[PATCH linux v1 4/8] drivers: fsi: Add i2c client driver
Alistair Popple
alistair at popple.id.au
Fri Feb 3 11:56:33 AEDT 2017
Hi Edward,
On Thu, 2 Feb 2017 05:25:57 PM eajames at linux.vnet.ibm.com wrote:
> From: "Edward A. James" <eajames at us.ibm.com>
>
> stub for I2C driver over FSI
Unless I've missed something it doesn't look like this uses any of the
existing I2C infrastructure in the kernel. This should live in
drivers/i2c/busses and register the I2C bus adapter using
i2c_add_adapter(). This way all the existing kernel infrastructe for
probing and assiging I2C device drivers can be utilised.
For an example see how OPAL currently exposes I2C busses on the host
in drivers/i2c/busses/i2c-opal.c.
Regards,
Alistair
> Signed-off-by: Edward A. James <eajames at us.ibm.com>
> ---
> drivers/fsi/Kconfig | 6 ++
> drivers/fsi/Makefile | 1 +
> drivers/fsi/i2c/Makefile | 1 +
> drivers/fsi/i2c/iic-fsi.c | 166 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/fsi/i2c/iic-fsi.h | 29 ++++++++
> drivers/fsi/i2c/iic-int.h | 80 ++++++++++++++++++++++
> 6 files changed, 283 insertions(+)
> create mode 100644 drivers/fsi/i2c/Makefile
> create mode 100644 drivers/fsi/i2c/iic-fsi.c
> create mode 100644 drivers/fsi/i2c/iic-fsi.h
> create mode 100644 drivers/fsi/i2c/iic-int.h
>
> diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
> index 0fa265c..c78b9b6e 100644
> --- a/drivers/fsi/Kconfig
> +++ b/drivers/fsi/Kconfig
> @@ -24,6 +24,12 @@ config FSI_SCOM
> ---help---
> This option enables an FSI based SCOM device driver.
>
> +config FSI_I2C
> + tristate "I2C FSI client device driver"
> + depends on FSI
> + ---help---
> + This option enables an FSI based I2C device driver.
> +
> endif
>
> endmenu
> diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
> index 3466f08..3a106ba 100644
> --- a/drivers/fsi/Makefile
> +++ b/drivers/fsi/Makefile
> @@ -2,3 +2,4 @@
> obj-$(CONFIG_FSI) += fsi-core.o
> obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
> obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
> +obj-$(CONFIG_FSI_I2C) += i2c/
> diff --git a/drivers/fsi/i2c/Makefile b/drivers/fsi/i2c/Makefile
> new file mode 100644
> index 0000000..f9f9048
> --- /dev/null
> +++ b/drivers/fsi/i2c/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_FSI_I2C) += iic-fsi.o
> diff --git a/drivers/fsi/i2c/iic-fsi.c b/drivers/fsi/i2c/iic-fsi.c
> new file mode 100644
> index 0000000..51a15a4
> --- /dev/null
> +++ b/drivers/fsi/i2c/iic-fsi.c
> @@ -0,0 +1,166 @@
> +/*
> + * Copyright (c) International Business Machines Corp., 2006, 2010, 2012
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
> + * the GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + */
> +
> +/*
> + * This file contains the architecture independent IIC FSI code.
> + */
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/fsi.h>
> +#include <asm/io.h>
> +#include <linux/mm.h>
> +#include <linux/interrupt.h>
> +#include "iic-int.h"
> +#include "iic-fsi.h"
> +
> +#include <linux/delay.h>
> +#include <linux/moduleparam.h>
> +
> +struct class* iic_fsi_class = 0;
> +dev_t iic_devnum_start = 0;
> +
> +static const char iic_fsi_version[] = "3.0";
> +
> +int iic_fsi_probe(struct device *dev);
> +int iic_fsi_remove(struct device *dev);
> +
> +struct iic_reg_access fsi_reg_access =
> +{
> + .bus_readb = readb_wrap,
> + .bus_readh = readh_wrap,
> + .bus_readw = readw_wrap,
> + .bus_writeb = writeb_wrap,
> + .bus_writeh = writeh_wrap,
> + .bus_writew = writew_wrap,
> +};
> +
> +static const struct fsi_device_id i2c_ids[] = {
> + {
> + .engine_type = FSI_ENGID_I2C,
> + .version = FSI_VERSION_ANY,
> + },
> + {
> + .engine_type = FSI_ENGID_I2C_BB,
> + .version = FSI_VERSION_ANY,
> + },
> + { 0 }
> +};
> +
> +static const struct fsi_driver i2c_drv = {
> + .id_table = i2c_ids,
> + .drv = {
> + .name = "iic_fsi_dd",
> + .bus = &fsi_bus_type,
> + .probe = iic_fsi_probe,
> + .remove = iic_fsi_remove,
> + }
> +};
> +
> +/*
> + * Called when an FSI IIC engine is plugged in.
> + * Causes creation of the /dev entry.
> + * Not allowed to access engine registers in this function.
> + *
> + */
> +int iic_fsi_probe(struct device *dev)
> +{
> + return 0;
> +}
> +
> +/* This function is called when a link is removed or the driver is unloaded.
> + * It's job is to remove the device from the device hierarchy including
> + * removal from sysfs (this is where device files get removed).
> + */
> +int iic_fsi_remove(struct device* dev)
> +{
> + return 0;
> +}
> +
> +/*
> + * Initialize this module. Creates a class for fsi connected iic devices and
> + * allocates device numbers for them.
> + */
> +static int __init iic_fsi_init(void)
> +{
> + int rc = 0;
> +
> + IENTER();
> +
> + rc = alloc_chrdev_region(&iic_devnum_start,
> + 0, /*starting minor number*/
> + IIC_FSI_MAX_DEVS,
> + "iic-fsi");
> + if(rc)
> + {
> + IFLDe(1, "master alloc_chrdev_region failed: rc = %d\n", rc);
> + return rc;
> + }
> +
> + iic_fsi_class = class_create(THIS_MODULE, "iic-fsi");
> + if (IS_ERR(iic_fsi_class))
> + {
> + IFLDe(1, "class_create failed: rc=%ld",
> + PTR_ERR(iic_fsi_class));
> + goto exit_class_create;
> + }
> + /* Register this driver with the FSI infrastructure */
> + rc = fsi_driver_register(&i2c_drv);
> + if(rc)
> + {
> + IFLDe(1, "fsidrv_register failed: %d", rc);
> + goto exit_drv_register;
> + }
> +
> + printk("IIC FSI support loaded, ver. %s\n", iic_fsi_version);
> +
> + IEXIT(rc);
> + return rc;
> +
> +exit_drv_register:
> + class_destroy(iic_fsi_class);
> +exit_class_create:
> + unregister_chrdev_region(iic_devnum_start, IIC_FSI_MAX_DEVS);
> + IEXIT(rc);
> + return rc;
> +}
> +
> +static void __exit iic_fsi_exit(void)
> +{
> + IENTER();
> + IDBGd(0, "fisdrv_unregister()\n");
> + fsi_driver_unregister(&i2c_drv);
> + IDBGd(0, "unregister_chrdev_region()\n");
> + unregister_chrdev_region(iic_devnum_start, IIC_FSI_MAX_DEVS);
> + if(iic_fsi_class)
> + {
> + IDBGd(0, "class_destroy\n");
> + class_destroy(iic_fsi_class);
> + }
> + printk("IIC FSI support unloaded.\n");
> + IEXIT(0);
> +}
> +
> +module_init(iic_fsi_init);
> +module_exit(iic_fsi_exit);
> +
> +MODULE_AUTHOR("Eddie James <eajames at us.ibm.com>");
> +MODULE_DESCRIPTION("IIC FSI Driver");
> +MODULE_LICENSE("GPL");
> +
> diff --git a/drivers/fsi/i2c/iic-fsi.h b/drivers/fsi/i2c/iic-fsi.h
> new file mode 100644
> index 0000000..4decb2c
> --- /dev/null
> +++ b/drivers/fsi/i2c/iic-fsi.h
> @@ -0,0 +1,29 @@
> +/*
> + * Copyright (c) International Business Machines Corp., 2006
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
> + * the GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + */
> +
> +#ifndef IIC_FSI_H
> +#define IIC_FSI_H
> +
> +/*
> + * we don't know ahead of time how many minors will be needed as this is based
> + * on platform type and the possibility of sparsely populated FRU's on special
> + * systems so picking a safely large number
> + */
> +#define IIC_FSI_MAX_DEVS 1024
> +
> +#endif
> diff --git a/drivers/fsi/i2c/iic-int.h b/drivers/fsi/i2c/iic-int.h
> new file mode 100644
> index 0000000..545b2c3
> --- /dev/null
> +++ b/drivers/fsi/i2c/iic-int.h
> @@ -0,0 +1,80 @@
> +/*
> + * Copyright (c) International Business Machines Corp., 2006, 2012
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
> + * the GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + */
> +
> +#ifndef IIC_INT_H
> +#define IIC_INT_H
> +#include <linux/list.h>
> +#include <linux/spinlock.h>
> +#include <linux/fs.h>
> +#include <linux/kobject.h>
> +#include <linux/cdev.h>
> +#include <linux/device.h>
> +#include <linux/kdev_t.h>
> +#include <linux/wait.h>
> +#include <linux/i2cfsi.h>
> +#include <linux/semaphore.h>
> +#include <linux/fsi.h>
> +#include <asm/atomic.h>
> +
> +#define FSI_ENGID_I2C 0x7
> +#define FSI_ENGID_I2C_BB 0x17
> +
> +#ifdef FSI_I2C_DEBUG
> +#define IDBGs(num, msg, args...) printk(msg, ## args)
> +#define IDBGd(num, msg, args...) printk(msg, ## args)
> +#define IDBGf(num, msg, args...) printk(msg, ## args)
> +#define IDBGl(num, msg, args...) printk(msg, ## args)
> +#else
> +#define IDBGs(num, msg, args...)
> +#define IDBGd(num, msg, args...)
> +#define IDBGf(num, msg, args...)
> +#define IDBGl(num, msg, args...)
> +#endif
> +
> +#define IENTER()
> +#define IEXIT(RC)
> +
> +/* IFLDx traces will not get compiled out */
> +#define IFLDe(num, msg, args...)\
> + printk("ERR: "msg, ## args)
> +#define IFLDi(num, msg, args...)\
> + printk(msg, ## args)
> +
> +#ifdef FSI_I2C_DEBUG
> +#define IFLDs(num, msg, args...) printk(msg, ## args)
> +#define IFLDd(num, msg, args...) printk(msg, ## args)
> +#define IFLDf(num, msg, args...) printk(msg, ## args)
> +#define IFLDl(num, msg, args...) printk(msg, ## args)
> +#else
> +#define IFLDs(num, msg, args...)
> +#define IFLDd(num, msg, args...)
> +#define IFLDf(num, msg, args...)
> +#define IFLDl(num, msg, args...)
> +#endif
> +
> +struct iic_reg_access
> +{
> + int (*bus_readb)(iic_eng_t*, unsigned int, unsigned char*, iic_ffdc_t**);
> + int (*bus_readh)(iic_eng_t*, unsigned int, unsigned short*, iic_ffdc_t**);
> + int (*bus_readw)(iic_eng_t*, unsigned int, unsigned long*, iic_ffdc_t**);
> + int (*bus_writeb)(iic_eng_t*, unsigned int, unsigned char, iic_ffdc_t**);
> + int (*bus_writeh)(iic_eng_t*, unsigned int, unsigned short, iic_ffdc_t**);
> + int (*bus_writew)(iic_eng_t*, unsigned int, unsigned long, iic_ffdc_t**);
> +};
> +
> +#endif
>
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