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

Vitor Soares
2019-04-16T14:41:59Z

Hi Boris,

From: Boris Brezillon <boris.brezillon@collabora.com>
Date: Tue, Apr 16, 2019 at 07:15:51

> 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()?)

That make sense if the device with HDR capability is able to do
everything in HDR mode and I'm not sure about that.
I would like to wait for a couple of commercial devices before that
change.

>
>
> > + *
> > + * @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);

Thanks for your feedback.

Best regards,
Vitor Soares