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spi/atmel: add DT support 

Use the newly introduce cs-gpios dt support on atmel.
We do not use the hardware cs as it's wired and has bugs and limitations.
As the controller believes that only active-low devices/systems exists.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Jean-Christophe PLAGNIOL-VILLARD 2012-11-23 13:44:39 +01:00 committed by Grant Likely
parent cb71941a68
commit 850a5b670a
2 changed files with 42 additions and 1 deletions
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26
Documentation/devicetree/bindings/spi/spi_atmel.txt Normal file
View File

@ -0,0 +1,26 @@
Atmel SPI device
Required properties:
- compatible : should be "atmel,at91rm9200-spi".
- reg: Address and length of the register set for the device
- interrupts: Should contain spi interrupt
- cs-gpios: chipselects
Example:
spi1: spi@fffcc000 {
compatible = "atmel,at91rm9200-spi";
reg = <0xfffcc000 0x4000>;
interrupts = <13 4 5>;
#address-cells = <1>;
#size-cells = <0>;
cs-gpios = <&pioB 3 0>;
status = "okay";
mmc-slot@0 {
compatible = "mmc-spi-slot";
reg = <0>;
gpios = <&pioC 4 0>; /* CD */
spi-max-frequency = <25000000>;
};
};

17
drivers/spi/spi-atmel.c
View File

@ -20,6 +20,7 @@
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/platform_data/atmel.h>
#include <linux/of.h>
#include <asm/io.h>
#include <asm/gpio.h>
@ -768,6 +769,10 @@ static int atmel_spi_setup(struct spi_device *spi)
/* chipselect must have been muxed as GPIO (e.g. in board setup) */
npcs_pin = (unsigned int)spi->controller_data;
if (gpio_is_valid(spi->cs_gpio))
npcs_pin = spi->cs_gpio;
asd = spi->controller_state;
if (!asd) {
asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
@ -937,8 +942,9 @@ static int atmel_spi_probe(struct platform_device *pdev)
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->dev.of_node = pdev->dev.of_node;
master->bus_num = pdev->id;
master->num_chipselect = 4;
master->num_chipselect = master->dev.of_node ? 0 : 4;
master->setup = atmel_spi_setup;
master->transfer = atmel_spi_transfer;
master->cleanup = atmel_spi_cleanup;
@ -1064,11 +1070,20 @@ static int atmel_spi_resume(struct platform_device *pdev)
#define atmel_spi_resume NULL
#endif
#if defined(CONFIG_OF)
static const struct of_device_id atmel_spi_dt_ids[] = {
{ .compatible = "atmel,at91rm9200-spi" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
#endif
static struct platform_driver atmel_spi_driver = {
.driver = {
.name = "atmel_spi",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(atmel_spi_dt_ids),
},
.suspend = atmel_spi_suspend,
.resume = atmel_spi_resume,