linux/drivers/char/xilinx_hwicap/buffer_icap.c
Michal Simek 3c84dc7e79 char: xilinx_hwicap: Remove pointless local variables
Remove unused variables which generates these warnings:
[linux-4.10-rc5/drivers/char/xilinx_hwicap/buffer_icap.c:301]: (style)
Variable 'num_writes' is modified but its new value is never used.
[linux-4.10-rc5/drivers/char/xilinx_hwicap/buffer_icap.c:356]: (style)
Variable 'read_count' is modified but its new value is never used.

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:41:44 +01:00

362 lines
10 KiB
C

/*****************************************************************************
*
* Author: Xilinx, Inc.
*
* 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.
*
* XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
* AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
* SOLUTIONS FOR XILINX DEVICES. BY PROVIDING THIS DESIGN, CODE,
* OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
* APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
* THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
* AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
* FOR YOUR IMPLEMENTATION. XILINX EXPRESSLY DISCLAIMS ANY
* WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
* IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
* REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
* INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* (c) Copyright 2003-2008 Xilinx Inc.
* All rights reserved.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*****************************************************************************/
#include "buffer_icap.h"
/* Indicates how many bytes will fit in a buffer. (1 BRAM) */
#define XHI_MAX_BUFFER_BYTES 2048
#define XHI_MAX_BUFFER_INTS (XHI_MAX_BUFFER_BYTES >> 2)
/* File access and error constants */
#define XHI_DEVICE_READ_ERROR -1
#define XHI_DEVICE_WRITE_ERROR -2
#define XHI_BUFFER_OVERFLOW_ERROR -3
#define XHI_DEVICE_READ 0x1
#define XHI_DEVICE_WRITE 0x0
/* Constants for checking transfer status */
#define XHI_CYCLE_DONE 0
#define XHI_CYCLE_EXECUTING 1
/* buffer_icap register offsets */
/* Size of transfer, read & write */
#define XHI_SIZE_REG_OFFSET 0x800L
/* offset into bram, read & write */
#define XHI_BRAM_OFFSET_REG_OFFSET 0x804L
/* Read not Configure, direction of transfer. Write only */
#define XHI_RNC_REG_OFFSET 0x808L
/* Indicates transfer complete. Read only */
#define XHI_STATUS_REG_OFFSET 0x80CL
/* Constants for setting the RNC register */
#define XHI_CONFIGURE 0x0UL
#define XHI_READBACK 0x1UL
/* Constants for the Done register */
#define XHI_NOT_FINISHED 0x0UL
#define XHI_FINISHED 0x1UL
#define XHI_BUFFER_START 0
/**
* buffer_icap_get_status - Get the contents of the status register.
* @drvdata: a pointer to the drvdata.
*
* The status register contains the ICAP status and the done bit.
*
* D8 - cfgerr
* D7 - dalign
* D6 - rip
* D5 - in_abort_l
* D4 - Always 1
* D3 - Always 1
* D2 - Always 1
* D1 - Always 1
* D0 - Done bit
**/
u32 buffer_icap_get_status(struct hwicap_drvdata *drvdata)
{
return in_be32(drvdata->base_address + XHI_STATUS_REG_OFFSET);
}
/**
* buffer_icap_get_bram - Reads data from the storage buffer bram.
* @base_address: contains the base address of the component.
* @offset: The word offset from which the data should be read.
*
* A bram is used as a configuration memory cache. One frame of data can
* be stored in this "storage buffer".
**/
static inline u32 buffer_icap_get_bram(void __iomem *base_address,
u32 offset)
{
return in_be32(base_address + (offset << 2));
}
/**
* buffer_icap_busy - Return true if the icap device is busy
* @base_address: is the base address of the device
*
* The queries the low order bit of the status register, which
* indicates whether the current configuration or readback operation
* has completed.
**/
static inline bool buffer_icap_busy(void __iomem *base_address)
{
u32 status = in_be32(base_address + XHI_STATUS_REG_OFFSET);
return (status & 1) == XHI_NOT_FINISHED;
}
/**
* buffer_icap_set_size - Set the size register.
* @base_address: is the base address of the device
* @data: The size in bytes.
*
* The size register holds the number of 8 bit bytes to transfer between
* bram and the icap (or icap to bram).
**/
static inline void buffer_icap_set_size(void __iomem *base_address,
u32 data)
{
out_be32(base_address + XHI_SIZE_REG_OFFSET, data);
}
/**
* buffer_icap_set_offset - Set the bram offset register.
* @base_address: contains the base address of the device.
* @data: is the value to be written to the data register.
*
* The bram offset register holds the starting bram address to transfer
* data from during configuration or write data to during readback.
**/
static inline void buffer_icap_set_offset(void __iomem *base_address,
u32 data)
{
out_be32(base_address + XHI_BRAM_OFFSET_REG_OFFSET, data);
}
/**
* buffer_icap_set_rnc - Set the RNC (Readback not Configure) register.
* @base_address: contains the base address of the device.
* @data: is the value to be written to the data register.
*
* The RNC register determines the direction of the data transfer. It
* controls whether a configuration or readback take place. Writing to
* this register initiates the transfer. A value of 1 initiates a
* readback while writing a value of 0 initiates a configuration.
**/
static inline void buffer_icap_set_rnc(void __iomem *base_address,
u32 data)
{
out_be32(base_address + XHI_RNC_REG_OFFSET, data);
}
/**
* buffer_icap_set_bram - Write data to the storage buffer bram.
* @base_address: contains the base address of the component.
* @offset: The word offset at which the data should be written.
* @data: The value to be written to the bram offset.
*
* A bram is used as a configuration memory cache. One frame of data can
* be stored in this "storage buffer".
**/
static inline void buffer_icap_set_bram(void __iomem *base_address,
u32 offset, u32 data)
{
out_be32(base_address + (offset << 2), data);
}
/**
* buffer_icap_device_read - Transfer bytes from ICAP to the storage buffer.
* @drvdata: a pointer to the drvdata.
* @offset: The storage buffer start address.
* @count: The number of words (32 bit) to read from the
* device (ICAP).
**/
static int buffer_icap_device_read(struct hwicap_drvdata *drvdata,
u32 offset, u32 count)
{
s32 retries = 0;
void __iomem *base_address = drvdata->base_address;
if (buffer_icap_busy(base_address))
return -EBUSY;
if ((offset + count) > XHI_MAX_BUFFER_INTS)
return -EINVAL;
/* setSize count*4 to get bytes. */
buffer_icap_set_size(base_address, (count << 2));
buffer_icap_set_offset(base_address, offset);
buffer_icap_set_rnc(base_address, XHI_READBACK);
while (buffer_icap_busy(base_address)) {
retries++;
if (retries > XHI_MAX_RETRIES)
return -EBUSY;
}
return 0;
};
/**
* buffer_icap_device_write - Transfer bytes from ICAP to the storage buffer.
* @drvdata: a pointer to the drvdata.
* @offset: The storage buffer start address.
* @count: The number of words (32 bit) to read from the
* device (ICAP).
**/
static int buffer_icap_device_write(struct hwicap_drvdata *drvdata,
u32 offset, u32 count)
{
s32 retries = 0;
void __iomem *base_address = drvdata->base_address;
if (buffer_icap_busy(base_address))
return -EBUSY;
if ((offset + count) > XHI_MAX_BUFFER_INTS)
return -EINVAL;
/* setSize count*4 to get bytes. */
buffer_icap_set_size(base_address, count << 2);
buffer_icap_set_offset(base_address, offset);
buffer_icap_set_rnc(base_address, XHI_CONFIGURE);
while (buffer_icap_busy(base_address)) {
retries++;
if (retries > XHI_MAX_RETRIES)
return -EBUSY;
}
return 0;
};
/**
* buffer_icap_reset - Reset the logic of the icap device.
* @drvdata: a pointer to the drvdata.
*
* Writing to the status register resets the ICAP logic in an internal
* version of the core. For the version of the core published in EDK,
* this is a noop.
**/
void buffer_icap_reset(struct hwicap_drvdata *drvdata)
{
out_be32(drvdata->base_address + XHI_STATUS_REG_OFFSET, 0xFEFE);
}
/**
* buffer_icap_set_configuration - Load a partial bitstream from system memory.
* @drvdata: a pointer to the drvdata.
* @data: Kernel address of the partial bitstream.
* @size: the size of the partial bitstream in 32 bit words.
**/
int buffer_icap_set_configuration(struct hwicap_drvdata *drvdata, u32 *data,
u32 size)
{
int status;
s32 buffer_count = 0;
bool dirty = false;
u32 i;
void __iomem *base_address = drvdata->base_address;
/* Loop through all the data */
for (i = 0, buffer_count = 0; i < size; i++) {
/* Copy data to bram */
buffer_icap_set_bram(base_address, buffer_count, data[i]);
dirty = true;
if (buffer_count < XHI_MAX_BUFFER_INTS - 1) {
buffer_count++;
continue;
}
/* Write data to ICAP */
status = buffer_icap_device_write(
drvdata,
XHI_BUFFER_START,
XHI_MAX_BUFFER_INTS);
if (status != 0) {
/* abort. */
buffer_icap_reset(drvdata);
return status;
}
buffer_count = 0;
dirty = false;
}
/* Write unwritten data to ICAP */
if (dirty) {
/* Write data to ICAP */
status = buffer_icap_device_write(drvdata, XHI_BUFFER_START,
buffer_count);
if (status != 0) {
/* abort. */
buffer_icap_reset(drvdata);
}
return status;
}
return 0;
};
/**
* buffer_icap_get_configuration - Read configuration data from the device.
* @drvdata: a pointer to the drvdata.
* @data: Address of the data representing the partial bitstream
* @size: the size of the partial bitstream in 32 bit words.
**/
int buffer_icap_get_configuration(struct hwicap_drvdata *drvdata, u32 *data,
u32 size)
{
int status;
s32 buffer_count = 0;
u32 i;
void __iomem *base_address = drvdata->base_address;
/* Loop through all the data */
for (i = 0, buffer_count = XHI_MAX_BUFFER_INTS; i < size; i++) {
if (buffer_count == XHI_MAX_BUFFER_INTS) {
u32 words_remaining = size - i;
u32 words_to_read =
words_remaining <
XHI_MAX_BUFFER_INTS ? words_remaining :
XHI_MAX_BUFFER_INTS;
/* Read data from ICAP */
status = buffer_icap_device_read(
drvdata,
XHI_BUFFER_START,
words_to_read);
if (status != 0) {
/* abort. */
buffer_icap_reset(drvdata);
return status;
}
buffer_count = 0;
}
/* Copy data from bram */
data[i] = buffer_icap_get_bram(base_address, buffer_count);
buffer_count++;
}
return 0;
};