Re: [PATCH v2 2/7] i3c: Add core I3C infrastructure

Randy Dunlap
2017-12-17T22:32:04Z

On 12/14/17 07:16, Boris Brezillon wrote:
> Add core infrastructure to support I3C in Linux and document it.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> drivers/Kconfig | 2 +
> drivers/Makefile | 2 +-
> drivers/i3c/Kconfig | 24 +
> drivers/i3c/Makefile | 4 +
> drivers/i3c/core.c | 573 ++++++++++++++++
> drivers/i3c/device.c | 344 ++++++++++
> drivers/i3c/internals.h | 34 +
> drivers/i3c/master.c | 1433 +++++++++++++++++++++++++++++++++++++++
> drivers/i3c/master/Kconfig | 0
> drivers/i3c/master/Makefile | 0
> include/linux/i3c/ccc.h | 380 +++++++++++
> include/linux/i3c/device.h | 321 +++++++++
> include/linux/i3c/master.h | 564 +++++++++++++++
> include/linux/mod_devicetable.h | 17 +
> 14 files changed, 3697 insertions(+), 1 deletion(-)
> create mode 100644 drivers/i3c/Kconfig
> create mode 100644 drivers/i3c/Makefile
> create mode 100644 drivers/i3c/core.c
> create mode 100644 drivers/i3c/device.c
> create mode 100644 drivers/i3c/internals.h
> create mode 100644 drivers/i3c/master.c
> create mode 100644 drivers/i3c/master/Kconfig
> create mode 100644 drivers/i3c/master/Makefile
> create mode 100644 include/linux/i3c/ccc.h
> create mode 100644 include/linux/i3c/device.h
> create mode 100644 include/linux/i3c/master.h
>
> diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig
> new file mode 100644
> index 000000000000..cf3752412ae9
> --- /dev/null
> +++ b/drivers/i3c/Kconfig
> @@ -0,0 +1,24 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +menuconfig I3C
> + tristate "I3C support"
> + select I2C
> + help
> + I3C is a serial protocol standardized by the MIPI alliance.
> +
> + It's supposed to be backward compatible with I2C while providing
> + support for high speed transfers and native interrupt support
> + without the need for extra pins.
> +
> + The I3C protocol also standardizes the slave device types and is
> + mainly design to communicate with sensors.
> +
> + If you want I3C support, you should say Y here and also to the
> + specific driver for your bus adapter(s) below.
> +
> + This I3C support can also be built as a module. If so, the module
> + will be called i3c.
> +
> +if I3C
> +source "drivers/i3c/master/Kconfig"
> +endif # I3C

> diff --git a/drivers/i3c/core.c b/drivers/i3c/core.c
> new file mode 100644
> index 000000000000..7eb8e84acd33
> --- /dev/null
> +++ b/drivers/i3c/core.c
> @@ -0,0 +1,573 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + *
> + * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> + */
> +
> +#include <linux/idr.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/slab.h>

#include <linux/device.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>

> +#include "internals.h"
> +
> +static DEFINE_IDR(i3c_bus_idr);
> +static DEFINE_MUTEX(i3c_core_lock);
> +

> +/**
> + * i3c_bus_maintenance_lock - Release the bus lock after a maintenance

unlock

> + * operation
> + * @bus: I3C bus to release the lock on
> + *
> + * Should be called when the bus maintenance operation is done. See
> + * i3c_bus_maintenance_lock() for more details on what these maintenance
> + * operations are.
> + */
> +void i3c_bus_maintenance_unlock(struct i3c_bus *bus)
> +{
> + up_write(&bus->lock);
> +}
> +EXPORT_SYMBOL_GPL(i3c_bus_maintenance_unlock);
> +

> +/**
> + * i3c_bus_normaluse_lock - Release the bus lock after a normal operation

unlock

> + * @bus: I3C bus to release the lock on
> + *
> + * Should be called when a normal operation is done. See
> + * i3c_bus_normaluse_lock() for more details on what these normal operations
> + * are.
> + */
> +void i3c_bus_normaluse_unlock(struct i3c_bus *bus)
> +{
> + up_read(&bus->lock);
> +}
> +EXPORT_SYMBOL_GPL(i3c_bus_normaluse_unlock);

> +static int i3c_device_match(struct device *dev, struct device_driver *drv)

bool?

> +{
> + struct i3c_device *i3cdev;
> + struct i3c_driver *i3cdrv;
> +
> + if (dev->type != &i3c_device_type)
> + return 0;
> +
> + i3cdev = dev_to_i3cdev(dev);
> + i3cdrv = drv_to_i3cdrv(drv);
> + if (i3c_device_match_id(i3cdev, i3cdrv->id_table))
> + return 1;
> +
> + return 0;
> +}

> diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c
> new file mode 100644
> index 000000000000..dcf51150b7cb
> --- /dev/null
> +++ b/drivers/i3c/device.c
> @@ -0,0 +1,344 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + *
> + * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> + */
> +
> +#include <linux/slab.h>

#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/mutex.h>

> +#include "internals.h"

> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> new file mode 100644
> index 000000000000..1c85abac08d5
> --- /dev/null
> +++ b/drivers/i3c/master.c
> @@ -0,0 +1,1433 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + *
> + * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> + */

#include <linux/atomic.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/of.h>

> +#include <linux/slab.h>

#include <linux/spinlock.h>
#include <linux/workqueue.h>

#include <asm-generic/bug.h>

> +#include "internals.h"

and I probably missed a few.

> diff --git a/include/linux/i3c/ccc.h b/include/linux/i3c/ccc.h
> new file mode 100644
> index 000000000000..ff3e1a3e2c4c
> --- /dev/null
> +++ b/include/linux/i3c/ccc.h
> @@ -0,0 +1,380 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + *
> + * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> + */

> +/**
> + * struct i3c_ccc_dev_desc - I3C/I3C device descriptor used for DEFSLVS

Is one of those I3C above supposed to be I2C?

> + *
> + * @dyn_addr: dynamic address assigned to the I3C slave or 0 if the entry is
> + * describing an I2C slave.
> + * @dcr: DCR value (not applicable to entries describing I2C devices)
> + * @lvr: LVR value (not applicable to entries describing I3C devices)
> + * @bcr: BCR value or 0 if this entry is describing an I2C slave
> + * @static_addr: static address or 0 if the device does not have a static
> + * address
> + *
> + * The DEFSLVS command should be passed an array of i3c_ccc_dev_desc
> + * descriptors (one entry per I3C/I2C dev controlled by the master).
> + */
> +struct i3c_ccc_dev_desc {
> + u8 dyn_addr;
> + union {
> + u8 dcr;
> + u8 lvr;
> + };
> + u8 bcr;
> + u8 static_addr;
> +} __packed;

Needs bitops.h

> diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
> new file mode 100644
> index 000000000000..83958d3a02e2
> --- /dev/null
> +++ b/include/linux/i3c/device.h
> @@ -0,0 +1,321 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + *
> + * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> + */
> +
> +#ifndef I3C_DEV_H
> +#define I3C_DEV_H
> +
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>

Needs bitops.h, kconfig.h.

> diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
> new file mode 100644
> index 000000000000..7ec9a4821bac
> --- /dev/null
> +++ b/include/linux/i3c/master.h
> @@ -0,0 +1,564 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + *
> + * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> + */
> +
> +#ifndef I3C_MASTER_H
> +#define I3C_MASTER_H
> +
> +#include <linux/i2c.h>
> +#include <linux/i3c/ccc.h>
> +#include <linux/i3c/device.h>
> +#include <linux/spinlock.h>
> +
> +#define I3C_HOT_JOIN_ADDR 0x2
> +#define I3C_BROADCAST_ADDR 0x7e
> +#define I3C_MAX_ADDR GENMASK(6, 0)
> +

Needs bitops.h, workqueue.h, rwsem.h

Needs <asm-generic/bitsperlong.h>

> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
> index abb6dc2ebbf8..e59da92d8ac9 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -442,6 +442,23 @@ struct pci_epf_device_id {
> kernel_ulong_t driver_data;
> };
>
> +/* i3c */
> +
> +#define I3C_MATCH_DCR BIT(0)
> +#define I3C_MATCH_MANUF BIT(1)
> +#define I3C_MATCH_PART BIT(2)
> +#define I3C_MATCH_EXTRA_INFO BIT(3)

Needs bitops.h.

> +struct i3c_device_id {
> + __u8 match_flags;
> + __u8 dcr;
> + __u16 manuf_id;
> + __u16 part_id;
> + __u16 extra_info;
> +
> + const void *data;
> +};
> +
> /* spi */
>
> #define SPI_NAME_SIZE 32
>

--
~Randy