ARM: dts: imx28-tx28: add spi-gpio as alternative for spi-mxs

The spi-mxs driver does not allow full duplex SPI transfers. The
spi-gpio driver may be used as an alternative if this is required.

Make the choice between those drivers easier for the end user by
providing settings for both drivers.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/arch/arm/boot/dts/imx28-tx28.dts b/arch/arm/boot/dts/imx28-tx28.dts
index cfe6b3148dcc..81d4eb4220a5 100644
--- a/arch/arm/boot/dts/imx28-tx28.dts
+++ b/arch/arm/boot/dts/imx28-tx28.dts
@@ -27,6 +27,8 @@
                 lcdif = &lcdif;
                 lcdif_23bit_pins = &tx28_lcdif_23bit_pins;
                 lcdif_24bit_pins = &lcdif_24bit_pins_a;
+                spi_gpio = &spi_gpio;
+                spi_mxs = &ssp3;
                 stk5led = &user_led;
                 usbotg = &usb0;
         };
@@ -203,6 +205,44 @@
                 col-scan-delay-us = <5000>;
                 linux,no-autorepeat;
         };
+
+        spi_gpio: spi-gpio {
+                compatible = "spi-gpio";
+                #address-cells = <1>;
+                #size-cells = <0>;
+                pinctrl-names = "default";
+                pinctrl-0 = <&tx28_spi_gpio_pins>;
+
+                gpio-sck = <&gpio2 24 GPIO_ACTIVE_HIGH>;
+                gpio-mosi = <&gpio2 25 GPIO_ACTIVE_HIGH>;
+                gpio-miso = <&gpio2 26 GPIO_ACTIVE_HIGH>;
+                num-chipselects = <3>;
+                cs-gpios = <
+                        &gpio2 27 GPIO_ACTIVE_LOW
+                        &gpio3 8 GPIO_ACTIVE_LOW
+                        &gpio3 9 GPIO_ACTIVE_LOW
+                >;
+                /* enable this and disable ssp3 below, if you need full duplex SPI transfer */
+                status = "disabled";
+
+                spi@0 {
+                        compatible = "spidev";
+                        reg = <0>;
+                        spi-max-frequency = <57600000>;
+                };
+
+                spi@1 {
+                        compatible = "spidev";
+                        reg = <1>;
+                        spi-max-frequency = <57600000>;
+                };
+
+                spi@2 {
+                        compatible = "spidev";
+                        reg = <2>;
+                        spi-max-frequency = <57600000>;
+                };
+        };
 };
 
 /* 2nd TX-Std UART - (A)UART1  */
@@ -558,6 +598,20 @@
                 fsl,pull-up = <MXS_PULL_DISABLE>;
         };
 
+        tx28_spi_gpio_pins: spi-gpiogrp {
+                fsl,pinmux-ids = <
+                        MX28_PAD_AUART2_RX__GPIO_3_8
+                        MX28_PAD_AUART2_TX__GPIO_3_9
+                        MX28_PAD_SSP3_SCK__GPIO_2_24
+                        MX28_PAD_SSP3_MOSI__GPIO_2_25
+                        MX28_PAD_SSP3_MISO__GPIO_2_26
+                        MX28_PAD_SSP3_SS0__GPIO_2_27
+                >;
+                fsl,drive-strength = <MXS_DRIVE_8mA>;
+                fsl,voltage = <MXS_VOLTAGE_HIGH>;
+                fsl,pull-up = <MXS_PULL_DISABLE>;
+        };
+
         tx28_tsc2007_pins: tx28-tsc2007-pins {
                 fsl,pinmux-ids = <
                         MX28_PAD_SAIF0_MCLK__GPIO_3_20 /* TSC2007 IRQ */