staging: gpib: Add Computer Equipment Corporation GPIB driver

Driver for Computer Equipment Corporation and compatible boards.

Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20240918121908.19366-12-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gpib/cec/Makefile

@@ -0,0 +1,3 @@
+
+obj-m += cec_gpib.o
+

drivers/staging/gpib/cec/cec.h

@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/***************************************************************************
+ *    copyright            : (C) 2002 by Frank Mori Hess
+ ***************************************************************************/
+
+#include "nec7210.h"
+#include "gpibP.h"
+#include "plx9050.h"
+
+struct cec_priv  {
+	struct nec7210_priv nec7210_priv;
+	struct pci_dev *pci_device;
+	// base address for plx9052 pci chip
+	unsigned long plx_iobase;
+	unsigned int irq;
+};
+
+// interfaces
+extern gpib_interface_t cec_pci_interface;
+extern gpib_interface_t cec_pcmcia_interface;
+
+// interface functions
+int cec_read(gpib_board_t *board, uint8_t *buffer, size_t length, int *end, size_t *bytes_read);
+int cec_write(gpib_board_t *board, uint8_t *buffer, size_t length, int send_eoi,
+	      size_t *bytes_written);
+int cec_command(gpib_board_t *board, uint8_t *buffer, size_t length, size_t *bytes_written);
+int cec_take_control(gpib_board_t *board, int synchronous);
+int cec_go_to_standby(gpib_board_t *board);
+void cec_request_system_control(gpib_board_t *board, int request_control);
+void cec_interface_clear(gpib_board_t *board, int assert);
+void cec_remote_enable(gpib_board_t *board, int enable);
+int cec_enable_eos(gpib_board_t *board, uint8_t eos_byte, int compare_8_bits);
+void cec_disable_eos(gpib_board_t *board);
+unsigned int cec_update_status(gpib_board_t *board, unsigned int clear_mask);
+int cec_primary_address(gpib_board_t *board, unsigned int address);
+int cec_secondary_address(gpib_board_t *board, unsigned int address, int enable);
+int cec_parallel_poll(gpib_board_t *board, uint8_t *result);
+void cec_parallel_poll_configure(gpib_board_t *board, uint8_t configuration);
+void cec_parallel_poll_response(gpib_board_t *board, int ist);
+void cec_serial_poll_response(gpib_board_t *board, uint8_t status);
+void cec_return_to_local(gpib_board_t *board);
+
+// interrupt service routines
+irqreturn_t cec_interrupt(int irq, void *arg);
+
+// utility functions
+void cec_free_private(gpib_board_t *board);
+int cec_generic_attach(gpib_board_t *board);
+void cec_init(struct cec_priv *priv, const gpib_board_t *board);
+
+// offset between consecutive nec7210 registers
+static const int cec_reg_offset = 1;

drivers/staging/gpib/cec/cec_gpib.c

@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/***************************************************************************
+ *   copyright            : (C) 2002 by Frank Mori Hess
+ ***************************************************************************/
+
+#include "cec.h"
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/bitops.h>
+#include <asm/dma.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+MODULE_LICENSE("GPL");
+
+/*
+ * GPIB interrupt service routines
+ */
+
+irqreturn_t cec_interrupt(int irq, void *arg)
+{
+	gpib_board_t *board = arg;
+	struct cec_priv *priv = board->private_data;
+	unsigned long flags;
+	irqreturn_t retval;
+
+	spin_lock_irqsave(&board->spinlock, flags);
+	retval = nec7210_interrupt(board, &priv->nec7210_priv);
+	spin_unlock_irqrestore(&board->spinlock, flags);
+	return retval;
+}
+
+#define CEC_VENDOR_ID 0x12fc
+#define CEC_DEV_ID    0x5cec
+#define CEC_SUBID 0x9050
+
+static int cec_pci_attach(gpib_board_t *board, const gpib_board_config_t *config);
+
+static void cec_pci_detach(gpib_board_t *board);
+
+// wrappers for interface functions
+int cec_read(gpib_board_t *board, uint8_t *buffer, size_t length, int *end, size_t *bytes_read)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_read(board, &priv->nec7210_priv, buffer, length, end, bytes_read);
+}
+
+int cec_write(gpib_board_t *board, uint8_t *buffer, size_t length, int send_eoi,
+	      size_t *bytes_written)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_write(board, &priv->nec7210_priv, buffer, length, send_eoi, bytes_written);
+}
+
+int cec_command(gpib_board_t *board, uint8_t *buffer, size_t length, size_t *bytes_written)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_command(board, &priv->nec7210_priv, buffer, length, bytes_written);
+}
+
+int cec_take_control(gpib_board_t *board, int synchronous)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_take_control(board, &priv->nec7210_priv, synchronous);
+}
+
+int cec_go_to_standby(gpib_board_t *board)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_go_to_standby(board, &priv->nec7210_priv);
+}
+
+void cec_request_system_control(gpib_board_t *board, int request_control)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_request_system_control(board, &priv->nec7210_priv, request_control);
+}
+
+void cec_interface_clear(gpib_board_t *board, int assert)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_interface_clear(board, &priv->nec7210_priv, assert);
+}
+
+void cec_remote_enable(gpib_board_t *board, int enable)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_remote_enable(board, &priv->nec7210_priv, enable);
+}
+
+int cec_enable_eos(gpib_board_t *board, uint8_t eos_byte, int compare_8_bits)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_enable_eos(board, &priv->nec7210_priv, eos_byte, compare_8_bits);
+}
+
+void cec_disable_eos(gpib_board_t *board)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_disable_eos(board, &priv->nec7210_priv);
+}
+
+unsigned int cec_update_status(gpib_board_t *board, unsigned int clear_mask)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_update_status(board, &priv->nec7210_priv, clear_mask);
+}
+
+int cec_primary_address(gpib_board_t *board, unsigned int address)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_primary_address(board, &priv->nec7210_priv, address);
+}
+
+int cec_secondary_address(gpib_board_t *board, unsigned int address, int enable)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_secondary_address(board, &priv->nec7210_priv, address, enable);
+}
+
+int cec_parallel_poll(gpib_board_t *board, uint8_t *result)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_parallel_poll(board, &priv->nec7210_priv, result);
+}
+
+void cec_parallel_poll_configure(gpib_board_t *board, uint8_t config)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_parallel_poll_configure(board, &priv->nec7210_priv, config);
+}
+
+void cec_parallel_poll_response(gpib_board_t *board, int ist)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_parallel_poll_response(board, &priv->nec7210_priv, ist);
+}
+
+void cec_serial_poll_response(gpib_board_t *board, uint8_t status)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_serial_poll_response(board, &priv->nec7210_priv, status);
+}
+
+static uint8_t cec_serial_poll_status(gpib_board_t *board)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_serial_poll_status(board, &priv->nec7210_priv);
+}
+
+static unsigned int cec_t1_delay(gpib_board_t *board, unsigned int nano_sec)
+{
+	struct cec_priv *priv = board->private_data;
+
+	return nec7210_t1_delay(board, &priv->nec7210_priv, nano_sec);
+}
+
+void cec_return_to_local(gpib_board_t *board)
+{
+	struct cec_priv *priv = board->private_data;
+
+	nec7210_return_to_local(board, &priv->nec7210_priv);
+}
+
+gpib_interface_t cec_pci_interface = {
+name: "cec_pci",
+attach : cec_pci_attach,
+detach : cec_pci_detach,
+read : cec_read,
+write : cec_write,
+command : cec_command,
+take_control : cec_take_control,
+go_to_standby : cec_go_to_standby,
+request_system_control : cec_request_system_control,
+interface_clear : cec_interface_clear,
+remote_enable : cec_remote_enable,
+enable_eos : cec_enable_eos,
+disable_eos : cec_disable_eos,
+parallel_poll : cec_parallel_poll,
+parallel_poll_configure : cec_parallel_poll_configure,
+parallel_poll_response : cec_parallel_poll_response,
+local_parallel_poll_mode : NULL, // XXX
+line_status : NULL,	//XXX
+update_status : cec_update_status,
+primary_address : cec_primary_address,
+secondary_address : cec_secondary_address,
+serial_poll_response : cec_serial_poll_response,
+serial_poll_status : cec_serial_poll_status,
+t1_delay : cec_t1_delay,
+return_to_local : cec_return_to_local,
+};
+
+static int cec_allocate_private(gpib_board_t *board)
+{
+	struct cec_priv *priv;
+
+	board->private_data = kmalloc(sizeof(struct cec_priv), GFP_KERNEL);
+	if (!board->private_data)
+		return -1;
+	priv = board->private_data;
+	memset(priv, 0, sizeof(struct cec_priv));
+	init_nec7210_private(&priv->nec7210_priv);
+	return 0;
+}
+
+void cec_free_private(gpib_board_t *board)
+{
+	kfree(board->private_data);
+	board->private_data = NULL;
+}
+
+int cec_generic_attach(gpib_board_t *board)
+{
+	struct cec_priv *cec_priv;
+	struct nec7210_priv *nec_priv;
+
+	board->status = 0;
+
+	if (cec_allocate_private(board))
+		return -ENOMEM;
+	cec_priv = board->private_data;
+	nec_priv = &cec_priv->nec7210_priv;
+	nec_priv->read_byte = nec7210_ioport_read_byte;
+	nec_priv->write_byte = nec7210_ioport_write_byte;
+	nec_priv->offset = cec_reg_offset;
+	nec_priv->type = NEC7210;	// guess
+	return 0;
+}
+
+void cec_init(struct cec_priv *cec_priv, const gpib_board_t *board)
+{
+	struct nec7210_priv *nec_priv = &cec_priv->nec7210_priv;
+
+	nec7210_board_reset(nec_priv, board);
+
+	/* set internal counter register for 8 MHz input clock */
+	write_byte(nec_priv, ICR | 8, AUXMR);
+
+	nec7210_board_online(nec_priv, board);
+}
+
+int cec_pci_attach(gpib_board_t *board, const gpib_board_config_t *config)
+{
+	struct cec_priv *cec_priv;
+	struct nec7210_priv *nec_priv;
+	int isr_flags = 0;
+	int retval;
+
+	retval = cec_generic_attach(board);
+	if (retval)
+		return retval;
+
+	cec_priv = board->private_data;
+	nec_priv = &cec_priv->nec7210_priv;
+
+	// find board
+	cec_priv->pci_device = NULL;
+	while ((cec_priv->pci_device =
+		gpib_pci_get_device(config, CEC_VENDOR_ID,
+				    CEC_DEV_ID, cec_priv->pci_device)))	{
+		// check for board with plx9050 controller
+		if (cec_priv->pci_device->subsystem_device == CEC_SUBID)
+			break;
+	}
+	if (!cec_priv->pci_device) {
+		pr_err("gpib: no cec PCI board found\n");
+		return -1;
+	}
+
+	if (pci_enable_device(cec_priv->pci_device)) {
+		pr_err("error enabling pci device\n");
+		return -1;
+	}
+
+	if (pci_request_regions(cec_priv->pci_device, "cec-gpib"))
+		return -1;
+
+	cec_priv->plx_iobase = pci_resource_start(cec_priv->pci_device, 1);
+	pr_info(" plx9050 base address 0x%lx\n", cec_priv->plx_iobase);
+	nec_priv->iobase = (void *)(pci_resource_start(cec_priv->pci_device, 3));
+	pr_info(" nec7210 base address 0x%p\n", nec_priv->iobase);
+
+	isr_flags |= IRQF_SHARED;
+	if (request_irq(cec_priv->pci_device->irq, cec_interrupt, isr_flags, "pci-gpib", board)) {
+		pr_err("gpib: can't request IRQ %d\n", cec_priv->pci_device->irq);
+		return -1;
+	}
+	cec_priv->irq = cec_priv->pci_device->irq;
+	if (gpib_request_pseudo_irq(board, cec_interrupt)) {
+		pr_err("cec: failed to allocate pseudo irq\n");
+		return -1;
+	}
+	cec_init(cec_priv, board);
+
+	// enable interrupts on plx chip
+	outl(PLX9050_LINTR1_EN_BIT | PLX9050_LINTR1_POLARITY_BIT | PLX9050_PCI_INTR_EN_BIT,
+	     cec_priv->plx_iobase + PLX9050_INTCSR_REG);
+
+	return 0;
+}
+
+void cec_pci_detach(gpib_board_t *board)
+{
+	struct cec_priv *cec_priv = board->private_data;
+	struct nec7210_priv *nec_priv;
+
+	if (cec_priv) {
+		nec_priv = &cec_priv->nec7210_priv;
+		gpib_free_pseudo_irq(board);
+		if (cec_priv->irq) {
+			// disable plx9050 interrupts
+			outl(0, cec_priv->plx_iobase + PLX9050_INTCSR_REG);
+			free_irq(cec_priv->irq, board);
+		}
+		if (nec_priv->iobase) {
+			nec7210_board_reset(nec_priv, board);
+			pci_release_regions(cec_priv->pci_device);
+		}
+		if (cec_priv->pci_device)
+			pci_dev_put(cec_priv->pci_device);
+	}
+	cec_free_private(board);
+}
+
+static int cec_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	return 0;
+}
+
+static const struct pci_device_id cec_pci_table[] = {
+	{CEC_VENDOR_ID, CEC_DEV_ID, PCI_ANY_ID, CEC_SUBID, 0, 0, 0 },
+	{0}
+};
+MODULE_DEVICE_TABLE(pci, cec_pci_table);
+
+static struct pci_driver cec_pci_driver = {
+	.name = "cec_gpib",
+	.id_table = cec_pci_table,
+	.probe = &cec_pci_probe
+};
+
+static int __init cec_init_module(void)
+{
+	int result;
+
+	result = pci_register_driver(&cec_pci_driver);
+	if (result) {
+		pr_err("cec_gpib: pci_driver_register failed!\n");
+		return result;
+	}
+
+	gpib_register_driver(&cec_pci_interface, THIS_MODULE);
+
+	return 0;
+}
+
+static void cec_exit_module(void)
+{
+	gpib_unregister_driver(&cec_pci_interface);
+
+	pci_unregister_driver(&cec_pci_driver);
+}
+
+module_init(cec_init_module);
+module_exit(cec_exit_module);