1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 #ifndef __MACH_SPI_H_
4 #define __MACH_SPI_H_
5
6 /*
7 * struct spi_imx_master - device.platform_data for SPI controller devices.
8 * @chipselect: Array of chipselects for this master or NULL. Numbers >= 0
9 * mean GPIO pins, -ENOENT means internal CSPI chipselect
10 * matching the position in the array. E.g., if chipselect[1] =
11 * -ENOENT then a SPI slave using chip select 1 will use the
12 * native SS1 line of the CSPI. Omitting the array will use
13 * all native chip selects.
14
15 * Normally you want to use gpio based chip selects as the CSPI
16 * module tries to be intelligent about when to assert the
17 * chipselect: The CSPI module deasserts the chipselect once it
18 * runs out of input data. The other problem is that it is not
19 * possible to mix between high active and low active chipselects
20 * on one single bus using the internal chipselects.
21 * Unfortunately, on some SoCs, Freescale decided to put some
22 * chipselects on dedicated pins which are not usable as gpios,
23 * so we have to support the internal chipselects.
24 *
25 * @num_chipselect: If @chipselect is specified, ARRAY_SIZE(chipselect),
26 * otherwise the number of native chip selects.
27 */
28 struct spi_imx_master {
29 int *chipselect;
30 int num_chipselect;
31 };
32
33 #endif /* __MACH_SPI_H_*/