Committer: Michael Beasley <mike@snafu.setup>

[mikesnafu-overlay.git] / drivers / char / xilinx_hwicap / fifo_icap.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.
 *
 *     Xilinx products are not intended for use in life support appliances,
 *     devices, or systems. Use in such applications is expressly prohibited.
 *
 *     (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 */

/* Status Register (SR) */
#define XHI_SR_CFGERR_N_MASK 0x00000100 /* Config Error Mask */
#define XHI_SR_DALIGN_MASK 0x00000080 /* Data Alignment Mask */
#define XHI_SR_RIP_MASK 0x00000040 /* Read back Mask */
#define XHI_SR_IN_ABORT_N_MASK 0x00000020 /* Select Map Abort Mask */
#define XHI_SR_DONE_MASK 0x00000001 /* Done bit Mask  */


#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_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);
        dev_dbg(drvdata->dev, "Getting status = %x\n", status);
        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));
}