Hi Philipp,
With the ack on the bindings in place, I'm going to pile these
two patches on top of my mux series when I send v15 next week (or
whenever v4.12-rc1 is out). There are a pair of nitpicks that I'm
going to fix myself, so no need for a resend.
Thank you very much for making use of the new code, I hope the
"3rd party interest" will help getting the mux series merged...
On 2017-04-28 13:52, Philipp Zabel wrote:
> This adds a driver for mmio-based syscon multiplexers controlled by
> bitfields in a syscon register range.
>
> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> ---
> Changes since v2:
> - Updated CONFIG description to multi-mux
> - Use mux_control_get_index instead of open-coding it
> - Read mux-reg-masks and idle-states values in a single loop using
> individual read_u32_index calls instead of using read_u32_array
> - Verify bitmask
> ---
> drivers/mux/Kconfig | 13 +++++
> drivers/mux/Makefile | 1 +
> drivers/mux/mux-mmio.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 154 insertions(+)
> create mode 100644 drivers/mux/mux-mmio.c
>
> diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
> index 34b8284d6d29e..50e7c5d557a05 100644
> --- a/drivers/mux/Kconfig
> +++ b/drivers/mux/Kconfig
> @@ -43,4 +43,17 @@ config MUX_GPIO
> To compile the driver as a module, choose M here: the module will
> be called mux-gpio.
>
> +config MUX_MMIO
> + tristate "MMIO register bitfield-controlled Multiplexer"
> + depends on OF && MFD_SYSCON
Enable building when COMPILE_TEST is selected:
depends on (OF && MFD_SYSCON) || COMPILE_TEST
(also adding that to the other drivers in the mux series)
> + help
> + MMIO register bitfield-controlled Multiplexer controller.
> +
> + The driver builds multiplexer controllers for bitfields in a syscon
> + 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 mux-mmio.
> +
> endif
> diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
> index b00a7d37d2fbe..6bac5b0fea137 100644
> --- a/drivers/mux/Makefile
> +++ b/drivers/mux/Makefile
> @@ -5,3 +5,4 @@
> obj-$(CONFIG_MULTIPLEXER) += mux-core.o
> obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o
> obj-$(CONFIG_MUX_GPIO) += mux-gpio.o
> +obj-$(CONFIG_MUX_MMIO) += mux-mmio.o
> diff --git a/drivers/mux/mux-mmio.c b/drivers/mux/mux-mmio.c
> new file mode 100644
> index 0000000000000..d2477d62d6eed
> --- /dev/null
> +++ b/drivers/mux/mux-mmio.c
> @@ -0,0 +1,140 @@
> +/*
> + * MMIO register bitfield-controlled multiplexer driver
> + *
> + * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@xxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/err.h>
> +#include <linux/mfd/syscon.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_mmio_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_mmio_ops = {
> + .set = mux_mmio_set,
> +};
> +
> +static const struct of_device_id mux_mmio_dt_ids[] = {
> + { .compatible = "mmio-mux", },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mux_mmio_dt_ids);
> +
> +static int mux_mmio_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 = syscon_node_to_regmap(np->parent);
> + 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, ®);
> + 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, &idle_state);
Adding a (u32 *) cast here, in order to silence sparse.
drivers/mux/mux-mmio.c:112:67: warning: incorrect type in argument 4 (different signedness)
drivers/mux/mux-mmio.c:112:67: expected unsigned int [usertype] *out_value
drivers/mux/mux-mmio.c:112:67: got signed int *<noident>
Cheers,
peda
> + 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_mmio_ops;
> +
> + return devm_mux_chip_register(dev, mux_chip);
> +}
> +
> +static struct platform_driver mux_mmio_driver = {
> + .driver = {
> + .name = "mmio-mux",
> + .of_match_table = of_match_ptr(mux_mmio_dt_ids),
> + },
> + .probe = mux_mmio_probe,
> +};
> +module_platform_driver(mux_mmio_driver);
> +
> +MODULE_DESCRIPTION("MMIO register bitfield-controlled multiplexer driver");
> +MODULE_AUTHOR("Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
>
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