[rtems commit] bsps/xilinx_zynq: Add SPI driver for cadence-spi
Jan Sommer
jan at rtems.org
Wed Mar 10 19:13:51 UTC 2021
Module: rtems
Branch: master
Commit: cc825d0322ecdf67d3254da97b37d69fe7b6519c
Changeset: http://git.rtems.org/rtems/commit/?id=cc825d0322ecdf67d3254da97b37d69fe7b6519c
Author: Jan Sommer <jan.sommer at dlr.de>
Date: Wed Dec 2 13:30:03 2020 +0100
bsps/xilinx_zynq: Add SPI driver for cadence-spi
Updates #4320
---
bsps/include/dev/spi/cadence-spi-regs.h | 84 ++++++
bsps/include/dev/spi/cadence-spi.h | 63 +++++
bsps/shared/dev/spi/cadence-spi.c | 444 ++++++++++++++++++++++++++++++++
3 files changed, 591 insertions(+)
diff --git a/bsps/include/dev/spi/cadence-spi-regs.h b/bsps/include/dev/spi/cadence-spi-regs.h
new file mode 100644
index 0000000..b4b2366
--- /dev/null
+++ b/bsps/include/dev/spi/cadence-spi-regs.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * Copyright (C) 2021 Jan Sommer, German Aerospace Center (DLR)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LIBBSP_ARM_XILINX_ZYNQ_CADENCE_SPI_REGS_H
+#define LIBBSP_ARM_XILINX_ZYNQ_CADENCE_SPI_REGS_H
+
+#include <bsp/utility.h>
+
+typedef struct {
+ uint32_t config;
+#define CADENCE_SPI_CONFIG_MODEFAIL_EN BSP_BIT32(17)
+#define CADENCE_SPI_CONFIG_MANSTRT BSP_BIT32(16)
+#define CADENCE_SPI_CONFIG_MANSTRT_EN BSP_BIT32(15)
+#define CADENCE_SPI_CONFIG_MANUAL_CS BSP_BIT32(14)
+#define CADENCE_SPI_CONFIG_CS(val) BSP_FLD32(val, 10, 13)
+#define CADENCE_SPI_CONFIG_CS_GET(reg) BSP_FLD32GET(reg, 10, 13)
+#define CADENCE_SPI_CONFIG_CS_SET(reg, val) BSP_FLD32SET(reg, val, 10, 13)
+#define CADENCE_SPI_CONFIG_PERI_SEL BSP_BIT32(9)
+#define CADENCE_SPI_CONFIG_REF_CLK BSP_BIT32(8)
+#define CADENCE_SPI_CONFIG_BAUD_DIV(val) BSP_FLD32(val, 3, 5)
+#define CADENCE_SPI_CONFIG_BAUD_DIV_GET(reg) BSP_FLD32GET(reg, 3, 5)
+#define CADENCE_SPI_CONFIG_BAUD_DIV_SET(reg, val) BSP_FLD32SET(reg, val, 3, 5)
+#define CADENCE_SPI_CONFIG_CLK_PH BSP_BIT32(2)
+#define CADENCE_SPI_CONFIG_CLK_POL BSP_BIT32(1)
+#define CADENCE_SPI_CONFIG_MSTREN BSP_BIT32(0)
+ uint32_t irqstatus;
+ uint32_t irqenable;
+ uint32_t irqdisable;
+ uint32_t irqmask;
+#define CADENCE_SPI_IXR_TXUF BSP_BIT32(6)
+#define CADENCE_SPI_IXR_RXFULL BSP_BIT32(5)
+#define CADENCE_SPI_IXR_RXNEMPTY BSP_BIT32(4)
+#define CADENCE_SPI_IXR_TXFULL BSP_BIT32(3)
+#define CADENCE_SPI_IXR_TXOW BSP_BIT32(2)
+#define CADENCE_SPI_IXR_MODF BSP_BIT32(1)
+#define CADENCE_SPI_IXR_RXOVR BSP_BIT32(0)
+ uint32_t spienable;
+#define CADENCE_SPI_EN BSP_BIT32(0)
+ uint32_t delay;
+#define CADENCE_SPI_DELAY_DNSS(val) BSP_FLD32(val, 24, 31)
+#define CADENCE_SPI_DELAY_DNSS_GET(reg) BSP_FLD32GET(reg, 24, 31)
+#define CADENCE_SPI_DELAY_DNSS_SET(reg, val) BSP_FLD32SET(reg, val, 24, 31)
+#define CADENCE_SPI_DELAY_DBTWN(val) BSP_FLD32(val, 16, 23)
+#define CADENCE_SPI_DELAY_DBTWN_GET(reg) BSP_FLD32GET(reg, 16, 23)
+#define CADENCE_SPI_DELAY_DBTWN_SET(reg, val) BSP_FLD32SET(reg, val, 16, 23)
+#define CADENCE_SPI_DELAY_DAFTER(val) BSP_FLD32(val, 8, 15)
+#define CADENCE_SPI_DELAY_DAFTER_GET(reg) BSP_FLD32GET(reg, 8, 15)
+#define CADENCE_SPI_DELAY_DAFTER_SET(reg, val) BSP_FLD32SET(reg, val, 8, 15)
+#define CADENCE_SPI_DELAY_DINT(val) BSP_FLD32(val, 0, 7)
+#define CADENCE_SPI_DELAY_DINT_GET(reg) BSP_FLD32GET(reg, 0, 7)
+#define CADENCE_SPI_DELAY_DINT_SET(reg, val) BSP_FLD32SET(reg, val, 0, 7)
+ uint32_t txdata;
+ uint32_t rxdata;
+ uint32_t slave_idle_count;
+ uint32_t txthreshold;
+ uint32_t rxthreshold;
+ uint32_t moduleid;
+} cadence_spi;
+
+#endif /* LIBBSP_ARM_XILINX_ZYNQ_CADENCE_SPI_REGS_H */
diff --git a/bsps/include/dev/spi/cadence-spi.h b/bsps/include/dev/spi/cadence-spi.h
new file mode 100644
index 0000000..d97ede5
--- /dev/null
+++ b/bsps/include/dev/spi/cadence-spi.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * Copyright (C) 2021 Jan Sommer, German Aerospace Center (DLR)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LIBBSP_ARM_XILINX_ZYNQ_CADENCE_SPI_H
+#define LIBBSP_ARM_XILINX_ZYNQ_CADENCE_SPI_H
+
+#include <rtems.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * Register the cadence-spi device with rtems
+ *
+ * @param bus_path path of the new device (e.g. /dev/spi0)
+ * @register_base Address of the first (i.e. config) register
+ * @input_clock Configured frequency of the input clock
+ *
+ * @return RTEMS_SUCCESSFUL on success, negative number on failure
+ *
+ * Note: The spi frequencies the cadence spi device can achieve
+ * are the @p input_clock divided by a power of 2 between
+ * 4 and 256.
+ * The driver tries to find a divider which yields a spi
+ * frequency equal to or lower than the desired bus frequency.
+ */
+int spi_bus_register_cadence(
+ const char *bus_path,
+ uintptr_t register_base,
+ uint32_t input_clock,
+ rtems_vector_number irq
+);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* LIBBSP_ARM_XILINX_ZYNQ_CADENCE_SPI_H */
diff --git a/bsps/shared/dev/spi/cadence-spi.c b/bsps/shared/dev/spi/cadence-spi.c
new file mode 100644
index 0000000..c87289b
--- /dev/null
+++ b/bsps/shared/dev/spi/cadence-spi.c
@@ -0,0 +1,444 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * Copyright (C) 2021 Jan Sommer, German Aerospace Center (DLR)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include <bsp.h>
+
+#include <rtems/irq-extension.h>
+#include <sys/param.h> /* MAX() */
+
+#include <dev/spi/spi.h>
+#include <dev/spi/cadence-spi.h>
+#include <dev/spi/cadence-spi-regs.h>
+
+#define CADENCE_SPI_FIFO_SIZE 128
+#define CADENCE_SPI_MAX_CHIPSELECTS 3
+#define CADENCE_SPI_CS_NONE 0xF
+
+typedef struct cadence_spi_bus cadence_spi_bus;
+
+struct cadence_spi_bus {
+ spi_bus base;
+ volatile cadence_spi *regs;
+ uint32_t clk_in;
+ uint16_t clk_per_usecs;
+ uint32_t msg_todo;
+ const spi_ioc_transfer *msg;
+ uint32_t todo;
+ uint32_t in_transfer;
+ uint8_t *rx_buf;
+ const uint8_t *tx_buf;
+ rtems_id task_id;
+ rtems_vector_number irq;
+};
+
+
+static void cadence_spi_disable_interrupts(volatile cadence_spi *regs)
+{
+ regs->irqdisable = 0xffff;
+}
+
+static void cadence_spi_clear_irq_status(volatile cadence_spi *regs)
+{
+ regs->irqstatus = regs->irqstatus;
+}
+
+static bool cadence_spi_rx_fifo_not_empty(volatile cadence_spi *regs)
+{
+ return (regs->irqstatus & CADENCE_SPI_IXR_RXNEMPTY) != 0;
+}
+
+static void cadence_spi_reset(cadence_spi_bus *bus)
+{
+ volatile cadence_spi *regs = bus->regs;
+ uint32_t val;
+
+ cadence_spi_disable_interrupts(regs);
+
+ regs->spienable = 0;
+
+ val = regs->config;
+ val &= ~(CADENCE_SPI_CONFIG_MODEFAIL_EN
+ | CADENCE_SPI_CONFIG_MANSTRT_EN
+ | CADENCE_SPI_CONFIG_MANUAL_CS
+ | CADENCE_SPI_CONFIG_PERI_SEL
+ | CADENCE_SPI_CONFIG_REF_CLK);
+
+ val |= CADENCE_SPI_CONFIG_CS(CADENCE_SPI_CS_NONE)
+ | CADENCE_SPI_CONFIG_MSTREN
+ | CADENCE_SPI_CONFIG_MANSTRT;
+ regs->config = val;
+
+ /* Initialize here, will be set for every transfer */
+ regs->txthreshold = 1;
+ /* Set to 1, so we can check when the rx buffer is empty */
+ regs->rxthreshold = 1;
+
+ while (cadence_spi_rx_fifo_not_empty(regs)) {
+ regs->rxdata;
+ }
+ cadence_spi_clear_irq_status(regs);
+}
+
+static void cadence_spi_done(cadence_spi_bus *bus)
+{
+ volatile cadence_spi *regs = bus->regs;
+ regs->spienable = 0;
+ cadence_spi_disable_interrupts(regs);
+ cadence_spi_clear_irq_status(regs);
+ rtems_event_transient_send(bus->task_id);
+}
+
+static void cadence_spi_push(cadence_spi_bus *bus, volatile cadence_spi *regs)
+{
+ while (bus->todo > 0 && bus->in_transfer < CADENCE_SPI_FIFO_SIZE) {
+ uint8_t val = 0;
+ if (bus->tx_buf != NULL) {
+ val = *bus->tx_buf;
+ ++bus->tx_buf;
+ }
+
+ --bus->todo;
+ regs->txdata = val;
+ ++bus->in_transfer;
+ }
+}
+
+static void
+cadence_spi_set_chipsel(cadence_spi_bus *bus, uint32_t cs)
+{
+
+ volatile cadence_spi *regs = bus->regs;
+ uint32_t cs_bit = CADENCE_SPI_CS_NONE;
+ uint32_t config = regs->config;
+
+ if (cs != SPI_NO_CS && cs < CADENCE_SPI_MAX_CHIPSELECTS) {
+ cs_bit >>= (CADENCE_SPI_MAX_CHIPSELECTS - cs + 1);
+ }
+ config = CADENCE_SPI_CONFIG_CS_SET(config, cs_bit);
+ bus->base.cs = cs;
+
+ regs->config = config;
+}
+
+static uint32_t
+cadence_spi_baud_divider(cadence_spi_bus *bus,
+ uint32_t speed_hz)
+{
+ uint32_t div;
+ uint32_t clk_in;
+
+ clk_in = bus->clk_in;
+
+ div = clk_in / speed_hz;
+ div = fls((int) div);
+
+ if (clk_in > (speed_hz << div)) {
+ ++div;
+ }
+
+ /* The baud divider needs to be at least 4, i.e. 2^2 */
+ div = MAX(2, div);
+
+ /* 0b111 is the maximum possible divider value */
+ div = MIN(7, div-1);
+ return div;
+}
+
+static void cadence_spi_config(
+ cadence_spi_bus *bus,
+ volatile cadence_spi *regs,
+ uint32_t speed_hz,
+ uint32_t mode,
+ uint16_t delay_usecs,
+ uint8_t cs
+)
+{
+ spi_bus *base = &bus->base;
+ uint32_t config = regs->config;
+ uint32_t delay;
+
+ regs->spienable = 0;
+
+ if ((mode & SPI_CPHA) != 0) {
+ config |= CADENCE_SPI_CONFIG_CLK_PH;
+ } else {
+ config &= ~CADENCE_SPI_CONFIG_CLK_PH;
+ }
+
+ if ((mode & SPI_CPOL) != 0) {
+ config |= CADENCE_SPI_CONFIG_CLK_POL;
+ } else {
+ config &= ~CADENCE_SPI_CONFIG_CLK_POL;
+ }
+
+ config = CADENCE_SPI_CONFIG_BAUD_DIV_SET(config,
+ cadence_spi_baud_divider(bus, speed_hz));
+
+ regs->config = config;
+ cadence_spi_set_chipsel(bus, cs);
+
+ delay = regs->delay;
+ delay = CADENCE_SPI_DELAY_DBTWN_SET(delay, delay_usecs * bus->clk_per_usecs);
+ regs->delay = delay;
+
+ base->speed_hz = speed_hz;
+ base->mode = mode;
+ base->cs = cs;
+
+}
+
+static void
+cadence_spi_next_msg(cadence_spi_bus *bus, volatile cadence_spi *regs)
+{
+ if (bus->msg_todo > 0) {
+ const spi_ioc_transfer *msg;
+ spi_bus *base = &bus->base;
+
+ msg = bus->msg;
+
+ if (
+ msg->speed_hz != base->speed_hz
+ || msg->mode != base->mode
+ || msg->cs != base->cs
+ ) {
+ cadence_spi_config(
+ bus,
+ regs,
+ msg->speed_hz,
+ msg->mode,
+ msg->delay_usecs,
+ msg->cs
+ );
+ }
+
+ if ((msg->mode & SPI_NO_CS) != 0) {
+ cadence_spi_set_chipsel(bus, CADENCE_SPI_CS_NONE);
+ }
+
+ bus->todo = msg->len;
+ bus->rx_buf = msg->rx_buf;
+ bus->tx_buf = msg->tx_buf;
+ cadence_spi_push(bus, regs);
+
+ cadence_spi_disable_interrupts(regs);
+ if (bus->todo < CADENCE_SPI_FIFO_SIZE) {
+ /* if the msg fits into the FIFO for empty TX buffer */
+ regs->txthreshold = 1;
+
+ } else {
+ /* if the msg does not fit refill tx_buf when the threshold is hit */
+ regs->txthreshold = CADENCE_SPI_FIFO_SIZE / 2;
+ }
+ regs->irqenable = CADENCE_SPI_IXR_TXOW;
+ regs->spienable = 1;
+ } else {
+ cadence_spi_done(bus);
+ }
+}
+
+static void cadence_spi_interrupt(void *arg)
+{
+ cadence_spi_bus *bus;
+ volatile cadence_spi *regs;
+
+ bus = arg;
+ regs = bus->regs;
+
+ /* The RXNEMPTY flag is sometimes not cleared fast
+ * enough between 2 reads which could lead to
+ * reading an extra byte erroneously. Therefore,
+ * also check the in_transfer counter
+ */
+ while (cadence_spi_rx_fifo_not_empty(regs)
+ && bus->in_transfer > 0) {
+ uint32_t val = regs->rxdata;
+ if (bus->rx_buf != NULL) {
+ *bus->rx_buf = (uint8_t)val;
+ ++bus->rx_buf;
+ }
+ --bus->in_transfer;
+ }
+
+ if (bus->todo > 0) {
+ cadence_spi_push(bus, regs);
+ } else if (bus->in_transfer > 0) {
+ /* Wait until all bytes have been transfered */
+ regs->txthreshold = 1;
+ } else {
+ --bus->msg_todo;
+ ++bus->msg;
+ cadence_spi_next_msg(bus, regs);
+ }
+}
+
+static int cadence_spi_check_messages(
+ cadence_spi_bus *bus,
+ const spi_ioc_transfer *msg,
+ uint32_t size)
+{
+ while(size > 0) {
+ if (msg->bits_per_word != 8) {
+ return -EINVAL;
+ }
+ if ((msg->mode &
+ ~(SPI_CPHA | SPI_CPOL | SPI_NO_CS)) != 0) {
+ return -EINVAL;
+ }
+ if ((msg->mode & SPI_NO_CS) == 0 &&
+ (msg->cs > CADENCE_SPI_MAX_CHIPSELECTS)) {
+ return -EINVAL;
+ }
+
+ ++msg;
+ --size;
+ }
+
+ return 0;
+}
+
+static int cadence_spi_transfer(
+ spi_bus *base,
+ const spi_ioc_transfer *msgs,
+ uint32_t n
+)
+{
+ cadence_spi_bus *bus;
+ int rv;
+
+ bus = (cadence_spi_bus *) base;
+
+ rv = cadence_spi_check_messages(bus, msgs, n);
+
+ if (rv == 0) {
+ bus->msg_todo = n;
+ bus->msg = &msgs[0];
+ bus->task_id = rtems_task_self();
+
+ cadence_spi_next_msg(bus, bus->regs);
+ rtems_event_transient_receive(RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+ cadence_spi_set_chipsel(bus, CADENCE_SPI_CS_NONE);
+ }
+ return rv;
+}
+
+static void cadence_spi_destroy(spi_bus *base)
+{
+ cadence_spi_bus *bus;
+
+ bus = (cadence_spi_bus *) base;
+ rtems_interrupt_handler_remove(bus->irq, cadence_spi_interrupt, bus);
+ spi_bus_destroy_and_free(&bus->base);
+}
+
+static int cadence_spi_setup(spi_bus *base)
+{
+ cadence_spi_bus *bus;
+ uint32_t mode = base->mode;
+
+ bus = (cadence_spi_bus *) base;
+
+ /* Baud rate divider is at least 4 and at most 256 */
+ if (
+ base->speed_hz > base->max_speed_hz
+ || base->speed_hz < (bus->clk_in / 256)
+ || bus->base.bits_per_word > 8
+ ) {
+ return -EINVAL;
+ }
+
+ /* SPI_CS_HIGH and SPI_LOOP not supported */
+ if ((mode & SPI_CS_HIGH) || (mode & SPI_LOOP)) {
+ return -EINVAL;
+ }
+
+ cadence_spi_config(
+ bus,
+ bus->regs,
+ base->speed_hz,
+ base->mode,
+ base->delay_usecs,
+ base->cs
+ );
+ return 0;
+}
+
+int spi_bus_register_cadence(const char *bus_path,
+ uintptr_t register_base,
+ uint32_t input_clock,
+ rtems_vector_number irq)
+{
+ cadence_spi_bus *bus;
+ spi_bus *base;
+ int sc;
+
+ bus = (cadence_spi_bus *) spi_bus_alloc_and_init(sizeof(*bus));
+ if (bus == NULL){
+ return -1;
+ }
+
+ base = &bus->base;
+ bus->regs = (volatile cadence_spi *) register_base;
+ bus->clk_in = input_clock;
+ bus->clk_per_usecs = input_clock / 1000000;
+ bus->irq = irq;
+
+ /* The minimum clock divider is 4 */
+ base->max_speed_hz = (input_clock + 3) / 4;
+ base->delay_usecs = 0;
+ base->speed_hz = base->max_speed_hz;
+ base->cs = SPI_NO_CS;
+
+ cadence_spi_reset(bus);
+ cadence_spi_config(
+ bus,
+ bus->regs,
+ base->speed_hz,
+ base->mode,
+ base->delay_usecs,
+ base->cs
+ );
+
+
+ sc = rtems_interrupt_handler_install(
+ bus->irq,
+ "CASPI",
+ RTEMS_INTERRUPT_UNIQUE,
+ cadence_spi_interrupt,
+ bus
+ );
+ if (sc != RTEMS_SUCCESSFUL) {
+ (*bus->base.destroy)(&bus->base);
+ rtems_set_errno_and_return_minus_one(EAGAIN);
+ }
+
+ bus->base.transfer = cadence_spi_transfer;
+ bus->base.destroy = cadence_spi_destroy;
+ bus->base.setup = cadence_spi_setup;
+
+ return spi_bus_register(&bus->base, bus_path);
+}
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