staging: gpib: Add Computer Boards GPIB driver

Driver for Computer Boards interface cards.

Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20240918121908.19366-11-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gpib/cb7210/Makefile

@@ -0,0 +1,4 @@
+ccflags-$(CONFIG_GPIB_PCMCIA) := -DGPIB_PCMCIA
+obj-m += cb7210.o
+
+

drivers/staging/gpib/cb7210/cb7210.h

@@ -0,0 +1,251 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/***************************************************************************
+ *    copyright            : (C) 2002 by Frank Mori Hess
+ ***************************************************************************/
+
+#include "nec7210.h"
+#include "gpibP.h"
+#include "amccs5933.h"
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+
+enum {
+	PCI_DEVICE_ID_CBOARDS_PCI_GPIB = 0x6,
+	PCI_DEVICE_ID_CBOARDS_CPCI_GPIB = 0xe,
+};
+
+enum pci_chip {
+	PCI_CHIP_NONE = 0,
+	PCI_CHIP_AMCC_S5933,
+	PCI_CHIP_QUANCOM
+};
+
+// struct which defines private_data for cb7210 boards
+struct cb7210_priv {
+	struct nec7210_priv nec7210_priv;
+	struct pci_dev *pci_device;
+	// base address of amccs5933 pci chip
+	unsigned long amcc_iobase;
+	unsigned long fifo_iobase;
+	unsigned int irq;
+	enum pci_chip pci_chip;
+	u8 hs_mode_bits;
+	unsigned out_fifo_half_empty : 1;
+	unsigned in_fifo_half_full : 1;
+};
+
+// interfaces
+extern gpib_interface_t cb_pcmcia_interface;
+extern gpib_interface_t cb_pcmcia_accel_interface;
+extern gpib_interface_t cb_pcmcia_unaccel_interface;
+
+// interrupt service routines
+irqreturn_t cb_pci_interrupt(int irq, void *arg);
+irqreturn_t cb7210_interrupt(int irq, void *arg);
+irqreturn_t cb7210_internal_interrupt(gpib_board_t *board);
+
+// interface functions
+int cb7210_read(gpib_board_t *board, uint8_t *buffer, size_t length,
+		int *end, size_t *bytes_read);
+int cb7210_accel_read(gpib_board_t *board, uint8_t *buffer, size_t length,
+		      int *end, size_t *bytes_read);
+int cb7210_write(gpib_board_t *board, uint8_t *buffer, size_t length,
+		 int send_eoi, size_t *bytes_written);
+int cb7210_accel_write(gpib_board_t *board, uint8_t *buffer, size_t length,
+		       int send_eoi, size_t *bytes_written);
+int cb7210_command(gpib_board_t *board, uint8_t *buffer, size_t length, size_t *bytes_written);
+int cb7210_take_control(gpib_board_t *board, int synchronous);
+int cb7210_go_to_standby(gpib_board_t *board);
+void cb7210_request_system_control(gpib_board_t *board, int request_control);
+void cb7210_interface_clear(gpib_board_t *board, int assert);
+void cb7210_remote_enable(gpib_board_t *board, int enable);
+int cb7210_enable_eos(gpib_board_t *board, uint8_t eos_byte,
+		      int compare_8_bits);
+void cb7210_disable_eos(gpib_board_t *board);
+unsigned int cb7210_update_status(gpib_board_t *board, unsigned int clear_mask);
+int cb7210_primary_address(gpib_board_t *board, unsigned int address);
+int cb7210_secondary_address(gpib_board_t *board, unsigned int address,
+			     int enable);
+int cb7210_parallel_poll(gpib_board_t *board, uint8_t *result);
+void cb7210_serial_poll_response(gpib_board_t *board, uint8_t status);
+uint8_t cb7210_serial_poll_status(gpib_board_t *board);
+void cb7210_parallel_poll_configure(gpib_board_t *board, uint8_t configuration);
+void cb7210_parallel_poll_response(gpib_board_t *board, int ist);
+int cb7210_line_status(const gpib_board_t *board);
+unsigned int cb7210_t1_delay(gpib_board_t *board, unsigned int nano_sec);
+void cb7210_return_to_local(gpib_board_t *board);
+
+// utility functions
+void cb7210_generic_detach(gpib_board_t *board);
+int cb7210_generic_attach(gpib_board_t *board);
+int cb7210_init(struct cb7210_priv *priv, gpib_board_t *board);
+
+// pcmcia init/cleanup
+int cb_pcmcia_init_module(void);
+void cb_pcmcia_cleanup_module(void);
+
+// pci-gpib register offset
+static const int cb7210_reg_offset = 1;
+
+// uses 10 ioports
+static const int cb7210_iosize = 10;
+
+// fifo size in bytes
+static const int cb7210_fifo_size = 2048;
+static const int cb7210_fifo_width = 2;
+
+// cb7210 specific registers and bits
+enum cb7210_regs {
+	BUS_STATUS = 0x7,
+};
+
+enum cb7210_page_in {
+	BUS_STATUS_PAGE = 1,
+};
+
+enum hs_regs {
+	//write registers
+	HS_MODE = 0x8,	/* HS_MODE register */
+	HS_INT_LEVEL = 0x9,	/* HS_INT_LEVEL register */
+	//read registers
+	HS_STATUS = 0x8,	/* HS_STATUS register */
+};
+
+static inline unsigned long nec7210_iobase(const struct cb7210_priv *cb_priv)
+{
+	return (unsigned long)(cb_priv->nec7210_priv.iobase);
+}
+
+static inline int cb7210_page_in_bits(unsigned int page)
+{
+	return 0x50 | (page & 0xf);
+}
+
+static inline uint8_t cb7210_paged_read_byte(struct cb7210_priv *cb_priv,
+					     unsigned int register_num, unsigned int page)
+{
+	struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;
+	u8 retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&nec_priv->register_page_lock, flags);
+	outb(cb7210_page_in_bits(page), nec7210_iobase(cb_priv) + AUXMR * nec_priv->offset);
+	udelay(1);
+	retval = inb(nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
+	spin_unlock_irqrestore(&nec_priv->register_page_lock, flags);
+	return retval;
+}
+
+// don't use for register_num < 8, since it doesn't lock
+static inline uint8_t cb7210_read_byte(const struct cb7210_priv *cb_priv,
+				       enum hs_regs register_num)
+{
+	const struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;
+	u8 retval;
+
+	retval = inb(nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
+	return retval;
+}
+
+static inline void cb7210_paged_write_byte(struct cb7210_priv *cb_priv, uint8_t data,
+					   unsigned int register_num, unsigned int page)
+{
+	struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;
+	unsigned long flags;
+
+	spin_lock_irqsave(&nec_priv->register_page_lock, flags);
+	outb(cb7210_page_in_bits(page), nec7210_iobase(cb_priv) + AUXMR * nec_priv->offset);
+	udelay(1);
+	outb(data, nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
+	spin_unlock_irqrestore(&nec_priv->register_page_lock, flags);
+}
+
+// don't use for register_num < 8, since it doesn't lock
+static inline void cb7210_write_byte(const struct cb7210_priv *cb_priv, uint8_t data,
+				     enum hs_regs register_num)
+{
+	const struct nec7210_priv *nec_priv = &cb_priv->nec7210_priv;
+
+	outb(data, nec7210_iobase(cb_priv) + register_num * nec_priv->offset);
+}
+
+enum bus_status_bits {
+	BSR_ATN_BIT = 0x1,
+	BSR_EOI_BIT = 0x2,
+	BSR_SRQ_BIT = 0x4,
+	BSR_IFC_BIT = 0x8,
+	BSR_REN_BIT = 0x10,
+	BSR_DAV_BIT = 0x20,
+	BSR_NRFD_BIT = 0x40,
+	BSR_NDAC_BIT = 0x80,
+};
+
+/* CBI 488.2 HS control */
+
+/* when both bit 0 and 1 are set, it
+ *   1 clears the transmit state machine to an initial condition
+ *   2 clears any residual interrupts left latched on cbi488.2
+ *   3 resets all control bits in HS_MODE to zero
+ *   4 enables TX empty interrupts
+ * when both bit 0 and 1 are zero, then the high speed mode is disabled
+ */
+enum hs_mode_bits {
+	HS_ENABLE_MASK = 0x3,
+	HS_TX_ENABLE = (1 << 0),
+	HS_RX_ENABLE = (1 << 1),
+	HS_HF_INT_EN = (1 << 3),
+	HS_CLR_SRQ_INT = (1 << 4),
+	HS_CLR_EOI_EMPTY_INT = (1 << 5),
+	HS_CLR_HF_INT = (1 << 6),
+	HS_SYS_CONTROL = (1 << 7),
+};
+
+/* CBI 488.2 status */
+enum hs_status_bits {
+	HS_FIFO_FULL = (1 << 0),
+	HS_HALF_FULL = (1 << 1),
+	HS_SRQ_INT = (1 << 2),
+	HS_EOI_INT = (1 << 3),
+	HS_TX_MSB_NOT_EMPTY = (1 << 4),
+	HS_RX_MSB_NOT_EMPTY = (1 << 5),
+	HS_TX_LSB_NOT_EMPTY = (1 << 6),
+	HS_RX_LSB_NOT_EMPTY = (1 << 7),
+};
+
+/* CBI488.2 hs_int_level register */
+enum hs_int_level_bits {
+	HS_RESET7210 = (1 << 7),
+};
+
+static inline unsigned int irq_bits(unsigned int irq)
+{
+	switch (irq) {
+	case 2:
+	case 3:
+	case 4:
+	case 5:
+		return irq - 1;
+	case 7:
+		return 0x5;
+	case 10:
+		return 0x6;
+	case 11:
+		return 0x7;
+	default:
+		return 0;
+	}
+}
+
+enum cb7210_aux_cmds {
+/* AUX_RTL2 is an undocumented aux command which causes cb7210 to assert
+ *	(and keep asserted) local rtl message.  This is used in conjunction
+ *	with the (stupid) cb7210 implementation
+ *	of the normal nec7210 AUX_RTL aux command, which
+ *	causes the rtl message to toggle between on and off.
+ */
+	AUX_RTL2 = 0xd,
+	AUX_LO_SPEED = 0x40,
+	AUX_HI_SPEED = 0x41,
+};