[POWERPC] Xilinx: hwicap driver

This includes code for new fifo-based xps_hwicap in addition to the
older opb_hwicap, which has a significantly different interface.  The
common code between the two drivers is largely shared.

Significant differences exists between this driver and what is
supported in the EDK drivers.  In particular, most of the
architecture-specific code for reconfiguring individual FPGA resources
has been removed.  This functionality is likely better provided in a
user-space support library.  In addition, read and write access is
supported.  In addition, although the xps_hwicap cores support
interrupt-driver mode, this driver only supports polled operation, in
order to make the code simpler, and since the interrupt processing
overhead is likely to slow down the throughput under Linux.

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 380 insertions, 0 deletions

diff --git a/drivers/char/xilinx_hwicap/buffer_icap.c b/drivers/char/xilinx_hwicap/buffer_icap.c
new file mode 100644
index 000000000000..dfea2bde162b
--- /dev/null
+++ b/drivers/char/xilinx_hwicap/buffer_icap.c
@@ -0,0 +1,380 @@
+/*****************************************************************************
+ *
+ *     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 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.
+ * @parameter base_address: is the base address of the device
+ *
+ * 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
+ **/
+static inline u32 buffer_icap_get_status(void __iomem *base_address)
+{
+	return in_be32(base_address + XHI_STATUS_REG_OFFSET);
+}
+
+/**
+ * buffer_icap_get_bram: Reads data from the storage buffer bram.
+ * @parameter base_address: contains the base address of the component.
+ * @parameter 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
+ * @parameter 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)
+{
+	return (buffer_icap_get_status(base_address) & 1) == XHI_NOT_FINISHED;
+}
+
+/**
+ * buffer_icap_busy: Return true if the icap device is not busy
+ * @parameter 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_done(void __iomem *base_address)
+{
+	return (buffer_icap_get_status(base_address) & 1) == XHI_FINISHED;
+}
+
+/**
+ * buffer_icap_set_size: Set the size register.
+ * @parameter base_address: is the base address of the device
+ * @parameter 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_mSetoffsetReg: Set the bram offset register.
+ * @parameter base_address: contains the base address of the device.
+ * @parameter 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.
+ * @parameter base_address: contains the base address of the device.
+ * @parameter 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.
+ * @parameter base_address: contains the base address of the component.
+ * @parameter offset: The word offset at which the data should be written.
+ * @parameter 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.
+ * @parameter drvdata: a pointer to the drvdata.
+ * @parameter offset: The storage buffer start address.
+ * @parameter 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.
+ * @parameter drvdata: a pointer to the drvdata.
+ * @parameter offset: The storage buffer start address.
+ * @parameter 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.
+ * @parameter 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.
+ * @parameter drvdata: a pointer to the drvdata.
+ * @parameter data: Kernel address of the partial bitstream.
+ * @parameter 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;
+	s32 num_writes = 0;
+	bool dirty = 0;
+	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 = 1;
+
+		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;
+		num_writes++;
+		dirty = 0;
+	}
+
+	/* 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.
+ * @parameter drvdata: a pointer to the drvdata.
+ * @parameter data: Address of the data representing the partial bitstream
+ * @parameter 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;
+	s32 read_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;
+			read_count++;
+		}
+
+		/* Copy data from bram */
+		data[i] = buffer_icap_get_bram(base_address, buffer_count);
+		buffer_count++;
+	}
+
+	return 0;
+};