shared/spi/imx-spi-gpio.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSDeviceIMXSPIGPIO
0007  *
0008  * @brief This file provides the implementation of @ref RTEMSDeviceIMXSPIGPIO.
0009  */
0010
0011 /*
0012  * Copyright (C) 2024 embedded brains GmbH & Co. KG
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #include <bsp/fatal.h>
0037 #include <bsp/fdt.h>
0038 #include <bsp/imx-gpio.h>
0039
0040 #include <dev/spi/spi.h>
0041 #include <libfdt.h>
0042 #include <dev/spi/spi-gpio.h>
0043 #include <dev/spi/imx-spi-gpio.h>
0044
0045 struct imx_spi_gpio_bus {
0046   spi_bus base;
0047   struct spi_gpio_params p;
0048
0049   struct imx_gpio_pin sck;
0050   struct imx_gpio_pin mosi;
0051   struct imx_gpio_pin miso;
0052   struct imx_gpio_pin cs[SPI_GPIO_MAX_CS];
0053 };
0054
0055 static void imx_spi_gpio_set(void *arg, bool level)
0056 {
0057   struct imx_gpio_pin *pin = arg;
0058   imx_gpio_set_output(pin, level ? 1 : 0);
0059 }
0060
0061 static bool imx_spi_gpio_get(void *arg)
0062 {
0063   struct imx_gpio_pin *pin = arg;
0064   return (imx_gpio_get_input(pin) != 0);
0065 }
0066
0067 rtems_status_code imx_spi_gpio_init(void)
0068 {
0069   const void *fdt;
0070   int node;
0071   rtems_status_code sc = RTEMS_SUCCESSFUL;
0072
0073   fdt = bsp_fdt_get();
0074   node = -1;
0075
0076   do {
0077     node = fdt_node_offset_by_compatible(fdt, node, "spi-gpio");
0078
0079     if (node >= 0 && imxrt_fdt_node_is_enabled(fdt, node)) {
0080       struct imx_spi_gpio_bus *bus;
0081       const char *bus_path;
0082       const uint32_t *val;
0083       int num_cs;
0084
0085       if (sc == RTEMS_SUCCESSFUL) {
0086         bus = (struct imx_spi_gpio_bus*) spi_bus_alloc_and_init(sizeof(*bus));
0087         if (bus == NULL) {
0088           sc = RTEMS_UNSATISFIED;
0089         }
0090       }
0091
0092       if (sc == RTEMS_SUCCESSFUL) {
0093         bus_path = fdt_getprop(fdt, node, "rtems,path", NULL);
0094         if (bus_path == NULL) {
0095           sc = RTEMS_UNSATISFIED;
0096         }
0097       }
0098
0099       if (sc == RTEMS_SUCCESSFUL) {
0100         sc = imx_gpio_init_from_fdt_property(
0101             &bus->sck, node, "sck-gpios", IMX_GPIO_MODE_OUTPUT, 0);
0102         bus->p.set_clk = imx_spi_gpio_set;
0103         bus->p.set_clk_arg = &bus->sck;
0104       }
0105
0106       if (sc == RTEMS_SUCCESSFUL) {
0107         sc = imx_gpio_init_from_fdt_property(
0108             &bus->miso, node, "miso-gpios", IMX_GPIO_MODE_INPUT, 0);
0109         bus->p.get_miso = imx_spi_gpio_get;
0110         bus->p.get_miso_arg = &bus->miso;
0111       }
0112
0113       if (sc == RTEMS_SUCCESSFUL) {
0114         sc = imx_gpio_init_from_fdt_property(
0115             &bus->mosi, node, "mosi-gpios", IMX_GPIO_MODE_OUTPUT, 0);
0116         bus->p.set_mosi = imx_spi_gpio_set;
0117         bus->p.set_mosi_arg = &bus->mosi;
0118       }
0119
0120       if (sc == RTEMS_SUCCESSFUL) {
0121         val = fdt_getprop(fdt, node, "num-chipselects", NULL);
0122         if (val != NULL) {
0123           ssize_t i;
0124
0125           num_cs = fdt32_to_cpu(val[0]);
0126
0127           for (i = 0; i < num_cs && sc == RTEMS_SUCCESSFUL; ++i) {
0128             sc = imx_gpio_init_from_fdt_property(
0129                 &bus->cs[i], node, "cs-gpios", IMX_GPIO_MODE_OUTPUT, 0);
0130             bus->p.set_cs[i] = imx_spi_gpio_set;
0131             bus->p.set_cs_arg[i] = &bus->cs[i];
0132             bus->p.cs_idle[i] = (imx_gpio_get_active_level(&bus->cs[i]) == 0);
0133           }
0134         }
0135       }
0136
0137       if (sc == RTEMS_SUCCESSFUL) {
0138         sc = spi_gpio_init(bus_path, &bus->p);
0139       }
0140
0141       if (sc != RTEMS_SUCCESSFUL && bus != NULL) {
0142         spi_bus_destroy_and_free(&bus->base);
0143       }
0144     }
0145   } while (node >= 0 && sc == RTEMS_SUCCESSFUL);
0146
0147   return sc;
0148 }