[PATCH v6 3/3] leds/powernv: Add driver for PowerNV platform
Vasant Hegde
hegdevasant at linux.vnet.ibm.com
Sat Jul 18 02:20:20 AEST 2015
On 07/17/2015 08:55 PM, Jacek Anaszewski wrote:
> Hi Vasant,
Hi Jacek,
.../...
>> As per the LED class framework, the 'brightness_set' function should not
>> sleep. Hence these functions have been implemented through global work
>> queue tasks which might sleep on OPAL async call completion.
>>
>> The platform level implementation of LED get and set state has been achieved
>
> Please don't exceed 75 character line length limit.
Ok. I will fix it.. But I thought 80 character is the limit.
>
>> through OPAL calls. These calls are made available for the driver by
>> exporting from architecture specific codes.
>>
.../...
>> +
>> +#include <asm/opal.h>
>> +
>> +/*
>> + * By default unload path resets all the LEDs. But on PowerNV platform
>> + * we want to retain LED state across reboot as these are controlled by
>> + * firmware. Also service processor can modify the LEDs independent of
>> + * OS. Hence avoid resetting LEDs in unload path.
>> + */
>> +static bool led_disabled;
>
> Please move this to the struct powernv_leds_priv.
Hmmm.. Ok. Will update and use platform_get_drvdata to access platform_get_drvdata.
>
>> +
>> +/* Map LED type to description. */
>> +struct led_type_map {
>> + const int type;
>> + const char *desc;
>> +};
>> +static const struct led_type_map led_type_map[] = {
>> + {OPAL_SLOT_LED_TYPE_ID, POWERNV_LED_TYPE_IDENTIFY},
>> + {OPAL_SLOT_LED_TYPE_FAULT, POWERNV_LED_TYPE_FAULT},
>> + {OPAL_SLOT_LED_TYPE_ATTN, POWERNV_LED_TYPE_ATTENTION},
>> + {-1, NULL},
>> +};
>> +
>> +/*
>> + * LED set routines have been implemented as work queue tasks scheduled
>> + * on the global work queue. Individual task calls OPAL interface to set
>> + * the LED state which might sleep for some time.
>> + */
>> +struct powernv_led_data {
>> + struct led_classdev cdev;
>> + char *loc_code; /* LED location code */
>> + int led_type; /* OPAL_SLOT_LED_TYPE_* */
>> + enum led_brightness value; /* Brightness value */
>> + struct mutex lock;
>> + struct work_struct work_led; /* LED update workqueue */
>> +};
>> +
>> +struct powernv_leds_priv {
>> + int num_leds;
>> + struct powernv_led_data powernv_leds[];
>> +};
>> +
>> +static __be64 max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX);
>
> The C standard prohibits initialization of global objects with non-constant
> values. Section 6.7.8 of the C99 standard states:
>
> "All the expressions in an initializer for an object that has static storage
> duration shall be constant expressions or string literals."
>
> Compilation succeeds when using powerpc64-linux-gcc because then
> the following version of macro is used:
>
> #define cpu_to_be64(x) (x)
>
> and not
>
> #define cpu_to_be64(x) swab64(x)
>
> Please move max_led_type also to the struct powernv_leds_priv
> and initialize it dynamically.
Yeah.. I should have added this to structure itself. Will fix.
>
>> +
>> +
>> +static inline int sizeof_powernv_leds_priv(int num_leds)
>> +{
>> + return sizeof(struct powernv_leds_priv) +
>> + (sizeof(struct powernv_led_data) * num_leds);
>> +}
>> +/* Returns OPAL_SLOT_LED_TYPE_* for given led type string */
>> +static int powernv_get_led_type(const char *led_type_desc)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(led_type_map); i++)
>> + if (!strcmp(led_type_map[i].desc, led_type_desc))
>> + return led_type_map[i].type;
>> +
>> + return -1;
>> +}
>> +
>> +/*
>> + * This commits the state change of the requested LED through an OPAL call.
>> + * This function is called from work queue task context when ever it gets
>> + * scheduled. This function can sleep at opal_async_wait_response call.
>> + */
>> +static void powernv_led_set(struct powernv_led_data *powernv_led)
>> +{
>> + int rc, token;
>> + u64 led_mask, led_value = 0;
>> + __be64 max_type;
>> + struct opal_msg msg;
>> + struct device *dev = powernv_led->cdev.dev;
>> +
>> + /* Prepare for the OPAL call */
>> + max_type = max_led_type;
>> + led_mask = OPAL_SLOT_LED_STATE_ON << powernv_led->led_type;
>> + if (powernv_led->value)
>> + led_value = led_mask;
>> +
>> + /* OPAL async call */
>> + token = opal_async_get_token_interruptible();
>> + if (token < 0) {
>> + if (token != -ERESTARTSYS)
>> + dev_err(dev, "%s: Couldn't get OPAL async token\n",
>> + __func__);
>> + return;
>> + }
>> +
>> + rc = opal_leds_set_ind(token, powernv_led->loc_code,
>> + led_mask, led_value, &max_type);
>> + if (rc != OPAL_ASYNC_COMPLETION) {
>> + dev_err(dev, "%s: OPAL set LED call failed for %s [rc=%d]\n",
>> + __func__, powernv_led->loc_code, rc);
>> + goto out_token;
>> + }
>> +
>> + rc = opal_async_wait_response(token, &msg);
>> + if (rc) {
>> + dev_err(dev,
>> + "%s: Failed to wait for the async response [rc=%d]\n",
>> + __func__, rc);
>> + goto out_token;
>> + }
>> +
>> + rc = be64_to_cpu(msg.params[1]);
>> + if (rc != OPAL_SUCCESS)
>> + dev_err(dev, "%s : OAPL async call returned failed [rc=%d]\n",
>> + __func__, rc);
>> +
>> +out_token:
>> + opal_async_release_token(token);
>> +}
>> +
>> +/*
>> + * This function fetches the LED state for a given LED type for
>> + * mentioned LED classdev structure.
>> + */
>> +static enum led_brightness
>> +powernv_led_get(struct powernv_led_data *powernv_led)
>> +{
>> + int rc;
>> + __be64 mask, value, max_type;
>> + u64 led_mask, led_value;
>> + struct device *dev = powernv_led->cdev.dev;
>> +
>> + /* Fetch all LED status */
>> + mask = cpu_to_be64(0);
>> + value = cpu_to_be64(0);
>> + max_type = max_led_type;
>> +
>> + rc = opal_leds_get_ind(powernv_led->loc_code,
>> + &mask, &value, &max_type);
>> + if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
>> + dev_err(dev, "%s: OPAL get led call failed [rc=%d]\n",
>> + __func__, rc);
>> + return LED_OFF;
>> + }
>> +
>> + led_mask = be64_to_cpu(mask);
>> + led_value = be64_to_cpu(value);
>> +
>> + /* LED status available */
>> + if (!((led_mask >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)) {
>> + dev_err(dev, "%s: LED status not available for %s\n",
>> + __func__, powernv_led->cdev.name);
>> + return LED_OFF;
>> + }
>> +
>> + /* LED status value */
>> + if ((led_value >> powernv_led->led_type) & OPAL_SLOT_LED_STATE_ON)
>> + return LED_FULL;
>> +
>> + return LED_OFF;
>> +}
>> +
>> +/* Execute LED set task for given led classdev */
>> +static void powernv_deferred_led_set(struct work_struct *work)
>> +{
>> + struct powernv_led_data *powernv_led =
>> + container_of(work, struct powernv_led_data, work_led);
>> +
>> + mutex_lock(&powernv_led->lock);
>> + powernv_led_set(powernv_led);
>> + mutex_unlock(&powernv_led->lock);
>> +}
>> +
>> +/*
>> + * LED classdev 'brightness_get' function. This schedules work
>> + * to update LED state.
>> + */
>> +static void powernv_brightness_set(struct led_classdev *led_cdev,
>> + enum led_brightness value)
>> +{
>> + struct powernv_led_data *powernv_led =
>> + container_of(led_cdev, struct powernv_led_data, cdev);
>> +
>> + /* Do not modify LED in unload path */
>> + if (led_disabled)
>> + return;
>> +
>> + /* Prepare the request */
>> + powernv_led->value = value;
>> +
>> + /* Schedule the new task */
>> + schedule_work(&powernv_led->work_led);
>> +}
>> +
>> +/* LED classdev 'brightness_get' function */
>> +static enum led_brightness
>> +powernv_brightness_get(struct led_classdev *led_cdev)
>> +{
>> + struct powernv_led_data *powernv_led =
>> + container_of(led_cdev, struct powernv_led_data, cdev);
>> +
>> + return powernv_led_get(powernv_led);
>> +}
>> +
>> +
>> +/*
>> + * This function registers classdev structure for any given type of LED on
>> + * a given child LED device node.
>> + */
>> +static int powernv_led_create(struct device *dev,
>> + struct powernv_led_data *powernv_led,
>> + const char *led_name, const char *led_type_desc)
>> +{
>> + int rc;
>> +
>> + /* Make sure LED type is supported */
>> + powernv_led->led_type = powernv_get_led_type(led_type_desc);
>> + if (powernv_led->led_type == -1) {
>> + dev_warn(dev, "%s: No support for led type : %s\n",
>> + __func__, led_type_desc);
>> + return -EINVAL;
>> + }
>> +
>> + /* Location code of the LED */
>> + powernv_led->loc_code = kasprintf(GFP_KERNEL, "%s", led_name);
>
> DT node name is available all the time, you don't need another variable
> for it.
Yes.. But then we have to traverse through DT node get location code in
powernv_led_get() and powernv_led_set() function. something like
for_each_child_of_node(led_node, np) {
if (!strstr(np->name, powernv_led->cdev.name) {
/* Process get/set LED */
break;
}
}
Hence I thought of adding that to structure itself.
-Vasant
>
>> + if (!powernv_led->loc_code) {
>> + dev_err(dev, "%s: Memory allocation failed\n", __func__);
>> + return -ENOMEM;
>> + }
>> +
>> + /* Create the name for classdev */
>> + powernv_led->cdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
>> + led_name, led_type_desc);
>> + if (!powernv_led->cdev.name) {
>> + dev_err(dev,
>> + "%s: Memory allocation failed for classdev name\n",
>> + __func__);
>> + kfree(powernv_led->loc_code);
>> + return -ENOMEM;
>> + }
>> +
>> + powernv_led->cdev.brightness_set = powernv_brightness_set;
>> + powernv_led->cdev.brightness_get = powernv_brightness_get;
>> + powernv_led->cdev.brightness = LED_OFF;
>> + powernv_led->cdev.max_brightness = LED_FULL;
>> +
>> + mutex_init(&powernv_led->lock);
>> + INIT_WORK(&powernv_led->work_led, powernv_deferred_led_set);
>> +
>> + /* Register the classdev */
>> + rc = devm_led_classdev_register(dev, &powernv_led->cdev);
>> + if (rc) {
>> + dev_err(dev, "%s: Classdev registration failed for %s\n",
>> + __func__, powernv_led->cdev.name);
>> + kfree(powernv_led->loc_code);
>> + kfree(powernv_led->cdev.name);
>> + }
>> +
>> + return rc;
>> +}
>> +
>> +/* Go through LED device tree node and register LED classdev structure */
>> +static int powernv_led_classdev(struct platform_device *pdev,
>> + struct device_node *led_node,
>> + struct powernv_leds_priv *priv, int num_leds)
>> +{
>> + const char *cur = NULL;
>> + int i, rc = -1;
>> + struct property *p;
>> + struct device_node *np;
>> + struct powernv_led_data *powernv_led;
>> + struct device *dev = &pdev->dev;
>> +
>> + for_each_child_of_node(led_node, np) {
>> + p = of_find_property(np, "led-types", NULL);
>> + if (!p)
>> + continue;
>> +
>> + while ((cur = of_prop_next_string(p, cur)) != NULL) {
>> + powernv_led = &priv->powernv_leds[priv->num_leds++];
>> + if (priv->num_leds > num_leds) {
>> + rc = -ENOMEM;
>> + goto classdev_fail;
>> + }
>> + rc = powernv_led_create(dev,
>> + powernv_led, np->name, cur);
>> + if (rc)
>> + goto classdev_fail;
>> + } /* while end */
>> + }
>> +
>> + platform_set_drvdata(pdev, priv);
>> + return rc;
>> +
>> +classdev_fail:
>> + for (i = priv->num_leds - 2; i >= 0; i--) {
>> + powernv_led = &priv->powernv_leds[i];
>> + devm_led_classdev_unregister(dev, &powernv_led->cdev);
>> + kfree(powernv_led->loc_code);
>> + mutex_destroy(&powernv_led->lock);
>> + }
>> +
>> + return rc;
>> +}
>> +
>> +/*
>> + * We want to populate LED device for each LED type. Hence we
>> + * have to calculate count explicitly.
>> + */
>> +static int powernv_leds_count(struct device_node *led_node)
>> +{
>> + const char *cur = NULL;
>> + int num_leds = 0;
>> + struct property *p;
>> + struct device_node *np;
>> +
>> + for_each_child_of_node(led_node, np) {
>> + p = of_find_property(np, "led-types", NULL);
>> + if (!p)
>> + continue;
>> +
>> + while ((cur = of_prop_next_string(p, cur)) != NULL)
>> + num_leds++;
>> + }
>> +
>> + return num_leds;
>> +}
>> +
>> +/* Platform driver probe */
>> +static int powernv_led_probe(struct platform_device *pdev)
>> +{
>> + int num_leds;
>> + struct device_node *led_node;
>> + struct powernv_leds_priv *priv;
>> +
>> + led_node = of_find_node_by_path("/ibm,opal/leds");
>> + if (!led_node) {
>> + dev_err(&pdev->dev,
>> + "%s: LED parent device node not found\n", __func__);
>> + return -EINVAL;
>> + }
>> +
>> + num_leds = powernv_leds_count(led_node);
>> + if (num_leds <= 0) {
>> + dev_err(&pdev->dev,
>> + "%s: No location code found under LED node\n",
>> + __func__);
>> + return -EINVAL;
>> + }
>> +
>> + priv = devm_kzalloc(&pdev->dev,
>> + sizeof_powernv_leds_priv(num_leds), GFP_KERNEL);
>> + if (!priv)
>> + return -ENOMEM;
>> +
>> + return powernv_led_classdev(pdev, led_node, priv, num_leds);
>> +}
>> +
>> +/* Platform driver remove */
>> +static int powernv_led_remove(struct platform_device *pdev)
>> +{
>> + int i;
>> + struct powernv_led_data *powernv_led;
>> + struct powernv_leds_priv *priv;
>> +
>> + /* Disable LED operation */
>> + led_disabled = true;
>> +
>> + priv = platform_get_drvdata(pdev);
>> +
>> + for (i = 0; i < priv->num_leds; i++) {
>> + powernv_led = &priv->powernv_leds[i];
>> + devm_led_classdev_unregister(&pdev->dev, &powernv_led->cdev);
>> + flush_work(&powernv_led->work_led);
>> + kfree(powernv_led->loc_code);
>> + mutex_destroy(&powernv_led->lock);
>> + }
>> +
>> + dev_info(&pdev->dev, "PowerNV led module unregistered\n");
>> + return 0;
>> +}
>> +
>> +/* Platform driver property match */
>> +static const struct of_device_id powernv_led_match[] = {
>> + {
>> + .compatible = "ibm,opal-v3-led",
>> + },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, powernv_led_match);
>> +
>> +static struct platform_driver powernv_led_driver = {
>> + .probe = powernv_led_probe,
>> + .remove = powernv_led_remove,
>> + .driver = {
>> + .name = "powernv-led-driver",
>> + .owner = THIS_MODULE,
>> + .of_match_table = powernv_led_match,
>> + },
>> +};
>> +
>> +module_platform_driver(powernv_led_driver);
>> +
>> +MODULE_LICENSE("GPL");
>
> If you want to be consistent with what you declare in the beginnig
> then it should be:
>
> MODULE_LICENSE("GPL v2")
Fixed.
Thanks!
-Vasant
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