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>

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>
Jean-Christophe PLAGNIOL-VILLARD · Grant Likely
1 parent cb71941a68
Showing 2 changed files with 42 additions and 1 deletions Side-by-side Diff
Documentation/devicetree/bindings/spi/spi_atmel.txt
drivers/spi/spi-atmel.c
+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>;
+	};
+};
@@ -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 @@
  
 	/* 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 @@
 	/* 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 @@
 #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,
	1	+Atmel SPI device
	2	+
	3	+Required properties:
	4	+- compatible : should be "atmel,at91rm9200-spi".
	5	+- reg: Address and length of the register set for the device
	6	+- interrupts: Should contain spi interrupt
	7	+- cs-gpios: chipselects
	8	+
	9	+Example:
	10	+
	11	+spi1: spi@fffcc000 {
	12	+ compatible = "atmel,at91rm9200-spi";
	13	+ reg = <0xfffcc000 0x4000>;
	14	+ interrupts = <13 4 5>;
	15	+ #address-cells = <1>;
	16	+ #size-cells = <0>;
	17	+ cs-gpios = <&pioB 3 0>;
	18	+ status = "okay";
	19	+
	20	+ mmc-slot@0 {
	21	+ compatible = "mmc-spi-slot";
	22	+ reg = <0>;
	23	+ gpios = <&pioC 4 0>; /* CD */
	24	+ spi-max-frequency = <25000000>;
	25	+ };
	26	+};
...	...	@@ -20,6 +20,7 @@
20	20	#include <linux/spi/spi.h>
21	21	#include <linux/slab.h>
22	22	#include <linux/platform_data/atmel.h>
	23	+#include <linux/of.h>
23	24
24	25	#include <asm/io.h>
25	26	#include <asm/gpio.h>
...	...	@@ -768,6 +769,10 @@
768	769
769	770	/* chipselect must have been muxed as GPIO (e.g. in board setup) */
770	771	npcs_pin = (unsigned int)spi->controller_data;
	772	+
	773	+ if (gpio_is_valid(spi->cs_gpio))
	774	+ npcs_pin = spi->cs_gpio;
	775	+
771	776	asd = spi->controller_state;
772	777	if (!asd) {
773	778	asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
774	779
...	...	@@ -937,8 +942,9 @@
937	942	/* the spi->mode bits understood by this driver: */
938	943	master->mode_bits = SPI_CPOL \| SPI_CPHA \| SPI_CS_HIGH;
939	944
	945	+ master->dev.of_node = pdev->dev.of_node;
940	946	master->bus_num = pdev->id;
941		- master->num_chipselect = 4;
	947	+ master->num_chipselect = master->dev.of_node ? 0 : 4;
942	948	master->setup = atmel_spi_setup;
943	949	master->transfer = atmel_spi_transfer;
944	950	master->cleanup = atmel_spi_cleanup;
945	951
946	952
...	...	@@ -1064,11 +1070,20 @@
1064	1070	#define atmel_spi_resume NULL
1065	1071	#endif
1066	1072
	1073	+#if defined(CONFIG_OF)
	1074	+static const struct of_device_id atmel_spi_dt_ids[] = {
	1075	+ { .compatible = "atmel,at91rm9200-spi" },
	1076	+ { /* sentinel */ }
	1077	+};
1067	1078
	1079	+MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
	1080	+#endif
	1081	+
1068	1082	static struct platform_driver atmel_spi_driver = {
1069	1083	.driver = {
1070	1084	.name = "atmel_spi",
1071	1085	.owner = THIS_MODULE,
	1086	+ .of_match_table = of_match_ptr(atmel_spi_dt_ids),
1072	1087	},
1073	1088	.suspend = atmel_spi_suspend,
1074	1089	.resume = atmel_spi_resume,