updated expander driver to allow working with gpio expander

linux_kernel_modules/expander/expander.c

@@ -16,19 +16,18 @@
 #define TRI_LED_BLU		(7)
 #define TRI_LED_GRN		(15)
 #define TRI_LED_RED		(10)
-#define BUZZER			(0)
 
 
 struct expander_device {
 	struct platform_device *pdev;
-	atomic_t generic_led_val, pcm_sel_val, sdio_sel_val, buzzer_val,
+	atomic_t generic_led_val, pcm_sel_val, sdio_sel_val,
 	         tri_led_blu_val, tri_led_red_val, tri_led_grn_val;
 	int gpio_expander_base;
 };
 
 
 
-#define CREATE_SYSFS_DEFN(_var, _offset)                                       \
+#define CREATE_SYSFS_DEFN(_var, _offset,_valchange)                            \
 static ssize_t _var##_show(struct device *dev,  struct device_attribute *attr, \
                            char *buf)                                          \
 {                                                                              \
@@ -45,7 +44,8 @@ static int _var##_store(struct device *dev, struct device_attribute *attr,     \
         ret = kstrtou8(buf, 10, &val);                                         \
         if (ret || val > 1)                                                    \
                 return -EINVAL;                                                \
-                                                                               \
+        if (_valchange)                                                        \
+        { val = !val;}                                                         \
         gpio_set_value_cansleep(exp->gpio_expander_base + _offset, val);       \
         atomic_set(&exp->_var##_val, val);                                     \
         dev_info(dev, "Setting GPIO %d to %d\n",                               \
@@ -55,26 +55,26 @@ static int _var##_store(struct device *dev, struct device_attribute *attr,     \
 }                                                                              \
 static DEVICE_ATTR_RW(_var)
 
-CREATE_SYSFS_DEFN(generic_led, GENERIC_LED);
-CREATE_SYSFS_DEFN(pcm_sel, PCM_SEL);
-CREATE_SYSFS_DEFN(sdio_sel, SDIO_SEL);
-CREATE_SYSFS_DEFN(tri_led_blu, TRI_LED_BLU);
-CREATE_SYSFS_DEFN(tri_led_red, TRI_LED_RED);
-CREATE_SYSFS_DEFN(tri_led_grn, TRI_LED_GRN);
-CREATE_SYSFS_DEFN(buzzer, BUZZER);
-
+CREATE_SYSFS_DEFN(generic_led, GENERIC_LED,false);
+CREATE_SYSFS_DEFN(pcm_sel, PCM_SEL,false);
+CREATE_SYSFS_DEFN(sdio_sel, SDIO_SEL,false);
+CREATE_SYSFS_DEFN(tri_led_blu, TRI_LED_BLU,true);
+CREATE_SYSFS_DEFN(tri_led_red, TRI_LED_RED,true);
+CREATE_SYSFS_DEFN(tri_led_grn, TRI_LED_GRN,true);
 
 static int gpio_initial_status(struct platform_device *pdev,
 			       struct device_attribute *attr,
 			       int expander_gpio_offset, int gpio_output_level,
-			       atomic_t *atomic_val)
+			       atomic_t *atomic_val, bool is_open_drain,
+                               bool is_active_low)
 {
 	struct expander_device *exp = dev_get_drvdata(&pdev->dev);
  	const int gpio_num = exp->gpio_expander_base + expander_gpio_offset;
 	int ret = devm_gpio_request_one(
 		&pdev->dev, gpio_num,
 		(GPIOF_DIR_OUT |
-		 (gpio_output_level ? GPIOF_INIT_HIGH : GPIOF_INIT_LOW)),
+		(gpio_output_level ? GPIOF_INIT_HIGH : GPIOF_INIT_LOW) |
+                (is_open_drain ? GPIOF_OPEN_DRAIN : 0)),
 		attr->attr.name);
 	if (ret != 0) {
 		dev_err(&pdev->dev, "Couldn't request GPIO %d\n", gpio_num);
@@ -128,31 +128,27 @@ static int expander_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, dev);
 
 	ret = gpio_initial_status(pdev, &dev_attr_generic_led, GENERIC_LED, 0,
-			    &dev->generic_led_val);
+			    &dev->generic_led_val, false, false);
 	if (ret)
 		goto done;
 	ret = gpio_initial_status(pdev, &dev_attr_pcm_sel, PCM_SEL, 0,
-			    &dev->pcm_sel_val);
+			    &dev->pcm_sel_val, false, false);
 	if (ret)
 		goto done;
 	ret = gpio_initial_status(pdev, &dev_attr_sdio_sel, SDIO_SEL, 0,
-			    &dev->sdio_sel_val);
+			    &dev->sdio_sel_val, false, false);
 	if (ret)
 		goto done;
 	ret = gpio_initial_status(pdev, &dev_attr_tri_led_blu, TRI_LED_BLU, 0,
-			    &dev->tri_led_blu_val);
+			    &dev->tri_led_blu_val , true, true );
 	if (ret)
 		goto done;
 	ret = gpio_initial_status(pdev, &dev_attr_tri_led_red, TRI_LED_RED, 0,
-			    &dev->tri_led_red_val);
+			    &dev->tri_led_red_val , true, true);
 	if (ret)
 		goto done;
 	ret = gpio_initial_status(pdev, &dev_attr_tri_led_grn, TRI_LED_GRN, 0,
-			    &dev->tri_led_grn_val);
-	if (ret)
-		goto done;
-	ret = gpio_initial_status(pdev, &dev_attr_buzzer, BUZZER, 0,
-			    &dev->buzzer_val);
+			    &dev->tri_led_grn_val, true, true);
 	if (ret)
 		goto done;
 
@@ -169,7 +165,6 @@ static int expander_remove(struct platform_device *pdev)
 	gpio_final_status(pdev, &dev_attr_tri_led_blu, TRI_LED_BLU, 0);
 	gpio_final_status(pdev, &dev_attr_tri_led_red, TRI_LED_RED, 0);
 	gpio_final_status(pdev, &dev_attr_tri_led_grn, TRI_LED_GRN, 0);
-	gpio_final_status(pdev, &dev_attr_buzzer, BUZZER, 0);
 
 	return 0;
 }