设备树的使用与调试

device/config/chips/${chip}/configs/${borad}/board.dts

cdts

TARGET_CHIP=xxx

device/config/chips/${chip}/configs/${borad}/board.dts

说明
注，对应图中为 sun50iw1p1.dts ， .dts 与 .dtsi 的区别在于 dtsi 是 dts 公共部分的提炼，应用时 dts 包含 dtsi 即可。
在本文中并不作严格区分。

优先级别最高，sys_config.fex跟devicetree文件都存在配置项时，sys_config.fex的配置
项内容会更新到board级配置文件或者soc级配置文件对应的配置项上去。

soc级定义：
/｛
soc {
thermal-zones {
xxx {
aaa = "1";
bbb = "2";
}
}
}
｝
board级定义：
/｛
soc {
thermal-zones {
xxx {
aaa = "3";
ccc = "4";
}
}
}
｝
最终生成：
/｛
soc {
thermal-zones {
xxx {
aaa = "3";

bbb = "2";
ccc = "4";
}
}
}
｝

soc级定义：
/｛
soc {
thermal-zones {
xxx {
aaa = "1";
bbb = "2";
}
}
}
｝
board级定义：
/｛
soc {
/delete-node/ thermal-zones;
thermal-zones {
xxx {
aaa = "3";
ccc = "4";
}
}
}
｝
最终生成：
/｛
soc {
thermal-zones {
xxx {
aaa = "3";
ccc = "4";
}
}
}
｝

/delete-node/ 节点名；

/delete-property/属性名；

Vdevice: vdevice@0{ (详见(1))：(详见(2))
compatible=”allwinner,sun50i-vdevice”;
device_type=”Vdevice”; (详见(3))
pinctrl_name=”default”; (详见(4))
pinctrl_0=<&vdevice_pins_a>
test_prop=”adb” (详见(5))
status=”okay” (详见(6))
};

#include<linux/of.h>
#include<linux/of_address.h>
#include<linux/of_irq.h>
#include<linux/of_gpio.h>

函数原型 unsigned int irq_of_parse_and_map(struct device_node
*dev, int index)
参数 dev：要解析中断号的设备；index：dts源文件中节点
interrupt属性值索引；
返回 如果解析成功，返回中断号，否则返回 0 。

以timer节点为例子：
Dts配置：
/{
timer0: timer@1c20c00 {
...
interrupts = <GIC_SPI 18 IRQ_TYPE_EDGE_RISING>;
...
};
};
驱动代码片段：
static void __init sunxi_timer_init(struct device_node *node){
int irq;
....
irq = irq_of_parse_and_map(node, 0);
if (irq <= 0)
panic("Can't parse IRQ");
}

以timer节点为例子，dts配置：
/{
timer0: timer@1c20c00 {
reg = <0x0 0x01c20c00 0x0 0x90>;
};
};
以timer为例子，驱动代码片段：
static void __init sunxi_timer_init(struct device_node *node){
timer_base = of_iomap(node, 0);
}

//以timer节点为例子，dts配置例子：
/{
soc_timer0: timer@1c20c00 {
clock-frequency = <24000000>;
timer-prescale = <16>;

};
};
//以timer节点为例子，驱动中获取clock-frequency属性值的例子：
int rate=0;
if (of_property_read_u32(node, "clock-frequency", &rate)) {
pr_err("<%s> must have a clock-frequency property\n",node->name);
return;
}

//例如获取string-prop的属性值，Dts配置：
/{
soc@01c20800{
vdevice: vdevice@0{
string_prop = "abcd";
};
};
};
例示代码：
test{
const char *name;
err = of_property_read_string(np, "string_prop", &name);
if (WARN_ON(err))
return;
}

//例如获取string-prop的属性值，Dts配置：
/{
soc@01c20800{
vdevice: vdevice@0{
string_prop = "abcd";
};
};
};
例示代码：
test{
const char *name;
err = of_property_read_string_index(np, "string_prop", 0, &name);
if (WARN_ON(err))
return;
}

//获取名字为vdeivce的节点，dts配置
/{
soc@01c20800{
vdevice: vdevice@0{
string_prop = "abcd";
};
};
};
例示代码片段：
test{
struct device_node *node;
node = of_find_node_by_name(NULL, "vdevice");
if (!node){
pr_warn("can not get node.\n");
};
of_node_put(node);
}

//获取名字为vdeivce的节点，dts配置。
/{
soc@01c20800{
vdevice: vdevice@0{
...
device_type = "vdevice";
string_prop = "abcd";
};
};
};
例示代码片段：
test{
struct device_node *node;
....
node = of_find_node_by_type(NULL, "vdevice");

if (!node){
pr_warn("can not get node.\n");
};
of_node_put(node);
}

//获取名字为vdeivce的节点，dts配置。
/{
soc@01c20800{
vdevice: vdevice@0{
device_type = "vdevice";
string_prop = "abcd";
};
};
};
例示代码片段：
test{
struct device_node *node;
node = of_find_node_by_path("/soc@01c2000/vdevice@0");
if (!node){
pr_warn("can not get node.\n");
};
of_node_put(node);
}

//获取名字为vdeivce的节点，dts配置。
/{
soc@01c20800{
vdevice: vdevice@0{
...
device_type = "vdevice";
string_prop = "abcd";
};
};
};
例示代码片段：
test{
struct device_node *node;
....
node = of_find_node_by_path("/soc@01c2000/vdevice@0");
if (!node){
pr_warn("can not get node.\n");
};
of_node_put(node);
}
/{
soc@01c20800{
vdevice: vdevice@0{
...
test-gpios=<&pio PA 1 1 1 1 0>;
};
};
};
static int gpio_test(struct platform_device *pdev)
{
struct gpio_config config;
....
node=of_find_node_by_type(NULL, "vdevice");
if(!node){
printk(" can not find node\n");
}
ret = of_get_named_gpio_flags(node, "test-gpios", 0, (enum of_gpio_flags *)&config)
;
if (!gpio_is_valid(ret)) {
return -EINVAL;
}
};

/*
device config in dts:
/{
soc@01c20000{
vdevice@0{
compatible = "allwinner,sun50i-vdevice";
device_type= "vdevice";
vdevice_0=<&pio 1 1 1 1 1 0>;
vdevice_1=<&pio 1 2 1 1 1 0>;
vdevice-prop-1=<0x1234>;
vdevice-prop-3="device-string";
status = "okay";
};
};
};

device config in sys_config.fex
[vdevice]
compatible = "allwinner,sun50i-vdevice";
vdevice_used = 1
vdevice_0 = port:PB01<1><1><2><default>
vdevice_1 = port:PB02<1><1><2><default>
vdevice-prop-1 = 0x1234

vdevice-prop-3 = "device-string"
*/

vdevice_0=<&pio 1 1 1 1 1 0>;
| | | | | | | |-------------------电平
| | | | | | |----------------------上下拉
| | | | | |-------------------------驱动力
| | | | |----------------------------复用类型，0-GPIOIN 1-GPIOOUT..
| | | |------------------------------pin bank内偏移.
| | |---------------------------------哪个bank，PA=0，PB=1...以此类推
| |--------------------------------------指向哪个pio，属于cpus要用&r_pio
|-----------------------------------------------------属性名字，相当sys_config子键名

#include <linux/sys_config.h>
int get_subkey_value_int(void)
{
script_item_u script_val;
script_item_value_type_e type;
type = script_get_item("vdevice", "vdevice-prop-1", &script_val);
if (SCIRPT_ITEM_VALUE_TYPE_INT != type) {
return -EINVAL;
}
return 0;
}

#include <linux/of.h>
int get_subkey_value_int(void)
{
int ret;
u32 value;
struct device_node *node;
node = of_find_node_by_type(NULL,"vdevice");
if(!node){
return -EINVAL;
}
ret = of_property_read_u32(node, "vdevice-prop-1", &value);
if(ret){
return -EINVAL;
}
printk("prop-value=%x\n", value);
return 0;
}

#include <linux/sys_config.h>
int get_subkey_value_string(void)
{
script_item_u script_val;
script_item_value_type_e type;
type = script_get_item("vdevice", "vdevice-prop-3", &script_val);
if (SCIRPT_ITEM_VALUE_TYPE_STR!= type) {
return -EINVAL;
}
return 0;
}

#include <linux/of.h>
int get_subkey_value_string(void)
{
int ret;
const char *string;
struct device_node *node;
node = of_find_node_by_type(NULL,"vdevice");
if(!node){
return -EINVAL;
}
ret = of_property_read_string(node, "vdevice-prop-3", &string);
if(ret){
return -EINVAL;
}
printk("prop-vlalue=%s\n", string);
return 0;
}

#include <linux/sys_config.h>
int get_gpio_info(void)
{
script_item_u script_val;

script_item_value_type_e type;
type = script_get_item("vdevice", "vdevice_0", &script_val);
if (SCIRPT_ITEM_VALUE_TYPE_PIO!= type) {
return -EINVAL;
}
return 0;
}

#include <linux/sys_config.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
int get_gpio_info(void)
{
unsigned int gpio;
struct gpio_config config;
struct device_node *node;
node = of_find_node_by_name(NULL,"vdevice");
if(!node){
return -EINVAL;
}
gpio = of_get_named_gpio_flags(node, "vdevice_0", 0, (enum of_gpio_flags *)&config);
if (!gpio_is_valid(gpio)) {
return -EINVAL;
}
printk("pin=%d mul-sel=%d drive=%d pull=%d data=%d gpio=%d\n",
config.gpio,
config.mul_sel,
config.drv_level,
config.pull,
config.data,
gpio);
return 0;
}

#include <linux/sys_config.h>
int check_mainkey_exist(void)
{
int ret;
ret = script_is_main_key_exist("vdevice");
if(!ret){
return -EINVAL;
}
}

int check_mainkey_exist(void)
{
struct device_node *node_1, *node_2;
/* mode 1*/
node_1 = of_find_node_by_name(NULL,"vdevice");
if(!node_1){
printk("can not find node in dts\n");
return -EINVAL;
}
/*mode 2 */
node_2 = of_find_node_by_type(NULL,"vdevice");
If(!node_2){
return -EINVAL;
}
return 0;
}

uart0: uart@01c28000 {
compatible = "allwinner,sun50i-uart";
reg = <0x0 0x01c28000 0x0 0x400>;
};
prcm {
compatible = "allwinner,prcm";
reg = <0x0 0x01f01400 0x0 0x400>;
};

soc: soc@01c00000 {
compatible = "simple-bus";
......
};
usbc0:usbc0@0 {
compatible = "allwinner,sunxi-otg-manager";
......
};

arm64_device_init()
->of_platform_populate()
->of_platform_bus_create()
->of_platform_device_create_pdata()
->of_device_alloc()
->of_device_make_bus_id()
of_device_make_bus_id()
{
......
reg = of_get_property(node, "reg", NULL);
if (reg) {
......
dev_set_name(dev, "%llx.%s", (unsigned long long)addr, node->name);
return;
}
magic = atomic_add_return(1, &bus_no_reg_magic);
dev_set_name(dev, "%s.%d", node->name, magic - 1);
}

Device Drivers-->
Device Tree and Open Firmware support-->
Suppot for device tree in /proc

out/<方案名字>/compile_dir/target/linux-<方案名字>/<内核版本>/arch/arm/boot/dts

(R6平台)
1.sun3iw1p1-sitar-soc.dtb
2.sun3iw1p1-sitar-pd4.dtb
3.sun3iw1p1-sitar-mic.dtb
3.sun3iiw1p1-sitar-cuckoo.dtb

./lichee/linux-3.10/scripts/dtc/dtc -I dtb -O dts -o output_sunxi.dts \
./out/sitar -{board} /compile_dir/target/linux-sitar –{board} /linux-3.10.65+/arch/arm/boot
/dts /sun3iw1p1-soc.dtb

./lichee/linux-3.10/scripts/dtc/dtc -I dtb -O dts -o output.dts ./out/sitar-${board} /image
/sunxi.dtb

out/方案/image/.sunxi.dtb

fdt --help

fdt - flattened device tree utility commands
Usage:
fdt addr [-c] <addr> [<length>] - Set the [control] fdt location to <addr>
fdt move <fdt> <newaddr> <length> - Copy the fdt to <addr> and make it active
fdt resize - Resize fdt to size + padding to 4k addr
fdt print <path> [<prop>] - Recursive print starting at <path>
fdt list <path> [<prop>] - Print one level starting at <path>
fdt get value <var> <path> <prop> - Get <property> and store in <var>
fdt get name <var> <path> <index> - Get name of node <index> and store in <var>
fdt get addr <var> <path> <prop> - Get start address of <property> and store in <var>
fdt get size <var> <path> [<prop>] - Get size of [<property>] or num nodes and store in <
var>
fdt set <path> <prop> [<val>] - Set <property> [to <val>]
fdt mknode <path> <node> - Create a new node after <path>
fdt rm <path> [<prop>] - Delete the node or <property>
fdt header - Display header info
fdt bootcpu <id> - Set boot cpuid
fdt memory <addr> <size> - Add/Update memory node
fdt rsvmem print - Show current mem reserves
fdt rsvmem add <addr> <size> - Add a mem reserve
fdt rsvmem delete <index> - Delete a mem reserves
fdt chosen [<start> <end>] - Add/update the /chosen branch in the tree
<start>/<end> - initrd start/end addr
fdt save - write fdt to flash

fdt print --打印整棵设备树。
fdt printf /soc/vdevice --打印“/soc/vdevice”路径下的配置信息。
fdt set /soc/vdevice status "disabled" --设置“/soc/vdevice”下status属性的属性值。
fdt save --fdt set之后需要执行fdt save才能真正写入flash保存。

说明
注：该文件节点下配置信息只能读不能写。