drivers/input/keyboard/sh_keysc.c

Source file repositories/reference/linux-study-clean/drivers/input/keyboard/sh_keysc.c

File Facts

System
Linux kernel
Corpus path
drivers/input/keyboard/sh_keysc.c
Extension
.c
Size
7880 bytes
Lines
333
Domain
Driver Families
Bucket
drivers/input
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.

Dependency Surface

Detected Declarations

Annotated Snippet

struct sh_keysc_priv {
	void __iomem *iomem_base;
	DECLARE_BITMAP(last_keys, SH_KEYSC_MAXKEYS);
	struct input_dev *input;
	struct sh_keysc_info pdata;
};

#define KYCR1 0
#define KYCR2 1
#define KYINDR 2
#define KYOUTDR 3

#define KYCR2_IRQ_LEVEL    0x10
#define KYCR2_IRQ_DISABLED 0x00

static unsigned long sh_keysc_read(struct sh_keysc_priv *p, int reg_nr)
{
	return ioread16(p->iomem_base + (reg_nr << 2));
}

static void sh_keysc_write(struct sh_keysc_priv *p, int reg_nr,
			   unsigned long value)
{
	iowrite16(value, p->iomem_base + (reg_nr << 2));
}

static void sh_keysc_level_mode(struct sh_keysc_priv *p,
				unsigned long keys_set)
{
	struct sh_keysc_info *pdata = &p->pdata;

	sh_keysc_write(p, KYOUTDR, 0);
	sh_keysc_write(p, KYCR2, KYCR2_IRQ_LEVEL | (keys_set << 8));

	if (pdata->kycr2_delay)
		udelay(pdata->kycr2_delay);
}

static void sh_keysc_map_dbg(struct device *dev, unsigned long *map,
			     const char *str)
{
	int k;

	for (k = 0; k < BITS_TO_LONGS(SH_KEYSC_MAXKEYS); k++)
		dev_dbg(dev, "%s[%d] 0x%lx\n", str, k, map[k]);
}

static irqreturn_t sh_keysc_isr(int irq, void *dev_id)
{
	struct platform_device *pdev = dev_id;
	struct sh_keysc_priv *priv = platform_get_drvdata(pdev);
	struct sh_keysc_info *pdata = &priv->pdata;
	int keyout_nr = sh_keysc_mode[pdata->mode].keyout;
	int keyin_nr = sh_keysc_mode[pdata->mode].keyin;
	DECLARE_BITMAP(keys, SH_KEYSC_MAXKEYS);
	DECLARE_BITMAP(keys0, SH_KEYSC_MAXKEYS);
	DECLARE_BITMAP(keys1, SH_KEYSC_MAXKEYS);
	unsigned char keyin_set, tmp;
	int i, k, n;

	dev_dbg(&pdev->dev, "isr!\n");

	bitmap_fill(keys1, SH_KEYSC_MAXKEYS);
	bitmap_zero(keys0, SH_KEYSC_MAXKEYS);

	do {
		bitmap_zero(keys, SH_KEYSC_MAXKEYS);
		keyin_set = 0;

		sh_keysc_write(priv, KYCR2, KYCR2_IRQ_DISABLED);

		for (i = 0; i < keyout_nr; i++) {
			n = keyin_nr * i;

			/* drive one KEYOUT pin low, read KEYIN pins */
			sh_keysc_write(priv, KYOUTDR, 0xffff ^ (3 << (i * 2)));
			udelay(pdata->delay);
			tmp = sh_keysc_read(priv, KYINDR);

			/* set bit if key press has been detected */
			for (k = 0; k < keyin_nr; k++) {
				if (tmp & (1 << k))
					__set_bit(n + k, keys);
			}

			/* keep track of which KEYIN bits that have been set */
			keyin_set |= tmp ^ ((1 << keyin_nr) - 1);
		}

		sh_keysc_level_mode(priv, keyin_set);

Annotation

Implementation Notes