I.MX6 SD卡热插拔的识别过程
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2022-04-28 08:00:41
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前言
内核版本:3.0,35
识别流程
**arch/arm/mach-mx6/board-mx6q_sabresd.c **
imx6q_add_sdhci_usdhc_imx(2, &mx6q_sabresd_sd3_data);
static const struct esdhc_platform_data mx6q_sabresd_sd3_data __initconst = {
.cd_gpio = SABRESD_SD3_CD,
//.wp_gpio = SABRESD_SD3_WP,
.wp_gpio = -EINVAL,
.keep_power_at_suspend = 1,
.support_8bit = 0,
.delay_line = 0,
.cd_type = ESDHC_CD_GPIO,
.runtime_pm = 1,
};
#define SABRESD_SD3_CD IMX_GPIO_NR(7, 1)
需要将cd_gpio配置成GPIO模式
arch/arm/mach-mx6/board-mx6q_sabresd.h
MX6Q_PAD_SD3_DAT4__GPIO_7_1, /* SD3_CD */
流程:
mmc/host/sdhci-esdhc-imx.c //插入SD卡 就会触发中断cd_irq
esdhc_pltfm_init()->request_irq(gpio_to_irq(boarddata->cd_gpio), cd_irq.....)-> cd_irq()->tasklet_schedule(&sdhost->card_tasklet)
mmc/host/sdhci.c
tasklet_init(&host->card_tasklet,sdhci_tasklet_card, (unsigned long)host) -> sdhci_tasklet_card() -> mmc_detect_change()
mmc/core/core.c
mmc_detect_change() -> mmc_schedule_delayed_work(&host->detect, delay)
mmc/core/host.c
mmc_alloc_host()-> INIT_DELAYED_WORK(&host->detect, mmc_rescan)
mmc/core/core.c
mmc_rescan()-> mmc_rescan_try_freq()-> mmc_attach_sd(host)
mmc/core/sd.c
mmc_attach_sd()->mmc_add_card()
mmc/core/bus.c
mmc_add_card()-> printk(KERN_INFO "%s: new %s%s%s card at address %04x\n"
mmc1: new high speed SDHC card at address 0001
android 自动挂载
device/fsl/sabresd_6dq/fstab.freescale
/devices/platform/sdhci-esdhc-imx.2/mmc_host/mmc1 /mnt/media_rw/extsd exfat defaults voldmanaged=extsd:auto