[U-Boot] [RFC PATCH 06/11] drivers: Add SPMI bus uclass

[Simon Glass]

Hi Matheusz,

On 10 December 2015 at 14:41, Mateusz Kulikowski
<mateusz.kulikowski at gmail.com> wrote:
> Qualcom processors use proprietary bus to talk with PMIC devices -
> SPMI (System Power Management Interface).
> On wiring level it is similar to I2C, but on protocol level, it's
> multi-master and has simple autodetection capabilities.
> This commit adds simple uclass that provides bus read/write interface.
>
> Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski at gmail.com>
> ---
>
>  drivers/Kconfig            |  2 ++
>  drivers/Makefile           |  1 +
>  drivers/spmi/Kconfig       | 10 +++++++++
>  drivers/spmi/Makefile      |  7 ++++++
>  drivers/spmi/spmi-uclass.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/dm/uclass-id.h     |  1 +
>  include/spmi/spmi.h        | 44 ++++++++++++++++++++++++++++++++++++++
>  7 files changed, 118 insertions(+)
>  create mode 100644 drivers/spmi/Kconfig
>  create mode 100644 drivers/spmi/Makefile
>  create mode 100644 drivers/spmi/spmi-uclass.c
>  create mode 100644 include/spmi/spmi.h
>
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index c481e93..4cbe976 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -52,6 +52,8 @@ source "drivers/remoteproc/Kconfig"
>
>  source "drivers/rtc/Kconfig"
>
> +source "drivers/spmi/Kconfig"
> +
>  source "drivers/serial/Kconfig"
>
>  source "drivers/sound/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index c9031f2..7ae72c0 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -53,6 +53,7 @@ obj-y += pcmcia/
>  obj-y += dfu/
>  obj-y += rtc/
>  obj-y += sound/
> +obj-y += spmi/
>  obj-y += timer/
>  obj-y += tpm/
>  obj-y += twserial/
> diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
> new file mode 100644
> index 0000000..2d8d78b
> --- /dev/null
> +++ b/drivers/spmi/Kconfig
> @@ -0,0 +1,10 @@
> +menu "SPMI support"
> +
> +config DM_SPMI
> +       bool "Enable SPMI bus support"
> +       depends on DM
> +       ---help---
> +       Select this to enable to support SPMI bus.
> +       SPMI (System Power Management Interface) bus is used
> +       to connect PMIC devices on various SoCs.
> +endmenu
> diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
> new file mode 100644
> index 0000000..2015b1a
> --- /dev/null
> +++ b/drivers/spmi/Makefile
> @@ -0,0 +1,7 @@
> +#
> +# (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski at gmail.com>
> +#
> +# SPDX-License-Identifier:     GPL-2.0+
> +#
> +
> +obj-$(CONFIG_DM_SPMI)  += spmi-uclass.o
> diff --git a/drivers/spmi/spmi-uclass.c b/drivers/spmi/spmi-uclass.c
> new file mode 100644
> index 0000000..981da68
> --- /dev/null
> +++ b/drivers/spmi/spmi-uclass.c
> @@ -0,0 +1,53 @@
> +/*
> + * SPMI bus uclass driver
> + *
> + * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski at gmail.com>
> + *
> + * SPDX-License-Identifier:    GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <fdtdec.h>
> +#include <errno.h>
> +#include <dm.h>
> +#include <dm/root.h>
> +#include <vsprintf.h>
> +#include <dm/lists.h>
> +#include <dm/device-internal.h>
> +#include <dm/uclass-internal.h>
> +#include <linux/ctype.h>
> +#include <spmi/spmi.h>

Fix ordering

> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +int spmi_reg_read(struct udevice *dev, int usid, int pid, int reg)
> +{
> +       const struct dm_spmi_ops *ops = dev_get_driver_ops(dev);
> +
> +       if (!ops || !ops->read)
> +               return -ENOSYS;
> +
> +       return ops->read(dev, usid, pid, reg);
> +}
> +
> +int spmi_reg_write(struct udevice *dev, int usid, int pid, int reg,
> +                  uint8_t value)
> +{
> +       const struct dm_spmi_ops *ops = dev_get_driver_ops(dev);
> +
> +       if (!ops || !ops->write)
> +               return -ENOSYS;
> +
> +       return ops->write(dev, usid, pid, reg, value);
> +}
> +
> +static int msm_spmi_post_bind(struct udevice *dev)
> +{
> +       return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
> +}
> +
> +UCLASS_DRIVER(spmi) = {
> +       .id             = UCLASS_SPMI,
> +       .name           = "spmi",
> +       .post_bind      = msm_spmi_post_bind,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 27fa0b6..772e780 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -57,6 +57,7 @@ enum uclass_id {
>         UCLASS_RTC,             /* Real time clock device */
>         UCLASS_SERIAL,          /* Serial UART */
>         UCLASS_SPI,             /* SPI bus */
> +       UCLASS_SPMI,            /* System Power Management Interface bus */
>         UCLASS_SPI_FLASH,       /* SPI flash */
>         UCLASS_SPI_GENERIC,     /* Generic SPI flash target */
>         UCLASS_SYSCON,          /* System configuration device */
> diff --git a/include/spmi/spmi.h b/include/spmi/spmi.h
> new file mode 100644
> index 0000000..e06a79e
> --- /dev/null
> +++ b/include/spmi/spmi.h
> @@ -0,0 +1,44 @@
> +#ifndef _SPMI_SPMI_H
> +#define _SPMI_SPMI_H
> +
> +/**
> + * struct dm_spmi_ops - SPMI device I/O interface
> + *
> + * Should be implemented by UCLASS_SPMI device drivers. The standard
> + * device operations provides the I/O interface for it's childs.
> + *
> + * @read:      read register
> + * @write:     write register

You should describe the args also.

What is different between this and I2C? Could you use that uclass? It
seems to have an additional address value (pid)- is that right?

If you do end up with a new uclass, please add a sandbox driver for it
and a test.

> + */
> +struct dm_spmi_ops {
> +       int (*read)(struct udevice *dev, int usid, int pid, int reg);
> +       int (*write)(struct udevice *dev, int usid, int pid, int reg,
> +                    uint8_t value);
> +};
> +
> +/**
> + * spmi_reg_read() - read a register from specific slave/peripheral
> + *
> + * @dev:       SPMI bus to read
> + * @usid       SlaveID
> + * @pid                Peripheral ID
> + * @reg:       Register to read
> + * @return value read on success or negative value of errno.
> + */
> +int spmi_reg_read(struct udevice *dev, int usid, int pid, int reg);
> +
> +/**
> + * spmi_reg_write() - write a register of specific slave/peripheral
> + *
> + * @dev:       SPMI bus to write
> + * @usid       SlaveID
> + * @pid                Peripheral ID
> + * @reg:       Register to write
> + * @value:     Value to write
> + * @return 0 on success or negative value of errno.
> + */
> +int spmi_reg_write(struct udevice *dev, int usid, int pid, int reg,
> +                  uint8_t value);
> +
> +#endif
> +
> --
> 2.5.0
>

Regards,
Simon