api: move a devicetree.h layering violation to drivers/spi.h

The DT_SPI_DEV_CS_GPIOS_DT_SPEC_GET macro belongs in drivers/spi.h,
not devicetree.h.

It is creating a struct gpio_dt_spec, but the devicetree.h API does
not (other than in this case) and should not depend on structures that
are defined in the GPIO API. This is because the GPIO API already
depends on the devicetree.h API, so making a dependency in the reverse
direction creates a needless circular dependency.

This macro should have been added to the drivers/spi.h API from the
beginning. Move it there under a new name, SPI_CS_GPIOS_DT_SPEC_GET.

We haven't created a Zephyr release with
DT_SPI_DEV_CS_GPIOS_DT_SPEC_GET in it, so there is no need to go
through the stable API change process for devicetree.h to deprecate
and eventually remove it. We can just remove it directly.

Fixes: zephyrproject-rtos#42149
Signed-off-by: Martí Bolívar <[email protected]>

Author: mbolivar-nordic

include/devicetree/spi.h

@@ -116,46 +116,6 @@ extern "C" {
  */
 #define DT_SPI_DEV_HAS_CS_GPIOS(spi_dev) DT_SPI_HAS_CS_GPIOS(DT_BUS(spi_dev))
 
-/**
- * @brief Get a SPI device's chip select devicetree specification
- *
- * Example devicetree fragment:
- *
- * @code{.devicetree}
- *     gpio1: gpio@... { ... };
- *
- *     gpio2: gpio@... { ... };
- *
- *     spi@... {
- *             compatible = "vnd,spi";
- *             cs-gpios = <&gpio1 10 GPIO_ACTIVE_LOW>,
- *                        <&gpio2 20 GPIO_ACTIVE_LOW>;
- *
- *             a: spi-dev-a@0 {
- *                     reg = <0>;
- *             };
- *
- *             b: spi-dev-b@1 {
- *                     reg = <1>;
- *             };
- *     };
- * @endcode
- *
- * Example usage:
- *
- * @code{.c}
- *     DT_SPI_DEV_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(a)) \
- *           // { DEVICE_DT_GET(DT_NODELABEL(gpio1)), 10, GPIO_ACTIVE_LOW }
- *     DT_SPI_DEV_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(b)) \
- *           // { DEVICE_DT_GET(DT_NODELABEL(gpio2)), 20, GPIO_ACTIVE_LOW }
- * @endcode
- *
- * @param spi_dev a SPI device node identifier
- * @return #gpio_dt_spec struct corresponding with spi_dev's chip select
- */
-#define DT_SPI_DEV_CS_GPIOS_DT_SPEC_GET(spi_dev) \
-	GPIO_DT_SPEC_GET_BY_IDX(DT_BUS(spi_dev), cs_gpios, DT_REG_ADDR(spi_dev))
-
 /**
  * @brief Get a SPI device's chip select GPIO controller's node identifier
  *

include/drivers/spi.h

@@ -164,6 +164,46 @@ struct spi_cs_control {
 	uint32_t delay;
 };
 
+/**
+ * @brief Get a <tt>struct gpio_dt_spec</tt> for a SPI device's chip select pin
+ *
+ * Example devicetree fragment:
+ *
+ * @code{.devicetree}
+ *     gpio1: gpio@... { ... };
+ *
+ *     gpio2: gpio@... { ... };
+ *
+ *     spi@... {
+ *             compatible = "vnd,spi";
+ *             cs-gpios = <&gpio1 10 GPIO_ACTIVE_LOW>,
+ *                        <&gpio2 20 GPIO_ACTIVE_LOW>;
+ *
+ *             a: spi-dev-a@0 {
+ *                     reg = <0>;
+ *             };
+ *
+ *             b: spi-dev-b@1 {
+ *                     reg = <1>;
+ *             };
+ *     };
+ * @endcode
+ *
+ * Example usage:
+ *
+ * @code{.c}
+ *     SPI_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(a)) \
+ *           // { DEVICE_DT_GET(DT_NODELABEL(gpio1)), 10, GPIO_ACTIVE_LOW }
+ *     SPI_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(b)) \
+ *           // { DEVICE_DT_GET(DT_NODELABEL(gpio2)), 20, GPIO_ACTIVE_LOW }
+ * @endcode
+ *
+ * @param spi_dev a SPI device node identifier
+ * @return #gpio_dt_spec struct corresponding with spi_dev's chip select
+ */
+#define SPI_CS_GPIOS_DT_SPEC_GET(spi_dev) \
+	GPIO_DT_SPEC_GET_BY_IDX(DT_BUS(spi_dev), cs_gpios, DT_REG_ADDR(spi_dev))
+
 #ifndef __cplusplus
 /**
  * @brief Initialize and get a pointer to a @p spi_cs_control from a
@@ -211,7 +251,7 @@ struct spi_cs_control {
  */
 #define SPI_CS_CONTROL_PTR_DT(node_id, delay_)			  \
 	(&(struct spi_cs_control) {				  \
-		.gpio = DT_SPI_DEV_CS_GPIOS_DT_SPEC_GET(node_id), \
+		.gpio = SPI_CS_GPIOS_DT_SPEC_GET(node_id), \
 		.delay = (delay_),				  \
 	})