drivers/extcon/extcon-palmas.c
Source file repositories/reference/linux-study-clean/drivers/extcon/extcon-palmas.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/extcon/extcon-palmas.c- Extension
.c- Size
- 13383 bytes
- Lines
- 434
- Domain
- Driver Families
- Bucket
- drivers/extcon
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/devm-helpers.hlinux/module.hlinux/interrupt.hlinux/platform_device.hlinux/slab.hlinux/err.hlinux/mfd/palmas.hlinux/of.hlinux/of_platform.hlinux/gpio/consumer.hlinux/workqueue.h
Detected Declarations
function palmas_usb_wakeupfunction palmas_vbus_irq_handlerfunction palmas_id_irq_handlerfunction palmas_gpio_id_detectfunction palmas_gpio_id_irq_handlerfunction palmas_enable_irqfunction palmas_usb_probefunction palmas_usb_suspendfunction palmas_usb_resume
Annotated Snippet
if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
extcon_set_state_sync(edev, EXTCON_USB, true);
dev_dbg(palmas_usb->dev, "USB cable is attached\n");
} else {
dev_dbg(palmas_usb->dev,
"Spurious connect event detected\n");
}
} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
extcon_set_state_sync(edev, EXTCON_USB, false);
dev_dbg(palmas_usb->dev, "USB cable is detached\n");
} else {
dev_dbg(palmas_usb->dev,
"Spurious disconnect event detected\n");
}
}
return IRQ_HANDLED;
}
static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
{
unsigned int set, id_src;
struct palmas_usb *palmas_usb = _palmas_usb;
struct extcon_dev *edev = palmas_usb->edev;
palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
PALMAS_USB_ID_INT_LATCH_SET, &set);
palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
PALMAS_USB_ID_INT_SRC, &id_src);
if ((set & PALMAS_USB_ID_INT_SRC_ID_GND) &&
(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
PALMAS_USB_ID_INT_LATCH_CLR,
PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
palmas_usb->linkstat = PALMAS_USB_STATE_ID;
extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
dev_dbg(palmas_usb->dev, "USB-HOST cable is attached\n");
} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
PALMAS_USB_ID_INT_LATCH_CLR,
PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
palmas_usb->linkstat = PALMAS_USB_STATE_ID;
extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
dev_dbg(palmas_usb->dev, "USB-HOST cable is attached\n");
}
return IRQ_HANDLED;
}
static void palmas_gpio_id_detect(struct work_struct *work)
{
int id;
struct palmas_usb *palmas_usb = container_of(to_delayed_work(work),
struct palmas_usb,
wq_detectid);
struct extcon_dev *edev = palmas_usb->edev;
if (!palmas_usb->id_gpiod)
return;
id = gpiod_get_value_cansleep(palmas_usb->id_gpiod);
if (id) {
extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
} else {
extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
dev_dbg(palmas_usb->dev, "USB-HOST cable is attached\n");
}
}
static irqreturn_t palmas_gpio_id_irq_handler(int irq, void *_palmas_usb)
{
struct palmas_usb *palmas_usb = _palmas_usb;
Annotation
- Immediate include surface: `linux/devm-helpers.h`, `linux/module.h`, `linux/interrupt.h`, `linux/platform_device.h`, `linux/slab.h`, `linux/err.h`, `linux/mfd/palmas.h`, `linux/of.h`.
- Detected declarations: `function palmas_usb_wakeup`, `function palmas_vbus_irq_handler`, `function palmas_id_irq_handler`, `function palmas_gpio_id_detect`, `function palmas_gpio_id_irq_handler`, `function palmas_enable_irq`, `function palmas_usb_probe`, `function palmas_usb_suspend`, `function palmas_usb_resume`.
- Atlas domain: Driver Families / drivers/extcon.
- Implementation status: source implementation candidate.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.