +     int i;
> +
> +     regmap = dev_get_regmap(dev->parent, NULL);
> +     if (IS_ERR(regmap)) {
> +             ret = PTR_ERR(regmap);
> +             dev_err(dev, "failed to get regmap: %d\n", ret);
> +             return ret;
> +     }
> +
> +     ret = of_property_count_u32_elems(np, "mux-reg-masks");
> +     if (ret == 0 || ret % 2)
> +             ret = -EINVAL;
> +     if (ret < 0) {
> +             dev_err(dev, "mux-reg-masks property missing or invalid: %d\n",
> +                     ret);
> +             return ret;
> +     }
> +     num_fields = ret / 2;
> +
> +     mux_chip = devm_mux_chip_alloc(dev, num_fields, num_fields *
> +                                    sizeof(*fields));
> +     if (IS_ERR(mux_chip))
> +             return PTR_ERR(mux_chip);
> +
> +     fields = mux_chip_priv(mux_chip);
> +
> +     for (i = 0; i < num_fields; i++) {
> +             struct mux_control *mux = &mux_chip->mux[i];
> +             struct reg_field field;
> +             s32 idle_state = MUX_IDLE_AS_IS;
> +             u32 reg, mask;
> +             int bits;
> +
> +             ret = of_property_read_u32_index(np, "mux-reg-masks",
> +                                              2 * i, &reg);
> +             if (!ret)
> +                     ret = of_property_read_u32_index(np, "mux-reg-masks",
> +                                                      2 * i + 1, &mask);
> +             if (ret < 0) {
> +                     dev_err(dev, "bitfield %d: failed to read mux-reg-masks 
> property: %d\n",
> +                             i, ret);
> +                     return ret;
> +             }
> +
> +             field.reg = reg;
> +             field.msb = fls(mask) - 1;
> +             field.lsb = ffs(mask) - 1;
> +
> +             if (mask != GENMASK(field.msb, field.lsb)) {
> +                     dev_err(dev, "bitfield %d: invalid mask 0x%x\n",
> +                             i, mask);
> +                     return -EINVAL;
> +             }
> +
> +             fields[i] = devm_regmap_field_alloc(dev, regmap, field);
> +             if (IS_ERR(fields[i])) {
> +                     ret = PTR_ERR(fields[i]);
> +                     dev_err(dev, "bitfield %d: failed allocate: %d\n",
> +                             i, ret);
> +                     return ret;
> +             }
> +
> +             bits = 1 + field.msb - field.lsb;
> +             mux->states = 1 << bits;
> +
> +             of_property_read_u32_index(np, "idle-states", i,
> +                                        (u32 *)&idle_state);
> +             if (idle_state != MUX_IDLE_AS_IS) {
> +                     if (idle_state < 0 || idle_state >= mux->states) {
> +                             dev_err(dev, "bitfield: %d: out of range idle 
> state %d\n",
> +                                     i, idle_state);
> +                             return -EINVAL;
> +                     }
> +
> +                     mux->idle_state = idle_state;
> +             }
> +     }
> +
> +     mux_chip->ops = &mux_regmap_ops;
> +
> +     return devm_mux_chip_register(dev, mux_chip);
> +}
> +
> +static struct platform_driver mux_regmap_driver = {
> +     .driver = {
> +             .name = "regmap-mux",
> +             .of_match_table = of_match_ptr(mux_regmap_dt_ids),
> +     },
> +     .probe = mux_regmap_probe,
> +};
> +module_platform_driver(mux_regmap_driver);
> +
> +MODULE_DESCRIPTION("Regmap register bitfield-controlled multiplexer driver");
> +MODULE_AUTHOR("Pankaj Bansal <pankaj.ban...@nxp.com>");
> +MODULE_LICENSE("GPL");
> 

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