Enabling SPI1 on Linux (Diva)
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Contents
Introduction[edit | edit source]
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[edit | edit source]
SPI1 signals are available at different Diva pins. The following configurations can be used:
Option 1[edit | edit source]
| 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 |
Option 2[edit | edit source]
 This configuration can be implemented on the DivaEVB-Lite using the on-board expansion connectors. |
| Signal | Diva Connector Phisical Pin | CPU Ball | DivaEVB-Lite signal |
|---|---|---|---|
| SPI1_SCLK | J1.150 | A13 | J10.7 |
| SPI1_D0 | J1.140 | B13 | J9.15 |
| SPI1_D1 | J1.142 | D12 | J9.17 |
| SPI1_CS0 | J1.144 | C12 | J9.19 |
| SPI1_CS1 | J1.69 | A15 | J11.19 |
Linux kernel patches[edit | edit source]
|
The patches below applies to DIVELK 1.0.0 Linux source tree. |
Option 1[edit | edit source]
The files arch/arm/mach-omap2/board-diva.c and arch/arm/mach-omap2/diva_pinmux_table.h must be modified according to the following patches:
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 --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
The kernel must be rebuilt to make these modifications effective.
Option 2[edit | edit source]
The files arch/arm/mach-omap2/board-diva.c and arch/arm/mach-omap2/diva_pinmux_table.h must be modified according to the following patches:
diff --git a/arch/arm/mach-omap2/board-diva.c b/arch/arm/mach-omap2/board-diva.c
index 42898e9..8f7810d 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 spi1 */
+
+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 ---------------------------------------*/
@@ -872,11 +896,12 @@ 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},
{mfd_tscadc_init, DEV_ON_BASEBOARD, PROFILE_NONE},
- {mcasp0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
+ //{mcasp0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{w1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
|
With this pinmux configuration, the SPI1 signals are shared with the McASP0 signals. Thus, for a proper setup, the MCASP0 interface initialization must be disabled in |
diff --git a/arch/arm/mach-omap2/diva_pinmux_table.h b/arch/arm/mach-omap2/diva_pinmux_table.h
index f6647b0..d2722a3 100644
--- a/arch/arm/mach-omap2/diva_pinmux_table.h
+++ b/arch/arm/mach-omap2/diva_pinmux_table.h
@@ -179,6 +179,19 @@ static struct pinmux_config w1_gpio_pin_mux[] = {
{NULL, 0},
};
+/* Module pin mux for SPI1 */
+
+
+static struct pinmux_config spi1_pin_mux[] = {
+ {"mcasp0_aclkx.spi1_sclk", OMAP_MUX_MODE3 | AM33XX_PULL_ENBL | AM33XX_INPUT_EN}, // clock
+ {"mcasp0_fsx.spi1_d0", OMAP_MUX_MODE3 | AM33XX_PULL_ENBL | AM33XX_PULL_UP | AM33XX_INPUT_EN}, // d0
+ {"mcasp0_axr0.spi1_d1", OMAP_MUX_MODE3 | AM33XX_PULL_ENBL | AM33XX_INPUT_EN}, // d1
+ {"mcasp0_ahclkr.spi1_cs0", OMAP_MUX_MODE3 | AM33XX_PULL_ENBL | AM33XX_PULL_UP | AM33XX_INPUT_EN}, // cs0
+ {"xdma_event_intr0.spi1_cs1", OMAP_MUX_MODE4 | AM33XX_PULL_ENBL | AM33XX_PULL_UP | AM33XX_INPUT_EN}, // cs1
+ {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
@@ -187,7 +200,7 @@ static struct pinmux_config w1_gpio_pin_mux[] = {
#ifdef UNUSED_DIVA_PINMUX
/* Module pin mux for SPI flash */
-static struct pinmux_config spi1_pin_mux[] = {
+/*static struct pinmux_config spi1_pin_mux[] = {
{"mcasp0_aclkx.spi1_sclk", OMAP_MUX_MODE3 | AM33XX_PULL_ENBL
| AM33XX_INPUT_EN},
{"mcasp0_fsx.spi1_d0", OMAP_MUX_MODE3 | AM33XX_PULL_ENBL
@@ -197,7 +210,7 @@ static struct pinmux_config spi1_pin_mux[] = {
{"mcasp0_ahclkr.spi1_cs0", OMAP_MUX_MODE3 | AM33XX_PULL_ENBL
| AM33XX_PULL_UP | AM33XX_INPUT_EN},
{NULL, 0},
-};
+};*/
/* Module pin mux for rgmii1 */
static struct pinmux_config rgmii1_pin_mux[] = {
The kernel must be rebuilt to make these modifications effective.
Using the interface[edit | edit source]
Users can access the peripherals connected to the SP1 bus through the spidev interface. For further information, please refer to
- https://www.kernel.org/doc/Documentation/spi/spidev
- https://www.kernel.org/doc/Documentation/spi/spidev_test.c
Patch download[edit | edit source]
- Option 1: File:Divelk-spi1-enable.patch.zip
- Option 2: File:Divelk-spi1-enable-divaevb-lite.patch.zip
