--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+/***************************************************************************
+ * GPIB Driver for Fluke cda devices. Basically, its a driver for a (bugfixed)
+ * cb7210 connected to channel 0 of a pl330 dma controller.
+ * Author: Frank Mori Hess <fmh6jj@gmail.com>
+ * copyright: (C) 2006, 2010, 2015 Fluke Corporation
+ ***************************************************************************/
+
+#include "fluke_gpib.h"
+
+#include "gpibP.h"
+#include <linux/dma-mapping.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+MODULE_LICENSE("GPL");
+
+static int fluke_attach_holdoff_all(gpib_board_t *board, const gpib_board_config_t *config);
+static int fluke_attach_holdoff_end(gpib_board_t *board, const gpib_board_config_t *config);
+static void fluke_detach(gpib_board_t *board);
+static int fluke_config_dma(gpib_board_t *board, int output);
+static irqreturn_t fluke_gpib_internal_interrupt(gpib_board_t *board);
+
+static struct platform_device *fluke_gpib_pdev;
+
+static uint8_t fluke_locking_read_byte(struct nec7210_priv *nec_priv, unsigned int register_number)
+{
+ u8 retval;
+ unsigned long flags;
+
+ spin_lock_irqsave(&nec_priv->register_page_lock, flags);
+ retval = fluke_read_byte_nolock(nec_priv, register_number);
+ spin_unlock_irqrestore(&nec_priv->register_page_lock, flags);
+ return retval;
+}
+
+static void fluke_locking_write_byte(struct nec7210_priv *nec_priv, uint8_t byte,
+ unsigned int register_number)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&nec_priv->register_page_lock, flags);
+ fluke_write_byte_nolock(nec_priv, byte, register_number);
+ spin_unlock_irqrestore(&nec_priv->register_page_lock, flags);
+}
+
+// wrappers for interface functions
+static int fluke_read(gpib_board_t *board, uint8_t *buffer, size_t length, int *end,
+ size_t *bytes_read)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_read(board, &priv->nec7210_priv, buffer, length, end, bytes_read);
+}
+
+static int fluke_write(gpib_board_t *board, uint8_t *buffer, size_t length,
+ int send_eoi, size_t *bytes_written)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_write(board, &priv->nec7210_priv, buffer, length, send_eoi, bytes_written);
+}
+
+static int fluke_command(gpib_board_t *board, uint8_t *buffer, size_t length, size_t *bytes_written)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_command(board, &priv->nec7210_priv, buffer, length, bytes_written);
+}
+
+static int fluke_take_control(gpib_board_t *board, int synchronous)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_take_control(board, &priv->nec7210_priv, synchronous);
+}
+
+static int fluke_go_to_standby(gpib_board_t *board)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_go_to_standby(board, &priv->nec7210_priv);
+}
+
+static void fluke_request_system_control(gpib_board_t *board, int request_control)
+{
+ struct fluke_priv *priv = board->private_data;
+ struct nec7210_priv *nec_priv = &priv->nec7210_priv;
+
+ nec7210_request_system_control(board, nec_priv, request_control);
+}
+
+static void fluke_interface_clear(gpib_board_t *board, int assert)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ nec7210_interface_clear(board, &priv->nec7210_priv, assert);
+}
+
+static void fluke_remote_enable(gpib_board_t *board, int enable)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ nec7210_remote_enable(board, &priv->nec7210_priv, enable);
+}
+
+static int fluke_enable_eos(gpib_board_t *board, uint8_t eos_byte, int compare_8_bits)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_enable_eos(board, &priv->nec7210_priv, eos_byte, compare_8_bits);
+}
+
+static void fluke_disable_eos(gpib_board_t *board)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ nec7210_disable_eos(board, &priv->nec7210_priv);
+}
+
+static unsigned int fluke_update_status(gpib_board_t *board, unsigned int clear_mask)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_update_status(board, &priv->nec7210_priv, clear_mask);
+}
+
+static int fluke_primary_address(gpib_board_t *board, unsigned int address)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_primary_address(board, &priv->nec7210_priv, address);
+}
+
+static int fluke_secondary_address(gpib_board_t *board, unsigned int address, int enable)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_secondary_address(board, &priv->nec7210_priv, address, enable);
+}
+
+static int fluke_parallel_poll(gpib_board_t *board, uint8_t *result)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_parallel_poll(board, &priv->nec7210_priv, result);
+}
+
+static void fluke_parallel_poll_configure(gpib_board_t *board, uint8_t configuration)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ nec7210_parallel_poll_configure(board, &priv->nec7210_priv, configuration);
+}
+
+static void fluke_parallel_poll_response(gpib_board_t *board, int ist)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ nec7210_parallel_poll_response(board, &priv->nec7210_priv, ist);
+}
+
+static void fluke_serial_poll_response(gpib_board_t *board, uint8_t status)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ nec7210_serial_poll_response(board, &priv->nec7210_priv, status);
+}
+
+static uint8_t fluke_serial_poll_status(gpib_board_t *board)
+{
+ struct fluke_priv *priv = board->private_data;
+
+ return nec7210_serial_poll_status(board, &priv->nec7210_priv);
+}
+
+static void fluke_return_to_local(gpib_board_t *board)
+{
+ struct fluke_priv *priv = board->private_data;
+ struct nec7210_priv *nec_priv = &priv->nec7210_priv;
+
+ write_byte(nec_priv, AUX_RTL2, AUXMR);
+ udelay(1);
+ write_byte(nec_priv, AUX_RTL, AUXMR);
+}
+
+static int fluke_line_status(const gpib_board_t *board)
+{
+ int status = ValidALL;
+ int bsr_bits;
+ struct fluke_priv *e_priv;
+ struct nec7210_priv *nec_priv;
+
+ e_priv = board->private_data;
+ nec_priv = &e_priv->nec7210_priv;
+
+ bsr_bits = fluke_paged_read_byte(e_priv, BUS_STATUS, BUS_STATUS_PAGE);
+
+ if ((bsr_bits & BSR_REN_BIT) == 0)
+ status |= BusREN;
+ if ((bsr_bits & BSR_IFC_BIT) == 0)
+ status |= BusIFC;
+ if ((bsr_bits & BSR_SRQ_BIT) == 0)
+ status |= BusSRQ;
+ if ((bsr_bits & BSR_EOI_BIT) == 0)
+ status |= BusEOI;
+ if ((bsr_bits & BSR_NRFD_BIT) == 0)
+ status |= BusNRFD;
+ if ((bsr_bits & BSR_NDAC_BIT) == 0)
+ status |= BusNDAC;
+ if ((bsr_bits & BSR_DAV_BIT) == 0)
+ status |= BusDAV;
+ if ((bsr_bits & BSR_ATN_BIT) == 0)
+ status |= BusATN;
+
+ return status;
+}
+
+static unsigned int fluke_t1_delay(gpib_board_t *board, unsigned int nano_sec)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ unsigned int retval;
+
+ retval = nec7210_t1_delay(board, nec_priv, nano_sec);
+
+ if (nano_sec <= 350) {
+ write_byte(nec_priv, AUX_HI_SPEED, AUXMR);
+ retval = 350;
+ } else {
+ write_byte(nec_priv, AUX_LO_SPEED, AUXMR);
+ }
+ return retval;
+}
+
+static int lacs_or_read_ready(gpib_board_t *board)
+{
+ const struct fluke_priv *e_priv = board->private_data;
+ const struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&board->spinlock, flags);
+ retval = test_bit(LACS_NUM, &board->status) || test_bit(READ_READY_BN, &nec_priv->state);
+ spin_unlock_irqrestore(&board->spinlock, flags);
+ return retval;
+}
+
+/* Wait until it is possible for a read to do something useful. This
+ * is not essential, it only exists to prevent RFD holdoff from being released pointlessly.
+ */
+static int wait_for_read(gpib_board_t *board)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ int retval = 0;
+
+ if (wait_event_interruptible(board->wait,
+ lacs_or_read_ready(board) ||
+ test_bit(DEV_CLEAR_BN, &nec_priv->state) ||
+ test_bit(TIMO_NUM, &board->status))) {
+ retval = -ERESTARTSYS;
+ }
+ if (test_bit(TIMO_NUM, &board->status))
+ retval = -ETIMEDOUT;
+ if (test_and_clear_bit(DEV_CLEAR_BN, &nec_priv->state))
+ retval = -EINTR;
+ return retval;
+}
+
+/* Check if the SH state machine is in SGNS. We check twice since there is a very small chance
+ * we could be blowing through SGNS from SIDS to SDYS if there is already a
+ * byte available in the handshake state machine. We are interested
+ * in the case where the handshake is stuck in SGNS due to no byte being
+ * available to the chip (and thus we can be confident a dma transfer will
+ * result in at least one byte making it into the chip). This matters
+ * because we want to be confident before sending a "send eoi" auxilary
+ * command that we will be able to also put the associated data byte
+ * in the chip before any potential timeout.
+ */
+static int source_handshake_is_sgns(struct fluke_priv *e_priv)
+{
+ int i;
+
+ for (i = 0; i < 2; ++i) {
+ if ((fluke_paged_read_byte(e_priv, STATE1_REG, STATE1_PAGE) &
+ SOURCE_HANDSHAKE_MASK) != SOURCE_HANDSHAKE_SGNS_BITS) {
+ return 0;
+ }
+ }
+ return 1;
+}
+
+static int source_handshake_is_sids_or_sgns(struct fluke_priv *e_priv)
+{
+ unsigned int source_handshake_bits;
+
+ source_handshake_bits = fluke_paged_read_byte(e_priv, STATE1_REG, STATE1_PAGE) &
+ SOURCE_HANDSHAKE_MASK;
+
+ return (source_handshake_bits == SOURCE_HANDSHAKE_SGNS_BITS) ||
+ (source_handshake_bits == SOURCE_HANDSHAKE_SIDS_BITS);
+}
+
+/* Wait until the gpib chip is ready to accept a data out byte.
+ * If the chip is SGNS it is probably waiting for a a byte to
+ * be written to it.
+ */
+static int wait_for_data_out_ready(gpib_board_t *board)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ int retval = 0;
+// printk("%s: enter\n", __FUNCTION__);
+
+ if (wait_event_interruptible(board->wait,
+ (test_bit(TACS_NUM, &board->status) &&
+ source_handshake_is_sgns(e_priv)) ||
+ test_bit(DEV_CLEAR_BN, &nec_priv->state) ||
+ test_bit(TIMO_NUM, &board->status))) {
+ retval = -ERESTARTSYS;
+ }
+ if (test_bit(TIMO_NUM, &board->status))
+ retval = -ETIMEDOUT;
+ if (test_and_clear_bit(DEV_CLEAR_BN, &nec_priv->state))
+ retval = -EINTR;
+// printk("%s: exit, retval=%i\n", __FUNCTION__, retval);
+ return retval;
+}
+
+static int wait_for_sids_or_sgns(gpib_board_t *board)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ int retval = 0;
+// printk("%s: enter\n", __FUNCTION__);
+
+ if (wait_event_interruptible(board->wait,
+ source_handshake_is_sids_or_sgns(e_priv) ||
+ test_bit(DEV_CLEAR_BN, &nec_priv->state) ||
+ test_bit(TIMO_NUM, &board->status)))
+ retval = -ERESTARTSYS;
+
+ if (test_bit(TIMO_NUM, &board->status))
+ retval = -ETIMEDOUT;
+ if (test_and_clear_bit(DEV_CLEAR_BN, &nec_priv->state))
+ retval = -EINTR;
+// printk("%s: exit, retval=%i\n", __FUNCTION__, retval);
+ return retval;
+}
+
+static void fluke_dma_callback(void *arg)
+{
+ gpib_board_t *board = arg;
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ unsigned long flags;
+
+ spin_lock_irqsave(&board->spinlock, flags);
+// printk("%s: enter\n", __FUNCTION__);
+
+ nec7210_set_reg_bits(nec_priv, IMR1, HR_DOIE | HR_DIIE, HR_DOIE | HR_DIIE);
+ wake_up_interruptible(&board->wait);
+
+ fluke_gpib_internal_interrupt(board);
+ clear_bit(DMA_WRITE_IN_PROGRESS_BN, &nec_priv->state);
+ clear_bit(DMA_READ_IN_PROGRESS_BN, &nec_priv->state);
+// printk("%s: exit\n", __FUNCTION__);
+ spin_unlock_irqrestore(&board->spinlock, flags);
+}
+
+static int fluke_dma_write(gpib_board_t *board, uint8_t *buffer, size_t length,
+ size_t *bytes_written)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ unsigned long flags;
+ int retval = 0;
+ dma_addr_t address;
+ struct dma_async_tx_descriptor *tx_desc;
+
+ *bytes_written = 0;
+// printk("%s: enter\n", __FUNCTION__);
+ if (WARN_ON_ONCE(length > e_priv->dma_buffer_size))
+ return -EFAULT;
+ dmaengine_terminate_all(e_priv->dma_channel);
+ // write-clear counter
+ writel(0x0, e_priv->write_transfer_counter);
+
+ memcpy(e_priv->dma_buffer, buffer, length);
+ address = dma_map_single(board->dev, e_priv->dma_buffer,
+ length, DMA_TO_DEVICE);
+ /* program dma controller */
+ retval = fluke_config_dma(board, 1);
+ if (retval)
+ goto cleanup;
+
+ tx_desc = dmaengine_prep_slave_single(e_priv->dma_channel, address, length, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!tx_desc) {
+ pr_err("fluke_gpib: failed to allocate dma transmit descriptor\n");
+ retval = -ENOMEM;
+ goto cleanup;
+ }
+ tx_desc->callback = fluke_dma_callback;
+ tx_desc->callback_param = board;
+
+ spin_lock_irqsave(&board->spinlock, flags);
+ nec7210_set_reg_bits(nec_priv, IMR1, HR_DOIE, 0);
+ nec7210_set_reg_bits(nec_priv, IMR2, HR_DMAO, HR_DMAO);
+ dmaengine_submit(tx_desc);
+ dma_async_issue_pending(e_priv->dma_channel);
+
+ clear_bit(WRITE_READY_BN, &nec_priv->state);
+ set_bit(DMA_WRITE_IN_PROGRESS_BN, &nec_priv->state);
+
+ // printk("%s: in spin lock\n", __FUNCTION__);
+ spin_unlock_irqrestore(&board->spinlock, flags);
+
+// printk("%s: waiting for write.\n", __FUNCTION__);
+ // suspend until message is sent
+ if (wait_event_interruptible(board->wait,
+ ((readl(e_priv->write_transfer_counter) &
+ write_transfer_counter_mask) == length) ||
+ test_bit(BUS_ERROR_BN, &nec_priv->state) ||
+ test_bit(DEV_CLEAR_BN, &nec_priv->state) ||
+ test_bit(TIMO_NUM, &board->status))) {
+ GPIB_DPRINTK("gpib write interrupted!\n");
+ retval = -ERESTARTSYS;
+ }
+ if (test_bit(TIMO_NUM, &board->status))
+ retval = -ETIMEDOUT;
+ if (test_and_clear_bit(DEV_CLEAR_BN, &nec_priv->state))
+ retval = -EINTR;
+ if (test_and_clear_bit(BUS_ERROR_BN, &nec_priv->state))
+ retval = -EIO;
+ // disable board's dma
+ nec7210_set_reg_bits(nec_priv, IMR2, HR_DMAO, 0);
+
+ dmaengine_terminate_all(e_priv->dma_channel);
+ // make sure fluke_dma_callback got called
+ if (test_bit(DMA_WRITE_IN_PROGRESS_BN, &nec_priv->state))
+ fluke_dma_callback(board);
+
+ /* if everything went fine, try to wait until last byte is actually
+ * transmitted across gpib (but don't try _too_ hard)
+ */
+ if (retval == 0)
+ retval = wait_for_sids_or_sgns(board);
+
+ *bytes_written = readl(e_priv->write_transfer_counter) & write_transfer_counter_mask;
+ if (WARN_ON_ONCE(*bytes_written > length))
+ return -EFAULT;
+
+cleanup:
+ dma_unmap_single(board->dev, address, length, DMA_TO_DEVICE);
+// printk("%s: exit, retval=%d\n", __FUNCTION__, retval);
+ return retval;
+}
+
+static int fluke_accel_write(gpib_board_t *board, uint8_t *buffer, size_t length,
+ int send_eoi, size_t *bytes_written)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ size_t remainder = length;
+ size_t transfer_size;
+ ssize_t retval = 0;
+ size_t dma_remainder = remainder;
+
+ if (!e_priv->dma_channel) {
+ pr_err("fluke_gpib: No dma channel available, cannot do accel write.");
+ return -ENXIO;
+ }
+
+ *bytes_written = 0;
+ if (length < 1)
+ return 0;
+
+ clear_bit(DEV_CLEAR_BN, &nec_priv->state); // XXX FIXME
+
+ if (send_eoi)
+ --dma_remainder;
+// printk("%s: entering while loop\n", __FUNCTION__);
+
+ while (dma_remainder > 0) {
+ size_t num_bytes;
+
+ retval = wait_for_data_out_ready(board);
+ if (retval < 0)
+ break;
+
+ transfer_size = (e_priv->dma_buffer_size < dma_remainder) ?
+ e_priv->dma_buffer_size : dma_remainder;
+ retval = fluke_dma_write(board, buffer, transfer_size, &num_bytes);
+ *bytes_written += num_bytes;
+ if (retval < 0)
+ break;
+ dma_remainder -= num_bytes;
+ remainder -= num_bytes;
+ buffer += num_bytes;
+ if (need_resched())
+ schedule();
+ }
+ if (retval < 0)
+ return retval;
+ //handle sending of last byte with eoi
+ if (send_eoi) {
+ size_t num_bytes;
+ // printk("%s: handling last byte\n", __FUNCTION__);
+ if (WARN_ON_ONCE(remainder != 1))
+ return -EFAULT;
+
+ /* wait until we are sure we will be able to write the data byte
+ * into the chip before we send AUX_SEOI. This prevents a timeout
+ * scenerio where we send AUX_SEOI but then timeout without getting
+ * any bytes into the gpib chip. This will result in the first byte
+ * of the next write having a spurious EOI set on the first byte.
+ */
+ retval = wait_for_data_out_ready(board);
+ if (retval < 0)
+ return retval;
+
+ write_byte(nec_priv, AUX_SEOI, AUXMR);
+ retval = fluke_dma_write(board, buffer, remainder, &num_bytes);
+ *bytes_written += num_bytes;
+ if (retval < 0)
+ return retval;
+ remainder -= num_bytes;
+ }
+// printk("%s: bytes send=%i\n", __FUNCTION__, (int)(length - remainder));
+ return 0;
+}
+
+static unsigned int fluke_get_dma_residue(struct dma_chan *chan, dma_cookie_t cookie)
+{
+ struct dma_tx_state state;
+ int result;
+
+ result = dmaengine_pause(chan);
+ if (result < 0) {
+ pr_err("fluke_gpib: dma pause failed?\n");
+ return -1;
+ }
+ dmaengine_tx_status(chan, cookie, &state);
+ // hardware doesn't support resume, so dont call this
+ // method unless the dma transfer is done.
+ return state.residue;
+}
+
+static int fluke_dma_read(gpib_board_t *board, uint8_t *buffer,
+ size_t length, int *end, size_t *bytes_read)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ int retval = 0;
+ unsigned long flags;
+ unsigned int residue;
+ dma_addr_t bus_address;
+ struct dma_async_tx_descriptor *tx_desc;
+ dma_cookie_t dma_cookie;
+ int i;
+ static const int timeout = 10;
+
+ // printk("%s: enter, bus_address=0x%x, length=%i\n", __FUNCTION__,
+ // (unsigned)bus_address,
+ // (int)length);
+
+ *bytes_read = 0;
+ *end = 0;
+ if (length == 0)
+ return 0;
+
+ bus_address = dma_map_single(board->dev, e_priv->dma_buffer,
+ length, DMA_FROM_DEVICE);
+
+ /* program dma controller */
+ retval = fluke_config_dma(board, 0);
+ if (retval) {
+ dma_unmap_single(board->dev, bus_address, length, DMA_FROM_DEVICE);
+ return retval;
+ }
+ tx_desc = dmaengine_prep_slave_single(e_priv->dma_channel,
+ bus_address, length, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!tx_desc) {
+ pr_err("fluke_gpib: failed to allocate dma transmit descriptor\n");
+ dma_unmap_single(NULL, bus_address, length, DMA_FROM_DEVICE);
+ return -EIO;
+ }
+ tx_desc->callback = fluke_dma_callback;
+ tx_desc->callback_param = board;
+
+ spin_lock_irqsave(&board->spinlock, flags);
+ // enable nec7210 dma
+ nec7210_set_reg_bits(nec_priv, IMR1, HR_DIIE, 0);
+ nec7210_set_reg_bits(nec_priv, IMR2, HR_DMAI, HR_DMAI);
+
+ dma_cookie = dmaengine_submit(tx_desc);
+ dma_async_issue_pending(e_priv->dma_channel);
+
+ set_bit(DMA_READ_IN_PROGRESS_BN, &nec_priv->state);
+ clear_bit(READ_READY_BN, &nec_priv->state);
+
+ spin_unlock_irqrestore(&board->spinlock, flags);
+// printk("waiting for data transfer.\n");
+ // wait for data to transfer
+ if (wait_event_interruptible(board->wait,
+ test_bit(DMA_READ_IN_PROGRESS_BN, &nec_priv->state) == 0 ||
+ test_bit(RECEIVED_END_BN, &nec_priv->state) ||
+ test_bit(DEV_CLEAR_BN, &nec_priv->state) ||
+ test_bit(TIMO_NUM, &board->status))) {
+ pr_warn("fluke: dma read wait interrupted\n");
+ retval = -ERESTARTSYS;
+ }
+ if (test_bit(TIMO_NUM, &board->status))
+ retval = -ETIMEDOUT;
+ if (test_bit(DEV_CLEAR_BN, &nec_priv->state))
+ retval = -EINTR;
+
+ /* If we woke up because of end, wait until the dma transfer has pulled
+ * the data byte associated with the end before we cancel the dma transfer.
+ */
+ if (test_bit(RECEIVED_END_BN, &nec_priv->state)) {
+ for (i = 0; i < timeout; ++i) {
+ if (test_bit(DMA_READ_IN_PROGRESS_BN, &nec_priv->state) == 0)
+ break;
+ if ((read_byte(nec_priv, ADR0) & DATA_IN_STATUS) == 0)
+ break;
+ usleep_range(10, 15);
+ }
+ if (i == timeout)
+ pr_warn("fluke_gpib: timeout waiting for dma to transfer end data byte.\n");
+ }
+
+ // stop the dma transfer
+ nec7210_set_reg_bits(nec_priv, IMR2, HR_DMAI, 0);
+ /* delay a little just to make sure any bytes in dma controller's fifo get
+ * written to memory before we disable it
+ */
+ usleep_range(10, 15);
+ residue = fluke_get_dma_residue(e_priv->dma_channel, dma_cookie);
+ if (WARN_ON_ONCE(residue > length || residue < 0))
+ return -EFAULT;
+ *bytes_read += length - residue;
+ dmaengine_terminate_all(e_priv->dma_channel);
+ // make sure fluke_dma_callback got called
+ if (test_bit(DMA_READ_IN_PROGRESS_BN, &nec_priv->state))
+ fluke_dma_callback(board);
+
+ dma_unmap_single(board->dev, bus_address, length, DMA_FROM_DEVICE);
+ memcpy(buffer, e_priv->dma_buffer, *bytes_read);
+
+ /* If we got an end interrupt, figure out if it was
+ * associated with the last byte we dma'd or with a
+ * byte still sitting on the cb7210.
+ */
+ spin_lock_irqsave(&board->spinlock, flags);
+ if (test_bit(READ_READY_BN, &nec_priv->state) == 0) {
+ // There is no byte sitting on the cb7210. If we
+ // saw an end interrupt, we need to deal with it now
+ if (test_and_clear_bit(RECEIVED_END_BN, &nec_priv->state))
+ *end = 1;
+ }
+ spin_unlock_irqrestore(&board->spinlock, flags);
+
+ return retval;
+}
+
+static int fluke_accel_read(gpib_board_t *board, uint8_t *buffer, size_t length,
+ int *end, size_t *bytes_read)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+ size_t remain = length;
+ size_t transfer_size;
+ int retval = 0;
+ size_t dma_nbytes;
+
+/* printk("%s: enter, buffer=0x%p, length=%i\n", __FUNCTION__,
+ * buffer, (int)length);
+ * printk("\t dma_buffer=0x%p\n", e_priv->dma_buffer);
+ */
+ *end = 0;
+ *bytes_read = 0;
+
+ smp_mb__before_atomic();
+ clear_bit(DEV_CLEAR_BN, &nec_priv->state); // XXX FIXME
+ smp_mb__after_atomic();
+
+ retval = wait_for_read(board);
+ if (retval < 0)
+ return retval;
+
+ nec7210_release_rfd_holdoff(board, nec_priv);
+
+// printk("%s: entering while loop\n", __FUNCTION__);
+ while (remain > 0) {
+ transfer_size = (e_priv->dma_buffer_size < remain) ?
+ e_priv->dma_buffer_size : remain;
+ retval = fluke_dma_read(board, buffer, transfer_size, end, &dma_nbytes);
+ remain -= dma_nbytes;
+ buffer += dma_nbytes;
+ *bytes_read += dma_nbytes;
+ if (*end)
+ break;
+ if (retval < 0) {
+// printk("%s: early exit, retval=%i\n", __FUNCTION__, (int)retval);
+ return retval;
+ }
+ if (need_resched())
+ schedule();
+ }
+// printk("%s: exit, retval=%i\n", __FUNCTION__, (int)retval);
+ return retval;
+}
+
+gpib_interface_t fluke_unaccel_interface = {
+name: "fluke_unaccel",
+attach : fluke_attach_holdoff_all,
+detach : fluke_detach,
+read : fluke_read,
+write : fluke_write,
+command : fluke_command,
+take_control : fluke_take_control,
+go_to_standby : fluke_go_to_standby,
+request_system_control : fluke_request_system_control,
+interface_clear : fluke_interface_clear,
+remote_enable : fluke_remote_enable,
+enable_eos : fluke_enable_eos,
+disable_eos : fluke_disable_eos,
+parallel_poll : fluke_parallel_poll,
+parallel_poll_configure : fluke_parallel_poll_configure,
+parallel_poll_response : fluke_parallel_poll_response,
+line_status : fluke_line_status,
+update_status : fluke_update_status,
+primary_address : fluke_primary_address,
+secondary_address : fluke_secondary_address,
+serial_poll_response : fluke_serial_poll_response,
+serial_poll_status : fluke_serial_poll_status,
+t1_delay : fluke_t1_delay,
+return_to_local : fluke_return_to_local,
+};
+
+/* fluke_hybrid uses dma for writes but not for reads. Added
+ * to deal with occasional corruption of bytes seen when doing dma
+ * reads. From looking at the cb7210 vhdl, I believe the corruption
+ * is due to a hardware bug triggered by the cpu reading a cb7210
+ * }
+ * register just as the dma controller is also doing a read.
+ */
+
+gpib_interface_t fluke_hybrid_interface = {
+name: "fluke_hybrid",
+attach : fluke_attach_holdoff_all,
+detach : fluke_detach,
+read : fluke_read,
+write : fluke_accel_write,
+command : fluke_command,
+take_control : fluke_take_control,
+go_to_standby : fluke_go_to_standby,
+request_system_control : fluke_request_system_control,
+interface_clear : fluke_interface_clear,
+remote_enable : fluke_remote_enable,
+enable_eos : fluke_enable_eos,
+disable_eos : fluke_disable_eos,
+parallel_poll : fluke_parallel_poll,
+parallel_poll_configure : fluke_parallel_poll_configure,
+parallel_poll_response : fluke_parallel_poll_response,
+line_status : fluke_line_status,
+update_status : fluke_update_status,
+primary_address : fluke_primary_address,
+secondary_address : fluke_secondary_address,
+serial_poll_response : fluke_serial_poll_response,
+serial_poll_status : fluke_serial_poll_status,
+t1_delay : fluke_t1_delay,
+return_to_local : fluke_return_to_local,
+};
+
+gpib_interface_t fluke_interface = {
+name: "fluke",
+attach : fluke_attach_holdoff_end,
+detach : fluke_detach,
+read : fluke_accel_read,
+write : fluke_accel_write,
+command : fluke_command,
+take_control : fluke_take_control,
+go_to_standby : fluke_go_to_standby,
+request_system_control : fluke_request_system_control,
+interface_clear : fluke_interface_clear,
+remote_enable : fluke_remote_enable,
+enable_eos : fluke_enable_eos,
+disable_eos : fluke_disable_eos,
+parallel_poll : fluke_parallel_poll,
+parallel_poll_configure : fluke_parallel_poll_configure,
+parallel_poll_response : fluke_parallel_poll_response,
+line_status : fluke_line_status,
+update_status : fluke_update_status,
+primary_address : fluke_primary_address,
+secondary_address : fluke_secondary_address,
+serial_poll_response : fluke_serial_poll_response,
+serial_poll_status : fluke_serial_poll_status,
+t1_delay : fluke_t1_delay,
+return_to_local : fluke_return_to_local,
+};
+
+irqreturn_t fluke_gpib_internal_interrupt(gpib_board_t *board)
+{
+ int status0, status1, status2;
+ struct fluke_priv *priv = board->private_data;
+ struct nec7210_priv *nec_priv = &priv->nec7210_priv;
+ int retval = IRQ_NONE;
+
+ if (read_byte(nec_priv, ADR0) & DATA_IN_STATUS)
+ set_bit(READ_READY_BN, &nec_priv->state);
+
+ status0 = fluke_paged_read_byte(priv, ISR0_IMR0, ISR0_IMR0_PAGE);
+ status1 = read_byte(nec_priv, ISR1);
+ status2 = read_byte(nec_priv, ISR2);
+
+ if (status0 & FLUKE_IFCI_BIT) {
+ push_gpib_event(board, EventIFC);
+ retval = IRQ_HANDLED;
+ }
+
+ if (nec7210_interrupt_have_status(board, nec_priv, status1, status2) == IRQ_HANDLED)
+ retval = IRQ_HANDLED;
+/*
+ * if((status1 & nec_priv->reg_bits[IMR1]) ||
+ * (status2 & (nec_priv->reg_bits[IMR2] & IMR2_ENABLE_INTR_MASK)))
+ * {
+ * printk("fluke: status1 0x%x, status2 0x%x\n", status1, status2);
+ * }
+ */
+
+ if (read_byte(nec_priv, ADR0) & DATA_IN_STATUS) {
+ if (test_bit(RFD_HOLDOFF_BN, &nec_priv->state))
+ set_bit(READ_READY_BN, &nec_priv->state);
+ else
+ clear_bit(READ_READY_BN, &nec_priv->state);
+ }
+
+ if (retval == IRQ_HANDLED)
+ wake_up_interruptible(&board->wait);
+
+ return retval;
+}
+
+static irqreturn_t fluke_gpib_interrupt(int irq, void *arg)
+{
+ gpib_board_t *board = arg;
+ unsigned long flags;
+ irqreturn_t retval;
+
+ spin_lock_irqsave(&board->spinlock, flags);
+ retval = fluke_gpib_internal_interrupt(board);
+ spin_unlock_irqrestore(&board->spinlock, flags);
+ return retval;
+}
+
+static int fluke_allocate_private(gpib_board_t *board)
+{
+ struct fluke_priv *priv;
+
+ board->private_data = kmalloc(sizeof(struct fluke_priv), GFP_KERNEL);
+ if (!board->private_data)
+ return -ENOMEM;
+ priv = board->private_data;
+ memset(priv, 0, sizeof(struct fluke_priv));
+ init_nec7210_private(&priv->nec7210_priv);
+ priv->dma_buffer_size = 0x7ff;
+ priv->dma_buffer = kmalloc(priv->dma_buffer_size, GFP_KERNEL);
+ if (!priv->dma_buffer)
+ return -ENOMEM;
+ return 0;
+}
+
+static void fluke_generic_detach(gpib_board_t *board)
+{
+ if (board->private_data) {
+ struct fluke_priv *e_priv = board->private_data;
+
+ kfree(e_priv->dma_buffer);
+ kfree(board->private_data);
+ board->private_data = NULL;
+ }
+}
+
+// generic part of attach functions shared by all cb7210 boards
+static int fluke_generic_attach(gpib_board_t *board)
+{
+ struct fluke_priv *e_priv;
+ struct nec7210_priv *nec_priv;
+ int retval;
+
+ board->status = 0;
+
+ retval = fluke_allocate_private(board);
+ if (retval < 0)
+ return retval;
+ e_priv = board->private_data;
+ nec_priv = &e_priv->nec7210_priv;
+ nec_priv->read_byte = fluke_locking_read_byte;
+ nec_priv->write_byte = fluke_locking_write_byte;
+ nec_priv->offset = fluke_reg_offset;
+ nec_priv->type = CB7210;
+ return 0;
+}
+
+static int fluke_config_dma(gpib_board_t *board, int output)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct dma_slave_config config;
+
+ config.src_maxburst = 1;
+ config.dst_maxburst = 1;
+ config.device_fc = true;
+
+ if (output) {
+ config.direction = DMA_MEM_TO_DEV;
+ config.src_addr = 0;
+ config.dst_addr = e_priv->dma_port_res->start;
+ config.src_addr_width = 1;
+ config.dst_addr_width = 1;
+ } else {
+ config.direction = DMA_DEV_TO_MEM;
+ config.src_addr = e_priv->dma_port_res->start;
+ config.dst_addr = 0;
+ config.src_addr_width = 1;
+ config.dst_addr_width = 1;
+ }
+ return dmaengine_slave_config(e_priv->dma_channel, &config);
+}
+
+static int fluke_init(struct fluke_priv *e_priv, gpib_board_t *board, int handshake_mode)
+{
+ struct nec7210_priv *nec_priv = &e_priv->nec7210_priv;
+
+ nec7210_board_reset(nec_priv, board);
+ write_byte(nec_priv, AUX_LO_SPEED, AUXMR);
+ /* set clock register for driving frequency
+ * ICR should be set to clock in megahertz (1-15) and to zero
+ * for clocks faster than 15 MHz (max 20MHz)
+ */
+ write_byte(nec_priv, ICR | 10, AUXMR);
+ nec7210_set_handshake_mode(board, nec_priv, handshake_mode);
+
+ nec7210_board_online(nec_priv, board);
+
+ /* poll so we can detect ATN changes */
+ if (gpib_request_pseudo_irq(board, fluke_gpib_interrupt)) {
+ pr_err("fluke_gpib: failed to allocate pseudo_irq\n");
+ return -EINVAL;
+ }
+
+ fluke_paged_write_byte(e_priv, FLUKE_IFCIE_BIT, ISR0_IMR0, ISR0_IMR0_PAGE);
+ return 0;
+}
+
+/* This function is passed to dma_request_channel() in order to
+ * select the pl330 dma channel which has been hardwired to
+ * the gpib controller.
+ */
+static bool gpib_dma_channel_filter(struct dma_chan *chan, void *filter_param)
+{
+ // select the channel which is wired to the gpib chip
+ return chan->chan_id == 0;
+}
+
+static int fluke_attach_impl(gpib_board_t *board, const gpib_board_config_t *config,
+ unsigned int handshake_mode)
+{
+ struct fluke_priv *e_priv;
+ struct nec7210_priv *nec_priv;
+ int isr_flags = 0;
+ int retval;
+ int irq;
+ struct resource *res;
+ dma_cap_mask_t dma_cap;
+
+ if (!fluke_gpib_pdev) {
+ pr_err("No gpib platform device was found, attach failed.\n");
+ return -ENODEV;
+ }
+
+ retval = fluke_generic_attach(board);
+ if (retval)
+ return retval;
+
+ e_priv = board->private_data;
+ nec_priv = &e_priv->nec7210_priv;
+ nec_priv->offset = fluke_reg_offset;
+ board->dev = &fluke_gpib_pdev->dev;
+
+ res = platform_get_resource(fluke_gpib_pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&fluke_gpib_pdev->dev, "Unable to locate mmio resource for cb7210 gpib\n");
+ return -ENODEV;
+ }
+
+ if (request_mem_region(res->start,
+ resource_size(res),
+ fluke_gpib_pdev->name) == NULL) {
+ dev_err(&fluke_gpib_pdev->dev, "cannot claim registers\n");
+ return -ENXIO;
+ }
+ e_priv->gpib_iomem_res = res;
+
+ nec_priv->iobase = ioremap(e_priv->gpib_iomem_res->start,
+ resource_size(e_priv->gpib_iomem_res));
+ pr_info("gpib: iobase %lx remapped to %p, length=%d\n",
+ (unsigned long)e_priv->gpib_iomem_res->start,
+ nec_priv->iobase, (int)resource_size(e_priv->gpib_iomem_res));
+ if (!nec_priv->iobase) {
+ dev_err(&fluke_gpib_pdev->dev, "Could not map I/O memory\n");
+ return -ENOMEM;
+ }
+
+ res = platform_get_resource(fluke_gpib_pdev, IORESOURCE_MEM, 1);
+ if (!res) {
+ dev_err(&fluke_gpib_pdev->dev, "Unable to locate mmio resource for gpib dma port\n");
+ return -ENODEV;
+ }
+ if (request_mem_region(res->start,
+ resource_size(res),
+ fluke_gpib_pdev->name) == NULL) {
+ dev_err(&fluke_gpib_pdev->dev, "cannot claim registers\n");
+ return -ENXIO;
+ }
+ e_priv->dma_port_res = res;
+
+ res = platform_get_resource(fluke_gpib_pdev, IORESOURCE_MEM, 2);
+ if (!res) {
+ dev_err(&fluke_gpib_pdev->dev, "Unable to locate mmio resource for write transfer counter\n");
+ return -ENODEV;
+ }
+
+ if (request_mem_region(res->start,
+ resource_size(res),
+ fluke_gpib_pdev->name) == NULL) {
+ dev_err(&fluke_gpib_pdev->dev, "cannot claim registers\n");
+ return -ENXIO;
+ }
+ e_priv->write_transfer_counter_res = res;
+
+ e_priv->write_transfer_counter = ioremap(e_priv->write_transfer_counter_res->start,
+ resource_size(e_priv->write_transfer_counter_res));
+ pr_info("gpib: write transfer counter %lx remapped to %p, length=%d\n",
+ (unsigned long)e_priv->write_transfer_counter_res->start,
+ e_priv->write_transfer_counter,
+ (int)resource_size(e_priv->write_transfer_counter_res));
+ if (!e_priv->write_transfer_counter) {
+ dev_err(&fluke_gpib_pdev->dev, "Could not map I/O memory\n");
+ return -ENOMEM;
+ }
+
+ irq = platform_get_irq(fluke_gpib_pdev, 0);
+ pr_info("gpib: irq %d\n", irq);
+ if (irq < 0) {
+ dev_err(&fluke_gpib_pdev->dev, "fluke_gpib: request for IRQ failed\n");
+ return -EBUSY;
+ }
+ retval = request_irq(irq, fluke_gpib_interrupt, isr_flags, fluke_gpib_pdev->name, board);
+ if (retval) {
+ dev_err(&fluke_gpib_pdev->dev,
+ "cannot register interrupt handler err=%d\n",
+ retval);
+ return retval;
+ }
+ e_priv->irq = irq;
+
+ dma_cap_zero(dma_cap);
+ dma_cap_set(DMA_SLAVE, dma_cap);
+ e_priv->dma_channel = dma_request_channel(dma_cap, gpib_dma_channel_filter, NULL);
+ if (!e_priv->dma_channel) {
+ pr_err("fluke_gpib: failed to allocate a dma channel.\n");
+ // we don't error out here because unaccel interface will still
+ // work without dma
+ }
+
+ return fluke_init(e_priv, board, handshake_mode);
+}
+
+int fluke_attach_holdoff_all(gpib_board_t *board, const gpib_board_config_t *config)
+{
+ return fluke_attach_impl(board, config, HR_HLDA);
+}
+
+int fluke_attach_holdoff_end(gpib_board_t *board, const gpib_board_config_t *config)
+{
+ return fluke_attach_impl(board, config, HR_HLDE);
+}
+
+void fluke_detach(gpib_board_t *board)
+{
+ struct fluke_priv *e_priv = board->private_data;
+ struct nec7210_priv *nec_priv;
+
+ if (e_priv) {
+ if (e_priv->dma_channel)
+ dma_release_channel(e_priv->dma_channel);
+ gpib_free_pseudo_irq(board);
+ nec_priv = &e_priv->nec7210_priv;
+
+ if (nec_priv->iobase) {
+ fluke_paged_write_byte(e_priv, 0, ISR0_IMR0, ISR0_IMR0_PAGE);
+ nec7210_board_reset(nec_priv, board);
+ }
+ if (e_priv->irq)
+ free_irq(e_priv->irq, board);
+ if (e_priv->write_transfer_counter_res) {
+ release_mem_region(e_priv->write_transfer_counter_res->start,
+ resource_size(e_priv->write_transfer_counter_res));
+ }
+ if (e_priv->dma_port_res) {
+ release_mem_region(e_priv->dma_port_res->start,
+ resource_size(e_priv->dma_port_res));
+ }
+ if (e_priv->gpib_iomem_res)
+ release_mem_region(e_priv->gpib_iomem_res->start,
+ resource_size(e_priv->gpib_iomem_res));
+ }
+ fluke_generic_detach(board);
+}
+
+static int fluke_gpib_probe(struct platform_device *pdev)
+{
+ fluke_gpib_pdev = pdev;
+ return 0;
+}
+
+static const struct of_device_id fluke_gpib_of_match[] = {
+ { .compatible = "flk,fgpib-4.0"},
+ { {0} }
+};
+MODULE_DEVICE_TABLE(of, fluke_gpib_of_match);
+
+static struct platform_driver fluke_gpib_platform_driver = {
+ .driver = {
+ .name = "fluke_gpib",
+ .owner = THIS_MODULE,
+ .of_match_table = fluke_gpib_of_match,
+ },
+ .probe = &fluke_gpib_probe
+};
+
+static int __init fluke_init_module(void)
+{
+ int result;
+
+ result = platform_driver_register(&fluke_gpib_platform_driver);
+ if (result) {
+ pr_err("fluke_gpib: platform_driver_register failed!\n");
+ return result;
+ }
+
+ gpib_register_driver(&fluke_unaccel_interface, THIS_MODULE);
+ gpib_register_driver(&fluke_hybrid_interface, THIS_MODULE);
+ gpib_register_driver(&fluke_interface, THIS_MODULE);
+
+ pr_info("fluke_gpib\n");
+ return 0;
+}
+
+static void __exit fluke_exit_module(void)
+{
+ gpib_unregister_driver(&fluke_unaccel_interface);
+ gpib_unregister_driver(&fluke_hybrid_interface);
+ gpib_unregister_driver(&fluke_interface);
+ platform_driver_unregister(&fluke_gpib_platform_driver);
+}
+
+module_init(fluke_init_module);
+module_exit(fluke_exit_module);
projects / linux-block.git / commitdiff