linux/drivers/char/xilinx_hwicap/fifo_icap.c

394 lines
12 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 2007-2008 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 "fifo_icap.h"
/* Register offsets for the XHwIcap device. */
#define XHI_GIER_OFFSET 0x1C /* Device Global Interrupt Enable Reg */
#define XHI_IPISR_OFFSET 0x20 /* Interrupt Status Register */
#define XHI_IPIER_OFFSET 0x28 /* Interrupt Enable Register */
#define XHI_WF_OFFSET 0x100 /* Write FIFO */
#define XHI_RF_OFFSET 0x104 /* Read FIFO */
#define XHI_SZ_OFFSET 0x108 /* Size Register */
#define XHI_CR_OFFSET 0x10C /* Control Register */
#define XHI_SR_OFFSET 0x110 /* Status Register */
#define XHI_WFV_OFFSET 0x114 /* Write FIFO Vacancy Register */
#define XHI_RFO_OFFSET 0x118 /* Read FIFO Occupancy Register */
/* Device Global Interrupt Enable Register (GIER) bit definitions */
#define XHI_GIER_GIE_MASK 0x80000000 /* Global Interrupt enable Mask */
/**
* HwIcap Device Interrupt Status/Enable Registers
*
* Interrupt Status Register (IPISR) : This register holds the
* interrupt status flags for the device. These bits are toggle on
* write.
*
* Interrupt Enable Register (IPIER) : This register is used to enable
* interrupt sources for the device.
* Writing a '1' to a bit enables the corresponding interrupt.
* Writing a '0' to a bit disables the corresponding interrupt.
*
* IPISR/IPIER registers have the same bit definitions and are only defined
* once.
*/
#define XHI_IPIXR_RFULL_MASK 0x00000008 /* Read FIFO Full */
#define XHI_IPIXR_WEMPTY_MASK 0x00000004 /* Write FIFO Empty */
#define XHI_IPIXR_RDP_MASK 0x00000002 /* Read FIFO half full */
#define XHI_IPIXR_WRP_MASK 0x00000001 /* Write FIFO half full */
#define XHI_IPIXR_ALL_MASK 0x0000000F /* Mask of all interrupts */
/* Control Register (CR) */
#define XHI_CR_SW_RESET_MASK 0x00000008 /* SW Reset Mask */
#define XHI_CR_FIFO_CLR_MASK 0x00000004 /* FIFO Clear Mask */
#define XHI_CR_READ_MASK 0x00000002 /* Read from ICAP to FIFO */
#define XHI_CR_WRITE_MASK 0x00000001 /* Write from FIFO to ICAP */
#define XHI_WFO_MAX_VACANCY 1024 /* Max Write FIFO Vacancy, in words */
#define XHI_RFO_MAX_OCCUPANCY 256 /* Max Read FIFO Occupancy, in words */
/* The maximum amount we can request from fifo_icap_get_configuration
at once, in bytes. */
#define XHI_MAX_READ_TRANSACTION_WORDS 0xFFF
/**
* fifo_icap_fifo_write - Write data to the write FIFO.
* @drvdata: a pointer to the drvdata.
* @data: the 32-bit value to be written to the FIFO.
*
* This function will silently fail if the fifo is full.
**/
static inline void fifo_icap_fifo_write(struct hwicap_drvdata *drvdata,
u32 data)
{
dev_dbg(drvdata->dev, "fifo_write: %x\n", data);
out_be32(drvdata->base_address + XHI_WF_OFFSET, data);
}
/**
* fifo_icap_fifo_read - Read data from the Read FIFO.
* @drvdata: a pointer to the drvdata.
*
* This function will silently fail if the fifo is empty.
**/
static inline u32 fifo_icap_fifo_read(struct hwicap_drvdata *drvdata)
{
u32 data = in_be32(drvdata->base_address + XHI_RF_OFFSET);
dev_dbg(drvdata->dev, "fifo_read: %x\n", data);
return data;
}
/**
* fifo_icap_set_read_size - Set the the size register.
* @drvdata: a pointer to the drvdata.
* @data: the size of the following read transaction, in words.
**/
static inline void fifo_icap_set_read_size(struct hwicap_drvdata *drvdata,
u32 data)
{
out_be32(drvdata->base_address + XHI_SZ_OFFSET, data);
}
/**
* fifo_icap_start_config - Initiate a configuration (write) to the device.
* @drvdata: a pointer to the drvdata.
**/
static inline void fifo_icap_start_config(struct hwicap_drvdata *drvdata)
{
out_be32(drvdata->base_address + XHI_CR_OFFSET, XHI_CR_WRITE_MASK);
dev_dbg(drvdata->dev, "configuration started\n");
}
/**
* fifo_icap_start_readback - Initiate a readback from the device.
* @drvdata: a pointer to the drvdata.
**/
static inline void fifo_icap_start_readback(struct hwicap_drvdata *drvdata)
{
out_be32(drvdata->base_address + XHI_CR_OFFSET, XHI_CR_READ_MASK);
dev_dbg(drvdata->dev, "readback started\n");
}
/**
* fifo_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 fifo_icap_get_status(struct hwicap_drvdata *drvdata)
{
u32 status = in_be32(drvdata->base_address + XHI_SR_OFFSET);
dev_dbg(drvdata->dev, "Getting status = %x\n", status);
return status;
}
/**
* fifo_icap_busy - Return true if the ICAP is still processing a transaction.
* @drvdata: a pointer to the drvdata.
**/
static inline u32 fifo_icap_busy(struct hwicap_drvdata *drvdata)
{
u32 status = in_be32(drvdata->base_address + XHI_SR_OFFSET);
return (status & XHI_SR_DONE_MASK) ? 0 : 1;
}
/**
* fifo_icap_write_fifo_vacancy - Query the write fifo available space.
* @drvdata: a pointer to the drvdata.
*
* Return the number of words that can be safely pushed into the write fifo.
**/
static inline u32 fifo_icap_write_fifo_vacancy(
struct hwicap_drvdata *drvdata)
{
return in_be32(drvdata->base_address + XHI_WFV_OFFSET);
}
/**
* fifo_icap_read_fifo_occupancy - Query the read fifo available data.
* @drvdata: a pointer to the drvdata.
*
* Return the number of words that can be safely read from the read fifo.
**/
static inline u32 fifo_icap_read_fifo_occupancy(
struct hwicap_drvdata *drvdata)
{
return in_be32(drvdata->base_address + XHI_RFO_OFFSET);
}
/**
* fifo_icap_set_configuration - Send configuration data to the ICAP.
* @drvdata: a pointer to the drvdata.
* @frame_buffer: a pointer to the data to be written to the
* ICAP device.
* @num_words: the number of words (32 bit) to write to the ICAP
* device.
* This function writes the given user data to the Write FIFO in
* polled mode and starts the transfer of the data to
* the ICAP device.
**/
int fifo_icap_set_configuration(struct hwicap_drvdata *drvdata,
u32 *frame_buffer, u32 num_words)
{
u32 write_fifo_vacancy = 0;
u32 retries = 0;
u32 remaining_words;
dev_dbg(drvdata->dev, "fifo_set_configuration\n");
/*
* Check if the ICAP device is Busy with the last Read/Write
*/
if (fifo_icap_busy(drvdata))
return -EBUSY;
/*
* Set up the buffer pointer and the words to be transferred.
*/
remaining_words = num_words;
while (remaining_words > 0) {
/*
* Wait until we have some data in the fifo.
*/
while (write_fifo_vacancy == 0) {
write_fifo_vacancy =
fifo_icap_write_fifo_vacancy(drvdata);
retries++;
if (retries > XHI_MAX_RETRIES)
return -EIO;
}
/*
* Write data into the Write FIFO.
*/
while ((write_fifo_vacancy != 0) &&
(remaining_words > 0)) {
fifo_icap_fifo_write(drvdata, *frame_buffer);
remaining_words--;
write_fifo_vacancy--;
frame_buffer++;
}
/* Start pushing whatever is in the FIFO into the ICAP. */
fifo_icap_start_config(drvdata);
}
/* Wait until the write has finished. */
while (fifo_icap_busy(drvdata)) {
retries++;
if (retries > XHI_MAX_RETRIES)
break;
}
dev_dbg(drvdata->dev, "done fifo_set_configuration\n");
/*
* If the requested number of words have not been read from
* the device then indicate failure.
*/
if (remaining_words != 0)
return -EIO;
return 0;
}
/**
* fifo_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.
*
* This function reads the specified number of words from the ICAP device in
* the polled mode.
*/
int fifo_icap_get_configuration(struct hwicap_drvdata *drvdata,
u32 *frame_buffer, u32 num_words)
{
u32 read_fifo_occupancy = 0;
u32 retries = 0;
u32 *data = frame_buffer;
u32 remaining_words;
u32 words_to_read;
dev_dbg(drvdata->dev, "fifo_get_configuration\n");
/*
* Check if the ICAP device is Busy with the last Write/Read
*/
if (fifo_icap_busy(drvdata))
return -EBUSY;
remaining_words = num_words;
while (remaining_words > 0) {
words_to_read = remaining_words;
/* The hardware has a limit on the number of words
that can be read at one time. */
if (words_to_read > XHI_MAX_READ_TRANSACTION_WORDS)
words_to_read = XHI_MAX_READ_TRANSACTION_WORDS;
remaining_words -= words_to_read;
fifo_icap_set_read_size(drvdata, words_to_read);
fifo_icap_start_readback(drvdata);
while (words_to_read > 0) {
/* Wait until we have some data in the fifo. */
while (read_fifo_occupancy == 0) {
read_fifo_occupancy =
fifo_icap_read_fifo_occupancy(drvdata);
retries++;
if (retries > XHI_MAX_RETRIES)
return -EIO;
}
if (read_fifo_occupancy > words_to_read)
read_fifo_occupancy = words_to_read;
words_to_read -= read_fifo_occupancy;
/* Read the data from the Read FIFO. */
while (read_fifo_occupancy != 0) {
*data++ = fifo_icap_fifo_read(drvdata);
read_fifo_occupancy--;
}
}
}
dev_dbg(drvdata->dev, "done fifo_get_configuration\n");
return 0;
}
/**
* buffer_icap_reset - Reset the logic of the icap device.
* @drvdata: a pointer to the drvdata.
*
* This function forces the software reset of the complete HWICAP device.
* All the registers will return to the default value and the FIFO is also
* flushed as a part of this software reset.
*/
void fifo_icap_reset(struct hwicap_drvdata *drvdata)
{
u32 reg_data;
/*
* Reset the device by setting/clearing the RESET bit in the
* Control Register.
*/
reg_data = in_be32(drvdata->base_address + XHI_CR_OFFSET);
out_be32(drvdata->base_address + XHI_CR_OFFSET,
reg_data | XHI_CR_SW_RESET_MASK);
out_be32(drvdata->base_address + XHI_CR_OFFSET,
reg_data & (~XHI_CR_SW_RESET_MASK));
}
/**
* fifo_icap_flush_fifo - This function flushes the FIFOs in the device.
* @drvdata: a pointer to the drvdata.
*/
void fifo_icap_flush_fifo(struct hwicap_drvdata *drvdata)
{
u32 reg_data;
/*
* Flush the FIFO by setting/clearing the FIFO Clear bit in the
* Control Register.
*/
reg_data = in_be32(drvdata->base_address + XHI_CR_OFFSET);
out_be32(drvdata->base_address + XHI_CR_OFFSET,
reg_data | XHI_CR_FIFO_CLR_MASK);
out_be32(drvdata->base_address + XHI_CR_OFFSET,
reg_data & (~XHI_CR_FIFO_CLR_MASK));
}