SPI slave devices require the specification of a chip select address.
This patch allows that specification using the gpios property. The reg
property remains supported.
Signed-off-by: Wolfgang Ocker <[EMAIL PROTECTED]>
---
--- linux-2.6.27.3/drivers/of/of_spi.c.of_spi_gpio 2008-10-22
23:38:01.000000000 +0200
+++ linux-2.6.27.3/drivers/of/of_spi.c.of_spi_cshigh 2008-10-24
21:36:39.000000000 +0200
@@ -10,6 +10,7 @@
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/of_spi.h>
+#include <linux/of_gpio.h>
/**
* of_register_spi_devices - Register child devices onto the SPI bus
@@ -24,6 +25,7 @@ void of_register_spi_devices(struct spi_
struct spi_device *spi;
struct device_node *nc;
const u32 *prop;
+ int cs_addr;
int rc;
int len;
@@ -48,13 +50,20 @@ void of_register_spi_devices(struct spi_
/* Device address */
prop = of_get_property(nc, "reg", &len);
- if (!prop || len < sizeof(*prop)) {
- dev_err(&master->dev, "%s has no 'reg' property\n",
- nc->full_name);
- spi_dev_put(spi);
- continue;
+ if (prop && len >= sizeof(*prop)) {
+ cs_addr = *prop;
+ }
+ else {
+ cs_addr = of_get_gpio(nc, 0);
+ if (cs_addr < 0) {
+ dev_err(&master->dev,
+ "%s has no 'reg' nor gpios property\n",
+ nc->full_name);
+ spi_dev_put(spi);
+ continue;
+ }
}
- spi->chip_select = *prop;
+ spi->chip_select = cs_addr;
/* Mode (clock phase/polarity/etc.) */
if (of_find_property(nc, "spi-cpha", NULL))
--- linux-2.6.27.3/Documentation/powerpc/booting-without-of.txt.of_spi_gpio
2008-10-22 23:38:01.000000000 +0200
+++ linux-2.6.27.3/Documentation/powerpc/booting-without-of.txt.of_spi_cshigh
2008-10-24 21:57:16.000000000 +0200
@@ -1909,7 +1909,9 @@ platforms are moved over to use the flat
SPI slave nodes must be children of the SPI master node and can
contain the following properties.
- - reg - (required) chip select address of device.
+ - reg - chip select address of device.
+ - gpios - chip select address of device (alternatively).
+ one of reg and gpios is required.
- compatible - (required) name of SPI device following generic names
recommended practice
- spi-max-frequency - (required) Maximum SPI clocking speed of device in Hz
@@ -1936,7 +1938,7 @@ platforms are moved over to use the flat
[EMAIL PROTECTED] {
compatible = "ti,tlv320aic26";
spi-max-frequency = <100000>;
- reg = <1>;
+ gpios = <&GPIO1 3>;
};
};
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