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This article shows how to enable the SPI1 interface (with CS0 and CS1 chip selects) which can be used in a standard Linux application.
=== Pin Mux Option ===
SPI1 signals are available at different Diva pins. We chose the following configuration:
{|class="wikitable" style="text-align:right"
!| Signal
!Diva Connector Phisical Pin
!CPU Ball
|-
|SPI1_SCLK
|J1.109
|C18
|-
|SPI1_D0
|J1.31
|E18
|-
|SPI1_D1
|J1.29
|E17
|-
|SPI1_CS0
|J1.144
|C12
|-
|SPI1_CS1
|J1.69
|A15
|}
=== Linux kernel patches ===
{{ImportantMessage|text=The patches below applies to DIVELK 1.0.0 Linux source tree.}}
The files <code>arch/arm/mach-omap2/board-diva.c</code> and <code>arch/arm/mach-omap2/diva_pinmux_table.h</code> must be modified according to the following patches:
<diff>
diff --git a/arch/arm/mach-omap2/board-diva.c b/arch/arm/mach-omap2/board-diva.c
index f6b77fc..a8b3996 100644
--- a/arch/arm/mach-omap2/board-diva.c
+++ b/arch/arm/mach-omap2/board-diva.c
@@ -356,6 +356,30 @@ static void spi0_init(int evm_id, int profile)
ARRAY_SIZE(diva_spi0_slave_info));
}
+/* -------------- SPI 1 Platform Data -----------------------------*/
+struct spi_board_info __initdata diva_spi1_slave_info[] = {
+ {
+ .modalias = "spidev",
+ .max_speed_hz = 2000000, /* max spi clock (SCK) speed in HZ */
+ .bus_num = 2,
+ .chip_select = 0,
+ },
+ {
+ .modalias = "spidev",
+ .max_speed_hz = 2000000, /* max spi clock (SCK) speed in HZ */
+ .bus_num = 2,
+ .chip_select = 1,
+ },
+};
+
+/* setup spi0 */
+
+static void spi1_init(int evm_id, int profile)
+{
+ setup_pin_mux(spi1_pin_mux);
+ spi_register_board_info(diva_spi1_slave_info,
+ ARRAY_SIZE(diva_spi1_slave_info));
+}
/* ----------- NAND Init ---------------------------------------*/
@@ -878,6 +902,7 @@ static struct evm_dev_cfg diva_dev_cfg[] = {
{mmc0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{rmii1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{spi0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
+ {spi1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{usb0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{usb1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
</diff>
<diff>
diff --git a/arch/arm/mach-omap2/diva_pinmux_table.h b/arch/arm/mach-omap2/diva_pinmux_table.h
index 5a2646a..9509b46 100644
--- a/arch/arm/mach-omap2/diva_pinmux_table.h
+++ b/arch/arm/mach-omap2/diva_pinmux_table.h
@@ -180,6 +180,21 @@ static struct pinmux_config w1_gpio_pin_mux[] = {
{NULL, 0},
};
+/* Module pin mux for SPI fash */
+static struct pinmux_config spi1_pin_mux[] = {
+ {"ecap0_in_pwm0_out.spi1_sclk", OMAP_MUX_MODE0 | AM33XX_PULL_ENBL
+ | AM33XX_INPUT_EN},
+ {"uart0_ctsn.spi1_d0", OMAP_MUX_MODE0 | AM33XX_PULL_ENBL | AM33XX_PULL_UP
+ | AM33XX_INPUT_EN},
+ {"uart0_rtsn.spi1_d1", OMAP_MUX_MODE0 | AM33XX_PULL_ENBL
+ | AM33XX_INPUT_EN},
+ {"mcasp0_ahclkr.spi1_cs0", OMAP_MUX_MODE0 | AM33XX_PULL_ENBL | AM33XX_PULL_UP
+ | AM33XX_INPUT_EN},
+ {"xdma_event_intr0.spi1_cs1", OMAP_MUX_MODE0 | AM33XX_PULL_ENBL | AM33XX_PULL_UP
+ | AM33XX_INPUT_EN},
+ {NULL, 0},
+};
+
/*
* the following mux configurations are un-tested but are left here for
* reference. They are all comment-out to avoid "defined but not used" warning
</diff>
The kernel must be rebuilt to make these modifications effective.
=== Using the interface ===
Users can access the peripherals connected to the SP1 bus through the <code>spidev</code> interface
=== Download patch ===