pinctrl框架
2024-08-26 22:41:25
pinctrl框架是linux系统为统一各SOC厂家pin管理，目的是为了减少SOC厂家系统移植工作量。
通常通过设备树初始化pinctrl，并提供调用io接口，以下为全志A64平台的实例：
在drivers/pinctrl/sunxi/pinctrl-sun50iw1p1.c:
static const struct sunxi_desc_pin sun50iw1p1_pins[] = {
SUNXI_PIN(SUNXI_PINCTRL_PIN(B, ),
SUNXI_FUNCTION(0x0, "gpio_in"),
SUNXI_FUNCTION(0x1, "gpio_out"),
SUNXI_FUNCTION(0x2, "uart2"), /*TX*/
SUNXI_FUNCTION(0x3, "vdevice"), /*vdevice for test */
SUNXI_FUNCTION(0x4, "jtag0"), /*MS0*/
SUNXI_FUNCTION(0x7, "io_disabled"),
SUNXI_FUNCTION_IRQ_BANK(0x6, , )), /*PB_EINT0 */
SUNXI_PIN(SUNXI_PINCTRL_PIN(B, ),
SUNXI_FUNCTION(0x0, "gpio_in"),
SUNXI_FUNCTION(0x1, "gpio_out"),
SUNXI_FUNCTION(0x2, "uart2"), /*RX*/
SUNXI_FUNCTION(0x3, "vdevice"), /*vdevice for test */
SUNXI_FUNCTION(0x4, "jtag0"), /*CK0*/
SUNXI_FUNCTION(0x5, "sim0"), /*PWREN*/
SUNXI_FUNCTION(0x7, "io_disabled"),
SUNXI_FUNCTION_IRQ_BANK(0x6, , )), /*PB_EINT1 */
......
......
......
};
static const struct sunxi_pinctrl_desc sun50iw1p1_pinctrl_data = {
.pins = sun50iw1p1_pins,
.npins = ARRAY_SIZE(sun50iw1p1_pins),
.irq_banks = ,
};
static int sun50iw1p1_pinctrl_probe(struct platform_device *pdev)
{
pr_warn("[%s][%d]\n", __func__, __LINE__);
return sunxi_pinctrl_init(pdev,
&sun50iw1p1_pinctrl_data);
}
static struct of_device_id sun50iw1p1_pinctrl_match[] = {
{ .compatible = "allwinner,sun50i-pinctrl", },
{}
};
MODULE_DEVICE_TABLE(of, sun50iw1p1_pinctrl_match);
static struct platform_driver sun50iw1p1_pinctrl_driver = {
.probe = sun50iw1p1_pinctrl_probe,
.driver = {
.name = "sun50i-pinctrl",
.owner = THIS_MODULE,
.of_match_table = sun50iw1p1_pinctrl_match,
},
};
static int __init sun50iw1p1_pio_init(void)
{
int ret;
ret = platform_driver_register(&sun50iw1p1_pinctrl_driver);
if (IS_ERR_VALUE(ret)) {
pr_debug("register sun50i pio controller failed\n");
return -EINVAL;
}
return ;
}
postcore_initcall(sun50iw1p1_pio_init);
start_kernel----rest_init----kernel_init----kernel_init_freeable----do_basic_setup----do_initcalls调用postcore_initcall。
注册平台驱动，匹配设备最后调用sunxi_pinctrl_init(pdev, &sun50iw1p1_pinctrl_data);
sun50iw1p1_pins为全志平台的PIN IO和IRQ的定义，里面定义引脚名字name，复用功能muxval，中断号irqnum。
忽略部分代码的drivers/pinctrl/sunxi/pinctrl-sunxi.c:
int sunxi_pinctrl_init(struct platform_device *pdev,
const struct sunxi_pinctrl_desc *desc)
{
struct device_node *node = pdev->dev.of_node;
struct pinctrl_desc *pctrl_desc;
struct pinctrl_pin_desc *pins;
struct sunxi_pinctrl *pctl;
struct resource *res;
int i, ret, last_pin;
struct clk *clk;
pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL); platform_set_drvdata(pdev, pctl); res = platform_get_resource(pdev, IORESOURCE_MEM, );
pctl->membase = devm_ioremap_resource(&pdev->dev, res); //返回设备的MEM资源的虚拟地址 pctl->dev = &pdev->dev;
pctl->desc = desc; pctl->irq_array = devm_kcalloc(&pdev->dev, IRQ_PER_BANK * pctl->desc->irq_banks,
sizeof(*pctl->irq_array), GFP_KERNEL); //把sunxi_pinctrl_desc的内容全部映射到sunxi_pinctrl的成员(sunxi_pinctrl_group、irq_array和sunxi_pinctrl_function)
ret = sunxi_pinctrl_build_state(pdev); pins = devm_kzalloc(&pdev->dev, pctl->desc->npins * sizeof(*pins), GFP_KERNEL); for (i = ; i < pctl->desc->npins; i++)
pins[i] = pctl->desc->pins[i].pin; //注册pctldev，这里把平台硬件相关函数向上映射到pinctrl子系统
pctrl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctrl_desc), GFP_KERNEL); //confops、pctlops和pmxops都是直接和硬件相关，新设备配置PIN需要用到
pctrl_desc->name = dev_name(&pdev->dev);
pctrl_desc->owner = THIS_MODULE;
pctrl_desc->pins = pins;
pctrl_desc->npins = pctl->desc->npins;
pctrl_desc->confops = &sunxi_pconf_ops; //pin config operations vtable
pctrl_desc->pctlops = &sunxi_pctrl_ops; //pin control operation vtable
pctrl_desc->pmxops = &sunxi_pmx_ops; //pinmux operations vtable //把描述表的name和number加入radix_tree，分配pinctrl_dev并把加入双链表，这里没有创建新的pinctrl设备，也没有state
pctl->pctl_dev = pinctrl_register(pctrl_desc, &pdev->dev, pctl); //注册gpio子系统，把平台硬件相关函数向上映射到gpio子系统
pctl->chip = devm_kzalloc(&pdev->dev, sizeof(*pctl->chip), GFP_KERNEL); last_pin = pctl->desc->pins[pctl->desc->npins - ].pin.number;
pctl->chip->owner = THIS_MODULE;
pctl->chip->request = sunxi_pinctrl_gpio_request,
pctl->chip->free = sunxi_pinctrl_gpio_free,
pctl->chip->direction_input = sunxi_pinctrl_gpio_direction_input,
pctl->chip->direction_output = sunxi_pinctrl_gpio_direction_output,
pctl->chip->get = sunxi_pinctrl_gpio_get,
pctl->chip->set = sunxi_pinctrl_gpio_set,
pctl->chip->set_debounce = sunxi_pinctrl_gpio_set_debounce,
pctl->chip->of_xlate = sunxi_pinctrl_gpio_of_xlate,
pctl->chip->to_irq = sunxi_pinctrl_gpio_to_irq,
pctl->chip->of_gpio_n_cells = ,
pctl->chip->can_sleep = false,
pctl->chip->ngpio = round_up(last_pin + , PINS_PER_BANK) - pctl->desc->pin_base;
pctl->chip->label = dev_name(&pdev->dev);
pctl->chip->dev = &pdev->dev;
pctl->chip->base = pctl->desc->pin_base; ret = gpiochip_add(pctl->chip); //把gpio_chip(A64有两个chip)加入双链表 for (i = ; i < pctl->desc->npins; i++) {
const struct sunxi_desc_pin *pin = pctl->desc->pins + i;
//注册gpio_ranges，并加入双链表
ret = gpiochip_add_pin_range(pctl->chip, dev_name(&pdev->dev),
pin->pin.number - pctl->desc->pin_base,
pin->pin.number, );
} clk = devm_clk_get(&pdev->dev, NULL); ret = clk_prepare_enable(clk);
if (ret)
goto gpiochip_error; pctl->irq = devm_kcalloc(&pdev->dev,
pctl->desc->irq_banks,
sizeof(*pctl->irq),
GFP_KERNEL); for (i = ; i < pctl->desc->irq_banks; i++) {
pctl->irq[i] = platform_get_irq(pdev, i); //获取中断资源
} pctl->domain = irq_domain_add_linear(node, pctl->desc->irq_banks * IRQ_PER_BANK,
&irq_domain_simple_ops, NULL); //把pinctrl加入线性中断域，pin中断都域中搜索 for (i = ; i < (pctl->desc->irq_banks * IRQ_PER_BANK); i++) {
int irqno = irq_create_mapping(pctl->domain, i); //获取线性中断域的irq号 irq_set_chip_and_handler(irqno, &sunxi_pinctrl_edge_irq_chip,
handle_edge_irq); //sunxi_pinctrl_edge_irq_chip为全志底层irq_chip操作
irq_set_chip_data(irqno, pctl);
}; for (i = ; i < pctl->desc->irq_banks; i++) {
/* Mask and clear all IRQs before registering a handler */
writel(, pctl->membase + sunxi_irq_ctrl_reg_from_bank(i));
writel(0xffffffff, pctl->membase + sunxi_irq_status_reg_from_bank(i));
if(pctl->desc->pin_base >= PL_BASE){
ret = devm_request_irq(&pdev->dev, pctl->irq[i], sunxi_pinctrl_irq_handler,
IRQF_SHARED | IRQF_NO_SUSPEND, "PIN_GRP", pctl);
//同一个bank的gpio中断均共享一个中断，在sunxi_pinctrl_irq_handler通过gpio的中断号
//启动对应generic_handle_irq
}else{
ret = devm_request_irq(&pdev->dev, pctl->irq[i], sunxi_pinctrl_irq_handler,
IRQF_SHARED, "PIN_GRP", pctl); //同上
}
} return ;
}
在设备树实例（一）中的：
soc@01c00000 {
compatible = "simple-bus";
#address-cells = <0x2>;
#size-cells = <0x2>;
ranges;
device_type = "soc";
pinctrl@01c20800 {
compatible = "allwinner,sun50i-pinctrl";
reg = <0x0 0x1c20800 0x0 0x400>;
interrupts = <0x0 0xb 0x4 0x0 0x11 0x4 0x0 0x15 0x4>;
device_type = "pio";
clocks = <0xa>;
gpio-controller;
interrupt-controller;
#interrupt-cells = <0x2>;
#size-cells = <0x0>;
#gpio-cells = <0x6>;
linux,phandle = <0x30>;
phandle = <0x30>;
uart0@ {
allwinner,pins = "PB8", "PB9";
allwinner,pname = "uart0_tx", "uart0_rx";
allwinner,function = "uart0";
allwinner,muxsel = <0x4>;
allwinner,drive = <0x1>;
allwinner,pull = <0x1>;
linux,phandle = <0x19>;
phandle = <0x19>;
};
uart0@ {
allwinner,pins = "PB8", "PB9";
allwinner,function = "io_disabled";
allwinner,muxsel = <0x7>;
allwinner,drive = <0x1>;
allwinner,pull = <0x1>;
linux,phandle = <0x1a>;
phandle = <0x1a>;
};
......
......
......
};
uart@01c28000 {
compatible = "allwinner,sun50i-uart";
device_type = "uart0";
reg = <0x0 0x1c28000 0x0 0x400>;
interrupts = <0x0 0x0 0x4>;
clocks = <0x18>;
pinctrl-names = "default", "sleep";
pinctrl- = <0x19>;
pinctrl- = <0x1a>;
uart0_port = <0x0>;
uart0_type = <0x2>;
status = "disabled";
};
pinctrl-names = "default", "sleep";的两种状态的phandle对应于pinctrl-0(uart0@0)和pinctrl-1(uart0@1)，uart0@0里面的配置是全志硬件平台相关，跟confops、pctlops和pmxops相关。
如何开启设备树对应的pin配置？
一般在driver程序里面调用devm_pinctrl_get_select_default就可以。
定义在linux3-10/include/pintrl/consumer.h：
static inline struct pinctrl * __must_check devm_pinctrl_get_select(
struct device *dev, const char *name)
{
struct pinctrl *p;
struct pinctrl_state *s;
int ret; //通过device获取phandle，若是新设备则会调用创建head_list，找到pinctrl父设备sun50i-pinctrl ，解析设备树，
//创建states，获取硬件相关配置，最后add devices。
p = devm_pinctrl_get(dev);
if (IS_ERR(p))
return p; s = pinctrl_lookup_state(p, name);
if (IS_ERR(s)) {
devm_pinctrl_put(p);
return ERR_CAST(s);
}
//设置state(默认是DEFAULT)从设备树对应的配置
ret = pinctrl_select_state(p, s);
if (ret < ) {
devm_pinctrl_put(p);
return ERR_PTR(ret);
} return p;
}
调用IO口或者中断可以参考linux-3.10/drivers/pinctrl/sunxi/pinctrl-sunxi-test.c
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sys_config.h>
#include <linux/string.h> static struct of_device_id sunxi_pinctrl_test_match[] = {
{ .compatible = "allwinner,sun50i-vdevice"},
}; //这里要在dts文件建立compatible = "allwinner,sun50i-vdevice"的node才能匹配driver static irqreturn_t test_sunxi_pinctrl_irq_handler(int irq, void *dev_id)
{
pr_warn("[%s] handler for test pinctrl eint api.\n", __func__);
disable_irq_nosync(irq);
return IRQ_HANDLED; } static int sunxi_pinctrl_test_probe(struct platform_device *pdev)
{
struct gpio_config config;
unsigned int ret;
struct device_node *node; int req_irq_status;
int req_status;
int virq; node=of_find_node_by_type(NULL, "vdevice"); //通过属性device_type = "vdevice"找到设备树节点
if(!node){
printk("find node\n");
}
ret = of_get_named_gpio_flags(node, "test-gpios", , (enum of_gpio_flags *)&config);
//找到设备树属性test-gpios，解析GPIO配置，这步是重点(不同硬件平台不一定相同)
if (!gpio_is_valid(ret)) {
return -EINVAL;
}
printk("config: gpio=%d mul=%d drive=%d pull=%d data=%d\n"
, config.gpio
, config.mul_sel
, config.drv_level
, config.pull
, config.data);
req_status = gpio_request(config.gpio, NULL);
if ( != req_status)
return -EINVAL;
virq = gpio_to_irq(config.gpio);
if (IS_ERR_VALUE(virq)) {
pr_warn("gpio[%d]get virq[%d] failed!\n", config.gpio, virq);
return -EINVAL;
}
req_irq_status = devm_request_irq(&pdev->dev, virq,
test_sunxi_pinctrl_irq_handler,
IRQF_TRIGGER_LOW, "GPIO_EINT", NULL);
if (IS_ERR_VALUE(req_irq_status)) {
pr_warn("request irq failed !\n");
return -EINVAL;
}
return ;
} static struct platform_driver sunxi_pinctrl_test_driver = {
.probe = sunxi_pinctrl_test_probe,
.driver = {
.name = "vdevice",
.owner = THIS_MODULE,
.of_match_table = sunxi_pinctrl_test_match,
},
}; static int __init sunxi_pinctrl_test_init(void)
{
int ret;
ret = platform_driver_register(&sunxi_pinctrl_test_driver);
if (IS_ERR_VALUE(ret)) {
pr_warn("register sunxi pinctrl platform driver failed\n");
return -EINVAL;
}
return ;
}
late_initcall(sunxi_pinctrl_test_init); MODULE_AUTHOR("Huangshr<huangshr@allwinnertech.com");
MODULE_DESCRIPTION("Allwinner SUNXI Pinctrl driver test");
MODULE_LICENSE("GPL");
一般应用是
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