hwmon: occ: Add I2C transport implementation for SCOM operations
PATCH 3/7 hwmon: occ: Add I2C transport implementation for SCOM operations
From: "Edward A. James" <[email protected]>
Add functions to send SCOM operations over I2C bus. The BMC can communicate with the Power8 host processor over I2C, but needs to use SCOM operations in order to access the OCC register space.
Signed-off-by Edward A. James <[email protected]>
Signed-off-by Andrew Jeffery <[email protected]>
--- drivers/hwmon/occ/occ_scom_i2c.c | 67 ++++++++++++++++++++++++++++++++++++++++ drivers/hwmon/occ/occ_scom_i2c.h | 26 ++++++++++++++++ 2 files changed, 93 insertions(+) create mode 100644 drivers/hwmon/occ/occ_scom_i2c.c create mode 100644 drivers/hwmon/occ/occ_scom_i2c.h
drivers/hwmon/occ/occ_scom_i2c.c new file +67 -0
@@ -0,0 +1,67 @@ +/* +* occ_scom_i2c.c - hwmon OCC driver +* +* This file contains the functions for performing SCOM operations over I2C bus +* to access the OCC. +* +* Copyright 2016 IBM Corp. +* +* 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. +*/ + +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include "scom.h" +#include "occ_scom_i2c.h" + +int occ_i2c_getscom (void *bus,u32 address,u8 *data) +{ +ssize_t rc; +u64 buf; +struct i2c_client *client = bus; + + rc =i2c_master_send (client, (const char *)&address,sizeof (u32)); +if (rc !=sizeof (u32)) +return -EIO ; + + rc =i2c_master_recv (client, (char *)&buf,sizeof (u64)); +if (rc !=sizeof (u64)) +return -EIO ; + + *((u64 *)data) =be64_to_cpu (buf); + +return 0 ; +} +EXPORT_SYMBOL (occ_i2c_getscom); + +int occ_i2c_putscom (void *bus,u32 address,u32 data0,u32 data1) +{ +u32 buf[3 ]; +ssize_t rc; +struct i2c_client *client = bus; + + buf[0 ] = address; + buf[1 ] = data1; + buf[2 ] = data0; + + rc =i2c_master_send (client, (const char *)buf,sizeof (u32) *3 ); +if (rc !=sizeof (u32) *3 ) +return -EIO ; + +return 0 ; +} +EXPORT_SYMBOL (occ_i2c_putscom); + +MODULE_AUTHOR ("Eddie James <[email protected]>" ); +MODULE_DESCRIPTION ("I2C OCC SCOM transport" ); +MODULE_LICENSE ("GPL" );
drivers/hwmon/occ/occ_scom_i2c.h new file +26 -0
@@ -0,0 +1,26 @@ +/* +* occ_scom_i2c.h - hwmon OCC driver +* +* This file contains function protoypes for peforming SCOM operations over I2C +* bus to access the OCC. +* +* Copyright 2016 IBM Corp. +* +* 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. +*/ + +#ifndef __OCC_SCOM_I2C_H__ +#define __OCC_SCOM_I2C_H__ + +int occ_i2c_getscom (void *bus,u32 address,u8 *data); +int occ_i2c_putscom (void *bus,u32 address,u32 data0,u32 data1); + +#endif /* __OCC_SCOM_I2C_H__ */
Signature · 1 line
1.9.1
Hi Eddie,
Some minor comments below.
Quoted 52 lines · On Fri, 2016-12-16 at 14:35 -0600, [email protected] wrote:
Quoted 1 line
From: "Edward A. James" <[email protected]>
Add functions to send SCOM operations over I2C bus. The BMC can communicate with the Power8 host processor over I2C, but needs to use SCOM operations in order to access the OCC register space.
Quoted 2 lines
Signed-off-by Edward A. James <[email protected]>Signed-off-by Andrew Jeffery <[email protected]>---
drivers/hwmon/occ/occ_scom_i2c.c | 67 ++++++++++++++++++++++++++++++++++++++++drivers/hwmon/occ/occ_scom_i2c.h| 26 ++++++++++++++++2 files changed, 93 insertions(+)create mode 100644
drivers/hwmon/occ/occ_scom_i2c.ccreate mode 100644drivers/hwmon/occ/occ_scom_i2c.hdrivers/hwmon/occ/occ_scom_i2c.c new file +28
-0@@ -0,0 +1,67 @@ +/* +* occ_scom_i2c.c - hwmon OCC driver +* +* This file contains the functions for performing SCOM operations over I2C bus +* to access the OCC. +* +* Copyright 2016 IBM Corp. +* +* 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. +*/ + +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include "scom.h" +#include "occ_scom_i2c.h" + +int occ_i2c_getscom (void *bus,u32 address,u8 *data) +{Quoted 3 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +3
-0+ssize_t rc; +u64 buf; +struct i2c_client *client = bus;
drivers/hwmon/occ/occ_scom_i2c.c
Quoted 2 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +2
-0+ + rc =i2c_master_send (client, (const char *)&address,sizeof (u32));
From the documentation: "Returns negative errno, or else the number of bytes read"
drivers/hwmon/occ/occ_scom_i2c.c
Quoted 2 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +2
-0+if (rc !=sizeof (u32)) +return -EIO ;
So what we should probably be doing here is:
if (rc >= 0 && rc != sizeof(u32))
return -EIO;
else
return rc;drivers/hwmon/occ/occ_scom_i2c.c
Quoted 4 lines
+
Quoted 2 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +2
-0+ rc =i2c_master_recv (client, (char *)&buf,sizeof (u64)); +if (rc !=sizeof (u64))drivers/hwmon/occ/occ_scom_i2c.c new file +1
-0+return -EIO ;
As above.
drivers/hwmon/occ/occ_scom_i2c.c
Quoted 2 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +2
-0+ + *((u64 *)data) =be64_to_cpu (buf);
Please change the getscom prototypes to take a u64 *. That way we can get compiler warnings if caller code is broken.
Quoted 17 lines
+
Quoted 1 line
(quoted diff) +1
-0+ return 0;drivers/hwmon/occ/occ_scom_i2c.c new file +5
-0+} +EXPORT_SYMBOL (occ_i2c_getscom); + +int occ_i2c_putscom (void *bus,u32 address,u32 data0,u32 data1) +{drivers/hwmon/occ/occ_scom_i2c.c line 51
Quoted 3 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +3
-0+u32 buf[3 ]; +ssize_t rc; +struct i2c_client *client = bus;+
drivers/hwmon/occ/occ_scom_i2c.c line 55
Quoted 3 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +3
-0+ buf[0 ] = address; + buf[1 ] = data1; + buf[2 ] = data0;+
Quoted 2 lines
drivers/hwmon/occ/occ_scom_i2c.c new file +2
-0+ rc =i2c_master_send (client, (const char *)buf,sizeof (u32) *3 ); +if (rc !=sizeof (u32) *3 )
drivers/hwmon/occ/occ_scom_i2c.c
Quoted 1 line
drivers/hwmon/occ/occ_scom_i2c.c new file +1
-0+return -EIO ;
See comment on error handling above.
Quoted 27 lines
+
Quoted 1 line
(quoted diff) +1
-0+ return 0;drivers/hwmon/occ/occ_scom_i2c.c new file +3
-0+} +EXPORT_SYMBOL (occ_i2c_putscom); +Quoted 1 line
+MODULE_AUTHOR("Eddie James <[email protected]>");
drivers/hwmon/occ/occ_scom_i2c.c new file +2
-0+MODULE_DESCRIPTION ("I2C OCC SCOM transport" ); +MODULE_LICENSE ("GPL" );drivers/hwmon/occ/occ_scom_i2c.h new file +13
-0@@ -0,0 +1,26 @@ +/* +* occ_scom_i2c.h - hwmon OCC driver +* +* This file contains function protoypes for peforming SCOM operations over I2C +* bus to access the OCC. +* +* Copyright 2016 IBM Corp. +* +* 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. +*
drivers/hwmon/occ/occ_scom_i2c.h line 23
Quoted 10 lines
drivers/hwmon/occ/occ_scom_i2c.h new file +10
-0+* 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. +*/ + +#ifndef __OCC_SCOM_I2C_H__ +#define __OCC_SCOM_I2C_H__ + +int occ_i2c_getscom (void *bus,u32 address,u8 *data);
so "u64 *data" here, and in scom.h.
drivers/hwmon/occ/occ_scom_i2c.h line 26
Quoted 3 lines
drivers/hwmon/occ/occ_scom_i2c.h new file +3
-0+int occ_i2c_putscom (void *bus,u32 address,u32 data0,u32 data1); + +#endif /* __OCC_SCOM_I2C_H__ */
Cheers,
Andrew