add 06_Pinctrl/07,08,09_编写虚拟的Pinctrl驱动程序

IMX6ULL/doc_pic/06_Pinctrl/07_编写虚拟的Pinctrl驱动程序.md

@@ -0,0 +1,147 @@
+## 编写虚拟的Pinctrl驱动程序
+
+参考资料：
+* Linux 5.x内核
+  * Documentation\devicetree\bindings\pinctrl\pinctrl-bindings.txt
+  * arch/arm/boot/dts/stm32mp151.dtsi
+  * arch/arm/boot/dts/stm32mp157-100ask-pinctrl.dtsi  
+  * arch/arm/boot/dts/stm32mp15xx-100ask.dtsi
+  * drivers\pinctrl\stm32\pinctrl-stm32mp157.c
+  * drivers\pinctrl\stm32\pinctrl-stm32.c
+
+* Linux 4.x内核
+  * Documentation\pinctrl.txt
+  * Documentation\devicetree\bindings\pinctrl\pinctrl-bindings.txt
+  * arch/arm/boot/dts/imx6ull-14x14-evk.dts
+  * arch/arm/boot/dts/100ask_imx6ull-14x14.dts
+  * drivers\pinctrl\freescale\pinctrl-imx6ul.c
+  * drivers\pinctrl\freescale\pinctrl-imx.c
+  
+* 本课对应的源码
+
+  * GIT仓库中(未测试，下一课才测试)
+
+    ```shell
+    doc_and_source_for_drivers\IMX6ULL\source\06_Pinctrl\01_virtual_pinctrl
+    doc_and_source_for_drivers\STM32MP157\source\A7\06_Pinctrl\01_virtual_pinctrl
+    ```
+
+    
+
+### 1. 回顾Pinctrl的三大作用
+
+记住pinctrl的三大作用，有助于理解所涉及的数据结构：
+
+* 引脚枚举与命名(Enumerating and naming)
+  * 单个引脚
+  * 各组引脚
+* 引脚复用(Multiplexing)：比如用作GPIO、I2C或其他功能
+* 引脚配置(Configuration)：比如上拉、下拉、open drain、驱动强度等
+
+
+
+Pinctrl驱动程序的核心是构造一个pinctrl_desc结构体：
+
+![image-20210505153958014](pic/06_Pinctrl/16_pinctrl_desc_and_pinctrl_dev.png)
+
+#### 1.1 作用1：描述、获得引脚
+
+分为2部分：
+
+* 描述、获得单个引脚的信息
+* 描述、获得某组引脚的信息
+
+![image-20210513162517514](pic/06_Pinctrl/22_pinctrl_driver_1_pin_and_group.png)
+
+#### 1.2 作用2：引脚复用
+
+用来把某组引脚(group)复用为某个功能(function)。
+
+![image-20210513162922762](pic/06_Pinctrl/23_pinctrl_driver_2_pinmux.png)
+
+#### 1.3 作用3：引脚配置
+
+用来配置：某个引脚(pin)或某组引脚(group)。
+
+![image-20210513163832306](pic/06_Pinctrl/24_pinctrl_driver_3_pinconf.png)
+
+### 2. 编写Pinctrl驱动程序要做什么
+
+![](pic/06_Pinctrl/12_pinctrl_dts_modules.png)
+
+我们要做的事情：
+
+* pin controller：
+  * 创建设备树节点
+  * 编写驱动程序
+* 测试：
+  * 创建client设备树节点
+  * 编写驱动程序
+
+
+
+### 3. 硬件功能
+
+假设这个虚拟的pin controller有4个引脚：
+
+![image-20210514094204590](pic/06_Pinctrl/25_virtual_pincontroller_hardware.png)
+
+* pin0,1,2,3都可以配置为GPIO功能
+* pin0,1还可以配置为I2C功能
+* pin2,3还可以配置为UART功能
+
+
+
+### 4. 编写设备树文件
+
+```shell
+virtual_pincontroller {
+	compatible = "100ask,virtual_pinctrl";
+	i2cgrp {
+			functions = "i2c", "i2c";
+			groups = "pin0", "pin1";
+			configs = <0x11223344  0x55667788>;
+	};
+};
+
+virtual_i2c {
+	compatible = "100ask,virtual_i2c";
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2cgrp>;
+};
+```
+
+
+
+
+
+### 5. 编写Pinctrl驱动程序
+
+#### 5.1 核心：pinctrl_desc
+
+* 分配pinctrl_desc结构体
+* 设置pinctrl_desc结构体
+* 注册pinctrl_desc结构体
+
+
+
+#### 5.2 辅助函数
+
+```c
+include/linux/of.h
+    for_each_child_of_node
+    of_get_child_count
+    of_find_property
+    of_property_read_u32
+    of_property_read_u32_index
+    of_property_read_string_index
+```
+
+
+
+
+
+### 6. 编写测试用的client驱动
+
+编写、注册一个platform_driver即可。
+

IMX6ULL/source/06_Pinctrl/01_virtual_pinctrl/virtual_pinctrl_client.c

@@ -0,0 +1,66 @@
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+static const struct of_device_id virtual_client_of_match[] = {
+	{ .compatible = "100ask,virtual_i2c", },
+	{ },
+};
+
+static int virtual_client_probe(struct platform_device *pdev)
+{
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+static int virtual_client_remove(struct platform_device *pdev)
+{
+
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+
+static struct platform_driver virtual_client_driver = {
+	.probe		= virtual_client_probe,
+	.remove		= virtual_client_remove,
+	.driver		= {
+		.name	= "100ask_virtual_client",
+		.of_match_table = of_match_ptr(virtual_client_of_match),
+	}
+};
+
+
+/* 1. 入口函数 */
+static int __init virtual_client_init(void)
+{	
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 1.1 注册一个platform_driver */
+	return platform_driver_register(&virtual_client_driver);
+}
+
+
+/* 2. 出口函数 */
+static void __exit virtual_client_exit(void)
+{
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 2.1 反注册platform_driver */
+	platform_driver_unregister(&virtual_client_driver);
+}
+
+module_init(virtual_client_init);
+module_exit(virtual_client_exit);
+
+MODULE_LICENSE("GPL");
+
+
+

IMX6ULL/source/06_Pinctrl/01_virtual_pinctrl/virtual_pinctrl_driver.c

@@ -0,0 +1,309 @@
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+static struct pinctrl_dev *g_pinctrl_dev;
+
+static const struct pinctrl_pin_desc pins[] = {
+	{0, "pin0", NULL},
+	{1, "pin1", NULL},
+	{2, "pin2", NULL},
+	{3, "pin3", NULL},
+};
+
+static unsigned long g_configs[4];
+
+struct virtual_functions_desc {
+	const char *func_name;
+	const char **groups;
+	int num_groups;
+};
+
+static struct virtual_functions_desc g_funcs_des[] = {
+	{"gpio", {"pin0", "pin1", "pin2", "pin3"}, 4},
+	{"i2c", {"pin0", "pin1"}, 2},
+	{"uart", {"pin2", "pin3"}, 2},
+};
+
+
+static const struct of_device_id virtual_pinctrl_of_match[] = {
+	{ .compatible = "100ask,virtual_pinctrl", },
+	{ },
+};
+
+static int virtual_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	return pctldev->desc->npins;
+}
+
+static const char *virtual_get_group_name(struct pinctrl_dev *pctldev,
+				       unsigned selector)
+{
+	return pctldev->desc->pins[selector].name;
+}
+
+static int virtual_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
+				  const unsigned **pins,
+				  unsigned *npins)
+{
+   if (selector >= pctldev->desc->npins)
+	   return -EINVAL;
+
+   *pins = &pctldev->desc->pins[selector].number;
+   *npins = 1;
+
+   return 0;
+}
+
+static void virtual_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
+		 unsigned offset)
+{
+  seq_printf(s, "%s", dev_name(pctldev->dev));
+}
+
+/*
+ i2cgrp {
+		 functions = "i2c", "i2c";
+		 groups = "pin0", "pin1";
+		 configs = <0x11223344	0x55667788>;
+ };
+
+ one pin ==> two pinctrl_map (one for mux, one for config)
+
+ */
+static int virtual_dt_node_to_map(struct pinctrl_dev *pctldev,
+		 struct device_node *np,
+		 struct pinctrl_map **map, unsigned *num_maps)
+{
+	int i;
+	int num_pins = 0;
+	char *pin;
+	char *function;
+	unsigned int config;
+	struct pinctrl_map *new_map;
+	unsigned long *configs;
+	
+	/* 1. 确定pin个数/分配pinctrl_map */
+	while (1)
+	{
+		if (of_property_read_string_index(np, "groups", num_pins, &pin) == 0)
+			num_pins++;
+		else
+			break;
+	}
+
+	new_map = kmalloc(sizeof(struct pinctrl_map) * num_pins * 2, GFP_KERNEL);
+	
+
+	for (i = 0; i < num_pins; i++)
+	{
+		/* 2. get pin/function/config */
+		of_property_read_string_index(np, "groups", i, &pin);
+		of_property_read_string_index(np, "functions", i, &function);
+		of_property_read_u32_index(np, "configs", i, &config);
+		
+
+		/* 3. 存入pinctrl_map   */
+		configs = kmalloc(sizeof(*configs), GFP_KERNEL);
+
+		new_map[i*2].type = PIN_MAP_TYPE_MUX_GROUP;
+		new_map[i*2].data.mux.function = function;
+		new_map[i*2].data.mux.group = pin;
+
+		new_map[i*2+1].type = PIN_MAP_TYPE_CONFIGS_PIN;
+ 		new_map[i*2+1].data.configs.group_or_pin = pin;
+ 		new_map[i*2+1].data.configs.configs = configs;
+		configs[0] = config;
+		new_map[i*2+1].data.configs.num_configs = 1;
+
+	}
+
+	*map = new_map;
+	*num_maps = num_pins * 2;
+
+	return 0;
+}
+static void virtual_dt_free_map(struct pinctrl_dev *pctldev,
+			 struct pinctrl_map *map, unsigned num_maps)
+{
+	while (num_maps--)
+	{
+		if (map->type = PIN_MAP_TYPE_CONFIGS_PIN)
+			kfree(map->data.configs.configs);
+
+		 kfree(map);
+		 map++;
+	}
+}
+
+static const struct pinctrl_ops virtual_pctrl_ops = {
+	.get_groups_count = virtual_get_groups_count,
+	.get_group_name = virtual_get_group_name,
+	.get_group_pins = virtual_get_group_pins,
+	.pin_dbg_show = virtual_pin_dbg_show,
+	.dt_node_to_map = virtual_dt_node_to_map,
+	.dt_free_map = virtual_dt_free_map,
+
+};
+
+static int virtual_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
+{
+	return ARRAY_SIZE(g_funcs_des);
+}
+
+static const char *virtual_pmx_get_func_name(struct pinctrl_dev *pctldev,
+					  unsigned selector)
+{
+	return g_funcs_des[selector].func_name;
+}
+
+static int virtual_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
+				 const char * const **groups,
+				 unsigned * const num_groups)
+{
+  *groups = g_funcs_des[selector].groups;
+  *num_groups = g_funcs_des[selector].num_groups;
+
+  return 0;
+}
+
+static int virtual_pmx_set(struct pinctrl_dev *pctldev, unsigned selector,
+			unsigned group)
+{
+	printk("set %s as %s\n", pctldev->desc->pins[group].name, g_funcs_des[selector].func_name);
+	return 0;
+}
+
+static const struct pinmux_ops virtual_pmx_ops = {
+	.get_functions_count = virtual_pmx_get_funcs_count,
+	.get_function_name = virtual_pmx_get_func_name,
+	.get_function_groups = virtual_pmx_get_groups,
+	.set_mux = virtual_pmx_set,
+};
+
+
+static int virtual_pinconf_get(struct pinctrl_dev *pctldev,
+			     unsigned pin_id, unsigned long *config)
+{
+	*config = g_configs[pin_id];
+	return 0;
+}
+
+
+static int virtual_pinconf_set(struct pinctrl_dev *pctldev,
+			  unsigned pin_id, unsigned long *configs,
+			  unsigned num_configs)
+{
+	if (num_configs != 1)
+		return -EINVAL;
+	
+	g_configs[pin_id] = *configs;
+	
+	printk("config %s as 0x%lx\n", pctldev->desc->pins[pin_id].name, *configs);
+	
+	return 0;
+}
+
+static void virtual_pinconf_dbg_show(struct pinctrl_dev *pctldev,
+				 struct seq_file *s, unsigned pin_id)
+{
+	  seq_printf(s, "0x%lx", g_configs[pin_id]);
+}
+
+static void virtual_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+			  struct seq_file *s, unsigned pin_id)
+{
+   seq_printf(s, "0x%lx", g_configs[pin_id]);
+}
+
+
+static const struct pinconf_ops virtual_pinconf_ops = {
+	.pin_config_get = virtual_pinconf_get,
+	.pin_config_set = virtual_pinconf_set,
+	.pin_config_dbg_show = virtual_pinconf_dbg_show,
+	.pin_config_group_dbg_show = virtual_pinconf_group_dbg_show,
+};
+
+
+
+static int virtual_pinctrl_probe(struct platform_device *pdev)
+{
+	struct pinctrl_desc *pictrl;
+	
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+	/* a. 分配pinctrl_desc */
+	pictrl = devm_kzalloc(&pdev->dev, sizeof(*pictrl), GFP_KERNEL);
+	
+	/* b. 设置pinctrl_desc */
+	pictrl->name = dev_name(&pdev->dev);
+	pictrl->owner = THIS_MODULE;
+	
+	/* b.1 pins and group */
+	pictrl->pins = pins;
+	pictrl->npins = ARRAY_SIZE(pins);
+
+	pictrl->pctlops = &virtual_pctrl_ops;
+	
+	/* b.2 pin mux */
+	pictrl->pmxops = &virtual_pmx_ops;
+	
+	/* b.3 pin config */
+	pictrl->confops = &virtual_pinconf_ops;
+	
+	/* c. 注册pinctrl_desc */
+	g_pinctrl_dev = devm_pinctrl_register(&pdev->dev, pictrl, NULL);
+	
+	return 0;
+}
+static int virtual_pinctrl_remove(struct platform_device *pdev)
+{
+
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+
+static struct platform_driver virtual_pinctrl_driver = {
+	.probe		= virtual_pinctrl_probe,
+	.remove		= virtual_pinctrl_remove,
+	.driver		= {
+		.name	= "100ask_virtual_pinctrl",
+		.of_match_table = of_match_ptr(virtual_pinctrl_of_match),
+	}
+};
+
+
+/* 1. 入口函数 */
+static int __init virtual_pinctrl_init(void)
+{	
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 1.1 注册一个platform_driver */
+	return platform_driver_register(&virtual_pinctrl_driver);
+}
+
+
+/* 2. 出口函数 */
+static void __exit virtual_pinctrl_exit(void)
+{
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 2.1 反注册platform_driver */
+	platform_driver_unregister(&virtual_pinctrl_driver);
+}
+
+module_init(virtual_pinctrl_init);
+module_exit(virtual_pinctrl_exit);
+
+MODULE_LICENSE("GPL");
+
+

README.md

@@ -202,6 +202,13 @@ git clone https://e.coding.net/weidongshan/linux/doc_and_source_for_drivers.git
   06_client端使用pinctrl过程的情景分析_基于IMX6ULL
   06_client端使用pinctrl过程的情景分析_基于STM32MP157
   ```
+* 2021.05.14 发布"Pinctrl子系统"：
+  
+  ```shell
+  07_编写虚拟的Pinctrl驱动程序之实现框架
+  08_编写虚拟的Pinctrl驱动程序之设置pinctrl_desc
+  09_编写虚拟的Pinctrl驱动程序之处理设备树
+  ```
   
   
   

STM32MP157/doc_pic/06_Pinctrl/07_编写虚拟的Pinctrl驱动程序.md

@@ -0,0 +1,147 @@
+## 编写虚拟的Pinctrl驱动程序
+
+参考资料：
+* Linux 5.x内核
+  * Documentation\devicetree\bindings\pinctrl\pinctrl-bindings.txt
+  * arch/arm/boot/dts/stm32mp151.dtsi
+  * arch/arm/boot/dts/stm32mp157-100ask-pinctrl.dtsi  
+  * arch/arm/boot/dts/stm32mp15xx-100ask.dtsi
+  * drivers\pinctrl\stm32\pinctrl-stm32mp157.c
+  * drivers\pinctrl\stm32\pinctrl-stm32.c
+
+* Linux 4.x内核
+  * Documentation\pinctrl.txt
+  * Documentation\devicetree\bindings\pinctrl\pinctrl-bindings.txt
+  * arch/arm/boot/dts/imx6ull-14x14-evk.dts
+  * arch/arm/boot/dts/100ask_imx6ull-14x14.dts
+  * drivers\pinctrl\freescale\pinctrl-imx6ul.c
+  * drivers\pinctrl\freescale\pinctrl-imx.c
+  
+* 本课对应的源码
+
+  * GIT仓库中(未测试，下一课才测试)
+
+    ```shell
+    doc_and_source_for_drivers\IMX6ULL\source\06_Pinctrl\01_virtual_pinctrl
+    doc_and_source_for_drivers\STM32MP157\source\A7\06_Pinctrl\01_virtual_pinctrl
+    ```
+
+    
+
+### 1. 回顾Pinctrl的三大作用
+
+记住pinctrl的三大作用，有助于理解所涉及的数据结构：
+
+* 引脚枚举与命名(Enumerating and naming)
+  * 单个引脚
+  * 各组引脚
+* 引脚复用(Multiplexing)：比如用作GPIO、I2C或其他功能
+* 引脚配置(Configuration)：比如上拉、下拉、open drain、驱动强度等
+
+
+
+Pinctrl驱动程序的核心是构造一个pinctrl_desc结构体：
+
+![image-20210505153958014](pic/06_Pinctrl/16_pinctrl_desc_and_pinctrl_dev.png)
+
+#### 1.1 作用1：描述、获得引脚
+
+分为2部分：
+
+* 描述、获得单个引脚的信息
+* 描述、获得某组引脚的信息
+
+![image-20210513162517514](pic/06_Pinctrl/22_pinctrl_driver_1_pin_and_group.png)
+
+#### 1.2 作用2：引脚复用
+
+用来把某组引脚(group)复用为某个功能(function)。
+
+![image-20210513162922762](pic/06_Pinctrl/23_pinctrl_driver_2_pinmux.png)
+
+#### 1.3 作用3：引脚配置
+
+用来配置：某个引脚(pin)或某组引脚(group)。
+
+![image-20210513163832306](pic/06_Pinctrl/24_pinctrl_driver_3_pinconf.png)
+
+### 2. 编写Pinctrl驱动程序要做什么
+
+![](pic/06_Pinctrl/12_pinctrl_dts_modules.png)
+
+我们要做的事情：
+
+* pin controller：
+  * 创建设备树节点
+  * 编写驱动程序
+* 测试：
+  * 创建client设备树节点
+  * 编写驱动程序
+
+
+
+### 3. 硬件功能
+
+假设这个虚拟的pin controller有4个引脚：
+
+![image-20210514094204590](pic/06_Pinctrl/25_virtual_pincontroller_hardware.png)
+
+* pin0,1,2,3都可以配置为GPIO功能
+* pin0,1还可以配置为I2C功能
+* pin2,3还可以配置为UART功能
+
+
+
+### 4. 编写设备树文件
+
+```shell
+virtual_pincontroller {
+	compatible = "100ask,virtual_pinctrl";
+	i2cgrp {
+			functions = "i2c", "i2c";
+			groups = "pin0", "pin1";
+			configs = <0x11223344  0x55667788>;
+	};
+};
+
+virtual_i2c {
+	compatible = "100ask,virtual_i2c";
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2cgrp>;
+};
+```
+
+
+
+
+
+### 5. 编写Pinctrl驱动程序
+
+#### 5.1 核心：pinctrl_desc
+
+* 分配pinctrl_desc结构体
+* 设置pinctrl_desc结构体
+* 注册pinctrl_desc结构体
+
+
+
+#### 5.2 辅助函数
+
+```c
+include/linux/of.h
+    for_each_child_of_node
+    of_get_child_count
+    of_find_property
+    of_property_read_u32
+    of_property_read_u32_index
+    of_property_read_string_index
+```
+
+
+
+
+
+### 6. 编写测试用的client驱动
+
+编写、注册一个platform_driver即可。
+

STM32MP157/source/A7/06_Pinctrl/01_virtual_pinctrl/virtual_pinctrl_client.c

@@ -0,0 +1,66 @@
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+static const struct of_device_id virtual_client_of_match[] = {
+	{ .compatible = "100ask,virtual_i2c", },
+	{ },
+};
+
+static int virtual_client_probe(struct platform_device *pdev)
+{
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+static int virtual_client_remove(struct platform_device *pdev)
+{
+
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+
+static struct platform_driver virtual_client_driver = {
+	.probe		= virtual_client_probe,
+	.remove		= virtual_client_remove,
+	.driver		= {
+		.name	= "100ask_virtual_client",
+		.of_match_table = of_match_ptr(virtual_client_of_match),
+	}
+};
+
+
+/* 1. 入口函数 */
+static int __init virtual_client_init(void)
+{	
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 1.1 注册一个platform_driver */
+	return platform_driver_register(&virtual_client_driver);
+}
+
+
+/* 2. 出口函数 */
+static void __exit virtual_client_exit(void)
+{
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 2.1 反注册platform_driver */
+	platform_driver_unregister(&virtual_client_driver);
+}
+
+module_init(virtual_client_init);
+module_exit(virtual_client_exit);
+
+MODULE_LICENSE("GPL");
+
+
+

STM32MP157/source/A7/06_Pinctrl/01_virtual_pinctrl/virtual_pinctrl_driver.c

@@ -0,0 +1,309 @@
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+static struct pinctrl_dev *g_pinctrl_dev;
+
+static const struct pinctrl_pin_desc pins[] = {
+	{0, "pin0", NULL},
+	{1, "pin1", NULL},
+	{2, "pin2", NULL},
+	{3, "pin3", NULL},
+};
+
+static unsigned long g_configs[4];
+
+struct virtual_functions_desc {
+	const char *func_name;
+	const char **groups;
+	int num_groups;
+};
+
+static struct virtual_functions_desc g_funcs_des[] = {
+	{"gpio", {"pin0", "pin1", "pin2", "pin3"}, 4},
+	{"i2c", {"pin0", "pin1"}, 2},
+	{"uart", {"pin2", "pin3"}, 2},
+};
+
+
+static const struct of_device_id virtual_pinctrl_of_match[] = {
+	{ .compatible = "100ask,virtual_pinctrl", },
+	{ },
+};
+
+static int virtual_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	return pctldev->desc->npins;
+}
+
+static const char *virtual_get_group_name(struct pinctrl_dev *pctldev,
+				       unsigned selector)
+{
+	return pctldev->desc->pins[selector].name;
+}
+
+static int virtual_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
+				  const unsigned **pins,
+				  unsigned *npins)
+{
+   if (selector >= pctldev->desc->npins)
+	   return -EINVAL;
+
+   *pins = &pctldev->desc->pins[selector].number;
+   *npins = 1;
+
+   return 0;
+}
+
+static void virtual_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
+		 unsigned offset)
+{
+  seq_printf(s, "%s", dev_name(pctldev->dev));
+}
+
+/*
+ i2cgrp {
+		 functions = "i2c", "i2c";
+		 groups = "pin0", "pin1";
+		 configs = <0x11223344	0x55667788>;
+ };
+
+ one pin ==> two pinctrl_map (one for mux, one for config)
+
+ */
+static int virtual_dt_node_to_map(struct pinctrl_dev *pctldev,
+		 struct device_node *np,
+		 struct pinctrl_map **map, unsigned *num_maps)
+{
+	int i;
+	int num_pins = 0;
+	char *pin;
+	char *function;
+	unsigned int config;
+	struct pinctrl_map *new_map;
+	unsigned long *configs;
+	
+	/* 1. 确定pin个数/分配pinctrl_map */
+	while (1)
+	{
+		if (of_property_read_string_index(np, "groups", num_pins, &pin) == 0)
+			num_pins++;
+		else
+			break;
+	}
+
+	new_map = kmalloc(sizeof(struct pinctrl_map) * num_pins * 2, GFP_KERNEL);
+	
+
+	for (i = 0; i < num_pins; i++)
+	{
+		/* 2. get pin/function/config */
+		of_property_read_string_index(np, "groups", i, &pin);
+		of_property_read_string_index(np, "functions", i, &function);
+		of_property_read_u32_index(np, "configs", i, &config);
+		
+
+		/* 3. 存入pinctrl_map   */
+		configs = kmalloc(sizeof(*configs), GFP_KERNEL);
+
+		new_map[i*2].type = PIN_MAP_TYPE_MUX_GROUP;
+		new_map[i*2].data.mux.function = function;
+		new_map[i*2].data.mux.group = pin;
+
+		new_map[i*2+1].type = PIN_MAP_TYPE_CONFIGS_PIN;
+ 		new_map[i*2+1].data.configs.group_or_pin = pin;
+ 		new_map[i*2+1].data.configs.configs = configs;
+		configs[0] = config;
+		new_map[i*2+1].data.configs.num_configs = 1;
+
+	}
+
+	*map = new_map;
+	*num_maps = num_pins * 2;
+
+	return 0;
+}
+static void virtual_dt_free_map(struct pinctrl_dev *pctldev,
+			 struct pinctrl_map *map, unsigned num_maps)
+{
+	while (num_maps--)
+	{
+		if (map->type = PIN_MAP_TYPE_CONFIGS_PIN)
+			kfree(map->data.configs.configs);
+
+		 kfree(map);
+		 map++;
+	}
+}
+
+static const struct pinctrl_ops virtual_pctrl_ops = {
+	.get_groups_count = virtual_get_groups_count,
+	.get_group_name = virtual_get_group_name,
+	.get_group_pins = virtual_get_group_pins,
+	.pin_dbg_show = virtual_pin_dbg_show,
+	.dt_node_to_map = virtual_dt_node_to_map,
+	.dt_free_map = virtual_dt_free_map,
+
+};
+
+static int virtual_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
+{
+	return ARRAY_SIZE(g_funcs_des);
+}
+
+static const char *virtual_pmx_get_func_name(struct pinctrl_dev *pctldev,
+					  unsigned selector)
+{
+	return g_funcs_des[selector].func_name;
+}
+
+static int virtual_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
+				 const char * const **groups,
+				 unsigned * const num_groups)
+{
+  *groups = g_funcs_des[selector].groups;
+  *num_groups = g_funcs_des[selector].num_groups;
+
+  return 0;
+}
+
+static int virtual_pmx_set(struct pinctrl_dev *pctldev, unsigned selector,
+			unsigned group)
+{
+	printk("set %s as %s\n", pctldev->desc->pins[group].name, g_funcs_des[selector].func_name);
+	return 0;
+}
+
+static const struct pinmux_ops virtual_pmx_ops = {
+	.get_functions_count = virtual_pmx_get_funcs_count,
+	.get_function_name = virtual_pmx_get_func_name,
+	.get_function_groups = virtual_pmx_get_groups,
+	.set_mux = virtual_pmx_set,
+};
+
+
+static int virtual_pinconf_get(struct pinctrl_dev *pctldev,
+			     unsigned pin_id, unsigned long *config)
+{
+	*config = g_configs[pin_id];
+	return 0;
+}
+
+
+static int virtual_pinconf_set(struct pinctrl_dev *pctldev,
+			  unsigned pin_id, unsigned long *configs,
+			  unsigned num_configs)
+{
+	if (num_configs != 1)
+		return -EINVAL;
+	
+	g_configs[pin_id] = *configs;
+	
+	printk("config %s as 0x%lx\n", pctldev->desc->pins[pin_id].name, *configs);
+	
+	return 0;
+}
+
+static void virtual_pinconf_dbg_show(struct pinctrl_dev *pctldev,
+				 struct seq_file *s, unsigned pin_id)
+{
+	  seq_printf(s, "0x%lx", g_configs[pin_id]);
+}
+
+static void virtual_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+			  struct seq_file *s, unsigned pin_id)
+{
+   seq_printf(s, "0x%lx", g_configs[pin_id]);
+}
+
+
+static const struct pinconf_ops virtual_pinconf_ops = {
+	.pin_config_get = virtual_pinconf_get,
+	.pin_config_set = virtual_pinconf_set,
+	.pin_config_dbg_show = virtual_pinconf_dbg_show,
+	.pin_config_group_dbg_show = virtual_pinconf_group_dbg_show,
+};
+
+
+
+static int virtual_pinctrl_probe(struct platform_device *pdev)
+{
+	struct pinctrl_desc *pictrl;
+	
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+
+	/* a. 分配pinctrl_desc */
+	pictrl = devm_kzalloc(&pdev->dev, sizeof(*pictrl), GFP_KERNEL);
+	
+	/* b. 设置pinctrl_desc */
+	pictrl->name = dev_name(&pdev->dev);
+	pictrl->owner = THIS_MODULE;
+	
+	/* b.1 pins and group */
+	pictrl->pins = pins;
+	pictrl->npins = ARRAY_SIZE(pins);
+
+	pictrl->pctlops = &virtual_pctrl_ops;
+	
+	/* b.2 pin mux */
+	pictrl->pmxops = &virtual_pmx_ops;
+	
+	/* b.3 pin config */
+	pictrl->confops = &virtual_pinconf_ops;
+	
+	/* c. 注册pinctrl_desc */
+	g_pinctrl_dev = devm_pinctrl_register(&pdev->dev, pictrl, NULL);
+	
+	return 0;
+}
+static int virtual_pinctrl_remove(struct platform_device *pdev)
+{
+
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	return 0;
+}
+
+
+static struct platform_driver virtual_pinctrl_driver = {
+	.probe		= virtual_pinctrl_probe,
+	.remove		= virtual_pinctrl_remove,
+	.driver		= {
+		.name	= "100ask_virtual_pinctrl",
+		.of_match_table = of_match_ptr(virtual_pinctrl_of_match),
+	}
+};
+
+
+/* 1. 入口函数 */
+static int __init virtual_pinctrl_init(void)
+{	
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 1.1 注册一个platform_driver */
+	return platform_driver_register(&virtual_pinctrl_driver);
+}
+
+
+/* 2. 出口函数 */
+static void __exit virtual_pinctrl_exit(void)
+{
+	printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
+	/* 2.1 反注册platform_driver */
+	platform_driver_unregister(&virtual_pinctrl_driver);
+}
+
+module_init(virtual_pinctrl_init);
+module_exit(virtual_pinctrl_exit);
+
+MODULE_LICENSE("GPL");
+
+