Re: [PATCH 1/3] remap: Add I3C bus support

Boris Brezillon
2019-04-16T06:15:59Z

Typo in the subject: s/remap/regmap/

On Mon, 15 Apr 2019 21:19:39 +0200
Vitor Soares <vitor.soares@synopsys.com> wrote:

> Add basic support for I3C bus.
> This is a simple implementation that only give support
> for Read and Write commands.
>
> Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
> ---
> drivers/base/regmap/Kconfig | 6 +++-
> drivers/base/regmap/Makefile | 1 +
> drivers/base/regmap/regmap-i3c.c | 62 ++++++++++++++++++++++++++++++++++++++++
> include/linux/regmap.h | 20 +++++++++++++
> 4 files changed, 88 insertions(+), 1 deletion(-)
> create mode 100644 drivers/base/regmap/regmap-i3c.c
>
> diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
> index 6ad5ef4..c8bbf53 100644
> --- a/drivers/base/regmap/Kconfig
> +++ b/drivers/base/regmap/Kconfig
> @@ -4,7 +4,7 @@
> # subsystems should select the appropriate symbols.
>
> config REGMAP
> - default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ)
> + default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ || REGMAP_I3C)
> select IRQ_DOMAIN if REGMAP_IRQ
> bool
>
> @@ -49,3 +49,7 @@ config REGMAP_SOUNDWIRE
> config REGMAP_SCCB
> tristate
> depends on I2C
> +
> +config REGMAP_I3C
> + tristate
> + depends on I3C
> diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
> index f5b4e88..ff6c7d8 100644
> --- a/drivers/base/regmap/Makefile
> +++ b/drivers/base/regmap/Makefile
> @@ -16,3 +16,4 @@ obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o
> obj-$(CONFIG_REGMAP_W1) += regmap-w1.o
> obj-$(CONFIG_REGMAP_SOUNDWIRE) += regmap-sdw.o
> obj-$(CONFIG_REGMAP_SCCB) += regmap-sccb.o
> +obj-$(CONFIG_REGMAP_I3C) += regmap-i3c.o
> diff --git a/drivers/base/regmap/regmap-i3c.c b/drivers/base/regmap/regmap-i3c.c
> new file mode 100644
> index 0000000..565997b
> --- /dev/null
> +++ b/drivers/base/regmap/regmap-i3c.c
> @@ -0,0 +1,62 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018 Synopsys, Inc. and/or its affiliates.
> + *
> + * Author: Vitor Soares <vitor.soares@synopsys.com>
> + */
> +
> +#include <linux/regmap.h>
> +#include <linux/i3c/device.h>
> +#include <linux/i3c/master.h>
> +#include <linux/module.h>
> +
> +static int regmap_i3c_write(void *context, const void *data, size_t count)
> +{
> + struct device *dev = context;
> + struct i3c_device *i3c = dev_to_i3cdev(dev);
> + struct i3c_priv_xfer xfers[] = {
> + {
> + .rnw = false,
> + .len = count,
> + .data.out = data,
> + },
> + };
> +
> + return i3c_device_do_priv_xfers(i3c, xfers, 1);
> +}
> +
> +static int regmap_i3c_read(void *context,
> + const void *reg, size_t reg_size,
> + void *val, size_t val_size)
> +{
> + struct device *dev = context;
> + struct i3c_device *i3c = dev_to_i3cdev(dev);
> + struct i3c_priv_xfer xfers[2];
> +
> + xfers[0].rnw = false;
> + xfers[0].len = reg_size;
> + xfers[0].data.out = reg;
> +
> + xfers[1].rnw = true;
> + xfers[1].len = val_size;
> + xfers[1].data.in = val;
> +
> + return i3c_device_do_priv_xfers(i3c, xfers, 2);
> +}
> +
> +static struct regmap_bus regmap_i3c = {
> + .write = regmap_i3c_write,
> + .read = regmap_i3c_read,
> +};
> +
> +struct regmap *__devm_regmap_init_i3c(struct i3c_device *i3c,
> + const struct regmap_config *config,
> + struct lock_class_key *lock_key,
> + const char *lock_name)
> +{
> + return __devm_regmap_init(&i3c->dev, &regmap_i3c, &i3c->dev, config,
> + lock_key, lock_name);
> +}
> +EXPORT_SYMBOL_GPL(__devm_regmap_init_i3c);
> +
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/regmap.h b/include/linux/regmap.h
> index daeec7d..f65984d 100644
> --- a/include/linux/regmap.h
> +++ b/include/linux/regmap.h
> @@ -25,6 +25,7 @@ struct module;
> struct clk;
> struct device;
> struct i2c_client;
> +struct i3c_device;
> struct irq_domain;
> struct slim_device;
> struct spi_device;
> @@ -624,6 +625,10 @@ struct regmap *__devm_regmap_init_slimbus(struct slim_device *slimbus,
> const struct regmap_config *config,
> struct lock_class_key *lock_key,
> const char *lock_name);
> +struct regmap *__devm_regmap_init_i3c(struct i3c_device *i3c,
> + const struct regmap_config *config,
> + struct lock_class_key *lock_key,
> + const char *lock_name);
> /*
> * Wrapper for regmap_init macros to include a unique lockdep key and name
> * for each call. No-op if CONFIG_LOCKDEP is not set.
> @@ -982,6 +987,21 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);
> #define devm_regmap_init_slimbus(slimbus, config) \
> __regmap_lockdep_wrapper(__devm_regmap_init_slimbus, #config, \
> slimbus, config)
> +
> +/**
> + * devm_regmap_init_i3c() - Initialise managed register map

Maybe we should have a more specific name here, as some might want to
access registers using HDR modes (devm_regmap_init_i3c_sdr()?)

> + *
> + * @i3c: Device that will be interacted with
> + * @config: Configuration for register map
> + *
> + * The return value will be an ERR_PTR() on error or a valid pointer
> + * to a struct regmap. The regmap will be automatically freed by the
> + * device management code.
> + */
> +#define devm_regmap_init_i3c(i3c, config) \
> + __regmap_lockdep_wrapper(__devm_regmap_init_i3c, #config, \
> + i3c, config)
> +
> int regmap_mmio_attach_clk(struct regmap *map, struct clk *clk);
> void regmap_mmio_detach_clk(struct regmap *map);
> void regmap_exit(struct regmap *map);