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>

diff --git a/arch/arm/boot/dts/imx28-tx28.dts b/arch/arm/boot/dts/imx28-tx28.dts
index cfe6b3148dcc79389e5493104920d3239f47175b..81d4eb4220a5e642e7a47dd7031561ba096e169f 100644 (file)
--- 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 */