xilinx-axi-i2c.h

/*
 * Copyright (c) 2016-2017 Chris Johns <chrisj@rtems.org>  All rights reserved.
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */
 
/*
 * Xilinx AXI IIC Interface v2.0. See PG090.pdf.
 *
 * Note, only master support is provided and no dynamic mode by design.
 *
 * The clock set up is to be handled by the IP integrator. There are too many
 * factors handling this in software.
 */
 
 
#ifndef XILINX_AXI_I2C_H
#define XILINX_AXI_I2C_H
 
#include <dev/i2c/i2c.h>
 
/*
 * The PL integrator controls the timing. This interface allows software to
 * override those settings. It pays to check the timing with ChipScope.
 *
 * If you set the AXI bus frequency you can use the clock speed ioctl call to
 * change the speed dymanically. The ioctl call overrides the defaults passed
 * in.
 *
 * Set the valid mask to the values that are to be set.
 */
#define XILINX_AIX_I2C_AXI_CLOCK (1 << 0)
#define XILINX_AIX_I2C_TSUSTA    (1 << 1)
#define XILINX_AIX_I2C_TSUSTO    (1 << 2)
#define XILINX_AIX_I2C_THDSTA    (1 << 3)
#define XILINX_AIX_I2C_TSUDAT    (1 << 4)
#define XILINX_AIX_I2C_TBUF      (1 << 5)
#define XILINX_AIX_I2C_THIGH     (1 << 6)
#define XILINX_AIX_I2C_TLOW      (1 << 7)
#define XILINX_AIX_I2C_THDDAT    (1 << 8)
#define XILINX_AIX_I2C_ALL_REGS  (XILINX_AIX_I2C_TSUSTA | \
                                  XILINX_AIX_I2C_TSUSTO | \
                                  XILINX_AIX_I2C_THDSTA | \
                                  XILINX_AIX_I2C_TSUDAT | \
                                  XILINX_AIX_I2C_TBUF   | \
                                  XILINX_AIX_I2C_THIGH  | \
                                  XILINX_AIX_I2C_TLOW   | \
                                  XILINX_AIX_I2C_THDDAT)
typedef struct
{
  uint32_t valid_mask;
  uint32_t AXI_CLOCK;
  uint32_t SCL_INERTIAL_DELAY;
  uint32_t TSUSTA;
  uint32_t TSUSTO;
  uint32_t THDSTA;
  uint32_t TSUDAT;
  uint32_t TBUF;
  uint32_t THIGH;
  uint32_t TLOW;
  uint32_t THDDAT;
} xilinx_aix_i2c_timing;
 
/*
 * Register the driver.
 *
 * The driver can multipex a number of I2C buses (in master mode only) using
 * the GPO port. The PL designer can use the output pins to select a bus. This
 * is useful if connecting a number of slave devices that have limit selectable
 * addresses.
 *
 * @param bus_path The driver's device path.
 * @param register_base AXI base address.
 * @param irq AXI FPGA interrupt.
 * @param gpio_address Bits 12:15 of a slave address it written to the GPO.
 * @param timing Override the default timing. NULL means no changes.
 */
int i2c_bus_register_xilinx_aix_i2c(const char*                  bus_path,
                                    uintptr_t                    register_base,
                                    rtems_vector_number          irq,
                                    bool                         ten_gpio,
                                    const xilinx_aix_i2c_timing* timing);
 
#endif