英文符号读法
和 i2c_set_clientdata 配对使用,简单说,就是通过这两个接口来在驱动的回调中获取用户私有的结构体指针。
/**
value on the error condition.
/
static inline int of_get_gpio(const struct device_node np, int index)
{
return of_get_gpio_flags(np, index, NULL);
}
这个index 表示gpios节点的索引位置,gpios支持多个节点,每个节点由<gpio_chip gpio_num default_level>
eg:
gpios = <&ap_gpio 145 0 &ap_gpio 144 0>;
网络制式定义,不局限于安卓。
ro.telephony.default_network
可选值:
/* NETWORK_MODE_* See ril.h RIL_REQUEST_SET_PREFERRED_NETWORK_TYPE */
int NETWORK_MODE_WCDMA_PREF = 0; /* GSM/WCDMA (WCDMA preferred) */
int NETWORK_MODE_GSM_ONLY = 1; /* GSM only */
int NETWORK_MODE_WCDMA_ONLY = 2; /* WCDMA only */
int NETWORK_MODE_GSM_UMTS = 3; /* GSM/WCDMA (auto mode, according to PRL)
AVAILABLE Application Settings menu*/
int NETWORK_MODE_CDMA = 4; /* CDMA and EvDo (auto mode, according to PRL)
AVAILABLE Application Settings menu*/
int NETWORK_MODE_CDMA_NO_EVDO = 5; /* CDMA only */
int NETWORK_MODE_EVDO_NO_CDMA = 6; /* EvDo only */
int NETWORK_MODE_GLOBAL = 7; /* GSM/WCDMA, CDMA, and EvDo (auto mode, according to PRL)
AVAILABLE Application Settings menu*/
int NETWORK_MODE_LTE_CDMA_EVDO = 8; /* LTE, CDMA and EvDo */
int NETWORK_MODE_LTE_GSM_WCDMA = 9; /* LTE, GSM/WCDMA */
int NETWORK_MODE_LTE_CMDA_EVDO_GSM_WCDMA = 10; /* LTE, CDMA, EvDo, GSM/WCDMA */
int NETWORK_MODE_LTE_ONLY = 11; /* LTE Only mode. */
int NETWORK_MODE_LTE_WCDMA = 12; /* LTE/WCDMA */
int NETWORK_MODE_TD_SCDMA_ONLY = 13; /* TD-SCDMA only */
int NETWORK_MODE_TD_SCDMA_WCDMA = 14; /* TD-SCDMA and WCDMA */
int NETWORK_MODE_TD_SCDMA_LTE = 15; /* TD-SCDMA and LTE */
int NETWORK_MODE_TD_SCDMA_GSM = 16; /* TD-SCDMA and GSM */
int NETWORK_MODE_TD_SCDMA_GSM_LTE = 17; /* TD-SCDMA,GSM and LTE */
int NETWORK_MODE_TD_SCDMA_GSM_WCDMA = 18; /* TD-SCDMA, GSM/WCDMA */
int NETWORK_MODE_TD_SCDMA_WCDMA_LTE = 19; /* TD-SCDMA, WCDMA and LTE */
int NETWORK_MODE_TD_SCDMA_GSM_WCDMA_LTE = 20; /* TD-SCDMA, GSM/WCDMA and LTE */
int NETWORK_MODE_TD_SCDMA_CDMA_EVDO_GSM_WCDMA = 21; /*TD-SCDMA,EvDo,CDMA,GSM/WCDMA*/
int NETWORK_MODE_TD_SCDMA_LTE_CDMA_EVDO_GSM_WCDMA = 22; /* TD-SCDMA/LTE/GSM/WCDMA, CDMA, and EvDo */
嵌入式中,我们可以通过x509证书来实现tcp+tls或者https,那么如何处理过期的问题呢?
这个过程对终端都是类似的行为,下载,更新,但是根据服务器实现的技术不同,可以分为以下两种:
当没屏幕时,通过adb调节音量就有用了:
set:
adb shell media volume --show --stream 0 --set 15
get:
adb shell media volume --stream 0 --get
stream 类型参考
AUDIO_STREAM_VOICE_CALL = 0,
AUDIO_STREAM_SYSTEM = 1,
AUDIO_STREAM_RING = 2,
AUDIO_STREAM_MUSIC = 3,
AUDIO_STREAM_ALARM = 4,
AUDIO_STREAM_NOTIFICATION = 5,
AUDIO_STREAM_BLUETOOTH_SCO = 6,
AUDIO_STREAM_ENFORCED_AUDIBLE = 7,
AUDIO_STREAM_DTMF = 8,
AUDIO_STREAM_TTS = 9,
AUDIO_STREAM_ACCESSIBILITY = 10
作为十多年的c开发者,仍然可以找到知识的细节和盲区,推荐给每一个c的学习者
目前暂无定位结果,暂怀疑是内存问题,待定位了再来更新。